ALSA: implement channel layout for playback.

Currently quad, 5.0, 5.1 and 7.1 are implemented.
Implementing support for other formats/layouts and capture should be
straightforward.

5.0 and 7.1 support by Carl Eugen Hoyos.

Signed-off-by: Anton Khirnov <anton@khirnov.net>
This commit is contained in:
Nicolas George 2011-03-10 12:10:34 +01:00 committed by Anton Khirnov
parent 2359aeb52d
commit 147bcf27c4
3 changed files with 169 additions and 1 deletions

View File

@ -30,6 +30,7 @@
#include <alsa/asoundlib.h>
#include "libavformat/avformat.h"
#include "libavutil/avassert.h"
#include "alsa-audio.h"
@ -60,6 +61,127 @@ static av_cold snd_pcm_format_t codec_id_to_pcm_format(int codec_id)
}
}
#define REORDER_OUT_50(NAME, TYPE) \
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; \
} \
}
#define REORDER_OUT_51(NAME, TYPE) \
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; \
} \
}
#define REORDER_OUT_71(NAME, TYPE) \
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; \
} \
}
REORDER_OUT_50(int8, int8_t)
REORDER_OUT_51(int8, int8_t)
REORDER_OUT_71(int8, int8_t)
REORDER_OUT_50(int16, int16_t)
REORDER_OUT_51(int16, int16_t)
REORDER_OUT_71(int16, int16_t)
REORDER_OUT_50(int32, int32_t)
REORDER_OUT_51(int32, int32_t)
REORDER_OUT_71(int32, int32_t)
REORDER_OUT_50(f32, float)
REORDER_OUT_51(f32, float)
REORDER_OUT_71(f32, float)
#define FORMAT_I8 0
#define FORMAT_I16 1
#define FORMAT_I32 2
#define FORMAT_F32 3
#define PICK_REORDER(layout)\
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;\
}
static av_cold int find_reorder_func(AlsaData *s, int codec_id, int64_t layout, int out)
{
int format;
/* reordering input is not currently supported */
if (!out)
return AVERROR(ENOSYS);
/* reordering is not needed for QUAD or 2_2 layout */
if (layout == AV_CH_LAYOUT_QUAD || layout == AV_CH_LAYOUT_2_2)
return 0;
switch (codec_id) {
case CODEC_ID_PCM_S8:
case CODEC_ID_PCM_U8:
case CODEC_ID_PCM_ALAW:
case CODEC_ID_PCM_MULAW: format = FORMAT_I8; break;
case CODEC_ID_PCM_S16LE:
case CODEC_ID_PCM_S16BE:
case CODEC_ID_PCM_U16LE:
case CODEC_ID_PCM_U16BE: format = FORMAT_I16; break;
case CODEC_ID_PCM_S32LE:
case CODEC_ID_PCM_S32BE:
case CODEC_ID_PCM_U32LE:
case CODEC_ID_PCM_U32BE: format = FORMAT_I32; break;
case CODEC_ID_PCM_F32LE:
case CODEC_ID_PCM_F32BE: format = FORMAT_F32; break;
default: return AVERROR(ENOSYS);
}
if (layout == AV_CH_LAYOUT_5POINT0_BACK || layout == AV_CH_LAYOUT_5POINT0)
PICK_REORDER(50)
else if (layout == AV_CH_LAYOUT_5POINT1_BACK || layout == AV_CH_LAYOUT_5POINT1)
PICK_REORDER(51)
else if (layout == AV_CH_LAYOUT_7POINT1)
PICK_REORDER(71)
return s->reorder_func ? 0 : AVERROR(ENOSYS);
}
av_cold int ff_alsa_open(AVFormatContext *ctx, snd_pcm_stream_t mode,
unsigned int *sample_rate,
int channels, enum CodecID *codec_id)
@ -71,6 +193,7 @@ av_cold int ff_alsa_open(AVFormatContext *ctx, snd_pcm_stream_t mode,
snd_pcm_t *h;
snd_pcm_hw_params_t *hw_params;
snd_pcm_uframes_t buffer_size, period_size;
int64_t layout = ctx->streams[0]->codec->channel_layout;
if (ctx->filename[0] == 0) audio_device = "default";
else audio_device = ctx->filename;
@ -163,6 +286,21 @@ av_cold int ff_alsa_open(AVFormatContext *ctx, snd_pcm_stream_t mode,
snd_pcm_hw_params_free(hw_params);
if (channels > 2 && layout) {
if (find_reorder_func(s, *codec_id, layout, mode == SND_PCM_STREAM_PLAYBACK) < 0) {
char name[128];
av_get_channel_layout_string(name, sizeof(name), channels, layout);
av_log(ctx, AV_LOG_WARNING, "ALSA channel layout unknown or unimplemented for %s %s.\n",
name, mode == SND_PCM_STREAM_PLAYBACK ? "playback" : "capture");
}
if (s->reorder_func) {
s->reorder_buf_size = buffer_size;
s->reorder_buf = av_malloc(s->reorder_buf_size * s->frame_size);
if (!s->reorder_buf)
goto fail1;
}
}
s->h = h;
return 0;
@ -177,6 +315,7 @@ av_cold int ff_alsa_close(AVFormatContext *s1)
{
AlsaData *s = s1->priv_data;
av_freep(&s->reorder_buf);
snd_pcm_close(s->h);
return 0;
}
@ -201,3 +340,19 @@ int ff_alsa_xrun_recover(AVFormatContext *s1, int err)
}
return err;
}
int ff_alsa_extend_reorder_buf(AlsaData *s, int min_size)
{
int size = s->reorder_buf_size;
void *r;
av_assert0(size != 0);
while (size < min_size)
size *= 2;
r = av_realloc(s->reorder_buf, size * s->frame_size);
if (!r)
return AVERROR(ENOMEM);
s->reorder_buf = r;
s->reorder_buf_size = size;
return 0;
}

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@ -76,7 +76,15 @@ static int audio_write_packet(AVFormatContext *s1, AVPacket *pkt)
int size = pkt->size;
uint8_t *buf = pkt->data;
while((res = snd_pcm_writei(s->h, buf, size / s->frame_size)) < 0) {
size /= s->frame_size;
if (s->reorder_func) {
if (size > s->reorder_buf_size)
if (ff_alsa_extend_reorder_buf(s, size))
return AVERROR(ENOMEM);
s->reorder_func(buf, s->reorder_buf, size);
buf = s->reorder_buf;
}
while ((res = snd_pcm_writei(s->h, buf, size)) < 0) {
if (res == -EAGAIN) {
return AVERROR(EAGAIN);

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@ -47,6 +47,9 @@ typedef struct {
int period_size; ///< bytes per sample * channels
int sample_rate; ///< sample rate set by user
int channels; ///< number of channels set by user
void (*reorder_func)(const void *, void *, int);
void *reorder_buf;
int reorder_buf_size; ///< in frames
} AlsaData;
/**
@ -86,4 +89,6 @@ int ff_alsa_close(AVFormatContext *s1);
*/
int ff_alsa_xrun_recover(AVFormatContext *s1, int err);
int ff_alsa_extend_reorder_buf(AlsaData *s, int size);
#endif /* AVDEVICE_ALSA_AUDIO_H */