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Diffstat (limited to 'libaudio/alsa_audio.h')
-rw-r--r-- | libaudio/alsa_audio.h | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/libaudio/alsa_audio.h b/libaudio/alsa_audio.h new file mode 100644 index 0000000..3cb86d9 --- /dev/null +++ b/libaudio/alsa_audio.h @@ -0,0 +1,77 @@ +/* +** Copyright 2010, The Android Open-Source Project +** +** Licensed under the Apache License, Version 2.0 (the "License"); +** you may not use this file except in compliance with the License. +** You may obtain a copy of the License at +** +** http://www.apache.org/licenses/LICENSE-2.0 +** +** Unless required by applicable law or agreed to in writing, software +** distributed under the License is distributed on an "AS IS" BASIS, +** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +** See the License for the specific language governing permissions and +** limitations under the License. +*/ + +#ifndef _AUDIO_H_ +#define _AUDIO_H_ + +struct pcm; + +#define PCM_OUT 0x00000000 +#define PCM_IN 0x10000000 + +#define PCM_STEREO 0x00000000 +#define PCM_MONO 0x01000000 + +#define PCM_44100HZ 0x00000000 +#define PCM_48000HZ 0x00100000 +#define PCM_8000HZ 0x00200000 +#define PCM_RATE_MASK 0x00F00000 + +#define PCM_PERIOD_CNT_MIN 2 +#define PCM_PERIOD_CNT_SHIFT 16 +#define PCM_PERIOD_CNT_MASK (0xF << PCM_PERIOD_CNT_SHIFT) +#define PCM_PERIOD_SZ_MIN 128 +#define PCM_PERIOD_SZ_SHIFT 12 +#define PCM_PERIOD_SZ_MASK (0xF << PCM_PERIOD_SZ_SHIFT) + +/* Acquire/release a pcm channel. + * Returns non-zero on error + */ +struct pcm *pcm_open(unsigned flags); +int pcm_close(struct pcm *pcm); +int pcm_ready(struct pcm *pcm); + +/* Returns a human readable reason for the last error. */ +const char *pcm_error(struct pcm *pcm); + +/* Returns the buffer size (int bytes) that should be used for pcm_write. + * This will be 1/2 of the actual fifo size. + */ +unsigned pcm_buffer_size(struct pcm *pcm); + +/* Write data to the fifo. + * Will start playback on the first write or on a write that + * occurs after a fifo underrun. + */ +int pcm_write(struct pcm *pcm, void *data, unsigned count); +int pcm_read(struct pcm *pcm, void *data, unsigned count); + +struct mixer; +struct mixer_ctl; + +struct mixer *mixer_open(void); +void mixer_close(struct mixer *mixer); +void mixer_dump(struct mixer *mixer); + +struct mixer_ctl *mixer_get_control(struct mixer *mixer, + const char *name, unsigned index); +struct mixer_ctl *mixer_get_nth_control(struct mixer *mixer, unsigned n); + +int mixer_ctl_set(struct mixer_ctl *ctl, unsigned percent); +int mixer_ctl_select(struct mixer_ctl *ctl, const char *value); +void mixer_ctl_print(struct mixer_ctl *ctl); + +#endif |