2023-03-05：ffmpeg推送本地视频至lal流媒体服务器（以RTMP为例），请用go语言编写。

答案2023-03-05：

使用 github.com/moonfdd/ffmpeg-go 库。

先启动lal流媒体服务器软件，然后再执行命令：

go run ./examples/leixiaohua1020/simplest_ffmpeg_streamer/main.go

参考了雷霄骅的最简单的基于FFmpeg的推流器（推送RTMP），代码用golang编写。代码如下：

// https://github.com/leixiaohua1020/simplest_ffmpeg_streamer/blob/master/simplest_ffmpeg_streamer/simplest_ffmpeg_streamer.cpp
package mainimport ("fmt""os""os/exec""time""github.com/moonfdd/ffmpeg-go/ffcommon""github.com/moonfdd/ffmpeg-go/libavcodec""github.com/moonfdd/ffmpeg-go/libavformat""github.com/moonfdd/ffmpeg-go/libavutil"
)func main0() (ret ffcommon.FInt) {var ofmt *libavformat.AVOutputFormat//Input AVFormatContext and Output AVFormatContextvar ifmt_ctx, ofmt_ctx *libavformat.AVFormatContextvar pkt libavcodec.AVPacketvar in_filename, out_filename stringvar i ffcommon.FIntvar videoindex ffcommon.FInt = -1var frame_index ffcommon.FInt = 0var start_time ffcommon.FInt64T = 0var err error//in_filename  = "cuc_ieschool.mov";//in_filename  = "cuc_ieschool.mkv";//in_filename  = "cuc_ieschool.ts";//in_filename  = "cuc_ieschool.mp4";//in_filename  = "cuc_ieschool.h264";in_filename = "./out/cuc_ieschool.flv" //输入URL（Input file URL）//in_filename  = "shanghai03_p.h264";_, err = os.Stat(in_filename)if err != nil {if os.IsNotExist(err) {fmt.Println("create flv file")exec.Command("./lib/ffmpeg", "-i", "./resources/big_buck_bunny.mp4", "-vcodec", "copy", "-acodec", "copy", in_filename).Output()}}out_filename = "rtmp://localhost/publishlive/livestream" //输出 URL（Output URL）[RTMP]//out_filename = "rtp://233.233.233.233:6666";//输出 URL（Output URL）[UDP]libavformat.AvRegisterAll()//Networklibavformat.AvformatNetworkInit()//Inputret = libavformat.AvformatOpenInput(&ifmt_ctx, in_filename, nil, nil)if ret < 0 {fmt.Printf("Could not open input file.")goto end}ret = ifmt_ctx.AvformatFindStreamInfo(nil)if ret < 0 {fmt.Printf("Failed to retrieve input stream information")goto end}for i = 0; i < int32(ifmt_ctx.NbStreams); i++ {if ifmt_ctx.GetStream(uint32(i)).Codec.CodecType == libavutil.AVMEDIA_TYPE_VIDEO {videoindex = ibreak}}ifmt_ctx.AvDumpFormat(0, in_filename, 0)//Outputlibavformat.AvformatAllocOutputContext2(&ofmt_ctx, nil, "flv", out_filename) //RTMP//avformat_alloc_output_context2(&ofmt_ctx, NULL, "mpegts", out_filename);//UDPif ofmt_ctx == nil {fmt.Printf("Could not create output context\n")ret = libavutil.AVERROR_UNKNOWNgoto end}ofmt = ofmt_ctx.Oformatfor i = 0; i < int32(ifmt_ctx.NbStreams); i++ {//Create output AVStream according to input AVStreamin_stream := ifmt_ctx.GetStream(uint32(i))out_stream := ofmt_ctx.AvformatNewStream(in_stream.Codec.Codec)if out_stream == nil {fmt.Printf("Failed allocating output stream\n")ret = libavutil.AVERROR_UNKNOWNgoto end}//Copy the settings of AVCodecContextret = libavcodec.AvcodecCopyContext(out_stream.Codec, in_stream.Codec)if ret < 0 {fmt.Printf("Failed to copy context from input to output stream codec context\n")goto end}out_stream.Codec.CodecTag = 0if ofmt_ctx.Oformat.Flags&libavformat.AVFMT_GLOBALHEADER != 0 {out_stream.Codec.Flags |= libavcodec.AV_CODEC_FLAG_GLOBAL_HEADER}}//Dump Format------------------ofmt_ctx.AvDumpFormat(0, out_filename, 1)//Open output URLif ofmt.Flags&libavformat.AVFMT_NOFILE == 0 {ret = libavformat.AvioOpen(&ofmt_ctx.Pb, out_filename, libavformat.AVIO_FLAG_WRITE)if ret < 0 {fmt.Printf("Could not open output URL '%s'", out_filename)goto end}}//Write file headerret = ofmt_ctx.AvformatWriteHeader(nil)if ret < 0 {fmt.Printf("Error occurred when opening output URL\n")goto end}start_time = libavutil.AvGettime()for {var in_stream, out_stream *libavformat.AVStream//Get an AVPacketret = ifmt_ctx.AvReadFrame(&pkt)if ret < 0 {break}//FIX：No PTS (Example: Raw H.264)//Simple Write PTSif pkt.Pts == libavutil.AV_NOPTS_VALUE {//Write PTStime_base1 := ifmt_ctx.GetStream(uint32(videoindex)).TimeBase//Duration between 2 frames (us)calc_duration := int64(libavutil.AV_TIME_BASE / libavutil.AvQ2d(ifmt_ctx.GetStream(uint32(videoindex)).RFrameRate))//Parameterspkt.Pts = int64(float64(frame_index) * float64(calc_duration) / (libavutil.AvQ2d(time_base1) * libavutil.AV_TIME_BASE))pkt.Dts = pkt.Ptspkt.Duration = int64(float64(calc_duration) / (libavutil.AvQ2d(time_base1) * libavutil.AV_TIME_BASE))}//Important:Delayif pkt.StreamIndex == uint32(videoindex) {time_base := ifmt_ctx.GetStream(uint32(videoindex)).TimeBasetime_base_q := libavutil.AVRational{1, libavutil.AV_TIME_BASE}pts_time := libavutil.AvRescaleQ(pkt.Dts, time_base, time_base_q)now_time := libavutil.AvGettime() - start_timeif pts_time > now_time {libavutil.AvUsleep(uint32(pts_time - now_time))}}in_stream = ifmt_ctx.GetStream(pkt.StreamIndex)out_stream = ofmt_ctx.GetStream(pkt.StreamIndex)/* copy packet *///Convert PTS/DTSpkt.Pts = libavutil.AvRescaleQRnd(pkt.Pts, in_stream.TimeBase, out_stream.TimeBase, libavutil.AV_ROUND_NEAR_INF|libavutil.AV_ROUND_PASS_MINMAX)pkt.Dts = libavutil.AvRescaleQRnd(pkt.Dts, in_stream.TimeBase, out_stream.TimeBase, libavutil.AV_ROUND_NEAR_INF|libavutil.AV_ROUND_PASS_MINMAX)pkt.Duration = libavutil.AvRescaleQ(pkt.Duration, in_stream.TimeBase, out_stream.TimeBase)pkt.Pos = -1//Print to Screenif pkt.StreamIndex == uint32(videoindex) {fmt.Printf("Send %8d video frames to output URL\n", frame_index)frame_index++}//ret = av_write_frame(ofmt_ctx, &pkt);ret = ofmt_ctx.AvInterleavedWriteFrame(&pkt)if ret < 0 {fmt.Printf("Error muxing packet\n")break}pkt.AvFreePacket()}//Write file trailerofmt_ctx.AvWriteTrailer()
end:libavformat.AvformatCloseInput(&ifmt_ctx)/* close output */if ofmt_ctx != nil && ofmt.Flags&libavformat.AVFMT_NOFILE == 0 {ofmt_ctx.Pb.AvioClose()}ofmt_ctx.AvformatFreeContext()if ret < 0 && ret != libavutil.AVERROR_EOF {fmt.Printf("Error occurred.\n")return -1}return 0
}func main() {os.Setenv("Path", os.Getenv("Path")+";./lib")ffcommon.SetAvutilPath("./lib/avutil-56.dll")ffcommon.SetAvcodecPath("./lib/avcodec-58.dll")ffcommon.SetAvdevicePath("./lib/avdevice-58.dll")ffcommon.SetAvfilterPath("./lib/avfilter-56.dll")ffcommon.SetAvformatPath("./lib/avformat-58.dll")ffcommon.SetAvpostprocPath("./lib/postproc-55.dll")ffcommon.SetAvswresamplePath("./lib/swresample-3.dll")ffcommon.SetAvswscalePath("./lib/swscale-5.dll")genDir := "./out"_, err := os.Stat(genDir)if err != nil {if os.IsNotExist(err) {os.Mkdir(genDir, 0777) //  Everyone can read write and execute}}go func() {time.Sleep(1000)exec.Command("./lib/ffplay.exe", "rtmp://localhost/publishlive/livestream").Output()if err != nil {fmt.Println("play err = ", err)}}()main0()
}