在FFmpeg中获取MacroBlock信息

AVFormatContext *formatContext;
avformat_open_input(&formatContext, "input.mp4", NULL, NULL);
avformat_find_stream_info(formatContext, NULL);
int videoStreamIndex = av_find_best_stream(formatContext, AVMEDIA_TYPE_VIDEO, -1, -1, NULL, 0);
AVCodecParameters *codecParameters = formatContext->streams[videoStreamIndex]->codecpar;

AVCodec *codec = avcodec_find_decoder(codecParameters->codec_id);
AVCodecContext *codecContext = avcodec_alloc_context3(codec);
avcodec_parameters_to_context(codecContext, codecParameters);
avcodec_open2(codecContext, codec, NULL);

AVPacket *packet = av_packet_alloc();
AVFrame *frame = av_frame_alloc();
while (av_read_frame(formatContext, packet) >= 0) {
    if (packet->stream_index == videoStreamIndex) {
        avcodec_send_packet(codecContext, packet);
        avcodec_receive_frame(codecContext, frame);
        
        // 在这里处理解码后的视频帧，获取MacroBlock信息
    }
    av_packet_unref(packet);
}

int mbWidth = (codecContext->width + 15) / 16;
int mbHeight = (codecContext->height + 15) / 16;
for (int mbY = 0; mbY < mbHeight; mbY++) {
    for (int mbX = 0; mbX < mbWidth; mbX++) {
        // 获取宏块的相关信息
        int mbIndex = mbY * mbWidth + mbX;
        int mbXPos = mbX * 16;
        int mbYPos = mbY * 16;
        
        // 在这里可以根据需要处理宏块信息
    }
}