folks, i had considerable pain creating foolproof dvd material. cinelerra offers rendering to yuv4mpeg pipe in either of two ways, through mpeg2enc and mplex, or through ffmpeg and again ffmpeg.
in both cases, video and audio are rendered separately and then multiplexed together on the shell command line. however, in both ways i always kept producing horrific erroneus results. 1. mpeg2enc was good in some cases and bad in others. one of my movies kept systematically pausing for short moments (two or three frames duration) every few seconds. not professional. admittedly, it only happened when played on a commercial dvd player through an old tv set, while on the computer it ran smooth. however it always halted in the same places, even when burned slow. tweaking the quantization parameter either reduced the number of halts but with too much loss of image quality (it looked really blocky), or otherwise improved quality but also increased the number of errors. 2. ffmpeg renders interlaced footage in the wrong field order. so when played back on cheap dvd players, any motion looks horribly jerky. (although admittedly one new player somehow managed to play smooth.) cinelerra's preset default ffmpeg options come in two variants. one does not account at all for interlacing and produces wrong field order. the other crashes with an error. so here comes the solution. the second variant suggested in the render dialog looks like follows: "ffmpeg -f yuv4mpegpipe -i - -y -target dvd -ilme -ildct -hq -f mpeg2video %" the "-ilme -ildct" part is for interlacing, but is erroneous, thus the crash. i changed this into the following and got a working stream: "ffmpeg -f yuv4mpegpipe -i - -y -target dvd -flags +ilme+ildct %" (still with error messages about faulty headers or so. but it works.) the resulting .m2v can be further processed together with the .ac3 audio with the following shell command, producing a dvd-compatible mpeg stream: $ ffmpeg -i your-movie.ac3 -i your-movie.m2v -target dvd \ -flags +ilme+ildct your-movie.mpg that's it. check it out. maybe someone knows how to change the preset pipe options accordingly? and maybe someone else knows how to put this information into the manual? :-) cheers georg -- dr.k.g.hooss schoepfung & wandel wissenschaftliche medienberatung breite strasse 6-8, d-23617 luebeck www.schoepfung-und-wandel.de
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