VIDEO: Add support for a track filtering callback function

This is needed for Starship Titanic, where videos can have a secondary
video track. It was simpler to use the callback as a means to select
one video track each across two decoders than trying to make VideoDecoder
and/or AVIDecoder support decoding from multiple video tracks simultaneously

2 files changed, 20 insertions, 10 deletions

diff --git a/video/avi_decoder.cpp b/video/avi_decoder.cpp
index 8f1bec4388..cb087c72fc 100644
--- a/video/avi_decoder.cpp
+++ b/video/avi_decoder.cpp
@@ -76,12 +76,13 @@ enum {
 };
 
 
-AVIDecoder::AVIDecoder(Audio::Mixer::SoundType soundType) : _frameRateOverride(0), _soundType(soundType) {
+AVIDecoder::AVIDecoder(Audio::Mixer::SoundType soundType, SelectTrackFn trackFn) : 
+		_frameRateOverride(0), _soundType(soundType), _selectTrackFn(trackFn) {
 	initCommon();
 }
 
-AVIDecoder::AVIDecoder(const Common::Rational &frameRateOverride, Audio::Mixer::SoundType soundType)
-		: _frameRateOverride(frameRateOverride), _soundType(soundType) {
+AVIDecoder::AVIDecoder(const Common::Rational &frameRateOverride, Audio::Mixer::SoundType soundType,
+		SelectTrackFn trackFn) : _frameRateOverride(frameRateOverride), _soundType(soundType), _selectTrackFn(trackFn) {
 	initCommon();
 }
 
@@ -99,6 +100,7 @@ void AVIDecoder::initCommon() {
 	_movieListStart = 0;
 	_movieListEnd = 0;
 	_fileStream = 0;
+	_videoTrackCounter = _audioTrackCounter = 0;
 	memset(&_header, 0, sizeof(_header));
 }
 
@@ -263,7 +265,8 @@ void AVIDecoder::handleStreamHeader(uint32 size) {
 			}
 		}
 
-		addTrack(new AVIVideoTrack(_header.totalFrames, sHeader, bmInfo, initialPalette));
+		if (!_selectTrackFn || _selectTrackFn(true, _videoTrackCounter++))
+			addTrack(new AVIVideoTrack(_header.totalFrames, sHeader, bmInfo, initialPalette));
 	} else if (sHeader.streamType == ID_AUDS) {
 		PCMWaveFormat wvInfo;
 		wvInfo.tag = _fileStream->readUint16LE();
@@ -278,9 +281,11 @@ void AVIDecoder::handleStreamHeader(uint32 size) {
 		if (wvInfo.channels == 2)
 			sHeader.sampleSize /= 2;
 
-		AVIAudioTrack *track = createAudioTrack(sHeader, wvInfo);
-		track->createAudioStream();
-		addTrack(track);
+		if (!_selectTrackFn || _selectTrackFn(false, _audioTrackCounter++)) {
+			AVIAudioTrack *track = createAudioTrack(sHeader, wvInfo);
+			track->createAudioStream();
+			addTrack(track);
+		}
 	}
 
 	// Ensure that we're at the end of the chunk
@@ -337,7 +342,6 @@ bool AVIDecoder::loadStream(Common::SeekableReadStream *stream) {
 	}
 
 	if (_videoTracks.size() != 1) {
-		warning("Unhandled AVI video track count: %d", _videoTracks.size());
 		close();
 		return false;
 	}
diff --git a/video/avi_decoder.h b/video/avi_decoder.h
index 96d9e821ff..04e6a1847e 100644
--- a/video/avi_decoder.h
+++ b/video/avi_decoder.h
@@ -61,8 +61,10 @@ namespace Video {
  */
 class AVIDecoder : public VideoDecoder {
 public:
-	AVIDecoder(Audio::Mixer::SoundType soundType = Audio::Mixer::kPlainSoundType);
-	AVIDecoder(const Common::Rational &frameRateOverride, Audio::Mixer::SoundType soundType = Audio::Mixer::kPlainSoundType);
+	typedef bool(*SelectTrackFn)(bool isVideo, int trackNumber);
+	AVIDecoder(Audio::Mixer::SoundType soundType = Audio::Mixer::kPlainSoundType, SelectTrackFn trackFn = nullptr);
+	AVIDecoder(const Common::Rational &frameRateOverride, Audio::Mixer::SoundType soundType = Audio::Mixer::kPlainSoundType,
+		SelectTrackFn trackFn = nullptr);
 	virtual ~AVIDecoder();
 
 	bool loadStream(Common::SeekableReadStream *stream);
@@ -268,6 +270,10 @@ protected:
 
 	Audio::Mixer::SoundType _soundType;
 	Common::Rational _frameRateOverride;
+
+	int _videoTrackCounter, _audioTrackCounter;
+	SelectTrackFn _selectTrackFn;
+
 	void initCommon();
 
 	bool parseNextChunk();