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• Streaming video from C# server to wowza streaming engine

  12 mai 2017, par mesomagik

  I’m facing problem with restreaming .h264 video received from my device via tcp to wowza streaming engine. The problem is that I do not know how to forward byte array (byte[]). I have read that it is possible via rstp/rtmp/mpegts but I have not found any library to do this operation. I know that video I receive is ok because after saving frames to file I’m able to send it to wowza using ffmpeg. I have been also trying to use ffmpeg to listen on udp ip and port and on http ip and port but nothing happened.

  ---

  My question is :
  Is it possible to send bytes to ffmpeg without saving file on hard drive ?

• FFMPEG : rtsp stream to a udp stream

  22 juin 2017, par Traffens

  I am looking for advice on using ffmpeg to convert RTSP stream to udp stream. What would be the simplest general command to do so ? This is what I have right now :

  ffmpeg -i rtsp://192.168.1.247/play1.sdp -f mpegts -vcodec mpeg4 -acodec mp2 udp://127.0.0.1:1234

  The error I’m getting :

  UDP timeout, retrying TCP

  method PAUSE failed : 405 PAUSE

  rtsp ://192.... : operation not permitted

  Finishing stream 0:0 without any data written to it.

  I’m running ubuntu 14.04. Thank you !

• FFMPEG providing support for HEVC decoding

  28 novembre 2013, par sam

  FFMPEG v2.1 onwards is providing support for HEVC Decoding. I tried an elementary input bin stream as an input for it and yes i got a corresponding YUV file.

  Now my question is, since i'm just passing an elementary stream as an input, how is the decoder parsing it ?

  I have gone through the /libavformat/hevcdec.c which is supposed to be a demuxer for HEVC.
  I know hevc_probe() is the function in hevcdec.c where it detects if the file can be decoded by the HEVC decoder.

  The definition of hevc_probe() function is given below :

  static int hevc_probe(AVProbeData *p)
  
  {
  
      uint32_t code = -1;
  
      int vps = 0, sps = 0, pps = 0, irap = 0;
  
      int i;
  
  
  
      for (i = 0; i < p->buf_size - 1; i++) {
  
          code = (code << 8) + p->buf[i];
  
          if ((code & 0xffffff00) == 0x100) {
  
              uint8_t nal2 = p->buf[i + 1];
  
              int type = (code & 0x7E) >> 1;
  
  
  
              if (code & 0x81) // forbidden and reserved zero bits
  
                  return 0;
  
  
  
              if (nal2 & 0xf8) // reserved zero
  
                  return 0;
  
  
  
              switch (type) {
  
              case NAL_VPS:        vps++;  break;
  
              case NAL_SPS:        sps++;  break;
  
              case NAL_PPS:        pps++;  break;
  
              case NAL_BLA_N_LP:
  
              case NAL_BLA_W_LP:
  
              case NAL_BLA_W_RADL:
  
              case NAL_CRA_NUT:
  
              case NAL_IDR_N_LP:
  
              case NAL_IDR_W_RADL: irap++; break;
  
              }
  
          }
  
      }
  
  
  
      // printf("vps=%d, sps=%d, pps=%d, irap=%d\n", vps, sps, pps, irap);
  
  
  
      if (vps && sps && pps && irap)
  
          return AVPROBE_SCORE_EXTENSION + 1; // 1 more than .mpg
  
      return 0;
  
  }

  According to whatever i have read, only if this function returns a constant of type AVPROBE_SCORE_EXTENSION, the decoding will proceed. However it is returning AVPROBE_SCORE_EXTENSION+1 Why is it ?

  Also as seen above in the code, they are deciding some type variable from the input bit code obtained and performing increment in the constants like sps, pps, etc. Is the the normal operation that needs to be performed by a parser which can decode an elementary stream ?

  It would be really helpful to everyone if anyone is able to give a brief of a parser of a decoder that can decode an elementary stream.

  Please Help. Thanks in advance.