Override getAudioLag() in the AviDecoder (blatantly borrowed from the SmackerDecoder).

svn-id: r45172

2 files changed, 23 insertions, 1 deletions

diff --git a/graphics/video/avi_decoder.cpp b/graphics/video/avi_decoder.cpp
index fa5494d9b9..a3180edeee 100644
--- a/graphics/video/avi_decoder.cpp
+++ b/graphics/video/avi_decoder.cpp
@@ -361,6 +361,27 @@ bool AviDecoder::decodeNextFrame() {
 	return _videoInfo.currentFrame < _videoInfo.frameCount;
 }
 
+int32 AviDecoder::getAudioLag() {
+	if (!_fileStream)
+		return 0;
+
+	int32 frameDelay = getFrameDelay();
+	int32 videoTime = _videoInfo.currentFrame * frameDelay;
+	int32 audioTime;
+
+	if (!_audStream) {
+		/* No audio.
+		   Calculate the lag by how much time has gone by since the first frame
+		   and how much time *should* have passed.
+		*/
+
+		audioTime = (g_system->getMillis() - _videoInfo.startTime) * 100;
+	} else
+		audioTime = (((int32)_mixer->getSoundElapsedTime(*_audHandle)) * 100);
+
+	return videoTime - audioTime;
+}
+
 Codec *AviDecoder::createCodec() {
 	switch (_vidsHeader.streamHandler) {
 		case ID_CRAM:
diff --git a/graphics/video/avi_decoder.h b/graphics/video/avi_decoder.h
index 85500302d0..bfeab02346 100644
--- a/graphics/video/avi_decoder.h
+++ b/graphics/video/avi_decoder.h
@@ -188,8 +188,9 @@ public:
 	void closeFile();
 
 	bool decodeNextFrame();
-
+	int32 getAudioLag();
 	int32 getFrameRate() { return _vidsHeader.rate / _vidsHeader.scale; }
+
 private:
 	Audio::Mixer *_mixer;
 	BITMAPINFOHEADER _bmInfo;