+ currentPts = (mtime_t)(1000000L / [sampleBuffer presentationTime].timeScale * [sampleBuffer presentationTime].timeValue);
+
+ /* Try to use hosttime of the sample if available, because iSight Pts seems broken */
+ NSNumber *hosttime = (NSNumber *)[sampleBuffer attributeForKey:QTSampleBufferHostTimeAttribute];
+ if( hosttime ) currentPts = (mtime_t)AudioConvertHostTimeToNanos([hosttime unsignedLongLongValue])/1000;