Raspberry pi 4b , 基于ffmpeg , 读取rtsp视频流，硬编解码视频流，加水印, 推送RTSP .

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OS 💻​

raspberry pi 4b 8g armv7l GNU/Linux

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搭建 FFmpeg(4.1.1) 环境 ⭐️

1. ⭐️ 安装 x264

   1. 下载 x264 https://ftp.videolan.org/pub/x264/snapshots/

   2. 安装

      ./configure --disable-shared --enable-static --enable-strip --disable-cli
      ./configure --enable-shared --enable-static --enable-strip --disable-cli --prefix=/usr/local/x264
       make -j4 & sudo make install
      

2. ⚡️ 由于需要叠加水印，所以需要安装 freetype、libxml2、fontconfig 、fribidi

   1. 安装 freetype (2.10.0) https://download.savannah.gnu.org/releases/freetype/

       ./configure --prefix=/usr/local/freetype
       make & sudo make install
      

   2. 安装 libxml2 (2.9.9) https://github.com/GNOME/libxml2/tags

      ./configure  --without-python --prefix=/usr/local/libxml2
      make -j4 & sudo make install
      

   3. 安装 fontconfig (2.13.92) https://www.freedesktop.org/software/fontconfig/release/

      autoreconf  -iv
      export PKG_CONFIG_PATH=/usr/local/libxml2/lib/pkgconfig:$PKG_CONFIG_PATH
      export PKG_CONFIG_PATH=/usr/local/freetype/lib/pkgconfig:$PKG_CONFIG_PATH
      ./configure --enable-libxml2 --with-freetype-config=/usr/local/freetype/bin/freetype-config --prefix=/usr/local/fontconfig
       make & sudo make install
      

   4. 安装 fribidi https://github.com/fribidi/fribidi

      1. ./autogen.sh
      2. ./configure --prefix=/usr/local/fribidi
      3. make & sudo make install
      

3. 🌞 安装 ffmpeg

   1. 设置环境变量

      export PKG_CONFIG_PATH=/usr/local/freetype/lib/pkgconfig:$PKG_CONFIG_PATH
      export PKG_CONFIG_PATH=/usr/local/libxml2/lib/pkgconfig:$PKG_CONFIG_PATH
      export PKG_CONFIG_PATH=/usr/local/fontconfig/lib/pkgconfig:$PKG_CONFIG_PATH
      export PKG_CONFIG_PATH=/usr/local/fribidi/lib/pkgconfig:$PKG_CONFIG_PATH
      export PKG_CONFIG_PATH=/usr/local/x264/lib/pkgconfig:$PKG_CONFIG_PATH
      

   2. raspberry 支持硬编解码，所以增加 h264_omx h264_mmal .

      ./configure \
      --enable-gpl --enable-version3 --enable-nonfree \
      --enable-static --enable-shared \
      \
      --prefix=/usr/local/ffmpeg \
      \
      --disable-opencl \
      --disable-thumb \
      --disable-pic \
      --disable-stripping \
      \
      --enable-small \
      \
      --enable-ffmpeg \
      --enable-ffplay \
      --enable-ffprobe \
      \
      --disable-doc \
      --disable-htmlpages \
      --disable-podpages \
      --disable-txtpages \
      --disable-manpages \
      \
      --disable-everything \
      \
      --enable-libx264 \
      --enable-encoder=libx264 \
      --enable-decoder=h264 \
      --enable-encoder=aac \
      --enable-decoder=aac \
      --enable-encoder=ac3 \
      --enable-decoder=ac3 \
      --enable-encoder=rawvideo \
      --enable-decoder=rawvideo \
      --enable-encoder=mjpeg \
      --enable-decoder=mjpeg \
      \
      --enable-demuxer=concat \
      --enable-muxer=flv \
      --enable-demuxer=flv \
      --enable-demuxer=live_flv \
      --enable-muxer=hls \
      --enable-muxer=segment \
      --enable-muxer=stream_segment \
      --enable-muxer=mov \
      --enable-demuxer=mov \
      --enable-muxer=mp4 \
      --enable-muxer=mpegts \
      --enable-demuxer=mpegts \
      --enable-demuxer=mpegvideo \
      --enable-muxer=matroska \
      --enable-demuxer=matroska \
      --enable-muxer=wav \
      --enable-demuxer=wav \
      --enable-muxer=pcm* \
      --enable-demuxer=pcm* \
      --enable-muxer=rawvideo \
      --enable-demuxer=rawvideo \
      --enable-muxer=rtsp \
      --enable-demuxer=rtsp \
      --enable-muxer=rtsp \
      --enable-demuxer=sdp \
      --enable-muxer=fifo \
      --enable-muxer=tee \
      \
      --enable-parser=h264 \
      --enable-parser=aac \
      \
      --enable-protocol=file \
      --enable-protocol=tcp \
      --enable-protocol=rtmp \
      --enable-protocol=cache \
      --enable-protocol=pipe \
      \
      --enable-filter=aresample \
      --enable-filter=allyuv \
      --enable-filter=scale \
      --enable-filter=drawtext \
      --enable-libfreetype \
      \
      --enable-indev=v4l2 \
      --enable-indev=alsa \
      \
      --enable-omx \
      --enable-omx-rpi \
      --enable-encoder=h264_omx \
      \
      --enable-mmal \
      --enable-hwaccel=h264_mmal \
      --enable-decoder=h264_mmal \
      \
      --enable-libfreetype \
      --enable-libfontconfig \
      --enable-libfribidi \
      \
      --enable-encoder=pcm_alaw \
      --enable-decoder=pcm_alaw
      
      make -j & sudo make install
      

   3. 测试

      ./ffmpeg -c:v hx264 -i 2.mp4 -c:v h264_omx -c:a copy -b:v 1500k out2.mp4
      ./ffmpeg -i 2.mp4 -vf "drawtext=fontfile=simsun.ttc: text='aaaa':x=10:y=10:fontsize=24:fontcolor=white:shadowy=2" output.mp4
      

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搭建RTSP 服务器 🤠

1. RTSP 服务器: https://github.com/EasyDarwin/EasyDarwin/releases
2. RTSP 播放器: https://github.com/tsingsee/EasyPlayer-RTSP-Win

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代码实现 🎃

1. 连接 rtsp

int AVFFmpeg::connect(const char* rtsp){
	int ret;
    av_dict_set(&pOptionsDict_, "buffer_size", "409600", 0);
	av_dict_set(&pOptionsDict_, "rtsp_transport", "tcp", 0);
	av_dict_set(&pOptionsDict_, "stimeout", "1000000", 0); 
	av_dict_set(&pOptionsDict_, "max_delay", "500000", 0);
	if ((ret = avformat_open_input(&ifmtCtx_, rtsp, 0, pOptionsDict_ == nullptr ? 0 : &pOptionsDict_)) != 0)
	{
		releaseObj();
		return -1;
	}
	if ((ret = avformat_find_stream_info(ifmtCtx_, NULL)) < 0)
	{
		releaseObj();
		return -1;
	}
	// dump information
	for (unsigned int i = 0; i < ifmtCtx_->nb_streams; i++)
		av_dump_format(ifmtCtx_, i, rtsp, 0);

	findAVStreamIndex(ifmtCtx_, vStreamIndex_, aStreamIndex_);
	if (vStreamIndex_ == -1) {
		releaseObj();
		return -1;
	}
	// decode ctx
	AVStream* pVst = ifmtCtx_->streams[vStreamIndex_];
	pVideoDeCodecCtx_ = createVideoDecoderCtx(pVst);
	if (pVideoDeCodecCtx_ == nullptr)
	{
		releaseObj();
		return -1;
	}
	// encode ctx
	pVideoEnCodecCtx_ = createVideoEncoderCtx(pVst);
	if (pVideoEnCodecCtx_ == nullptr)
	{
		releaseObj();
		return -1;
	}
	isConnected_ = true;
	return 0;
}

2. 创建解码器, 使用硬解码 h264_mmal

AVCodecContext* AVFFmpeg::createVideoDecoderCtx(AVStream* pVst) {
    AVCodec* videoCodec = avcodec_find_decoder_by_name("h264_mmal");
	if (videoCodec == nullptr)
		return nullptr;
	AVCodecContext* codecCtx = avcodec_alloc_context3(videoCodec);
    if (codecCtx == nullptr)
		return nullptr;
	avcodec_parameters_to_context(codecCtx, pVst->codecpar);
    codecCtx->time_base =  {pVst->codec->time_base.num , pVst->codec->time_base.den };
	if (avcodec_open2(codecCtx, videoCodec, NULL) < 0)
	{
		avcodec_free_context(&codecCtx);
		return nullptr;
	}
	return codecCtx;
}

3. 创建编码器 ，使用硬编码 h264_omx

AVCodecContext* AVFFmpeg::createVideoEncoderCtx(AVStream* pVst) {
	AVCodec* codec = avcodec_find_encoder_by_name("h264_omx");
	if (codec == nullptr)
		return nullptr;
	AVCodecContext* codecCtx = avcodec_alloc_context3(codec);
	if (codecCtx == nullptr)
		return nullptr;
	codecCtx->pix_fmt = AV_PIX_FMT_YUV420P;
	codecCtx->width = pVst->codecpar->width;
	codecCtx->height = pVst->codecpar->height;
	codecCtx->bit_rate = 1024000; 
	codecCtx->gop_size = 50; 
	codecCtx->framerate = { pVst->codec->framerate.num, pVst->codec->framerate.den };
	codecCtx->time_base = { pVst->codec->time_base.num, pVst->codec->time_base.den };
	codecCtx->flags |= AV_CODEC_FLAG_GLOBAL_HEADER;
	av_opt_set(codecCtx->priv_data, "tune", "zerolatency", 0);
	if (avcodec_open2(codecCtx, codec, NULL) < 0)
	{
		avcodec_free_context(&codecCtx);
		return nullptr;
	}
	return codecCtx;
}

4. 开启推送rtsp , 推流rtsp地址格式: rtp://ip:port/xx/xx. ip: rtsp 服务器Ip, 端口默认 554。( 如果推送rtmp, 则 “rtsp” -> “flv”)

int AVFFmpeg::startPushStream(const char* url) {
	if (ofmtCtx_ != nullptr)
		return -1;
	int ret;
    // rtmp "rtsp" -> "flv"
	ret = avformat_alloc_output_context2(&ofmtCtx_, NULL, "rtsp", url);
	if (ret < 0)
		return -1;
	// tcp
	av_opt_set(ofmtCtx_->priv_data, "rtsp_transport", "tcp", 0);
	// check if has data ,no data wait max_interleave_delta us.
	ofmtCtx_->max_interleave_delta = 1000000; // us
	ofmtCtx_->max_delay = 100000;
	ret = createPushStream(ifmtCtx_);
	if (ret < 0) {
		avformat_free_context(ofmtCtx_);
		return -1;
	}
	av_dump_format(ofmtCtx_, 0, url, 1);
	if (!(ofmtCtx_->flags & AVFMT_NOFILE)) {
		ret = avio_open(&ofmtCtx_->pb, url, AVIO_FLAG_WRITE);
		if (ret < 0) {
			avformat_free_context(ofmtCtx_);
			return -1;
		}
	}
	ofmtCtx_->video_codec_id = ofmtCtx_->oformat->video_codec;
	if(avformat_write_header(ofmtCtx_, NULL) < 0){
		avformat_free_context(ofmtCtx_);
		return -1;
	}
	mStartPushStream_ = true;
	return 0;
}

5. 加水印文字，目前设置四个角

AVFrame* AVOSD::setOSDInfo(AVFrame* frame, int width, int height, OSDInfo& info) {
	AVFilterContext* buffersink_ctx;
	AVFilterContext* buffersrc_ctx;
	// osd
	AVFilterGraph* filter_graph = get_filter_graph(frame, width, height, &buffersink_ctx, &buffersrc_ctx, info);
	if (filter_graph == nullptr)
		return nullptr;
	int ret = av_buffersrc_add_frame(buffersrc_ctx, frame);
	if (ret < 0)
	{
		avfilter_graph_free(&filter_graph);
		filter_graph = NULL;
		return nullptr;
	}
	AVFrame* out = av_frame_alloc();
	ret = av_buffersink_get_frame(buffersink_ctx, out);
	avfilter_graph_free(&filter_graph);
	filter_graph = NULL;
	if (ret < 0)
	{
		av_frame_free(&out);
		return nullptr;
	}
	return out;
}

6. 实现预览推送

int AVFFmpeg::startRealPlay(){
	if(!isConnected_)
		return -1;
	int ret;
    mStartRealPlay_ = true;
	bool flag = false;
	AVPacket pkt;
	av_init_packet(&pkt);
	while (mStartRealPlay_)
	{
		ret = av_read_frame(ifmtCtx_, &pkt);
		if (ret < 0)
		{   // disconnect
			av_packet_unref(&pkt);
			releaseObj();
			break;
		}
		// audio
		if (pkt.stream_index == aStreamIndex_) {
			av_packet_unref(&pkt);
			continue;
		}
		// decode packet to frame
		AVFrame* in = decodePacketToFrame(pVideoDeCodecCtx_, pkt, ret);
		av_packet_unref(&pkt);
		if (ret != 0)
			continue;
		int srcW = pVideoDeCodecCtx_->width;
		int srcH = pVideoDeCodecCtx_->height;
		// add osd info to frame
		AVFrame* out = pOSD_->setOSDInfo(in, srcW, srcH, osdInfo_);
		av_frame_free(&in);
		if (out == nullptr)
			continue;
        // push stream
		if(mStartPushStream_){
			AVPacket* epkt= av_packet_alloc();
			int ret = avcodec_send_frame(pVideoEnCodecCtx_, out);
			if (ret == 0){
				while(avcodec_receive_packet(pVideoEnCodecCtx_, epkt)>=0){
					ret = writePushStream(epkt);
				}
			}
			av_packet_free(&epkt);
		}
		av_frame_free(&out);
	}
    stopPushStream();
	isStopPreview_ = true;
	return 0;
}

7. main

int main(){

    pthread_t tids[1];
    const char* rtspUrl = "rtsp://xxxxxxxx"; 
    const char* pushUrl = "rtp://user:pwd@ip:port/xxxxx";

    int ret = avFm_.connect(rtspUrl);
    if(ret != 0)
    {
        std::cout << "rtsp connect failed..." << std::endl;
        return -1;
    }

     ret = pthread_create(&tids[0], NULL, connect_rtsp, NULL);
    if (ret != 0)
    {
        avFm_.disconnect();
        std::cout << "pthread_create error: error_code=" << ret << std::endl;
        return -1;
    }
    usleep(5000000);
    std::cout << "start push : " << pushUrl << std::endl;
    ret = avFm_.startPushStream(pushUrl);    
    if(ret != 0)
    {
        std::cout << "startPushStream failed..." << std::endl;
        return -1;
    }
    usleep(30000000);
    std::cout << "stop push.... " << std::endl;
    avFm_.stopPushStream(); 
    usleep(1000000);
    std::cout << "stop real play .... " << std::endl;
    avFm_.stopRealPlay();
    usleep(1000000);
    std::cout << "disconnect .... " << std::endl;
    avFm_.disconnect();
    std::cout << "finish .... " << std::endl;
    return 0;
}

8. 以上是部分实现代码，有需要的小伙伴可以参考参考. 完整代码: https://download.csdn.net/download/haiyangyunbao813/85149687

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Q&A 👨‍🚀​

1. ERROR: OMX_Core.h not found

   sudo apt-get install libomxil-bellagio-dev
   

2. avcodec_open2 阻塞不动 , mmal error 2 on control port , OMX error 80001000

   修改 /boot/config.txt 
   [all]
   #dtoverlay=vc4-fkms-v3d
   gpu_mem=512
   ---
   sudo reboot
   

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Demo: ✨​

• https://download.csdn.net/download/haiyangyunbao813/85149687

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参考文章 📖

1. https://www.jianshu.com/p/dec9bf9cffc9
2. https://blog.csdn.net/Tang_Chuanlin/article/details/85244429
3. https://www.willusher.io/general/2020/11/15/hw-accel-encoding-rpi4
4. https://its401.com/article/wanggao_1990/116195910
5. https://qa.icopy.site/questions/60529213/how-to-enable-hardware-support-for-h-264-encoding-on-raspberry-pi-4b

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END🔚​

1. 以上基本是我整理得全部内容了，有不对得地方，欢迎大家留言指正，感谢。 🤔

2. 码字不易，纯手工输出，感觉有一丢丢有用，麻烦给个好评呗。 😂