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• android ffmpeg opengl es render movie

  18 janvier 2013, par broschb

  I am trying to render video via the NDK, to add some features that just aren't supported in the sdk. I am using FFmpeg to decode the video and can compile that via the ndk, and used this as a starting point. I have modified that example and instead of using glDrawTexiOES to draw the texture I have setup some vertices and am rendering the texture on top of that (opengl es way of rendering quad).

  Below is what I am doing to render, but creating the glTexImage2D is slow. I want to know if there is any way to speed this up, or give the appearance of speeding this up, such as trying to setup some textures in the background and render pre-setup textures. Or if there is any other way to more quickly draw the video frames to screen in android ? Currently I can only get about 12fps.

  glClear(GL_COLOR_BUFFER_BIT);
  
  glEnableClientState(GL_VERTEX_ARRAY);
  
  glEnableClientState(GL_TEXTURE_COORD_ARRAY);
  
  glBindTexture(GL_TEXTURE_2D, textureConverted);
  
  
  
  //this is slow
  
  glTexImage2D(GL_TEXTURE_2D, /* target */
  
  0, /* level */
  
  GL_RGBA, /* internal format */
  
  textureWidth, /* width */
  
  textureHeight, /* height */
  
  0, /* border */
  
  GL_RGBA, /* format */
  
  GL_UNSIGNED_BYTE,/* type */
  
  pFrameConverted->data[0]);
  
  
  
  glEnableClientState(GL_TEXTURE_COORD_ARRAY);
  
  glTexCoordPointer(2, GL_FLOAT, 0, texCoords);
  
  glVertexPointer(3, GL_FLOAT, 0, vertices);
  
  glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_BYTE, indices);
  
  glDisableClientState(GL_VERTEX_ARRAY);
  
  glDisableClientState(GL_TEXTURE_COORD_ARRAY);

  EDIT
  I changed my code to initialize a gltextImage2D only once, and modify it with glSubTexImage2D, it didn't make much of an improvement to the framerate.

  I then modified the code to modify a native Bitmap object on the NDK. With this approach I have a background thread that runs that process the next frames and populates the bitmap object on the native side. I think this has potential, but I need to get the speed increased of converting the AVFrame object from FFmpeg into a native bitmap. Below is currently what I am using to convert, a brute force approach. Is there any way to increase the speed of this or optimize this conversion ?

  static void fill_bitmap(AndroidBitmapInfo*  info, void *pixels, AVFrame *pFrame)
  
  {
  
  uint8_t *frameLine;
  
  
  
  int  yy;
  
  for (yy = 0; yy < info->height; yy++) {
  
      uint8_t*  line = (uint8_t*)pixels;
  
      frameLine = (uint8_t *)pFrame->data[0] + (yy * pFrame->linesize[0]);
  
  
  
      int xx;
  
      for (xx = 0; xx < info->width; xx++) {
  
          int out_offset = xx * 4;
  
          int in_offset = xx * 3;
  
  
  
          line[out_offset] = frameLine[in_offset];
  
          line[out_offset+1] = frameLine[in_offset+1];
  
          line[out_offset+2] = frameLine[in_offset+2];
  
          line[out_offset+3] = 0;
  
      }
  
      pixels = (char*)pixels + info->stride;
  
  }
  
  }

• Download Partial Video via HTTP (for Remote Thumbnailing)

  13 février 2012, par HuntedC

  I have videos hosted on Amazon S3. I encode them with Zencoder and store a thumbnail for the video then using Zencoder. However, I need a way to generate thumbnails at certain points in the video (i.e. 00:00:03, 00:10:32, 01:40:18) and store them either on S3 or my server.

  ffmpeg allows remote thumbnailing, however it takes a very long time (sometimes several minutes) to get a thumbnail from the middle of a file—I believe this is because it downloads the entire file up to that point to get the thumbnail.

  My plan is to somehow download the header of the video file via HTTP byte-range request, guesstimate the byte range where I should be looking for the thumbnail, download about a second of video from that part of the file via HTTP byte-range request, then save the header and tiny video locally. I pull the thumbnail from that using ffmpeg and delete the temporary video.

  I have no idea on how exactly this would work (I believe the H.264 MP4 files I'm working with have a dynamic length header, for another issue). Any suggestions or better ideas ?

  Edit : To clarify, Zencoder thumbnailing is great, but they only allow thumbnail creation in combination with transcoding. I don't want to transcode my video every time I create a new thumbnail, so I need to do this on my own without Zencoder.

• lavfi/movie : reindent after the previous patch

  7 juillet 2012, par Steven Robertson

  lavfi/movie : reindent after the previous patch