[pulseaudio-discuss] [PATCH 3/4] Add A2DP aptX, aptX HD codecs support

Pali Rohár pali.rohar at gmail.com
Thu Dec 13 15:43:46 UTC 2018

On Thursday 13 December 2018 19:43:38 EHfive wrote:
> diff --git a/src/modules/bluetooth/a2dp/a2dp-codecs.h b/src/modules/bluetooth/a2dp/a2dp-codecs.h
> index aefafb635..a6f054aec 100644
> --- a/src/modules/bluetooth/a2dp/a2dp-codecs.h
> +++ b/src/modules/bluetooth/a2dp/a2dp-codecs.h
> @@ -141,6 +141,9 @@
>  #define APTX_SAMPLING_FREQ_44100	0x02
>  #define APTX_SAMPLING_FREQ_48000	0x01
> +#define APTX_HD_VENDOR_ID			0x000000D7

This ID is assigned to Qualcomm Technologies, Inc. Not for aptX HD
codec, or aptX HD vendor.

> +#define APTX_HD_CODEC_ID			0x0024
> +
>  #define LDAC_VENDOR_ID			0x0000012d
>  #define LDAC_CODEC_ID			0x00aa

I wrote alternative implementation of aptX codec support for pulseaudio.
It does not use big ffmpeg, but rather small libopenaptx library from
https://github.com/pali/libopenaptx Patches are already in mailing list...

Anyway, aptX decoder (both hd and non-hd variants) in ffmpeg has delay
of about 90 samples. I have already some idea how to fix... and will try
to implement it in libopenaptx. (Recompiling ffmpeg just for testing and
debugging one codec is big pain; small library is better for this).

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/20181213/ad3f7c5b/attachment.sig>

More information about the pulseaudio-discuss mailing list