In 49d839d5.6020...@utanet.at, Bernhard Praschinger <shadowl...@utanet.at> wrote:
> So you try to rencode the video. > Can you please post the mpeg format, resolution and aspect ration the > source has. And the output format you want. The source video was 512x480, 29.97 Hz. 4:3 aspect ratio (captured from TV using a Hauppage card). It was what I think would be called an MPEG system stream. By the time I dropped it into the YUV file it had been converted to 352x480. I am trying to create an MPEG transport stream that compiles with the Cable Labs VOD 1.1 encoding spec. Unfortunately all I could find on-line is the 2.0 spec at http://www.cablelabs.com/specifications/MD-SP-VOD-CEP2.0-I02-070105.pdf which does not have identical limitations on the video rate. Roughly speaking I need IBBP video, <=3.18MBit/s, 15 frame GOPs, sequence header per GOP. The stuff that comes from commercial hardware encoders also includes sequence_extension and picture_coding_extension packets, but I do not think those are actually required. mpeg2enc is just a small piece of the equation. There are no free software tools that can create an MPEG transport stream that isn't utter garbage (and finding a commercial one that works well enough for VOD is something of a chore too). > > > mpeg2enc -a 2 -b 3180 -g 15 -G 15 -s -R 2 \ > > /homes4/thoth/drinky-crow/x.yuv \ > > -o /homes4/thoth/drinky-crow/x.m2v > I hope you know that you generate a fixed bitrate MPEG1 with a aspect > ratio of 4:3 and a fixed gop size. That's what I asked it to do, but it did not perform as advertised (with respect to the bit rate). > Can you try to encode without the -R 2 option and see what happens. > I haven't encoded a MPEG1 with that kind of parameters for a long time. That gives me an IP* stream which does not comply with section 4.8 of MD-SP-VOD-CEP-I01-040107 (CabLabs Video-On-Demand Content Encoding Profiles Specification). More importantly, the bit rate is still way wrong. Based on the file size I think it's doing around 9Mbit/s. The aspect_ratio_information is also still wrong (12 instead of 2). > > Both files play in mplayer, but the .m2v doesn't have the correct aspect > > ratio (-a 2 isn't being honored, and the > > sequence_header.aspect_ratio_information contains a 12 instead). ... > Does the yuv file look correct when you play it back with lavplay (cat > x.yuv | yuvplay) ? It plays as well with yuvplay as it did with mplayer. It looks fine. ------------------------------------------------------------------------------ This SF.net email is sponsored by: High Quality Requirements in a Collaborative Environment. Download a free trial of Rational Requirements Composer Now! http://p.sf.net/sfu/www-ibm-com _______________________________________________ Mjpeg-users mailing list Mjpeg-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mjpeg-users
