bvrulez wrote: > How can I analyse the file to know what exactly was written to it? > Thanks!
Depends on your background. I'm OK with decoding raw data so i used hexdump as I knew MP3 headers & IDV3.* are relatively simple, well documented (https://id3.org/id3v2.3.0#ID3v2_overview) and it was quicker than trying to find a tool. You could try ffmpeg/ffplay with loglevel of trace (e.g. ffplay -v trace filename.mp3) . It can produce output shown below for the original problem file "New Psycho". The Flags show 0x40 as the "extended header" (look at id3 linked page) Code: -------------------- [mp3 @ 0x7f57c0000bc0] Format mp3 probed with size=32768 and score=51 id3v2 ver:4 flags:40 len:13993 [mp3 @ 0x7f57c0000bc0] Skipping 0 bytes of junk at 14003. [mp3 @ 0x7f57c0000bc0] Before avformat_find_stream_info() pos: 14003 bytes read:32768 seeks:0 nb_streams:2 [mjpeg @ 0x7f57c00084c0] marker=d8 avail_size_in_buf=13799 [mjpeg @ 0x7f57c00084c0] marker parser used 0 bytes (0 bits) [mjpeg @ 0x7f57c00084c0] marker=e0 avail_size_in_buf=13797 . . . [mjpeg @ 0x7f57c00084c0] decode frame unused 0 bytes [mp3 @ 0x7f57c0000bc0] All info found [mp3 @ 0x7f57c0000bc0] Estimating duration from bitrate, this may be inaccurate [mp3 @ 0x7f57c0000bc0] stream 0: start_time: 0.000 duration: 306.725 [mp3 @ 0x7f57c0000bc0] stream 1: start_time: -102481911520608.625 duration: 306.725 [mp3 @ 0x7f57c0000bc0] format: start_time: 0.000 duration: 306.725 bitrate=192 kb/s [mp3 @ 0x7f57c0000bc0] After avformat_find_stream_info() pos: 43699 bytes read:65536 seeks:0 frames:51 Input #0, mp3, from '2008+03+22+05+New+Psycho.mp3': Metadata: encoder : MP3FS title : 2008 03 22 05 New Psycho artist : phaze album_artist : phaze album : Proberaum genre : Rock TLEN : 306689 Duration: 00:05:06.73, start: 0.000000, bitrate: 192 kb/s Stream #0:0, 50, 1/14112000: Audio: mp3, 48000 Hz, stereo, fltp, 192 kb/s Stream #0:1, 1, 1/90000: Video: mjpeg (Baseline), 1 reference frame, yuvj420p(pc, bt470bg/unknown/unknown, center), 300x300 [SAR 1:1 DAR 1:1], 0/1, 90k tbr, 90k tbn, 90k tbc (attached pic) Metadata: title : cover.jpg comment : Cover (front) . . . -------------------- For other formats where documentation is hard to find and/or uses more intricate encoding (e.g. MPEG4) - a existing tool ------------------------------------------------------------------------ bpa's Profile: http://forums.slimdevices.com/member.php?userid=1806 View this thread: http://forums.slimdevices.com/showthread.php?t=115010 _______________________________________________ discuss mailing list [email protected] http://lists.slimdevices.com/mailman/listinfo/discuss
