Maybe try demuxing it with MP4Box, resize with FFmpeg, then remux with MP4Box? http://gpac.wp.mines-telecom.fr/downloads/gpac-nightly-builds/
On Fri, Feb 6, 2015 at 10:37 AM, Petr Tresnak <[email protected]> wrote: > Hi all, > I downscale the following 4k to 1080 using ffmpeg -i 4k.mp4 -vf > scale=1920:1080 -c:v libx264 -preset fast -crf 18 -c:a copy output.mp4" > > Duration: 00:00:10.56, start: 0.080000, bitrate: 95904 kb/ > Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuvj420p(pc, > bt709), 3840x2160 [SAR 1:1 DAR 16:9], 95655 kb/s, 25 fps > Stream #0:1(und): Audio: aac (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, > 124 kb/s (default) > > But there is a problem with proper copy of audio track: > > [mp4 @ 05e30860] track 1: codec frame size is not set > [mp4 @ 05e30860] Packet with invalid duration -1024 in stream 1 > > In trans-coded video file there is a small difference in audio afterwards > (AAC vs AAC LC, bitrate 124 vs 125): > Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, > fltp, 125 kb/s (default) > > Can you help how to force ffmpeg to copy audio track? > Thanks > Peter > > _______________________________________________ > ffmpeg-user mailing list > [email protected] > http://ffmpeg.org/mailman/listinfo/ffmpeg-user > _______________________________________________ ffmpeg-user mailing list [email protected] http://ffmpeg.org/mailman/listinfo/ffmpeg-user
