Recherche avancée

Sur d’autres sites (4692)

• Does FFMPEG utilize CUDA or any other hardware acceleration yet ?

  17 août 2017, par Jason

  Simple question, but I am having trouble finding the answer.

  We are deciding on a transcoding engine (preferrably open source) and it looks to me that FFMPEG does not utilize hardware acceleration, but I am not sure.

  I believe ffmpeg uses libavcodec, the same library used in countless other products, such as Handbrake. I can’t believe they don’t support hardware acceleration, therefore, my question.

• X264 Encoder API

  16 avril 2014, par user1884325

  I’m studying the X264 API for encoding images.

  So far I’ve built the X264 library and the following code snippet shows how far I am :

    int frame_size;
  
    x264_t* encoder;
  
    x264_picture_t pic_in, pic_out;
  
    x264_param_t x264Param;
  
    int fps = 20;
  
    int width = 1280;
  
    int height = 720;
  
    x264_nal_t* nals;
  
    int i_nals;
  
  
  
    x264_param_default_preset(&x264Param, "veryfast", "zerolatency");
  
    x264Param.i_threads = 1;
  
    x264Param.i_width = 1280;
  
    x264Param.i_height = 720;
  
    x264Param.i_fps_num = fps;
  
    x264Param.i_fps_den = 1;
  
    x264Param.i_keyint_max = fps;
  
    x264Param.b_intra_refresh = 1;
  
    x264Param.rc.i_rc_method = X264_RC_CRF;
  
    x264Param.rc.f_rf_constant = 25;
  
    x264Param.rc.f_rf_constant_max = 35;
  
    x264Param.b_repeat_headers = 1;
  
    x264Param.b_annexb = 1;
  
    x264_param_apply_profile(&x264Param, "baseline");
  
  
  
    encoder = x264_encoder_open(&x264Param);
  
  
  
    x264_picture_alloc(&pic_in, X264_CSP_BGR, width, height);
  
  
  
    /* How to fill in bitmap data? */
  
  
  
    frame_size = x264_encoder_encode(encoder, &nals, &i_nals, &pic_in, &pic_out);
  
    if (frame_size >= 0)
  
    {
  
        printf("OK\n");
  
    }

  So I’m trying to encode a 24bit BGR bitmap image. However, the x264 header file doesn’t show any API function for writing the bitmap image to the encoder. How is this done ?

  EDIT

  This code snippet seems to work. I would appreciate a review and some comments. Thanks.

    int frame_size;
  
    int accum_frame_size;
  
    x264_t* encoder;
  
    x264_picture_t pic_in, pic_out;
  
    x264_param_t x264Param;
  
    int fps = 20;
  
    int width = 1280;
  
    int height = 720;
  
    x264_nal_t* nals;
  
    int i_nals;
  
    int64_t frameCount = 0;
  
    int k;
  
  
  
    for (k = 0; k < (1280*3*720); k++)
  
    {
  
       bgr[k] = rand();
  
    }
  
  
  
    x264_param_default_preset(&x264Param, "veryfast", "zerolatency");
  
    x264Param.i_threads = 1;
  
    x264Param.i_width = 1280;
  
    x264Param.i_height = 720;
  
    x264Param.i_fps_num = fps;
  
    x264Param.i_fps_den = 1;
  
    x264Param.i_keyint_max = fps;
  
    x264Param.b_intra_refresh = 1;
  
    x264Param.rc.i_rc_method = X264_RC_CRF;
  
    x264Param.i_csp = X264_CSP_BGR;
  
    x264Param.rc.f_rf_constant = 25;
  
    x264Param.rc.f_rf_constant_max = 35;
  
    x264Param.b_repeat_headers = 1;
  
    x264Param.b_annexb = 1;
  
    x264_param_apply_profile(&x264Param, "baseline");
  
  
  
    encoder = x264_encoder_open(&x264Param);
  
  
  
    x264_picture_alloc(&pic_in, X264_CSP_BGR, width, height);
  
  
  
    /* Load 24-bit BGR bitmap */
  
    pic_in.img.i_csp = X264_CSP_BGR;
  
    pic_in.img.i_plane = 1;
  
    pic_in.img.i_stride[0] = 3 * 1280;
  
    pic_in.img.plane[0] = bgr;
  
    pic_in.i_pts = frameCount;
  
    pic_in.i_type = X264_TYPE_AUTO;
  
    pic_out.i_pts = frameCount;
  
  
  
    /* Returns a frame size of 912 for first frame in this case */
  
    frame_size = x264_encoder_encode(encoder, &nals, &i_nals, &pic_in, &pic_out);
  
  
  
    printf("Decoder returned frame size = %d \n", frame_size);
  
    printf("Decoder returned %d NAL units \n", i_nals);
  
    if (frame_size >= 0)
  
    {
  
       int i;
  
       int j;
  
  
  
  
  
       accum_frame_size = 0;
  
       for (i = 0; i < i_nals; i++)
  
       {
  
          printf("******************* NAL %d (%d bytes) *******************\n", i, nals[i].i_payload);
  
          for (j = 0; j < nals[i].i_payload; j++)
  
          {
  
             if (j == 0) printf("First 10 bytes: ");
  
             if (j < 10) printf("%02X |", nals[i].p_payload[j]);
  
             accum_frame_size++;
  
          }
  
          printf("\n");
  
  
  
       }
  
    }
  
  
  
    printf("Verified frame size = %d \n", accum_frame_size);

  EDIT #2
  The encoder outputs this :

       x264 [error]: baseline profile doesn't support 4:4:4
  
       x264 [info]: using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX
  
       x264 [info]: profile High 4:4:4 Predictive, level 3.1, 4:4:4 8-bit
  
       Decoder returned frame size = 1467194
  
       Decoder returned 4 NAL units
  
       ******************* NAL 0 (31 bytes) *******************
  
       First 10 bytes: 00 |00 |00 |01 |67 |F4 |00 |1F |91 |89 |
  
       ******************* NAL 1 (8 bytes) *******************
  
       First 10 bytes: 00 |00 |00 |01 |68 |EF |1F |2C |
  
       ******************* NAL 2 (595 bytes) *******************
  
       First 10 bytes: 00 |00 |01 |06 |05 |FF |FF |4C |DC |45 |
  
       ******************* NAL 3 (1466560 bytes) *******************
  
       First 10 bytes: 00 |00 |01 |65 |88 |82 |0A |FF |F5 |B0 |
  
       Verified frame size = 1467194

  Isn’t each NAL unit supposed to start with 0x00 0x00 0x00 0x01 ?

  szatmary : I appreciate your valuable feedback. So you’re saying that each NAL unit does not necessarily start with 0,0,0,1. However, I’m a bit unclear on your answer. Are you implying that with a certain configuration the NAL units will start with 0,0,0,1 ? If so, which configuration is that ? I need to make sure that each NAL unit I transmit out on the network to a remote receiver starts with 0,0,0,1. Prior to exploring the x264 library I was using the x264 exe and piped BMP data in and encoded data out from the x264 process. I then parsed the encoder output and looked for NAL units by looking for 0,0,0,1. How do I accomplish the same with the x264 library ?

  Regarding libswscale :

  I downloaded the ffmpeg source and ran configure and make in MINGW. After the process had completed I couldn’t find anything but a number of .exe files. How do I build actual static libraries (.lib) which I can use in a Visual Studio project ?

• Howcan I get the colormatrix of colorchannelmixer of ffmpeg

  25 janvier 2019, par gn cavalry

  I want to add some color filter to video, just like image below :
  

  colorchannelmixer need a 4x4 ColorMatrix, Where can I find this ColorMatrix, or which tool can help me to figure out some ColorMatrix.

  (I found a tool called ColorMatrixViewer.exe, but it’s a 5x5 ColorMatrix, I just extract a 4x4 maxtrix from it and apply the 4x4 maxtix to colorchannelmixer, theirs result are different)

  Thanks for your answer.