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• Streaming client over TCP and RTSP through Wi-Fi or LAN in Android

  6 janvier 2015, par Gowtham

  I am struggling to develop streaming client for DVR camera’s, I tried with VLC Media player through RTSP protocol I got the solution (used Wi-Fi standard model like, Netgear etc.,), but the same code is not supporting for other Wi-Fi Modem’s, now am working with FFMPEG framework to implement the streaming client in android using JNI API. Not getting any proper idea to implement JNI api

  Network Camera working with IP Cam Viewer App

  code below,

  /*****************************************************/
  
  /* functional call */
  
  /*****************************************************/
  
  
  
  jboolean Java_FFmpeg_allocateBuffer( JNIEnv* env, jobject thiz )
  
  {
  
  
  
      // Allocate an AVFrame structure
  
      pFrameRGB=avcodec_alloc_frame();
  
      if(pFrameRGB==NULL)
  
          return 0;
  
  sprintf(debugMsg, "%d %d", screenWidth, screenHeight);
  
  INFO(debugMsg);
  
      // Determine required buffer size and allocate buffer
  
      numBytes=avpicture_get_size(dstFmt, screenWidth, screenHeight);
  
  /*
  
      numBytes=avpicture_get_size(dstFmt, pCodecCtx->width,
  
                    pCodecCtx->height);
  
  */
  
      buffer=(uint8_t *)av_malloc(numBytes * sizeof(uint8_t));
  
  
  
      // Assign appropriate parts of buffer to image planes in pFrameRGB
  
      // Note that pFrameRGB is an AVFrame, but AVFrame is a superset
  
      // of AVPicture
  
      avpicture_fill((AVPicture *)pFrameRGB, buffer, dstFmt, screenWidth, screenHeight);
  
  
  
      return 1;
  
  }
  
  
  
  
  
  /* for each decoded frame */
  
  jbyteArray Java_FFmpeg_getNextDecodedFrame( JNIEnv* env, jobject thiz )
  
  {
  
  
  
  
  
  av_free_packet(&packet);
  
  
  
  while(av_read_frame(pFormatCtx, &packet)>=0) {
  
  
  
      if(packet.stream_index==videoStream) {
  
  
  
          avcodec_decode_video2(pCodecCtx, pFrame, &frameFinished, &packet);
  
  
  
          if(frameFinished) {     
  
  
  
          img_convert_ctx = sws_getContext(pCodecCtx->width, pCodecCtx->height, pCodecCtx->pix_fmt, screenWidth, screenHeight, dstFmt, SWS_BICUBIC, NULL, NULL, NULL);
  
  
  
  /*
  
  img_convert_ctx = sws_getContext(pCodecCtx->width, pCodecCtx->height, pCodecCtx->pix_fmt, pCodecCtx->width, pCodecCtx->height, dstFmt, SWS_BICUBIC, NULL, NULL, NULL);
  
  */
  
  
  
          sws_scale(img_convert_ctx, (const uint8_t* const*)pFrame->data, pFrame->linesize,
  
       0, pCodecCtx->height, pFrameRGB->data, pFrameRGB->linesize);
  
  
  
  ++frameCount;
  
  
  
          /* uint8_t == unsigned 8 bits == jboolean */
  
          jbyteArray nativePixels = (*env)->NewByteArray(env, numBytes);
  
          (*env)->SetByteArrayRegion(env, nativePixels, 0, numBytes, buffer);
  
          return nativePixels;
  
          }
  
  
  
      }
  
  
  
      av_free_packet(&packet);
  
  }
  
  
  
  return NULL;
  
  }
  
  
  
  /*****************************************************/
  
  /* / functional call */
  
  /*****************************************************/
  
  
  
  
  
  jstring
  
  Java_FFmpeg_play( JNIEnv* env, jobject thiz, jstring jfilePath )
  
  {
  
      INFO("--- Play");
  
  char* filePath = (char *)(*env)->GetStringUTFChars(env, jfilePath, NULL);
  
  RE(filePath);
  
  
  
  /*****************************************************/
  
  
  
    AVFormatContext *pFormatCtx;
  
    int             i, videoStream;
  
    AVCodecContext  *pCodecCtx;
  
    AVCodec         *pCodec;
  
    AVFrame         *pFrame; 
  
    AVPacket        packet;
  
    int             frameFinished;
  
    float           aspect_ratio;
  
    struct SwsContext *img_convert_ctx;
  
  
  
  INFO(filePath);
  
  
  
  /* FFmpeg */
  
  
  
    av_register_all();
  
  
  
    if(av_open_input_file(&pFormatCtx, filePath, NULL, 0, NULL)!=0)
  
      RE("failed av_open_input_file ");
  
  
  
    if(av_find_stream_info(pFormatCtx)<0)
  
          RE("failed av_find_stream_info");
  
  
  
    videoStream=-1;
  
    for(i=0; inb_streams; i++)
  
      if(pFormatCtx->streams[i]->codec->codec_type==AVMEDIA_TYPE_VIDEO) {
  
        videoStream=i;
  
        break;
  
      }
  
    if(videoStream==-1)
  
          RE("failed videostream == -1");
  
  
  
    pCodecCtx=pFormatCtx->streams[videoStream]->codec;
  
  
  
    pCodec=avcodec_find_decoder(pCodecCtx->codec_id);
  
    if(pCodec==NULL) {
  
      RE("Unsupported codec!");
  
    }
  
  
  
    if(avcodec_open(pCodecCtx, pCodec)<0)
  
      RE("failed codec_open");
  
  
  
    pFrame=avcodec_alloc_frame();
  
  
  
  /* /FFmpeg */
  
  
  
  INFO("codec name:");
  
  INFO(pCodec->name);
  
  INFO("Getting into stream decode:");
  
  
  
  /* video stream */
  
  
  
    i=0;
  
    while(av_read_frame(pFormatCtx, &packet)>=0) {
  
  
  
      if(packet.stream_index==videoStream) {
  
        avcodec_decode_video2(pCodecCtx, pFrame, &frameFinished, &packet);
  
        if(frameFinished) {
  
  ++i;
  
  INFO("frame finished");
  
  
  
      AVPicture pict;
  
  /*
  
      img_convert_ctx = sws_getContext(pCodecCtx->width, pCodecCtx->height,
  
   pCodecCtx->pix_fmt, pCodecCtx->width, pCodecCtx->height,
  
   PIX_FMT_YUV420P, SWS_BICUBIC, NULL, NULL, NULL);
  
  
  
      sws_scale(img_convert_ctx, (const uint8_t* const*)pFrame->data, pFrame->linesize,
  
   0, pCodecCtx->height, pict.data, pict.linesize);
  
  */
  
        }
  
      }
  
      av_free_packet(&packet);
  
    }
  
  
  
  /* /video stream */
  
  
  
    av_free(pFrame);
  
  
  
    avcodec_close(pCodecCtx);
  
  
  
    av_close_input_file(pFormatCtx);
  
  
  
    RE("end of main");
  
  }

  I can’t able to get the frames from Network camera

  And give some idea to implement the live stream client for DVR camera in Android

• Implications of `DPB size > level limit` ?

  4 juillet 2022, par jippyjoe4

  I'm using ffmpeg and the libx264rgb codec to encode 5760x3240 PNG sequences into lossless .mp4 files. When I do this, I get the warning in yellow text :

  


  DPB size (16 frames, 1169280 mbs) > level limit (9 frames, 696320 mbs)

  


  I'm not completely sure what it means. Although it is slow, the encoder does finish encoding the files into a .mp4 file, from which I can extract the frames again losslessly.

  


  What does this warning mean, and what is the implication ?

  


• When player client starts to play a dash media

  7 juillet 2022, par CoXier

  I'm working on Android Player for playing dash media.

  


  In order to enable video starting fast, I preload a part of dash media, now the size of preload is 600kb.

  


  As you see, 600kb is a magic number. In my opinion, different size should be preloaded for different dash file.

  


  All start position of dash media is 0.

  


  I want to know : How to know the size of dash media which can support player starts to play ?

  


  Thanks for your help.