Results 1 to 7 of 7

Thread: paq8px Model For Video Compression

  1. #1
    Member
    Join Date
    Nov 2014
    Location
    China
    Posts
    11
    Thanks
    3
    Thanked 0 Times in 0 Posts

    paq8px Model For Video Compression

    Hi,all.

    I'm new to paq8px's models and I'm just wondering if there is any video model for paq8px that can do some inter-frame prediction like h264/h265 does.

    I think it would use some surrounding pixels in previous frame to predict pixels in current frames in the same position and combined with current image24 model,may it outperform h265 in lossless video compression.

  2. #2
    Member
    Join Date
    Aug 2009
    Location
    Russia, moscow
    Posts
    12
    Thanks
    0
    Thanked 0 Times in 0 Posts
    With same speed?

  3. #3
    Member
    Join Date
    Aug 2014
    Location
    Argentina
    Posts
    464
    Thanks
    202
    Thanked 81 Times in 61 Posts
    Quote Originally Posted by davidwjx View Post
    I'm just wondering if there is any video model for paq8px that can do some inter-frame prediction like h264/h265 does.
    The answer is no. But the idea is interesting...



    Quote Originally Posted by Pedofinder View Post
    With same speed?
    Not, a paq model is never intended for high speed. It would be insane to try implementing it at hardware level.
    So it can't ever be considered as proper codec. But, if possible, the compression will be great.
    Of course you have to deal with uncompressed video only. A re-compressor for, let's say, ffmpeg, needs from a more elaborated process.
    Last edited by Gonzalo; 25th November 2014 at 23:04.

  4. The Following User Says Thank You to Gonzalo For This Useful Post:

    davidwjx (26th November 2014)

  5. #4
    Member
    Join Date
    Nov 2014
    Location
    China
    Posts
    11
    Thanks
    3
    Thanked 0 Times in 0 Posts
    I have written this code from scrach,but I don't know how to use SmallStationaryContextMap like other models, any idea? Thanks

    Code:
    //////////////////////////// videoModel /////////////////////////////////
    // Model for 24-bit image data
    class videoModel: public Model {
     const int SearchRange;//search in SearchRange*SearchRange macroblock
     
     ContextMap cm;
     BlockData& x;
     Buf& buf;
    public:
    
      videoModel(BlockData& bd): SearchRange(8), cm(CMlimit(MEM()*4), SearchRange*SearchRange),x(bd),buf(bd.buf) {
           
      }
      int p(Mixer& m,int frameSizeInByte,int stride){//stride : number of bytes per line
        if (!x.bpos) {
            
            for(int hoffset = -1*SearchRange; hoffset < SearchRange ; hoffset ++)
            {
                for(int woffset = -1*SearchRange ; woffset < SearchRange ; woffset ++)
                {
                    int pos = frameSizeInByte + hoffset * stride + woffset*3; // just for rgb24 color plane
                    cm.set(buf(frameSizeInByte+Stride));
                }
            }
        }
        cm.mix(m);
        m.set(0, SearchRange*SearchRange);
        return 0;
      }
      
      ~videoModel(){ }
     
    };

  6. #5
    Member
    Join Date
    Nov 2014
    Location
    China
    Posts
    11
    Thanks
    3
    Thanked 0 Times in 0 Posts
    Quote Originally Posted by Pedofinder View Post
    With same speed?
    Not, for certain circumstance,speed is not much the matter, but space is.

    For examples,there are hundreds of thousands of similar images grabbed from camera sensor in industry,and the images should stay losslessly for years.
    In this enviroment,losslessly image compression is simplely not enough,because the inter-image redundance is still out there.

  7. #6
    Member
    Join Date
    Aug 2009
    Location
    Russia, moscow
    Posts
    12
    Thanks
    0
    Thanked 0 Times in 0 Posts
    If need to reduce size, peoples usially look for lossy codecs, and preferably by hardware encode devices. Don't waste you're time if it is not hobby.

  8. #7
    Member
    Join Date
    Nov 2014
    Location
    China
    Posts
    11
    Thanks
    3
    Thanked 0 Times in 0 Posts
    Quote Originally Posted by Pedofinder View Post
    If need to reduce size, peoples usially look for lossy codecs, and preferably by hardware encode devices. Don't waste you're time if it is not hobby.
    Thanks,and indeed it's about hobby.

    I have tried it, but it doesn't seem work.

Similar Threads

  1. user - video compression.
    By WebWalker in forum Data Compression
    Replies: 15
    Last Post: 8th July 2013, 17:13
  2. Question - Video Compression
    By HeRo in forum Data Compression
    Replies: 5
    Last Post: 23rd September 2012, 21:09
  3. Video compression without the need for playback
    By david_werecat in forum Data Compression
    Replies: 8
    Last Post: 19th September 2011, 12:01
  4. PAQ8PX for Mac OS X?
    By Shoal in forum Data Compression
    Replies: 11
    Last Post: 8th July 2011, 17:35
  5. video compression (test)
    By Lone_Wolf in forum Data Compression
    Replies: 42
    Last Post: 14th January 2010, 23:50

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •