ALSA: add DSD formats

This patch adds two formats for Direct Stream Digital (DSD), a pulse-density encoding format which is described here: https://en.wikipedia.org/wiki/Direct_Stream_Digital DSD operates on 2.8, 5.6 or 11.2MHz sample rates and as a 1-bit stream. The two new types added by this patch describe streams that are capable of handling DSD samples in DOP format as 8-bit or in 16-bit (or at a x8 or x16 data rate, respectively). DSD itself specifies samples in *bit*, while DOP and ALSA handle them as *bytes*. Hence, a factor of 8 or 16 has to be applied for the sample rare configuration, according to the following table: configured hardware 176.4KHz 352.8kHz 705.6KHz <---- sample rate 8-bit 2.8MHz 5.6MHz 16-bit 2.8Mhz 5.6MHz 11.2MHz `-----------------------------' actual DSD sample rates Signed-off-by: Daniel Mack <[email protected]> Signed-off-by: Takashi Iwai <[email protected]>
chewitt · Apr 18, 2013 · ef7a4f9 · ef7a4f9
1 parent d5657ec
commit ef7a4f9
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Showing 4 changed files with 15 additions and 1 deletion.
diff --git a/include/sound/pcm.h b/include/sound/pcm.h
@@ -181,6 +181,8 @@ struct snd_pcm_ops {
 #define SNDRV_PCM_FMTBIT_G723_24_1B	_SNDRV_PCM_FMTBIT(G723_24_1B)
 #define SNDRV_PCM_FMTBIT_G723_40	_SNDRV_PCM_FMTBIT(G723_40)
 #define SNDRV_PCM_FMTBIT_G723_40_1B	_SNDRV_PCM_FMTBIT(G723_40_1B)
+#define SNDRV_PCM_FMTBIT_DSD_U8		_SNDRV_PCM_FMTBIT(DSD_U8)
+#define SNDRV_PCM_FMTBIT_DSD_U16_LE	_SNDRV_PCM_FMTBIT(DSD_U16_LE)
 
 #ifdef SNDRV_LITTLE_ENDIAN
 #define SNDRV_PCM_FMTBIT_S16		SNDRV_PCM_FMTBIT_S16_LE

diff --git a/include/uapi/sound/asound.h b/include/uapi/sound/asound.h
@@ -214,7 +214,9 @@ typedef int __bitwise snd_pcm_format_t;
 #define	SNDRV_PCM_FORMAT_G723_24_1B	((__force snd_pcm_format_t) 45) /* 1 sample in 1 byte */
 #define	SNDRV_PCM_FORMAT_G723_40	((__force snd_pcm_format_t) 46) /* 8 Samples in 5 bytes */
 #define	SNDRV_PCM_FORMAT_G723_40_1B	((__force snd_pcm_format_t) 47) /* 1 sample in 1 byte */
-#define	SNDRV_PCM_FORMAT_LAST		SNDRV_PCM_FORMAT_G723_40_1B
+#define	SNDRV_PCM_FORMAT_DSD_U8		((__force snd_pcm_format_t) 48) /* DSD, 1-byte samples DSD (x8) */
+#define	SNDRV_PCM_FORMAT_DSD_U16_LE	((__force snd_pcm_format_t) 49) /* DSD, 2-byte samples DSD (x16), little endian */
+#define	SNDRV_PCM_FORMAT_LAST		SNDRV_PCM_FORMAT_DSD_U16_LE
 
 #ifdef SNDRV_LITTLE_ENDIAN
 #define	SNDRV_PCM_FORMAT_S16		SNDRV_PCM_FORMAT_S16_LE

diff --git a/sound/core/pcm.c b/sound/core/pcm.c
@@ -209,6 +209,8 @@ static char *snd_pcm_format_names[] = {
 	FORMAT(G723_24_1B),
 	FORMAT(G723_40),
 	FORMAT(G723_40_1B),
+	FORMAT(DSD_U8),
+	FORMAT(DSD_U16_LE),
 };
 
 const char *snd_pcm_format_name(snd_pcm_format_t format)

diff --git a/sound/core/pcm_misc.c b/sound/core/pcm_misc.c
@@ -140,6 +140,14 @@ static struct pcm_format_data pcm_formats[(INT)SNDRV_PCM_FORMAT_LAST+1] = {
 		.width = 5, .phys = 5, .le = -1, .signd = -1,
 		.silence = {},
 	},
+	[SNDRV_PCM_FORMAT_DSD_U8] = {
+		.width = 8, .phys = 8, .le = 1, .signd = 0,
+		.silence = {},
+	},
+	[SNDRV_PCM_FORMAT_DSD_U16_LE] = {
+		.width = 16, .phys = 16, .le = 1, .signd = 0,
+		.silence = {},
+	},
 	/* FIXME: the following three formats are not defined properly yet */
 	[SNDRV_PCM_FORMAT_MPEG] = {
 		.le = -1, .signd = -1,