[FFmpeg-user] FLV --> MP4 Conversion Audio/Video Out of Sync

[Leo Papadopoulos]

Dear Group:

With all your kind help I was able to convert my FLV(Speex+h264) to
MP4(AAC+h264) and the file plays on all my devices. However I get the
following errors and audio plays 1 second later than the video.

I have tried to use the -itsoffset flag but it does not seem to do
anything. Is itsoffset the path I should take? Or is my problem related to
the "PTS < DTS invalid clipping" messages below?

Leo P.


The command with the full output is below:

ffmpeg -i telecomcto.flv -c:v copy -c:a aac -strict -2 -b:a 64k -ar 44100
-ac 1 telecomctotest.mp4
ffmpeg version N-47994-ga1d1433 Copyright (c) 2000-2012 the FFmpeg
developers
  built on Dec 19 2012 15:40:59 with gcc 4.1.2 (GCC) 20080704 (Red Hat
4.1.2-52)
  configuration: --enable-gpl --enable-libmp3lame --enable-libvorbis
--enable-libvpx --enable-libx264 --enable-libspeex
  libavutil      52. 12.100 / 52. 12.100
  libavcodec     54. 80.100 / 54. 80.100
  libavformat    54. 49.102 / 54. 49.102
  libavdevice    54.  3.102 / 54.  3.102
  libavfilter     3. 28.102 /  3. 28.102
  libswscale      2.  1.103 /  2.  1.103
  libswresample   0. 17.102 /  0. 17.102
  libpostproc    52.  2.100 / 52.  2.100
Input #0, flv, from 'telecomcto.flv':
  Metadata:
    creationdate    : Wed Dec 19 10:49:09
  Duration: 00:00:12.33, start: 0.000000, bitrate: 673 kb/s
    Stream #0:0: Video: h264 (Baseline), yuv420p, 640x480 [SAR 1:1 DAR
4:3], 30 tbr, 1k tbn, 60 tbc
    Stream #0:1: Audio: speex, 16000 Hz, mono, s16
File 'telecomctotest.mp4' already exists. Overwrite ? [y/N] y
Output #0, mp4, to 'telecomctotest.mp4':
  Metadata:
    creationdate    : Wed Dec 19 10:49:09
    encoder         : Lavf54.49.102
    Stream #0:0: Video: h264 ([33][0][0][0] / 0x0021), yuv420p, 640x480
[SAR 1:1 DAR 4:3], q=2-31, 16k tbn, 1k tbc
    Stream #0:1: Audio: aac ([64][0][0][0] / 0x0040), 44100 Hz, mono, fltp,
64 kb/s
Stream mapping:
  Stream #0:0 -> #0:0 (copy)
  Stream #0:1 -> #0:1 (libspeex -> aac)
Press [q] to stop, [?] for help
[mp4 @ 0x1986fa0] st:0 PTS: 16176 DTS: 16176 < 16177 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 21568 DTS: 21568 < 21569 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 31040 DTS: 31040 < 31041 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 47072 DTS: 47072 < 47073 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 47072 DTS: 47072 < 47074 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 54416 DTS: 54416 < 54417 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 57632 DTS: 57632 < 57633 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 60032 DTS: 60032 < 60033 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 62128 DTS: 62128 < 62129 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 62128 DTS: 62128 < 62130 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 66368 DTS: 66368 < 66369 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 70432 DTS: 70432 < 70433 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 73856 DTS: 73856 < 73857 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 75856 DTS: 75856 < 75857 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 77872 DTS: 77872 < 77873 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 77872 DTS: 77872 < 77874 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 80016 DTS: 80016 < 80017 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 84272 DTS: 84272 < 84273 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 88816 DTS: 88816 < 88817 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 92896 DTS: 92896 < 92897 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 94976 DTS: 94976 < 94977 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 94976 DTS: 94976 < 94978 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 99376 DTS: 99376 < 99377 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 103456 DTS: 103456 < 103457 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 108944 DTS: 108944 < 108945 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 111280 DTS: 111280 < 111281 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 117552 DTS: 117552 < 117553 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 119600 DTS: 119600 < 119601 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 127072 DTS: 127072 < 127073 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 127072 DTS: 127072 < 127074 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 134528 DTS: 134528 < 134529 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 139824 DTS: 139824 < 139825 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 143184 DTS: 143184 < 143185 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 143184 DTS: 143184 < 143186 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 158736 DTS: 158736 < 158737 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 164480 DTS: 164480 < 164481 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 167360 DTS: 167360 < 167361 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 170784 DTS: 170784 < 170785 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 173856 DTS: 173856 < 173857 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 173856 DTS: 173856 < 173858 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 179488 DTS: 179488 < 179489 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 182576 DTS: 182576 < 182577 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 188944 DTS: 188944 < 188945 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 190976 DTS: 190976 < 190977 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 193088 DTS: 193088 < 193089 invalid, clipping
[mp4 @ 0x1986fa0] st:0 PTS: 197344 DTS: 197344 < 197345 invalid, clipping
frame=  184 fps=0.0 q=-1.0 Lsize=    1036kB time=00:00:12.46 bitrate=
680.4kbits/s
video:935kB audio:92kB subtitle:0 global headers:0kB muxing overhead
0.834750%