VideoHelp Forum
+ Reply to Thread
Results 1 to 2 of 2
Thread
  1. Hey Guys,

    I used good encoding settings using CRF, the quality is good most of the times.

    But sometimes bitrate goes very low and the quality turns out bad. So here is what i want to do, to use minrate at all times. No matter what the video is the minimum bitrate should be 900kbps. Can i achieve that?

    hanks
    Quote Quote  
  2. Member
    Join Date
    Aug 2013
    Location
    Central Germany
    Search PM
    That's not possible as you describe it, because the goal of an encoder is efficiency, and it won't waste bitrate on scenes with content which is very easy to compress (let's say, stills or even black screens). Why would you waste 900 kbps on black screens when the codec is satisfied with a fraction of that to preserve as much quality as necessary, for its metrics? You don't lose quality in specific scenes only by low bitrate, but rather by the codec rating this scene as "too unimportant" to spend more on this scene, simplified.

    If there is bad quality in a few scenes, check first if the quality is not already as bad in the original material there; then, let's check if there are ways to shift bitrate distribution towards the characteristics of such scenes a bit (but in general, it will probably require decreasing your RF and limiting the upper bounds instead, e.g. with VBV parameters). Samples would be helpful to understand your specific case (including your current complete command line parameter set).

    After all, are you sure that the loss of quality actually happens in scenes with a low bitrate? Did you display the current bitrate anywhere while watching it?
    Quote Quote  



Similar Threads

Visit our sponsor! Try DVDFab and backup Blu-rays!