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• libx265 motion compensation and CU traverse

  17 juin 2016, par Ariana

  I’m trying to play with the H.265 motion compensation and search (HEVC- libx265 implementation from here : https://bitbucket.org/multicoreware/x265/downloads). I need to slightly extend the edge extension search, and fill the macro block with left-most pixels as if my sample videos are like cylinder (rightmost is connected to leftmost).

  What I need to do is basically this :

  

  One way to do that is to modify the edge extension area (which is already in the code, in the frameFilter.cpp), and do that for rightmost and fill parts of blocks which are out with leftmost pixels. I identified the piece of code here which apparently is responsible for that. Can someone help me with implementing this feature ?

  if ((col == 0) | (col == m_frameFilter->m_numCols - 1))
  
      {
  
          // TODO: improve by process on Left or Right only
  
          primitives.extendRowBorder(reconPic->getLumaAddr(m_rowAddr), stride, reconPic->m_picWidth, realH, reconPic->m_lumaMarginX);
  
  
  
          if (m_frameFilter->m_param->internalCsp != X265_CSP_I400)
  
          {
  
              primitives.extendRowBorder(reconPic->getCbAddr(m_rowAddr), strideC, reconPic->m_picWidth >> hChromaShift, realH >> vChromaShift, reconPic->m_chromaMarginX);
  
              primitives.extendRowBorder(reconPic->getCrAddr(m_rowAddr), strideC, reconPic->m_picWidth >> hChromaShift, realH >> vChromaShift, reconPic->m_chromaMarginX);
  
          }
  
      }
  
  
  
      // Extra Left and Right border on first and last CU
  
      if ((col == 0) | (col == m_frameFilter->m_numCols - 1))
  
      {
  
          copySizeY += lumaMarginX;
  
          copySizeC += chromaMarginX;
  
      }
  
  
  
      // First column need extension left padding area and first CU
  
      if (col == 0)
  
      {
  
          pixY -= lumaMarginX;
  
          pixU -= chromaMarginX;
  
          pixV -= chromaMarginX;
  
      }

• Revision 9f5fd31d7f : Expand UMV border to 96 pixels Ensures that the full 64 pixel border is availab

  29 avril 2013, par John Koleszar

  Changed Paths :
   Modify /vpx_scale/yv12config.h

  
  
  Expand UMV border to 96 pixels

  Ensures that the full 64 pixel border is available for prediction (need a
  minimum of
  64+INTERP_EXTEND on all sides, and 32+INTERP_EXTEND on UV). Value also must be a
  multiple of 32 to keep UV stride alignment. The smaller border was causing the
  prediction
  to read outside the frame, which can cause a mismatch.

  TODO : Get rid of this explicit border and use edge emulation instead.

  Change-Id : I3f68453a088ec0ab4349d0f5cc02b573be06d7c4

• Android - Lightweight solution for image video watermarking

  1er décembre 2015, par mtwain

  How to add image on video not using ffmpeg but using some another approach ? What more lightweight solutions exists for simple putting image on video ?

  I know few apps with this functionality that have very small size. What approach do they use ?

  1. https://play.google.com/store/apps/details?id=com.ashimpd.watermark
  2. https://play.google.com/store/apps/details?id=jcom.watermark.video