======Decoder options======

=====Libavcodec options=====

====IDCT====
MPEG videos are encoded using certain [[wp>Discrete_cosine_transform|DCT]] algorithms. IDCT is the inverse process of DCT. The IDCT algorithm must match the one that was used to encode the video. If libavcodec's auto detection fails for some reason, the proper IDCT can be selected here manually.

====Number of decoding threads====
MPEG-1/2 and H.264 decoders are multithreaded and thus benefit from multi-core CPUs. The number of cores is automatically detected during ffdshow setup but can be configured here subsequently.

====Detect soft telecine and average frame durations====
Unless your output device is a interlaced TV, keep this checked. Some movies may have alternate frame duration (2:3) due to [[http://en.wikipedia.org/wiki/Telecine|telecine]]. With this option enabled, ffdshow averages frame duration for smooth playback.

====Workaround encoder bugs====
ToDo

=====Quality control=====

====Drop frame on delay====
This option defines a threshold after which ffdshow will start dropping frames to get audio and video back in sync. Out-of-sync issues usually occur when the CPU can't manage its workload.

====Skip H264 deblocking on delay====
With this option enabled, ffdshow will skip the [[wp>Deblocking_filter_(video)|H.264 deblocking filter]] and try to re-sync if the video is delayed.
Skipping the deblocking filter can decrease the video quality though.