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• How to stream raw H264 ? [closed]

  31 mars 2023, par Alexander Lazarenko

  I don't know anything about streaming, so don't judge me harshly.

  


  The program receives bytes from TCP stream, processes them and adds to byte array. This array contains raw H264 frames.

  


  If they are saved and then broadcasted, the broadcast will be interrupted. Is there something I can do to avoid restarting broadcast ?

  


  Thanks in advance

  


• How to gain volumes of specific bands of audio files using ffmpeg ?

  10 mai 2019, par Ko Ohhashi

  I want increase or decrease volume of specific frequency bands with ffmpeg.

  I think bandreject and bandpass filter can do similar thing.
  But is there any way to reject 80% of energy of specific bands ?

  Thanks in advance ?

• using FFmpeg, how to decode H264 packets

  28 mars 2017, par Jun

  I’m new to FFmpeg struggling to decode H264 packets which can be obtained as an array of uint8_t.

  After many of investigations, I think it should be able to just put the array into an AVPacket like the below

  AVPacket *avpkt = (AVPacket *)malloc(sizeof(AVPacket) * 1);
  
  av_init_packet(avpkt);  
  
  avpkt->data = ct;   // ct is the array
  
  avpkt->length =....

  and decode by avcodec_decode_video2(). A part of the code is like

  ...
  
  codec = avcodec_find_decoder(CODEC_ID_H264);
  
  gVideoCodecCtx = avcodec_alloc_context();
  
  gFrame = avcodec_alloc_frame();
  
  avcodec_decode_video2(gVideoCodecCtx, gFrame, &frameFinished, packet);
  
  ...

  I guess I set all required properties properly but this function is returning only -1 :(

  I just found the -1 is coming from

  ret = avctx->codec->decode(avctx, picture, got_picture_ptr, avpkt) ;

  in the avcodec_decode_video2() ;

  Actually, what I’m wondering is if I can decode H264 packets (without RTP header) by avcodec_decode_video2().

  Thanks for the help in advance.

  ---

  /////////// added

  OK, I’m still trying to find a solution. What I’m doing now is the below

  ** the H264 stream in this RTP stream is encoded by FU-A

  1. receive a RTP packet

  2. look if the second byte of the RTP header is > 0 which means it’s the first packet (and possibly will be followed)

  3. see if the next RTP packet has > 0 at its second byte also, then it means the previous frame was a complete NAL or if this is < 0, the packet should be appended to the previous packet.

  4. remove all RTP header of the packets so it has only like FU indicator | FU header | NAL

  5. try play it with avcodec_decode_video2()

  but it’s only returning -1..... am I supposed to remove FU indicator and header too ??

  any suggestion will be very appreciated

  thanks in advance.