Am 20.12.2015 um 14:53 schrieb Nicolas George: > Le decadi 30 frimaire, an CCXXIV, Matthias Hunstock a écrit : >> SDI just transports 16 mono channels of audio, without any implied >> semantic of what is in there. So the closest matching layouts are 2.0, >> 8.0 and 16.0, if they existed. > > That does not mean anything. The channel layout called 5.1 "exists" because > the convention has made it the short name for "front left + front right + > front center + rear left + rear right + subwoofer". It is just a convenient > name. > > "16.0" does not "exist" because there is not, at this time, an audio > configuration with 16 channels that is widely used.
Correct, it is unusual to have 16 channels in a track. And in SDI there is no concept of a track, just channels. > I have absolutely no idea what decklinks cards actually do, and in > particular where they take their audio. Decklink cards actually do just some bitbanging: take digital input in "raw" format (AFAIK UYVY422 10 bit, PCM 16bit) and copy that into your RAM. > If there is a layout that is way > more common than anything else, then it makes sense to have it the > default. Otherwise, it is better to leave the layout unspecified to > avoid leaking false information in output files. IMO the only common layout is 2ch stereo for the 2 channel case, though even that is a guess. In the case of 8 oder 16 channels, the layout should remain unspecified, if there is no problem inside FFmpeg with that. Another possibility is to demux each channel as a mono track. Would this make more sense? Regards _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
