[FFmpeg-trac] #8726(undetermined:new): Inaccurate length display / detection (m4a files)

[FFmpeg]

#8726: Inaccurate length display / detection (m4a files)
-------------------------------------+-------------------------------------
             Reporter:  sandreas     |                     Type:  defect
               Status:  new          |                 Priority:  normal
            Component:               |                  Version:
  undetermined                       |  unspecified
             Keywords:  inaccurate   |               Blocked By:
  length, time display               |
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
 ffmpeg seems not to be able to show / dump the accurate length of a file
 in milliseconds. The example file has an accurate length of 15.832 seconds
 (15832ms) and now i would like to find out the exact length with ffmpeg,
 but it always cuts it down to 15.83 seconds (15830ms). I think it might
 have to do something with the time format always truncated to two decimal
 places for milliseconds.

 Is there a way to come across this?


 How to reproduce:
 {{{
 wget -c https://dl.espressif.com/dl/audio/gs-16b-2c-44100hz.m4a

 ffmpeg -hide_banner -i gs-16b-2c-44100hz.m4a -f null -

 #...
 #  Duration: 00:00:15.83, start: 0.000000, bitrate: 690 kb/s
 #...
 #size=N/A time=00:00:15.83 bitrate=N/A speed= 346x


 ffmpeg -hide_banner -i gs-16b-2c-44100hz.m4a -f ffmetadata -

 #...
 #  Duration: 00:00:15.83, start: 0.000000, bitrate: 690 kb/s
 #...
 #size=       0kB time=-577014:32:22.77 bitrate=N/A speed=N/A


 mp4info gs-16b-2c-44100hz.m4a

 #mp4info version 2.0.0
 #gs-16b-2c-44100hz.m4a:
 #1      audio   alac, 15.832 secs, 690 kbps, 44100 Hz
 }}}

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Ticket URL: <https://trac.ffmpeg.org/ticket/8726>
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