PCM HW Plugin Interface.
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| enum | { CHMAP_CTL_QUERY
, CHMAP_CTL_GET
, CHMAP_CTL_SET
} |
| |
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| snd_pcm_chmap_query_t ** | snd_pcm_query_chmaps_from_hw (int card, int dev, int subdev, snd_pcm_stream_t stream) |
| |
| int | snd_pcm_hw_open_fd (snd_pcm_t **pcmp, const char *name, int fd, int sync_ptr_ioctl) |
| | Creates a new hw PCM.
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| |
| int | snd_pcm_hw_open (snd_pcm_t **pcmp, const char *name, int card, int device, int subdevice, snd_pcm_stream_t stream, int mode, int mmap_emulation, int sync_ptr_ioctl) |
| | Creates a new hw PCM.
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| |
| int | _snd_pcm_hw_open (snd_pcm_t **pcmp, const char *name, snd_config_t *root, snd_config_t *conf, snd_pcm_stream_t stream, int mode) |
| | Creates a new hw PCM.
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| |
◆ hw_param_mask
| #define hw_param_mask |
( |
| params, |
|
|
| var ) |
Value: &((params)->masks[(var) - SND_PCM_HW_PARAM_FIRST_MASK])
◆ _snd_pcm_hw_open()
| int _snd_pcm_hw_open |
( |
snd_pcm_t ** | pcmp, |
|
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const char * | name, |
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snd_config_t * | root, |
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snd_config_t * | conf, |
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snd_pcm_stream_t | stream, |
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int | mode ) |
Creates a new hw PCM.
- Parameters
-
| pcmp | Returns created PCM handle |
| name | Name of PCM |
| root | Root configuration node |
| conf | Configuration node with hw PCM description |
| stream | PCM Stream |
| mode | PCM Mode |
- Warning
- Using of this function might be dangerous in the sense of compatibility reasons. The prototype might be freely changed in future.
◆ snd_pcm_hw_open()
| int snd_pcm_hw_open |
( |
snd_pcm_t ** | pcmp, |
|
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const char * | name, |
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int | card, |
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int | device, |
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int | subdevice, |
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snd_pcm_stream_t | stream, |
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int | mode, |
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int | mmap_emulation, |
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int | sync_ptr_ioctl ) |
Creates a new hw PCM.
- Parameters
-
| pcmp | Returns created PCM handle |
| name | Name of PCM |
| card | Number of card |
| device | Number of device |
| subdevice | Number of subdevice |
| stream | PCM Stream |
| mode | PCM Mode |
| mmap_emulation | Obsoleted parameter |
| sync_ptr_ioctl | Use SYNC_PTR ioctl rather than mmap for control structures |
- Return values
-
| zero | on success otherwise a negative error code |
- Warning
- Using of this function might be dangerous in the sense of compatibility reasons. The prototype might be freely changed in future.
◆ snd_pcm_hw_open_fd()
| int snd_pcm_hw_open_fd |
( |
snd_pcm_t ** | pcmp, |
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const char * | name, |
|
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int | fd, |
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int | sync_ptr_ioctl ) |
Creates a new hw PCM.
- Parameters
-
| pcmp | Returns created PCM handle |
| name | Name of PCM |
| fd | File descriptor |
| sync_ptr_ioctl | Boolean flag for sync_ptr ioctl |
- Return values
-
| zero | on success otherwise a negative error code |
- Warning
- Using of this function might be dangerous in the sense of compatibility reasons. The prototype might be freely changed in future.
◆ snd_pcm_query_chmaps_from_hw()
| snd_pcm_chmap_query_t ** snd_pcm_query_chmaps_from_hw |
( |
int | card, |
|
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int | dev, |
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int | subdev, |
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snd_pcm_stream_t | stream ) |
!brief Query the available channel maps
- Parameters
-
| card | the card number |
| dev | the PCM device number |
| subdev | the PCM substream index |
| stream | the direction of PCM stream |
- Returns
- the NULL-terminated array of integer pointers, or NULL at error.
This function works like snd_pcm_query_chmaps() but it takes the card, device, substream and stream numbers instead of the already opened snd_pcm_t instance, so that you can query available channel maps of a PCM before actually opening it.
As the parameters stand, the query is performed only to the hw PCM devices, not the abstracted PCM object in alsa-lib.