其实具体的代码ffmpeg的官方demo做的功能已经很完善了，自己也就修修补补，下面直接上代码
#include "stdafx.h" #include <iostream> #include <stdio.h> #include <tchar.h> //这里是个坑，不加extern "C"，死活编译不过 extern "C" { #include "libavformat/avformat.h" }; using namespace std; int _tmain(int argc, _TCHAR* argv[]) { AVOutputFormat *ofmt = NULL; //创建输入AVFormatContext对象和输出AVFormatContext对象 AVFormatContext *ifmt_ctx = NULL, *ofmt_ctx = NULL; AVPacket pkt; const char *in_filename; int ret, i; int stream_index = 0; int *stream_mapping = NULL; int stream_mapping_size = 0; in_filename = “C:\\test.h264”; //产生对应的录像文件名 SYSTEMTIME systime; GetLocalTime(&systime); char cTime[128]; sprintf(cTime,"M/d/d d:d:d.d\n", systime.wYear,systime.wMonth,systime.wDay,systime.wHour, systime.wMinute, systime.wSecond,systime.wMilliseconds); char out_filename[128]; sprintf_s(out_filename,128,"%s.mp4",cTime); //打开视频文件 if ((ret = avformat_open_input(&ifmt_ctx, in_filename, 0, 0)) < 0) { //LogMessage::DebugLogInfo("ReCode", "打开视频流失败"); return -1; } //获取视频文件信息 if ((ret = avformat_find_stream_info(ifmt_ctx, 0)) < 0) { //LogMessage::DebugLogInfo("ReCode", "获取视频流信息失败"); return -1; } //打印信息 //av_dump_format(ifmt_ctx, 0, in_filename, 0); //输出文件分配空间 avformat_alloc_output_context2(&ofmt_ctx, NULL, NULL, out_filename); if (!ofmt_ctx) { //LogMessage::DebugLogInfo("ReCode", "输出文件分配空间分配失败"); return -1; } stream_mapping_size = ifmt_ctx->nb_streams; stream_mapping = (int *)av_mallocz_array(stream_mapping_size, sizeof(*stream_mapping)); if (!stream_mapping) { //LogMessage::DebugLogInfo("ReCode", "获取mapping失败"); return -1; } ofmt = ofmt_ctx->oformat; for (i = 0; i < ifmt_ctx->nb_streams; i++) { AVStream *out_stream; AVStream *in_stream = ifmt_ctx->streams[i]; AVCodecParameters *in_codecpar = in_stream->codecpar; if (in_codecpar->codec_type != AVMEDIA_TYPE_AUDIO && in_codecpar->codec_type != AVMEDIA_TYPE_VIDEO && in_codecpar->codec_type != AVMEDIA_TYPE_SUBTITLE) { stream_mapping[i] = -1; continue; } stream_mapping[i] = stream_index++; out_stream = avformat_new_stream(ofmt_ctx, NULL); if (!out_stream) { //fprintf(stderr, "Failed allocating output stream\n"); //LogMessage::DebugLogInfo("ReCode", "分配流对象失败"); return -1; } ret = avcodec_parameters_copy(out_stream->codecpar, in_codecpar); if (ret < 0) { //LogMessage::DebugLogInfo("ReCode", "拷贝视频code失败"); return -1; } out_stream->codecpar->codec_tag = 0; } //打开文件 if (!(ofmt->flags & AVFMT_NOFILE)) { ret = avio_open(&ofmt_ctx->pb, out_filename, AVIO_FLAG_WRITE); if (ret < 0) { //LogMessage::DebugLogInfo("ReCode", "打开输出文件失败"); return -1; } } //开始写入文件头 ret = avformat_write_header(ofmt_ctx, NULL); if (ret < 0) { //LogMessage::DebugLogInfo("ReCode", "写入文件头失败"); return -1; } int m_frame_index = 0; //开始读取视频流，并获取pkt信息 while (1) { AVStream *in_stream, *out_stream; ret = av_read_frame(ifmt_ctx, &pkt); if (ret < 0) break; in_stream = ifmt_ctx->streams[pkt.stream_index]; if (pkt.stream_index >= stream_mapping_size || stream_mapping[pkt.stream_index] < 0) { av_packet_unref(&pkt); continue; } pkt.stream_index = stream_mapping[pkt.stream_index]; out_stream = ofmt_ctx->streams[pkt.stream_index]; //从摄像头直接保存的h264文件，重新编码时得自己加时间戳，不然转换出来的是没有时间的 if(pkt.pts==AV_NOPTS_VALUE){ //Write PTS AVRational time_base1=in_stream->time_base; //Duration between 2 frames (us) int64_t calc_duration=(double)AV_TIME_BASE/av_q2d(in_stream->r_frame_rate); //Parameters pkt.pts=(double)(m_frame_index*calc_duration)/(double)(av_q2d(time_base1)*AV_TIME_BASE); pkt.dts=pkt.pts; pkt.duration=(double)calc_duration/(double)(av_q2d(time_base1)*AV_TIME_BASE); } /* copy packet */ pkt.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; ret = av_interleaved_write_frame(ofmt_ctx, &pkt); if (ret < 0) { break; } av_packet_unref(&pkt); m_frame_index++; } av_write_trailer(ofmt_ctx); avformat_close_input(&ifmt_ctx); // close output if (ofmt_ctx && !(ofmt->flags & AVFMT_NOFILE)) avio_closep(&ofmt_ctx->pb); avformat_free_context(ofmt_ctx); av_freep(&stream_mapping); return 0; }
