VideoHelp Forum

Try DVDFab and download streaming video, copy, convert or make Blu-rays,DVDs! Download free trial !
+ Reply to Thread
Results 1 to 5 of 5
Thread
  1. Is it right that that the rendering engine will make a difference?

    Let's assume a video editing program where i have introduced a title and a few transitions on the clip cuts on an mp4 video.

    I run this through the smart re-encoding feature of the program which only re-encodes the manipulated portions of the video v/s rendering it with full re-encoding (not using smart render feature) - How much decrease in quality would there be and is this quantifiable (apart from trusting the naked eye)?

    Would just like to understand te concept and what i am losing out on by not having a smart render feature in my editor!

    Thanks experts at Videohelp
    Quote Quote  
  2. Dinosaur Supervisor KarMa's Avatar
    Join Date
    Jul 2015
    Location
    US
    Search Comp PM
    Anytime you re-encode with a lossy codec, it is going to lose some quality. Even at the same bitrate. I have no way of quantifying it as it just depends on how good the codec is and what settings you used and how complex the content is (movement).
    Quote Quote  
  3. Ooops i did not make myself clear

    I meant if i used the same codec (eg mp4 x264) and the output after a few edits was also the same (mp4 x264) then what??
    Quote Quote  
  4. Member Cornucopia's Avatar
    Join Date
    Oct 2001
    Location
    Deep in the Heart of Texas
    Search PM
    Same answer.
    Smart rendering means copying that clip segment (if possible) vs re-encoding. So lossless vs lossy. Sometimes lossy isn't noticeably worse, sometimes it is. The underlying pixels ARE always degraded, though.

    You could run a few tests and compare at certain bitrates using psnr or something as a quantitative objective measure, but it's always ultimately a qualitative judgement call, which is mainly subjective.

    Scott
    Quote Quote  
  5. In theory the "smart rendered" version may be of somewhat higher quality, due to not having to re-encode the whole file.

    Just curious, are you working with Pegasys' software?
    Quote Quote  



Similar Threads