AUDIO: Fix M4A seeking with multiple time->sample chunks

1 files changed, 16 insertions, 9 deletions

diff --git a/audio/decoders/quicktime.cpp b/audio/decoders/quicktime.cpp
index 621964cb3b..dcf80ea1c6 100644
--- a/audio/decoders/quicktime.cpp
+++ b/audio/decoders/quicktime.cpp
@@ -230,16 +230,23 @@ void QuickTimeAudioDecoder::setAudioStreamPos(const Timestamp &where) {
 	uint32 seekSample = sample;
 
 	if (!isOldDemuxing()) {
-		// We shouldn't have audio samples that are a different duration
-		// That would be quite bad!
-		if (_tracks[_audioTrackIndex]->timeToSampleCount != 1) {
-			warning("Failed seeking");
-			return;
-		}
+		// For MPEG-4 style demuxing, we need to track down the sample based on the time
+		// The old style demuxing doesn't require this because each "sample"'s duration
+		// is just 1
+		uint32 curSample = 0;
+		seekSample = 0;
+
+		for (int32 i = 0; i < _tracks[_audioTrackIndex]->timeToSampleCount; i++) {
+			uint32 sampleCount = _tracks[_audioTrackIndex]->timeToSample[i].count * _tracks[_audioTrackIndex]->timeToSample[i].duration;
+
+			if (sample < curSample + sampleCount) {
+				seekSample += (sample - curSample) / _tracks[_audioTrackIndex]->timeToSample[i].duration;
+				break;
+			}
 
-		// Note that duration is in terms of *one* channel
-		// This eases calculation a bit
-		seekSample /= _tracks[_audioTrackIndex]->timeToSample[0].duration;
+			seekSample += _tracks[_audioTrackIndex]->timeToSample[i].count;
+			curSample += sampleCount;
+		}
 	}
 
 	// Now to track down what chunk it's in