I've downloaded a couple of Google Tech Talks from Google Video. "file" reports
ISO Media, MPEG v4 system, version 1 mplayer and totem play these files without apparent issue. When I play them on my nifty new cell phone I get audio but no video. Files that do play on my cell phone are identified as ISO Media, MPEG v4 system, version 2 or ISO Media, MPEG v4 system, 3GPP so it seems that all that is required is to re-encode the video stream with the mpeg4v2 codec. RTFMing led me to the following attempt, with the result suggesting ffmpeg is having difficulty with the audio stream. $ ffmpeg -i ParadoxOfChoice.mp4 -f mp4 -vcodec msmpeg4v2 -acodec copy ParadoxOfChoicev2.mp4 FFmpeg version SVN-rUNKNOWN, Copyright (c) 2000-2007 Fabrice Bellard, et al. configuration: --enable-gpl --enable-pp --enable-swscaler --enable-pthreads --enable-libvorbis --enable-libtheora --enable-libogg --enable-libgsm --enable-dc1394 --disable-debug --enable-shared --prefix=/usr libavutil version: 1d.49.3.0 libavcodec version: 1d.51.38.0 libavformat version: 1d.51.10.0 built on Jun 3 2007 20:59:25, gcc: 4.1.3 20070528 (prerelease) (Ubuntu 4.1.2-9ubuntu2) Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'ParadoxOfChoice.mp4': Duration: 01:04:11.2, start: 0.000000, bitrate: 449 kb/s Stream #0.0(und): Video: h264, yuv420p, 320x240, 29.97 fps(r) Stream #0.1(und): Audio: mp4a / 0x6134706D, 44100 Hz, stereo Output #0, mp4, to 'ParadoxOfChoicev2.mp4': Stream #0.0: Video: msmpeg4v2, yuv420p, 320x240, q=2-31, 200 kb/s, 29.97 fps(c) Stream #0.1: Audio: mp4a / 0x6134706D, 44100 Hz, stereo Stream mapping: Stream #0.0 -> #0.0 Stream #0.1 -> #0.1 [mp4 @ 0xb7eec5d0]Warning, using MS style video codec tag, the file may be unplayable! [mp4 @ 0xb7eec5d0]track 1: codec frame size is not set Could not write header for output file #0 (incorrect codec parameters ?) I am completely devoid of clue in these matters -- would someone more clueful be able to suggest an approach? Thanks, Roy.
