Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 |
Tobias Klauser | d533f67 | 2005-09-10 00:26:46 -0700 | [diff] [blame^] | 225 | specific in the registers. Seem that you have to reuse a other standard |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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. |