blob: 040a2c841ae96352365d0048c07744661de7b631 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001Frequently Asked Questions:
2===========================
3subject: unified zoran driver (zr360x7, zoran, buz, dc10(+), dc30(+), lml33)
4website: http://mjpeg.sourceforge.net/driver-zoran/
5
61. What cards are supported
71.1 What the TV decoder can do an what not
81.2 What the TV encoder can do an what not
92. How do I get this damn thing to work
103. What mainboard should I use (or why doesn't my card work)
114. Programming interface
125. Applications
136. Concerning buffer sizes, quality, output size etc.
147. It hangs/crashes/fails/whatevers! Help!
158. Maintainers/Contacting
169. License
17
18===========================
19
201. What cards are supported
21
22Iomega Buz, Linux Media Labs LML33/LML33R10, Pinnacle/Miro
23DC10/DC10+/DC30/DC30+ and related boards (available under various names).
24
25Iomega Buz:
26* Zoran zr36067 PCI controller
27* Zoran zr36060 MJPEG codec
28* Philips saa7111 TV decoder
29* Philips saa7185 TV encoder
30Drivers to use: videodev, i2c-core, i2c-algo-bit,
Mauro Carvalho Chehab48773e62006-03-25 09:21:43 -030031 videocodec, saa7111, saa7185, zr36060, zr36067
Linus Torvalds1da177e2005-04-16 15:20:36 -070032Inputs/outputs: Composite and S-video
33Norms: PAL, SECAM (720x576 @ 25 fps), NTSC (720x480 @ 29.97 fps)
34Card number: 7
35
Martin Samuelssonfbe60da2006-04-27 10:17:00 -030036AverMedia 6 Eyes AVS6EYES:
37* Zoran zr36067 PCI controller
38* Zoran zr36060 MJPEG codec
39* Samsung ks0127 TV decoder
40* Conexant bt866 TV encoder
41Drivers to use: videodev, i2c-core, i2c-algo-bit,
42 videocodec, ks0127, bt866, zr36060, zr36067
43Inputs/outputs: Six physical inputs. 1-6 are composite,
44 1-2, 3-4, 5-6 doubles as S-video,
45 1-3 triples as component.
46 One composite output.
47Norms: PAL, SECAM (720x576 @ 25 fps), NTSC (720x480 @ 29.97 fps)
48Card number: 8
49Not autodetected, card=8 is necessary.
50
Linus Torvalds1da177e2005-04-16 15:20:36 -070051Linux Media Labs LML33:
52* Zoran zr36067 PCI controller
53* Zoran zr36060 MJPEG codec
54* Brooktree bt819 TV decoder
55* Brooktree bt856 TV encoder
56Drivers to use: videodev, i2c-core, i2c-algo-bit,
Mauro Carvalho Chehab48773e62006-03-25 09:21:43 -030057 videocodec, bt819, bt856, zr36060, zr36067
Linus Torvalds1da177e2005-04-16 15:20:36 -070058Inputs/outputs: Composite and S-video
59Norms: PAL (720x576 @ 25 fps), NTSC (720x480 @ 29.97 fps)
60Card number: 5
61
62Linux Media Labs LML33R10:
63* Zoran zr36067 PCI controller
64* Zoran zr36060 MJPEG codec
65* Philips saa7114 TV decoder
66* Analog Devices adv7170 TV encoder
67Drivers to use: videodev, i2c-core, i2c-algo-bit,
Mauro Carvalho Chehab48773e62006-03-25 09:21:43 -030068 videocodec, saa7114, adv7170, zr36060, zr36067
Linus Torvalds1da177e2005-04-16 15:20:36 -070069Inputs/outputs: Composite and S-video
70Norms: PAL (720x576 @ 25 fps), NTSC (720x480 @ 29.97 fps)
71Card number: 6
72
73Pinnacle/Miro DC10(new):
74* Zoran zr36057 PCI controller
75* Zoran zr36060 MJPEG codec
76* Philips saa7110a TV decoder
77* Analog Devices adv7176 TV encoder
78Drivers to use: videodev, i2c-core, i2c-algo-bit,
Mauro Carvalho Chehab48773e62006-03-25 09:21:43 -030079 videocodec, saa7110, adv7175, zr36060, zr36067
Linus Torvalds1da177e2005-04-16 15:20:36 -070080Inputs/outputs: Composite, S-video and Internal
81Norms: PAL, SECAM (768x576 @ 25 fps), NTSC (640x480 @ 29.97 fps)
82Card number: 1
83
84Pinnacle/Miro DC10+:
85* Zoran zr36067 PCI controller
86* Zoran zr36060 MJPEG codec
87* Philips saa7110a TV decoder
88* Analog Devices adv7176 TV encoder
89Drivers to use: videodev, i2c-core, i2c-algo-bit,
90 videocodec, sa7110, adv7175, zr36060, zr36067
91Inputs/outputs: Composite, S-video and Internal
92Norms: PAL, SECAM (768x576 @ 25 fps), NTSC (640x480 @ 29.97 fps)
93Card number: 2
94
95Pinnacle/Miro DC10(old): *
96* Zoran zr36057 PCI controller
97* Zoran zr36050 MJPEG codec
98* Zoran zr36016 Video Front End or Fuji md0211 Video Front End (clone?)
99* Micronas vpx3220a TV decoder
100* mse3000 TV encoder or Analog Devices adv7176 TV encoder *
101Drivers to use: videodev, i2c-core, i2c-algo-bit,
Mauro Carvalho Chehab48773e62006-03-25 09:21:43 -0300102 videocodec, vpx3220, mse3000/adv7175, zr36050, zr36016, zr36067
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103Inputs/outputs: Composite, S-video and Internal
104Norms: PAL, SECAM (768x576 @ 25 fps), NTSC (640x480 @ 29.97 fps)
105Card number: 0
106
107Pinnacle/Miro DC30: *
108* Zoran zr36057 PCI controller
109* Zoran zr36050 MJPEG codec
110* Zoran zr36016 Video Front End
111* Micronas vpx3225d/vpx3220a/vpx3216b TV decoder
112* Analog Devices adv7176 TV encoder
113Drivers to use: videodev, i2c-core, i2c-algo-bit,
Mauro Carvalho Chehab48773e62006-03-25 09:21:43 -0300114 videocodec, vpx3220/vpx3224, adv7175, zr36050, zr36016, zr36067
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115Inputs/outputs: Composite, S-video and Internal
116Norms: PAL, SECAM (768x576 @ 25 fps), NTSC (640x480 @ 29.97 fps)
117Card number: 3
118
119Pinnacle/Miro DC30+: *
120* Zoran zr36067 PCI controller
121* Zoran zr36050 MJPEG codec
122* Zoran zr36016 Video Front End
123* Micronas vpx3225d/vpx3220a/vpx3216b TV decoder
124* Analog Devices adv7176 TV encoder
125Drivers to use: videodev, i2c-core, i2c-algo-bit,
126 videocodec, vpx3220/vpx3224, adv7175, zr36050, zr36015, zr36067
127Inputs/outputs: Composite, S-video and Internal
128Norms: PAL, SECAM (768x576 @ 25 fps), NTSC (640x480 @ 29.97 fps)
129Card number: 4
130
131Note: No module for the mse3000 is available yet
132Note: No module for the vpx3224 is available yet
133Note: use encoder=X or decoder=X for non-default i2c chips (see i2c-id.h)
134
135===========================
136
1371.1 What the TV decoder can do an what not
138
139The best know TV standards are NTSC/PAL/SECAM. but for decoding a frame that
140information is not enough. There are several formats of the TV standards.
Mauro Carvalho Chehab48773e62006-03-25 09:21:43 -0300141And not every TV decoder is able to handle every format. Also the every
142combination is supported by the driver. There are currently 11 different
143tv broadcast formats all aver the world.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144
Mauro Carvalho Chehab48773e62006-03-25 09:21:43 -0300145The CCIR defines parameters needed for broadcasting the signal.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146The CCIR has defined different standards: A,B,D,E,F,G,D,H,I,K,K1,L,M,N,...
147The CCIR says not much about about the colorsystem used !!!
148And talking about a colorsystem says not to much about how it is broadcast.
149
150The CCIR standards A,E,F are not used any more.
151
152When you speak about NTSC, you usually mean the standard: CCIR - M using
153the NTSC colorsystem which is used in the USA, Japan, Mexico, Canada
Mauro Carvalho Chehab48773e62006-03-25 09:21:43 -0300154and a few others.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155
156When you talk about PAL, you usually mean: CCIR - B/G using the PAL
Mauro Carvalho Chehab48773e62006-03-25 09:21:43 -0300157colorsystem which is used in many Countries.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158
Mauro Carvalho Chehab48773e62006-03-25 09:21:43 -0300159When you talk about SECAM, you mean: CCIR - L using the SECAM Colorsystem
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160which is used in France, and a few others.
161
162There the other version of SECAM, CCIR - D/K is used in Bulgaria, China,
Mauro Carvalho Chehab48773e62006-03-25 09:21:43 -0300163Slovakai, Hungary, Korea (Rep.), Poland, Rumania and a others.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164
Mauro Carvalho Chehab48773e62006-03-25 09:21:43 -0300165The CCIR - H uses the PAL colorsystem (sometimes SECAM) and is used in
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166Egypt, Libya, Sri Lanka, Syrain Arab. Rep.
167
168The CCIR - I uses the PAL colorsystem, and is used in Great Britain, Hong Kong,
169Ireland, Nigeria, South Africa.
170
171The CCIR - N uses the PAL colorsystem and PAL frame size but the NTSC framerate,
172and is used in Argentinia, Uruguay, an a few others
173
174We do not talk about how the audio is broadcast !
175
Mauro Carvalho Chehab48773e62006-03-25 09:21:43 -0300176A rather good sites about the TV standards are:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177http://www.sony.jp/ServiceArea/Voltage_map/
178http://info.electronicwerkstatt.de/bereiche/fernsehtechnik/frequenzen_und_normen/Fernsehnormen/
179and http://www.cabl.com/restaurant/channel.html
180
181Other weird things around: NTSC 4.43 is a modificated NTSC, which is mainly
182used in PAL VCR's that are able to play back NTSC. PAL 60 seems to be the same
Mauro Carvalho Chehab48773e62006-03-25 09:21:43 -0300183as NTSC 4.43 . The Datasheets also talk about NTSC 44, It seems as if it would
184be the same as NTSC 4.43.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185NTSC Combs seems to be a decoder mode where the decoder uses a comb filter
186to split coma and luma instead of a Delay line.
187
188But I did not defiantly find out what NTSC Comb is.
189
190Philips saa7111 TV decoder
Mauro Carvalho Chehab48773e62006-03-25 09:21:43 -0300191was introduced in 1997, is used in the BUZ and
192can handle: PAL B/G/H/I, PAL N, PAL M, NTSC M, NTSC N, NTSC 4.43 and SECAM
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193
194Philips saa7110a TV decoder
195was introduced in 1995, is used in the Pinnacle/Miro DC10(new), DC10+ and
Mauro Carvalho Chehab48773e62006-03-25 09:21:43 -0300196can handle: PAL B/G, NTSC M and SECAM
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197
198Philips saa7114 TV decoder
Mauro Carvalho Chehab48773e62006-03-25 09:21:43 -0300199was introduced in 2000, is used in the LML33R10 and
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200can handle: PAL B/G/D/H/I/N, PAL N, PAL M, NTSC M, NTSC 4.43 and SECAM
201
202Brooktree bt819 TV decoder
203was introduced in 1996, and is used in the LML33 and
204can handle: PAL B/D/G/H/I, NTSC M
205
206Micronas vpx3220a TV decoder
207was introduced in 1996, is used in the DC30 and DC30+ and
208can handle: PAL B/G/H/I, PAL N, PAL M, NTSC M, NTSC 44, PAL 60, SECAM,NTSC Comb
209
Martin Samuelssonfbe60da2006-04-27 10:17:00 -0300210Samsung ks0127 TV decoder
211is used in the AVS6EYES card and
212can handle: NTSC-M/N/44, PAL-M/N/B/G/H/I/D/K/L and SECAM
213
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214===========================
215
2161.2 What the TV encoder can do an what not
217
218The TV encoder are doing the "same" as the decoder, but in the oder direction.
219You feed them digital data and the generate a Composite or SVHS signal.
220For information about the colorsystems and TV norm take a look in the
221TV decoder section.
222
223Philips saa7185 TV Encoder
224was introduced in 1996, is used in the BUZ
225can generate: PAL B/G, NTSC M
226
227Brooktree bt856 TV Encoder
Mauro Carvalho Chehab48773e62006-03-25 09:21:43 -0300228was introduced in 1994, is used in the LML33
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229can generate: PAL B/D/G/H/I/N, PAL M, NTSC M, PAL-N (Argentina)
230
231Analog Devices adv7170 TV Encoder
232was introduced in 2000, is used in the LML300R10
233can generate: PAL B/D/G/H/I/N, PAL M, NTSC M, PAL 60
234
235Analog Devices adv7175 TV Encoder
236was introduced in 1996, is used in the DC10, DC10+, DC10 old, DC30, DC30+
237can generate: PAL B/D/G/H/I/N, PAL M, NTSC M
238
239ITT mse3000 TV encoder
240was introduced in 1991, is used in the DC10 old
241can generate: PAL , NTSC , SECAM
242
Martin Samuelssonfbe60da2006-04-27 10:17:00 -0300243Conexant bt866 TV encoder
244is used in AVS6EYES, and
245can generate: NTSC/PAL, PAL­M, PAL­N
246
Mauro Carvalho Chehab48773e62006-03-25 09:21:43 -0300247The adv717x, should be able to produce PAL N. But you find nothing PAL N
Tobias Klauserd533f672005-09-10 00:26:46 -0700248specific in the registers. Seem that you have to reuse a other standard
Mauro Carvalho Chehab48773e62006-03-25 09:21:43 -0300249to generate PAL N, maybe it would work if you use the PAL M settings.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250
251==========================
252
2532. How do I get this damn thing to work
254
255Load zr36067.o. If it can't autodetect your card, use the card=X insmod
256option with X being the card number as given in the previous section.
257To have more than one card, use card=X1[,X2[,X3,[X4[..]]]]
258
259To automate this, add the following to your /etc/modprobe.conf:
260
261options zr36067 card=X1[,X2[,X3[,X4[..]]]]
262alias char-major-81-0 zr36067
263
264One thing to keep in mind is that this doesn't load zr36067.o itself yet. It
265just automates loading. If you start using xawtv, the device won't load on
266some systems, since you're trying to load modules as a user, which is not
267allowed ("permission denied"). A quick workaround is to add 'Load "v4l"' to
268XF86Config-4 when you use X by default, or to run 'v4l-conf -c <device>' in
269one of your startup scripts (normally rc.local) if you don't use X. Both
270make sure that the modules are loaded on startup, under the root account.
271
272===========================
273
2743. What mainboard should I use (or why doesn't my card work)
275
276<insert lousy disclaimer here>. In short: good=SiS/Intel, bad=VIA.
277
278Experience tells us that people with a Buz, on average, have more problems
279than users with a DC10+/LML33. Also, it tells us that people owning a VIA-
280based mainboard (ktXXX, MVP3) have more problems than users with a mainboard
281based on a different chipset. Here's some notes from Andrew Stevens:
282--
283Here's my experience of using LML33 and Buz on various motherboards:
284
285VIA MVP3
286 Forget it. Pointless. Doesn't work.
Mauro Carvalho Chehab48773e62006-03-25 09:21:43 -0300287Intel 430FX (Pentium 200)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700288 LML33 perfect, Buz tolerable (3 or 4 frames dropped per movie)
289Intel 440BX (early stepping)
290 LML33 tolerable. Buz starting to get annoying (6-10 frames/hour)
291Intel 440BX (late stepping)
292 Buz tolerable, LML3 almost perfect (occasional single frame drops)
293SiS735
294 LML33 perfect, Buz tolerable.
295VIA KT133(*)
296 LML33 starting to get annoying, Buz poor enough that I have up.
297
298Both 440BX boards were dual CPU versions.
299--
300Bernhard Praschinger later added:
301--
302AMD 751
303 Buz perfect-tolerable
304AMD 760
305 Buz perfect-tolerable
306--
307In general, people on the user mailinglist won't give you much of a chance
308if you have a VIA-based motherboard. They may be cheap, but sometimes, you'd
309rather want to spend some more money on better boards. In general, VIA
310mainboard's IDE/PCI performance will also suck badly compared to others.
311You'll noticed the DC10+/DC30+ aren't mentioned anywhere in the overview.
312Basically, you can assume that if the Buz works, the LML33 will work too. If
313the LML33 works, the DC10+/DC30+ will work too. They're most tolerant to
314different mainboard chipsets from all of the supported cards.
315
316If you experience timeouts during capture, buy a better mainboard or lower
317the quality/buffersize during capture (see 'Concerning buffer sizes, quality,
318output size etc.'). If it hangs, there's little we can do as of now. Check
319your IRQs and make sure the card has its own interrupts.
320
321===========================
322
3234. Programming interface
324
325This driver conforms to video4linux and video4linux2, both can be used to
326use the driver. Since video4linux didn't provide adequate calls to fully
327use the cards' features, we've introduced several programming extensions,
328which are currently officially accepted in the 2.4.x branch of the kernel.
329These extensions are known as the v4l/mjpeg extensions. See zoran.h for
330details (structs/ioctls).
331
332Information - video4linux:
333http://roadrunner.swansea.linux.org.uk/v4lapi.shtml
334Documentation/video4linux/API.html
335/usr/include/linux/videodev.h
336
337Information - video4linux/mjpeg extensions:
338./zoran.h
339(also see below)
340
341Information - video4linux2:
342http://www.thedirks.org/v4l2/
343/usr/include/linux/videodev2.h
344http://www.bytesex.org/v4l/
345
346More information on the video4linux/mjpeg extensions, by Serguei
347Miridonovi and Rainer Johanni:
348--
349The ioctls for that interface are as follows:
350
351BUZIOC_G_PARAMS
352BUZIOC_S_PARAMS
353
354Get and set the parameters of the buz. The user should always do a
355BUZIOC_G_PARAMS (with a struct buz_params) to obtain the default
356settings, change what he likes and then make a BUZIOC_S_PARAMS call.
357
358BUZIOC_REQBUFS
359
360Before being able to capture/playback, the user has to request
361the buffers he is wanting to use. Fill the structure
362zoran_requestbuffers with the size (recommended: 256*1024) and
363the number (recommended 32 up to 256). There are no such restrictions
364as for the Video for Linux buffers, you should LEAVE SUFFICIENT
365MEMORY for your system however, else strange things will happen ....
366On return, the zoran_requestbuffers structure contains number and
367size of the actually allocated buffers.
368You should use these numbers for doing a mmap of the buffers
369into the user space.
370The BUZIOC_REQBUFS ioctl also makes it happen, that the next mmap
371maps the MJPEG buffer instead of the V4L buffers.
372
373BUZIOC_QBUF_CAPT
374BUZIOC_QBUF_PLAY
375
376Queue a buffer for capture or playback. The first call also starts
377streaming capture. When streaming capture is going on, you may
378only queue further buffers or issue syncs until streaming
379capture is switched off again with a argument of -1 to
380a BUZIOC_QBUF_CAPT/BUZIOC_QBUF_PLAY ioctl.
381
382BUZIOC_SYNC
383
384Issue this ioctl when all buffers are queued. This ioctl will
385block until the first buffer becomes free for saving its
386data to disk (after BUZIOC_QBUF_CAPT) or for reuse (after BUZIOC_QBUF_PLAY).
387
388BUZIOC_G_STATUS
389
390Get the status of the input lines (video source connected/norm).
391
392For programming example, please, look at lavrec.c and lavplay.c code in
393lavtools-1.2p2 package (URL: http://www.cicese.mx/~mirsev/DC10plus/)
394and the 'examples' directory in the original Buz driver distribution.
395
396Additional notes for software developers:
397
398 The driver returns maxwidth and maxheight parameters according to
399 the current TV standard (norm). Therefore, the software which
400 communicates with the driver and "asks" for these parameters should
401 first set the correct norm. Well, it seems logically correct: TV
402 standard is "more constant" for current country than geometry
403 settings of a variety of TV capture cards which may work in ITU or
404 square pixel format. Remember that users now can lock the norm to
405 avoid any ambiguity.
406--
407Please note that lavplay/lavrec are also included in the MJPEG-tools
408(http://mjpeg.sf.net/).
409
410===========================
411
4125. Applications
413
414Applications known to work with this driver:
415
416TV viewing:
417* xawtv
418* kwintv
419* probably any TV application that supports video4linux or video4linux2.
420
421MJPEG capture/playback:
422* mjpegtools/lavtools (or Linux Video Studio)
423* gstreamer
424* mplayer
425
426General raw capture:
427* xawtv
428* gstreamer
429* probably any application that supports video4linux or video4linux2
430
431Video editing:
432* Cinelerra
433* MainActor
434* mjpegtools (or Linux Video Studio)
435
436===========================
437
4386. Concerning buffer sizes, quality, output size etc.
439
440The zr36060 can do 1:2 JPEG compression. This is really the theoretical
441maximum that the chipset can reach. The driver can, however, limit compression
442to a maximum (size) of 1:4. The reason for this is that some cards (e.g. Buz)
443can't handle 1:2 compression without stopping capture after only a few minutes.
444With 1:4, it'll mostly work. If you have a Buz, use 'low_bitrate=1' to go into
4451:4 max. compression mode.
446
447100% JPEG quality is thus 1:2 compression in practice. So for a full PAL frame
448(size 720x576). The JPEG fields are stored in YUY2 format, so the size of the
449fields are 720x288x16/2 bits/field (2 fields/frame) = 207360 bytes/field x 2 =
450414720 bytes/frame (add some more bytes for headers and DHT (huffman)/DQT
451(quantization) tables, and you'll get to something like 512kB per frame for
4521:2 compression. For 1:4 compression, you'd have frames of half this size.
453
454Some additional explanation by Martin Samuelsson, which also explains the
455importance of buffer sizes:
456--
457> Hmm, I do not think it is really that way. With the current (downloaded
458> at 18:00 Monday) driver I get that output sizes for 10 sec:
459> -q 50 -b 128 : 24.283.332 Bytes
460> -q 50 -b 256 : 48.442.368
461> -q 25 -b 128 : 24.655.992
462> -q 25 -b 256 : 25.859.820
463
Mauro Carvalho Chehab48773e62006-03-25 09:21:43 -0300464I woke up, and can't go to sleep again. I'll kill some time explaining why
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465this doesn't look strange to me.
466
Mauro Carvalho Chehab48773e62006-03-25 09:21:43 -0300467Let's do some math using a width of 704 pixels. I'm not sure whether the Buz
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468actually use that number or not, but that's not too important right now.
469
Mauro Carvalho Chehab48773e62006-03-25 09:21:43 -0300470704x288 pixels, one field, is 202752 pixels. Divided by 64 pixels per block;
4713168 blocks per field. Each pixel consist of two bytes; 128 bytes per block;
4721024 bits per block. 100% in the new driver mean 1:2 compression; the maximum
473output becomes 512 bits per block. Actually 510, but 512 is simpler to use
Linus Torvalds1da177e2005-04-16 15:20:36 -0700474for calculations.
475
Mauro Carvalho Chehab48773e62006-03-25 09:21:43 -0300476Let's say that we specify d1q50. We thus want 256 bits per block; times 3168
477becomes 811008 bits; 101376 bytes per field. We're talking raw bits and bytes
478here, so we don't need to do any fancy corrections for bits-per-pixel or such
Linus Torvalds1da177e2005-04-16 15:20:36 -0700479things. 101376 bytes per field.
480
Mauro Carvalho Chehab48773e62006-03-25 09:21:43 -0300481d1 video contains two fields per frame. Those sum up to 202752 bytes per
Linus Torvalds1da177e2005-04-16 15:20:36 -0700482frame, and one of those frames goes into each buffer.
483
Mauro Carvalho Chehab48773e62006-03-25 09:21:43 -0300484But wait a second! -b128 gives 128kB buffers! It's not possible to cram
Linus Torvalds1da177e2005-04-16 15:20:36 -0700485202752 bytes of JPEG data into 128kB!
486
Mauro Carvalho Chehab48773e62006-03-25 09:21:43 -0300487This is what the driver notice and automatically compensate for in your
Linus Torvalds1da177e2005-04-16 15:20:36 -0700488examples. Let's do some math using this information:
489
Mauro Carvalho Chehab48773e62006-03-25 09:21:43 -0300490128kB is 131072 bytes. In this buffer, we want to store two fields, which
491leaves 65536 bytes for each field. Using 3168 blocks per field, we get
49220.68686868... available bytes per block; 165 bits. We can't allow the
493request for 256 bits per block when there's only 165 bits available! The -q50
494option is silently overridden, and the -b128 option takes precedence, leaving
Linus Torvalds1da177e2005-04-16 15:20:36 -0700495us with the equivalence of -q32.
496
Mauro Carvalho Chehab48773e62006-03-25 09:21:43 -0300497This gives us a data rate of 165 bits per block, which, times 3168, sums up
498to 65340 bytes per field, out of the allowed 65536. The current driver has
499another level of rate limiting; it won't accept -q values that fill more than
5006/8 of the specified buffers. (I'm not sure why. "Playing it safe" seem to be
501a safe bet. Personally, I think I would have lowered requested-bits-per-block
502by one, or something like that.) We can't use 165 bits per block, but have to
503lower it again, to 6/8 of the available buffer space: We end up with 124 bits
504per block, the equivalence of -q24. With 128kB buffers, you can't use greater
Linus Torvalds1da177e2005-04-16 15:20:36 -0700505than -q24 at -d1. (And PAL, and 704 pixels width...)
506
Mauro Carvalho Chehab48773e62006-03-25 09:21:43 -0300507The third example is limited to -q24 through the same process. The second
508example, using very similar calculations, is limited to -q48. The only
509example that actually grab at the specified -q value is the last one, which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700510is clearly visible, looking at the file size.
511--
512
513Conclusion: the quality of the resulting movie depends on buffer size, quality,
514whether or not you use 'low_bitrate=1' as insmod option for the zr36060.c
515module to do 1:4 instead of 1:2 compression, etc.
516
517If you experience timeouts, lowering the quality/buffersize or using
518'low_bitrate=1 as insmod option for zr36060.o might actually help, as is
519proven by the Buz.
520
521===========================
522
5237. It hangs/crashes/fails/whatevers! Help!
524
525Make sure that the card has its own interrupts (see /proc/interrupts), check
526the output of dmesg at high verbosity (load zr36067.o with debug=2,
527load all other modules with debug=1). Check that your mainboard is favorable
528(see question 2) and if not, test the card in another computer. Also see the
529notes given in question 3 and try lowering quality/buffersize/capturesize
530if recording fails after a period of time.
531
532If all this doesn't help, give a clear description of the problem including
533detailed hardware information (memory+brand, mainboard+chipset+brand, which
534MJPEG card, processor, other PCI cards that might be of interest), give the
535system PnP information (/proc/interrupts, /proc/dma, /proc/devices), and give
536the kernel version, driver version, glibc version, gcc version and any other
537information that might possibly be of interest. Also provide the dmesg output
538at high verbosity. See 'Contacting' on how to contact the developers.
539
540===========================
541
5428. Maintainers/Contacting
543
544The driver is currently maintained by Laurent Pinchart and Ronald Bultje
545(<laurent.pinchart@skynet.be> and <rbultje@ronald.bitfreak.net>). For bug
546reports or questions, please contact the mailinglist instead of the developers
547individually. For user questions (i.e. bug reports or how-to questions), send
548an email to <mjpeg-users@lists.sf.net>, for developers (i.e. if you want to
549help programming), send an email to <mjpeg-developer@lists.sf.net>. See
550http://www.sf.net/projects/mjpeg/ for subscription information.
551
552For bug reports, be sure to include all the information as described in
553the section 'It hangs/crashes/fails/whatevers! Help!'. Please make sure
554you're using the latest version (http://mjpeg.sf.net/driver-zoran/).
555
556Previous maintainers/developers of this driver include Serguei Miridonov
557<mirsev@cicese.mx>, Wolfgang Scherr <scherr@net4you.net>, Dave Perks
558<dperks@ibm.net> and Rainer Johanni <Rainer@Johanni.de>.
559
560===========================
561
5629. License
563
564This driver is distributed under the terms of the General Public License.
565
566 This program is free software; you can redistribute it and/or modify
567 it under the terms of the GNU General Public License as published by
568 the Free Software Foundation; either version 2 of the License, or
569 (at your option) any later version.
570
571 This program is distributed in the hope that it will be useful,
572 but WITHOUT ANY WARRANTY; without even the implied warranty of
573 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
574 GNU General Public License for more details.
575
576 You should have received a copy of the GNU General Public License
577 along with this program; if not, write to the Free Software
578 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
579
580See http://www.gnu.org/ for more information.