RK3568使用C++和FFmpeg进行视频流，并使用自带GPU加速

在RK3568平台上使用C++和FFmpeg进行视频流处理时，可以利用GPU加速解码。RK3568芯片集成了Mali-G52 GPU，支持硬件加速的视频解码。以下是一个基本的示例，展示如何使用FFmpeg和RK3568的GPU加速来拉取视频流。

1. 安装FFmpeg和RKMPP

首先，确保你已经安装了FFmpeg和RKMPP（Rockchip Media Process Platform）。RKMPP是Rockchip提供的用于硬件加速的库。

sudo apt-get update
sudo apt-get install ffmpeg
sudo apt-get install librkmpp-dev

2. 编写C++代码

以下是一个简单的C++代码示例，展示如何使用FFmpeg和RKMPP来拉取视频流并进行硬件加速解码。

extern "C" {
#include <libavcodec/avcodec.h>
#include <libavformat/avformat.h>
#include <libavutil/hwcontext.h>
#include <libavutil/error.h>
#include <libavutil/imgutils.h>
#include <libavutil/opt.h>
#include <libswscale/swscale.h>
}#include <iostream>
#include <stdexcept>#define HARDWARE_DEVICE_TYPE AV_HWDEVICE_TYPE_DRMvoid handle_error(int errnum) {char errbuf[AV_ERROR_MAX_STRING_SIZE];av_strerror(errnum, errbuf, sizeof(errbuf));throw std::runtime_error(errbuf);
}int main(int argc, char* argv[]) {if (argc < 2) {std::cerr << "Usage: " << argv[0] << " <input_url>" << std::endl;return 1;}const char* input_url = argv[1];av_register_all();avformat_network_init();AVFormatContext* format_ctx = avformat_alloc_context();if (!format_ctx) {std::cerr << "Could not allocate format context" << std::endl;return 1;}if (avformat_open_input(&format_ctx, input_url, nullptr, nullptr) < 0) {std::cerr << "Could not open input " << input_url << std::endl;return 1;}if (avformat_find_stream_info(format_ctx, nullptr) < 0) {std::cerr << "Could not find stream information" << std::endl;return 1;}int video_stream_index = -1;for (unsigned int i = 0; i < format_ctx->nb_streams; i++) {if (format_ctx->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {video_stream_index = i;break;}}if (video_stream_index == -1) {std::cerr << "Could not find video stream" << std::endl;return 1;}AVCodecParameters* codec_params = format_ctx->streams[video_stream_index]->codecpar;const AVCodec* codec = avcodec_find_decoder(codec_params->codec_id);if (!codec) {std::cerr << "Unsupported codec" << std::endl;return 1;}AVCodecContext* codec_ctx = avcodec_alloc_context3(codec);if (!codec_ctx) {std::cerr << "Could not allocate codec context" << std::endl;return 1;}if (avcodec_parameters_to_context(codec_ctx, codec_params) < 0) {std::cerr << "Could not copy codec parameters to context" << std::endl;return 1;}AVBufferRef* hw_device_ctx = nullptr;if (av_hwdevice_ctx_create(&hw_device_ctx, HARDWARE_DEVICE_TYPE, nullptr, nullptr, 0) < 0) {std::cerr << "Could not create hardware device context" << std::endl;return 1;}codec_ctx->hw_device_ctx = av_buffer_ref(hw_device_ctx);if (avcodec_open2(codec_ctx, codec, nullptr) < 0) {std::cerr << "Could not open codec" << std::endl;return 1;}AVFrame* frame = av_frame_alloc();AVFrame* sw_frame = av_frame_alloc();if (!frame || !sw_frame) {std::cerr << "Could not allocate frames" << std::endl;return 1;}AVPacket packet;while (av_read_frame(format_ctx, &packet) >= 0) {if (packet.stream_index == video_stream_index) {if (avcodec_send_packet(codec_ctx, &packet) < 0) {std::cerr << "Error sending packet for decoding" << std::endl;break;}while (avcodec_receive_frame(codec_ctx, frame) >= 0) {if (frame->format == AV_PIX_FMT_DRM_PRIME) {if (av_hwframe_transfer_data(sw_frame, frame, 0) < 0) {std::cerr << "Error transferring data to software frame" << std::endl;break;}// Process sw_frame herestd::cout << "Frame decoded: " << sw_frame->width << "x" << sw_frame->height << std::endl;}}}av_packet_unref(&packet);}av_frame_free(&frame);av_frame_free(&sw_frame);avcodec_free_context(&codec_ctx);avformat_close_input(&format_ctx);av_buffer_unref(&hw_device_ctx);return 0;
}