Re: [Mjpeg-users] 1.9.0-RC3 mpeg2enc - extensive rate control tests, possible issue?
Hallo > I did extensive tests with 1.9.0-RC3, regarding the average and maximum > bit rate, and the results are intriguing. It seems like the bit rate is > too high. I have encountered that problem too. I have written Andrew a mail about the problem. I have a 400 frames short sample here where the bitrate overshot happens. That should help to find the problem. Till I get a answer from Andrew the final release will wait for soure. > Source is a cheap new DV camcorder, NTSC 16:9. I've a bunch of DV files > that I transcode with different parameters, the numbers below are the > average and maximum bit rate for each file, as reported by mplex when > multiplexing the video and the audio tracks. Ok, so every line is more or less a different video. > mpeg2enc -v 0 -I 1 -f 8 -b 8000 -F 4 -n n -a 3 -o > "va-2007.12.09_16-55-18.m2v" -c -q 8 -4 1 -2 1 -s -D 10 -K kvcd -R 2 -M 2 [...a lot of data...] > It seems like it's overshooting a bit. E.g., with -q 7 -K default the > max is as high as 1, even though I'm using -b 8000 > The only combination that's remotely acceptable is -q 8 -K tmpgenc, but > even then the third file from the bottom gets up to 9200k bitrate. So you "only" have a bitrate overshot, but mplex multiplexes the files without a problem ? The sample I have mplex puts out a warning ( data will arrive too late) and breaks after several such warning messages. > I can provide a sample of one of the DV input files, but only by request > and only to the developers - I won't post the URL to the mailing list > because even a short sample can be pretty big. 400 frames about 50MB ;) auf hoffentlich bald, Berni the Chaos of Woodquarter Email: [EMAIL PROTECTED] www: http://www.lysator.liu.se/~gz/bernhard - SF.Net email is sponsored by: Check out the new SourceForge.net Marketplace. It's the best place to buy or sell services for just about anything Open Source. http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace ___ Mjpeg-users mailing list Mjpeg-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mjpeg-users
Re: [Mjpeg-users] 1.9.0-RC3 mpeg2enc - extensive rate control tests, possible issue?
Bernhard Praschinger wrote: > >> Source is a cheap new DV camcorder, NTSC 16:9. I've a bunch of DV files >> that I transcode with different parameters, the numbers below are the >> average and maximum bit rate for each file, as reported by mplex when >> multiplexing the video and the audio tracks. > Ok, so every line is more or less a different video. Yes. http://florin.myip.org/soft/conv-dvd/ If you look at the "grab" script, dvgrab is configured to start a new file whenever it encounters a scene change in the DV stream (whenever I paused or stopped the camcorder). So a DV tape is saved as a bunch of .avi files, each file being a different scene. Sometimes I edit a file or two with Kino, then mass-transcode and author the whole thing into a single-title, multiple-chapters, no-menus DVD. > So you "only" have a bitrate overshot, but mplex multiplexes the files > without a problem ? The sample I have mplex puts out a warning ( data > will arrive too late) and breaks after several such warning messages. The parameters I'm using are: mplex -f 8 -S 4400 $out.m2v $out.ac3 -o $out.vob mplex appears to not care about what I define as "too high bit rate". The target format is DVD, and there's a limit to the total bitrate of all video + audio channels. What I'm worried about is that due to the rate control issues, the DVD will exceed that limit. I've had enough problems with crappy DVD players and I want to avoid that if possible. After all, the reason why I've been using mjpegtools and not ffmpeg to generate the MPEG2 tracks for quite a few years now is rate control. Well, last time I checked the image quality was better too, so I'd like to keep using mpeg2enc for all the MPEG2 encoding. -- Florin Andrei http://florin.myip.org/ - SF.Net email is sponsored by: Check out the new SourceForge.net Marketplace. It's the best place to buy or sell services for just about anything Open Source. http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace ___ Mjpeg-users mailing list Mjpeg-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mjpeg-users
