FFmpeg解封装音视频分离：
参考：http://blog.csdn.net/leixiaohua1020/article/details/39802819
// ffmpeg_test // 2016.2.28 /* FFmpeg环境配置： 配置包含目录，库目录，附加依赖性 添加dll到工程debug文件下 */ /* libavcodec encoding/decoding library libavfilter graph-based frame editing library libavformat I/O and muxing/demuxing library libavdevice special devices muxing/demuxing library libavutil common utility library libswresample audio resampling, format conversion and mixing libpostproc post processing library libswscale color conversion and scaling library */ #include <cstdio> extern "C" // 因为FFmpeg是纯C程序 { // FFmpeg libraries #include "libavcodec/avcodec.h" #include "libavformat/avformat.h" #include "libswscale/swscale.h" }; ///////////////////////////////////////////////////////////////////////////////////////// // 解封装，音视频分离 int main(int argc, char* argv[]) { AVFormatContext *ifmt_ctx = NULL, *ofmt_ctx_audio = NULL, *ofmt_ctx_video = NULL; AVPacket pkt; AVOutputFormat *ofmt_audio = NULL, *ofmt_video = NULL; int videoindex = -1, audioindex = -1; int frame_index = 0; const char *in_filename = "荷塘月色.mkv"; const char *out_filename_video = "荷塘月色.h264"; const char *out_filename_audio = "荷塘月色.aac"; av_register_all(); if (avformat_open_input(&ifmt_ctx, in_filename, NULL, NULL) != 0) { printf_s("Couldn't open input file. "); return -1; } if (avformat_find_stream_info(ifmt_ctx, NULL) < 0) { printf_s("Couldn't find stream information. "); return -1; } // Allocate an AVFormatContext for an output format avformat_alloc_output_context2(&ofmt_ctx_video, NULL, NULL, out_filename_video); if (!ofmt_ctx_video) { printf_s("Couldn't create output context. "); return -1; } ofmt_video = ofmt_ctx_video->oformat; avformat_alloc_output_context2(&ofmt_ctx_audio, NULL, NULL, out_filename_audio); if (!ofmt_ctx_audio) { printf_s("Couldn't create output context. "); return -1; } ofmt_audio = ofmt_ctx_audio->oformat; // 一般情况下nb_streams只有两个流，就是streams[0],streams[1]，分别是音频和视频流，不过顺序不定 for (int i = 0; i < ifmt_ctx->nb_streams; i++) { AVFormatContext *ofmt_ctx; AVStream *in_stream = ifmt_ctx->streams[i]; AVStream *out_stream = NULL; // 根据音视频类型，根据输入流创建输出流 if (ifmt_ctx->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO) { videoindex = i; out_stream = avformat_new_stream(ofmt_ctx_video, in_stream->codec->codec); ofmt_ctx = ofmt_ctx_video; } else if (ifmt_ctx->streams[i]->codec->codec_type == AVMEDIA_TYPE_AUDIO) { audioindex = i; out_stream = avformat_new_stream(ofmt_ctx_audio, in_stream->codec->codec); ofmt_ctx = ofmt_ctx_audio; } else break; if (!out_stream) { printf_s("Failed allocating output stream. "); return -1; } // 复制到输出流 if (avcodec_copy_context(out_stream->codec, in_stream->codec) < 0) { printf_s("Failed to copy context from input to output stream codec context. "); return -1; } out_stream->codec->codec_tag = 0; if (ofmt_ctx->oformat->flags & AVFMT_GLOBALHEADER) out_stream->codec->flags |= CODEC_FLAG_GLOBAL_HEADER; } // Print detailed information about the input or output format printf_s(" ==============Input Video============= "); av_dump_format(ifmt_ctx, 0, in_filename, 0); printf_s(" ==============Output Video============ "); av_dump_format(ofmt_ctx_video, 0, out_filename_video, 1); printf_s(" ==============Output Audio============ "); av_dump_format(ofmt_ctx_audio, 0, out_filename_audio, 1); printf_s(" ====================================== "); // 打开输出文件 if (!(ofmt_video->flags & AVFMT_NOFILE)) { if (avio_open(&ofmt_ctx_video->pb, out_filename_video, AVIO_FLAG_WRITE) < 0) { printf_s("Couldn't open output file '%s'", out_filename_video); return -1; } } if (!(ofmt_audio->flags & AVFMT_NOFILE)) { if (avio_open(&ofmt_ctx_audio->pb, out_filename_audio, AVIO_FLAG_WRITE) < 0) { printf_s("Couldn't open output file '%s'", out_filename_audio); return -1; } } // 写文件头部 if (avformat_write_header(ofmt_ctx_video, NULL) < 0) { printf_s("Error occurred when opening video output file "); return -1; } if (avformat_write_header(ofmt_ctx_audio, NULL) < 0) { printf_s("Error occurred when opening video output file "); return -1; } // 分离某些封装格式（例如MP4/FLV/MKV等）中的H.264的时候，需要首先写入SPS和PPS，否则会导致分离出来的数据 // 没有SPS、PPS而无法播放。使用ffmpeg中名称为“h264_mp4toannexb”的bitstream filter处理 AVBitStreamFilterContext *h264bsfc = av_bitstream_filter_init("h264_mp4toannexb"); while (1) { AVFormatContext *ofmt_ctx; AVStream *in_stream, *out_stream; //Get an AVPacket if (av_read_frame(ifmt_ctx, &pkt) < 0) break; in_stream = ifmt_ctx->streams[pkt.stream_index]; // stream_index标识该AVPacket所属的视频/音频流 if (pkt.stream_index == videoindex) { // 前面已经通过avcodec_copy_context()函数把输入视频/音频的参数拷贝至输出视频/音频的AVCodecContext结构体 // 所以使用的就是ofmt_ctx_video的第一个流streams[0] out_stream = ofmt_ctx_video->streams[0]; ofmt_ctx = ofmt_ctx_video; printf_s("Write Video Packet. size:%d pts:%lld ", pkt.size, pkt.pts); av_bitstream_filter_filter(h264bsfc, in_stream->codec, NULL, &pkt.data, &pkt.size, pkt.data, pkt.size, 0); } else if (pkt.stream_index == audioindex) { out_stream = ofmt_ctx_audio->streams[0]; ofmt_ctx = ofmt_ctx_audio; printf_s("Write Audio Packet. size:%d pts:%lld ", pkt.size, pkt.pts); } else continue; // DTS（Decoding Time Stamp）解码时间戳 // PTS（Presentation Time Stamp）显示时间戳 // 转换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; pkt.stream_index = 0; // 写 if (av_interleaved_write_frame(ofmt_ctx, &pkt) < 0) { printf_s("Error muxing packet "); break; } printf_s("Write %8d frames to output file ",frame_index); av_free_packet(&pkt); frame_index++; } av_bitstream_filter_close(h264bsfc); // 写文件尾部 av_write_trailer(ofmt_ctx_video); av_write_trailer(ofmt_ctx_audio); avformat_close_input(&ifmt_ctx); if (ofmt_ctx_video && !(ofmt_video->flags & AVFMT_NOFILE)) avio_close(ofmt_ctx_video->pb); if (ofmt_ctx_audio && !(ofmt_audio->flags & AVFMT_NOFILE)) avio_close(ofmt_ctx_audio->pb); avformat_free_context(ofmt_ctx_video); avformat_free_context(ofmt_ctx_audio); return 0; }