FFmpeg_15_视频流转码（含解复用、解码、编码

extern "C" { #include "libavformat\avformat.h" }; int write_frame(AVFormatContext* pFormatContext,const AVRational* pRational,AVStream* pStream,AVPacket* pPacket) { av_packet_rescale_ts(pPacket,*pRational,pStream->time_base); pPacket->stream_index = pStream->index; return av_interleaved_write_frame(pFormatContext,pPacket); } int write_video_frame(AVFormatContext* pFormatContext,AVStream* pStream,AVFrame* pFrame) { AVCodecContext* pCodecContext = NULL; pCodecContext = pStream->codec; int ret,got_packet = 0; if(pFormatContext->oformat->flags & AVFMT_RAWPICTURE) { AVPacket pPacket = {0}; av_init_packet(&pPacket); if(!pFrame) return 1; pPacket.flags |= AV_PKT_FLAG_KEY; pPacket.stream_index = pStream->index; pPacket.data = (uint8_t *)pFrame; pPacket.size = sizeof(AVPicture); pPacket.pts = pPacket.dts = pFrame->pts; av_packet_rescale_ts(&pPacket,pCodecContext->time_base,pStream->time_base); ret = av_interleaved_write_frame(pFormatContext,&pPacket); } else { AVPacket pPacket = {0}; av_init_packet(&pPacket); ret = avcodec_encode_video2(pCodecContext,&pPacket,pFrame,&got_packet); if(ret < 0) return -1; if(got_packet) ret = write_frame(pFormatContext,&pCodecContext->time_base,pStream,&pPacket); else ret = 0; } if(ret < 0) return -2; return (pFrame || got_packet) ? 0 : 1; } int main() { av_register_all(); //打开输入文件 AVFormatContext *pFormatContext_In = NULL; pFormatContext_In = avformat_alloc_context(); char* FileName_In = "input.ts"; if(avformat_open_input(&pFormatContext_In,FileName_In,NULL,NULL) < 0) { avformat_free_context(pFormatContext_In); return -1; } if(avformat_find_stream_info(pFormatContext_In,NULL) < 0) { avformat_close_input(&pFormatContext_In); return -2; } //获取输入文件视频流索引 int VideoIndex = -1; VideoIndex = av_find_best_stream(pFormatContext_In,AVMEDIA_TYPE_VIDEO,-1,-1,NULL,0); if(VideoIndex == -1) { avformat_close_input(&pFormatContext_In); return -3; } //锁定输出文件格式 AVFormatContext* pFormatContext_Out = NULL; char* FileName_Out = "output.ts"; avformat_alloc_output_context2(&pFormatContext_Out,NULL,NULL,FileName_Out); if(!pFormatContext_Out) { avformat_close_input(&pFormatContext_In); return -4; } AVOutputFormat* pOutputFormat_Out = NULL; pOutputFormat_Out = pFormatContext_Out->oformat; //找到输出文件格式对应的编解码器 AVCodec* pCodec_Out = NULL; pCodec_Out = avcodec_find_encoder(pOutputFormat_Out->video_codec); if(!pCodec_Out) { avformat_free_context(pFormatContext_Out); avformat_close_input(&pFormatContext_In); return -5; } //创建输出流 AVStream* pStream_Out = NULL; pStream_Out = avformat_new_stream(pFormatContext_Out,pCodec_Out); if(!pStream_Out) { avformat_free_context(pFormatContext_Out); avformat_close_input(&pFormatContext_In); return -6; } pStream_Out->id = pFormatContext_Out->nb_streams - 1; //设定输出文件编解码器上下文环境 AVCodecContext* pCodecContext_Out = NULL; pCodecContext_Out = pStream_Out->codec; pCodecContext_Out->codec_id = pOutputFormat_Out->video_codec; pCodecContext_Out->bit_rate = 400000; pCodecContext_Out->width = pFormatContext_In->streams[VideoIndex]->codec->width; pCodecContext_Out->height = pFormatContext_In->streams[VideoIndex]->codec->height; pStream_Out->time_base.num = 1; pStream_Out->time_base.den = 25; pCodecContext_Out->time_base = pStream_Out->time_base; pCodecContext_Out->gop_size = 12; pCodecContext_Out->pix_fmt = AV_PIX_FMT_YUV420P; if(pCodecContext_Out->codec_id == AV_CODEC_ID_MPEG2VIDEO) pCodecContext_Out->max_b_frames = 2; if(pCodecContext_Out->codec_id == AV_CODEC_ID_MPEG1VIDEO) pCodecContext_Out->mb_decision = 2; if(pFormatContext_Out->oformat->flags & AVFMT_GLOBALHEADER) pCodecContext_Out->flags |= CODEC_FLAG_GLOBAL_HEADER; //打开输出文件对应的视频流编解码器 AVDictionary *pDictionary_Out = NULL; av_dict_copy(&pDictionary_Out,NULL,0); if(avcodec_open2(pCodecContext_Out,pCodec_Out,&pDictionary_Out) < 0) { av_dict_free(&pDictionary_Out); avformat_free_context(pFormatContext_Out); avformat_close_input(&pFormatContext_In); return -7; } av_dict_free(&pDictionary_Out); //打开输出文件 int ret = 0; if(!(pOutputFormat_Out->flags & AVFMT_NOFILE)) { ret = avio_open(&pFormatContext_Out->pb,FileName_Out,AVIO_FLAG_WRITE); if(ret < 0) { avcodec_close(pCodecContext_Out); avformat_free_context(pFormatContext_Out); avformat_close_input(&pFormatContext_In); return -8; } } //写输出文件头 ret = avformat_write_header(pFormatContext_Out,&pDictionary_Out); if(ret < 0) { avio_closep(&pFormatContext_Out->pb); avcodec_close(pCodecContext_Out); avformat_free_context(pFormatContext_Out); avformat_close_input(&pFormatContext_In); return -9; } //打开输入文件对应解码器 AVCodecContext* pCodecContext_In = NULL; pCodecContext_In = pFormatContext_In->streams[VideoIndex]->codec; AVCodec* pCodec_In = NULL; pCodec_In = avcodec_find_decoder(pCodecContext_In->codec_id); if(pCodec_In == NULL) { avio_closep(&pFormatContext_Out->pb); avcodec_close(pCodecContext_Out); avformat_free_context(pFormatContext_Out); avformat_close_input(&pFormatContext_In); return -10; } if(avcodec_open2(pCodecContext_In,pCodec_In,nullptr)!=0) { avio_closep(&pFormatContext_Out->pb); avcodec_close(pCodecContext_Out); avformat_free_context(pFormatContext_Out); avformat_close_input(&pFormatContext_In); return -11; } //帧缓存 AVFrame* pFrame = NULL; pFrame = av_frame_alloc(); if(pFrame == NULL) { avio_closep(&pFormatContext_Out->pb); avcodec_close(pCodecContext_Out); avformat_free_context(pFormatContext_Out); avformat_close_input(&pFormatContext_In); return -12; } //数据缓存 AVPacket pPacket; av_init_packet(&pPacket); pPacket.data = NULL; pPacket.size = 0; //解码、编码 int gotFrame = 0; while(1) { if(av_read_frame(pFormatContext_In,&pPacket) >= 0) { if(pPacket.stream_index == VideoIndex) { if((ret = avcodec_decode_video2(pCodecContext_In,pFrame,&gotFrame,&pPacket)) < 0) return ret; if(gotFrame) write_video_frame(pFormatContext_Out,pStream_Out,pFrame); } av_free_packet(&pPacket); } else break; } //写输出文件尾 av_write_trailer(pFormatContext_Out); //释放 av_frame_free(&pFrame); avcodec_close(pCodecContext_In); avio_closep(&pFormatContext_Out->pb); avcodec_close(pCodecContext_Out); avformat_free_context(pFormatContext_Out); avformat_close_input(&pFormatContext_In); system("PAUSE"); return 0; }