[FFmpeg-user] Decoding slice based frames

[d.gordenin at ngslab.ru]

Nobody knows?
Where can I find the format of the slice-based frames? Is there an 
example of decoding them?
> Hi
>
> My decoder receives slice based frame, and it cannot decode them (the 
> result is a greased picture). How should I decode them and which are 
> differences from decoding a usual frame? My code of dedoding is 
> canonical:
>
>   if (size >= sizeof(kh264Prefix) && memcmp(data, kh264Prefix, 
> sizeof(kh264Prefix)) != 0)
>   {
>     if (size > prefix_buffer_.size() - sizeof(kh264Prefix))
>     {
>       logger_->Error("Too large data packet for decoding");
>       return false;
>     }
>
>     memcpy(prefix_buffer_.data() + sizeof(kh264Prefix), data, size);
>
>     data = prefix_buffer_.data();
>     size += sizeof(kh264Prefix);
>   }
>
>   AVPacket avpkt;
>   av_init_packet(&avpkt);
>   avpkt.pts = 0;
>   avpkt.dts = 0;
>   avpkt.data = data;
>   avpkt.size = size;
>
>   int gotFrame = false;
>
>   while (avpkt.size > 0)
>   {
>     // We must use positive result to move through the data buffer
>     auto len = avcodec_decode_video2(av_context_, av_frame_, 
> &gotFrame, &avpkt);
>     if (len < 0)
>     {
>       // In case of an error/warning FFmpeg will call
>       // decoder::LogCallback(...) to inform about the issue
>       break;
>     }
>
>     avpkt.data += len;
>     avpkt.size -= len;
>   }
>
>   av_free_packet(&avpkt);
>
> I tried the AV_CODEC_CAP_SLICE_THREADS flag, not sure is it for 
> decoding or not.
>
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