On Sat, Jan 1, 2022 at 5:11 PM Marton Balint <c...@passwd.hu> wrote: > > > > On Sat, 1 Jan 2022, Pierre-Anthony Lemieux wrote: > > > Minor suggestion below. > > > > In addition, will sample file(s) be added to FATE? Below are two examples: > > > > http://ffmpeg-imf-samples-public.s3.us-west-1.amazonaws.com/callout_51_l_r_c_lfe_ls_rs.mxf > > http://ffmpeg-imf-samples-public.s3.us-west-1.amazonaws.com/callout_51_l_c_r_ls_rs_lfe.mxf > > Good idea, can someone with access please upload these to the fate mxf > folder? > > [...] > > > I suggest adding the following audio channels, which are specified in > > SMPTE ST 2067-8 [1] and have a direct mapping to ffmpeg audio > > channels:AV_CH_STEREO_LEFT > > > > urn:smpte:ul:060e2b34.0401010d.03020120.03000000 (Left Total) -> > > AV_CH_STEREO_LEFT > > urn:smpte:ul:060e2b34.0401010d.03020120.04000000 (RightTotal) -> > > AV_CH_STEREO_RIGHT > > > > [1] https://registry.smpte-ra.org/view/published/labels_view.html > > Unfortunately this is a Dolby encoded stereo mix, not an ordinary LeftOnly > / RightOnly mix. So I am not how this should be signalled.
My interpretation below. In "mov_chan.c", AV_CH_LAYOUT_STEREO_DOWNMIX means MOV_CH_LAYOUT_MATRIXSTEREO [1], which is defined in Core Audio [2]. LtRt, i.e. matrix-encoded audio, is not generally Dolby-specific [3]. [1] https://github.com/FFmpeg/FFmpeg/blob/d6b2357eddca392ee137cb2a92ff178a0a7d0cce/libavformat/mov_chan.c#L168 [2] https://developer.apple.com/documentation/coreaudiotypes/1572101-audio_channel_layout_tags/kaudiochannellayouttag_matrixstereo?changes=_8_7&language=objc [3] https://en.wikipedia.org/wiki/Matrix_decoder > > Regards, > Marton > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel > > To unsubscribe, visit link above, or email > ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe". _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
