[FFmpeg-user] ffmpeg mp3 output seems to be missing metadata

[Philipp Hagemeister]

I'm trying to convert an flv file to an mp3 one. This works, but seems
to be missing some kind of metadata:

$ file --version
file-5.09
magic file from /etc/magic:/usr/share/misc/magic
$ file out.mp3
out.mp3: Audio file with ID3 version 2.4.0, contains: , 44.1 kHz, Stereo

file correctly recognizes other audio files:
$ file ref.mp3
ref.mp3: Audio file with ID3 version 2.4.0, contains: MPEG ADTS, layer
III, v2,  64 kbps, 22.05 kHz, JntStereo


The command line I used to create out.mp3 is:

$ ffmpeg -i src.flv -acodec libmp3lame -f mp3 -ab 64k -y out.mp3
ffmpeg version 0.9, Copyright (c) 2000-2011 the FFmpeg developers
  built on Dec 29 2011 17:22:32 with gcc 4.6.2
  configuration: --prefix=/usr --extra-cflags='-Wall -g ' --cc='ccache
cc' --enable-shared --enable-libmp3lame --enable-gpl --enable-nonfree
--enable-libdirac --disable-decoder=libdirac --enable-libvorbis
--enable-pthreads --enable-libfaac --enable-libxvid --enable-postproc
--enable-x11grab --enable-libgsm --enable-libtheora
--enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libx264
--enable-libspeex --enable-nonfree --disable-stripping
--enable-libschroedinger --disable-encoder=libschroedinger
--enable-version3 --enable-libopenjpeg --enable-libvpx --enable-librtmp
--enable-avfilter --enable-frei0r --enable-libopencv
--enable-libfreetype --enable-libvo-aacenc --disable-decoder=amrnb
--enable-libvo-amrwbenc --enable-libaacplus
--libdir=/usr/lib/x86_64-linux-gnu --disable-vda --enable-libdc1394
--disable-altivec --disable-armv5te --disable-armv6 --disable-vis
--shlibdir=/usr/lib/x86_64-linux-gnu
  libavutil    51. 32. 0 / 51. 32. 0
  libavcodec   53. 42. 0 / 53. 42. 0
  libavformat  53. 24. 0 / 53. 24. 0
  libavdevice  53.  4. 0 / 53.  4. 0
  libavfilter   2. 53. 0 /  2. 53. 0
  libswscale    2.  1. 0 /  2.  1. 0
  libpostproc  51.  2. 0 / 51.  2. 0

Seems stream 0 codec frame rate differs from container frame rate: 59.83
(29917/500) -> 29.92 (359/12)
Input #0, flv, from 'src.flv':
  Metadata:
    starttime       : 0
    totalduration   : 3434
    totaldatarate   : 538
    bytelength      : 230852447
    canseekontime   : true
    sourcedata      : BADC21083HH1325457353220183
    purl            :
    pmsg            :
  Duration: 00:57:13.87, start: 0.000000, bitrate: 537 kb/s
    Stream #0:0: Video: h264 (Main), yuv420p, 640x360, 410 kb/s, 29.92
tbr, 1k tbn, 59.83 tbc
    Stream #0:1: Audio: aac, 44100 Hz, stereo, s16, 131 kb/s
Output #0, mp3, to 'out.mp3':
  Metadata:
    starttime       : 0
    totalduration   : 3434
    totaldatarate   : 538
    bytelength      : 230852447
    canseekontime   : true
    sourcedata      : BADC21083HH1325457353220183
    purl            :
    pmsg            :
    TSSE            : Lavf53.24.0
    Stream #0:0: Audio: mp3, 44100 Hz, stereo, s16, 64 kb/s
Stream mapping:
  Stream #0:1 -> #0:0 (aac -> libmp3lame)



How can I embed the metadata that is missing in out.mp3, but present in
ref.mp3?

- Philipp

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 198 bytes
Desc: OpenPGP digital signature
URL: <http://ffmpeg.org/pipermail/ffmpeg-user/attachments/20120105/a8e51f2d/attachment.asc>