Recherche avancée

Sur d’autres sites (9231)

• Révision 17738 : parametre retour facultatif dans ask_php_auth (utilisé dans l’extension forum)

  20 avril 2011, par cedric -

• Resize camera preview frame using Ffmpeg

  20 avril 2015, par Vipul Purohit

  Scenario :
  I’m working on a live video stream application, in that I need to stream video at resolution around 380x240. I’m sending the camera preview byte[] to streamer from onPreviewFrame event of Camera.PreviewCallback.
  But I need to show camera preview in 720p/1080p but its not possible due to low resolution video streaming.

  Problem
  The solution I’m working is to reduce the video frame size from HD to a low resolution and then send it to streamer and for that I’m using FFMPEG’s sws_scale.

  I’ve successfully compiled the FFMPEG and can access and execute the JNI methods. But I’m completely new to android NDK development and not very familiar with the C/C++ language so I need help in writing JNI method to scale down the video frame.

  Here is what I’m having in my JNI method :

  JNIEXPORT jbyteArray JNICALL Java_com_example_ffmpegtest_MainActivity_resizeFrame(
  
      JNIEnv * env, jobject pObj, jbyteArray *input, jbyteArray * output,
  
      int width, int height) {
  
  struct SwsContext *resize;
  
  
  
  resize = sws_getContext(width, height, PIX_FMT_YUV420P, width, height,
  
          AV_PIX_FMT_YUV420P, SWS_BICUBIC, NULL, NULL, NULL);
  
  LOGI("---RESIZE");
  
  AVFrame* picture = avcodec_alloc_frame(); // this is your original frame
  
  AVFrame* outpic = avcodec_alloc_frame();
  
  
  
  int num_bytes = avpicture_get_size(PIX_FMT_YUV420P, width, height);
  
  jbyteArray data = (*env)->NewByteArray(env, num_bytes);
  
  uint8_t* frame2_buffer = (uint8_t *) av_malloc(num_bytes * sizeof(uint8_t));
  
  LOGI("---NUMBYTES ED");
  
  
  
  avpicture_fill((AVPicture*) picture, input, PIX_FMT_YUV420P, width, width);
  
  
  
  avpicture_fill((AVPicture*) outpic, frame2_buffer, PIX_FMT_YUV420P, 600,
  
          600);
  
  
  
  sws_scale(resize, picture->data, picture->linesize, 600, 600, outpic->data,
  
          outpic->linesize);
  
  
  
  sws_freeContext(resize);
  
  
  
  (*env)->SetByteArrayRegion(env, data, 0, num_bytes, outpic);
  
  LOGI("---SCALE %d", picture->data);
  
  LOGI("---SCALE_OUT %d", outpic->data);
  
  return output;

  }

  Here is the fuction for JNI method :

  private static native byte[] resizeFrame(byte[] input, byte[] output, int width, int height);

  and the Camera.PreviewCallback

  @Override
  
  public void onPreviewFrame(byte[] data, Camera camera) {
  
      byte[] data2 = null;
  
  
  
      data2 = resizeFrame(data, data2, mPreview.mPreviewSize.width,
  
              mPreview.mPreviewSize.height);
  
  
  
      // Code to send camera frame to streamer
  
  }

  I’m always getting data2 null.
  I know its a bad coding practices but I’m just keep changing the code to make it work but failed.

• Audio in ffmpeg

  1er octobre 2020, par Konduri Sai Aditya

  I need to add audio as an input to below command, How can I achieve it

  


  ffmpeg -i test.png -i test.mp4 -y -filter_complex "[1:v]scale=1422:800[scale1],[scale1]rotate=0:c=black@0:ow=rotw(0):oh=roth(0)[rotate0],[0:v][rotate0]overlay=258.04:107.71[mediaoverlayout0],color=black@0:451x137[c1],[c1]setsar=1,drawtext=fontfile='/Windows/fonts/Peddana-Regular.ttf':text='ADITYA':fontsize=121.19999999999999:fontcolor=#1e8bc3:line_spacing=16.91,rotate=0:ow=rotw(0):oh=roth(0):c=black@0[rottext1],[mediaoverlayout0][rottext1]overlay=x=544.63:y=263.076:shortest=1" -pix_fmt yuv420p op.mp4