New submission from gialloporpora <[email protected]>: Using FFmpeg to extract an audio track from youtube video like m4a file sound very nasty. The problem seems to be a problem of ffmpeg to create the m4a container, this is the comment of the fb2k developer: http://www.hydrogenaudio.org/forums/index.php?showtopic=84177
« This file was created using some kind of broken software and cannot be played correctly due to nonsensical seeking / frame duration information present. Other software that renders this correctly probably ignores the bad information at cost of inaccurate seeking. » To reproduce the problem you need to play the file (attached) with Foobar2000: http://www.foobar2000.org/download Now I'll report detailed info to reproduce the problem. Code used to extract the audio track from youtube video (flv or mp4 file with audio track encoded as aac) ffmpeg -i input.flv -acodec copy -vn file.m4a Result: http://dl.dropbox.com/u/4400966/seems_so_long_ago_nancy.m4a Result: Playing the file with foobar2000 is very nasty, no problem if I use other player. Extracting only the audio stream as aac file it works nicely: ffmpeg -i input.flv -acodec copy -vn output.aac Result: http://dl.dropbox.com/u/4400966/seems_so_long_ago_nancy.aac When I include the aac file in the m4a container the resulting m4a sound verty nasty in foobar2000. In the foobar forum have suggested me to use mp4box (a file contained in the GPAC project, it is opensource, I don't know if this could be used to fix the problem in ffmpeg) to add the audio stream to m4a container, and it works. Link to GPAC project: http://gpac.sourceforge.net/ I have used this version of ffmpeg (on Windows XP) C:\Documents and Settings\sandro> FFmpeg version SVN-r25107-Sherpya Attachment (I have put it to my dropbox account, no advertising to download them, if you wish that I upload it on your FTP server tell me) FLV: http://dl.dropbox.com/u/4400966/seems_so_long_ago_nancy.flv (video download from Youtube) M4A: http://dl.dropbox.com/u/4400966/seems_so_long_ago_nancy.m4a (bad file) AAC: http://dl.dropbox.com/u/4400966/seems_so_long_ago_nancy.aac (good) If you need more info tell me and I'll try to report it ---------- messages: 12238 priority: normal status: new substatus: new title: Nonsensical seeking / frame duration information creating m4a container type: bug ________________________________________________ FFmpeg issue tracker <[email protected]> <https://roundup.ffmpeg.org/issue2293> ________________________________________________
