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author | Takashi Iwai <tiwai@suse.de> | 2012-07-27 16:27:00 (GMT) |
---|---|---|
committer | Takashi Iwai <tiwai@suse.de> | 2012-09-06 16:01:16 (GMT) |
commit | 2d3391ec0ecca37efb6bc995906292f47522b471 (patch) | |
tree | 129e8bce7b18bb9de48d6bc0e63806d22b40ad99 /include | |
parent | a8d372f171db9b90a64778fbcd9237c9bc256e06 (diff) | |
download | linux-2d3391ec0ecca37efb6bc995906292f47522b471.tar.xz |
ALSA: PCM: channel mapping API implementation
This patch implements the basic data types for the standard channel
mapping API handling.
- The definitions of the channel positions and the new TLV types are
added in sound/asound.h and sound/tlv.h, so that they can be
referred from user-space.
- Introduced a new helper function snd_pcm_add_chmap_ctls() to create
control elements representing the channel maps for each PCM
(sub)stream.
- Some standard pre-defined channel maps are provided for
convenience.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'include')
-rw-r--r-- | include/sound/asound.h | 30 | ||||
-rw-r--r-- | include/sound/pcm.h | 48 | ||||
-rw-r--r-- | include/sound/tlv.h | 8 |
3 files changed, 86 insertions, 0 deletions
diff --git a/include/sound/asound.h b/include/sound/asound.h index 0876a1e..376e756 100644 --- a/include/sound/asound.h +++ b/include/sound/asound.h @@ -472,6 +472,36 @@ enum { SNDRV_PCM_TSTAMP_TYPE_LAST = SNDRV_PCM_TSTAMP_TYPE_MONOTONIC, }; +/* channel positions */ +enum { + SNDRV_CHMAP_UNKNOWN = 0, + SNDRV_CHMAP_FL, /* front left */ + SNDRV_CHMAP_FC, /* front center */ + SNDRV_CHMAP_FR, /* front right */ + SNDRV_CHMAP_FLC, /* front left center */ + SNDRV_CHMAP_FRC, /* front right center */ + SNDRV_CHMAP_RL, /* rear left */ + SNDRV_CHMAP_RC, /* rear center */ + SNDRV_CHMAP_RR, /* rear right */ + SNDRV_CHMAP_RLC, /* rear left center */ + SNDRV_CHMAP_RRC, /* rear right center */ + SNDRV_CHMAP_SL, /* side left */ + SNDRV_CHMAP_SR, /* side right */ + SNDRV_CHMAP_LFE, /* LFE */ + SNDRV_CHMAP_FLW, /* front left wide */ + SNDRV_CHMAP_FRW, /* front right wide */ + SNDRV_CHMAP_FLH, /* front left high */ + SNDRV_CHMAP_FCH, /* front center high */ + SNDRV_CHMAP_FRH, /* front right high */ + SNDRV_CHMAP_TC, /* top center */ + SNDRV_CHMAP_NA, /* N/A, silent */ + SNDRV_CHMAP_LAST = SNDRV_CHMAP_NA, +}; + +#define SNDRV_CHMAP_POSITION_MASK 0xffff +#define SNDRV_CHMAP_PHASE_INVERSE (0x01 << 16) +#define SNDRV_CHMAP_DRIVER_SPEC (0x02 << 16) + #define SNDRV_PCM_IOCTL_PVERSION _IOR('A', 0x00, int) #define SNDRV_PCM_IOCTL_INFO _IOR('A', 0x01, struct snd_pcm_info) #define SNDRV_PCM_IOCTL_TSTAMP _IOW('A', 0x02, int) diff --git a/include/sound/pcm.h b/include/sound/pcm.h index cdca2ab..669c85a 100644 --- a/include/sound/pcm.h +++ b/include/sound/pcm.h @@ -437,6 +437,7 @@ struct snd_pcm_str { struct snd_info_entry *proc_xrun_debug_entry; #endif #endif + struct snd_kcontrol *chmap_kctl; /* channel-mapping controls */ }; struct snd_pcm { @@ -1086,4 +1087,51 @@ static inline const char *snd_pcm_stream_str(struct snd_pcm_substream *substream return "Capture"; } +/* + * PCM channel-mapping control API + */ +/* array element of channel maps */ +struct snd_pcm_chmap_elem { + unsigned char channels; + unsigned char map[15]; +}; + +/* channel map information; retrieved via snd_kcontrol_chip() */ +struct snd_pcm_chmap { + struct snd_pcm *pcm; /* assigned PCM instance */ + int stream; /* PLAYBACK or CAPTURE */ + struct snd_kcontrol *kctl; + const struct snd_pcm_chmap_elem *chmap; + unsigned int max_channels; + unsigned int channel_mask; /* optional: active channels bitmask */ + void *private_data; /* optional: private data pointer */ +}; + +/* get the PCM substream assigned to the given chmap info */ +static inline struct snd_pcm_substream * +snd_pcm_chmap_substream(struct snd_pcm_chmap *info, unsigned int idx) +{ + struct snd_pcm_substream *s; + for (s = info->pcm->streams[info->stream].substream; s; s = s->next) + if (s->number == idx) + return s; + return NULL; +} + +/* ALSA-standard channel maps (RL/RR prior to C/LFE) */ +extern const struct snd_pcm_chmap_elem snd_pcm_std_chmaps[]; +/* Other world's standard channel maps (C/LFE prior to RL/RR) */ +extern const struct snd_pcm_chmap_elem snd_pcm_alt_chmaps[]; + +/* bit masks to be passed to snd_pcm_chmap.channel_mask field */ +#define SND_PCM_CHMAP_MASK_24 ((1U << 2) | (1U << 4)) +#define SND_PCM_CHMAP_MASK_246 (SND_PCM_CHMAP_MASK_24 | (1U << 6)) +#define SND_PCM_CHMAP_MASK_2468 (SND_PCM_CHMAP_MASK_246 | (1U << 8)) + +int snd_pcm_add_chmap_ctls(struct snd_pcm *pcm, int stream, + const struct snd_pcm_chmap_elem *chmap, + int max_channels, + unsigned long private_value, + struct snd_pcm_chmap **info_ret); + #endif /* __SOUND_PCM_H */ diff --git a/include/sound/tlv.h b/include/sound/tlv.h index a64d8fe..28c65e1 100644 --- a/include/sound/tlv.h +++ b/include/sound/tlv.h @@ -86,4 +86,12 @@ #define TLV_DB_GAIN_MUTE -9999999 +/* + * channel-mapping TLV items + * TLV length must match with num_channels + */ +#define SNDRV_CTL_TLVT_CHMAP_FIXED 0x101 /* fixed channel position */ +#define SNDRV_CTL_TLVT_CHMAP_VAR 0x102 /* channels freely swappable */ +#define SNDRV_CTL_TLVT_CHMAP_PAIRED 0x103 /* pair-wise swappable */ + #endif /* __SOUND_TLV_H */ |