locked
About WMV encoding RRS feed

  • Question

  • I have some problems of wmv encoding now,

     

    It is this, I've encoding some BMP of 24bit to the wmv file.

     

    there is 600 image files and i encoded to a five seconds wmv file as 120 frame per second.

     

    the bitrate i set is 300KB and the KeyFrametimespacing is 0.5 second, and the wmv file's size is 1280*480.

     

    it encoded ,

     

    But when i played the file,  It look like 10 frames per second,

     

    so I increased the bitrate as 7000KB and the wmv file look like 80 frames per second,

     

    what problem of the above?

     

    if the bitrate i set is too small for 1280* 480 size or for 120 frame per second? so the codec auto changed the frames?

     

    for helps, thanks.

    Wednesday, July 9, 2008 5:43 AM

Answers

  • I'm going to guess that the WMV encoder just isn't outputting a frame for every input frame you give it.  By default, it's free to do that; it might be skipping output frames to stay under the bitrate you gave it.

     

    If you need to, there is an option that requires the WMV encoder to output a frame for every input frame.  To enable this option in the WMFSDK, call IWMWriterAdvanced:Tongue TiedetInputSetting with the g_wszFixedFrameRate (set it to TRUE)

    Wednesday, July 9, 2008 11:38 PM