下面贴上代码,代码是从FFmpeg的例子改编的,平台是VC2010。
/* *最简单的基于FFmpeg的封装格式转换器 *Simplest FFmpeg Remuxer * *雷霄骅 Lei Xiaohua *leixiaohua1020@126.com *中国传媒大学/数字电视技术 *Communication University of China / Digital TV Technology *http://blog.csdn.net/leixiaohua1020 * *本程序实现了视频封装格式之间的转换。 *需要注意的是本程序并不改变视音频的编码格式。 * * This software converts a media file from one container format * to another container format without encoding/decoding video files. */ #include "stdafx.h" extern "C" { #include "libavformat/avformat.h" }; int _tmain(int argc, _TCHAR* argv[]) { AVOutputFormat *ofmt = NULL; //输入对应一个AVFormatContext,输出对应一个AVFormatContext //(Input AVFormatContext and Output AVFormatContext) AVFormatContext *ifmt_ctx = NULL, *ofmt_ctx = NULL; AVPacket pkt; const char *in_filename, *out_filename; int ret, i; if (argc < 3) { printf("usage: %s input output\n" "Remux a media file with libavformat and libavcodec.\n" "The output format is guessed according to the file extension.\n" "Modified by Lei Xiaohua, leixiaohua1020@126.com\n" "Communication University of China / Digital TV Technology\n" "http://blog.csdn.net/leixiaohua1020", argv[0]); return 1; } in_filename = argv[1];//输入文件名(Input file URL) out_filename = argv[2];//输出文件名(Output file URL) av_register_all(); //输入(Input) if ((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; } av_dump_format(ifmt_ctx, 0, in_filename, 0); //输出(Output) avformat_alloc_output_context2(&ofmt_ctx, NULL, NULL, out_filename); if (!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++) { //根据输入流创建输出流(Create output AVStream according to input AVStream) AVStream *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; } //复制AVCodecContext的设置(Copy the settings of AVCodecContext) ret = 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 |= CODEC_FLAG_GLOBAL_HEADER; } //输出一下格式------------------ av_dump_format(ofmt_ctx, 0, out_filename, 1); //打开输出文件(Open output file) if (!(ofmt->flags & AVFMT_NOFILE)) { ret = avio_open(&ofmt_ctx->pb, out_filename, AVIO_FLAG_WRITE); if (ret < 0) { printf( "Could not open output file ‘%s‘", out_filename); goto end; } } //写文件头(Write file header) ret = avformat_write_header(ofmt_ctx, NULL); if (ret < 0) { printf( "Error occurred when opening output file\n"); goto end; } int frame_index=0; while (1) { AVStream *in_stream, *out_stream; //获取一个AVPacket(Get an AVPacket) ret = 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 */ //转换PTS/DTS(Convert PTS/DTS) 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; //写入(Write) ret = av_interleaved_write_frame(ofmt_ctx, &pkt); if (ret < 0) { printf( "Error muxing packet\n"); break; } printf("Write %8d frames to output file\n",frame_index); av_free_packet(&pkt); frame_index++; } //写文件尾(Write file trailer) av_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; }
完整工程下载地址:
http://download.csdn.net/detail/leixiaohua1020/7323491
最简单的基于FFmpeg的封装格式转换器(无编解码),布布扣,bubuko.com
原文地址:http://blog.csdn.net/leixiaohua1020/article/details/25422685