Change FPS rate/scale ratio

Discussion in 'Other video questions' started by newpath, Nov 17, 2008.

  1. newpath

    newpath Member

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    I posted this message in the VideoHelp forum, but have had no responses, so I though I would try here. I apologize for the cross-posting.

    As many of you may know, the Hauppauge HD PVR produces some nice looking recordings from HD cable or satellite. However, the file format is a bit odd in that the files are difficult to edit and/or re-encode. I have been trying to come up with an effective and reproducible method for re-encoding the H.264 recorded files with a lower bitrate to reduce file size. It has not been consistent. I have been reading about frame rates and how they are computed within a video stream using a rate and scale: fps = rate/scale. The HD PVR produces H.264 streams with very odd rate/scale ratios. For example, a recording I made of CSI in HD had rate = 10000000 and scale = 166833 for 10000000/166833 = 59.9401797. As I understand it, these odd ratios can adversely affect playback and seeking with some software players. Hence, I would like to change the ration to 60000/1001 = 59.94005994.

    I have been working with x264 and DivX264 to re-encode my HD PVR recordings, but I cannot seem to change the rate/scale ratio using either encoder. Using the parameter --fps 60000/1001 does not change the ratio in the recorded file. Can anyone help me to determine if the rate/scale ratio can be changed and, if so, how? In addition, if I am incorrect in my assumptions or following a dead-end, let me know. Any help would be appreciated.
     
  2. attar

    attar Senior member

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  3. newpath

    newpath Member

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    Excellent idea, attar. I am already registered at Doom9 so the message is there. Thanks.
     

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