VIDEO: Allow for audio track selection in video types that support it

2 files changed, 100 insertions, 4 deletions

diff --git a/video/video_decoder.cpp b/video/video_decoder.cpp
index 0ab1478727..931bde20d0 100644
--- a/video/video_decoder.cpp
+++ b/video/video_decoder.cpp
@@ -46,6 +46,7 @@ VideoDecoder::VideoDecoder() {
 	_endTime = 0;
 	_endTimeSet = false;
 	_nextVideoTrack = 0;
+	_mainAudioTrack = 0;
 
 	// Find the best format for output
 	_defaultHighColorFormat = g_system->getScreenFormat();
@@ -75,6 +76,7 @@ void VideoDecoder::close() {
 	_endTime = 0;
 	_endTimeSet = false;
 	_nextVideoTrack = 0;
+	_mainAudioTrack = 0;
 }
 
 bool VideoDecoder::loadFile(const Common::String &filename) {
@@ -553,6 +555,9 @@ Audio::Timestamp VideoDecoder::FixedRateVideoTrack::getDuration() const {
 	return getFrameTime(getFrameCount());
 }
 
+VideoDecoder::AudioTrack::AudioTrack() : _volume(Audio::Mixer::kMaxChannelVolume), _balance(0), _muted(false) {
+}
+
 bool VideoDecoder::AudioTrack::endOfTrack() const {
 	Audio::AudioStream *stream = getAudioStream();
 	return !stream || !g_system->getMixer()->isSoundHandleActive(_handle) || stream->endOfData();
@@ -562,7 +567,7 @@ void VideoDecoder::AudioTrack::setVolume(byte volume) {
 	_volume = volume;
 
 	if (g_system->getMixer()->isSoundHandleActive(_handle))
-		g_system->getMixer()->setChannelVolume(_handle, _volume);
+		g_system->getMixer()->setChannelVolume(_handle, _muted ? 0 : _volume);
 }
 
 void VideoDecoder::AudioTrack::setBalance(int8 balance) {
@@ -578,7 +583,7 @@ void VideoDecoder::AudioTrack::start() {
 	Audio::AudioStream *stream = getAudioStream();
 	assert(stream);
 
-	g_system->getMixer()->playStream(getSoundType(), &_handle, stream, -1, getVolume(), getBalance(), DisposeAfterUse::NO);
+	g_system->getMixer()->playStream(getSoundType(), &_handle, stream, -1, _muted ? 0 : getVolume(), getBalance(), DisposeAfterUse::NO);
 
 	// Pause the audio again if we're still paused
 	if (isPaused())
@@ -597,7 +602,7 @@ void VideoDecoder::AudioTrack::start(const Audio::Timestamp &limit) {
 
 	stream = Audio::makeLimitingAudioStream(stream, limit, DisposeAfterUse::NO);
 
-	g_system->getMixer()->playStream(getSoundType(), &_handle, stream, -1, getVolume(), getBalance(), DisposeAfterUse::YES);
+	g_system->getMixer()->playStream(getSoundType(), &_handle, stream, -1, _muted ? 0 : getVolume(), getBalance(), DisposeAfterUse::YES);
 
 	// Pause the audio again if we're still paused
 	if (isPaused())
@@ -611,6 +616,16 @@ uint32 VideoDecoder::AudioTrack::getRunningTime() const {
 	return 0;
 }
 
+void VideoDecoder::AudioTrack::setMute(bool mute) {
+	// Update the mute settings, if required
+	if (_muted != mute) {
+		_muted = mute;
+
+		if (g_system->getMixer()->isSoundHandleActive(_handle))
+			g_system->getMixer()->setChannelVolume(_handle, mute ? 0 : _volume);
+	}
+}
+
 void VideoDecoder::AudioTrack::pauseIntern(bool shouldPause) {
 	if (g_system->getMixer()->isSoundHandleActive(_handle))
 		g_system->getMixer()->pauseHandle(_handle, shouldPause);
@@ -669,6 +684,17 @@ void VideoDecoder::addTrack(Track *track, bool isExternal) {
 		// Update volume settings if it's an audio track
 		((AudioTrack *)track)->setVolume(_audioVolume);
 		((AudioTrack *)track)->setBalance(_audioBalance);
+
+		if (!isExternal && supportsAudioTrackSwitching()) {
+			if (_mainAudioTrack) {
+				// The main audio track has already been found
+				((AudioTrack *)track)->setMute(true);
+			} else {
+				// First audio track found -> now the main one
+				_mainAudioTrack = (AudioTrack *)track;
+				_mainAudioTrack->setMute(false);
+			}
+		}
 	} else if (track->getTrackType() == Track::kTrackTypeVideo) {
 		// If this track has a better time, update _nextVideoTrack
 		if (!_nextVideoTrack || ((VideoTrack *)track)->getNextFrameStartTime() < _nextVideoTrack->getNextFrameStartTime())
@@ -701,6 +727,34 @@ bool VideoDecoder::addStreamFileTrack(const Common::String &baseName) {
 	return result;
 }
 
+bool VideoDecoder::setAudioTrack(int index) {
+	if (!supportsAudioTrackSwitching())
+		return false;
+
+	AudioTrack *audioTrack = getAudioTrack(index);
+
+	if (!audioTrack)
+		return false;
+
+	if (_mainAudioTrack == audioTrack)
+		return true;
+
+	_mainAudioTrack->setMute(true);
+	audioTrack->setMute(false);
+	_mainAudioTrack = audioTrack;
+	return true;
+}
+
+uint VideoDecoder::getAudioTrackCount() const {
+	uint count = 0;
+
+	for (TrackList::const_iterator it = _internalTracks.begin(); it != _internalTracks.end(); it++)
+		if ((*it)->getTrackType() == Track::kTrackTypeAudio)
+			count++;
+
+	return count;
+}
+
 void VideoDecoder::setEndTime(const Audio::Timestamp &endTime) {
 	Audio::Timestamp startTime = 0;
 
diff --git a/video/video_decoder.h b/video/video_decoder.h
index ac6586d8dd..99161d6f97 100644
--- a/video/video_decoder.h
+++ b/video/video_decoder.h
@@ -407,6 +407,21 @@ public:
 	 */
 	bool addStreamFileTrack(const Common::String &baseName);
 
+	/**
+	 * Set the internal audio track.
+	 *
+	 * Has no effect if the container does not support this.
+	 * @see supportsAudioTrackSwitching()
+	 *
+	 * @param index The index of the track, whose meaning is dependent on the container
+	 */
+	bool setAudioTrack(int index);
+
+	/**
+	 * Get the number of internal audio tracks.
+	 */
+	uint getAudioTrackCount() const;
+
 protected:
 	/**
 	 * An abstract representation of a track in a movie. Since tracks here are designed
@@ -612,7 +627,7 @@ protected:
 	 */
 	class AudioTrack : public Track {
 	public:
-		AudioTrack() {}
+		AudioTrack();
 		virtual ~AudioTrack() {}
 
 		TrackType getTrackType() const { return kTrackTypeAudio; }
@@ -662,6 +677,11 @@ protected:
 		 */
 		virtual Audio::Mixer::SoundType getSoundType() const { return Audio::Mixer::kPlainSoundType; }
 
+		/**
+		 * Mute the track
+		 */
+		void setMute(bool mute);
+
 	protected:
 		void pauseIntern(bool shouldPause);
 
@@ -674,6 +694,7 @@ protected:
 		Audio::SoundHandle _handle;
 		byte _volume;
 		int8 _balance;
+		bool _muted;
 	};
 
 	/**
@@ -833,6 +854,25 @@ protected:
 	 */
 	virtual bool seekIntern(const Audio::Timestamp &time);
 
+	/**
+	 * Does this video format support switching between audio tracks?
+	 *
+	 * Returning true implies this format supports multiple audio tracks,
+	 * can switch tracks, and defaults to playing the first found audio
+	 * track.
+	 */
+	virtual bool supportsAudioTrackSwitching() const { return false; }
+
+	/**
+	 * Get the audio track for the given index.
+	 *
+	 * This is used only if supportsAudioTrackSwitching() returns true.
+	 *
+	 * @param index The index of the track, whose meaning is dependent on the container
+	 * @return The audio track for the index, or 0 if not found
+	 */
+	virtual AudioTrack *getAudioTrack(int index) { return 0; }
+
 private:
 	// Tracks owned by this VideoDecoder
 	TrackList _tracks;
@@ -865,6 +905,8 @@ private:
 	uint32 _pauseStartTime;
 	byte _audioVolume;
 	int8 _audioBalance;
+
+	AudioTrack *_mainAudioTrack;
 };
 
 } // End of namespace Video