解码(二):音视频解码上下文创建配置和打开avcodec_open2打开演示

如下代码：

/
	///视频解码器打开	
	///找到视频解码器
	AVCodec *vcodec = avcodec_find_decoder(ic->streams[videoStream]->codecpar->codec_id);

	if (!vcodec)
	{
		cout << "can't find the codec id" << ic->streams[videoStream]->codecpar->codec_id << endl;
		getchar();
		return -1;
	}
	cout << "find the video AVCodec" << ic->streams[videoStream]->codecpar->codec_id << endl;

	///创建解码器上下文
	AVCodecContext *vc = avcodec_alloc_context3(vcodec);
	///配置解码器上席文参数
	avcodec_parameters_to_context(vc, ic->streams[videoStream]->codecpar);
	//8线程解码器
	vc->thread_count = 8; 
	///打开解码器上下文
	re = avcodec_open2(vc, 0,0);
	if (re != 0)
	{
		char buffer[1024];
		av_strerror(re, buffer, sizeof(buffer - 1));
		cout << "avcodec open failed" << buffer << endl;
		getchar();
		return -1;
	}
	cout << "video avcodec open success" << endl;	
	
	/
	///音频解码器打开
	//