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1 | Frequently Asked Questions: | ||
2 | =========================== | ||
3 | subject: unified zoran driver (zr360x7, zoran, buz, dc10(+), dc30(+), lml33) | ||
4 | website: http://mjpeg.sourceforge.net/driver-zoran/ | ||
5 | |||
6 | 1. What cards are supported | ||
7 | 1.1 What the TV decoder can do an what not | ||
8 | 1.2 What the TV encoder can do an what not | ||
9 | 2. How do I get this damn thing to work | ||
10 | 3. What mainboard should I use (or why doesn't my card work) | ||
11 | 4. Programming interface | ||
12 | 5. Applications | ||
13 | 6. Concerning buffer sizes, quality, output size etc. | ||
14 | 7. It hangs/crashes/fails/whatevers! Help! | ||
15 | 8. Maintainers/Contacting | ||
16 | 9. License | ||
17 | |||
18 | =========================== | ||
19 | |||
20 | 1. What cards are supported | ||
21 | |||
22 | Iomega Buz, Linux Media Labs LML33/LML33R10, Pinnacle/Miro | ||
23 | DC10/DC10+/DC30/DC30+ and related boards (available under various names). | ||
24 | |||
25 | Iomega Buz: | ||
26 | * Zoran zr36067 PCI controller | ||
27 | * Zoran zr36060 MJPEG codec | ||
28 | * Philips saa7111 TV decoder | ||
29 | * Philips saa7185 TV encoder | ||
30 | Drivers to use: videodev, i2c-core, i2c-algo-bit, | ||
31 | videocodec, saa7111, saa7185, zr36060, zr36067 | ||
32 | Inputs/outputs: Composite and S-video | ||
33 | Norms: PAL, SECAM (720x576 @ 25 fps), NTSC (720x480 @ 29.97 fps) | ||
34 | Card number: 7 | ||
35 | |||
36 | Linux Media Labs LML33: | ||
37 | * Zoran zr36067 PCI controller | ||
38 | * Zoran zr36060 MJPEG codec | ||
39 | * Brooktree bt819 TV decoder | ||
40 | * Brooktree bt856 TV encoder | ||
41 | Drivers to use: videodev, i2c-core, i2c-algo-bit, | ||
42 | videocodec, bt819, bt856, zr36060, zr36067 | ||
43 | Inputs/outputs: Composite and S-video | ||
44 | Norms: PAL (720x576 @ 25 fps), NTSC (720x480 @ 29.97 fps) | ||
45 | Card number: 5 | ||
46 | |||
47 | Linux Media Labs LML33R10: | ||
48 | * Zoran zr36067 PCI controller | ||
49 | * Zoran zr36060 MJPEG codec | ||
50 | * Philips saa7114 TV decoder | ||
51 | * Analog Devices adv7170 TV encoder | ||
52 | Drivers to use: videodev, i2c-core, i2c-algo-bit, | ||
53 | videocodec, saa7114, adv7170, zr36060, zr36067 | ||
54 | Inputs/outputs: Composite and S-video | ||
55 | Norms: PAL (720x576 @ 25 fps), NTSC (720x480 @ 29.97 fps) | ||
56 | Card number: 6 | ||
57 | |||
58 | Pinnacle/Miro DC10(new): | ||
59 | * Zoran zr36057 PCI controller | ||
60 | * Zoran zr36060 MJPEG codec | ||
61 | * Philips saa7110a TV decoder | ||
62 | * Analog Devices adv7176 TV encoder | ||
63 | Drivers to use: videodev, i2c-core, i2c-algo-bit, | ||
64 | videocodec, saa7110, adv7175, zr36060, zr36067 | ||
65 | Inputs/outputs: Composite, S-video and Internal | ||
66 | Norms: PAL, SECAM (768x576 @ 25 fps), NTSC (640x480 @ 29.97 fps) | ||
67 | Card number: 1 | ||
68 | |||
69 | Pinnacle/Miro DC10+: | ||
70 | * Zoran zr36067 PCI controller | ||
71 | * Zoran zr36060 MJPEG codec | ||
72 | * Philips saa7110a TV decoder | ||
73 | * Analog Devices adv7176 TV encoder | ||
74 | Drivers to use: videodev, i2c-core, i2c-algo-bit, | ||
75 | videocodec, sa7110, adv7175, zr36060, zr36067 | ||
76 | Inputs/outputs: Composite, S-video and Internal | ||
77 | Norms: PAL, SECAM (768x576 @ 25 fps), NTSC (640x480 @ 29.97 fps) | ||
78 | Card number: 2 | ||
79 | |||
80 | Pinnacle/Miro DC10(old): * | ||
81 | * Zoran zr36057 PCI controller | ||
82 | * Zoran zr36050 MJPEG codec | ||
83 | * Zoran zr36016 Video Front End or Fuji md0211 Video Front End (clone?) | ||
84 | * Micronas vpx3220a TV decoder | ||
85 | * mse3000 TV encoder or Analog Devices adv7176 TV encoder * | ||
86 | Drivers to use: videodev, i2c-core, i2c-algo-bit, | ||
87 | videocodec, vpx3220, mse3000/adv7175, zr36050, zr36016, zr36067 | ||
88 | Inputs/outputs: Composite, S-video and Internal | ||
89 | Norms: PAL, SECAM (768x576 @ 25 fps), NTSC (640x480 @ 29.97 fps) | ||
90 | Card number: 0 | ||
91 | |||
92 | Pinnacle/Miro DC30: * | ||
93 | * Zoran zr36057 PCI controller | ||
94 | * Zoran zr36050 MJPEG codec | ||
95 | * Zoran zr36016 Video Front End | ||
96 | * Micronas vpx3225d/vpx3220a/vpx3216b TV decoder | ||
97 | * Analog Devices adv7176 TV encoder | ||
98 | Drivers to use: videodev, i2c-core, i2c-algo-bit, | ||
99 | videocodec, vpx3220/vpx3224, adv7175, zr36050, zr36016, zr36067 | ||
100 | Inputs/outputs: Composite, S-video and Internal | ||
101 | Norms: PAL, SECAM (768x576 @ 25 fps), NTSC (640x480 @ 29.97 fps) | ||
102 | Card number: 3 | ||
103 | |||
104 | Pinnacle/Miro DC30+: * | ||
105 | * Zoran zr36067 PCI controller | ||
106 | * Zoran zr36050 MJPEG codec | ||
107 | * Zoran zr36016 Video Front End | ||
108 | * Micronas vpx3225d/vpx3220a/vpx3216b TV decoder | ||
109 | * Analog Devices adv7176 TV encoder | ||
110 | Drivers to use: videodev, i2c-core, i2c-algo-bit, | ||
111 | videocodec, vpx3220/vpx3224, adv7175, zr36050, zr36015, zr36067 | ||
112 | Inputs/outputs: Composite, S-video and Internal | ||
113 | Norms: PAL, SECAM (768x576 @ 25 fps), NTSC (640x480 @ 29.97 fps) | ||
114 | Card number: 4 | ||
115 | |||
116 | Note: No module for the mse3000 is available yet | ||
117 | Note: No module for the vpx3224 is available yet | ||
118 | Note: use encoder=X or decoder=X for non-default i2c chips (see i2c-id.h) | ||
119 | |||
120 | =========================== | ||
121 | |||
122 | 1.1 What the TV decoder can do an what not | ||
123 | |||
124 | The best know TV standards are NTSC/PAL/SECAM. but for decoding a frame that | ||
125 | information is not enough. There are several formats of the TV standards. | ||
126 | And not every TV decoder is able to handle every format. Also the every | ||
127 | combination is supported by the driver. There are currently 11 different | ||
128 | tv broadcast formats all aver the world. | ||
129 | |||
130 | The CCIR defines parameters needed for broadcasting the signal. | ||
131 | The CCIR has defined different standards: A,B,D,E,F,G,D,H,I,K,K1,L,M,N,... | ||
132 | The CCIR says not much about about the colorsystem used !!! | ||
133 | And talking about a colorsystem says not to much about how it is broadcast. | ||
134 | |||
135 | The CCIR standards A,E,F are not used any more. | ||
136 | |||
137 | When you speak about NTSC, you usually mean the standard: CCIR - M using | ||
138 | the NTSC colorsystem which is used in the USA, Japan, Mexico, Canada | ||
139 | and a few others. | ||
140 | |||
141 | When you talk about PAL, you usually mean: CCIR - B/G using the PAL | ||
142 | colorsystem which is used in many Countries. | ||
143 | |||
144 | When you talk about SECAM, you mean: CCIR - L using the SECAM Colorsystem | ||
145 | which is used in France, and a few others. | ||
146 | |||
147 | There the other version of SECAM, CCIR - D/K is used in Bulgaria, China, | ||
148 | Slovakai, Hungary, Korea (Rep.), Poland, Rumania and a others. | ||
149 | |||
150 | The CCIR - H uses the PAL colorsystem (sometimes SECAM) and is used in | ||
151 | Egypt, Libya, Sri Lanka, Syrain Arab. Rep. | ||
152 | |||
153 | The CCIR - I uses the PAL colorsystem, and is used in Great Britain, Hong Kong, | ||
154 | Ireland, Nigeria, South Africa. | ||
155 | |||
156 | The CCIR - N uses the PAL colorsystem and PAL frame size but the NTSC framerate, | ||
157 | and is used in Argentinia, Uruguay, an a few others | ||
158 | |||
159 | We do not talk about how the audio is broadcast ! | ||
160 | |||
161 | A rather good sites about the TV standards are: | ||
162 | http://www.sony.jp/ServiceArea/Voltage_map/ | ||
163 | http://info.electronicwerkstatt.de/bereiche/fernsehtechnik/frequenzen_und_normen/Fernsehnormen/ | ||
164 | and http://www.cabl.com/restaurant/channel.html | ||
165 | |||
166 | Other weird things around: NTSC 4.43 is a modificated NTSC, which is mainly | ||
167 | used in PAL VCR's that are able to play back NTSC. PAL 60 seems to be the same | ||
168 | as NTSC 4.43 . The Datasheets also talk about NTSC 44, It seems as if it would | ||
169 | be the same as NTSC 4.43. | ||
170 | NTSC Combs seems to be a decoder mode where the decoder uses a comb filter | ||
171 | to split coma and luma instead of a Delay line. | ||
172 | |||
173 | But I did not defiantly find out what NTSC Comb is. | ||
174 | |||
175 | Philips saa7111 TV decoder | ||
176 | was introduced in 1997, is used in the BUZ and | ||
177 | can handle: PAL B/G/H/I, PAL N, PAL M, NTSC M, NTSC N, NTSC 4.43 and SECAM | ||
178 | |||
179 | Philips saa7110a TV decoder | ||
180 | was introduced in 1995, is used in the Pinnacle/Miro DC10(new), DC10+ and | ||
181 | can handle: PAL B/G, NTSC M and SECAM | ||
182 | |||
183 | Philips saa7114 TV decoder | ||
184 | was introduced in 2000, is used in the LML33R10 and | ||
185 | can handle: PAL B/G/D/H/I/N, PAL N, PAL M, NTSC M, NTSC 4.43 and SECAM | ||
186 | |||
187 | Brooktree bt819 TV decoder | ||
188 | was introduced in 1996, and is used in the LML33 and | ||
189 | can handle: PAL B/D/G/H/I, NTSC M | ||
190 | |||
191 | Micronas vpx3220a TV decoder | ||
192 | was introduced in 1996, is used in the DC30 and DC30+ and | ||
193 | can handle: PAL B/G/H/I, PAL N, PAL M, NTSC M, NTSC 44, PAL 60, SECAM,NTSC Comb | ||
194 | |||
195 | =========================== | ||
196 | |||
197 | 1.2 What the TV encoder can do an what not | ||
198 | |||
199 | The TV encoder are doing the "same" as the decoder, but in the oder direction. | ||
200 | You feed them digital data and the generate a Composite or SVHS signal. | ||
201 | For information about the colorsystems and TV norm take a look in the | ||
202 | TV decoder section. | ||
203 | |||
204 | Philips saa7185 TV Encoder | ||
205 | was introduced in 1996, is used in the BUZ | ||
206 | can generate: PAL B/G, NTSC M | ||
207 | |||
208 | Brooktree bt856 TV Encoder | ||
209 | was introduced in 1994, is used in the LML33 | ||
210 | can generate: PAL B/D/G/H/I/N, PAL M, NTSC M, PAL-N (Argentina) | ||
211 | |||
212 | Analog Devices adv7170 TV Encoder | ||
213 | was introduced in 2000, is used in the LML300R10 | ||
214 | can generate: PAL B/D/G/H/I/N, PAL M, NTSC M, PAL 60 | ||
215 | |||
216 | Analog Devices adv7175 TV Encoder | ||
217 | was introduced in 1996, is used in the DC10, DC10+, DC10 old, DC30, DC30+ | ||
218 | can generate: PAL B/D/G/H/I/N, PAL M, NTSC M | ||
219 | |||
220 | ITT mse3000 TV encoder | ||
221 | was introduced in 1991, is used in the DC10 old | ||
222 | can generate: PAL , NTSC , SECAM | ||
223 | |||
224 | The adv717x, should be able to produce PAL N. But you find nothing PAL N | ||
225 | specific in the the registers. Seem that you have to reuse a other standard | ||
226 | to generate PAL N, maybe it would work if you use the PAL M settings. | ||
227 | |||
228 | ========================== | ||
229 | |||
230 | 2. How do I get this damn thing to work | ||
231 | |||
232 | Load zr36067.o. If it can't autodetect your card, use the card=X insmod | ||
233 | option with X being the card number as given in the previous section. | ||
234 | To have more than one card, use card=X1[,X2[,X3,[X4[..]]]] | ||
235 | |||
236 | To automate this, add the following to your /etc/modprobe.conf: | ||
237 | |||
238 | options zr36067 card=X1[,X2[,X3[,X4[..]]]] | ||
239 | alias char-major-81-0 zr36067 | ||
240 | |||
241 | One thing to keep in mind is that this doesn't load zr36067.o itself yet. It | ||
242 | just automates loading. If you start using xawtv, the device won't load on | ||
243 | some systems, since you're trying to load modules as a user, which is not | ||
244 | allowed ("permission denied"). A quick workaround is to add 'Load "v4l"' to | ||
245 | XF86Config-4 when you use X by default, or to run 'v4l-conf -c <device>' in | ||
246 | one of your startup scripts (normally rc.local) if you don't use X. Both | ||
247 | make sure that the modules are loaded on startup, under the root account. | ||
248 | |||
249 | =========================== | ||
250 | |||
251 | 3. What mainboard should I use (or why doesn't my card work) | ||
252 | |||
253 | <insert lousy disclaimer here>. In short: good=SiS/Intel, bad=VIA. | ||
254 | |||
255 | Experience tells us that people with a Buz, on average, have more problems | ||
256 | than users with a DC10+/LML33. Also, it tells us that people owning a VIA- | ||
257 | based mainboard (ktXXX, MVP3) have more problems than users with a mainboard | ||
258 | based on a different chipset. Here's some notes from Andrew Stevens: | ||
259 | -- | ||
260 | Here's my experience of using LML33 and Buz on various motherboards: | ||
261 | |||
262 | VIA MVP3 | ||
263 | Forget it. Pointless. Doesn't work. | ||
264 | Intel 430FX (Pentium 200) | ||
265 | LML33 perfect, Buz tolerable (3 or 4 frames dropped per movie) | ||
266 | Intel 440BX (early stepping) | ||
267 | LML33 tolerable. Buz starting to get annoying (6-10 frames/hour) | ||
268 | Intel 440BX (late stepping) | ||
269 | Buz tolerable, LML3 almost perfect (occasional single frame drops) | ||
270 | SiS735 | ||
271 | LML33 perfect, Buz tolerable. | ||
272 | VIA KT133(*) | ||
273 | LML33 starting to get annoying, Buz poor enough that I have up. | ||
274 | |||
275 | Both 440BX boards were dual CPU versions. | ||
276 | -- | ||
277 | Bernhard Praschinger later added: | ||
278 | -- | ||
279 | AMD 751 | ||
280 | Buz perfect-tolerable | ||
281 | AMD 760 | ||
282 | Buz perfect-tolerable | ||
283 | -- | ||
284 | In general, people on the user mailinglist won't give you much of a chance | ||
285 | if you have a VIA-based motherboard. They may be cheap, but sometimes, you'd | ||
286 | rather want to spend some more money on better boards. In general, VIA | ||
287 | mainboard's IDE/PCI performance will also suck badly compared to others. | ||
288 | You'll noticed the DC10+/DC30+ aren't mentioned anywhere in the overview. | ||
289 | Basically, you can assume that if the Buz works, the LML33 will work too. If | ||
290 | the LML33 works, the DC10+/DC30+ will work too. They're most tolerant to | ||
291 | different mainboard chipsets from all of the supported cards. | ||
292 | |||
293 | If you experience timeouts during capture, buy a better mainboard or lower | ||
294 | the quality/buffersize during capture (see 'Concerning buffer sizes, quality, | ||
295 | output size etc.'). If it hangs, there's little we can do as of now. Check | ||
296 | your IRQs and make sure the card has its own interrupts. | ||
297 | |||
298 | =========================== | ||
299 | |||
300 | 4. Programming interface | ||
301 | |||
302 | This driver conforms to video4linux and video4linux2, both can be used to | ||
303 | use the driver. Since video4linux didn't provide adequate calls to fully | ||
304 | use the cards' features, we've introduced several programming extensions, | ||
305 | which are currently officially accepted in the 2.4.x branch of the kernel. | ||
306 | These extensions are known as the v4l/mjpeg extensions. See zoran.h for | ||
307 | details (structs/ioctls). | ||
308 | |||
309 | Information - video4linux: | ||
310 | http://roadrunner.swansea.linux.org.uk/v4lapi.shtml | ||
311 | Documentation/video4linux/API.html | ||
312 | /usr/include/linux/videodev.h | ||
313 | |||
314 | Information - video4linux/mjpeg extensions: | ||
315 | ./zoran.h | ||
316 | (also see below) | ||
317 | |||
318 | Information - video4linux2: | ||
319 | http://www.thedirks.org/v4l2/ | ||
320 | /usr/include/linux/videodev2.h | ||
321 | http://www.bytesex.org/v4l/ | ||
322 | |||
323 | More information on the video4linux/mjpeg extensions, by Serguei | ||
324 | Miridonovi and Rainer Johanni: | ||
325 | -- | ||
326 | The ioctls for that interface are as follows: | ||
327 | |||
328 | BUZIOC_G_PARAMS | ||
329 | BUZIOC_S_PARAMS | ||
330 | |||
331 | Get and set the parameters of the buz. The user should always do a | ||
332 | BUZIOC_G_PARAMS (with a struct buz_params) to obtain the default | ||
333 | settings, change what he likes and then make a BUZIOC_S_PARAMS call. | ||
334 | |||
335 | BUZIOC_REQBUFS | ||
336 | |||
337 | Before being able to capture/playback, the user has to request | ||
338 | the buffers he is wanting to use. Fill the structure | ||
339 | zoran_requestbuffers with the size (recommended: 256*1024) and | ||
340 | the number (recommended 32 up to 256). There are no such restrictions | ||
341 | as for the Video for Linux buffers, you should LEAVE SUFFICIENT | ||
342 | MEMORY for your system however, else strange things will happen .... | ||
343 | On return, the zoran_requestbuffers structure contains number and | ||
344 | size of the actually allocated buffers. | ||
345 | You should use these numbers for doing a mmap of the buffers | ||
346 | into the user space. | ||
347 | The BUZIOC_REQBUFS ioctl also makes it happen, that the next mmap | ||
348 | maps the MJPEG buffer instead of the V4L buffers. | ||
349 | |||
350 | BUZIOC_QBUF_CAPT | ||
351 | BUZIOC_QBUF_PLAY | ||
352 | |||
353 | Queue a buffer for capture or playback. The first call also starts | ||
354 | streaming capture. When streaming capture is going on, you may | ||
355 | only queue further buffers or issue syncs until streaming | ||
356 | capture is switched off again with a argument of -1 to | ||
357 | a BUZIOC_QBUF_CAPT/BUZIOC_QBUF_PLAY ioctl. | ||
358 | |||
359 | BUZIOC_SYNC | ||
360 | |||
361 | Issue this ioctl when all buffers are queued. This ioctl will | ||
362 | block until the first buffer becomes free for saving its | ||
363 | data to disk (after BUZIOC_QBUF_CAPT) or for reuse (after BUZIOC_QBUF_PLAY). | ||
364 | |||
365 | BUZIOC_G_STATUS | ||
366 | |||
367 | Get the status of the input lines (video source connected/norm). | ||
368 | |||
369 | For programming example, please, look at lavrec.c and lavplay.c code in | ||
370 | lavtools-1.2p2 package (URL: http://www.cicese.mx/~mirsev/DC10plus/) | ||
371 | and the 'examples' directory in the original Buz driver distribution. | ||
372 | |||
373 | Additional notes for software developers: | ||
374 | |||
375 | The driver returns maxwidth and maxheight parameters according to | ||
376 | the current TV standard (norm). Therefore, the software which | ||
377 | communicates with the driver and "asks" for these parameters should | ||
378 | first set the correct norm. Well, it seems logically correct: TV | ||
379 | standard is "more constant" for current country than geometry | ||
380 | settings of a variety of TV capture cards which may work in ITU or | ||
381 | square pixel format. Remember that users now can lock the norm to | ||
382 | avoid any ambiguity. | ||
383 | -- | ||
384 | Please note that lavplay/lavrec are also included in the MJPEG-tools | ||
385 | (http://mjpeg.sf.net/). | ||
386 | |||
387 | =========================== | ||
388 | |||
389 | 5. Applications | ||
390 | |||
391 | Applications known to work with this driver: | ||
392 | |||
393 | TV viewing: | ||
394 | * xawtv | ||
395 | * kwintv | ||
396 | * probably any TV application that supports video4linux or video4linux2. | ||
397 | |||
398 | MJPEG capture/playback: | ||
399 | * mjpegtools/lavtools (or Linux Video Studio) | ||
400 | * gstreamer | ||
401 | * mplayer | ||
402 | |||
403 | General raw capture: | ||
404 | * xawtv | ||
405 | * gstreamer | ||
406 | * probably any application that supports video4linux or video4linux2 | ||
407 | |||
408 | Video editing: | ||
409 | * Cinelerra | ||
410 | * MainActor | ||
411 | * mjpegtools (or Linux Video Studio) | ||
412 | |||
413 | =========================== | ||
414 | |||
415 | 6. Concerning buffer sizes, quality, output size etc. | ||
416 | |||
417 | The zr36060 can do 1:2 JPEG compression. This is really the theoretical | ||
418 | maximum that the chipset can reach. The driver can, however, limit compression | ||
419 | to a maximum (size) of 1:4. The reason for this is that some cards (e.g. Buz) | ||
420 | can't handle 1:2 compression without stopping capture after only a few minutes. | ||
421 | With 1:4, it'll mostly work. If you have a Buz, use 'low_bitrate=1' to go into | ||
422 | 1:4 max. compression mode. | ||
423 | |||
424 | 100% JPEG quality is thus 1:2 compression in practice. So for a full PAL frame | ||
425 | (size 720x576). The JPEG fields are stored in YUY2 format, so the size of the | ||
426 | fields are 720x288x16/2 bits/field (2 fields/frame) = 207360 bytes/field x 2 = | ||
427 | 414720 bytes/frame (add some more bytes for headers and DHT (huffman)/DQT | ||
428 | (quantization) tables, and you'll get to something like 512kB per frame for | ||
429 | 1:2 compression. For 1:4 compression, you'd have frames of half this size. | ||
430 | |||
431 | Some additional explanation by Martin Samuelsson, which also explains the | ||
432 | importance of buffer sizes: | ||
433 | -- | ||
434 | > Hmm, I do not think it is really that way. With the current (downloaded | ||
435 | > at 18:00 Monday) driver I get that output sizes for 10 sec: | ||
436 | > -q 50 -b 128 : 24.283.332 Bytes | ||
437 | > -q 50 -b 256 : 48.442.368 | ||
438 | > -q 25 -b 128 : 24.655.992 | ||
439 | > -q 25 -b 256 : 25.859.820 | ||
440 | |||
441 | I woke up, and can't go to sleep again. I'll kill some time explaining why | ||
442 | this doesn't look strange to me. | ||
443 | |||
444 | Let's do some math using a width of 704 pixels. I'm not sure whether the Buz | ||
445 | actually use that number or not, but that's not too important right now. | ||
446 | |||
447 | 704x288 pixels, one field, is 202752 pixels. Divided by 64 pixels per block; | ||
448 | 3168 blocks per field. Each pixel consist of two bytes; 128 bytes per block; | ||
449 | 1024 bits per block. 100% in the new driver mean 1:2 compression; the maximum | ||
450 | output becomes 512 bits per block. Actually 510, but 512 is simpler to use | ||
451 | for calculations. | ||
452 | |||
453 | Let's say that we specify d1q50. We thus want 256 bits per block; times 3168 | ||
454 | becomes 811008 bits; 101376 bytes per field. We're talking raw bits and bytes | ||
455 | here, so we don't need to do any fancy corrections for bits-per-pixel or such | ||
456 | things. 101376 bytes per field. | ||
457 | |||
458 | d1 video contains two fields per frame. Those sum up to 202752 bytes per | ||
459 | frame, and one of those frames goes into each buffer. | ||
460 | |||
461 | But wait a second! -b128 gives 128kB buffers! It's not possible to cram | ||
462 | 202752 bytes of JPEG data into 128kB! | ||
463 | |||
464 | This is what the driver notice and automatically compensate for in your | ||
465 | examples. Let's do some math using this information: | ||
466 | |||
467 | 128kB is 131072 bytes. In this buffer, we want to store two fields, which | ||
468 | leaves 65536 bytes for each field. Using 3168 blocks per field, we get | ||
469 | 20.68686868... available bytes per block; 165 bits. We can't allow the | ||
470 | request for 256 bits per block when there's only 165 bits available! The -q50 | ||
471 | option is silently overridden, and the -b128 option takes precedence, leaving | ||
472 | us with the equivalence of -q32. | ||
473 | |||
474 | This gives us a data rate of 165 bits per block, which, times 3168, sums up | ||
475 | to 65340 bytes per field, out of the allowed 65536. The current driver has | ||
476 | another level of rate limiting; it won't accept -q values that fill more than | ||
477 | 6/8 of the specified buffers. (I'm not sure why. "Playing it safe" seem to be | ||
478 | a safe bet. Personally, I think I would have lowered requested-bits-per-block | ||
479 | by one, or something like that.) We can't use 165 bits per block, but have to | ||
480 | lower it again, to 6/8 of the available buffer space: We end up with 124 bits | ||
481 | per block, the equivalence of -q24. With 128kB buffers, you can't use greater | ||
482 | than -q24 at -d1. (And PAL, and 704 pixels width...) | ||
483 | |||
484 | The third example is limited to -q24 through the same process. The second | ||
485 | example, using very similar calculations, is limited to -q48. The only | ||
486 | example that actually grab at the specified -q value is the last one, which | ||
487 | is clearly visible, looking at the file size. | ||
488 | -- | ||
489 | |||
490 | Conclusion: the quality of the resulting movie depends on buffer size, quality, | ||
491 | whether or not you use 'low_bitrate=1' as insmod option for the zr36060.c | ||
492 | module to do 1:4 instead of 1:2 compression, etc. | ||
493 | |||
494 | If you experience timeouts, lowering the quality/buffersize or using | ||
495 | 'low_bitrate=1 as insmod option for zr36060.o might actually help, as is | ||
496 | proven by the Buz. | ||
497 | |||
498 | =========================== | ||
499 | |||
500 | 7. It hangs/crashes/fails/whatevers! Help! | ||
501 | |||
502 | Make sure that the card has its own interrupts (see /proc/interrupts), check | ||
503 | the output of dmesg at high verbosity (load zr36067.o with debug=2, | ||
504 | load all other modules with debug=1). Check that your mainboard is favorable | ||
505 | (see question 2) and if not, test the card in another computer. Also see the | ||
506 | notes given in question 3 and try lowering quality/buffersize/capturesize | ||
507 | if recording fails after a period of time. | ||
508 | |||
509 | If all this doesn't help, give a clear description of the problem including | ||
510 | detailed hardware information (memory+brand, mainboard+chipset+brand, which | ||
511 | MJPEG card, processor, other PCI cards that might be of interest), give the | ||
512 | system PnP information (/proc/interrupts, /proc/dma, /proc/devices), and give | ||
513 | the kernel version, driver version, glibc version, gcc version and any other | ||
514 | information that might possibly be of interest. Also provide the dmesg output | ||
515 | at high verbosity. See 'Contacting' on how to contact the developers. | ||
516 | |||
517 | =========================== | ||
518 | |||
519 | 8. Maintainers/Contacting | ||
520 | |||
521 | The driver is currently maintained by Laurent Pinchart and Ronald Bultje | ||
522 | (<laurent.pinchart@skynet.be> and <rbultje@ronald.bitfreak.net>). For bug | ||
523 | reports or questions, please contact the mailinglist instead of the developers | ||
524 | individually. For user questions (i.e. bug reports or how-to questions), send | ||
525 | an email to <mjpeg-users@lists.sf.net>, for developers (i.e. if you want to | ||
526 | help programming), send an email to <mjpeg-developer@lists.sf.net>. See | ||
527 | http://www.sf.net/projects/mjpeg/ for subscription information. | ||
528 | |||
529 | For bug reports, be sure to include all the information as described in | ||
530 | the section 'It hangs/crashes/fails/whatevers! Help!'. Please make sure | ||
531 | you're using the latest version (http://mjpeg.sf.net/driver-zoran/). | ||
532 | |||
533 | Previous maintainers/developers of this driver include Serguei Miridonov | ||
534 | <mirsev@cicese.mx>, Wolfgang Scherr <scherr@net4you.net>, Dave Perks | ||
535 | <dperks@ibm.net> and Rainer Johanni <Rainer@Johanni.de>. | ||
536 | |||
537 | =========================== | ||
538 | |||
539 | 9. License | ||
540 | |||
541 | This driver is distributed under the terms of the General Public License. | ||
542 | |||
543 | This program is free software; you can redistribute it and/or modify | ||
544 | it under the terms of the GNU General Public License as published by | ||
545 | the Free Software Foundation; either version 2 of the License, or | ||
546 | (at your option) any later version. | ||
547 | |||
548 | This program is distributed in the hope that it will be useful, | ||
549 | but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
550 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
551 | GNU General Public License for more details. | ||
552 | |||
553 | You should have received a copy of the GNU General Public License | ||
554 | along with this program; if not, write to the Free Software | ||
555 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | ||
556 | |||
557 | See http://www.gnu.org/ for more information. | ||