Re: Flac multi channel
Olivier Tristan <[email protected]>
| Newsgroups | gmane.comp.audio.compression.flac.devel |
|---|---|
| Message-ID | <[email protected]> |
Thanks everybody for their answer. This is quite unfortunate for me, but hey, that's life. I will probably end up doing some multi mono bundle similar to what Protools did back in the days with its .L .R files ++ Le 26/01/2017 à 18:58, Martin Leese a écrit : > Federico Miyara wrote: > ... >> The file format allows some unused fields for future use, such as the >> padding block. It could include a flag to indicate a change in the >> format adding one more streaminfo byte which would allow up to 256 >> channels (actually, 256 + 8), or it could trigger a new byte when 11111111. >> >> There is also an invalid block identifier (127) which could be used with >> the same purpose. > The problem isn't *just* the 3-bit field used for > the number of channels. As Brian Willoughby > explained: > ... >>> As you cram more channels into a block, you get fewer samples per block for >>> each individual channel. There simply isn't any advantage to having lots of >>> channels in a single stream. >>> >>> I believe that Ogg allows you to create a file that interleaves multiple >>> FLAC files. > Perhaps comparing FLAC with the Ogg > container and Vorbis codec will aid > understanding. > > With Ogg, different streams can be either > chained (sequential) or grouped > (parallel/interleaved). Typically, metadata > streams would be chained (so they appear > before any audio data) and audio streams > would be grouped. > > Within a single FLAC stream the audio is > split into blocks which are grouped. But within > each block the eight channels are chained. > This makes sense with a maximum of only > eight channels. Within a Vorbis stream the > audio is split into frames which are grouped. > Because a Vorbis stream can contain up to > 256 channels, within each frame the channels > are also grouped. > > So the maximum of eight channels is really > embedded into the FLAC standard. To change > this would require a whole new standard (or > the use of multiple grouped FLAC streams in > an Ogg container). > > Regards, > Martin -- Olivier Tristan Research & Development www.uvi.net _______________________________________________ flac-dev mailing list [email protected] http://lists.xiph.org/mailman/listinfo/flac-dev