c++ - 如何修复这些错误？

Question

我正在尝试编写 FFmpeg 客户端流，但出现了一些错误

Error C4996 'av_register_all': was declared deprecated
Error C4996 'av_free_packet': was declared deprecated
Error C4996 'AVStream::codec': was declared deprecated
Error C4996 'avcodec_decode_video2': was declared deprecated
Error C4996 'avcodec_copy_context': was declared deprecated

  int size = avpicture_get_size(AV_PIX_FMT_YUV420P, 
  ccontext>width,ccontext->height);
  uint8_t* picture_buf = (uint8_t*)(av_malloc(size));
  AVFrame* pic = avcodec_alloc_frame();
  AVFrame* picrgb = avcodec_alloc_frame();
  int size2 = avpicture_get_size(AV_PIX_FMT_RGB24, ccontext->width, 
  ccontext->height);
  uint8_t* picture_buf2 = (uint8_t*)(av_malloc(size2));
  avpicture_fill((AVPicture *)pic, picture_buf, AV_PIX_FMT_YUV420P, 
  ccontext->width, ccontext->height);
  avpicture_fill((AVPicture *)picrgb, picture_buf2,AV_PIX_FMT_RGB24, 
  ccontext->width, ccontext->height);

  while (av_read_frame(context, &packet) >= 0 && cnt < 1000)
 {//read 100 frames

    std::cout << "1 Frame: " << cnt << std::endl;
    if (packet.stream_index == video_stream_index) 
    {//packet is video
        std::cout << "2 Is Video" << std::endl;
        if (stream == NULL)
        {//create stream in file
            std::cout << "3 create stream" << std::endl;
            stream = avformat_new_stream(oc, context- 
            >streams[video_stream_index]->codec->codec);
            avcodec_copy_context(stream->codec, context- 
            >streams[video_stream_index]->codec);
            stream->sample_aspect_ratio = context- 
            >streams[video_stream_index]->codec->sample_aspect_ratio;
        }
        int check = 0;
        packet.stream_index = stream->id;
        std::cout << "4 decoding" << std::endl;
        int result = avcodec_decode_video2(ccontext, pic,          
        &check,&packet);
        std::cout << "Bytes decoded " << result << " check " << check << 
        std::endl;
        if (cnt > 100)//cnt < 0)
        {
            sws_scale(img_convert_ctx, pic->data, pic->linesize, 0, 
            ccontext->height, picrgb->data, picrgb->linesize);
            std::stringstream name;
            name << "test" << cnt << ".ppm";
            myfile.open(name.str());
            myfile << "P3 " << ccontext->width << " " << ccontext->height 
                  << " 255\n";
            for (int y = 0; y < ccontext->height; y++)
            {
                for (int x = 0; x < ccontext->width * 3; x++)
                    myfile << (int)(picrgb-> 
                data[0] + y * picrgb->linesize[0])[x] << " ";
            }
            myfile.close();
        }

Answer 1

首先，这些应该是警告，而不是错误。如果它们是错误，则说明编译器设置太严格了

av_register_all - 不再使用，删除这一行

av_free_packet -> av_packet_unref

AVStream::codec -> AVStream::codecpar

avcodec_decode_video2 -> 将其替换为 avcodec_send_packet、avcodec_receive_frame 机制

最后: avcodec_copy_context -> 来自文档:

The semantics of this function are ill-defined and it should not be used. If you need to transfer the stream parameters from one codec context to another, use an intermediate AVCodecParameters instance and the avcodec_parameters_from_context() / avcodec_parameters_to_context() functions.