[RFC PATCH 1/6] ALSA: compress: add Sample Rate Converter codec support

Shengjiu Wang shengjiu.wang at nxp.com
Tue Aug 6 20:26:38 AEST 2024


Add Sample Rate Converter(SRC) codec support, define the output
format and rate for SRC.

Signed-off-by: Shengjiu Wang <shengjiu.wang at nxp.com>
---
 include/uapi/sound/compress_offload.h | 2 ++
 include/uapi/sound/compress_params.h  | 9 ++++++++-
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/include/uapi/sound/compress_offload.h b/include/uapi/sound/compress_offload.h
index 98772b0cbcb7..8b2b72f94e26 100644
--- a/include/uapi/sound/compress_offload.h
+++ b/include/uapi/sound/compress_offload.h
@@ -112,10 +112,12 @@ struct snd_compr_codec_caps {
  * end of the track
  * @SNDRV_COMPRESS_ENCODER_DELAY: no of samples inserted by the encoder at the
  * beginning of the track
+ * @SNDRV_COMPRESS_SRC_RATIO_MOD: Resampling Ratio Modifier for sample rate converter
  */
 enum sndrv_compress_encoder {
 	SNDRV_COMPRESS_ENCODER_PADDING = 1,
 	SNDRV_COMPRESS_ENCODER_DELAY = 2,
+	SNDRV_COMPRESS_SRC_RATIO_MOD = 3,
 };
 
 /**
diff --git a/include/uapi/sound/compress_params.h b/include/uapi/sound/compress_params.h
index ddc77322d571..0843773ea6b4 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_SRC                   ((__u32) 0x00000011)
+#define SND_AUDIOCODEC_MAX                   SND_AUDIOCODEC_SRC
 
 /*
  * Profile and modes are listed with bit masks. This allows for a
@@ -324,6 +325,11 @@ struct snd_dec_ape {
 	__u32 seek_table_present;
 } __attribute__((packed, aligned(4)));
 
+struct snd_dec_src {
+	__u32 format_out;
+	__u32 rate_out;
+} __attribute__((packed, aligned(4)));
+
 union snd_codec_options {
 	struct snd_enc_wma wma;
 	struct snd_enc_vorbis vorbis;
@@ -334,6 +340,7 @@ 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_src src;
 } __attribute__((packed, aligned(4)));
 
 /** struct snd_codec_desc - description of codec capabilities
-- 
2.34.1



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