[FFmpeg-user] Output file to long

[Cecil Westerhof]

I use the following command:
ffmpeg
        -y
        -i original/violin-allemande.mp3 -t 215
        -ar 44100
        violin-allemande.mp3

I would expect to get a file of 2:35 long, but it is 2:39. This is the
length of the input file.
What is going wrong here?

The output from the command is:
    ffmpeg version 2.1.1 Copyright (c) 2000-2013 the FFmpeg developers
  built on Dec 17 2013 19:47:47 with gcc 4.7 (SUSE Linux)
  configuration: --shlibdir=/usr/lib64 --prefix=/usr --mandir=/usr/share/man --libdir=/usr/lib64 --enable-shared --disable-static --enable-debug --disable-stripping --extra-cflags='-fmessage-length=0 -O2 -Wall -D_FORTIFY_SOURCE=2 -fstack-protector -funwind-tables -fasynchronous-unwind-tables -g -fPIC -I/usr/include/gsm' --enable-gpl --enable-x11grab --enable-version3 --enable-pthreads --enable-avfilter --enable-libpulse --enable-libvpx --enable-libopus --enable-libass --enable-libmp3lame --enable-libvorbis --enable-libtheora --enable-libspeex --enable-libxvid --enable-libx264 --enable-libschroedinger --enable-libgsm --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-postproc --enable-libdc1394 --enable-librtmp --enable-libfreetype --enable-avresample --enable-libtwolame --enable-libvo-aacenc --enable-gnutls
  libavutil      52. 48.101 / 52. 48.101
  libavcodec     55. 39.101 / 55. 39.101
  libavformat    55. 19.104 / 55. 19.104
  libavdevice    55.  5.100 / 55.  5.100
  libavfilter     3. 90.100 /  3. 90.100
  libavresample   1.  1.  0 /  1.  1.  0
  libswscale      2.  5.101 /  2.  5.101
  libswresample   0. 17.104 /  0. 17.104
  libpostproc    52.  3.100 / 52.  3.100
[mp3 @ 0x1b4d8c0] Estimating duration from bitrate, this may be inaccurate
Input #0, mp3, from 'original/violin-allemande.mp3':
  Metadata:
    artist          : J. S. Bach
    genre           : Baroque
    title           : Allemande
    date            : 2013-06-26 11:16
  Duration: 00:02:39.17, start: 0.000000, bitrate: 255 kb/s
    Stream #0:0: Audio: mp3, 44100 Hz, stereo, s16p, 256 kb/s
Output #0, mp3, to 'violin-allemande.mp3':
  Metadata:
    TPE1            : J. S. Bach
    TCON            : Baroque
    TIT2            : Allemande
    TDRL            : 2013-06-26 11:16
    TSSE            : Lavf55.19.104
    Stream #0:0: Audio: mp3 (libmp3lame), 44100 Hz, stereo, s16p
Stream mapping:
  Stream #0:0 -> #0:0 (mp3 -> libmp3lame)
Press [q] to stop, [?] for help
size=     297kB time=00:00:18.96 bitrate= 128.3kbits/s    
size=     604kB time=00:00:38.63 bitrate= 128.1kbits/s    
size=     912kB time=00:00:58.33 bitrate= 128.1kbits/s    
size=    1218kB time=00:01:17.92 bitrate= 128.1kbits/s    
size=    1528kB time=00:01:37.75 bitrate= 128.1kbits/s    
size=    1839kB time=00:01:57.65 bitrate= 128.0kbits/s    
size=    2148kB time=00:02:17.43 bitrate= 128.0kbits/s    
size=    2464kB time=00:02:37.67 bitrate= 128.0kbits/s    
size=    2487kB time=00:02:39.11 bitrate= 128.0kbits/s    
video:0kB audio:2487kB subtitle:0 global headers:0kB muxing overhead 0.012450%

-- 
Cecil Westerhof
Senior Software Engineer
LinkedIn: http://www.linkedin.com/in/cecilwesterhof