alsa-audio-common.c File Reference

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

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

Go to the source code of this file.

Macros
#define	REORDER_OUT_50(NAME, TYPE)
#define	REORDER_OUT_51(NAME, TYPE)
#define	REORDER_OUT_71(NAME, TYPE)
#define	FORMAT_I8   0
#define	FORMAT_I16   1
#define	FORMAT_I32   2
#define	FORMAT_F32   3
#define	PICK_REORDER(layout)

Functions
static av_cold snd_pcm_format_t	codec_id_to_pcm_format (int codec_id)
static av_cold int	find_reorder_func (AlsaData *s, int codec_id, uint64_t layout, int out)
av_cold int	ff_alsa_open (AVFormatContext *ctx, snd_pcm_stream_t mode, unsigned int *sample_rate, int channels, enum AVCodecID *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.

Macro Definition Documentation

#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 65 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 82 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 100 of file alsa-audio-common.c.

#define FORMAT_I8   0

Definition at line 133 of file alsa-audio-common.c.

Referenced by find_reorder_func().

#define FORMAT_I16   1

Definition at line 134 of file alsa-audio-common.c.

Referenced by find_reorder_func().

#define FORMAT_I32   2

Definition at line 135 of file alsa-audio-common.c.

Referenced by find_reorder_func().

#define FORMAT_F32   3

Definition at line 136 of file alsa-audio-common.c.

Referenced by find_reorder_func().

#define PICK_REORDER

(

layout

)

Value:

switch(format) {\
    case FORMAT_I8:  s->reorder_func = alsa_reorder_int8_out_ ##layout;  break;\
    case FORMAT_I16: s->reorder_func = alsa_reorder_int16_out_ ##layout; break;\
    case FORMAT_I32: s->reorder_func = alsa_reorder_int32_out_ ##layout; break;\
    case FORMAT_F32: s->reorder_func = alsa_reorder_f32_out_ ##layout;   break;\
}

Definition at line 138 of file alsa-audio-common.c.

Referenced by find_reorder_func().

Function Documentation

static av_cold snd_pcm_format_t codec_id_to_pcm_format ( int  codec_id )

static

Definition at line 38 of file alsa-audio-common.c.

Referenced by ff_alsa_open().

static av_cold int find_reorder_func ( AlsaData *  s, int  codec_id, uint64_t  layout, int  out  )

static

Definition at line 146 of file alsa-audio-common.c.

Referenced by ff_alsa_open().

av_cold int ff_alsa_open	(	AVFormatContext *	s,
		snd_pcm_stream_t	mode,
		unsigned int *	sample_rate,
		int	channels,
		enum AVCodecID *	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 AVCodecID or AV_CODEC_ID_NONE; out: actually selected AVCodecID, changed only if AV_CODEC_ID_NONE was requested

Returns

0 if OK, AVERROR_xxx on error

Definition at line 186 of file alsa-audio-common.c.

Referenced by audio_read_header(), and audio_write_header().

av_cold int ff_alsa_close

(

AVFormatContext *

s1

)

Close the ALSA PCM.

Parameters

s1	media file handle

Returns

0

Definition at line 318 of file alsa-audio-common.c.

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 329 of file alsa-audio-common.c.

Referenced by audio_read_packet(), and audio_write_packet().

int ff_alsa_extend_reorder_buf	(	AlsaData *	s,
		int	min_size
	)

Definition at line 350 of file alsa-audio-common.c.

Referenced by audio_write_packet().