diff options
author | Takashi Iwai <tiwai@suse.de> | 2012-07-27 18:27:00 +0200 |
---|---|---|
committer | Takashi Iwai <tiwai@suse.de> | 2012-09-06 18:01:16 +0200 |
commit | 2d3391ec0ecca37efb6bc995906292f47522b471 (patch) | |
tree | 129e8bce7b18bb9de48d6bc0e63806d22b40ad99 /include/sound/pcm.h | |
parent | a8d372f171db9b90a64778fbcd9237c9bc256e06 (diff) |
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/sound/pcm.h')
-rw-r--r-- | include/sound/pcm.h | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/include/sound/pcm.h b/include/sound/pcm.h index cdca2ab1e71..669c85a7fb0 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 */ |