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• ffplay too slow decoding h264 stream over RTP

  16 mars 2018, par Alejandro Aristizábal

  I need some help getting ffplay to receive and decode a Real Time stream encoded in h264.

  I’m trying to make a point-to-point stream between computer A receiving video frames from a Kinect and computer B running ffplay to show the livestream.

  These are the commands I’m running on both computers.

  Computer A (RPI 3)

  ffmpeg -f rawvideo -vcodec rawvideo -pix_fmt rgb24 -s 640x480 -i - -threads 4 -preset ultrafast -codec:v libx2 64 -an -f rtp rtp://192.168.0.100:2000

  This is what ffmpeg outputs :

  fps= 14 q=12.0 size=856kB time=00:00:05.56 bitrate=1261.4kbits/s speed=0.54x

  The out stream runs in between 10-20 frames. It’s not good, but I can work with that.

  Computer B

  ffplay -protocol_whitelist "file,udp,rtp" -probesize 32 -sync ext -i streaming.sdp

  streaming.sdp

  v=0
  
  0=- 0 0 IN IP4 127.0.0.1
  
  s=No Name
  
  c=IN IP4 192.168.0.100
  
  t=0 0
  
  a=tool:libavformat 57.56.100
  
  m=video 2000 RTP/AVP 96
  
  a=rtpmap:96 H264/90000
  
  a=fmtp:96 packetization-mode=1

  I’m getting the stream, but at about 0.0001fps which is crearly bad. My guess is I’m missing something on the ffplay command, since ffmpeg shows a more stable and fast stream, but I can’t seem to find what I’m missing.

  Thanks in advance

• Anomalie #3877 : Créer un nouvelle traduction perd la redirection (et les logos)

  16 décembre 2016, par b b

  Le bon projet...

  Après vérification, sur une 2.1.29 la traduction hérite bien de la redirection, mais pas du logo (donc pour ce point c’est une évolution).

• FFMPEG : Mapping YUV data to output buffer of decode function

  22 décembre 2013, par Zax

  I am modifying a video decoder code from FFMPEG. The decoded code is of format YUV420. I'm having 3 pointers, each pointing to Y, U and V data i.e :

  yPtr-> is a pointer pointing to the Luma
  
  uPtr-> is a pointer pointing to the Chroma Cb
  
  vPtr-> is a pointer pointing to the Chroma Cr

  However, the output pointer to which I need to map my YUV data is of type void. And the output pointer is just one.

  i.e : void *data is the output pointer for which I need to point my yPtr, uPtr and vPtr. How should I do this ?

  One approach I have tried is, created a new buffer whose size is equal to the sum of Y, U and V data, and copy the contents of yPtr, uPtr and vPtr to the newly allocated buffer, and the pointer to this buffer I'm allocating to *data output pointer.

  However this approach is not preferred because memcpy needs to be performed and other performance drawbacks.

  Can anyone please suggest an alternative for this issue. This may be not related directly to FFMPEG, but since I'm modifying FFMPEG's libavcodec's decoder code, I'm tagging it in FFMPEG.

  Edit : What I'm trying to do :

  Actually my understanding is if I make this pointer point to void *data pointer of any decode function of any decoder and setting *got_frame_ptr to 1, the framework will take care of dumping this data into the yuv file. is my understanding right ?

  The function prototype of my custom video decoder or any video decoder in ffmpeg is as shown below :

  static int myCustomDec_decode_frame(AVCodecContext *avctx,
  
              void *data, int *data_size,
  
              uint8_t *buf, int buf_size) {

  I'm referring to this post FFMPEG : Explain parameters of any codecs function pointers and assuming that I need to point *data to my YUV data pointer, and the dumping stuff will be taken care by ffmpeg. Please provide suggestions regrading the same.