diff options
| author | Simon Wilson <simonwilson@google.com> | 2011-06-21 14:58:11 -0700 |
|---|---|---|
| committer | Simon Wilson <simonwilson@google.com> | 2011-06-24 11:05:08 -0700 |
| commit | d6458e6f62ea7d09a82f78f509df58c452358ae8 (patch) | |
| tree | 54e4687d27bd1fd8446e250584c5b95b9da03452 | |
| parent | bc03b620835886fb4de50ef1499200a9ca80a999 (diff) | |
pcm: add pcm_start/stop() functions for streams
This is essential for streams such as loopback devices that
do not transfer data.
| -rw-r--r-- | include/tinyalsa/asoundlib.h | 4 | ||||
| -rw-r--r-- | pcm.c | 19 |
2 files changed, 23 insertions, 0 deletions
diff --git a/include/tinyalsa/asoundlib.h b/include/tinyalsa/asoundlib.h index bd0cdee..14511c9 100644 --- a/include/tinyalsa/asoundlib.h +++ b/include/tinyalsa/asoundlib.h @@ -97,6 +97,10 @@ unsigned int pcm_get_latency(struct pcm *pcm); int pcm_write(struct pcm *pcm, void *data, unsigned int count); int pcm_read(struct pcm *pcm, void *data, unsigned int count); +/* Start and stop a PCM channel that doesn't transfer data */ +int pcm_start(struct pcm *pcm); +int pcm_stop(struct pcm *pcm); + /* * MIXER API @@ -350,3 +350,22 @@ int pcm_is_ready(struct pcm *pcm) { return pcm->fd >= 0; } + +int pcm_start(struct pcm *pcm) +{ + if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_PREPARE) < 0) + return oops(pcm, errno, "cannot prepare channel"); + if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_START) < 0) + return oops(pcm, errno, "cannot start channel"); + + return 0; +} + +int pcm_stop(struct pcm *pcm) +{ + if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_DROP) < 0) + return oops(pcm, errno, "cannot stop channel"); + + return 0; +} + |