ffmpeg开发第一例

站在巨人的肩膀上最简单的基于FFMPEG的封装格式转换器（无编解码）_mp4remuxer_雷霄骅的博客-CSDN博客

在作者的示例上,修正了在ffmpeg6.0.1上运行,有些方法过时了.没有其它的修改.

const char *in_filename = "/Users/archko/Movie/健身气功八段锦-clip.mp4"; const char *out_filename = "/Users/archko/Movie/code.mp4"; const 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; int ret, i; // 输入（Input） ret = avformat_open_input(&ifmt_ctx, in_filename, 0, 0); if (ret < 0) { printf("Could not open input file."); return 0; } ret = avformat_find_stream_info(ifmt_ctx, 0); if (ret < 0) { printf("Failed to retrieve input stream information"); return 0; } 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; return 0; } 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]; const AVCodec *codec = avcodec_find_decoder(in_stream->codecpar->codec_id); AVStream *out_stream = avformat_new_stream(ofmt_ctx, codec); if (!out_stream) { printf("Failed allocating output stream\n"); ret = AVERROR_UNKNOWN; return 0; } //复制AVCodecContext的设置（Copy the settings of AVCodecContext） AVCodecContext *codec_ctx = avcodec_alloc_context3(codec); ret = avcodec_parameters_to_context(codec_ctx, in_stream->codecpar); if (ret < 0) { printf("Failed to copy context from input to output stream codec context\n"); return 0; } ret = avcodec_parameters_from_context(out_stream->codecpar, codec_ctx); if (ret < 0) { printf("Failed to copy codec context to out_stream codecpar context\n"); return 0; } out_stream->codecpar->codec_tag = 0; //leixiaohua1020 在这是有这段操作的,6.0不需要这样,然后正常复制视频 //if (ofmt_ctx->oformat->flags & AVFMT_GLOBALHEADER) { // out_stream->codecpar->codec_tag |= AV_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); return 0; } } //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"); return 0; } 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_packet_unref(&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; } printf("Copy success.\n"); return 0;

xcode的开发实在不习惯,用的是clion,cmake,vscode.下一篇,clion创建项目,导入ffmpeg依赖