On Wednesday 20 June 2018 17:35:42 Jan Alexander Steffens wrote: > On Mon, Jun 18, 2018, 09:42 Pali Rohár <pali.rohar at gmail.com> wrote: > > > On Sunday 17 June 2018 23:48:42 Arun Raghavan wrote: > > > On Sun, 17 Jun 2018, at 4:01 AM, Pali Rohár wrote: > > > > Hi! As you may know lot of bluetooth headsets support not only SBC, but > > > > also aptX codec. And new version of ffmpeg (4.0) has native aptX and > > > > aptX HD encoder and decoder. AptX codec itself is proprietary, but > > > > ffmpeg has clean-room implementation based on expired patent. What > > about > > > > adding support for aptX via ffmpeg into pulseaudio? > > > > > > > > -- > > > > > > I'd actually like to delete the SBC code and replace it with a generic > > GStreamer bin. That would allow us to be codec agnostic, and support any of > > the codecs that are supported by GStreamer (which includes those that > > ffmpeg provides). > > > > This does not sound like a good idea. The only two relevant bluetooth > > codecs for most people are SBC and aptX. > > > > Don't forget AAC. I've seen this one a lot in devices meant for use with > iPhones, which apparently don't have aptX. GStreamer has a lot of encoders > for it so this shouldn't be a problem unless it's some strange AAC variant. > > There's also LDAC but I haven't seen it on a device yet. I did some investigation and basically this is the list of all known codecs used in A2DP: Mandatory: 0x00 - SBC Optional: 0x01 - MPEG-1,2 (aka MP3) 0x02 - MPEG-2,4 (aka AAC) 0x04 - ATRAC Vendor specific: 0xFF 0x004F 0x01 - aptX 0xFF 0x000A 0x01 - FastStream 0xFF 0x000A 0x02 - aptX Low Latency 0xFF 0x00D7 0x24 - aptX HD 0xFF 0x012D 0xAA - LDAC And also I found some references that some sort of raw 16bit PCM samples via codec id 0x05 are used... But I have never seen such product. -- Pali Rohár pali.rohar at gmail.com -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 195 bytes Desc: not available URL: <https://lists.freedesktop.org/archives/pulseaudio-discuss/attachments/20180706/dc9b3124/attachment.sig>
