The VideoLAN Forums

When using GPU acceleration on Win7, corruption/pixellation occurs immediately after seeking.

It looks like macroblocks are getting screwed up. For example you can see the outline of a person/object but they are filled in with macroblocks from a different frame. Other times it just looks like some blocking/pixellation around the frame.

The corruption fixes itself on the next keyframe. With some encoded x264 content this can take several seconds so it looks pretty screwy.

Win7 x64
VLC 2.0.1 (both 32-bit and 64-bit)
Nvidia GPU
MKVs using x264

For example you can see the outline of a person/object but they are filled in with macroblocks from a different frame.
The corruption fixes itself on the next keyframe.

Well, that does make sense to me, especially with B-frames.

Well, that does make sense to me, especially with B-frames.

Actually, if the original poster has the same problem as me, it doesn't make sense. I get the same symptoms as described, but one detail is that the first frame after seeking is actually displayed correctly, and only all subsequent frames until the next keyframe get corrupted. It seems that the frame I seek to is correctly reconstructed, but the subsequent delta information is applied to an older frame from before the seek, which is apparently still kept in a buffer somewhere.

Seeking to non-I-frames shouldn't lead to corruption. I don't know how it is usually handled, whether through buffering and/or just decompressing as many frames as needed, but it should be avoided. Software decoders manage, so there's no reason why hardware decoders shouldn't.

Also, while I'm not sure whether an update of VLC or nVIDIA drivers caused the issue, I'd note that I do not get these corruption artifacts when seeking through the same video files on MPC-HC or WMP, which both use hardware decoding as well. I have updated to the lastest nVIDIA drivers and the latest stable version of VLC, to no effect.