Commit ef7a4f97 authored by Daniel Mack's avatar Daniel Mack Committed by Takashi Iwai
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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: default avatarDaniel Mack <zonque@gmail.com>
Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent d5657ec9

include/sound/pcm.h

+2 −0
Original line number Diff line number Diff line
@@ -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

include/uapi/sound/asound.h

+3 −1
Original line number Diff line number Diff line
@@ -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

sound/core/pcm.c

+2 −0
Original line number Diff line number Diff line
@@ -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)

sound/core/pcm_misc.c

+8 −0
Original line number Diff line number Diff line
@@ -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,

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