[FFmpeg-user] conversion dropping frames

[Carles Vila]

Hi all,
I'm converting a JPEG2000 image sequence to prores. The command works fine
but it reports dropped frames during the conversion. What could be the
cause?  Is there any way to avoid this by forcing a retry or something?
Strangely ffmpeg reports an 25fps rate for the image sequence (?) I had to
add -r 24 to make it the correct framerate. FYI, the image sequence is
being read from network and the prores written to local HD.

Thank you!


$ ffmpeg -i frm_%6d.j2c -c:v prores -profile:v 3 -r 24
/Volumes/VIDEO5/QHEV_R8.mov
ffmpeg version 2.4.2 Copyright (c) 2000-2014 the FFmpeg developers
  built on Oct 28 2014 17:39:46 with Apple LLVM version 5.1
(clang-503.0.40) (based on LLVM 3.4svn)
  configuration: --prefix=/usr/local/Cellar/ffmpeg/2.4.2 --enable-shared
--enable-pthreads --enable-gpl --enable-version3 --enable-nonfree
--enable-hardcoded-tables --enable-avresample --enable-vda --cc=clang
--host-cflags= --host-ldflags= --enable-libx264 --enable-libfaac
--enable-libmp3lame --enable-libxvid --enable-libfreetype
--enable-libtheora --enable-libvorbis --enable-libvpx --enable-librtmp
--enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libvo-aacenc
--enable-libass --enable-ffplay --enable-libspeex --enable-libschroedinger
--enable-libfdk-aac --enable-libopus --enable-frei0r --enable-libopenjpeg
--extra-cflags='-I/usr/local/Cellar/openjpeg/1.5.1_1/include/openjpeg-1.5 '
  libavutil      54.  7.100 / 54.  7.100
  libavcodec     56.  1.100 / 56.  1.100
  libavformat    56.  4.101 / 56.  4.101
  libavdevice    56.  0.100 / 56.  0.100
  libavfilter     5.  1.100 /  5.  1.100
  libavresample   2.  1.  0 /  2.  1.  0
  libswscale      3.  0.100 /  3.  0.100
  libswresample   1.  1.100 /  1.  1.100
  libpostproc    53.  0.100 / 53.  0.100
Input #0, image2, from 'frm_%6d.j2c':
  Duration: 00:14:58.16, start: 0.000000, bitrate: N/A
    Stream #0:0: Video: jpeg2000 (JPEG 2000 digital cinema 2K), xyz12le,
2048x858, 25 fps, 25 tbr, 25 tbn, 25 tbc
Output #0, mov, to '/Volumes/VIDEO5/QHEV_R8.mov':
  Metadata:
    encoder         : Lavf56.4.101
    Stream #0:0: Video: prores (apch) (apch / 0x68637061), yuv422p10le,
2048x858, q=2-31, 200 kb/s, 24 fps, 12288 tbn, 24 tbc
    Metadata:
      encoder         : Lavc56.1.100 prores
Stream mapping:
  Stream #0:0 -> #0:0 (jpeg2000 (native) -> prores (native))
Press [q] to stop, [?] for help
frame=13509 fps=8.9 q=0.0 size=15375123kB time=00:09:22.79
bitrate=223800.4kbits/s dup=0 *drop=561  *