libavdevice/alsa-audio-common.c File Reference

ALSA input and output: common code. More...

#include <alsa/asoundlib.h>
#include "avdevice.h"
#include "alsa-audio.h"

Go to the source code of this file.

Defines
#define	REORDER_OUT_50(NAME, TYPE)
#define	REORDER_OUT_51(NAME, TYPE)
#define	REORDER_OUT_71(NAME, TYPE)
#define	REORDER_DUMMY   ((void *)1)
Functions
static av_cold snd_pcm_format_t	codec_id_to_pcm_format (int codec_id)
static av_cold ff_reorder_func	find_reorder_func (int codec_id, int64_t layout, int out)
av_cold int	ff_alsa_open (AVFormatContext *ctx, snd_pcm_stream_t mode, unsigned int *sample_rate, int channels, enum CodecID *codec_id)
	Open an ALSA PCM.
av_cold int	ff_alsa_close (AVFormatContext *s1)
	Close the ALSA PCM.
int	ff_alsa_xrun_recover (AVFormatContext *s1, int err)
	Try to recover from ALSA buffer underrun.
int	ff_alsa_extend_reorder_buf (AlsaData *s, int min_size)

---

Detailed Description

ALSA input and output: common code.

Author:

Luca Abeni ( lucabe72 email it )

Benoit Fouet ( benoit fouet free fr )

Nicolas George ( nicolas george normalesup org )

Definition in file alsa-audio-common.c.

---

Define Documentation

#define REORDER_DUMMY   ((void *)1)

Definition at line 128 of file alsa-audio-common.c.

Referenced by ff_alsa_open(), and find_reorder_func().

#define REORDER_OUT_50	(	NAME,
		TYPE		)

Value:

static void alsa_reorder_ ## NAME ## _out_50(const void *in_v, void *out_v, int n) \
{ \
    const TYPE *in = in_v; \
    TYPE * out = out_v; \
\
    while (n-- > 0) { \
        out[0] = in[0]; \
        out[1] = in[1]; \
        out[2] = in[3]; \
        out[3] = in[4]; \
        out[4] = in[2]; \
        in  += 5; \
        out += 5; \
    } \
}

Definition at line 63 of file alsa-audio-common.c.

#define REORDER_OUT_51	(	NAME,
		TYPE		)

Value:

static void alsa_reorder_ ## NAME ## _out_51(const void *in_v, void *out_v, int n) \
{ \
    const TYPE *in = in_v; \
    TYPE * out = out_v; \
\
    while (n-- > 0) { \
        out[0] = in[0]; \
        out[1] = in[1]; \
        out[2] = in[4]; \
        out[3] = in[5]; \
        out[4] = in[2]; \
        out[5] = in[3]; \
        in  += 6; \
        out += 6; \
    } \
}

Definition at line 80 of file alsa-audio-common.c.

#define REORDER_OUT_71	(	NAME,
		TYPE		)

Value:

static void alsa_reorder_ ## NAME ## _out_71(const void *in_v, void *out_v, int n) \
{ \
    const TYPE *in = in_v; \
    TYPE * out = out_v; \
\
    while (n-- > 0) { \
        out[0] = in[0]; \
        out[1] = in[1]; \
        out[2] = in[4]; \
        out[3] = in[5]; \
        out[4] = in[2]; \
        out[5] = in[3]; \
        out[6] = in[6]; \
        out[7] = in[7]; \
        in  += 8; \
        out += 8; \
    } \
}

Definition at line 98 of file alsa-audio-common.c.

---

Function Documentation

static av_cold snd_pcm_format_t codec_id_to_pcm_format

(

int

codec_id

)

[static]

Definition at line 36 of file alsa-audio-common.c.

Referenced by ff_alsa_open().

av_cold int ff_alsa_close

(

AVFormatContext *

s1

)

Close the ALSA PCM.

Parameters:

s1

media file handle

Returns:

0

Definition at line 307 of file alsa-audio-common.c.

int ff_alsa_extend_reorder_buf	(	AlsaData *	s,
		int	min_size
	)

Definition at line 337 of file alsa-audio-common.c.

Referenced by audio_write_packet().

av_cold int ff_alsa_open	(	AVFormatContext *	s,
		snd_pcm_stream_t	mode,
		unsigned int *	sample_rate,
		int	channels,
		enum CodecID *	codec_id
	)

Open an ALSA PCM.

Parameters:

	s	media file handle
	mode	either SND_PCM_STREAM_CAPTURE or SND_PCM_STREAM_PLAYBACK
	sample_rate	in: requested sample rate; out: actually selected sample rate
	channels	number of channels
	codec_id	in: requested CodecID or CODEC_ID_NONE; out: actually selected CodecID, changed only if CODEC_ID_NONE was requested

Returns:

0 if OK, AVERROR_xxx on error

Definition at line 170 of file alsa-audio-common.c.

Referenced by audio_read_header(), and audio_write_header().

int ff_alsa_xrun_recover	(	AVFormatContext *	s1,
		int	err
	)

Try to recover from ALSA buffer underrun.

Parameters:

	s1	media file handle
	err	error code reported by the previous ALSA call

Returns:

0 if OK, AVERROR_xxx on error

Definition at line 316 of file alsa-audio-common.c.

Referenced by audio_read_packet(), and audio_write_packet().

static av_cold ff_reorder_func find_reorder_func	(	int	codec_id,
		int64_t	layout,
		int	out
	)			[static]

Definition at line 130 of file alsa-audio-common.c.

Referenced by ff_alsa_open().