Recherche avancée

Sur d’autres sites (11102)

• Display FFMPEG decoded frame in a GLFW window

  17 juin 2020, par Infecto

  I am implementing the client program of a game where the server sends encoded frames of the game to the client (via UDP), while the client decodes them (via FFMPEG) and displays them in a GLFW window. 
My program has two threads :

  



  

  1. Thread 1 : renders the content of the uint8_t* variable dataToRender

  


  2. Thread 2 : keeps obtaining frames from the server, decodes them and updates dataToRender accordingly

  


  



  Thread 1 does the typical rendering of a GLFW window in a while-loop. I have already tried to display some dummy frame data (a completely red frame) and it worked :

  



  while (!glfwWindowShouldClose(window)) {
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    ...

    glBindTexture(GL_TEXTURE_2D, tex_handle);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, window_width, window_height, 0, GL_RGB, GL_UNSIGNED_BYTE, dataToRender);
    ...
    glfwSwapBuffers(window);
}


  



  Thread 2 is where I am having trouble. I am unable to properly store the decoded frame into my dataToRender variable. On top if it, the frame data is originally in YUV format and needs to be converted to RGB. I use FFMPEG's sws_scale for that, which also gives me a bad dst image pointers error output in the console. Here's the code snippet responsible for that part :

  



          size_t data_size = frameBuffer.size();  // frameBuffer is a std::vector where I accumulate the frame data chunks
        uint8_t* data = frameBuffer.data();  // convert the vector to a pointer
        picture->format = AV_PIX_FMT_RGB24;
        av_frame_get_buffer(picture, 1);
        while (data_size > 0) {
            int ret = av_parser_parse2(parser, c, &pkt->data, &pkt->size,
                data, data_size, AV_NOPTS_VALUE, AV_NOPTS_VALUE, 0);
            if (ret < 0) {
                fprintf(stderr, "Error while parsing\n");
                exit(1);
            }
            data += ret;
            data_size -= ret;

            if (pkt->size) {
                swsContext = sws_getContext(
                    c->width, c->height,
                    AV_PIX_FMT_YUV420P, c->width, c->height,
                    AV_PIX_FMT_RGB24, SWS_BILINEAR, NULL, NULL, NULL
                );
                uint8_t* rgb24[1] = { data };
                int rgb24_stride[1] = { 3 * c->width };
                sws_scale(swsContext, rgb24, rgb24_stride, 0, c->height, picture->data, picture->linesize);

                decode(c, picture, pkt, outname);
                // TODO: copy content of picture->data[0] to "dataToRender" maybe?
            }
        }


  



  I have already tried doing another sws_scale to copy the content to dataToRender and I cannot get rid of the bad dst image pointers error. Any advice or solution to the problem would be greatly appreciated as I have been stuck for days on this.

  


• Black screen when recording specific screen / window using ffmpeg [closed]

  16 mai, par Mark Brin

  Issue :
I'm trying to capture the specific window using ffmpeg & i've tried these below command for that :

  


  ffmpeg -f gdigrab -framerate 30 -i title="Window Title" -b:v 3M -pix_fmt yuv420p output_FILENAME.webm


  


  And also try changing output format to .mp4

  


  ffmpeg -f gdigrab -framerate 30 -i title="Window Title" -b:v 3M -pix_fmt yuv420p output_FILENAME.mp4


  


  but the output video just shows the black screen with cursor.

  


  What i've tried :

  


  


  • Tried online solutions like Recording Screen with FFmpeg, How to record a specific window using ffmpeg ?, Record specific window using ffmpeg, but none of them worked.

    


  


  • even tried some of the tweaks like removing flags like -pix_fmt yuv420p also tried -f d3d11grab but didn't work.

    


  


  • When i try desktop capture it works completely fine.

    


  


  • I'm using this command to confirm that i'm using correct window title

    


  


  


  Get-Process |
  Where-Object { $_.MainWindowTitle -ne "" } |
  Select-Object -Unique MainWindowTitle


  


  System I'm using :

  


  Windows 11

  


• How to play H.264 video in a win32 window ?

  4 avril 2012, par parvez

  I came across a H.264 video which i would like to play in my c++ application. Could anyone suggest what could be the easiest way of doing it ? Or What library can be used for the purpose.

  Thanks in advance..