Proper lag calculation even if the SMK has no audio

svn-id: r35698

2 files changed, 16 insertions, 2 deletions

diff --git a/graphics/video/smk_player.cpp b/graphics/video/smk_player.cpp
index 2ea9fe7e44..5ad7044c5f 100644
--- a/graphics/video/smk_player.cpp
+++ b/graphics/video/smk_player.cpp
@@ -370,12 +370,22 @@ int32 SMKPlayer::getFrameDelay() {
 }
 
 int32 SMKPlayer::getAudioLag() {
-	if (!_fileStream || !_audioStream)
+	if (!_fileStream)
 		return 0;
 
 	int32 frameDelay = getFrameDelay();
 	int32 videoTime = _currentSMKFrame * frameDelay;
-	int32 audioTime = (((int32) _mixer->getSoundElapsedTime(_audioHandle)) * 100);
+	int32 audioTime;
+
+	if (!_audioStream) {
+		/* 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() - _startTime) * 100;
+	} else
+		audioTime = (((int32) _mixer->getSoundElapsedTime(_audioHandle)) * 100);
 
 	return videoTime - audioTime;
 }
@@ -546,6 +556,9 @@ bool SMKPlayer::decodeNextFrame() {
 
 	uint32 startPos = _fileStream->pos();
 
+	if (_currentSMKFrame == 0)
+		_startTime = g_system->getMillis();
+
 	// Check if we got a frame with palette data, and
 	// call back the virtual setPalette function to set
 	// the current palette
diff --git a/graphics/video/smk_player.h b/graphics/video/smk_player.h
index e07412b2a5..c1b118b13e 100644
--- a/graphics/video/smk_player.h
+++ b/graphics/video/smk_player.h
@@ -184,6 +184,7 @@ private:
 	Audio::SoundHandle _audioHandle;
 
 	uint32 _currentSMKFrame;
+	uint32 _startTime;
 
 	BigHuffmanTree *_MMapTree;
 	BigHuffmanTree *_MClrTree;