Backward set position problem

[Smelena]

I use DirectShow in my application for playback of .wmv files on Windows CE
5.0 station. Duration of each file is 20-23 seconds. When I change slider
position backward on position <7 seconds and call SetPosition function of
IMediaSeeking interface, video is freezing for a second and then starts from
7 seconds (always). GetPosition function returns 7 seconds (after
SetPosition(<7) calling). Will appreciate if someone knows and can share
knowledge on how I can fix or workaround this issue.
Thank you

[Saad_Aomata]

Smelena,

How far apart the key frames are in these media file. Chances are that after
the initial keyframe in the beginning of the file, there is no keyframe for
the next 7 seconds. When you seek, the source filter will seek to the
corresponding position in the media file and keep on discarding packets till
it encounters a key frame. From that point onwards it starts delivering the
data for codecs to decode and video renderer to render.

If you generate the media files yourself, you should try to have key frames
no more than 1 second apart.

Thanks
Saad Puri
AOMATA LLC. | www.aomataconsulting.com