Hi,
I am using x264 for live video stream encoding and then it is transmitted over rtp. In my server application I get feedback from my rtp client about which particular frame has been received by the decoder without any error. So for my next frame encoding I want to reference from that frame which has been received by decoder.
To do this I am dropping frame from my encoder's DPB.

I am trying this code for frame dropping in the reference list.

x264_frame_t ** frames = h->frames.reference
while(*frames)
{
      if( *frames->i_poc  != received_poc)
              x264_frame_push_unused(h, x264_frame_shift(frames));
      else
             frames++
}

I have inserted this code in x264_encoder_encode function just before
 if( x264_reference_update( h ) )
        return -1;
I is it the right code and right place? Do I need to do anything else for frame dropping?

I have checked h->frames.reference is a 16 size array, Does that mean x264 always keeps 16 frames in its DPB?

If I find that received_poc is 10 frames earlier ( aasume poc=n) than the current frame to be encoded and if it is available in my DPB then after encoding at my client's decoder reference buffer will that nth frame be still available for referencing?

Thanks
Arindam

Thank you for your response. I will defenitely try out periodic intra refresh.

I am streaming 480P and 720P video over wireless and using vlc media player at client end for playback. I have configured x264 keyint max 15, keyint min 5, and 8 slices per frame.
In the normal condition I am getting 5% packet loss and I am using rate adaptation and
retransmission to recover from that.
But in case of interference the loss is going as high as 50% and I am seeing stall, artifact in vlc media player and some times vlc player just gives up.
After checking wireshark packet capture I found consecutive 5 to 10 frame loss in case of interference. This is the reason why I was thinking about dynamic reference picture selection based on client's feedback. Will this technique help in this kind of scenario?

Can you suggest me if there is any other techniques, special kind of encoder profiling which can be quickly implemented on x264/ patch available  in order to reduce stalls, jerks, artifacts at vlc player end.

Thanks
Arindam
 

Hello,