FFmpeg视频、音频复用（VC2010）

extern "C" { #include "libavformat\avformat.h" }; //将视频流和音频流封装成多媒体文件 void StreamToMedia(char *Path_I_V,char *Path_I_A,char *Path_O) { //结构体AVFormatContext -- 包含了多媒体流的格式内容 //打开、查找输入的视频流 AVFormatContext *pFormatContext_I_V = NULL; if(avformat_open_input(&pFormatContext_I_V,Path_I_V,0,0) < 0) goto end; if(avformat_find_stream_info(pFormatContext_I_V,0) < 0) goto end; //打开、查找输入的音频流 AVFormatContext *pFormatContext_I_A = NULL; if(avformat_open_input(&pFormatContext_I_A,Path_I_A,0,0) < 0) goto end; if(avformat_find_stream_info(pFormatContext_I_A,0) < 0) goto end; //初始化一个用于输出的结构体AVFormatContext，并猜测其输出数据的格式 AVFormatContext *pFormatContext_O = NULL; avformat_alloc_output_context2(&pFormatContext_O,NULL,NULL,Path_O); if(pFormatContext_O == NULL) goto end; //结构体AVOutputFormat -- 存储输出数据的封装格式 AVOutputFormat *pOutputFormat = NULL; //struct AVOutputFormat *oformat -- 结构体AVFormatContext的参数 pOutputFormat = pFormatContext_O->oformat; //获取视频流输入索引，创建对应输出视频流并设置其输出索引、编码器上下文等参数 int i = 0,VideoIndex_I = -1,VideoIndex_O = -1; for(i=0;i<pFormatContext_I_V->nb_streams;i++) { if(pFormatContext_I_V->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO) { //获得视频流输入索引 VideoIndex_I = i; //结构体AVStream -- 存储视频/音频流信息 AVStream *StreamIn = pFormatContext_I_V->streams[i]; //以输入的流所使用的编码器创建一条输出流，每次创建都会生成对应的新的索引 AVStream *StreamOut = avformat_new_stream(pFormatContext_O,StreamIn->codec->codec); if(!StreamOut) goto end; //获取生成的输出多媒体流中视/音频流的索引 VideoIndex_O = StreamOut->index; //将输入视频/音频的参数拷贝至输出视频/音频的AVCodecContext结构体 if(avcodec_copy_context(StreamOut->codec,StreamIn->codec) < 0) goto end; StreamOut->codec->codec_tag = 0; if(pFormatContext_O->oformat->flags & AVFMT_GLOBALHEADER) StreamOut->codec->flags |= CODEC_FLAG_GLOBAL_HEADER; break; } } //获取音频流输入索引，创建对应输出音频流并设置其输出索引、编码器上下文等参数 int AudioIndex_I = -1,AudioIndex_O = -1; for(i=0;i<pFormatContext_I_A->nb_streams;i++) { if(pFormatContext_I_A->streams[i]->codec->codec_type == AVMEDIA_TYPE_AUDIO) { //获得音频流输入索引 AudioIndex_I = i; AVStream *StreamIn = pFormatContext_I_A->streams[i]; AVStream *StreamOut = avformat_new_stream(pFormatContext_O,StreamIn->codec->codec); if(!StreamOut) goto end; AudioIndex_O = StreamOut->index; if(avcodec_copy_context(StreamOut->codec,StreamIn->codec) < 0) goto end; StreamOut->codec->codec_tag = 0; if(pFormatContext_O->oformat->flags & AVFMT_GLOBALHEADER) StreamOut->codec->flags |= CODEC_FLAG_GLOBAL_HEADER; break; } } //打开多媒体流输出文件 if(!(pOutputFormat->flags & AVFMT_NOFILE)) if(avio_open(&pFormatContext_O->pb,Path_O,AVIO_FLAG_WRITE) < 0) goto end; //写多媒体流输出文件的文件头 if(avformat_write_header(pFormatContext_O,NULL) < 0) goto end; //对于某些封装格式（例如MP4/FLV/MKV等）中的H.264，需要用到名称为“h264_mp4toannexb”的bitstream filter AVBitStreamFilterContext* h264bsfc = av_bitstream_filter_init("h264_mp4toannexb"); //对于某些封装格式（例如MP4/FLV/MKV等）中的AAC，需要用到名称为“aac_adtstoasc”的bitstream filter AVBitStreamFilterContext* aacbsfc = av_bitstream_filter_init("aac_adtstoasc"); //定义AVPacket数据缓存区 AVPacket pPacket; //定义输出流每一帧数据在处理中的索引值，以处理时间戳 int StreamFrameIndex = 0; int64_t ts_a = 0,ts_b = 0; //循环写多媒体流输出文件的内容，直到写完为止 while(1) { AVStream *StreamIn,*StreamOut; int StreamIndex = 0; //av_compare_ts() -- 比较时间戳，决定写入视频还是写入音频 if(av_compare_ts(ts_a,pFormatContext_I_V->streams[VideoIndex_I]->time_base,ts_b,pFormatContext_I_A->streams[AudioIndex_I]->time_base) <= 0) { StreamIndex = VideoIndex_O; //av_read_frame() -- 从输入流中取出相应流的AVPacket if(av_read_frame(pFormatContext_I_V,&pPacket) >= 0) { do{ StreamIn = pFormatContext_I_V->streams[pPacket.stream_index]; StreamOut = pFormatContext_O->streams[VideoIndex_O]; //判断当前AVPacket数据是否为视频流 if(pPacket.stream_index == VideoIndex_I) { //如果当前AVPacket数据并无pts值，则运算求出 if(pPacket.pts == AV_NOPTS_VALUE) { //结构体AVRational -- 时间基本单位，在条件（以秒为单位）帧时间戳派代表出席了会议 AVRational TimeBase = StreamIn->time_base; //计算两帧之间时长（单位微秒），如1秒25帧就会得出40000微秒 int64_t Duration = (double)AV_TIME_BASE/av_q2d(StreamIn->r_frame_rate); //计算当前AVPacket数据的显示时间戳 pPacket.pts = (double)(StreamFrameIndex*Duration)/(double)(av_q2d(TimeBase)*AV_TIME_BASE); //计算当前AVPacket数据的解码时间戳 pPacket.dts = pPacket.pts; //计算当前AVPacket数据的时长 pPacket.duration=(double)Duration/(double)(av_q2d(TimeBase)*AV_TIME_BASE); StreamFrameIndex++; } ts_a = pPacket.pts; break; } }while(av_read_frame(pFormatContext_I_V,&pPacket) >= 0); } else break; } else { StreamIndex = AudioIndex_O; if(av_read_frame(pFormatContext_I_A,&pPacket) >= 0) { do{ StreamIn = pFormatContext_I_A->streams[pPacket.stream_index]; StreamOut = pFormatContext_O->streams[AudioIndex_O]; //判断当前AVPacket数据是否为音频流 if(pPacket.stream_index == AudioIndex_I) { if(pPacket.pts == AV_NOPTS_VALUE) { AVRational TimeBase = StreamIn->time_base; int64_t Duration = (double)AV_TIME_BASE/av_q2d(StreamIn->r_frame_rate); pPacket.pts = (double)(StreamFrameIndex*Duration)/(double)(av_q2d(TimeBase)*AV_TIME_BASE); pPacket.dts = pPacket.pts; pPacket.duration=(double)Duration/(double)(av_q2d(TimeBase)*AV_TIME_BASE); StreamFrameIndex++; } ts_b = pPacket.pts; break; } }while(av_read_frame(pFormatContext_I_A,&pPacket) >= 0); } else break; } //使用filter转换 av_bitstream_filter_filter(h264bsfc,StreamOut->codec,NULL,&pPacket.data,&pPacket.size,pPacket.data,pPacket.size,0); av_bitstream_filter_filter(aacbsfc,StreamOut->codec,NULL,&pPacket.data,&pPacket.size,pPacket.data,pPacket.size,0); //int64_t pts -- 显示时间戳 pPacket.pts = av_rescale_q_rnd(pPacket.pts,StreamIn->time_base,StreamOut->time_base,(AVRounding)(AV_ROUND_NEAR_INF|AV_ROUND_PASS_MINMAX)); //int64_t dts -- 解码时间戳 pPacket.dts = av_rescale_q_rnd(pPacket.dts,StreamIn->time_base,StreamOut->time_base,(AVRounding)(AV_ROUND_NEAR_INF|AV_ROUND_PASS_MINMAX)); //int duration -- 数据的时长，以所属媒体流的时间基准为单位 pPacket.duration = av_rescale_q(pPacket.duration,StreamIn->time_base,StreamOut->time_base); //int64_t pos -- 该数据在媒体流中的字节偏移量 pPacket.pos = -1; //int stream_index -- 所属媒体流的索引 pPacket.stream_index = StreamIndex; //写入一个AVPacket到输出文件 if(av_interleaved_write_frame(pFormatContext_O,&pPacket) < 0) break; //清空AVPacket结构体数据 av_free_packet(&pPacket); } //写多媒体流输出文件的文件尾 av_write_trailer(pFormatContext_O); //关闭filter av_bitstream_filter_close(h264bsfc); av_bitstream_filter_close(aacbsfc); end: //资源释放 avio_close(pFormatContext_O->pb); avformat_free_context(pFormatContext_O); avformat_close_input(&pFormatContext_I_A); avformat_close_input(&pFormatContext_I_V); } int main(int argc,char **argv) { //注册所有的文件格式和编解码器 av_register_all(); StreamToMedia("Video.h264","Audio.aac","Media.mp4"); return 0; }