diff options
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/staging/Kconfig | 2 | ||||
-rw-r--r-- | drivers/staging/Makefile | 1 | ||||
-rw-r--r-- | drivers/staging/echo/Kconfig | 9 | ||||
-rw-r--r-- | drivers/staging/echo/Makefile | 1 | ||||
-rw-r--r-- | drivers/staging/echo/TODO | 10 | ||||
-rw-r--r-- | drivers/staging/echo/bit_operations.h | 253 | ||||
-rw-r--r-- | drivers/staging/echo/echo.c | 632 | ||||
-rw-r--r-- | drivers/staging/echo/echo.h | 220 | ||||
-rw-r--r-- | drivers/staging/echo/fir.h | 369 | ||||
-rw-r--r-- | drivers/staging/echo/mmx.h | 288 |
10 files changed, 1785 insertions, 0 deletions
diff --git a/drivers/staging/Kconfig b/drivers/staging/Kconfig index 762b471fdeda..25338b7eac98 100644 --- a/drivers/staging/Kconfig +++ b/drivers/staging/Kconfig | |||
@@ -39,4 +39,6 @@ source "drivers/staging/winbond/Kconfig" | |||
39 | 39 | ||
40 | source "drivers/staging/wlan-ng/Kconfig" | 40 | source "drivers/staging/wlan-ng/Kconfig" |
41 | 41 | ||
42 | source "drivers/staging/echo/Kconfig" | ||
43 | |||
42 | endif # STAGING | 44 | endif # STAGING |
diff --git a/drivers/staging/Makefile b/drivers/staging/Makefile index 574198479d66..93decb89b1d8 100644 --- a/drivers/staging/Makefile +++ b/drivers/staging/Makefile | |||
@@ -8,3 +8,4 @@ obj-$(CONFIG_VIDEO_GO7007) += go7007/ | |||
8 | obj-$(CONFIG_USB_IP_COMMON) += usbip/ | 8 | obj-$(CONFIG_USB_IP_COMMON) += usbip/ |
9 | obj-$(CONFIG_W35UND) += winbond/ | 9 | obj-$(CONFIG_W35UND) += winbond/ |
10 | obj-$(CONFIG_PRISM2_USB) += wlan-ng/ | 10 | obj-$(CONFIG_PRISM2_USB) += wlan-ng/ |
11 | obj-$(CONFIG_ECHO) += echo/ | ||
diff --git a/drivers/staging/echo/Kconfig b/drivers/staging/echo/Kconfig new file mode 100644 index 000000000000..f1d41ea9cd48 --- /dev/null +++ b/drivers/staging/echo/Kconfig | |||
@@ -0,0 +1,9 @@ | |||
1 | config ECHO | ||
2 | tristate "Line Echo Canceller support" | ||
3 | default n | ||
4 | ---help--- | ||
5 | This driver provides line echo cancelling support for mISDN and | ||
6 | Zaptel drivers. | ||
7 | |||
8 | To compile this driver as a module, choose M here. The module | ||
9 | will be called echo. | ||
diff --git a/drivers/staging/echo/Makefile b/drivers/staging/echo/Makefile new file mode 100644 index 000000000000..7d4caac12a8d --- /dev/null +++ b/drivers/staging/echo/Makefile | |||
@@ -0,0 +1 @@ | |||
obj-$(CONFIG_ECHO) += echo.o | |||
diff --git a/drivers/staging/echo/TODO b/drivers/staging/echo/TODO new file mode 100644 index 000000000000..1ca09afd603e --- /dev/null +++ b/drivers/staging/echo/TODO | |||
@@ -0,0 +1,10 @@ | |||
1 | TODO: | ||
2 | - checkpatch.pl cleanups | ||
3 | - Lindent | ||
4 | - typedef removals | ||
5 | - handle bit_operations.h (merge in or make part of common code?) | ||
6 | - remove proc interface, only use echo.h interface (proc interface is | ||
7 | racy and not correct.) | ||
8 | |||
9 | Please send patches to Greg Kroah-Hartman <greg@kroah.com> and Cc: Steve | ||
10 | Underwood <steveu@coppice.org> and David Rowe <david@rowetel.com> | ||
diff --git a/drivers/staging/echo/bit_operations.h b/drivers/staging/echo/bit_operations.h new file mode 100644 index 000000000000..b32f4bf99397 --- /dev/null +++ b/drivers/staging/echo/bit_operations.h | |||
@@ -0,0 +1,253 @@ | |||
1 | /* | ||
2 | * SpanDSP - a series of DSP components for telephony | ||
3 | * | ||
4 | * bit_operations.h - Various bit level operations, such as bit reversal | ||
5 | * | ||
6 | * Written by Steve Underwood <steveu@coppice.org> | ||
7 | * | ||
8 | * Copyright (C) 2006 Steve Underwood | ||
9 | * | ||
10 | * All rights reserved. | ||
11 | * | ||
12 | * This program is free software; you can redistribute it and/or modify | ||
13 | * it under the terms of the GNU General Public License version 2, as | ||
14 | * published by the Free Software Foundation. | ||
15 | * | ||
16 | * This program is distributed in the hope that it will be useful, | ||
17 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
18 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
19 | * GNU General Public License for more details. | ||
20 | * | ||
21 | * You should have received a copy of the GNU General Public License | ||
22 | * along with this program; if not, write to the Free Software | ||
23 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | ||
24 | * | ||
25 | * $Id: bit_operations.h,v 1.11 2006/11/28 15:37:03 steveu Exp $ | ||
26 | */ | ||
27 | |||
28 | /*! \file */ | ||
29 | |||
30 | #if !defined(_BIT_OPERATIONS_H_) | ||
31 | #define _BIT_OPERATIONS_H_ | ||
32 | |||
33 | #ifdef __cplusplus | ||
34 | extern "C" { | ||
35 | #endif | ||
36 | |||
37 | #if defined(__i386__) || defined(__x86_64__) | ||
38 | /*! \brief Find the bit position of the highest set bit in a word | ||
39 | \param bits The word to be searched | ||
40 | \return The bit number of the highest set bit, or -1 if the word is zero. */ | ||
41 | static __inline__ int top_bit(unsigned int bits) | ||
42 | { | ||
43 | int res; | ||
44 | |||
45 | __asm__ (" xorl %[res],%[res];\n" | ||
46 | " decl %[res];\n" | ||
47 | " bsrl %[bits],%[res]\n" | ||
48 | : [res] "=&r" (res) | ||
49 | : [bits] "rm" (bits)); | ||
50 | return res; | ||
51 | } | ||
52 | /*- End of function --------------------------------------------------------*/ | ||
53 | |||
54 | /*! \brief Find the bit position of the lowest set bit in a word | ||
55 | \param bits The word to be searched | ||
56 | \return The bit number of the lowest set bit, or -1 if the word is zero. */ | ||
57 | static __inline__ int bottom_bit(unsigned int bits) | ||
58 | { | ||
59 | int res; | ||
60 | |||
61 | __asm__ (" xorl %[res],%[res];\n" | ||
62 | " decl %[res];\n" | ||
63 | " bsfl %[bits],%[res]\n" | ||
64 | : [res] "=&r" (res) | ||
65 | : [bits] "rm" (bits)); | ||
66 | return res; | ||
67 | } | ||
68 | /*- End of function --------------------------------------------------------*/ | ||
69 | #else | ||
70 | static __inline__ int top_bit(unsigned int bits) | ||
71 | { | ||
72 | int i; | ||
73 | |||
74 | if (bits == 0) | ||
75 | return -1; | ||
76 | i = 0; | ||
77 | if (bits & 0xFFFF0000) | ||
78 | { | ||
79 | bits &= 0xFFFF0000; | ||
80 | i += 16; | ||
81 | } | ||
82 | if (bits & 0xFF00FF00) | ||
83 | { | ||
84 | bits &= 0xFF00FF00; | ||
85 | i += 8; | ||
86 | } | ||
87 | if (bits & 0xF0F0F0F0) | ||
88 | { | ||
89 | bits &= 0xF0F0F0F0; | ||
90 | i += 4; | ||
91 | } | ||
92 | if (bits & 0xCCCCCCCC) | ||
93 | { | ||
94 | bits &= 0xCCCCCCCC; | ||
95 | i += 2; | ||
96 | } | ||
97 | if (bits & 0xAAAAAAAA) | ||
98 | { | ||
99 | bits &= 0xAAAAAAAA; | ||
100 | i += 1; | ||
101 | } | ||
102 | return i; | ||
103 | } | ||
104 | /*- End of function --------------------------------------------------------*/ | ||
105 | |||
106 | static __inline__ int bottom_bit(unsigned int bits) | ||
107 | { | ||
108 | int i; | ||
109 | |||
110 | if (bits == 0) | ||
111 | return -1; | ||
112 | i = 32; | ||
113 | if (bits & 0x0000FFFF) | ||
114 | { | ||
115 | bits &= 0x0000FFFF; | ||
116 | i -= 16; | ||
117 | } | ||
118 | if (bits & 0x00FF00FF) | ||
119 | { | ||
120 | bits &= 0x00FF00FF; | ||
121 | i -= 8; | ||
122 | } | ||
123 | if (bits & 0x0F0F0F0F) | ||
124 | { | ||
125 | bits &= 0x0F0F0F0F; | ||
126 | i -= 4; | ||
127 | } | ||
128 | if (bits & 0x33333333) | ||
129 | { | ||
130 | bits &= 0x33333333; | ||
131 | i -= 2; | ||
132 | } | ||
133 | if (bits & 0x55555555) | ||
134 | { | ||
135 | bits &= 0x55555555; | ||
136 | i -= 1; | ||
137 | } | ||
138 | return i; | ||
139 | } | ||
140 | /*- End of function --------------------------------------------------------*/ | ||
141 | #endif | ||
142 | |||
143 | /*! \brief Bit reverse a byte. | ||
144 | \param data The byte to be reversed. | ||
145 | \return The bit reversed version of data. */ | ||
146 | static __inline__ uint8_t bit_reverse8(uint8_t x) | ||
147 | { | ||
148 | #if defined(__i386__) || defined(__x86_64__) | ||
149 | /* If multiply is fast */ | ||
150 | return ((x*0x0802U & 0x22110U) | (x*0x8020U & 0x88440U))*0x10101U >> 16; | ||
151 | #else | ||
152 | /* If multiply is slow, but we have a barrel shifter */ | ||
153 | x = (x >> 4) | (x << 4); | ||
154 | x = ((x & 0xCC) >> 2) | ((x & 0x33) << 2); | ||
155 | return ((x & 0xAA) >> 1) | ((x & 0x55) << 1); | ||
156 | #endif | ||
157 | } | ||
158 | /*- End of function --------------------------------------------------------*/ | ||
159 | |||
160 | /*! \brief Bit reverse a 16 bit word. | ||
161 | \param data The word to be reversed. | ||
162 | \return The bit reversed version of data. */ | ||
163 | uint16_t bit_reverse16(uint16_t data); | ||
164 | |||
165 | /*! \brief Bit reverse a 32 bit word. | ||
166 | \param data The word to be reversed. | ||
167 | \return The bit reversed version of data. */ | ||
168 | uint32_t bit_reverse32(uint32_t data); | ||
169 | |||
170 | /*! \brief Bit reverse each of the four bytes in a 32 bit word. | ||
171 | \param data The word to be reversed. | ||
172 | \return The bit reversed version of data. */ | ||
173 | uint32_t bit_reverse_4bytes(uint32_t data); | ||
174 | |||
175 | /*! \brief Find the number of set bits in a 32 bit word. | ||
176 | \param x The word to be searched. | ||
177 | \return The number of set bits. */ | ||
178 | int one_bits32(uint32_t x); | ||
179 | |||
180 | /*! \brief Create a mask as wide as the number in a 32 bit word. | ||
181 | \param x The word to be searched. | ||
182 | \return The mask. */ | ||
183 | uint32_t make_mask32(uint32_t x); | ||
184 | |||
185 | /*! \brief Create a mask as wide as the number in a 16 bit word. | ||
186 | \param x The word to be searched. | ||
187 | \return The mask. */ | ||
188 | uint16_t make_mask16(uint16_t x); | ||
189 | |||
190 | /*! \brief Find the least significant one in a word, and return a word | ||
191 | with just that bit set. | ||
192 | \param x The word to be searched. | ||
193 | \return The word with the single set bit. */ | ||
194 | static __inline__ uint32_t least_significant_one32(uint32_t x) | ||
195 | { | ||
196 | return (x & (-(int32_t) x)); | ||
197 | } | ||
198 | /*- End of function --------------------------------------------------------*/ | ||
199 | |||
200 | /*! \brief Find the most significant one in a word, and return a word | ||
201 | with just that bit set. | ||
202 | \param x The word to be searched. | ||
203 | \return The word with the single set bit. */ | ||
204 | static __inline__ uint32_t most_significant_one32(uint32_t x) | ||
205 | { | ||
206 | #if defined(__i386__) || defined(__x86_64__) | ||
207 | return 1 << top_bit(x); | ||
208 | #else | ||
209 | x = make_mask32(x); | ||
210 | return (x ^ (x >> 1)); | ||
211 | #endif | ||
212 | } | ||
213 | /*- End of function --------------------------------------------------------*/ | ||
214 | |||
215 | /*! \brief Find the parity of a byte. | ||
216 | \param x The byte to be checked. | ||
217 | \return 1 for odd, or 0 for even. */ | ||
218 | static __inline__ int parity8(uint8_t x) | ||
219 | { | ||
220 | x = (x ^ (x >> 4)) & 0x0F; | ||
221 | return (0x6996 >> x) & 1; | ||
222 | } | ||
223 | /*- End of function --------------------------------------------------------*/ | ||
224 | |||
225 | /*! \brief Find the parity of a 16 bit word. | ||
226 | \param x The word to be checked. | ||
227 | \return 1 for odd, or 0 for even. */ | ||
228 | static __inline__ int parity16(uint16_t x) | ||
229 | { | ||
230 | x ^= (x >> 8); | ||
231 | x = (x ^ (x >> 4)) & 0x0F; | ||
232 | return (0x6996 >> x) & 1; | ||
233 | } | ||
234 | /*- End of function --------------------------------------------------------*/ | ||
235 | |||
236 | /*! \brief Find the parity of a 32 bit word. | ||
237 | \param x The word to be checked. | ||
238 | \return 1 for odd, or 0 for even. */ | ||
239 | static __inline__ int parity32(uint32_t x) | ||
240 | { | ||
241 | x ^= (x >> 16); | ||
242 | x ^= (x >> 8); | ||
243 | x = (x ^ (x >> 4)) & 0x0F; | ||
244 | return (0x6996 >> x) & 1; | ||
245 | } | ||
246 | /*- End of function --------------------------------------------------------*/ | ||
247 | |||
248 | #ifdef __cplusplus | ||
249 | } | ||
250 | #endif | ||
251 | |||
252 | #endif | ||
253 | /*- End of file ------------------------------------------------------------*/ | ||
diff --git a/drivers/staging/echo/echo.c b/drivers/staging/echo/echo.c new file mode 100644 index 000000000000..4a281b14fc58 --- /dev/null +++ b/drivers/staging/echo/echo.c | |||
@@ -0,0 +1,632 @@ | |||
1 | /* | ||
2 | * SpanDSP - a series of DSP components for telephony | ||
3 | * | ||
4 | * echo.c - A line echo canceller. This code is being developed | ||
5 | * against and partially complies with G168. | ||
6 | * | ||
7 | * Written by Steve Underwood <steveu@coppice.org> | ||
8 | * and David Rowe <david_at_rowetel_dot_com> | ||
9 | * | ||
10 | * Copyright (C) 2001, 2003 Steve Underwood, 2007 David Rowe | ||
11 | * | ||
12 | * Based on a bit from here, a bit from there, eye of toad, ear of | ||
13 | * bat, 15 years of failed attempts by David and a few fried brain | ||
14 | * cells. | ||
15 | * | ||
16 | * All rights reserved. | ||
17 | * | ||
18 | * This program is free software; you can redistribute it and/or modify | ||
19 | * it under the terms of the GNU General Public License version 2, as | ||
20 | * published by the Free Software Foundation. | ||
21 | * | ||
22 | * This program is distributed in the hope that it will be useful, | ||
23 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
24 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
25 | * GNU General Public License for more details. | ||
26 | * | ||
27 | * You should have received a copy of the GNU General Public License | ||
28 | * along with this program; if not, write to the Free Software | ||
29 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | ||
30 | * | ||
31 | * $Id: echo.c,v 1.20 2006/12/01 18:00:48 steveu Exp $ | ||
32 | */ | ||
33 | |||
34 | /*! \file */ | ||
35 | |||
36 | /* Implementation Notes | ||
37 | David Rowe | ||
38 | April 2007 | ||
39 | |||
40 | This code started life as Steve's NLMS algorithm with a tap | ||
41 | rotation algorithm to handle divergence during double talk. I | ||
42 | added a Geigel Double Talk Detector (DTD) [2] and performed some | ||
43 | G168 tests. However I had trouble meeting the G168 requirements, | ||
44 | especially for double talk - there were always cases where my DTD | ||
45 | failed, for example where near end speech was under the 6dB | ||
46 | threshold required for declaring double talk. | ||
47 | |||
48 | So I tried a two path algorithm [1], which has so far given better | ||
49 | results. The original tap rotation/Geigel algorithm is available | ||
50 | in SVN http://svn.rowetel.com/software/oslec/tags/before_16bit. | ||
51 | It's probably possible to make it work if some one wants to put some | ||
52 | serious work into it. | ||
53 | |||
54 | At present no special treatment is provided for tones, which | ||
55 | generally cause NLMS algorithms to diverge. Initial runs of a | ||
56 | subset of the G168 tests for tones (e.g ./echo_test 6) show the | ||
57 | current algorithm is passing OK, which is kind of surprising. The | ||
58 | full set of tests needs to be performed to confirm this result. | ||
59 | |||
60 | One other interesting change is that I have managed to get the NLMS | ||
61 | code to work with 16 bit coefficients, rather than the original 32 | ||
62 | bit coefficents. This reduces the MIPs and storage required. | ||
63 | I evaulated the 16 bit port using g168_tests.sh and listening tests | ||
64 | on 4 real-world samples. | ||
65 | |||
66 | I also attempted the implementation of a block based NLMS update | ||
67 | [2] but although this passes g168_tests.sh it didn't converge well | ||
68 | on the real-world samples. I have no idea why, perhaps a scaling | ||
69 | problem. The block based code is also available in SVN | ||
70 | http://svn.rowetel.com/software/oslec/tags/before_16bit. If this | ||
71 | code can be debugged, it will lead to further reduction in MIPS, as | ||
72 | the block update code maps nicely onto DSP instruction sets (it's a | ||
73 | dot product) compared to the current sample-by-sample update. | ||
74 | |||
75 | Steve also has some nice notes on echo cancellers in echo.h | ||
76 | |||
77 | |||
78 | References: | ||
79 | |||
80 | [1] Ochiai, Areseki, and Ogihara, "Echo Canceller with Two Echo | ||
81 | Path Models", IEEE Transactions on communications, COM-25, | ||
82 | No. 6, June | ||
83 | 1977. | ||
84 | http://www.rowetel.com/images/echo/dual_path_paper.pdf | ||
85 | |||
86 | [2] The classic, very useful paper that tells you how to | ||
87 | actually build a real world echo canceller: | ||
88 | Messerschmitt, Hedberg, Cole, Haoui, Winship, "Digital Voice | ||
89 | Echo Canceller with a TMS320020, | ||
90 | http://www.rowetel.com/images/echo/spra129.pdf | ||
91 | |||
92 | [3] I have written a series of blog posts on this work, here is | ||
93 | Part 1: http://www.rowetel.com/blog/?p=18 | ||
94 | |||
95 | [4] The source code http://svn.rowetel.com/software/oslec/ | ||
96 | |||
97 | [5] A nice reference on LMS filters: | ||
98 | http://en.wikipedia.org/wiki/Least_mean_squares_filter | ||
99 | |||
100 | Credits: | ||
101 | |||
102 | Thanks to Steve Underwood, Jean-Marc Valin, and Ramakrishnan | ||
103 | Muthukrishnan for their suggestions and email discussions. Thanks | ||
104 | also to those people who collected echo samples for me such as | ||
105 | Mark, Pawel, and Pavel. | ||
106 | */ | ||
107 | |||
108 | #include <linux/kernel.h> /* We're doing kernel work */ | ||
109 | #include <linux/module.h> | ||
110 | #include <linux/kernel.h> | ||
111 | #include <linux/slab.h> | ||
112 | #define malloc(a) kmalloc((a), GFP_KERNEL) | ||
113 | #define free(a) kfree(a) | ||
114 | |||
115 | #include "bit_operations.h" | ||
116 | #include "echo.h" | ||
117 | |||
118 | #define MIN_TX_POWER_FOR_ADAPTION 64 | ||
119 | #define MIN_RX_POWER_FOR_ADAPTION 64 | ||
120 | #define DTD_HANGOVER 600 /* 600 samples, or 75ms */ | ||
121 | #define DC_LOG2BETA 3 /* log2() of DC filter Beta */ | ||
122 | |||
123 | /*-----------------------------------------------------------------------*\ | ||
124 | FUNCTIONS | ||
125 | \*-----------------------------------------------------------------------*/ | ||
126 | |||
127 | /* adapting coeffs using the traditional stochastic descent (N)LMS algorithm */ | ||
128 | |||
129 | |||
130 | #ifdef __BLACKFIN_ASM__ | ||
131 | static void __inline__ lms_adapt_bg(echo_can_state_t *ec, int clean, int shift) | ||
132 | { | ||
133 | int i, j; | ||
134 | int offset1; | ||
135 | int offset2; | ||
136 | int factor; | ||
137 | int exp; | ||
138 | int16_t *phist; | ||
139 | int n; | ||
140 | |||
141 | if (shift > 0) | ||
142 | factor = clean << shift; | ||
143 | else | ||
144 | factor = clean >> -shift; | ||
145 | |||
146 | /* Update the FIR taps */ | ||
147 | |||
148 | offset2 = ec->curr_pos; | ||
149 | offset1 = ec->taps - offset2; | ||
150 | phist = &ec->fir_state_bg.history[offset2]; | ||
151 | |||
152 | /* st: and en: help us locate the assembler in echo.s */ | ||
153 | |||
154 | //asm("st:"); | ||
155 | n = ec->taps; | ||
156 | for (i = 0, j = offset2; i < n; i++, j++) | ||
157 | { | ||
158 | exp = *phist++ * factor; | ||
159 | ec->fir_taps16[1][i] += (int16_t) ((exp+(1<<14)) >> 15); | ||
160 | } | ||
161 | //asm("en:"); | ||
162 | |||
163 | /* Note the asm for the inner loop above generated by Blackfin gcc | ||
164 | 4.1.1 is pretty good (note even parallel instructions used): | ||
165 | |||
166 | R0 = W [P0++] (X); | ||
167 | R0 *= R2; | ||
168 | R0 = R0 + R3 (NS) || | ||
169 | R1 = W [P1] (X) || | ||
170 | nop; | ||
171 | R0 >>>= 15; | ||
172 | R0 = R0 + R1; | ||
173 | W [P1++] = R0; | ||
174 | |||
175 | A block based update algorithm would be much faster but the | ||
176 | above can't be improved on much. Every instruction saved in | ||
177 | the loop above is 2 MIPs/ch! The for loop above is where the | ||
178 | Blackfin spends most of it's time - about 17 MIPs/ch measured | ||
179 | with speedtest.c with 256 taps (32ms). Write-back and | ||
180 | Write-through cache gave about the same performance. | ||
181 | */ | ||
182 | } | ||
183 | |||
184 | /* | ||
185 | IDEAS for further optimisation of lms_adapt_bg(): | ||
186 | |||
187 | 1/ The rounding is quite costly. Could we keep as 32 bit coeffs | ||
188 | then make filter pluck the MS 16-bits of the coeffs when filtering? | ||
189 | However this would lower potential optimisation of filter, as I | ||
190 | think the dual-MAC architecture requires packed 16 bit coeffs. | ||
191 | |||
192 | 2/ Block based update would be more efficient, as per comments above, | ||
193 | could use dual MAC architecture. | ||
194 | |||
195 | 3/ Look for same sample Blackfin LMS code, see if we can get dual-MAC | ||
196 | packing. | ||
197 | |||
198 | 4/ Execute the whole e/c in a block of say 20ms rather than sample | ||
199 | by sample. Processing a few samples every ms is inefficient. | ||
200 | */ | ||
201 | |||
202 | #else | ||
203 | static __inline__ void lms_adapt_bg(echo_can_state_t *ec, int clean, int shift) | ||
204 | { | ||
205 | int i; | ||
206 | |||
207 | int offset1; | ||
208 | int offset2; | ||
209 | int factor; | ||
210 | int exp; | ||
211 | |||
212 | if (shift > 0) | ||
213 | factor = clean << shift; | ||
214 | else | ||
215 | factor = clean >> -shift; | ||
216 | |||
217 | /* Update the FIR taps */ | ||
218 | |||
219 | offset2 = ec->curr_pos; | ||
220 | offset1 = ec->taps - offset2; | ||
221 | |||
222 | for (i = ec->taps - 1; i >= offset1; i--) | ||
223 | { | ||
224 | exp = (ec->fir_state_bg.history[i - offset1]*factor); | ||
225 | ec->fir_taps16[1][i] += (int16_t) ((exp+(1<<14)) >> 15); | ||
226 | } | ||
227 | for ( ; i >= 0; i--) | ||
228 | { | ||
229 | exp = (ec->fir_state_bg.history[i + offset2]*factor); | ||
230 | ec->fir_taps16[1][i] += (int16_t) ((exp+(1<<14)) >> 15); | ||
231 | } | ||
232 | } | ||
233 | #endif | ||
234 | |||
235 | /*- End of function --------------------------------------------------------*/ | ||
236 | |||
237 | echo_can_state_t *echo_can_create(int len, int adaption_mode) | ||
238 | { | ||
239 | echo_can_state_t *ec; | ||
240 | int i; | ||
241 | int j; | ||
242 | |||
243 | ec = kmalloc(sizeof(*ec), GFP_KERNEL); | ||
244 | if (ec == NULL) | ||
245 | return NULL; | ||
246 | memset(ec, 0, sizeof(*ec)); | ||
247 | |||
248 | ec->taps = len; | ||
249 | ec->log2taps = top_bit(len); | ||
250 | ec->curr_pos = ec->taps - 1; | ||
251 | |||
252 | for (i = 0; i < 2; i++) | ||
253 | { | ||
254 | if ((ec->fir_taps16[i] = (int16_t *) malloc((ec->taps)*sizeof(int16_t))) == NULL) | ||
255 | { | ||
256 | for (j = 0; j < i; j++) | ||
257 | kfree(ec->fir_taps16[j]); | ||
258 | kfree(ec); | ||
259 | return NULL; | ||
260 | } | ||
261 | memset(ec->fir_taps16[i], 0, (ec->taps)*sizeof(int16_t)); | ||
262 | } | ||
263 | |||
264 | fir16_create(&ec->fir_state, | ||
265 | ec->fir_taps16[0], | ||
266 | ec->taps); | ||
267 | fir16_create(&ec->fir_state_bg, | ||
268 | ec->fir_taps16[1], | ||
269 | ec->taps); | ||
270 | |||
271 | for(i=0; i<5; i++) { | ||
272 | ec->xvtx[i] = ec->yvtx[i] = ec->xvrx[i] = ec->yvrx[i] = 0; | ||
273 | } | ||
274 | |||
275 | ec->cng_level = 1000; | ||
276 | echo_can_adaption_mode(ec, adaption_mode); | ||
277 | |||
278 | ec->snapshot = (int16_t*)malloc(ec->taps*sizeof(int16_t)); | ||
279 | memset(ec->snapshot, 0, sizeof(int16_t)*ec->taps); | ||
280 | |||
281 | ec->cond_met = 0; | ||
282 | ec->Pstates = 0; | ||
283 | ec->Ltxacc = ec->Lrxacc = ec->Lcleanacc = ec->Lclean_bgacc = 0; | ||
284 | ec->Ltx = ec->Lrx = ec->Lclean = ec->Lclean_bg = 0; | ||
285 | ec->tx_1 = ec->tx_2 = ec->rx_1 = ec->rx_2 = 0; | ||
286 | ec->Lbgn = ec->Lbgn_acc = 0; | ||
287 | ec->Lbgn_upper = 200; | ||
288 | ec->Lbgn_upper_acc = ec->Lbgn_upper << 13; | ||
289 | |||
290 | return ec; | ||
291 | } | ||
292 | /*- End of function --------------------------------------------------------*/ | ||
293 | |||
294 | void echo_can_free(echo_can_state_t *ec) | ||
295 | { | ||
296 | int i; | ||
297 | |||
298 | fir16_free(&ec->fir_state); | ||
299 | fir16_free(&ec->fir_state_bg); | ||
300 | for (i = 0; i < 2; i++) | ||
301 | kfree(ec->fir_taps16[i]); | ||
302 | kfree(ec->snapshot); | ||
303 | kfree(ec); | ||
304 | } | ||
305 | /*- End of function --------------------------------------------------------*/ | ||
306 | |||
307 | void echo_can_adaption_mode(echo_can_state_t *ec, int adaption_mode) | ||
308 | { | ||
309 | ec->adaption_mode = adaption_mode; | ||
310 | } | ||
311 | /*- End of function --------------------------------------------------------*/ | ||
312 | |||
313 | void echo_can_flush(echo_can_state_t *ec) | ||
314 | { | ||
315 | int i; | ||
316 | |||
317 | ec->Ltxacc = ec->Lrxacc = ec->Lcleanacc = ec->Lclean_bgacc = 0; | ||
318 | ec->Ltx = ec->Lrx = ec->Lclean = ec->Lclean_bg = 0; | ||
319 | ec->tx_1 = ec->tx_2 = ec->rx_1 = ec->rx_2 = 0; | ||
320 | |||
321 | ec->Lbgn = ec->Lbgn_acc = 0; | ||
322 | ec->Lbgn_upper = 200; | ||
323 | ec->Lbgn_upper_acc = ec->Lbgn_upper << 13; | ||
324 | |||
325 | ec->nonupdate_dwell = 0; | ||
326 | |||
327 | fir16_flush(&ec->fir_state); | ||
328 | fir16_flush(&ec->fir_state_bg); | ||
329 | ec->fir_state.curr_pos = ec->taps - 1; | ||
330 | ec->fir_state_bg.curr_pos = ec->taps - 1; | ||
331 | for (i = 0; i < 2; i++) | ||
332 | memset(ec->fir_taps16[i], 0, ec->taps*sizeof(int16_t)); | ||
333 | |||
334 | ec->curr_pos = ec->taps - 1; | ||
335 | ec->Pstates = 0; | ||
336 | } | ||
337 | /*- End of function --------------------------------------------------------*/ | ||
338 | |||
339 | void echo_can_snapshot(echo_can_state_t *ec) { | ||
340 | memcpy(ec->snapshot, ec->fir_taps16[0], ec->taps*sizeof(int16_t)); | ||
341 | } | ||
342 | /*- End of function --------------------------------------------------------*/ | ||
343 | |||
344 | /* Dual Path Echo Canceller ------------------------------------------------*/ | ||
345 | |||
346 | int16_t echo_can_update(echo_can_state_t *ec, int16_t tx, int16_t rx) | ||
347 | { | ||
348 | int32_t echo_value; | ||
349 | int clean_bg; | ||
350 | int tmp, tmp1; | ||
351 | |||
352 | /* Input scaling was found be required to prevent problems when tx | ||
353 | starts clipping. Another possible way to handle this would be the | ||
354 | filter coefficent scaling. */ | ||
355 | |||
356 | ec->tx = tx; ec->rx = rx; | ||
357 | tx >>=1; | ||
358 | rx >>=1; | ||
359 | |||
360 | /* | ||
361 | Filter DC, 3dB point is 160Hz (I think), note 32 bit precision required | ||
362 | otherwise values do not track down to 0. Zero at DC, Pole at (1-Beta) | ||
363 | only real axis. Some chip sets (like Si labs) don't need | ||
364 | this, but something like a $10 X100P card does. Any DC really slows | ||
365 | down convergence. | ||
366 | |||
367 | Note: removes some low frequency from the signal, this reduces | ||
368 | the speech quality when listening to samples through headphones | ||
369 | but may not be obvious through a telephone handset. | ||
370 | |||
371 | Note that the 3dB frequency in radians is approx Beta, e.g. for | ||
372 | Beta = 2^(-3) = 0.125, 3dB freq is 0.125 rads = 159Hz. | ||
373 | */ | ||
374 | |||
375 | if (ec->adaption_mode & ECHO_CAN_USE_RX_HPF) { | ||
376 | tmp = rx << 15; | ||
377 | #if 1 | ||
378 | /* Make sure the gain of the HPF is 1.0. This can still saturate a little under | ||
379 | impulse conditions, and it might roll to 32768 and need clipping on sustained peak | ||
380 | level signals. However, the scale of such clipping is small, and the error due to | ||
381 | any saturation should not markedly affect the downstream processing. */ | ||
382 | tmp -= (tmp >> 4); | ||
383 | #endif | ||
384 | ec->rx_1 += -(ec->rx_1>>DC_LOG2BETA) + tmp - ec->rx_2; | ||
385 | |||
386 | /* hard limit filter to prevent clipping. Note that at this stage | ||
387 | rx should be limited to +/- 16383 due to right shift above */ | ||
388 | tmp1 = ec->rx_1 >> 15; | ||
389 | if (tmp1 > 16383) tmp1 = 16383; | ||
390 | if (tmp1 < -16383) tmp1 = -16383; | ||
391 | rx = tmp1; | ||
392 | ec->rx_2 = tmp; | ||
393 | } | ||
394 | |||
395 | /* Block average of power in the filter states. Used for | ||
396 | adaption power calculation. */ | ||
397 | |||
398 | { | ||
399 | int new, old; | ||
400 | |||
401 | /* efficient "out with the old and in with the new" algorithm so | ||
402 | we don't have to recalculate over the whole block of | ||
403 | samples. */ | ||
404 | new = (int)tx * (int)tx; | ||
405 | old = (int)ec->fir_state.history[ec->fir_state.curr_pos] * | ||
406 | (int)ec->fir_state.history[ec->fir_state.curr_pos]; | ||
407 | ec->Pstates += ((new - old) + (1<<ec->log2taps)) >> ec->log2taps; | ||
408 | if (ec->Pstates < 0) ec->Pstates = 0; | ||
409 | } | ||
410 | |||
411 | /* Calculate short term average levels using simple single pole IIRs */ | ||
412 | |||
413 | ec->Ltxacc += abs(tx) - ec->Ltx; | ||
414 | ec->Ltx = (ec->Ltxacc + (1<<4)) >> 5; | ||
415 | ec->Lrxacc += abs(rx) - ec->Lrx; | ||
416 | ec->Lrx = (ec->Lrxacc + (1<<4)) >> 5; | ||
417 | |||
418 | /* Foreground filter ---------------------------------------------------*/ | ||
419 | |||
420 | ec->fir_state.coeffs = ec->fir_taps16[0]; | ||
421 | echo_value = fir16(&ec->fir_state, tx); | ||
422 | ec->clean = rx - echo_value; | ||
423 | ec->Lcleanacc += abs(ec->clean) - ec->Lclean; | ||
424 | ec->Lclean = (ec->Lcleanacc + (1<<4)) >> 5; | ||
425 | |||
426 | /* Background filter ---------------------------------------------------*/ | ||
427 | |||
428 | echo_value = fir16(&ec->fir_state_bg, tx); | ||
429 | clean_bg = rx - echo_value; | ||
430 | ec->Lclean_bgacc += abs(clean_bg) - ec->Lclean_bg; | ||
431 | ec->Lclean_bg = (ec->Lclean_bgacc + (1<<4)) >> 5; | ||
432 | |||
433 | /* Background Filter adaption -----------------------------------------*/ | ||
434 | |||
435 | /* Almost always adap bg filter, just simple DT and energy | ||
436 | detection to minimise adaption in cases of strong double talk. | ||
437 | However this is not critical for the dual path algorithm. | ||
438 | */ | ||
439 | ec->factor = 0; | ||
440 | ec->shift = 0; | ||
441 | if ((ec->nonupdate_dwell == 0)) { | ||
442 | int P, logP, shift; | ||
443 | |||
444 | /* Determine: | ||
445 | |||
446 | f = Beta * clean_bg_rx/P ------ (1) | ||
447 | |||
448 | where P is the total power in the filter states. | ||
449 | |||
450 | The Boffins have shown that if we obey (1) we converge | ||
451 | quickly and avoid instability. | ||
452 | |||
453 | The correct factor f must be in Q30, as this is the fixed | ||
454 | point format required by the lms_adapt_bg() function, | ||
455 | therefore the scaled version of (1) is: | ||
456 | |||
457 | (2^30) * f = (2^30) * Beta * clean_bg_rx/P | ||
458 | factor = (2^30) * Beta * clean_bg_rx/P ----- (2) | ||
459 | |||
460 | We have chosen Beta = 0.25 by experiment, so: | ||
461 | |||
462 | factor = (2^30) * (2^-2) * clean_bg_rx/P | ||
463 | |||
464 | (30 - 2 - log2(P)) | ||
465 | factor = clean_bg_rx 2 ----- (3) | ||
466 | |||
467 | To avoid a divide we approximate log2(P) as top_bit(P), | ||
468 | which returns the position of the highest non-zero bit in | ||
469 | P. This approximation introduces an error as large as a | ||
470 | factor of 2, but the algorithm seems to handle it OK. | ||
471 | |||
472 | Come to think of it a divide may not be a big deal on a | ||
473 | modern DSP, so its probably worth checking out the cycles | ||
474 | for a divide versus a top_bit() implementation. | ||
475 | */ | ||
476 | |||
477 | P = MIN_TX_POWER_FOR_ADAPTION + ec->Pstates; | ||
478 | logP = top_bit(P) + ec->log2taps; | ||
479 | shift = 30 - 2 - logP; | ||
480 | ec->shift = shift; | ||
481 | |||
482 | lms_adapt_bg(ec, clean_bg, shift); | ||
483 | } | ||
484 | |||
485 | /* very simple DTD to make sure we dont try and adapt with strong | ||
486 | near end speech */ | ||
487 | |||
488 | ec->adapt = 0; | ||
489 | if ((ec->Lrx > MIN_RX_POWER_FOR_ADAPTION) && (ec->Lrx > ec->Ltx)) | ||
490 | ec->nonupdate_dwell = DTD_HANGOVER; | ||
491 | if (ec->nonupdate_dwell) | ||
492 | ec->nonupdate_dwell--; | ||
493 | |||
494 | /* Transfer logic ------------------------------------------------------*/ | ||
495 | |||
496 | /* These conditions are from the dual path paper [1], I messed with | ||
497 | them a bit to improve performance. */ | ||
498 | |||
499 | if ((ec->adaption_mode & ECHO_CAN_USE_ADAPTION) && | ||
500 | (ec->nonupdate_dwell == 0) && | ||
501 | (8*ec->Lclean_bg < 7*ec->Lclean) /* (ec->Lclean_bg < 0.875*ec->Lclean) */ && | ||
502 | (8*ec->Lclean_bg < ec->Ltx) /* (ec->Lclean_bg < 0.125*ec->Ltx) */ ) | ||
503 | { | ||
504 | if (ec->cond_met == 6) { | ||
505 | /* BG filter has had better results for 6 consecutive samples */ | ||
506 | ec->adapt = 1; | ||
507 | memcpy(ec->fir_taps16[0], ec->fir_taps16[1], ec->taps*sizeof(int16_t)); | ||
508 | } | ||
509 | else | ||
510 | ec->cond_met++; | ||
511 | } | ||
512 | else | ||
513 | ec->cond_met = 0; | ||
514 | |||
515 | /* Non-Linear Processing ---------------------------------------------------*/ | ||
516 | |||
517 | ec->clean_nlp = ec->clean; | ||
518 | if (ec->adaption_mode & ECHO_CAN_USE_NLP) | ||
519 | { | ||
520 | /* Non-linear processor - a fancy way to say "zap small signals, to avoid | ||
521 | residual echo due to (uLaw/ALaw) non-linearity in the channel.". */ | ||
522 | |||
523 | if ((16*ec->Lclean < ec->Ltx)) | ||
524 | { | ||
525 | /* Our e/c has improved echo by at least 24 dB (each factor of 2 is 6dB, | ||
526 | so 2*2*2*2=16 is the same as 6+6+6+6=24dB) */ | ||
527 | if (ec->adaption_mode & ECHO_CAN_USE_CNG) | ||
528 | { | ||
529 | ec->cng_level = ec->Lbgn; | ||
530 | |||
531 | /* Very elementary comfort noise generation. Just random | ||
532 | numbers rolled off very vaguely Hoth-like. DR: This | ||
533 | noise doesn't sound quite right to me - I suspect there | ||
534 | are some overlfow issues in the filtering as it's too | ||
535 | "crackly". TODO: debug this, maybe just play noise at | ||
536 | high level or look at spectrum. | ||
537 | */ | ||
538 | |||
539 | ec->cng_rndnum = 1664525U*ec->cng_rndnum + 1013904223U; | ||
540 | ec->cng_filter = ((ec->cng_rndnum & 0xFFFF) - 32768 + 5*ec->cng_filter) >> 3; | ||
541 | ec->clean_nlp = (ec->cng_filter*ec->cng_level*8) >> 14; | ||
542 | |||
543 | } | ||
544 | else if (ec->adaption_mode & ECHO_CAN_USE_CLIP) | ||
545 | { | ||
546 | /* This sounds much better than CNG */ | ||
547 | if (ec->clean_nlp > ec->Lbgn) | ||
548 | ec->clean_nlp = ec->Lbgn; | ||
549 | if (ec->clean_nlp < -ec->Lbgn) | ||
550 | ec->clean_nlp = -ec->Lbgn; | ||
551 | } | ||
552 | else | ||
553 | { | ||
554 | /* just mute the residual, doesn't sound very good, used mainly | ||
555 | in G168 tests */ | ||
556 | ec->clean_nlp = 0; | ||
557 | } | ||
558 | } | ||
559 | else { | ||
560 | /* Background noise estimator. I tried a few algorithms | ||
561 | here without much luck. This very simple one seems to | ||
562 | work best, we just average the level using a slow (1 sec | ||
563 | time const) filter if the current level is less than a | ||
564 | (experimentally derived) constant. This means we dont | ||
565 | include high level signals like near end speech. When | ||
566 | combined with CNG or especially CLIP seems to work OK. | ||
567 | */ | ||
568 | if (ec->Lclean < 40) { | ||
569 | ec->Lbgn_acc += abs(ec->clean) - ec->Lbgn; | ||
570 | ec->Lbgn = (ec->Lbgn_acc + (1<<11)) >> 12; | ||
571 | } | ||
572 | } | ||
573 | } | ||
574 | |||
575 | /* Roll around the taps buffer */ | ||
576 | if (ec->curr_pos <= 0) | ||
577 | ec->curr_pos = ec->taps; | ||
578 | ec->curr_pos--; | ||
579 | |||
580 | if (ec->adaption_mode & ECHO_CAN_DISABLE) | ||
581 | ec->clean_nlp = rx; | ||
582 | |||
583 | /* Output scaled back up again to match input scaling */ | ||
584 | |||
585 | return (int16_t) ec->clean_nlp << 1; | ||
586 | } | ||
587 | |||
588 | /*- End of function --------------------------------------------------------*/ | ||
589 | |||
590 | /* This function is seperated from the echo canceller is it is usually called | ||
591 | as part of the tx process. See rx HP (DC blocking) filter above, it's | ||
592 | the same design. | ||
593 | |||
594 | Some soft phones send speech signals with a lot of low frequency | ||
595 | energy, e.g. down to 20Hz. This can make the hybrid non-linear | ||
596 | which causes the echo canceller to fall over. This filter can help | ||
597 | by removing any low frequency before it gets to the tx port of the | ||
598 | hybrid. | ||
599 | |||
600 | It can also help by removing and DC in the tx signal. DC is bad | ||
601 | for LMS algorithms. | ||
602 | |||
603 | This is one of the classic DC removal filters, adjusted to provide sufficient | ||
604 | bass rolloff to meet the above requirement to protect hybrids from things that | ||
605 | upset them. The difference between successive samples produces a lousy HPF, and | ||
606 | then a suitably placed pole flattens things out. The final result is a nicely | ||
607 | rolled off bass end. The filtering is implemented with extended fractional | ||
608 | precision, which noise shapes things, giving very clean DC removal. | ||
609 | */ | ||
610 | |||
611 | int16_t echo_can_hpf_tx(echo_can_state_t *ec, int16_t tx) { | ||
612 | int tmp, tmp1; | ||
613 | |||
614 | if (ec->adaption_mode & ECHO_CAN_USE_TX_HPF) { | ||
615 | tmp = tx << 15; | ||
616 | #if 1 | ||
617 | /* Make sure the gain of the HPF is 1.0. The first can still saturate a little under | ||
618 | impulse conditions, and it might roll to 32768 and need clipping on sustained peak | ||
619 | level signals. However, the scale of such clipping is small, and the error due to | ||
620 | any saturation should not markedly affect the downstream processing. */ | ||
621 | tmp -= (tmp >> 4); | ||
622 | #endif | ||
623 | ec->tx_1 += -(ec->tx_1>>DC_LOG2BETA) + tmp - ec->tx_2; | ||
624 | tmp1 = ec->tx_1 >> 15; | ||
625 | if (tmp1 > 32767) tmp1 = 32767; | ||
626 | if (tmp1 < -32767) tmp1 = -32767; | ||
627 | tx = tmp1; | ||
628 | ec->tx_2 = tmp; | ||
629 | } | ||
630 | |||
631 | return tx; | ||
632 | } | ||
diff --git a/drivers/staging/echo/echo.h b/drivers/staging/echo/echo.h new file mode 100644 index 000000000000..7a91b4390f3b --- /dev/null +++ b/drivers/staging/echo/echo.h | |||
@@ -0,0 +1,220 @@ | |||
1 | /* | ||
2 | * SpanDSP - a series of DSP components for telephony | ||
3 | * | ||
4 | * echo.c - A line echo canceller. This code is being developed | ||
5 | * against and partially complies with G168. | ||
6 | * | ||
7 | * Written by Steve Underwood <steveu@coppice.org> | ||
8 | * and David Rowe <david_at_rowetel_dot_com> | ||
9 | * | ||
10 | * Copyright (C) 2001 Steve Underwood and 2007 David Rowe | ||
11 | * | ||
12 | * All rights reserved. | ||
13 | * | ||
14 | * This program is free software; you can redistribute it and/or modify | ||
15 | * it under the terms of the GNU General Public License version 2, as | ||
16 | * published by the Free Software Foundation. | ||
17 | * | ||
18 | * This program is distributed in the hope that it will be useful, | ||
19 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
20 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
21 | * GNU General Public License for more details. | ||
22 | * | ||
23 | * You should have received a copy of the GNU General Public License | ||
24 | * along with this program; if not, write to the Free Software | ||
25 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | ||
26 | * | ||
27 | * $Id: echo.h,v 1.9 2006/10/24 13:45:28 steveu Exp $ | ||
28 | */ | ||
29 | |||
30 | #ifndef __ECHO_H | ||
31 | #define __ECHO_H | ||
32 | |||
33 | /*! \page echo_can_page Line echo cancellation for voice | ||
34 | |||
35 | \section echo_can_page_sec_1 What does it do? | ||
36 | This module aims to provide G.168-2002 compliant echo cancellation, to remove | ||
37 | electrical echoes (e.g. from 2-4 wire hybrids) from voice calls. | ||
38 | |||
39 | \section echo_can_page_sec_2 How does it work? | ||
40 | The heart of the echo cancellor is FIR filter. This is adapted to match the | ||
41 | echo impulse response of the telephone line. It must be long enough to | ||
42 | adequately cover the duration of that impulse response. The signal transmitted | ||
43 | to the telephone line is passed through the FIR filter. Once the FIR is | ||
44 | properly adapted, the resulting output is an estimate of the echo signal | ||
45 | received from the line. This is subtracted from the received signal. The result | ||
46 | is an estimate of the signal which originated at the far end of the line, free | ||
47 | from echos of our own transmitted signal. | ||
48 | |||
49 | The least mean squares (LMS) algorithm is attributed to Widrow and Hoff, and | ||
50 | was introduced in 1960. It is the commonest form of filter adaption used in | ||
51 | things like modem line equalisers and line echo cancellers. There it works very | ||
52 | well. However, it only works well for signals of constant amplitude. It works | ||
53 | very poorly for things like speech echo cancellation, where the signal level | ||
54 | varies widely. This is quite easy to fix. If the signal level is normalised - | ||
55 | similar to applying AGC - LMS can work as well for a signal of varying | ||
56 | amplitude as it does for a modem signal. This normalised least mean squares | ||
57 | (NLMS) algorithm is the commonest one used for speech echo cancellation. Many | ||
58 | other algorithms exist - e.g. RLS (essentially the same as Kalman filtering), | ||
59 | FAP, etc. Some perform significantly better than NLMS. However, factors such | ||
60 | as computational complexity and patents favour the use of NLMS. | ||
61 | |||
62 | A simple refinement to NLMS can improve its performance with speech. NLMS tends | ||
63 | to adapt best to the strongest parts of a signal. If the signal is white noise, | ||
64 | the NLMS algorithm works very well. However, speech has more low frequency than | ||
65 | high frequency content. Pre-whitening (i.e. filtering the signal to flatten its | ||
66 | spectrum) the echo signal improves the adapt rate for speech, and ensures the | ||
67 | final residual signal is not heavily biased towards high frequencies. A very | ||
68 | low complexity filter is adequate for this, so pre-whitening adds little to the | ||
69 | compute requirements of the echo canceller. | ||
70 | |||
71 | An FIR filter adapted using pre-whitened NLMS performs well, provided certain | ||
72 | conditions are met: | ||
73 | |||
74 | - The transmitted signal has poor self-correlation. | ||
75 | - There is no signal being generated within the environment being | ||
76 | cancelled. | ||
77 | |||
78 | The difficulty is that neither of these can be guaranteed. | ||
79 | |||
80 | If the adaption is performed while transmitting noise (or something fairly | ||
81 | noise like, such as voice) the adaption works very well. If the adaption is | ||
82 | performed while transmitting something highly correlative (typically narrow | ||
83 | band energy such as signalling tones or DTMF), the adaption can go seriously | ||
84 | wrong. The reason is there is only one solution for the adaption on a near | ||
85 | random signal - the impulse response of the line. For a repetitive signal, | ||
86 | there are any number of solutions which converge the adaption, and nothing | ||
87 | guides the adaption to choose the generalised one. Allowing an untrained | ||
88 | canceller to converge on this kind of narrowband energy probably a good thing, | ||
89 | since at least it cancels the tones. Allowing a well converged canceller to | ||
90 | continue converging on such energy is just a way to ruin its generalised | ||
91 | adaption. A narrowband detector is needed, so adapation can be suspended at | ||
92 | appropriate times. | ||
93 | |||
94 | The adaption process is based on trying to eliminate the received signal. When | ||
95 | there is any signal from within the environment being cancelled it may upset | ||
96 | the adaption process. Similarly, if the signal we are transmitting is small, | ||
97 | noise may dominate and disturb the adaption process. If we can ensure that the | ||
98 | adaption is only performed when we are transmitting a significant signal level, | ||
99 | and the environment is not, things will be OK. Clearly, it is easy to tell when | ||
100 | we are sending a significant signal. Telling, if the environment is generating | ||
101 | a significant signal, and doing it with sufficient speed that the adaption will | ||
102 | not have diverged too much more we stop it, is a little harder. | ||
103 | |||
104 | The key problem in detecting when the environment is sourcing significant | ||
105 | energy is that we must do this very quickly. Given a reasonably long sample of | ||
106 | the received signal, there are a number of strategies which may be used to | ||
107 | assess whether that signal contains a strong far end component. However, by the | ||
108 | time that assessment is complete the far end signal will have already caused | ||
109 | major mis-convergence in the adaption process. An assessment algorithm is | ||
110 | needed which produces a fairly accurate result from a very short burst of far | ||
111 | end energy. | ||
112 | |||
113 | \section echo_can_page_sec_3 How do I use it? | ||
114 | The echo cancellor processes both the transmit and receive streams sample by | ||
115 | sample. The processing function is not declared inline. Unfortunately, | ||
116 | cancellation requires many operations per sample, so the call overhead is only | ||
117 | a minor burden. | ||
118 | */ | ||
119 | |||
120 | #include "fir.h" | ||
121 | |||
122 | /* Mask bits for the adaption mode */ | ||
123 | #define ECHO_CAN_USE_ADAPTION 0x01 | ||
124 | #define ECHO_CAN_USE_NLP 0x02 | ||
125 | #define ECHO_CAN_USE_CNG 0x04 | ||
126 | #define ECHO_CAN_USE_CLIP 0x08 | ||
127 | #define ECHO_CAN_USE_TX_HPF 0x10 | ||
128 | #define ECHO_CAN_USE_RX_HPF 0x20 | ||
129 | #define ECHO_CAN_DISABLE 0x40 | ||
130 | |||
131 | /*! | ||
132 | G.168 echo canceller descriptor. This defines the working state for a line | ||
133 | echo canceller. | ||
134 | */ | ||
135 | typedef struct | ||
136 | { | ||
137 | int16_t tx,rx; | ||
138 | int16_t clean; | ||
139 | int16_t clean_nlp; | ||
140 | |||
141 | int nonupdate_dwell; | ||
142 | int curr_pos; | ||
143 | int taps; | ||
144 | int log2taps; | ||
145 | int adaption_mode; | ||
146 | |||
147 | int cond_met; | ||
148 | int32_t Pstates; | ||
149 | int16_t adapt; | ||
150 | int32_t factor; | ||
151 | int16_t shift; | ||
152 | |||
153 | /* Average levels and averaging filter states */ | ||
154 | int Ltxacc, Lrxacc, Lcleanacc, Lclean_bgacc; | ||
155 | int Ltx, Lrx; | ||
156 | int Lclean; | ||
157 | int Lclean_bg; | ||
158 | int Lbgn, Lbgn_acc, Lbgn_upper, Lbgn_upper_acc; | ||
159 | |||
160 | /* foreground and background filter states */ | ||
161 | fir16_state_t fir_state; | ||
162 | fir16_state_t fir_state_bg; | ||
163 | int16_t *fir_taps16[2]; | ||
164 | |||
165 | /* DC blocking filter states */ | ||
166 | int tx_1, tx_2, rx_1, rx_2; | ||
167 | |||
168 | /* optional High Pass Filter states */ | ||
169 | int32_t xvtx[5], yvtx[5]; | ||
170 | int32_t xvrx[5], yvrx[5]; | ||
171 | |||
172 | /* Parameters for the optional Hoth noise generator */ | ||
173 | int cng_level; | ||
174 | int cng_rndnum; | ||
175 | int cng_filter; | ||
176 | |||
177 | /* snapshot sample of coeffs used for development */ | ||
178 | int16_t *snapshot; | ||
179 | } echo_can_state_t; | ||
180 | |||
181 | /*! Create a voice echo canceller context. | ||
182 | \param len The length of the canceller, in samples. | ||
183 | \return The new canceller context, or NULL if the canceller could not be created. | ||
184 | */ | ||
185 | echo_can_state_t *echo_can_create(int len, int adaption_mode); | ||
186 | |||
187 | /*! Free a voice echo canceller context. | ||
188 | \param ec The echo canceller context. | ||
189 | */ | ||
190 | void echo_can_free(echo_can_state_t *ec); | ||
191 | |||
192 | /*! Flush (reinitialise) a voice echo canceller context. | ||
193 | \param ec The echo canceller context. | ||
194 | */ | ||
195 | void echo_can_flush(echo_can_state_t *ec); | ||
196 | |||
197 | /*! Set the adaption mode of a voice echo canceller context. | ||
198 | \param ec The echo canceller context. | ||
199 | \param adapt The mode. | ||
200 | */ | ||
201 | void echo_can_adaption_mode(echo_can_state_t *ec, int adaption_mode); | ||
202 | |||
203 | void echo_can_snapshot(echo_can_state_t *ec); | ||
204 | |||
205 | /*! Process a sample through a voice echo canceller. | ||
206 | \param ec The echo canceller context. | ||
207 | \param tx The transmitted audio sample. | ||
208 | \param rx The received audio sample. | ||
209 | \return The clean (echo cancelled) received sample. | ||
210 | */ | ||
211 | int16_t echo_can_update(echo_can_state_t *ec, int16_t tx, int16_t rx); | ||
212 | |||
213 | /*! Process to high pass filter the tx signal. | ||
214 | \param ec The echo canceller context. | ||
215 | \param tx The transmitted auio sample. | ||
216 | \return The HP filtered transmit sample, send this to your D/A. | ||
217 | */ | ||
218 | int16_t echo_can_hpf_tx(echo_can_state_t *ec, int16_t tx); | ||
219 | |||
220 | #endif /* __ECHO_H */ | ||
diff --git a/drivers/staging/echo/fir.h b/drivers/staging/echo/fir.h new file mode 100644 index 000000000000..e1bfc4994886 --- /dev/null +++ b/drivers/staging/echo/fir.h | |||
@@ -0,0 +1,369 @@ | |||
1 | /* | ||
2 | * SpanDSP - a series of DSP components for telephony | ||
3 | * | ||
4 | * fir.h - General telephony FIR routines | ||
5 | * | ||
6 | * Written by Steve Underwood <steveu@coppice.org> | ||
7 | * | ||
8 | * Copyright (C) 2002 Steve Underwood | ||
9 | * | ||
10 | * All rights reserved. | ||
11 | * | ||
12 | * This program is free software; you can redistribute it and/or modify | ||
13 | * it under the terms of the GNU General Public License version 2, as | ||
14 | * published by the Free Software Foundation. | ||
15 | * | ||
16 | * This program is distributed in the hope that it will be useful, | ||
17 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
18 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
19 | * GNU General Public License for more details. | ||
20 | * | ||
21 | * You should have received a copy of the GNU General Public License | ||
22 | * along with this program; if not, write to the Free Software | ||
23 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | ||
24 | * | ||
25 | * $Id: fir.h,v 1.8 2006/10/24 13:45:28 steveu Exp $ | ||
26 | */ | ||
27 | |||
28 | /*! \page fir_page FIR filtering | ||
29 | \section fir_page_sec_1 What does it do? | ||
30 | ???. | ||
31 | |||
32 | \section fir_page_sec_2 How does it work? | ||
33 | ???. | ||
34 | */ | ||
35 | |||
36 | #if !defined(_FIR_H_) | ||
37 | #define _FIR_H_ | ||
38 | |||
39 | /* | ||
40 | Blackfin NOTES & IDEAS: | ||
41 | |||
42 | A simple dot product function is used to implement the filter. This performs | ||
43 | just one MAC/cycle which is inefficient but was easy to implement as a first | ||
44 | pass. The current Blackfin code also uses an unrolled form of the filter | ||
45 | history to avoid 0 length hardware loop issues. This is wasteful of | ||
46 | memory. | ||
47 | |||
48 | Ideas for improvement: | ||
49 | |||
50 | 1/ Rewrite filter for dual MAC inner loop. The issue here is handling | ||
51 | history sample offsets that are 16 bit aligned - the dual MAC needs | ||
52 | 32 bit aligmnent. There are some good examples in libbfdsp. | ||
53 | |||
54 | 2/ Use the hardware circular buffer facility tohalve memory usage. | ||
55 | |||
56 | 3/ Consider using internal memory. | ||
57 | |||
58 | Using less memory might also improve speed as cache misses will be | ||
59 | reduced. A drop in MIPs and memory approaching 50% should be | ||
60 | possible. | ||
61 | |||
62 | The foreground and background filters currenlty use a total of | ||
63 | about 10 MIPs/ch as measured with speedtest.c on a 256 TAP echo | ||
64 | can. | ||
65 | */ | ||
66 | |||
67 | #if defined(USE_MMX) || defined(USE_SSE2) | ||
68 | #include "mmx.h" | ||
69 | #endif | ||
70 | |||
71 | /*! | ||
72 | 16 bit integer FIR descriptor. This defines the working state for a single | ||
73 | instance of an FIR filter using 16 bit integer coefficients. | ||
74 | */ | ||
75 | typedef struct | ||
76 | { | ||
77 | int taps; | ||
78 | int curr_pos; | ||
79 | const int16_t *coeffs; | ||
80 | int16_t *history; | ||
81 | } fir16_state_t; | ||
82 | |||
83 | /*! | ||
84 | 32 bit integer FIR descriptor. This defines the working state for a single | ||
85 | instance of an FIR filter using 32 bit integer coefficients, and filtering | ||
86 | 16 bit integer data. | ||
87 | */ | ||
88 | typedef struct | ||
89 | { | ||
90 | int taps; | ||
91 | int curr_pos; | ||
92 | const int32_t *coeffs; | ||
93 | int16_t *history; | ||
94 | } fir32_state_t; | ||
95 | |||
96 | /*! | ||
97 | Floating point FIR descriptor. This defines the working state for a single | ||
98 | instance of an FIR filter using floating point coefficients and data. | ||
99 | */ | ||
100 | typedef struct | ||
101 | { | ||
102 | int taps; | ||
103 | int curr_pos; | ||
104 | const float *coeffs; | ||
105 | float *history; | ||
106 | } fir_float_state_t; | ||
107 | |||
108 | #ifdef __cplusplus | ||
109 | extern "C" { | ||
110 | #endif | ||
111 | |||
112 | static __inline__ const int16_t *fir16_create(fir16_state_t *fir, | ||
113 | const int16_t *coeffs, | ||
114 | int taps) | ||
115 | { | ||
116 | fir->taps = taps; | ||
117 | fir->curr_pos = taps - 1; | ||
118 | fir->coeffs = coeffs; | ||
119 | #if defined(USE_MMX) || defined(USE_SSE2) || defined(__BLACKFIN_ASM__) | ||
120 | if ((fir->history = malloc(2*taps*sizeof(int16_t)))) | ||
121 | memset(fir->history, 0, 2*taps*sizeof(int16_t)); | ||
122 | #else | ||
123 | if ((fir->history = (int16_t *) malloc(taps*sizeof(int16_t)))) | ||
124 | memset(fir->history, 0, taps*sizeof(int16_t)); | ||
125 | #endif | ||
126 | return fir->history; | ||
127 | } | ||
128 | /*- End of function --------------------------------------------------------*/ | ||
129 | |||
130 | static __inline__ void fir16_flush(fir16_state_t *fir) | ||
131 | { | ||
132 | #if defined(USE_MMX) || defined(USE_SSE2) || defined(__BLACKFIN_ASM__) | ||
133 | memset(fir->history, 0, 2*fir->taps*sizeof(int16_t)); | ||
134 | #else | ||
135 | memset(fir->history, 0, fir->taps*sizeof(int16_t)); | ||
136 | #endif | ||
137 | } | ||
138 | /*- End of function --------------------------------------------------------*/ | ||
139 | |||
140 | static __inline__ void fir16_free(fir16_state_t *fir) | ||
141 | { | ||
142 | free(fir->history); | ||
143 | } | ||
144 | /*- End of function --------------------------------------------------------*/ | ||
145 | |||
146 | #ifdef __BLACKFIN_ASM__ | ||
147 | static inline int32_t dot_asm(short *x, short *y, int len) | ||
148 | { | ||
149 | int dot; | ||
150 | |||
151 | len--; | ||
152 | |||
153 | __asm__ | ||
154 | ( | ||
155 | "I0 = %1;\n\t" | ||
156 | "I1 = %2;\n\t" | ||
157 | "A0 = 0;\n\t" | ||
158 | "R0.L = W[I0++] || R1.L = W[I1++];\n\t" | ||
159 | "LOOP dot%= LC0 = %3;\n\t" | ||
160 | "LOOP_BEGIN dot%=;\n\t" | ||
161 | "A0 += R0.L * R1.L (IS) || R0.L = W[I0++] || R1.L = W[I1++];\n\t" | ||
162 | "LOOP_END dot%=;\n\t" | ||
163 | "A0 += R0.L*R1.L (IS);\n\t" | ||
164 | "R0 = A0;\n\t" | ||
165 | "%0 = R0;\n\t" | ||
166 | : "=&d" (dot) | ||
167 | : "a" (x), "a" (y), "a" (len) | ||
168 | : "I0", "I1", "A1", "A0", "R0", "R1" | ||
169 | ); | ||
170 | |||
171 | return dot; | ||
172 | } | ||
173 | #endif | ||
174 | /*- End of function --------------------------------------------------------*/ | ||
175 | |||
176 | static __inline__ int16_t fir16(fir16_state_t *fir, int16_t sample) | ||
177 | { | ||
178 | int32_t y; | ||
179 | #if defined(USE_MMX) | ||
180 | int i; | ||
181 | mmx_t *mmx_coeffs; | ||
182 | mmx_t *mmx_hist; | ||
183 | |||
184 | fir->history[fir->curr_pos] = sample; | ||
185 | fir->history[fir->curr_pos + fir->taps] = sample; | ||
186 | |||
187 | mmx_coeffs = (mmx_t *) fir->coeffs; | ||
188 | mmx_hist = (mmx_t *) &fir->history[fir->curr_pos]; | ||
189 | i = fir->taps; | ||
190 | pxor_r2r(mm4, mm4); | ||
191 | /* 8 samples per iteration, so the filter must be a multiple of 8 long. */ | ||
192 | while (i > 0) | ||
193 | { | ||
194 | movq_m2r(mmx_coeffs[0], mm0); | ||
195 | movq_m2r(mmx_coeffs[1], mm2); | ||
196 | movq_m2r(mmx_hist[0], mm1); | ||
197 | movq_m2r(mmx_hist[1], mm3); | ||
198 | mmx_coeffs += 2; | ||
199 | mmx_hist += 2; | ||
200 | pmaddwd_r2r(mm1, mm0); | ||
201 | pmaddwd_r2r(mm3, mm2); | ||
202 | paddd_r2r(mm0, mm4); | ||
203 | paddd_r2r(mm2, mm4); | ||
204 | i -= 8; | ||
205 | } | ||
206 | movq_r2r(mm4, mm0); | ||
207 | psrlq_i2r(32, mm0); | ||
208 | paddd_r2r(mm0, mm4); | ||
209 | movd_r2m(mm4, y); | ||
210 | emms(); | ||
211 | #elif defined(USE_SSE2) | ||
212 | int i; | ||
213 | xmm_t *xmm_coeffs; | ||
214 | xmm_t *xmm_hist; | ||
215 | |||
216 | fir->history[fir->curr_pos] = sample; | ||
217 | fir->history[fir->curr_pos + fir->taps] = sample; | ||
218 | |||
219 | xmm_coeffs = (xmm_t *) fir->coeffs; | ||
220 | xmm_hist = (xmm_t *) &fir->history[fir->curr_pos]; | ||
221 | i = fir->taps; | ||
222 | pxor_r2r(xmm4, xmm4); | ||
223 | /* 16 samples per iteration, so the filter must be a multiple of 16 long. */ | ||
224 | while (i > 0) | ||
225 | { | ||
226 | movdqu_m2r(xmm_coeffs[0], xmm0); | ||
227 | movdqu_m2r(xmm_coeffs[1], xmm2); | ||
228 | movdqu_m2r(xmm_hist[0], xmm1); | ||
229 | movdqu_m2r(xmm_hist[1], xmm3); | ||
230 | xmm_coeffs += 2; | ||
231 | xmm_hist += 2; | ||
232 | pmaddwd_r2r(xmm1, xmm0); | ||
233 | pmaddwd_r2r(xmm3, xmm2); | ||
234 | paddd_r2r(xmm0, xmm4); | ||
235 | paddd_r2r(xmm2, xmm4); | ||
236 | i -= 16; | ||
237 | } | ||
238 | movdqa_r2r(xmm4, xmm0); | ||
239 | psrldq_i2r(8, xmm0); | ||
240 | paddd_r2r(xmm0, xmm4); | ||
241 | movdqa_r2r(xmm4, xmm0); | ||
242 | psrldq_i2r(4, xmm0); | ||
243 | paddd_r2r(xmm0, xmm4); | ||
244 | movd_r2m(xmm4, y); | ||
245 | #elif defined(__BLACKFIN_ASM__) | ||
246 | fir->history[fir->curr_pos] = sample; | ||
247 | fir->history[fir->curr_pos + fir->taps] = sample; | ||
248 | y = dot_asm((int16_t*)fir->coeffs, &fir->history[fir->curr_pos], fir->taps); | ||
249 | #else | ||
250 | int i; | ||
251 | int offset1; | ||
252 | int offset2; | ||
253 | |||
254 | fir->history[fir->curr_pos] = sample; | ||
255 | |||
256 | offset2 = fir->curr_pos; | ||
257 | offset1 = fir->taps - offset2; | ||
258 | y = 0; | ||
259 | for (i = fir->taps - 1; i >= offset1; i--) | ||
260 | y += fir->coeffs[i]*fir->history[i - offset1]; | ||
261 | for ( ; i >= 0; i--) | ||
262 | y += fir->coeffs[i]*fir->history[i + offset2]; | ||
263 | #endif | ||
264 | if (fir->curr_pos <= 0) | ||
265 | fir->curr_pos = fir->taps; | ||
266 | fir->curr_pos--; | ||
267 | return (int16_t) (y >> 15); | ||
268 | } | ||
269 | /*- End of function --------------------------------------------------------*/ | ||
270 | |||
271 | static __inline__ const int16_t *fir32_create(fir32_state_t *fir, | ||
272 | const int32_t *coeffs, | ||
273 | int taps) | ||
274 | { | ||
275 | fir->taps = taps; | ||
276 | fir->curr_pos = taps - 1; | ||
277 | fir->coeffs = coeffs; | ||
278 | fir->history = (int16_t *) malloc(taps*sizeof(int16_t)); | ||
279 | if (fir->history) | ||
280 | memset(fir->history, '\0', taps*sizeof(int16_t)); | ||
281 | return fir->history; | ||
282 | } | ||
283 | /*- End of function --------------------------------------------------------*/ | ||
284 | |||
285 | static __inline__ void fir32_flush(fir32_state_t *fir) | ||
286 | { | ||
287 | memset(fir->history, 0, fir->taps*sizeof(int16_t)); | ||
288 | } | ||
289 | /*- End of function --------------------------------------------------------*/ | ||
290 | |||
291 | static __inline__ void fir32_free(fir32_state_t *fir) | ||
292 | { | ||
293 | free(fir->history); | ||
294 | } | ||
295 | /*- End of function --------------------------------------------------------*/ | ||
296 | |||
297 | static __inline__ int16_t fir32(fir32_state_t *fir, int16_t sample) | ||
298 | { | ||
299 | int i; | ||
300 | int32_t y; | ||
301 | int offset1; | ||
302 | int offset2; | ||
303 | |||
304 | fir->history[fir->curr_pos] = sample; | ||
305 | offset2 = fir->curr_pos; | ||
306 | offset1 = fir->taps - offset2; | ||
307 | y = 0; | ||
308 | for (i = fir->taps - 1; i >= offset1; i--) | ||
309 | y += fir->coeffs[i]*fir->history[i - offset1]; | ||
310 | for ( ; i >= 0; i--) | ||
311 | y += fir->coeffs[i]*fir->history[i + offset2]; | ||
312 | if (fir->curr_pos <= 0) | ||
313 | fir->curr_pos = fir->taps; | ||
314 | fir->curr_pos--; | ||
315 | return (int16_t) (y >> 15); | ||
316 | } | ||
317 | /*- End of function --------------------------------------------------------*/ | ||
318 | |||
319 | #ifndef __KERNEL__ | ||
320 | static __inline__ const float *fir_float_create(fir_float_state_t *fir, | ||
321 | const float *coeffs, | ||
322 | int taps) | ||
323 | { | ||
324 | fir->taps = taps; | ||
325 | fir->curr_pos = taps - 1; | ||
326 | fir->coeffs = coeffs; | ||
327 | fir->history = (float *) malloc(taps*sizeof(float)); | ||
328 | if (fir->history) | ||
329 | memset(fir->history, '\0', taps*sizeof(float)); | ||
330 | return fir->history; | ||
331 | } | ||
332 | /*- End of function --------------------------------------------------------*/ | ||
333 | |||
334 | static __inline__ void fir_float_free(fir_float_state_t *fir) | ||
335 | { | ||
336 | free(fir->history); | ||
337 | } | ||
338 | /*- End of function --------------------------------------------------------*/ | ||
339 | |||
340 | static __inline__ int16_t fir_float(fir_float_state_t *fir, int16_t sample) | ||
341 | { | ||
342 | int i; | ||
343 | float y; | ||
344 | int offset1; | ||
345 | int offset2; | ||
346 | |||
347 | fir->history[fir->curr_pos] = sample; | ||
348 | |||
349 | offset2 = fir->curr_pos; | ||
350 | offset1 = fir->taps - offset2; | ||
351 | y = 0; | ||
352 | for (i = fir->taps - 1; i >= offset1; i--) | ||
353 | y += fir->coeffs[i]*fir->history[i - offset1]; | ||
354 | for ( ; i >= 0; i--) | ||
355 | y += fir->coeffs[i]*fir->history[i + offset2]; | ||
356 | if (fir->curr_pos <= 0) | ||
357 | fir->curr_pos = fir->taps; | ||
358 | fir->curr_pos--; | ||
359 | return (int16_t) y; | ||
360 | } | ||
361 | /*- End of function --------------------------------------------------------*/ | ||
362 | #endif | ||
363 | |||
364 | #ifdef __cplusplus | ||
365 | } | ||
366 | #endif | ||
367 | |||
368 | #endif | ||
369 | /*- End of file ------------------------------------------------------------*/ | ||
diff --git a/drivers/staging/echo/mmx.h b/drivers/staging/echo/mmx.h new file mode 100644 index 000000000000..b5a3964865b6 --- /dev/null +++ b/drivers/staging/echo/mmx.h | |||
@@ -0,0 +1,288 @@ | |||
1 | /* | ||
2 | * mmx.h | ||
3 | * Copyright (C) 1997-2001 H. Dietz and R. Fisher | ||
4 | * | ||
5 | * This file is part of FFmpeg. | ||
6 | * | ||
7 | * FFmpeg is free software; you can redistribute it and/or | ||
8 | * modify it under the terms of the GNU Lesser General Public | ||
9 | * License as published by the Free Software Foundation; either | ||
10 | * version 2.1 of the License, or (at your option) any later version. | ||
11 | * | ||
12 | * FFmpeg is distributed in the hope that it will be useful, | ||
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | ||
15 | * Lesser General Public License for more details. | ||
16 | * | ||
17 | * You should have received a copy of the GNU Lesser General Public | ||
18 | * License along with FFmpeg; if not, write to the Free Software | ||
19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | ||
20 | */ | ||
21 | #ifndef AVCODEC_I386MMX_H | ||
22 | #define AVCODEC_I386MMX_H | ||
23 | |||
24 | /* | ||
25 | * The type of an value that fits in an MMX register (note that long | ||
26 | * long constant values MUST be suffixed by LL and unsigned long long | ||
27 | * values by ULL, lest they be truncated by the compiler) | ||
28 | */ | ||
29 | |||
30 | typedef union { | ||
31 | long long q; /* Quadword (64-bit) value */ | ||
32 | unsigned long long uq; /* Unsigned Quadword */ | ||
33 | int d[2]; /* 2 Doubleword (32-bit) values */ | ||
34 | unsigned int ud[2]; /* 2 Unsigned Doubleword */ | ||
35 | short w[4]; /* 4 Word (16-bit) values */ | ||
36 | unsigned short uw[4]; /* 4 Unsigned Word */ | ||
37 | char b[8]; /* 8 Byte (8-bit) values */ | ||
38 | unsigned char ub[8]; /* 8 Unsigned Byte */ | ||
39 | float s[2]; /* Single-precision (32-bit) value */ | ||
40 | } mmx_t; /* On an 8-byte (64-bit) boundary */ | ||
41 | |||
42 | /* SSE registers */ | ||
43 | typedef union { | ||
44 | char b[16]; | ||
45 | } xmm_t; | ||
46 | |||
47 | |||
48 | #define mmx_i2r(op,imm,reg) \ | ||
49 | __asm__ __volatile__ (#op " %0, %%" #reg \ | ||
50 | : /* nothing */ \ | ||
51 | : "i" (imm) ) | ||
52 | |||
53 | #define mmx_m2r(op,mem,reg) \ | ||
54 | __asm__ __volatile__ (#op " %0, %%" #reg \ | ||
55 | : /* nothing */ \ | ||
56 | : "m" (mem)) | ||
57 | |||
58 | #define mmx_r2m(op,reg,mem) \ | ||
59 | __asm__ __volatile__ (#op " %%" #reg ", %0" \ | ||
60 | : "=m" (mem) \ | ||
61 | : /* nothing */ ) | ||
62 | |||
63 | #define mmx_r2r(op,regs,regd) \ | ||
64 | __asm__ __volatile__ (#op " %" #regs ", %" #regd) | ||
65 | |||
66 | |||
67 | #define emms() __asm__ __volatile__ ("emms") | ||
68 | |||
69 | #define movd_m2r(var,reg) mmx_m2r (movd, var, reg) | ||
70 | #define movd_r2m(reg,var) mmx_r2m (movd, reg, var) | ||
71 | #define movd_r2r(regs,regd) mmx_r2r (movd, regs, regd) | ||
72 | |||
73 | #define movq_m2r(var,reg) mmx_m2r (movq, var, reg) | ||
74 | #define movq_r2m(reg,var) mmx_r2m (movq, reg, var) | ||
75 | #define movq_r2r(regs,regd) mmx_r2r (movq, regs, regd) | ||
76 | |||
77 | #define packssdw_m2r(var,reg) mmx_m2r (packssdw, var, reg) | ||
78 | #define packssdw_r2r(regs,regd) mmx_r2r (packssdw, regs, regd) | ||
79 | #define packsswb_m2r(var,reg) mmx_m2r (packsswb, var, reg) | ||
80 | #define packsswb_r2r(regs,regd) mmx_r2r (packsswb, regs, regd) | ||
81 | |||
82 | #define packuswb_m2r(var,reg) mmx_m2r (packuswb, var, reg) | ||
83 | #define packuswb_r2r(regs,regd) mmx_r2r (packuswb, regs, regd) | ||
84 | |||
85 | #define paddb_m2r(var,reg) mmx_m2r (paddb, var, reg) | ||
86 | #define paddb_r2r(regs,regd) mmx_r2r (paddb, regs, regd) | ||
87 | #define paddd_m2r(var,reg) mmx_m2r (paddd, var, reg) | ||
88 | #define paddd_r2r(regs,regd) mmx_r2r (paddd, regs, regd) | ||
89 | #define paddw_m2r(var,reg) mmx_m2r (paddw, var, reg) | ||
90 | #define paddw_r2r(regs,regd) mmx_r2r (paddw, regs, regd) | ||
91 | |||
92 | #define paddsb_m2r(var,reg) mmx_m2r (paddsb, var, reg) | ||
93 | #define paddsb_r2r(regs,regd) mmx_r2r (paddsb, regs, regd) | ||
94 | #define paddsw_m2r(var,reg) mmx_m2r (paddsw, var, reg) | ||
95 | #define paddsw_r2r(regs,regd) mmx_r2r (paddsw, regs, regd) | ||
96 | |||
97 | #define paddusb_m2r(var,reg) mmx_m2r (paddusb, var, reg) | ||
98 | #define paddusb_r2r(regs,regd) mmx_r2r (paddusb, regs, regd) | ||
99 | #define paddusw_m2r(var,reg) mmx_m2r (paddusw, var, reg) | ||
100 | #define paddusw_r2r(regs,regd) mmx_r2r (paddusw, regs, regd) | ||
101 | |||
102 | #define pand_m2r(var,reg) mmx_m2r (pand, var, reg) | ||
103 | #define pand_r2r(regs,regd) mmx_r2r (pand, regs, regd) | ||
104 | |||
105 | #define pandn_m2r(var,reg) mmx_m2r (pandn, var, reg) | ||
106 | #define pandn_r2r(regs,regd) mmx_r2r (pandn, regs, regd) | ||
107 | |||
108 | #define pcmpeqb_m2r(var,reg) mmx_m2r (pcmpeqb, var, reg) | ||
109 | #define pcmpeqb_r2r(regs,regd) mmx_r2r (pcmpeqb, regs, regd) | ||
110 | #define pcmpeqd_m2r(var,reg) mmx_m2r (pcmpeqd, var, reg) | ||
111 | #define pcmpeqd_r2r(regs,regd) mmx_r2r (pcmpeqd, regs, regd) | ||
112 | #define pcmpeqw_m2r(var,reg) mmx_m2r (pcmpeqw, var, reg) | ||
113 | #define pcmpeqw_r2r(regs,regd) mmx_r2r (pcmpeqw, regs, regd) | ||
114 | |||
115 | #define pcmpgtb_m2r(var,reg) mmx_m2r (pcmpgtb, var, reg) | ||
116 | #define pcmpgtb_r2r(regs,regd) mmx_r2r (pcmpgtb, regs, regd) | ||
117 | #define pcmpgtd_m2r(var,reg) mmx_m2r (pcmpgtd, var, reg) | ||
118 | #define pcmpgtd_r2r(regs,regd) mmx_r2r (pcmpgtd, regs, regd) | ||
119 | #define pcmpgtw_m2r(var,reg) mmx_m2r (pcmpgtw, var, reg) | ||
120 | #define pcmpgtw_r2r(regs,regd) mmx_r2r (pcmpgtw, regs, regd) | ||
121 | |||
122 | #define pmaddwd_m2r(var,reg) mmx_m2r (pmaddwd, var, reg) | ||
123 | #define pmaddwd_r2r(regs,regd) mmx_r2r (pmaddwd, regs, regd) | ||
124 | |||
125 | #define pmulhw_m2r(var,reg) mmx_m2r (pmulhw, var, reg) | ||
126 | #define pmulhw_r2r(regs,regd) mmx_r2r (pmulhw, regs, regd) | ||
127 | |||
128 | #define pmullw_m2r(var,reg) mmx_m2r (pmullw, var, reg) | ||
129 | #define pmullw_r2r(regs,regd) mmx_r2r (pmullw, regs, regd) | ||
130 | |||
131 | #define por_m2r(var,reg) mmx_m2r (por, var, reg) | ||
132 | #define por_r2r(regs,regd) mmx_r2r (por, regs, regd) | ||
133 | |||
134 | #define pslld_i2r(imm,reg) mmx_i2r (pslld, imm, reg) | ||
135 | #define pslld_m2r(var,reg) mmx_m2r (pslld, var, reg) | ||
136 | #define pslld_r2r(regs,regd) mmx_r2r (pslld, regs, regd) | ||
137 | #define psllq_i2r(imm,reg) mmx_i2r (psllq, imm, reg) | ||
138 | #define psllq_m2r(var,reg) mmx_m2r (psllq, var, reg) | ||
139 | #define psllq_r2r(regs,regd) mmx_r2r (psllq, regs, regd) | ||
140 | #define psllw_i2r(imm,reg) mmx_i2r (psllw, imm, reg) | ||
141 | #define psllw_m2r(var,reg) mmx_m2r (psllw, var, reg) | ||
142 | #define psllw_r2r(regs,regd) mmx_r2r (psllw, regs, regd) | ||
143 | |||
144 | #define psrad_i2r(imm,reg) mmx_i2r (psrad, imm, reg) | ||
145 | #define psrad_m2r(var,reg) mmx_m2r (psrad, var, reg) | ||
146 | #define psrad_r2r(regs,regd) mmx_r2r (psrad, regs, regd) | ||
147 | #define psraw_i2r(imm,reg) mmx_i2r (psraw, imm, reg) | ||
148 | #define psraw_m2r(var,reg) mmx_m2r (psraw, var, reg) | ||
149 | #define psraw_r2r(regs,regd) mmx_r2r (psraw, regs, regd) | ||
150 | |||
151 | #define psrld_i2r(imm,reg) mmx_i2r (psrld, imm, reg) | ||
152 | #define psrld_m2r(var,reg) mmx_m2r (psrld, var, reg) | ||
153 | #define psrld_r2r(regs,regd) mmx_r2r (psrld, regs, regd) | ||
154 | #define psrlq_i2r(imm,reg) mmx_i2r (psrlq, imm, reg) | ||
155 | #define psrlq_m2r(var,reg) mmx_m2r (psrlq, var, reg) | ||
156 | #define psrlq_r2r(regs,regd) mmx_r2r (psrlq, regs, regd) | ||
157 | #define psrlw_i2r(imm,reg) mmx_i2r (psrlw, imm, reg) | ||
158 | #define psrlw_m2r(var,reg) mmx_m2r (psrlw, var, reg) | ||
159 | #define psrlw_r2r(regs,regd) mmx_r2r (psrlw, regs, regd) | ||
160 | |||
161 | #define psubb_m2r(var,reg) mmx_m2r (psubb, var, reg) | ||
162 | #define psubb_r2r(regs,regd) mmx_r2r (psubb, regs, regd) | ||
163 | #define psubd_m2r(var,reg) mmx_m2r (psubd, var, reg) | ||
164 | #define psubd_r2r(regs,regd) mmx_r2r (psubd, regs, regd) | ||
165 | #define psubw_m2r(var,reg) mmx_m2r (psubw, var, reg) | ||
166 | #define psubw_r2r(regs,regd) mmx_r2r (psubw, regs, regd) | ||
167 | |||
168 | #define psubsb_m2r(var,reg) mmx_m2r (psubsb, var, reg) | ||
169 | #define psubsb_r2r(regs,regd) mmx_r2r (psubsb, regs, regd) | ||
170 | #define psubsw_m2r(var,reg) mmx_m2r (psubsw, var, reg) | ||
171 | #define psubsw_r2r(regs,regd) mmx_r2r (psubsw, regs, regd) | ||
172 | |||
173 | #define psubusb_m2r(var,reg) mmx_m2r (psubusb, var, reg) | ||
174 | #define psubusb_r2r(regs,regd) mmx_r2r (psubusb, regs, regd) | ||
175 | #define psubusw_m2r(var,reg) mmx_m2r (psubusw, var, reg) | ||
176 | #define psubusw_r2r(regs,regd) mmx_r2r (psubusw, regs, regd) | ||
177 | |||
178 | #define punpckhbw_m2r(var,reg) mmx_m2r (punpckhbw, var, reg) | ||
179 | #define punpckhbw_r2r(regs,regd) mmx_r2r (punpckhbw, regs, regd) | ||
180 | #define punpckhdq_m2r(var,reg) mmx_m2r (punpckhdq, var, reg) | ||
181 | #define punpckhdq_r2r(regs,regd) mmx_r2r (punpckhdq, regs, regd) | ||
182 | #define punpckhwd_m2r(var,reg) mmx_m2r (punpckhwd, var, reg) | ||
183 | #define punpckhwd_r2r(regs,regd) mmx_r2r (punpckhwd, regs, regd) | ||
184 | |||
185 | #define punpcklbw_m2r(var,reg) mmx_m2r (punpcklbw, var, reg) | ||
186 | #define punpcklbw_r2r(regs,regd) mmx_r2r (punpcklbw, regs, regd) | ||
187 | #define punpckldq_m2r(var,reg) mmx_m2r (punpckldq, var, reg) | ||
188 | #define punpckldq_r2r(regs,regd) mmx_r2r (punpckldq, regs, regd) | ||
189 | #define punpcklwd_m2r(var,reg) mmx_m2r (punpcklwd, var, reg) | ||
190 | #define punpcklwd_r2r(regs,regd) mmx_r2r (punpcklwd, regs, regd) | ||
191 | |||
192 | #define pxor_m2r(var,reg) mmx_m2r (pxor, var, reg) | ||
193 | #define pxor_r2r(regs,regd) mmx_r2r (pxor, regs, regd) | ||
194 | |||
195 | |||
196 | /* 3DNOW extensions */ | ||
197 | |||
198 | #define pavgusb_m2r(var,reg) mmx_m2r (pavgusb, var, reg) | ||
199 | #define pavgusb_r2r(regs,regd) mmx_r2r (pavgusb, regs, regd) | ||
200 | |||
201 | |||
202 | /* AMD MMX extensions - also available in intel SSE */ | ||
203 | |||
204 | |||
205 | #define mmx_m2ri(op,mem,reg,imm) \ | ||
206 | __asm__ __volatile__ (#op " %1, %0, %%" #reg \ | ||
207 | : /* nothing */ \ | ||
208 | : "m" (mem), "i" (imm)) | ||
209 | #define mmx_r2ri(op,regs,regd,imm) \ | ||
210 | __asm__ __volatile__ (#op " %0, %%" #regs ", %%" #regd \ | ||
211 | : /* nothing */ \ | ||
212 | : "i" (imm) ) | ||
213 | |||
214 | #define mmx_fetch(mem,hint) \ | ||
215 | __asm__ __volatile__ ("prefetch" #hint " %0" \ | ||
216 | : /* nothing */ \ | ||
217 | : "m" (mem)) | ||
218 | |||
219 | |||
220 | #define maskmovq(regs,maskreg) mmx_r2ri (maskmovq, regs, maskreg) | ||
221 | |||
222 | #define movntq_r2m(mmreg,var) mmx_r2m (movntq, mmreg, var) | ||
223 | |||
224 | #define pavgb_m2r(var,reg) mmx_m2r (pavgb, var, reg) | ||
225 | #define pavgb_r2r(regs,regd) mmx_r2r (pavgb, regs, regd) | ||
226 | #define pavgw_m2r(var,reg) mmx_m2r (pavgw, var, reg) | ||
227 | #define pavgw_r2r(regs,regd) mmx_r2r (pavgw, regs, regd) | ||
228 | |||
229 | #define pextrw_r2r(mmreg,reg,imm) mmx_r2ri (pextrw, mmreg, reg, imm) | ||
230 | |||
231 | #define pinsrw_r2r(reg,mmreg,imm) mmx_r2ri (pinsrw, reg, mmreg, imm) | ||
232 | |||
233 | #define pmaxsw_m2r(var,reg) mmx_m2r (pmaxsw, var, reg) | ||
234 | #define pmaxsw_r2r(regs,regd) mmx_r2r (pmaxsw, regs, regd) | ||
235 | |||
236 | #define pmaxub_m2r(var,reg) mmx_m2r (pmaxub, var, reg) | ||
237 | #define pmaxub_r2r(regs,regd) mmx_r2r (pmaxub, regs, regd) | ||
238 | |||
239 | #define pminsw_m2r(var,reg) mmx_m2r (pminsw, var, reg) | ||
240 | #define pminsw_r2r(regs,regd) mmx_r2r (pminsw, regs, regd) | ||
241 | |||
242 | #define pminub_m2r(var,reg) mmx_m2r (pminub, var, reg) | ||
243 | #define pminub_r2r(regs,regd) mmx_r2r (pminub, regs, regd) | ||
244 | |||
245 | #define pmovmskb(mmreg,reg) \ | ||
246 | __asm__ __volatile__ ("movmskps %" #mmreg ", %" #reg) | ||
247 | |||
248 | #define pmulhuw_m2r(var,reg) mmx_m2r (pmulhuw, var, reg) | ||
249 | #define pmulhuw_r2r(regs,regd) mmx_r2r (pmulhuw, regs, regd) | ||
250 | |||
251 | #define prefetcht0(mem) mmx_fetch (mem, t0) | ||
252 | #define prefetcht1(mem) mmx_fetch (mem, t1) | ||
253 | #define prefetcht2(mem) mmx_fetch (mem, t2) | ||
254 | #define prefetchnta(mem) mmx_fetch (mem, nta) | ||
255 | |||
256 | #define psadbw_m2r(var,reg) mmx_m2r (psadbw, var, reg) | ||
257 | #define psadbw_r2r(regs,regd) mmx_r2r (psadbw, regs, regd) | ||
258 | |||
259 | #define pshufw_m2r(var,reg,imm) mmx_m2ri(pshufw, var, reg, imm) | ||
260 | #define pshufw_r2r(regs,regd,imm) mmx_r2ri(pshufw, regs, regd, imm) | ||
261 | |||
262 | #define sfence() __asm__ __volatile__ ("sfence\n\t") | ||
263 | |||
264 | /* SSE2 */ | ||
265 | #define pshufhw_m2r(var,reg,imm) mmx_m2ri(pshufhw, var, reg, imm) | ||
266 | #define pshufhw_r2r(regs,regd,imm) mmx_r2ri(pshufhw, regs, regd, imm) | ||
267 | #define pshuflw_m2r(var,reg,imm) mmx_m2ri(pshuflw, var, reg, imm) | ||
268 | #define pshuflw_r2r(regs,regd,imm) mmx_r2ri(pshuflw, regs, regd, imm) | ||
269 | |||
270 | #define pshufd_r2r(regs,regd,imm) mmx_r2ri(pshufd, regs, regd, imm) | ||
271 | |||
272 | #define movdqa_m2r(var,reg) mmx_m2r (movdqa, var, reg) | ||
273 | #define movdqa_r2m(reg,var) mmx_r2m (movdqa, reg, var) | ||
274 | #define movdqa_r2r(regs,regd) mmx_r2r (movdqa, regs, regd) | ||
275 | #define movdqu_m2r(var,reg) mmx_m2r (movdqu, var, reg) | ||
276 | #define movdqu_r2m(reg,var) mmx_r2m (movdqu, reg, var) | ||
277 | #define movdqu_r2r(regs,regd) mmx_r2r (movdqu, regs, regd) | ||
278 | |||
279 | #define pmullw_r2m(reg,var) mmx_r2m (pmullw, reg, var) | ||
280 | |||
281 | #define pslldq_i2r(imm,reg) mmx_i2r (pslldq, imm, reg) | ||
282 | #define psrldq_i2r(imm,reg) mmx_i2r (psrldq, imm, reg) | ||
283 | |||
284 | #define punpcklqdq_r2r(regs,regd) mmx_r2r (punpcklqdq, regs, regd) | ||
285 | #define punpckhqdq_r2r(regs,regd) mmx_r2r (punpckhqdq, regs, regd) | ||
286 | |||
287 | |||
288 | #endif /* AVCODEC_I386MMX_H */ | ||