[FFmpeg-user] How to extract core DTS / DCA stream from a DTS 96/24 stream without re-encoding

[Carl Eugen Hoyos]

2018-05-19 15:05 GMT+02:00, Moritz Barsnick <barsnick at gmx.net>:
> On Sat, May 19, 2018 at 13:59:03 +0100, Onetel wrote:
>> Thanks - I tried this but it seems to re-encode rather than copy, taking
>> much longer than “-acodec copy” (which is instantaneous). I tried:
>>
>> ffmpeg -i in.dts -bsf:a dca_core -strict -2 out.dts
>
> You need to use both "-c:a copy" *and* "-bsf:a dca_core".

The filter does not yet work for 96/24 while -core_only works fine,
you can (for example) test with the following lines (using the file
you found):
$ ffmpeg -i sample.dts -f crc -
$ ffmpeg -core_only 1 -i sample.dts -f crc -
$ ffmpeg -i sample.dts -acodec copy -bsf:a dca_core out.dts
$ md5sum out.dts sample.dts

Carl Eugen