#include <libavutil/timestamp.h>
#include <libavformat/avformat.h>

static void log_packet(const AVFormatContext *fmt_ctx, const AVPacket
*pkt, const char *tag)
{
    AVRational *time_base = &fmt_ctx->streams[pkt->stream_index]->time_base;

    printf("%s: pts:%s pts_time:%s dts:%s dts_time:%s duration:%s
duration_time:%s stream_index:%d\n",
           tag,
           av_ts2str(pkt->pts), av_ts2timestr(pkt->pts, time_base),
           av_ts2str(pkt->dts), av_ts2timestr(pkt->dts, time_base),
           av_ts2str(pkt->duration), av_ts2timestr(pkt->duration, time_base),
           pkt->stream_index);
}


int main(int argc, char **argv)
{
    AVOutputFormat *ofmt = NULL;
    AVFormatContext *ifmt_ctx = NULL, *ofmt_ctx = NULL;
    AVPacket pkt;
    const char *in_filename, *out_filename;
    int ret, i;
    int stream_index = 0;
    int *stream_mapping = NULL;
    int stream_mapping_size = 0;
    AVRational mux_timebase;
    int64_t start_time = 0; //(of->start_time == AV_NOPTS_VALUE) ? 0 :
of->start_time;
    int64_t ost_tb_start_time = 0; //av_rescale_q(start_time,
AV_TIME_BASE_Q, ost->mux_timebase);

    if (argc < 3) {
        printf("usage: %s input output\n"
               "API example program to remux a media file with
libavformat and libavcodec.\n"
               "The output format is guessed according to the file extension.\n"
               "\n", argv[0]);
        return 1;
    }

    in_filename  = argv[1];
    out_filename = argv[2];

    av_register_all();
    avcodec_register_all();
    avformat_network_init();

    if ((ret = avformat_open_input(&ifmt_ctx, in_filename, 0, 0)) < 0) {
        fprintf(stderr, "Could not open input file '%s'", in_filename);
        goto end;
    }

    if ((ret = avformat_find_stream_info(ifmt_ctx, 0)) < 0) {
        fprintf(stderr, "Failed to retrieve input stream information");
        goto end;
    }

    av_dump_format(ifmt_ctx, 0, in_filename, 0);

    avformat_alloc_output_context2(&ofmt_ctx, NULL, "rtp_mpegts", out_filename);
    if (!ofmt_ctx) {
        fprintf(stderr, "Could not create output context\n");
        ret = AVERROR_UNKNOWN;
        goto end;
    }

    stream_mapping_size = ifmt_ctx->nb_streams;
    stream_mapping = av_mallocz_array(stream_mapping_size,
sizeof(*stream_mapping));
    if (!stream_mapping) {
        ret = AVERROR(ENOMEM);
        goto end;
    }

    ofmt = ofmt_ctx->oformat;

    for (i = 0; i < ifmt_ctx->nb_streams; i++)
    {
        AVStream *out_stream;
        AVStream *in_stream = ifmt_ctx->streams[i];
        AVCodecParameters *in_codecpar = in_stream->codecpar;

        if (in_codecpar->codec_type != AVMEDIA_TYPE_AUDIO &&
            in_codecpar->codec_type != AVMEDIA_TYPE_VIDEO &&
            in_codecpar->codec_type != AVMEDIA_TYPE_SUBTITLE) {
            stream_mapping[i] = -1;
            continue;
        }

        stream_mapping[i] = stream_index++;


        out_stream = avformat_new_stream(ofmt_ctx, NULL);
        if (!out_stream) {
            fprintf(stderr, "Failed allocating output stream\n");
            ret = AVERROR_UNKNOWN;
            goto end;
        }

        //out_stream->codecpar->codec_tag = 0;
        if (0 == out_stream->codecpar->codec_tag)
        {
            unsigned int codec_tag_tmp;

            if (!out_stream->codecpar->codec_tag ||
                av_codec_get_id (ofmt->codec_tag,
in_codecpar->codec_tag) == in_codecpar->codec_id ||
                !av_codec_get_tag2(ofmt->codec_tag,
in_codecpar->codec_id, &codec_tag_tmp))
                out_stream->codecpar->codec_tag  = in_codecpar->codec_tag;
        }
        //ret = avcodec_parameters_to_context(ost->enc_ctx, ist->st->codecpar);

        ret = avcodec_parameters_copy(out_stream->codecpar, in_codecpar);
        if (ret < 0) {
            fprintf(stderr, "Failed to copy codec parameters\n");
            goto end;
        }
        //out_stream->codecpar->codec_tag = codec_tag;
        // copy timebase while removing common factors

        printf("bit_rate %lld sample_rate %d frame_size %d\n",
               in_codecpar->bit_rate, in_codecpar->sample_rate,
in_codecpar->frame_size);

        out_stream->avg_frame_rate = in_stream->avg_frame_rate;

        ret = avformat_transfer_internal_stream_timing_info(ofmt,

out_stream, in_stream,
                                                            AVFMT_TBCF_AUTO);
        if (ret < 0) {
            fprintf(stderr,
"avformat_transfer_internal_stream_timing_info failed\n");
            goto end;
        }

        if (out_stream->time_base.num <= 0 || out_stream->time_base.den <= 0)
            out_stream->time_base =
av_add_q(av_stream_get_codec_timebase(out_stream), (AVRational){0,
1});

        // copy estimated duration as a hint to the muxer
        if (out_stream->duration <= 0 && in_stream->duration > 0)
            out_stream->duration = av_rescale_q(in_stream->duration,
in_stream->time_base, out_stream->time_base);

        // copy disposition
        out_stream->disposition = in_stream->disposition;

        out_stream->sample_aspect_ratio = in_stream->sample_aspect_ratio;
        out_stream->avg_frame_rate = in_stream->avg_frame_rate;
        out_stream->r_frame_rate = in_stream->r_frame_rate;

        if ( in_codecpar->codec_type == AVMEDIA_TYPE_VIDEO)
        {

            mux_timebase = in_stream->time_base;
        }


        if (in_stream->nb_side_data) {
            for (i = 0; i < in_stream->nb_side_data; i++) {
                const AVPacketSideData *sd_src = &in_stream->side_data[i];
                uint8_t *dst_data;

                dst_data = av_stream_new_side_data(out_stream,
sd_src->type, sd_src->size);
                if (!dst_data)
                    return AVERROR(ENOMEM);
                memcpy(dst_data, sd_src->data, sd_src->size);
            }
        }
    }

    av_dump_format(ofmt_ctx, 0, out_filename, 1);

    start_time = ofmt_ctx->duration;
    ost_tb_start_time = av_rescale_q(ofmt_ctx->duration,
AV_TIME_BASE_Q, mux_timebase);

    if (!(ofmt->flags & AVFMT_NOFILE))
    {
        ret = avio_open(&ofmt_ctx->pb, out_filename, AVIO_FLAG_WRITE);
        if (ret < 0) {
            fprintf(stderr, "Could not open output file '%s'", out_filename);
            goto end;
        }
    }

    ret = avformat_write_header(ofmt_ctx, NULL);
    if (ret < 0) {
        fprintf(stderr, "Error occurred when opening output file\n");
        goto end;
    }

    while (1)
    {
        AVStream *in_stream, *out_stream;

        ret = av_read_frame(ifmt_ctx, &pkt);
        if (ret < 0)
            break;

        in_stream  = ifmt_ctx->streams[pkt.stream_index];
        if (pkt.stream_index >= stream_mapping_size ||
            stream_mapping[pkt.stream_index] < 0) {
            av_packet_unref(&pkt);
            continue;
        }

        pkt.stream_index = stream_mapping[pkt.stream_index];
        out_stream = ofmt_ctx->streams[pkt.stream_index];

        //log_packet(ifmt_ctx, &pkt, "in");


        //ofmt_ctx->bit_rate = ifmt_ctx->bit_rate;
        ofmt_ctx->duration = ifmt_ctx->duration;
        /* copy packet */
        //pkt.pts = av_rescale_q_rnd(pkt.pts, in_stream->time_base,
out_stream->time_base, AV_ROUND_NEAR_INF|AV_ROUND_PASS_MINMAX);
        //pkt.dts = av_rescale_q_rnd(pkt.dts, in_stream->time_base,
out_stream->time_base, AV_ROUND_NEAR_INF|AV_ROUND_PASS_MINMAX);

        if (pkt.pts != AV_NOPTS_VALUE)
            pkt.pts = av_rescale_q(pkt.pts,
in_stream->time_base,mux_timebase) - ost_tb_start_time;
        else
            pkt.pts = AV_NOPTS_VALUE;

        if (pkt.dts == AV_NOPTS_VALUE)
            pkt.dts = av_rescale_q(pkt.dts, AV_TIME_BASE_Q, mux_timebase);
        else
            pkt.dts = av_rescale_q(pkt.dts, in_stream->time_base, mux_timebase);
        pkt.dts -= ost_tb_start_time;

        pkt.duration = av_rescale_q(pkt.duration,
in_stream->time_base, mux_timebase);
        //pkt.duration = av_rescale_q(1,
av_inv_q(out_stream->avg_frame_rate), mux_timebase);
        pkt.pos = -1;
        //log_packet(ofmt_ctx, &pkt, "out");


        ret = av_interleaved_write_frame(ofmt_ctx, &pkt);
        if (ret < 0) {
            fprintf(stderr, "Error muxing packet\n");
            break;
        }
        av_packet_unref(&pkt);
    }

    av_write_trailer(ofmt_ctx);
end:

    avformat_close_input(&ifmt_ctx);

    /* close output */
    if (ofmt_ctx && !(ofmt->flags & AVFMT_NOFILE))
        avio_closep(&ofmt_ctx->pb);
    avformat_free_context(ofmt_ctx);

    av_freep(&stream_mapping);

    if (ret < 0 && ret != AVERROR_EOF) {
        fprintf(stderr, "Error occurred: %s\n", av_err2str(ret));
        return 1;
    }

    return 0;
}