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(API Change) Add support for multiple audio mixers

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API changed:
--------------------------

void obs_output_set_audio_encoder(
		obs_output_t *output,
		obs_encoder_t *encoder);

obs_encoder_t *obs_output_get_audio_encoder(
		const obs_output_t *output);

obs_encoder_t *obs_audio_encoder_create(
		const char *id,
		const char *name,
		obs_data_t *settings);

Changed to:
--------------------------

/* 'idx' specifies the track index of the output */
void obs_output_set_audio_encoder(
		obs_output_t *output,
		obs_encoder_t *encoder,
		size_t idx);

/* 'idx' specifies the track index of the output */
obs_encoder_t *obs_output_get_audio_encoder(
		const obs_output_t *output,
		size_t idx);

/* 'mixer_idx' specifies the mixer index to capture audio from */
obs_encoder_t *obs_audio_encoder_create(
		const char *id,
		const char *name,
		obs_data_t *settings,
		size_t mixer_idx);

Overview
--------------------------
This feature allows multiple audio mixers to be used at a time.  This
capability was able to be added with surprisingly very little extra
overhead.  Audio will not be mixed unless it's assigned to a specific
mixer, and mixers will not mix unless they have an active mix
connection.

Mostly this will be useful for being able to separate out specific audio
for recording versus streaming, but will also be useful for certain
streaming services that support multiple audio streams via RTMP.

I didn't want to use a variable amount of mixers due to the desire to
reduce heap allocations, so currently I set the limit to 4 simultaneous
mixers; this number can be increased later if needed, but honestly I
feel like it's just the right number to use.

Sources:

Sources can now specify which audio mixers their audio is mixed to; this
can be a single mixer or multiple mixers at a time.  The
obs_source_set_audio_mixers function sets the audio mixer which an audio
source applies to.  For example, 0xF would mean that the source applies
to all four mixers.

Audio Encoders:

Audio encoders now must specify which specific audio mixer they use when
they encode audio data.

Outputs:

Outputs that use encoders can now support multiple audio tracks at once
if they have the OBS_OUTPUT_MULTI_TRACK capability flag set.  This is
mostly only useful for certain types of RTMP transmissions, though may
be useful for file formats that support multiple audio tracks as well
later on.
This commit is contained in:
jp9000
2015-01-14 02:12:08 -08:00
parent e4fdd61c74
commit 84e1f47ced
17 changed files with 513 additions and 151 deletions
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20
libobs/media-io/audio-io.h
View File

@@ -24,6 +24,8 @@
extern "C" {
#endif
#define MAX_AUDIO_MIXES 4
/*
* Base audio output component. Use this to create an audio output track
* for the media.
@@ -172,13 +174,14 @@ static inline size_t get_audio_size(enum audio_format format,
EXPORT int audio_output_open(audio_t **audio, struct audio_output_info *info);
EXPORT void audio_output_close(audio_t *audio);
EXPORT bool audio_output_connect(audio_t *video,
typedef void (*audio_output_callback_t)(void *param, size_t mix_idx,
struct audio_data *data);
EXPORT bool audio_output_connect(audio_t *video, size_t mix_idx,
const struct audio_convert_info *conversion,
void (*callback)(void *param, struct audio_data *data),
void *param);
EXPORT void audio_output_disconnect(audio_t *video,
void (*callback)(void *param, struct audio_data *data),
void *param);
audio_output_callback_t callback, void *param);
EXPORT void audio_output_disconnect(audio_t *video, size_t mix_idx,
audio_output_callback_t callback, void *param);
EXPORT bool audio_output_active(const audio_t *audio);
@@ -189,7 +192,10 @@ EXPORT uint32_t audio_output_get_sample_rate(const audio_t *audio);
EXPORT const struct audio_output_info *audio_output_get_info(
const audio_t *audio);
EXPORT audio_line_t *audio_output_create_line(audio_t *audio, const char *name);
EXPORT audio_line_t *audio_output_create_line(audio_t *audio, const char *name,
uint32_t mixers);
EXPORT void audio_line_set_mixers(audio_line_t *line, uint32_t mixers);
EXPORT uint32_t audio_line_get_mixers(audio_line_t *line);
EXPORT void audio_line_destroy(audio_line_t *line);
EXPORT void audio_line_output(audio_line_t *line, const struct audio_data *data);