Re: MPEG encoder API notes (Re: ANNOUNCE: ivtv alpha release)
Forgot that some encoders also support MPEG-1. And also most MPEG encoders do have a from of noise reduction, but this is very encoder specific. Gert system stream: - type: elementary stream(ES), packatised elementary stream(s) (PES) program stream(PS), transport stream(TS) (MPEG-1 systems stream ~ MPEG-2 program stream, TS not supported by MPEG-1 systems) - system bitrate - PS packet size (DVD: 2048 bytes, VCD: 2324 bytes) - TS video PID - TS audio PID - TS PCR PID - TS system information tables (PAT, PMT, CAT, NIT and SIT) audio: - type: MPEG, AC-3, LPCM - bitrate - sampling frequency (DVD: 48 Khz, VCD: 44.1 KHz) video: - noise reduction, parameters encoder specific? - picturesize (SIF, 1/2 D1, 2/3 D1, D1) and PAL/NTSC norm can be set through excisting V4L2 controls - MPEG video version: MPEG-1, MPEG-2 - GOP (Group Of Pictures) definition: - N: number of frames per GOP - M: distance between reference (I,P) frames - open/closed GOP - quantiser matrix: inter Q matrix (64 bytes) and intra Q matrix (64 bytes) - quantiser scale: linear or logarithmic - scanning: alternate or zigzag - bitrate mode: CBR (constant bitrate) or VBR (variable bitrate). - target video bitrate for CBR - target video bitrate for VBR - maximum video bitrate for VBR - min. quantiser value for VBR - max. quantiser value for VBR - adaptive quantisation value - return the number of bytes per GOP or bitrate for bitrate monitoring -- video4linux-list mailing list Unsubscribe mailto:[EMAIL PROTECTED]?subject=unsubscribe https://listman.redhat.com/mailman/listinfo/video4linux-list
Re: MPEG encoder API notes (Re: ANNOUNCE: ivtv alpha release)
On Fri, 7 Feb 2003, Gert Vervoort wrote: It is also very likely that not all of these settings are supported by other MPEG encoders or that other MPEG encoders have also other parameters available. In practice some parameters can also be fixed, depening on a type of system stream or picture size. I'm not real familiar with the MPEG specs either, but most of what you enumerated here (and your next message) looks supportable by the iTVC15. I don't remember any settings for the quantizer, but that may be a register/mmio level operation which I don't have docs for. Perhaps we use this as the baseline, and the driver can reply with an UNSUPPORTED message to any that it doesn't handle. For the properties that tend to be card specific (noise reduction), those can be handled by userspace tweak utilites. audio: - type: MPEG, AC-3, LPCM Layer I,II,III (iTVC15 does 1 2 but not 3) Our chip can support AC3, but the card hardware isn't wired to support it as far as I can tell. - bitrate - sampling frequency (DVD: 48 Khz, VCD: 44.1 KHz) 32KHz Trick Modes? (ff, rew) Copyright Inverse Telecine John -- video4linux-list mailing list Unsubscribe mailto:[EMAIL PROTECTED]?subject=unsubscribe https://listman.redhat.com/mailman/listinfo/video4linux-list
Re: MPEG encoder API notes (Re: ANNOUNCE: ivtv alpha release)
PlasmaJohn wrote: I'm not real familiar with the MPEG specs either, but most of what you enumerated here (and your next message) looks supportable by the iTVC15. I don't remember any settings for the quantizer, but that may be a register/mmio level operation which I don't have docs for. The qmin/qmax settings I mention are specific for the VBR bitrate control of the SAA6752. Also the adaptive quantisation is specific for this IC. Other encoder might or might not use these kinds parameters, but I'm sure they have a slightly different meaning then. The inter/intra quantiser matrices I mentioned are part of the MPEG video standard. The standard describes default matrices, but also custom matrices might be used. An encoder could implement fixed (default or custom) Q matrices or give make it programmable. Perhaps we use this as the baseline, and the driver can reply with an UNSUPPORTED message to any that it doesn't handle. For the properties that tend to be card specific (noise reduction), those can be handled by userspace tweak utilites. Proberbly a custom ioctl could be used. audio: - type: MPEG, AC-3, LPCM Layer I,II,III (iTVC15 does 1 2 but not 3) For SAA6752 the MPEG audio is fixed to MPEG1 layer 2. Our chip can support AC3, but the card hardware isn't wired to support it as far as I can tell. - bitrate - sampling frequency (DVD: 48 Khz, VCD: 44.1 KHz) 32KHz This also a valid value. (althoug not support by SAA6752, which is fixed to 48kHz). Trick Modes? (ff, rew) Trick modes are a decoder issue. Does iTVC15 also have a MPEG decoder? This raises a different topic, as my list was encoding specific. MPEG encoding and decoding are very different issues, so a MPEG decoder will probarbly using a completely different API from an MPEG encoder. There is a MPEG decoder API for the Stradis MPEG decoder card in V4L (ioctl: VIDIOCSWRITEMODE, VIDIOCSPLAYMODE), might be a starting point for a MPEG decoder API. Copyright This could also be set, I saw that SAA6752 has also a field original. Inverse Telecine As far as I know not supported by SAA6752, but this is very usefull setting for 60 Hz contries. Gert -- video4linux-list mailing list Unsubscribe mailto:[EMAIL PROTECTED]?subject=unsubscribe https://listman.redhat.com/mailman/listinfo/video4linux-list
Re: MPEG encoder API notes (Re: ANNOUNCE: ivtv alpha release)
Gert Vervoort writes: PlasmaJohn wrote: This also a valid value. (althoug not support by SAA6752, which is fixed to 48kHz). Trick Modes? (ff, rew) Trick modes are a decoder issue. Does iTVC15 also have a MPEG decoder? This raises a different topic, as my list was encoding specific. MPEG encoding and decoding are very different issues, so a MPEG decoder will probarbly using a completely different API from an MPEG encoder. There is a MPEG decoder API for the Stradis MPEG decoder card in V4L (ioctl: VIDIOCSWRITEMODE, VIDIOCSPLAYMODE), might be a starting point for a MPEG decoder API. Have a look at the DVB API for playback. There are two playback devices supported (more or less) by GPL drivers, namely the full featured DVB cards based on the Technotrend design and the margi dvd pcmcia card. There is also a driver for the em8400 chip, but it's not publicly available. I also started to write a wrapper for the em8300 driver, but did not have the time to finish it. Marcus -- /\ | Dr. Marcus O.C. Metzler| | ||---| | [EMAIL PROTECTED]| http://www.metzlerbros.de/| \/ -- video4linux-list mailing list Unsubscribe mailto:[EMAIL PROTECTED]?subject=unsubscribe https://listman.redhat.com/mailman/listinfo/video4linux-list
Re: MPEG encoder API notes (Re: ANNOUNCE: ivtv alpha release)
On Sat, 8 Feb 2003, Gert Vervoort wrote: Trick Modes? (ff, rew) Trick modes are a decoder issue. Does iTVC15 also have a MPEG decoder? Yes, it does, but the trick modes API call is in the encoder section not sure why. (BTW, the '16 is encode only) Gert John -- video4linux-list mailing list Unsubscribe mailto:[EMAIL PROTECTED]?subject=unsubscribe https://listman.redhat.com/mailman/listinfo/video4linux-list
Re: MPEG encoder API notes (Re: ANNOUNCE: ivtv alpha release)
On Sat, 8 Feb 2003, Marcus Metzler wrote: There is also a driver for the em8400 chip, but it's not publicly available. Will it be? I hear good things about the X-Card, particularly compared to the dxr3. While the combo encode/decode card is interesting I'd much prefer seperated functions (one capture machine, multiple playback remotes). Thanks, John -- video4linux-list mailing list Unsubscribe mailto:[EMAIL PROTECTED]?subject=unsubscribe https://listman.redhat.com/mailman/listinfo/video4linux-list
Re: MPEG encoder API notes (Re: ANNOUNCE: ivtv alpha release)
PlasmaJohn writes: On Sat, 8 Feb 2003, Marcus Metzler wrote: There is also a driver for the em8400 chip, but it's not publicly available. Will it be? I hear good things about the X-Card, particularly compared to the dxr3. While the combo encode/decode card is interesting I'd much prefer seperated functions (one capture machine, multiple playback remotes). Thanks, John You have to ask convergence (www.convergence.de) and they probably have to ask sigma designs. Considering sigmas problems with open source that may be a problem. They will probably point to their closed source user space drivers, which are not very efficient and not very stable, the last time I cecked. Marcus -- /\ | Dr. Marcus O.C. Metzler| | ||---| | [EMAIL PROTECTED]| http://www.metzlerbros.de/| \/ -- video4linux-list mailing list Unsubscribe mailto:[EMAIL PROTECTED]?subject=unsubscribe https://listman.redhat.com/mailman/listinfo/video4linux-list
RE: MPEG encoder API notes (Re: ANNOUNCE: ivtv alpha release)
] From: [EMAIL PROTECTED] ] [mailto:[EMAIL PROTECTED]] On Behalf Of Gert Vervoort ] Forgot that some encoders also support MPEG-1. ] And also most MPEG encoders do have a from of noise ] reduction, but this ] is very encoder specific. Don't leave out other encoding formats too. Here is a reference board from Sigma Designs. http://www.sigmadesigns.com/products/rhapsody.htm - MPEG-1, MPEG-2 MP@ML, MPEG-4 Advanced Simple Profile Level 5* video decoding (Sigma Designs EM8475) - MPEG-1, MPEG-2 MP@ML, MPEG-4 Simple Profile, Level 3 (extended to 720 x 480i or 720 x 576i resolution) video encoding (Vweb VW 2005) - DolbyR Digital, MPEG-1 Layers 1 and 2, MPEG-4 Low Complexity AAC, and CD-DA audio decoding (Sigma Designs EM8475) - MPEG-1 Layers 1, 2 and 3, MPEG-2 Layers 1 and 2, Dolby Digital 2.0 and AAC 2.0 audio encoding (Vweb VW 2005) (Haven't found any commercial products using this chip yet.) A chip from Cirrus Logic can encode in MPEG2 (and integrates seamlessly with the saa7134): http://www-test.cirrus.com/en/products/pro/detail/P951.html - Supports real-time MPEG-1, MPEG-2 MP@ML, SP@ML, and MP@LL - Support for constant/one-pass variable bit rate - IPB-pictures, CBR, or VBR to 15Mbps - I-pictures only to 30Mbps - Supports Transport, Program, and Elementary streams - Support for real time, 2-channel, encoding/decoding of digital audio of either Dolby Digital or MPEG audio (Layer I, II, and III - MP3) - 8-bit OSD support (2-b text, 2-b to 8-b graphics) - 8 MB memory for full D1 (720) NTSC/PAL pictures Commercially available in http://www.kworld.com.tw/products/pro2/kw-capure-version.htm Whatever interface is devised it needs to be extensible (for both audio and video). -Greg -- -- video4linux-list mailing list Unsubscribe mailto:[EMAIL PROTECTED]?subject=unsubscribe https://listman.redhat.com/mailman/listinfo/video4linux-list
MPEG encoder API notes (Re: ANNOUNCE: ivtv alpha release)
So if this is going to be done for V4L2, maybe we could start on this list. A good start for a parameter list would probably be the .par files for mpegenc. Below there is a list of parameters I wrote down a while ago, it was intended to be a start for a V4L2 MPEG encoder API. But, I never finished it. Most of the parameters are based on my experiences with the SAA6752 MPEG-2 encoder, so most of these parameters could also be found back in the datasheet of this IC (http://www.semiconductors.philips.com/pip/SAA6752HS_V101.html). I also added VCD related settings, although these are not supported by this encoder. It is also very likely that not all of these settings are supported by other MPEG encoders or that other MPEG encoders have also other parameters available. In practice some parameters can also be fixed, depening on a type of system stream or picture size. Gert system stream: - type: elementary stream(ES), packatised elementary stream(s) (PES) program stream(PS), transport stream(TS) - system bitrate - PS packet size (DVD: 2048 bytes, VCD: 2324 bytes) - TS video PID - TS audio PID - TS PCR PID - TS system information tables (PAT, PMT, CAT, NIT and SIT) audio: - type: MPEG, AC-3, LPCM - bitrate - sampling frequency (DVD: 48 Khz, VCD: 44.1 KHz) video: - picturesize (SIF, 1/2 D1, 2/3 D1, D1) and PAL/NTSC norm can be set through excisting V4L2 controls - GOP (Group Of Pictures) definition: - N: number of frames per GOP - M: distance between reference (I,P) frames - open/closed GOP - quantiser matrix: inter Q matrix (64 bytes) and intra Q matrix (64 bytes) - quantiser scale: linear or logarithmic - scanning: alternate or zigzag - bitrate mode: CBR (constant bitrate) or VBR (variable bitrate). - target video bitrate for CBR - target video bitrate for VBR - maximum video bitrate for VBR - min. quantiser value for VBR - max. quantiser value for VBR - adaptive quantisation value - return the number of bytes per GOP or bitrate for bitrate monitoring -- video4linux-list mailing list Unsubscribe mailto:[EMAIL PROTECTED]?subject=unsubscribe https://listman.redhat.com/mailman/listinfo/video4linux-list
