DefaultAudioMixer

public int addSource(AudioProcessor.AudioFormat sourceFormat, long startTimeUs)

Adds an audio source to mix starting at the given time.

If the mixer has already output samples past the startTimeUs, audio from this source will be discarded up to the last output end timestamp.

If the source start time is earlier than the configured mixer start time then audio from this source will be discarded up to the mixer start time.

All audio sources start with a volume of 1.0 on all channels.

public void configure(
    AudioProcessor.AudioFormat outputAudioFormat,
    int bufferSizeMs,
    long startTimeUs
)

Configures the mixer.

The mixer must be configured before use and can only be reconfigured after a call to reset.

The mixing buffer size is set by bufferSizeMs and indicates how much audio can be queued before getOutput is called.

public ByteBuffer getOutput()

Returns a buffer containing output audio data between its position and limit.

The buffer will be no larger than the configured buffer size and will include no more than the frames that have been queued from all sources, up to the end time. Silence will be generated for any periods with no sources.

The buffer will always be a direct byte buffer with native byte order. Calling this method invalidates any previously returned buffer. The buffer will be empty if no output is available.

public boolean hasSource(int sourceId)

Returns whether there is an added source with the given sourceId.

public boolean isEnded()

Returns whether the mixer can accept more input or produce more output, based on the end time.

Note: If no end time is set this will always return false.

public void queueInput(int sourceId, ByteBuffer sourceBuffer)

Queues audio data between the position and limit of the sourceBuffer.

After calling this method output may be available via getOutput if all sources have queued data.

public void removeSource(int sourceId)

Removes an audio source.

No more audio can be queued from this source. All audio queued before removal will be output.

public void reset()

Resets the mixer to its unconfigured state, releasing any resources.

public void setEndTimeUs(long endTimeUs)

Sets the end time of the output audio.

The mixer will not accept input nor produce output past this point.

public void setSourceVolume(int sourceId, float volume)

Sets the volume applied to future samples queued from the given source.

public boolean supportsSourceAudioFormat(AudioProcessor.AudioFormat sourceFormat)

Indicates whether the mixer supports mixing sources with the given audio format.