整体方案：
采集端：摄像头采集（YUV）->编码（YUV转H264）->写封装（Ｈ264转FLV）->RTMP推流
客户端：RTMP拉流->解封装（FLV转H264）->解码（H264转YUV）->YUV显示（SDL2）
#include <stdio.h>#define __STDC_CONSTANT_MACROS#ifdef _WIN32
//Windows
extern "C"
{
#include "libavformat/avformat.h"
#include "libavutil/mathematics.h"
#include "libavutil/time.h"
};
#else
//Linux...
#ifdef __cplusplus
extern "C"
{
#endif
#include <libavformat/avformat.h>
#include <libavutil/mathematics.h>
#include <libavutil/time.h>
#ifdef __cplusplus
};
#endif
#endif//'1': Use H.264 Bitstream Filter
#define USE_H264BSF 0int main(int argc, char* argv[])
{AVOutputFormat *ofmt = NULL;//Input AVFormatContext and Output AVFormatContextAVFormatContext *ifmt_ctx = NULL, *ofmt_ctx = NULL;AVPacket pkt;const char *in_filename, *out_filename;int ret, i;int videoindex=-1;int frame_index=0;in_filename = "rtmp://192.168.6.139:1935/live/stream";out_filename = "receive.flv";av_register_all();//Networkavformat_network_init();//Inputif ((ret = avformat_open_input(&ifmt_ctx, in_filename, 0, 0)) < 0) {printf( "Could not open input file.");goto end;}if ((ret = avformat_find_stream_info(ifmt_ctx, 0)) < 0) {printf( "Failed to retrieve input stream information");goto end;}for(i=0; i<ifmt_ctx->nb_streams; i++) if(ifmt_ctx->streams[i]->codec->codec_type==AVMEDIA_TYPE_VIDEO){videoindex=i;break;}av_dump_format(ifmt_ctx, 0, in_filename, 0);//Outputavformat_alloc_output_context2(&ofmt_ctx, NULL, NULL, out_filename); //RTMPif (!ofmt_ctx) {printf( "Could not create output context\n");ret = AVERROR_UNKNOWN;goto end;}ofmt = ofmt_ctx->oformat;for (i = 0; i < ifmt_ctx->nb_streams; i++) {//Create output AVStream according to input AVStreamAVStream *in_stream = ifmt_ctx->streams[i];AVStream *out_stream = avformat_new_stream(ofmt_ctx, in_stream->codec->codec);if (!out_stream) {printf( "Failed allocating output stream\n");ret = AVERROR_UNKNOWN;goto end;}//Copy the settings of AVCodecContextret = avcodec_copy_context(out_stream->codec, in_stream->codec);if (ret < 0) {printf( "Failed to copy context from input to output stream codec context\n");goto end;}out_stream->codec->codec_tag = 0;if (ofmt_ctx->oformat->flags & AVFMT_GLOBALHEADER)out_stream->codec->flags |= AV_CODEC_FLAG_GLOBAL_HEADER;}//Dump Format------------------av_dump_format(ofmt_ctx, 0, out_filename, 1);//Open output URLif (!(ofmt->flags & AVFMT_NOFILE)) {ret = avio_open(&ofmt_ctx->pb, out_filename, AVIO_FLAG_WRITE);if (ret < 0) {printf( "Could not open output URL '%s'", out_filename);goto end;}}//Write file headerret = avformat_write_header(ofmt_ctx, NULL);if (ret < 0) {printf( "Error occurred when opening output URL\n");goto end;}#if USE_H264BSFAVBitStreamFilterContext* h264bsfc = av_bitstream_filter_init("h264_mp4toannexb");
#endifwhile (1) {AVStream *in_stream, *out_stream;//Get an AVPacketret = av_read_frame(ifmt_ctx, &pkt);if (ret < 0)break;in_stream = ifmt_ctx->streams[pkt.stream_index];out_stream = ofmt_ctx->streams[pkt.stream_index];/* copy packet *///Convert PTS/DTSpkt.pts = av_rescale_q_rnd(pkt.pts, in_stream->time_base, out_stream->time_base, (AVRounding)(AV_ROUND_NEAR_INF|AV_ROUND_PASS_MINMAX));pkt.dts = av_rescale_q_rnd(pkt.dts, in_stream->time_base, out_stream->time_base, (AVRounding)(AV_ROUND_NEAR_INF|AV_ROUND_PASS_MINMAX));pkt.duration = av_rescale_q(pkt.duration, in_stream->time_base, out_stream->time_base);pkt.pos = -1;//Print to Screenif(pkt.stream_index==videoindex){printf("Receive %8d video frames from input URL\n",frame_index);frame_index++;#if USE_H264BSFav_bitstream_filter_filter(h264bsfc, in_stream->codec, NULL, &pkt.data, &pkt.size, pkt.data, pkt.size, 0);
#endif}//ret = av_write_frame(ofmt_ctx, &pkt);ret = av_interleaved_write_frame(ofmt_ctx, &pkt);if (ret < 0) {printf( "Error muxing packet\n");break;}av_free_packet(&pkt);}#if USE_H264BSFav_bitstream_filter_close(h264bsfc);
#endif//Write file trailerav_write_trailer(ofmt_ctx);
end:avformat_close_input(&ifmt_ctx);/* close output */if (ofmt_ctx && !(ofmt->flags & AVFMT_NOFILE))avio_close(ofmt_ctx->pb);avformat_free_context(ofmt_ctx);if (ret < 0 && ret != AVERROR_EOF) {printf( "Error occurred.\n");return -1;}return 0;
}
)
