On Sun, Jan 31, 2016 at 7:57 PM, James Almer <jamr...@gmail.com> wrote: > On 1/31/2016 3:51 PM, Michael Niedermayer wrote: >> On Sun, Jan 31, 2016 at 05:14:14PM +0100, foo86 wrote: >>> ffmpeg | branch: master | foo86 <fooba...@gmail.com> | Sat Jan 16 11:54:38 >>> 2016 +0300| [ae5b2c52501d5009fe712334428138a9b758849b] | committer: Hendrik >>> Leppkes >>> >>> avcodec/dca: add new decoder based on libdcadec >>> >>>> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=ae5b2c52501d5009fe712334428138a9b758849b >>> --- >>> >> >> >> this breaks request_channel_layout >> >> example: >> ./ffmpeg -i dts/lotr_5.1_768.dts test.wav >> >> Input #0, dts, from '/home/michael/videos/dts/lotr_5.1_768.dts': >> Duration: 00:02:05.18, start: 0.000000, bitrate: 768 kb/s >> Stream #0:0: Audio: dts (DTS-ES), 48000 Hz, 6.1, fltp, 768 kb/s >> >> >> vs. >> ./ffmpeg -request_channel_layout 3 -i dts/lotr_5.1_768.dts test-req3.wav >> >> Input #0, dts, from '/home/michael/videos/dts/lotr_5.1_768.dts': >> Duration: 00:02:05.18, start: 0.000000, bitrate: 768 kb/s >> Stream #0:0: Audio: dts (DTS), 48000 Hz, 5.1(side), fltp, 768 kb/s >> >> vs. >> ./ffmpeg-ref -request_channel_layout 3 -i dts/lotr_5.1_768.dts >> test-ref-req3.wav >> >> Input #0, dts, from '/home/michael/videos/dts/lotr_5.1_768.dts': >> Duration: 00:02:05.18, start: 0.000000, bitrate: 768 kb/s >> Stream #0:0: Audio: dts (DTS-ES), 48000 Hz, stereo, fltp, 768 kb/s >> >> >> previously it resulted in 2 channels now it produces 5.1 when >> requesting stereo > > libdcadec (and thus this new decoder) doesn't force stereo when downmix > coefficients are not embedded in the stream, leaving the work to the > resampler instead. Try the libdcadec wrapper and it will do the same. > > It's an intended change in behavior compared to the old dca decoder, so > i guess it could documented.
Indeed, the decoder will only honor the request when the bitstream contains information to do so, instead of forcing a generic downmix like the old one. 5.1 is always possible for >5.1 streams, but stereo requires the bitstream to contain coefficients. - Hendrik _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
