diff options
Diffstat (limited to 'sound/core/oss/rate.c')
-rw-r--r-- | sound/core/oss/rate.c | 378 |
1 files changed, 378 insertions, 0 deletions
diff --git a/sound/core/oss/rate.c b/sound/core/oss/rate.c new file mode 100644 index 000000000000..1096ec186714 --- /dev/null +++ b/sound/core/oss/rate.c | |||
@@ -0,0 +1,378 @@ | |||
1 | /* | ||
2 | * Rate conversion Plug-In | ||
3 | * Copyright (c) 1999 by Jaroslav Kysela <perex@suse.cz> | ||
4 | * | ||
5 | * | ||
6 | * This library is free software; you can redistribute it and/or modify | ||
7 | * it under the terms of the GNU Library General Public License as | ||
8 | * published by the Free Software Foundation; either version 2 of | ||
9 | * the License, or (at your option) any later version. | ||
10 | * | ||
11 | * This program is distributed in the hope that it will be useful, | ||
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
14 | * GNU Library General Public License for more details. | ||
15 | * | ||
16 | * You should have received a copy of the GNU Library General Public | ||
17 | * License along with this library; if not, write to the Free Software | ||
18 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | ||
19 | * | ||
20 | */ | ||
21 | |||
22 | #include <sound/driver.h> | ||
23 | #include <linux/time.h> | ||
24 | #include <sound/core.h> | ||
25 | #include <sound/pcm.h> | ||
26 | #include "pcm_plugin.h" | ||
27 | |||
28 | #define SHIFT 11 | ||
29 | #define BITS (1<<SHIFT) | ||
30 | #define R_MASK (BITS-1) | ||
31 | |||
32 | /* | ||
33 | * Basic rate conversion plugin | ||
34 | */ | ||
35 | |||
36 | typedef struct { | ||
37 | signed short last_S1; | ||
38 | signed short last_S2; | ||
39 | } rate_channel_t; | ||
40 | |||
41 | typedef void (*rate_f)(snd_pcm_plugin_t *plugin, | ||
42 | const snd_pcm_plugin_channel_t *src_channels, | ||
43 | snd_pcm_plugin_channel_t *dst_channels, | ||
44 | int src_frames, int dst_frames); | ||
45 | |||
46 | typedef struct rate_private_data { | ||
47 | unsigned int pitch; | ||
48 | unsigned int pos; | ||
49 | rate_f func; | ||
50 | int get, put; | ||
51 | snd_pcm_sframes_t old_src_frames, old_dst_frames; | ||
52 | rate_channel_t channels[0]; | ||
53 | } rate_t; | ||
54 | |||
55 | static void rate_init(snd_pcm_plugin_t *plugin) | ||
56 | { | ||
57 | unsigned int channel; | ||
58 | rate_t *data = (rate_t *)plugin->extra_data; | ||
59 | data->pos = 0; | ||
60 | for (channel = 0; channel < plugin->src_format.channels; channel++) { | ||
61 | data->channels[channel].last_S1 = 0; | ||
62 | data->channels[channel].last_S2 = 0; | ||
63 | } | ||
64 | } | ||
65 | |||
66 | static void resample_expand(snd_pcm_plugin_t *plugin, | ||
67 | const snd_pcm_plugin_channel_t *src_channels, | ||
68 | snd_pcm_plugin_channel_t *dst_channels, | ||
69 | int src_frames, int dst_frames) | ||
70 | { | ||
71 | unsigned int pos = 0; | ||
72 | signed int val; | ||
73 | signed short S1, S2; | ||
74 | char *src, *dst; | ||
75 | unsigned int channel; | ||
76 | int src_step, dst_step; | ||
77 | int src_frames1, dst_frames1; | ||
78 | rate_t *data = (rate_t *)plugin->extra_data; | ||
79 | rate_channel_t *rchannels = data->channels; | ||
80 | |||
81 | #define GET_S16_LABELS | ||
82 | #define PUT_S16_LABELS | ||
83 | #include "plugin_ops.h" | ||
84 | #undef GET_S16_LABELS | ||
85 | #undef PUT_S16_LABELS | ||
86 | void *get = get_s16_labels[data->get]; | ||
87 | void *put = put_s16_labels[data->put]; | ||
88 | signed short sample = 0; | ||
89 | |||
90 | for (channel = 0; channel < plugin->src_format.channels; channel++) { | ||
91 | pos = data->pos; | ||
92 | S1 = rchannels->last_S1; | ||
93 | S2 = rchannels->last_S2; | ||
94 | if (!src_channels[channel].enabled) { | ||
95 | if (dst_channels[channel].wanted) | ||
96 | snd_pcm_area_silence(&dst_channels[channel].area, 0, dst_frames, plugin->dst_format.format); | ||
97 | dst_channels[channel].enabled = 0; | ||
98 | continue; | ||
99 | } | ||
100 | dst_channels[channel].enabled = 1; | ||
101 | src = (char *)src_channels[channel].area.addr + src_channels[channel].area.first / 8; | ||
102 | dst = (char *)dst_channels[channel].area.addr + dst_channels[channel].area.first / 8; | ||
103 | src_step = src_channels[channel].area.step / 8; | ||
104 | dst_step = dst_channels[channel].area.step / 8; | ||
105 | src_frames1 = src_frames; | ||
106 | dst_frames1 = dst_frames; | ||
107 | while (dst_frames1-- > 0) { | ||
108 | if (pos & ~R_MASK) { | ||
109 | pos &= R_MASK; | ||
110 | S1 = S2; | ||
111 | if (src_frames1-- > 0) { | ||
112 | goto *get; | ||
113 | #define GET_S16_END after_get | ||
114 | #include "plugin_ops.h" | ||
115 | #undef GET_S16_END | ||
116 | after_get: | ||
117 | S2 = sample; | ||
118 | src += src_step; | ||
119 | } | ||
120 | } | ||
121 | val = S1 + ((S2 - S1) * (signed int)pos) / BITS; | ||
122 | if (val < -32768) | ||
123 | val = -32768; | ||
124 | else if (val > 32767) | ||
125 | val = 32767; | ||
126 | sample = val; | ||
127 | goto *put; | ||
128 | #define PUT_S16_END after_put | ||
129 | #include "plugin_ops.h" | ||
130 | #undef PUT_S16_END | ||
131 | after_put: | ||
132 | dst += dst_step; | ||
133 | pos += data->pitch; | ||
134 | } | ||
135 | rchannels->last_S1 = S1; | ||
136 | rchannels->last_S2 = S2; | ||
137 | rchannels++; | ||
138 | } | ||
139 | data->pos = pos; | ||
140 | } | ||
141 | |||
142 | static void resample_shrink(snd_pcm_plugin_t *plugin, | ||
143 | const snd_pcm_plugin_channel_t *src_channels, | ||
144 | snd_pcm_plugin_channel_t *dst_channels, | ||
145 | int src_frames, int dst_frames) | ||
146 | { | ||
147 | unsigned int pos = 0; | ||
148 | signed int val; | ||
149 | signed short S1, S2; | ||
150 | char *src, *dst; | ||
151 | unsigned int channel; | ||
152 | int src_step, dst_step; | ||
153 | int src_frames1, dst_frames1; | ||
154 | rate_t *data = (rate_t *)plugin->extra_data; | ||
155 | rate_channel_t *rchannels = data->channels; | ||
156 | |||
157 | #define GET_S16_LABELS | ||
158 | #define PUT_S16_LABELS | ||
159 | #include "plugin_ops.h" | ||
160 | #undef GET_S16_LABELS | ||
161 | #undef PUT_S16_LABELS | ||
162 | void *get = get_s16_labels[data->get]; | ||
163 | void *put = put_s16_labels[data->put]; | ||
164 | signed short sample = 0; | ||
165 | |||
166 | for (channel = 0; channel < plugin->src_format.channels; ++channel) { | ||
167 | pos = data->pos; | ||
168 | S1 = rchannels->last_S1; | ||
169 | S2 = rchannels->last_S2; | ||
170 | if (!src_channels[channel].enabled) { | ||
171 | if (dst_channels[channel].wanted) | ||
172 | snd_pcm_area_silence(&dst_channels[channel].area, 0, dst_frames, plugin->dst_format.format); | ||
173 | dst_channels[channel].enabled = 0; | ||
174 | continue; | ||
175 | } | ||
176 | dst_channels[channel].enabled = 1; | ||
177 | src = (char *)src_channels[channel].area.addr + src_channels[channel].area.first / 8; | ||
178 | dst = (char *)dst_channels[channel].area.addr + dst_channels[channel].area.first / 8; | ||
179 | src_step = src_channels[channel].area.step / 8; | ||
180 | dst_step = dst_channels[channel].area.step / 8; | ||
181 | src_frames1 = src_frames; | ||
182 | dst_frames1 = dst_frames; | ||
183 | while (dst_frames1 > 0) { | ||
184 | S1 = S2; | ||
185 | if (src_frames1-- > 0) { | ||
186 | goto *get; | ||
187 | #define GET_S16_END after_get | ||
188 | #include "plugin_ops.h" | ||
189 | #undef GET_S16_END | ||
190 | after_get: | ||
191 | S2 = sample; | ||
192 | src += src_step; | ||
193 | } | ||
194 | if (pos & ~R_MASK) { | ||
195 | pos &= R_MASK; | ||
196 | val = S1 + ((S2 - S1) * (signed int)pos) / BITS; | ||
197 | if (val < -32768) | ||
198 | val = -32768; | ||
199 | else if (val > 32767) | ||
200 | val = 32767; | ||
201 | sample = val; | ||
202 | goto *put; | ||
203 | #define PUT_S16_END after_put | ||
204 | #include "plugin_ops.h" | ||
205 | #undef PUT_S16_END | ||
206 | after_put: | ||
207 | dst += dst_step; | ||
208 | dst_frames1--; | ||
209 | } | ||
210 | pos += data->pitch; | ||
211 | } | ||
212 | rchannels->last_S1 = S1; | ||
213 | rchannels->last_S2 = S2; | ||
214 | rchannels++; | ||
215 | } | ||
216 | data->pos = pos; | ||
217 | } | ||
218 | |||
219 | static snd_pcm_sframes_t rate_src_frames(snd_pcm_plugin_t *plugin, snd_pcm_uframes_t frames) | ||
220 | { | ||
221 | rate_t *data; | ||
222 | snd_pcm_sframes_t res; | ||
223 | |||
224 | snd_assert(plugin != NULL, return -ENXIO); | ||
225 | if (frames == 0) | ||
226 | return 0; | ||
227 | data = (rate_t *)plugin->extra_data; | ||
228 | if (plugin->src_format.rate < plugin->dst_format.rate) { | ||
229 | res = (((frames * data->pitch) + (BITS/2)) >> SHIFT); | ||
230 | } else { | ||
231 | res = (((frames << SHIFT) + (data->pitch / 2)) / data->pitch); | ||
232 | } | ||
233 | if (data->old_src_frames > 0) { | ||
234 | snd_pcm_sframes_t frames1 = frames, res1 = data->old_dst_frames; | ||
235 | while (data->old_src_frames < frames1) { | ||
236 | frames1 >>= 1; | ||
237 | res1 <<= 1; | ||
238 | } | ||
239 | while (data->old_src_frames > frames1) { | ||
240 | frames1 <<= 1; | ||
241 | res1 >>= 1; | ||
242 | } | ||
243 | if (data->old_src_frames == frames1) | ||
244 | return res1; | ||
245 | } | ||
246 | data->old_src_frames = frames; | ||
247 | data->old_dst_frames = res; | ||
248 | return res; | ||
249 | } | ||
250 | |||
251 | static snd_pcm_sframes_t rate_dst_frames(snd_pcm_plugin_t *plugin, snd_pcm_uframes_t frames) | ||
252 | { | ||
253 | rate_t *data; | ||
254 | snd_pcm_sframes_t res; | ||
255 | |||
256 | snd_assert(plugin != NULL, return -ENXIO); | ||
257 | if (frames == 0) | ||
258 | return 0; | ||
259 | data = (rate_t *)plugin->extra_data; | ||
260 | if (plugin->src_format.rate < plugin->dst_format.rate) { | ||
261 | res = (((frames << SHIFT) + (data->pitch / 2)) / data->pitch); | ||
262 | } else { | ||
263 | res = (((frames * data->pitch) + (BITS/2)) >> SHIFT); | ||
264 | } | ||
265 | if (data->old_dst_frames > 0) { | ||
266 | snd_pcm_sframes_t frames1 = frames, res1 = data->old_src_frames; | ||
267 | while (data->old_dst_frames < frames1) { | ||
268 | frames1 >>= 1; | ||
269 | res1 <<= 1; | ||
270 | } | ||
271 | while (data->old_dst_frames > frames1) { | ||
272 | frames1 <<= 1; | ||
273 | res1 >>= 1; | ||
274 | } | ||
275 | if (data->old_dst_frames == frames1) | ||
276 | return res1; | ||
277 | } | ||
278 | data->old_dst_frames = frames; | ||
279 | data->old_src_frames = res; | ||
280 | return res; | ||
281 | } | ||
282 | |||
283 | static snd_pcm_sframes_t rate_transfer(snd_pcm_plugin_t *plugin, | ||
284 | const snd_pcm_plugin_channel_t *src_channels, | ||
285 | snd_pcm_plugin_channel_t *dst_channels, | ||
286 | snd_pcm_uframes_t frames) | ||
287 | { | ||
288 | snd_pcm_uframes_t dst_frames; | ||
289 | rate_t *data; | ||
290 | |||
291 | snd_assert(plugin != NULL && src_channels != NULL && dst_channels != NULL, return -ENXIO); | ||
292 | if (frames == 0) | ||
293 | return 0; | ||
294 | #ifdef CONFIG_SND_DEBUG | ||
295 | { | ||
296 | unsigned int channel; | ||
297 | for (channel = 0; channel < plugin->src_format.channels; channel++) { | ||
298 | snd_assert(src_channels[channel].area.first % 8 == 0 && | ||
299 | src_channels[channel].area.step % 8 == 0, | ||
300 | return -ENXIO); | ||
301 | snd_assert(dst_channels[channel].area.first % 8 == 0 && | ||
302 | dst_channels[channel].area.step % 8 == 0, | ||
303 | return -ENXIO); | ||
304 | } | ||
305 | } | ||
306 | #endif | ||
307 | |||
308 | dst_frames = rate_dst_frames(plugin, frames); | ||
309 | if (dst_frames > dst_channels[0].frames) | ||
310 | dst_frames = dst_channels[0].frames; | ||
311 | data = (rate_t *)plugin->extra_data; | ||
312 | data->func(plugin, src_channels, dst_channels, frames, dst_frames); | ||
313 | return dst_frames; | ||
314 | } | ||
315 | |||
316 | static int rate_action(snd_pcm_plugin_t *plugin, | ||
317 | snd_pcm_plugin_action_t action, | ||
318 | unsigned long udata ATTRIBUTE_UNUSED) | ||
319 | { | ||
320 | snd_assert(plugin != NULL, return -ENXIO); | ||
321 | switch (action) { | ||
322 | case INIT: | ||
323 | case PREPARE: | ||
324 | rate_init(plugin); | ||
325 | break; | ||
326 | default: | ||
327 | break; | ||
328 | } | ||
329 | return 0; /* silenty ignore other actions */ | ||
330 | } | ||
331 | |||
332 | int snd_pcm_plugin_build_rate(snd_pcm_plug_t *plug, | ||
333 | snd_pcm_plugin_format_t *src_format, | ||
334 | snd_pcm_plugin_format_t *dst_format, | ||
335 | snd_pcm_plugin_t **r_plugin) | ||
336 | { | ||
337 | int err; | ||
338 | rate_t *data; | ||
339 | snd_pcm_plugin_t *plugin; | ||
340 | |||
341 | snd_assert(r_plugin != NULL, return -ENXIO); | ||
342 | *r_plugin = NULL; | ||
343 | |||
344 | snd_assert(src_format->channels == dst_format->channels, return -ENXIO); | ||
345 | snd_assert(src_format->channels > 0, return -ENXIO); | ||
346 | snd_assert(snd_pcm_format_linear(src_format->format) != 0, return -ENXIO); | ||
347 | snd_assert(snd_pcm_format_linear(dst_format->format) != 0, return -ENXIO); | ||
348 | snd_assert(src_format->rate != dst_format->rate, return -ENXIO); | ||
349 | |||
350 | err = snd_pcm_plugin_build(plug, "rate conversion", | ||
351 | src_format, dst_format, | ||
352 | sizeof(rate_t) + src_format->channels * sizeof(rate_channel_t), | ||
353 | &plugin); | ||
354 | if (err < 0) | ||
355 | return err; | ||
356 | data = (rate_t *)plugin->extra_data; | ||
357 | data->get = getput_index(src_format->format); | ||
358 | snd_assert(data->get >= 0 && data->get < 4*2*2, return -EINVAL); | ||
359 | data->put = getput_index(dst_format->format); | ||
360 | snd_assert(data->put >= 0 && data->put < 4*2*2, return -EINVAL); | ||
361 | |||
362 | if (src_format->rate < dst_format->rate) { | ||
363 | data->pitch = ((src_format->rate << SHIFT) + (dst_format->rate >> 1)) / dst_format->rate; | ||
364 | data->func = resample_expand; | ||
365 | } else { | ||
366 | data->pitch = ((dst_format->rate << SHIFT) + (src_format->rate >> 1)) / src_format->rate; | ||
367 | data->func = resample_shrink; | ||
368 | } | ||
369 | data->pos = 0; | ||
370 | rate_init(plugin); | ||
371 | data->old_src_frames = data->old_dst_frames = 0; | ||
372 | plugin->transfer = rate_transfer; | ||
373 | plugin->src_frames = rate_src_frames; | ||
374 | plugin->dst_frames = rate_dst_frames; | ||
375 | plugin->action = rate_action; | ||
376 | *r_plugin = plugin; | ||
377 | return 0; | ||
378 | } | ||