[Libav-user] Is a delayed transcoding start for mp2 unavoidable due to format or tuneable?

Sebastian Guttenberg sgutten at ms2-gmbh.de
Mon Mar 5 15:39:44 EET 2018

I found a workaround now, involving the linux-command 'dd‘ .
Instead of using the original command which has 4 seconds of delay:

ffmpeg  -ss 4:0:0 -i M0495978.MP2 testLocal.mp3
I’m now using the following combination of dd (on Linux, in order to cut a portion of a file) and ffmpeg without noticable delay:

dd ibs=1152 skip=600000 count=200 if=
 | ffmpeg -i pipe:0 test.mp3

In my example file, my frames have a constant frame size of 1152 bytes with a duration of 24ms. So I skip 600000 blocks of 24ms which correspond to 4 hours.
This command starts transcoding without any noticable delay!
(See also the discussion around my related question http://ffmpeg.org/pipermail/libav-user/2018-March/010973.html)

More information about the Libav-user mailing list