Recherche avancée

Sur d’autres sites (8596)

• FFMPEG 2 Videos transcoded and side by side in 1 frame ?

  3 mars 2016, par dcoffey3296

  I have 2 videos : HEADSHOT.MOV and SCREEN.MOV. They are both large files and I am looking to both shrink (size, bitrate, etc) and place these two side by side in the same, very wide, video frame. The end result would be that when you play the output_video.mp4, you would have a very wide frame with both videos in sync and playing at the same rate.

  Here is the syntatically incorrect version of what I am trying to do :

  ffmpeg -i HEADSHOT.MOV -t 00:02:00 -acodec libfaac -ab 64k -vcodec libx264 -r 30 -pass 1 -s 374x210 -vf "movie=SCREEN.MOV [small]; [in][small] -an -r 30 -pass 1 -s 374x210 overlay=10:10 -t 00:02:00 [out]" -threads 0 output_movie.mp4

  In the above example, I also tried to set a test movie duration for 2 minutes which raises another question, What is the best way to handle 2 movies of varying length (if they are close) ?

  The resources I have found helpful so far are :

  Multiple video sources combined into one and

  http://ffmpeg.org/ffmpeg.html#overlay-1

  Any help/advice is greatly appreciated. I am having trouble with the FFMPEG syntax ! Thank you !

• VLC libx264 streaming muxed as FLV

  24 mars 2012, par Jan Novák

  I have a question on streaming output of libx264. My scenario is that Iam capturing video from webcam, encoding with x264 and then streaming data to flash, muxed as FLV. For muxing, Im using output/flv_bitstream.h, included in libx264 budle. The only modification of muxer, that I made, is that instead of fwrite() im usig send() to transfer data via socket... Encoding library is working fine. If I save output (even muxed), vlc player is able to play it. But, when it goes to data transfer via socket, vlc and flash are not cooperating. The weird thig is, that if Im sending data to vlc player thru socket, it waits till transmission end and then plays video from buffer. But what I need is to play live stream.

  I also tryed to read flv file and send it to vlc of flash tag by tag and it is working fine.

  Any suggestions ?

• CVOpenGLESTextureCacheCreateTextureFromImage from uint8_t buffer

  6 novembre 2015, par resident_

  I’m developing an video player for iPhone. I’m using ffmpeg libraries to decode frames of video and I’m using opengl 2.0 to render the frames to the screen.

  But my render method is very slowly.

  A user told me :
  iOS 5 includes a new way to do this fast. The trick is to use AVFoundation and link a Core Video pixel buffer directly to an OpenGL texture.

  My problem now is that my video player send to render method a uint8_t* type that I use then with glTexSubImage2D.

  But if I want to use CVOpenGLESTextureCacheCreateTextureFromImage I need a CVImageBufferRef with the frame.

  The question is : How I can create CVImageBufferRef from uint8_t buffer ?

  This is my render method :

  - (void) render: (uint8_t*) buffer

  
  NSLog(@"render") ;

  [EAGLContext setCurrentContext:context];
  
  
  
  glBindFramebuffer(GL_FRAMEBUFFER, defaultFramebuffer);
  
  glViewport(0, 0, backingWidth, backingHeight);
  
  
  
  glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
  
  
  
  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  
  
  
  // OpenGL loads textures lazily so accessing the buffer is deferred until draw; notify
  
  // the movie player that we're done with the texture after glDrawArrays.         
  
  glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, mFrameW, mFrameH, GL_RGB,GL_UNSIGNED_SHORT_5_6_5, buffer);   
  
  
  
  glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
  
  
  
  [moviePlayerDelegate bufferDone];
  
  
  
  glBindRenderbuffer(GL_RENDERBUFFER, colorRenderbuffer);
  
  [context presentRenderbuffer:GL_RENDERBUFFER];

  Thanks,