diff --git a/libavdevice/alsa-audio-common.c b/libavdevice/alsa-audio-common.c index 38cb0de0ef..4edd25bcd7 100644 --- a/libavdevice/alsa-audio-common.c +++ b/libavdevice/alsa-audio-common.c @@ -43,6 +43,59 @@ static av_cold snd_pcm_format_t codec_id_to_pcm_format(int codec_id) } } +static void alsa_reorder_s16_out_51(const void *in_v, void *out_v, int n) +{ + const int16_t *in = in_v; + int16_t *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; + } +} + +static void alsa_reorder_s16_out_71(const void *in_v, void *out_v, int n) +{ + const int16_t *in = in_v; + int16_t *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; + } +} + +#define REORDER_DUMMY ((void *)1) + +static av_cold ff_reorder_func find_reorder_func(int codec_id, + int64_t layout, + int out) +{ + return + codec_id == CODEC_ID_PCM_S16LE || codec_id == CODEC_ID_PCM_S16BE ? + layout == AV_CH_LAYOUT_QUAD ? REORDER_DUMMY : + layout == AV_CH_LAYOUT_5POINT1_BACK ? + out ? alsa_reorder_s16_out_51 : NULL : + layout == AV_CH_LAYOUT_7POINT1 ? + out ? alsa_reorder_s16_out_71 : NULL : + NULL : + NULL; +} + av_cold int ff_alsa_open(AVFormatContext *ctx, snd_pcm_stream_t mode, unsigned int *sample_rate, int channels, enum CodecID *codec_id) @@ -54,6 +107,7 @@ 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; @@ -146,6 +200,26 @@ av_cold int ff_alsa_open(AVFormatContext *ctx, snd_pcm_stream_t mode, snd_pcm_hw_params_free(hw_params); + if (channels > 2 && layout) { + s->reorder_func = find_reorder_func(*codec_id, layout, + mode == SND_PCM_STREAM_PLAYBACK); + if (s->reorder_func == REORDER_DUMMY) { + s->reorder_func = NULL; + } else 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; + } else { + char name[16]; + 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"); + } + } + s->h = h; return 0; @@ -160,6 +234,7 @@ 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; } @@ -184,3 +259,18 @@ 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; + + 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; +} diff --git a/libavdevice/alsa-audio-enc.c b/libavdevice/alsa-audio-enc.c index 83a179ecfe..0bc53b6f54 100644 --- a/libavdevice/alsa-audio-enc.c +++ b/libavdevice/alsa-audio-enc.c @@ -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); diff --git a/libavdevice/alsa-audio.h b/libavdevice/alsa-audio.h index 949383157e..8c7c516585 100644 --- a/libavdevice/alsa-audio.h +++ b/libavdevice/alsa-audio.h @@ -39,10 +39,15 @@ other formats */ #define DEFAULT_CODEC_ID AV_NE(CODEC_ID_PCM_S16BE, CODEC_ID_PCM_S16LE) +typedef void (*ff_reorder_func)(const void *, void *, int); + typedef struct { snd_pcm_t *h; int frame_size; ///< preferred size for reads and writes int period_size; ///< bytes per sample * channels + ff_reorder_func reorder_func; + void *reorder_buf; + int reorder_buf_size; ///< in frames } AlsaData; /** @@ -82,4 +87,6 @@ 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 */