音视频

核心代码

找其中一个源文件的音频流

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for(int i = 0; i < ifmt1->nb_streams; i++){
    AVStream *instream1 = ifmt1->streams[i];
    AVStream *outstream = NULL;
    AVCodecParameters *inCodecPar1 = instream1->codecpar;

    if(inCodecPar1->codec_type == AVMEDIA_TYPE_AUDIO){
        outstream = avformat_new_stream(ofmt, NULL);
        if(!outstream){
            av_log(NULL, AV_LOG_ERROR, "创建流失败!");
            goto __ERROR;
        }
        avcodec_parameters_copy(outstream->codecpar, instream1->codecpar);
        outstream->codecpar->codec_tag = 0;
        aidx = i;
        aidx1 = cnt++;
    }
}

找另一个源文件的视频流

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for(int i = 0; i < ifmt2->nb_streams; i++){
    AVStream *instream2 = ifmt2->streams[i];
    AVStream *outstream = NULL;
    AVCodecParameters *inCodecPar2 = instream2->codecpar;

    if(inCodecPar2->codec_type == AVMEDIA_TYPE_VIDEO){
        outstream = avformat_new_stream(ofmt, NULL);
        if(!outstream){
            av_log(NULL, AV_LOG_ERROR, "创建流失败!");
            goto __ERROR;
        }
        avcodec_parameters_copy(outstream->codecpar, instream2->codecpar);
        outstream->codecpar->codec_tag = 0;
        vidx = i;
        vidx1 = cnt++;
    }
}

读取源文件并写入到目标文件

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while(av_read_frame(ifmt1, &pkt1) >= 0 || av_read_frame(ifmt2, &pkt2) >= 0){
    if(pkt1.stream_index == aidx){
        pkt1.pts = av_rescale_q_rnd(pkt1.pts, ifmt1->streams[aidx]->time_base, ofmt->streams[aidx1]->time_base, (AV_ROUND_NEAR_INF | AV_ROUND_PASS_MINMAX));
        pkt1.dts = pkt1.pts;
        pkt1.stream_index = aidx1;
        av_interleaved_write_frame(ofmt, &pkt1);
        av_packet_unref(&pkt1);
    }
    if(pkt2.stream_index == vidx){
        pkt2.pts = av_rescale_q_rnd(pkt2.pts, ifmt2->streams[vidx]->time_base, ofmt->streams[vidx1]->time_base, (AV_ROUND_NEAR_INF | AV_ROUND_PASS_MINMAX));
        pkt2.dts = av_rescale_q_rnd(pkt2.dts, ifmt2->streams[vidx]->time_base, ofmt->streams[vidx1]->time_base, (AV_ROUND_NEAR_INF | AV_ROUND_PASS_MINMAX));
        pkt2.stream_index = vidx1;
        av_interleaved_write_frame(ofmt, &pkt2);
        av_packet_unref(&pkt2);        
    }
}

说些什么吧！

valine