Re: [PATCH 1/2] ALSA: compress: add raw opus codec define and opus decoder structs
From: Vinod Koul
Date: Thu Aug 21 2025 - 01:02:00 EST
On 20-08-25, 22:15, Alexey Klimov wrote:
> Adds a raw opus codec define and raw opus decoder structs.
> This is for raw OPUS packets not packed in any type of container
> (for instance OGG container). The decoder struct fields are
> taken from corresponding RFC document: RFC 7845 Section 5.
>
> Cc: Srinivas Kandagatla <srini@xxxxxxxxxx>
> Cc: Vinod Koul <vkoul@xxxxxxxxxx>
> Co-developed-by: Annemarie Porter <annemari@xxxxxxxxxxx>
> Signed-off-by: Annemarie Porter <annemari@xxxxxxxxxxx>
> Signed-off-by: Alexey Klimov <alexey.klimov@xxxxxxxxxx>
> ---
> include/uapi/sound/compress_params.h | 43 +++++++++++++++++++++++++++++++++++-
> 1 file changed, 42 insertions(+), 1 deletion(-)
>
> diff --git a/include/uapi/sound/compress_params.h b/include/uapi/sound/compress_params.h
> index bc7648a30746f4632ecf6695868e79550a431dfa..faf4fa911f7fc2830c3ae42b93650fe40d8a776b 100644
> --- a/include/uapi/sound/compress_params.h
> +++ b/include/uapi/sound/compress_params.h
> @@ -43,7 +43,8 @@
> #define SND_AUDIOCODEC_BESPOKE ((__u32) 0x0000000E)
> #define SND_AUDIOCODEC_ALAC ((__u32) 0x0000000F)
> #define SND_AUDIOCODEC_APE ((__u32) 0x00000010)
> -#define SND_AUDIOCODEC_MAX SND_AUDIOCODEC_APE
> +#define SND_AUDIOCODEC_OPUS_RAW ((__u32) 0x00000011)
> +#define SND_AUDIOCODEC_MAX SND_AUDIOCODEC_OPUS_RAW
we should bump API minor version with this
>
> /*
> * Profile and modes are listed with bit masks. This allows for a
> @@ -324,6 +325,45 @@ struct snd_dec_ape {
> __u32 seek_table_present;
> } __attribute__((packed, aligned(4)));
>
> +/**
> + * struct snd_dec_opus - Opus decoder parameters (raw opus packets)
> + * @version: Usually should be '1' but can be split into major (4 upper bits)
> + * and minor (4 lower bits) sub-fields.
Please define bits, this is an ABI so needs to be properly defined
> + * @num_channels: Number of output channels.
> + * @pre_skip: Number of samples to discard at 48 kHz.
> + * @sample_rate: Sample rate of original input.
> + * @output_gain: Gain to apply when decoding (in Q7.8 format).
> + * @mapping_family: Order and meaning of output channels. Only values 0 and 1
> + * are expected; values 2..255 are not recommended for playback.
> + *
> + * Optional channel mapping table. Describes mapping of opus streams to decoded
> + * channels.
> + * @struct snd_dec_opus_ch_map
> + * @stream_count: Number of streams encoded in each Ogg packet.
> + * @coupled_count: Number of streams whose decoders are used for two
> + * channels.
> + * @channel_map: describes which decoded channel to be used for each one.
> + * See RFC doc for details.
> + * This supports only mapping families 0 and 1, therefore max
> + * number of channels is 8.
> + *
> + * These options were extracted from RFC7845 Section 5.
> + */
> +
> +struct snd_dec_opus {
> + __u8 version;
> + __u8 num_channels;
> + __u16 pre_skip;
> + __u32 sample_rate;
> + __u16 output_gain;
> + __u8 mapping_family;
> + struct snd_dec_opus_ch_map {
> + __u8 stream_count;
> + __u8 coupled_count;
> + __u8 channel_map[8];
> + } chan_map;
> +} __attribute__((packed, aligned(4)));
> +
> union snd_codec_options {
> struct snd_enc_wma wma;
> struct snd_enc_vorbis vorbis;
> @@ -334,6 +374,7 @@ union snd_codec_options {
> struct snd_dec_wma wma_d;
> struct snd_dec_alac alac_d;
> struct snd_dec_ape ape_d;
> + struct snd_dec_opus opus_d;
> struct {
> __u32 out_sample_rate;
> } src_d;
>
> --
> 2.47.2
--
~Vinod