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[PATCH RFC 1/2] ALSA: compress: add raw opus codec define and struct snd_dec_opus

Alexey Klimov posted 2 patches 3 months, 3 weeks ago
There is a newer version of this series
[PATCH RFC 1/2] ALSA: compress: add raw opus codec define and struct snd_dec_opus
Posted by Alexey Klimov 3 months, 3 weeks ago 
Adds a raw opus codec define and raw opus decoder struct.
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.

This is based on earlier work done by
Annemarie Porter <annemari@quicinc.com>

Cc: Annemarie Porter <annemari@quicinc.com>
Cc: Srinivas Kandagatla <srini@kernel.org>
Cc: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Alexey Klimov <alexey.klimov@linaro.org>
---
 include/uapi/sound/compress_params.h | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/include/uapi/sound/compress_params.h b/include/uapi/sound/compress_params.h
index bc7648a30746f4632ecf6695868e79550a431dfa..f80989f7bdd2f1bfad843b1dc30fa263e083d17a 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
 
 /*
  * Profile and modes are listed with bit masks. This allows for a
@@ -324,6 +325,23 @@ struct snd_dec_ape {
 	__u32 seek_table_present;
 } __attribute__((packed, aligned(4)));
 
+/*
+ * RFC with info on below OPUS decoder fields:
+ * https://www.rfc-editor.org/rfc/rfc7845#section-5
+ */
+struct snd_dec_opus {
+	__u8 version;		/* must be 1 */
+	__u8 num_channels;
+	__u16 pre_skip;
+	__u32 sample_rate;
+	__u16 output_gain;	/* in Q7.8 format */
+	__u8 mapping_family;
+	__u8 stream_count;	/* part of channel mapping */
+	__u8 coupled_count;	/* part of channel mapping */
+	__u8 channel_map;
+	__u8 reserved[7];	/* space for channel mapping */
+} __attribute__((packed, aligned(4)));
+
 union snd_codec_options {
 	struct snd_enc_wma wma;
 	struct snd_enc_vorbis vorbis;
@@ -334,6 +352,7 @@ 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
Re: [PATCH RFC 1/2] ALSA: compress: add raw opus codec define and struct snd_dec_opus
Posted by Srinivas Kandagatla 3 months, 3 weeks ago 

On 6/16/25 4:26 PM, Alexey Klimov wrote:
> Adds a raw opus codec define and raw opus decoder struct.
> 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.
> 
> This is based on earlier work done by
> Annemarie Porter <annemari@quicinc.com>
> 
May be co-dev by would be good option.

> Cc: Annemarie Porter <annemari@quicinc.com>
> Cc: Srinivas Kandagatla <srini@kernel.org>
> Cc: Vinod Koul <vkoul@kernel.org>
> Signed-off-by: Alexey Klimov <alexey.klimov@linaro.org>
> ---
>  include/uapi/sound/compress_params.h | 21 ++++++++++++++++++++-
>  1 file changed, 20 insertions(+), 1 deletion(-)
> 
> diff --git a/include/uapi/sound/compress_params.h b/include/uapi/sound/compress_params.h
> index bc7648a30746f4632ecf6695868e79550a431dfa..f80989f7bdd2f1bfad843b1dc30fa263e083d17a 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
>  
>  /*
>   * Profile and modes are listed with bit masks. This allows for a
> @@ -324,6 +325,23 @@ struct snd_dec_ape {
>  	__u32 seek_table_present;
>  } __attribute__((packed, aligned(4)));
>  
> +/*
> + * RFC with info on below OPUS decoder fields:
> + * https://www.rfc-editor.org/rfc/rfc7845#section-5
> + */
> +struct snd_dec_opus {
> +	__u8 version;		/* must be 1 */
> +	__u8 num_channels;
> +	__u16 pre_skip;
> +	__u32 sample_rate;
> +	__u16 output_gain;	/* in Q7.8 format */
> +	__u8 mapping_family;

This is where optional Channel Mapping Table starts in the structure.

Should this all these channel mapping memnbers go into a dedicated
struct snd_dec_opus_ch_map?

> +	__u8 stream_count;	/* part of channel mapping */
> +	__u8 coupled_count;	/* part of channel mapping */
Comments are bit misleading. Either we document them in detail or point to
the rfc which has this documented in more detail.

> +	__u8 channel_map;

Channel Mapping is (8*C bits), one octet per output channel.

The way this is represented/split in this struct is confusing should it
be just channel_map[8]


> +	__u8 reserved[7];	/* space for channel mapping */
Any reason only 7?

> +} __attribute__((packed, aligned(4)));
> +
>  union snd_codec_options {
>  	struct snd_enc_wma wma;
>  	struct snd_enc_vorbis vorbis;
> @@ -334,6 +352,7 @@ 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;
>
Re: [PATCH RFC 1/2] ALSA: compress: add raw opus codec define and struct snd_dec_opus
Posted by Alexey Klimov 1 month, 2 weeks ago 
On Wed Jun 18, 2025 at 1:33 PM BST, Srinivas Kandagatla wrote:
>
>
> On 6/16/25 4:26 PM, Alexey Klimov wrote:
>> Adds a raw opus codec define and raw opus decoder struct.
>> 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.
>> 
>> This is based on earlier work done by
>> Annemarie Porter <annemari@quicinc.com>
>> 
> May be co-dev by would be good option.

Ack.

>> Cc: Annemarie Porter <annemari@quicinc.com>
>> Cc: Srinivas Kandagatla <srini@kernel.org>
>> Cc: Vinod Koul <vkoul@kernel.org>
>> Signed-off-by: Alexey Klimov <alexey.klimov@linaro.org>
>> ---
>>  include/uapi/sound/compress_params.h | 21 ++++++++++++++++++++-
>>  1 file changed, 20 insertions(+), 1 deletion(-)
>> 
>> diff --git a/include/uapi/sound/compress_params.h b/include/uapi/sound/compress_params.h
>> index bc7648a30746f4632ecf6695868e79550a431dfa..f80989f7bdd2f1bfad843b1dc30fa263e083d17a 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
>>  
>>  /*
>>   * Profile and modes are listed with bit masks. This allows for a
>> @@ -324,6 +325,23 @@ struct snd_dec_ape {
>>  	__u32 seek_table_present;
>>  } __attribute__((packed, aligned(4)));
>>  
>> +/*
>> + * RFC with info on below OPUS decoder fields:
>> + * https://www.rfc-editor.org/rfc/rfc7845#section-5
>> + */
>> +struct snd_dec_opus {
>> +	__u8 version;		/* must be 1 */
>> +	__u8 num_channels;
>> +	__u16 pre_skip;
>> +	__u32 sample_rate;
>> +	__u16 output_gain;	/* in Q7.8 format */
>> +	__u8 mapping_family;
>
> This is where optional Channel Mapping Table starts in the structure.
>
> Should this all these channel mapping memnbers go into a dedicated
> struct snd_dec_opus_ch_map?

Ok.

>> +	__u8 stream_count;	/* part of channel mapping */
>> +	__u8 coupled_count;	/* part of channel mapping */
> Comments are bit misleading. Either we document them in detail or point to
> the rfc which has this documented in more detail.

Ok.

>> +	__u8 channel_map;
>
> Channel Mapping is (8*C bits), one octet per output channel.
>
> The way this is represented/split in this struct is confusing should it
> be just channel_map[8]
>
>
>> +	__u8 reserved[7];	/* space for channel mapping */
> Any reason only 7?

It was 7 because 1+7=8. For RFC 7845 the mappin family 0 and 1 only
actually make sense for playback hence max number of channels seems to
be 8.
I'll update it in the next version.

Thank you,
Alexey Klimov

Patchew 2.1-devel-b67e4c2

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