Hi Marc, You're right, I thought that this would be easy but I passed the last hour trying like you and also with flac.exe command line tool using the -ogg flag.
I used a 16 channel file and the error from the flac utility was that it wasn't a wavefile extensible and couldn't mark channels, so I opened my test file using Audition and defined the wavefile extensible as higher order ambisonics, after that the error I got from the flac encoder was unsupported number of channels. I don't really know how this can be done :-( If you have any news please let me know. Cheers! *Pan Athen* SoundFellas <https://soundfellas.com/>, *MediaFlake Ltd <http://mediaflake.com/>* Digital Media Services, Content, and Tools On Sun, Apr 30, 2023 at 10:00 PM Marc Lavallée <m...@hacklava.net> wrote: > Hi Panos, > > The Ogg FLAC documentation does not mention that more than 8 channels > can be encoded. > > I tried using ffmpeg; this is working for 8 channels: > > ffmpeg -f lavfi -i "anoisesrc=d=1:c=pink:a=0.5" -c:a flac -f ogg -ac 8 > -y noise-8c.ogg > > But this is not working for 16 channels: > > ffmpeg -f lavfi -i "anoisesrc=d=1:c=pink:a=0.5" -c:a flac -f ogg -ac 16 > -y noise-16c.ogg > > The returned error is: "[flac @ 0x562603bd8540] 16 channels not > supported (max 8)" > > And when specifying a channel number higher than 8 but lower than 16, > the result is a mono file. > > It could be that ffmpeg is not capable of encoding more than 8 channels > for FLAC streams. > > What tool (or method) would you suggest to encode more than 8 channels > in a Ogg container? > > Marc > > Le 2023-04-30 à 14 h 11, Panos Kouvelis a écrit : > > Native FLAC can support up to 8 channels; you are right. > > > > To support more channels using FLAC, you should use Ogg FLAC, an OGG > > container containing FLAC-encoded material. > > > > If that helps you, you can find more here: > > https://xiph.org/flac/faq.html#general__native_vs_ogg > > Here: https://xiph.org/flac/faq.html#general__native_or_ogg > > And here: https://xiph.org/flac/ogg_mapping.html > > > > I hope that helps in your case. > > > > Cheers! > > > > *Pan Athen* > > SoundFellas <https://soundfellas.com/>, *MediaFlake Ltd > > <http://mediaflake.com/>* > > Digital Media Services, Content, and Tools > > > > > > On Sun, Apr 30, 2023 at 9:02 PM Bo-Erik Sandholm <bosses...@gmail.com> > > wrote: > > > >> Can someone comment on the double message i think i find in the spec? > >> > >> There is a the specification of max number of channels in stream info > >> chapter 8.2 > >> > >> u(3) | (number of channels)-1. FLAC supports from 1 to | > >> | | 8 channels. > >> > >> > >> In chapter 8.6.2 > >> > >> A WAVEFORMATEXTENSIBLE_CHANNEL_MASK field of 0x0 can be used to > >> indicate that none of the audio channels of a file correlate with > >> speaker positions. This is the case when audio needs to be decoded > >> into speaker positions (e.g. Ambisonics B-format audio) or when a > >> multitrack recording is contained. > >> > >> > >> ..... > >> > >> What does this mean? > >> > >> Is it that ambisonics cannot be streamed in second or third order with > >> flac? > >> > >> > >> In todays widebandwith internet this feels a bit too restrictive, is > >> it a Dolby business thing? > >> > >> > >> https://datatracker.ietf.org/doc/draft-ietf-cellar-flac/ > >> > >> Any information or ideas about this? > >> > >> Bosse Sandholm > >> Ambisonics hobbyist. > -------------- next part -------------- An HTML attachment was scrubbed... URL: <https://mail.music.vt.edu/mailman/private/sursound/attachments/20230501/1c9589ca/attachment.htm> _______________________________________________ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe here, edit account or options, view archives and so on.
