ffmpeg.c

             */
            if(!strcmp(oc->oformat->name, "avi")) {
                if ( copy_tb<0 && av_q2d(ist->st->r_frame_rate) >= av_q2d(ist->st->avg_frame_rate)
                               && 0.5/av_q2d(ist->st->r_frame_rate) > av_q2d(ist->st->time_base)
                               && 0.5/av_q2d(ist->st->r_frame_rate) > av_q2d(icodec->time_base)
                               && av_q2d(ist->st->time_base) < 1.0/500 && av_q2d(icodec->time_base) < 1.0/500
                     || copy_tb==2){
                    codec->time_base.num = ist->st->r_frame_rate.den;
                    codec->time_base.den = 2*ist->st->r_frame_rate.num;
                    codec->ticks_per_frame = 2;
                } else if (   copy_tb<0 && av_q2d(icodec->time_base)*icodec->ticks_per_frame > 2*av_q2d(ist->st->time_base)
                                 && av_q2d(ist->st->time_base) < 1.0/500
                    || copy_tb==0){
                    codec->time_base = icodec->time_base;
                    codec->time_base.num *= icodec->ticks_per_frame;
                    codec->time_base.den *= 2;
                    codec->ticks_per_frame = 2;
                }
            } else if(!(oc->oformat->flags & AVFMT_VARIABLE_FPS)
                      && strcmp(oc->oformat->name, "mov") && strcmp(oc->oformat->name, "mp4") && strcmp(oc->oformat->name, "3gp")
                      && strcmp(oc->oformat->name, "3g2") && strcmp(oc->oformat->name, "psp") && strcmp(oc->oformat->name, "ipod")
            ) {
                if(   copy_tb<0 && av_q2d(icodec->time_base)*icodec->ticks_per_frame > av_q2d(ist->st->time_base)
                                && av_q2d(ist->st->time_base) < 1.0/500
                   || copy_tb==0){
                    codec->time_base = icodec->time_base;
                    codec->time_base.num *= icodec->ticks_per_frame;
                }
            }

            if(ost->frame_rate.num)
                codec->time_base = av_inv_q(ost->frame_rate);

            av_reduce(&codec->time_base.num, &codec->time_base.den,
                        codec->time_base.num, codec->time_base.den, INT_MAX);

            switch (codec->codec_type) {
            case AVMEDIA_TYPE_AUDIO:
                if (audio_volume != 256) {
                    av_log(NULL, AV_LOG_FATAL, "-acodec copy and -vol are incompatible (frames are not decoded)\n");
                    exit_program(1);
                }
                codec->channel_layout     = icodec->channel_layout;
                codec->sample_rate        = icodec->sample_rate;
                codec->channels           = icodec->channels;
                codec->frame_size         = icodec->frame_size;
                codec->audio_service_type = icodec->audio_service_type;
                codec->block_align        = icodec->block_align;
                if((codec->block_align == 1 || codec->block_align == 1152) && codec->codec_id == AV_CODEC_ID_MP3)
                    codec->block_align= 0;
                if(codec->codec_id == AV_CODEC_ID_AC3)
                    codec->block_align= 0;
                break;
            case AVMEDIA_TYPE_VIDEO:
                codec->pix_fmt            = icodec->pix_fmt;
                codec->width              = icodec->width;
                codec->height             = icodec->height;
                codec->has_b_frames       = icodec->has_b_frames;
                if (!codec->sample_aspect_ratio.num) {
                    codec->sample_aspect_ratio   =
                    ost->st->sample_aspect_ratio =
                        ist->st->sample_aspect_ratio.num ? ist->st->sample_aspect_ratio :
                        ist->st->codec->sample_aspect_ratio.num ?
                        ist->st->codec->sample_aspect_ratio : (AVRational){0, 1};
                }
                ost->st->avg_frame_rate = ist->st->avg_frame_rate;
                break;
            case AVMEDIA_TYPE_SUBTITLE:
                codec->width  = icodec->width;
                codec->height = icodec->height;
                break;
            case AVMEDIA_TYPE_DATA:
            case AVMEDIA_TYPE_ATTACHMENT:
                break;
            default:
                abort();
            }
        } else {
            if (!ost->enc)
                ost->enc = avcodec_find_encoder(codec->codec_id);
            if (!ost->enc) {
                /* should only happen when a default codec is not present. */
                snprintf(error, sizeof(error), "Encoder (codec %s) not found for output stream #%d:%d",
                         avcodec_get_name(ost->st->codec->codec_id), ost->file_index, ost->index);
                ret = AVERROR(EINVAL);
                goto dump_format;
            }

            if (ist)
                ist->decoding_needed = 1;
            ost->encoding_needed = 1;

            if (!ost->filter &&
                (codec->codec_type == AVMEDIA_TYPE_VIDEO ||
                 codec->codec_type == AVMEDIA_TYPE_AUDIO)) {
                    FilterGraph *fg;
                    fg = init_simple_filtergraph(ist, ost);
                    if (configure_filtergraph(fg)) {
                        av_log(NULL, AV_LOG_FATAL, "Error opening filters!\n");
                        exit(1);
                    }
            }

            if (codec->codec_type == AVMEDIA_TYPE_VIDEO) {
                if (ost->filter && !ost->frame_rate.num)
                    ost->frame_rate = av_buffersink_get_frame_rate(ost->filter->filter);
                if (ist && !ost->frame_rate.num)
                    ost->frame_rate = ist->st->r_frame_rate.num ? ist->st->r_frame_rate : (AVRational){25, 1};
//                    ost->frame_rate = ist->st->avg_frame_rate.num ? ist->st->avg_frame_rate : (AVRational){25, 1};
                if (ost->enc && ost->enc->supported_framerates && !ost->force_fps) {
                    int idx = av_find_nearest_q_idx(ost->frame_rate, ost->enc->supported_framerates);
                    ost->frame_rate = ost->enc->supported_framerates[idx];
                }
            }

            switch (codec->codec_type) {
            case AVMEDIA_TYPE_AUDIO:
                codec->sample_fmt     = ost->filter->filter->inputs[0]->format;
                codec->sample_rate    = ost->filter->filter->inputs[0]->sample_rate;
                codec->channel_layout = ost->filter->filter->inputs[0]->channel_layout;
                codec->channels       = av_get_channel_layout_nb_channels(codec->channel_layout);
                codec->time_base      = (AVRational){ 1, codec->sample_rate };
                break;
            case AVMEDIA_TYPE_VIDEO:
                codec->time_base = av_inv_q(ost->frame_rate);
                if (ost->filter && !(codec->time_base.num && codec->time_base.den))
                    codec->time_base = ost->filter->filter->inputs[0]->time_base;
                if (   av_q2d(codec->time_base) < 0.001 && video_sync_method != VSYNC_PASSTHROUGH
                   && (video_sync_method == VSYNC_CFR || (video_sync_method == VSYNC_AUTO && !(oc->oformat->flags & AVFMT_VARIABLE_FPS)))){
                    av_log(oc, AV_LOG_WARNING, "Frame rate very high for a muxer not efficiently supporting it.\n"
                                               "Please consider specifying a lower framerate, a different muxer or -vsync 2\n");
                }
                for (j = 0; j < ost->forced_kf_count; j++)
                    ost->forced_kf_pts[j] = av_rescale_q(ost->forced_kf_pts[j],
                                                         AV_TIME_BASE_Q,
                                                         codec->time_base);

                codec->width  = ost->filter->filter->inputs[0]->w;
                codec->height = ost->filter->filter->inputs[0]->h;
                codec->sample_aspect_ratio = ost->st->sample_aspect_ratio =
                    ost->frame_aspect_ratio ? // overridden by the -aspect cli option
                    av_d2q(ost->frame_aspect_ratio * codec->height/codec->width, 255) :
                    ost->filter->filter->inputs[0]->sample_aspect_ratio;
                codec->pix_fmt = ost->filter->filter->inputs[0]->format;

                if (!icodec ||
                    codec->width   != icodec->width  ||
                    codec->height  != icodec->height ||
                    codec->pix_fmt != icodec->pix_fmt) {
                    codec->bits_per_raw_sample = frame_bits_per_raw_sample;
                }

                if (ost->forced_keyframes)
                    parse_forced_key_frames(ost->forced_keyframes, ost,
                                            ost->st->codec);
                break;
            case AVMEDIA_TYPE_SUBTITLE:
                codec->time_base = (AVRational){1, 1000};
                break;
            default:
                abort();
                break;
            }
            /* two pass mode */
            if (codec->flags & (CODEC_FLAG_PASS1 | CODEC_FLAG_PASS2)) {
                char logfilename[1024];
                FILE *f;

                snprintf(logfilename, sizeof(logfilename), "%s-%d.log",
                         pass_logfilename_prefix ? pass_logfilename_prefix : DEFAULT_PASS_LOGFILENAME_PREFIX,
                         i);
                if (!strcmp(ost->enc->name, "libx264")) {
                    av_dict_set(&ost->opts, "stats", logfilename, AV_DICT_DONT_OVERWRITE);
                } else {
                    if (codec->flags & CODEC_FLAG_PASS2) {
                        char  *logbuffer;
                        size_t logbuffer_size;
                        if (cmdutils_read_file(logfilename, &logbuffer, &logbuffer_size) < 0) {
                            av_log(NULL, AV_LOG_FATAL, "Error reading log file '%s' for pass-2 encoding\n",
                                   logfilename);
                            exit_program(1);
                        }
                        codec->stats_in = logbuffer;
                    }
                    if (codec->flags & CODEC_FLAG_PASS1) {
                        f = fopen(logfilename, "wb");
                        if (!f) {
                            av_log(NULL, AV_LOG_FATAL, "Cannot write log file '%s' for pass-1 encoding: %s\n",
                                logfilename, strerror(errno));
                            exit_program(1);
                        }
                        ost->logfile = f;
                    }
                }
            }
        }
    }

    /* open each encoder */
    for (i = 0; i < nb_output_streams; i++) {
        ost = output_streams[i];
        if (ost->encoding_needed) {
            AVCodec      *codec = ost->enc;
            AVCodecContext *dec = NULL;

            if ((ist = get_input_stream(ost)))
                dec = ist->st->codec;
            if (dec && dec->subtitle_header) {
                /* ASS code assumes this buffer is null terminated so add extra byte. */
                ost->st->codec->subtitle_header = av_mallocz(dec->subtitle_header_size + 1);
                if (!ost->st->codec->subtitle_header) {
                    ret = AVERROR(ENOMEM);
                    goto dump_format;
                }
                memcpy(ost->st->codec->subtitle_header, dec->subtitle_header, dec->subtitle_header_size);
                ost->st->codec->subtitle_header_size = dec->subtitle_header_size;
            }
            if (!av_dict_get(ost->opts, "threads", NULL, 0))
                av_dict_set(&ost->opts, "threads", "auto", 0);
            if (avcodec_open2(ost->st->codec, codec, &ost->opts) < 0) {
                snprintf(error, sizeof(error), "Error while opening encoder for output stream #%d:%d - maybe incorrect parameters such as bit_rate, rate, width or height",
                        ost->file_index, ost->index);
                ret = AVERROR(EINVAL);
                goto dump_format;
            }
            if (ost->enc->type == AVMEDIA_TYPE_AUDIO &&
                !(ost->enc->capabilities & CODEC_CAP_VARIABLE_FRAME_SIZE))
                av_buffersink_set_frame_size(ost->filter->filter,
                                             ost->st->codec->frame_size);
            assert_codec_experimental(ost->st->codec, 1);
            assert_avoptions(ost->opts);
            if (ost->st->codec->bit_rate && ost->st->codec->bit_rate < 1000)
                av_log(NULL, AV_LOG_WARNING, "The bitrate parameter is set too low."
                                             " It takes bits/s as argument, not kbits/s\n");
            extra_size += ost->st->codec->extradata_size;

            if (ost->st->codec->me_threshold)
                input_streams[ost->source_index]->st->codec->debug |= FF_DEBUG_MV;
        }
    }

    /* init input streams */
    for (i = 0; i < nb_input_streams; i++)
        if ((ret = init_input_stream(i, error, sizeof(error))) < 0)
            goto dump_format;

    /* discard unused programs */
    for (i = 0; i < nb_input_files; i++) {
        InputFile *ifile = input_files[i];
        for (j = 0; j < ifile->ctx->nb_programs; j++) {
            AVProgram *p = ifile->ctx->programs[j];
            int discard  = AVDISCARD_ALL;

            for (k = 0; k < p->nb_stream_indexes; k++)
                if (!input_streams[ifile->ist_index + p->stream_index[k]]->discard) {
                    discard = AVDISCARD_DEFAULT;
                    break;
                }
            p->discard = discard;
        }
    }

    /* open files and write file headers */
    for (i = 0; i < nb_output_files; i++) {
        oc = output_files[i]->ctx;
        oc->interrupt_callback = int_cb;
        if ((ret = avformat_write_header(oc, &output_files[i]->opts)) < 0) {
            char errbuf[128];
            const char *errbuf_ptr = errbuf;
            if (av_strerror(ret, errbuf, sizeof(errbuf)) < 0)
                errbuf_ptr = strerror(AVUNERROR(ret));
            snprintf(error, sizeof(error), "Could not write header for output file #%d (incorrect codec parameters ?): %s", i, errbuf_ptr);
            ret = AVERROR(EINVAL);
            goto dump_format;
        }
//         assert_avoptions(output_files[i]->opts);
        if (strcmp(oc->oformat->name, "rtp")) {
            want_sdp = 0;
        }
    }

 dump_format:
    /* dump the file output parameters - cannot be done before in case
       of stream copy */
    for (i = 0; i < nb_output_files; i++) {
        av_dump_format(output_files[i]->ctx, i, output_files[i]->ctx->filename, 1);
    }

    /* dump the stream mapping */
    av_log(NULL, AV_LOG_INFO, "Stream mapping:\n");
    for (i = 0; i < nb_input_streams; i++) {
        ist = input_streams[i];

        for (j = 0; j < ist->nb_filters; j++) {
            if (ist->filters[j]->graph->graph_desc) {
                av_log(NULL, AV_LOG_INFO, "  Stream #%d:%d (%s) -> %s",
                       ist->file_index, ist->st->index, ist->dec ? ist->dec->name : "?",
                       ist->filters[j]->name);
                if (nb_filtergraphs > 1)
                    av_log(NULL, AV_LOG_INFO, " (graph %d)", ist->filters[j]->graph->index);
                av_log(NULL, AV_LOG_INFO, "\n");
            }
        }
    }

    for (i = 0; i < nb_output_streams; i++) {
        ost = output_streams[i];

        if (ost->attachment_filename) {
            /* an attached file */
            av_log(NULL, AV_LOG_INFO, "  File %s -> Stream #%d:%d\n",
                   ost->attachment_filename, ost->file_index, ost->index);
            continue;
        }

        if (ost->filter && ost->filter->graph->graph_desc) {
            /* output from a complex graph */
            av_log(NULL, AV_LOG_INFO, "  %s", ost->filter->name);
            if (nb_filtergraphs > 1)
                av_log(NULL, AV_LOG_INFO, " (graph %d)", ost->filter->graph->index);

            av_log(NULL, AV_LOG_INFO, " -> Stream #%d:%d (%s)\n", ost->file_index,
                   ost->index, ost->enc ? ost->enc->name : "?");
            continue;
        }

        av_log(NULL, AV_LOG_INFO, "  Stream #%d:%d -> #%d:%d",
               input_streams[ost->source_index]->file_index,
               input_streams[ost->source_index]->st->index,
               ost->file_index,
               ost->index);
        if (ost->sync_ist != input_streams[ost->source_index])
            av_log(NULL, AV_LOG_INFO, " [sync #%d:%d]",
                   ost->sync_ist->file_index,
                   ost->sync_ist->st->index);
        if (ost->stream_copy)
            av_log(NULL, AV_LOG_INFO, " (copy)");
        else
            av_log(NULL, AV_LOG_INFO, " (%s -> %s)", input_streams[ost->source_index]->dec ?
                   input_streams[ost->source_index]->dec->name : "?",
                   ost->enc ? ost->enc->name : "?");
        av_log(NULL, AV_LOG_INFO, "\n");
    }

    if (ret) {
        av_log(NULL, AV_LOG_ERROR, "%s\n", error);
        return ret;
    }

    if (want_sdp) {
        print_sdp();
    }

    return 0;
}

/**
 * @return 1 if there are still streams where more output is wanted,
 *         0 otherwise
 */
static int need_output(void)
{
    int i;

    for (i = 0; i < nb_output_streams; i++) {
        OutputStream *ost    = output_streams[i];
        OutputFile *of       = output_files[ost->file_index];
        AVFormatContext *os  = output_files[ost->file_index]->ctx;

        if (ost->is_past_recording_time ||
            (os->pb && avio_tell(os->pb) >= of->limit_filesize))
            continue;
        if (ost->frame_number >= ost->max_frames) {
            int j;
            for (j = 0; j < of->ctx->nb_streams; j++)
                output_streams[of->ost_index + j]->is_past_recording_time = 1;
            continue;
        }

        return 1;
    }

    return 0;
}

static int input_acceptable(InputStream *ist)
{
    av_assert1(!ist->discard);
    return !input_files[ist->file_index]->eagain &&
           !input_files[ist->file_index]->eof_reached;
}

static int find_graph_input(FilterGraph *graph)
{
    int i, nb_req_max = 0, file_index = -1;

    for (i = 0; i < graph->nb_inputs; i++) {
        int nb_req = av_buffersrc_get_nb_failed_requests(graph->inputs[i]->filter);
        if (nb_req > nb_req_max) {
            InputStream *ist = graph->inputs[i]->ist;
            if (input_acceptable(ist)) {
                nb_req_max = nb_req;
                file_index = ist->file_index;
            }
        }
    }

    return file_index;
}

/**
 * Select the input file to read from.
 *
 * @return  >=0 index of the input file to use;
 *          -1  if no file is acceptable;
 *          -2  to read from filters without reading from a file
 */
static int select_input_file(void)
{
    int i, ret, nb_active_out = nb_output_streams, ost_index = -1;
    int64_t opts_min;
    OutputStream *ost;
    AVFilterBufferRef *dummy;

    for (i = 0; i < nb_output_streams; i++)
        nb_active_out -= output_streams[i]->unavailable =
            output_streams[i]->is_past_recording_time;
    while (nb_active_out) {
        opts_min = INT64_MAX;
        ost_index = -1;
        for (i = 0; i < nb_output_streams; i++) {
            OutputStream *ost = output_streams[i];
            int64_t opts = av_rescale_q(ost->st->cur_dts, ost->st->time_base,
                                        AV_TIME_BASE_Q);
            if (!ost->unavailable && opts < opts_min) {
                opts_min  = opts;
                ost_index = i;
            }
        }
        if (ost_index < 0)
            return -1;

        ost = output_streams[ost_index];
        if (ost->source_index >= 0) {
            /* ost is directly connected to an input */
            InputStream *ist = input_streams[ost->source_index];
            if (input_acceptable(ist))
                return ist->file_index;
        } else {
            /* ost is connected to a complex filtergraph */
            av_assert1(ost->filter);
            ret = av_buffersink_get_buffer_ref(ost->filter->filter, &dummy,
                                               AV_BUFFERSINK_FLAG_PEEK);
            if (ret >= 0)
                return -2;
            ret = find_graph_input(ost->filter->graph);
            if (ret >= 0)
                return ret;
        }
        ost->unavailable = 1;
        nb_active_out--;
    }
    return -1;
}

static int check_keyboard_interaction(int64_t cur_time)
{
    int i, ret, key;
    static int64_t last_time;
    if (received_nb_signals)
        return AVERROR_EXIT;
    /* read_key() returns 0 on EOF */
    if(cur_time - last_time >= 100000 && !run_as_daemon){
        key =  read_key();
        last_time = cur_time;
    }else
        key = -1;
    if (key == 'q')
        return AVERROR_EXIT;
    if (key == '+') av_log_set_level(av_log_get_level()+10);
    if (key == '-') av_log_set_level(av_log_get_level()-10);
    if (key == 's') qp_hist     ^= 1;
    if (key == 'h'){
        if (do_hex_dump){
            do_hex_dump = do_pkt_dump = 0;
        } else if(do_pkt_dump){
            do_hex_dump = 1;
        } else
            do_pkt_dump = 1;
        av_log_set_level(AV_LOG_DEBUG);
    }
    if (key == 'c' || key == 'C'){
        char buf[4096], target[64], command[256], arg[256] = {0};
        double time;
        int k, n = 0;
        fprintf(stderr, "\nEnter command: <target> <time> <command>[ <argument>]\n");
        i = 0;
        while ((k = read_key()) != '\n' && k != '\r' && i < sizeof(buf)-1)
            if (k > 0)
                buf[i++] = k;
        buf[i] = 0;
        if (k > 0 &&
            (n = sscanf(buf, "%63[^ ] %lf %255[^ ] %255[^\n]", target, &time, command, arg)) >= 3) {
            av_log(NULL, AV_LOG_DEBUG, "Processing command target:%s time:%f command:%s arg:%s",
                   target, time, command, arg);
            for (i = 0; i < nb_filtergraphs; i++) {
                FilterGraph *fg = filtergraphs[i];
                if (fg->graph) {
                    if (time < 0) {
                        ret = avfilter_graph_send_command(fg->graph, target, command, arg, buf, sizeof(buf),
                                                          key == 'c' ? AVFILTER_CMD_FLAG_ONE : 0);
                        fprintf(stderr, "Command reply for stream %d: ret:%d res:%s\n", i, ret, buf);
                    } else {
                        ret = avfilter_graph_queue_command(fg->graph, target, command, arg, 0, time);
                    }
                }
            }
        } else {
            av_log(NULL, AV_LOG_ERROR,
                   "Parse error, at least 3 arguments were expected, "
                   "only %d given in string '%s'\n", n, buf);
        }
    }
    if (key == 'd' || key == 'D'){
        int debug=0;
        if(key == 'D') {
            debug = input_streams[0]->st->codec->debug<<1;
            if(!debug) debug = 1;
            while(debug & (FF_DEBUG_DCT_COEFF|FF_DEBUG_VIS_QP|FF_DEBUG_VIS_MB_TYPE)) //unsupported, would just crash
                debug += debug;
        }else
            if(scanf("%d", &debug)!=1)
                fprintf(stderr,"error parsing debug value\n");
        for(i=0;i<nb_input_streams;i++) {
            input_streams[i]->st->codec->debug = debug;
        }
        for(i=0;i<nb_output_streams;i++) {
            OutputStream *ost = output_streams[i];
            ost->st->codec->debug = debug;
        }
        if(debug) av_log_set_level(AV_LOG_DEBUG);
        fprintf(stderr,"debug=%d\n", debug);
    }
    if (key == '?'){
        fprintf(stderr, "key    function\n"
                        "?      show this help\n"
                        "+      increase verbosity\n"
                        "-      decrease verbosity\n"
                        "c      Send command to filtergraph\n"
                        "D      cycle through available debug modes\n"
                        "h      dump packets/hex press to cycle through the 3 states\n"
                        "q      quit\n"
                        "s      Show QP histogram\n"
        );
    }
    return 0;
}

#if HAVE_PTHREADS
static void *input_thread(void *arg)
{
    InputFile *f = arg;
    int ret = 0;

    while (!transcoding_finished && ret >= 0) {
        AVPacket pkt;
        ret = av_read_frame(f->ctx, &pkt);

        if (ret == AVERROR(EAGAIN)) {
            av_usleep(10000);
            ret = 0;
            continue;
        } else if (ret < 0)
            break;

        pthread_mutex_lock(&f->fifo_lock);
        while (!av_fifo_space(f->fifo))
            pthread_cond_wait(&f->fifo_cond, &f->fifo_lock);

        av_dup_packet(&pkt);
        av_fifo_generic_write(f->fifo, &pkt, sizeof(pkt), NULL);

        pthread_mutex_unlock(&f->fifo_lock);
    }

    f->finished = 1;
    return NULL;
}

static void free_input_threads(void)
{
    int i;

    if (nb_input_files == 1)
        return;

    transcoding_finished = 1;

    for (i = 0; i < nb_input_files; i++) {
        InputFile *f = input_files[i];
        AVPacket pkt;

        if (!f->fifo || f->joined)
            continue;

        pthread_mutex_lock(&f->fifo_lock);
        while (av_fifo_size(f->fifo)) {
            av_fifo_generic_read(f->fifo, &pkt, sizeof(pkt), NULL);
            av_free_packet(&pkt);
        }
        pthread_cond_signal(&f->fifo_cond);
        pthread_mutex_unlock(&f->fifo_lock);

        pthread_join(f->thread, NULL);
        f->joined = 1;

        while (av_fifo_size(f->fifo)) {
            av_fifo_generic_read(f->fifo, &pkt, sizeof(pkt), NULL);
            av_free_packet(&pkt);
        }
        av_fifo_free(f->fifo);
    }
}

static int init_input_threads(void)
{
    int i, ret;

    if (nb_input_files == 1)
        return 0;

    for (i = 0; i < nb_input_files; i++) {
        InputFile *f = input_files[i];

        if (!(f->fifo = av_fifo_alloc(8*sizeof(AVPacket))))
            return AVERROR(ENOMEM);

        pthread_mutex_init(&f->fifo_lock, NULL);
        pthread_cond_init (&f->fifo_cond, NULL);

        if ((ret = pthread_create(&f->thread, NULL, input_thread, f)))
            return AVERROR(ret);
    }
    return 0;
}

static int get_input_packet_mt(InputFile *f, AVPacket *pkt)
{
    int ret = 0;

    pthread_mutex_lock(&f->fifo_lock);

    if (av_fifo_size(f->fifo)) {
        av_fifo_generic_read(f->fifo, pkt, sizeof(*pkt), NULL);
        pthread_cond_signal(&f->fifo_cond);
    } else {
        if (f->finished)
            ret = AVERROR_EOF;
        else
            ret = AVERROR(EAGAIN);
    }

    pthread_mutex_unlock(&f->fifo_lock);

    return ret;
}
#endif

static int get_input_packet(InputFile *f, AVPacket *pkt)
{
#if HAVE_PTHREADS
    if (nb_input_files > 1)
        return get_input_packet_mt(f, pkt);
#endif
    return av_read_frame(f->ctx, pkt);
}

static int got_eagain(void)
{
    int i;
    for (i = 0; i < nb_input_files; i++)
        if (input_files[i]->eagain)
            return 1;
    return 0;
}

static void reset_eagain(void)
{
    int i;
    for (i = 0; i < nb_input_files; i++)
        input_files[i]->eagain = 0;
}

/*
 * The following code is the main loop of the file converter
 */
static int transcode(void)
{
    int ret, i;
    AVFormatContext *is, *os;
    OutputStream *ost;
    InputStream *ist;
    int64_t timer_start;

    ret = transcode_init();
    if (ret < 0)
        goto fail;

    if (stdin_interaction) {
        av_log(NULL, AV_LOG_INFO, "Press [q] to stop, [?] for help\n");
    }

    timer_start = av_gettime();

#if HAVE_PTHREADS
    if ((ret = init_input_threads()) < 0)
        goto fail;
#endif

    while (!received_sigterm) {
        InputFile *ifile;
        AVPacket pkt;
        int file_index;
        int64_t cur_time= av_gettime();

        /* if 'q' pressed, exits */
        if (stdin_interaction)
            if (check_keyboard_interaction(cur_time) < 0)
                break;

        /* check if there's any stream where output is still needed */
        if (!need_output()) {
            av_log(NULL, AV_LOG_VERBOSE, "No more output streams to write to, finishing.\n");
            break;
        }

        /* select the stream that we must read now */
        file_index = select_input_file();
        /* if none, if is finished */
        if (file_index == -2) {
            poll_filters() ;
            continue;
        }
        if (file_index < 0) {
            if (got_eagain()) {
                reset_eagain();
                av_usleep(10000);
                continue;
            }
            av_log(NULL, AV_LOG_VERBOSE, "No more inputs to read from, finishing.\n");
            break;
        }
        ifile = input_files[file_index];

        is  = ifile->ctx;
        ret = get_input_packet(ifile, &pkt);

        if (ret == AVERROR(EAGAIN)) {
            ifile->eagain = 1;
            continue;
        }
        if (ret < 0) {
            if (ret != AVERROR_EOF) {
                print_error(is->filename, ret);
                if (exit_on_error)
                    exit_program(1);
            }
            ifile->eof_reached = 1;

            for (i = 0; i < ifile->nb_streams; i++) {
                ist = input_streams[ifile->ist_index + i];
                if (ist->decoding_needed)
                    output_packet(ist, NULL);
                poll_filters();
            }

            if (opt_shortest)
                break;
            else
                continue;
        }

        reset_eagain();

        if (do_pkt_dump) {
            av_pkt_dump_log2(NULL, AV_LOG_DEBUG, &pkt, do_hex_dump,
                             is->streams[pkt.stream_index]);
        }
        /* the following test is needed in case new streams appear
           dynamically in stream : we ignore them */
        if (pkt.stream_index >= ifile->nb_streams) {
            report_new_stream(file_index, &pkt);
            goto discard_packet;
        }

        ist = input_streams[ifile->ist_index + pkt.stream_index];
        if (ist->discard)
            goto discard_packet;

        if(!ist->wrap_correction_done && input_files[file_index]->ctx->start_time != AV_NOPTS_VALUE && ist->st->pts_wrap_bits < 64){
            uint64_t stime = av_rescale_q(input_files[file_index]->ctx->start_time, AV_TIME_BASE_Q, ist->st->time_base);
            uint64_t stime2= stime + (1LL<<ist->st->pts_wrap_bits);
            ist->wrap_correction_done = 1;
            if(pkt.dts != AV_NOPTS_VALUE && pkt.dts > stime && pkt.dts - stime > stime2 - pkt.dts) {
                pkt.dts -= 1LL<<ist->st->pts_wrap_bits;
                ist->wrap_correction_done = 0;
            }
            if(pkt.pts != AV_NOPTS_VALUE && pkt.pts > stime && pkt.pts - stime > stime2 - pkt.pts) {
                pkt.pts -= 1LL<<ist->st->pts_wrap_bits;
                ist->wrap_correction_done = 0;
            }
        }

        if (pkt.dts != AV_NOPTS_VALUE)
            pkt.dts += av_rescale_q(ifile->ts_offset, AV_TIME_BASE_Q, ist->st->time_base);
        if (pkt.pts != AV_NOPTS_VALUE)
            pkt.pts += av_rescale_q(ifile->ts_offset, AV_TIME_BASE_Q, ist->st->time_base);

        if (pkt.pts != AV_NOPTS_VALUE)
            pkt.pts *= ist->ts_scale;
        if (pkt.dts != AV_NOPTS_VALUE)
            pkt.dts *= ist->ts_scale;

        if (debug_ts) {
            av_log(NULL, AV_LOG_INFO, "demuxer -> ist_index:%d type:%s "
                    "next_dts:%s next_dts_time:%s next_pts:%s next_pts_time:%s  pkt_pts:%s pkt_pts_time:%s pkt_dts:%s pkt_dts_time:%s off:%"PRId64"\n",
                    ifile->ist_index + pkt.stream_index, av_get_media_type_string(ist->st->codec->codec_type),
                    av_ts2str(ist->next_dts), av_ts2timestr(ist->next_dts, &AV_TIME_BASE_Q),
                    av_ts2str(ist->next_pts), av_ts2timestr(ist->next_pts, &AV_TIME_BASE_Q),
                    av_ts2str(pkt.pts), av_ts2timestr(pkt.pts, &ist->st->time_base),
                    av_ts2str(pkt.dts), av_ts2timestr(pkt.dts, &ist->st->time_base),
                    input_files[ist->file_index]->ts_offset);
        }

        if (pkt.dts != AV_NOPTS_VALUE && ist->next_dts != AV_NOPTS_VALUE && !copy_ts) {
            int64_t pkt_dts = av_rescale_q(pkt.dts, ist->st->time_base, AV_TIME_BASE_Q);
            int64_t delta   = pkt_dts - ist->next_dts;
            if (is->iformat->flags & AVFMT_TS_DISCONT) {
            if(delta < -1LL*dts_delta_threshold*AV_TIME_BASE ||
                (delta > 1LL*dts_delta_threshold*AV_TIME_BASE &&
                 ist->st->codec->codec_type != AVMEDIA_TYPE_SUBTITLE) ||
                pkt_dts+1<ist->pts){
                ifile->ts_offset -= delta;
                av_log(NULL, AV_LOG_DEBUG,
                       "timestamp discontinuity %"PRId64", new offset= %"PRId64"\n",
                       delta, ifile->ts_offset);
                pkt.dts-= av_rescale_q(delta, AV_TIME_BASE_Q, ist->st->time_base);
                if (pkt.pts != AV_NOPTS_VALUE)
                    pkt.pts-= av_rescale_q(delta, AV_TIME_BASE_Q, ist->st->time_base);
            }
            } else {
                if ( delta < -1LL*dts_error_threshold*AV_TIME_BASE ||
                    (delta > 1LL*dts_error_threshold*AV_TIME_BASE && ist->st->codec->codec_type != AVMEDIA_TYPE_SUBTITLE) ||
                     pkt_dts+1<ist->pts){
                    av_log(NULL, AV_LOG_WARNING, "DTS %"PRId64", next:%"PRId64" st:%d invalid dropping\n", pkt.dts, ist->next_dts, pkt.stream_index);
                    pkt.dts = AV_NOPTS_VALUE;
                }
                if (pkt.pts != AV_NOPTS_VALUE){
                    int64_t pkt_pts = av_rescale_q(pkt.pts, ist->st->time_base, AV_TIME_BASE_Q);
                    delta   = pkt_pts - ist->next_dts;
                    if ( delta < -1LL*dts_error_threshold*AV_TIME_BASE ||
                        (delta > 1LL*dts_error_threshold*AV_TIME_BASE && ist->st->codec->codec_type != AVMEDIA_TYPE_SUBTITLE) ||
                        pkt_pts+1<ist->pts) {
                        av_log(NULL, AV_LOG_WARNING, "PTS %"PRId64", next:%"PRId64" invalid dropping st:%d\n", pkt.pts, ist->next_dts, pkt.stream_index);
                        pkt.pts = AV_NOPTS_VALUE;
                    }
                }
            }
        }

        sub2video_heartbeat(ist, pkt.pts);

        if ((ret = output_packet(ist, &pkt)) < 0 ||
            ((ret = poll_filters()) < 0 && ret != AVERROR_EOF)) {
            char buf[128];
            av_strerror(ret, buf, sizeof(buf));
            av_log(NULL, AV_LOG_ERROR, "Error while decoding stream #%d:%d: %s\n",
                   ist->file_index, ist->st->index, buf);
            if (exit_on_error)
                exit_program(1);
            av_free_packet(&pkt);
            continue;
        }

    discard_packet:
        av_free_packet(&pkt);

        /* dump report by using the output first video and audio streams */
        print_report(0, timer_start, cur_time);
    }
#if HAVE_PTHREADS
    free_input_threads();
#endif

    /* at the end of stream, we must flush the decoder buffers */
    for (i = 0; i < nb_input_streams; i++) {
        ist = input_streams[i];
        if (!input_files[ist->file_index]->eof_reached && ist->decoding_needed) {
            output_packet(ist, NULL);
        }
    }
    poll_filters();
    flush_encoders();

    term_exit();

    /* write the trailer if needed and close file */
    for (i = 0; i < nb_output_files; i++) {
        os = output_files[i]->ctx;
        av_write_trailer(os);
    }

    /* dump report by using the first video and audio streams */
    print_report(1, timer_start, av_gettime());

    /* close each encoder */
    for (i = 0; i < nb_output_streams; i++) {
        ost = output_streams[i];
        if (ost->encoding_needed) {
            av_freep(&ost->st->codec->stats_in);
            avcodec_close(ost->st->codec);
        }
    }

    /* close each decoder */
    for (i = 0; i < nb_input_streams; i++) {
        ist = input_streams[i];
        if (ist->decoding_needed) {
            avcodec_close(ist->st->codec);
        }
    }

    /* finished ! */
    ret = 0;

 fail:
#if HAVE_PTHREADS
    free_input_threads();
#endif

    if (output_streams) {
        for (i = 0; i < nb_output_streams; i++) {
            ost = output_streams[i];
            if (ost) {
                if (ost->stream_copy)
                    av_freep(&ost->st->codec->extradata);
                if (ost->logfile) {
                    fclose(ost->logfile);
                    ost->logfile = NULL;
                }
                av_freep(&ost->st->codec->subtitle_header);
                av_free(ost->forced_kf_pts);
                av_dict_free(&ost->opts);
            }
        }
    }
    return ret;
}


static int64_t getutime(void)
{
#if HAVE_GETRUSAGE
    struct rusage rusage;

    getrusage(RUSAGE_SELF, &rusage);
    return (rusage.ru_utime.tv_sec * 1000000LL) + rusage.ru_utime.tv_usec;
#elif HAVE_GETPROCESSTIMES
    HANDLE proc;
    FILETIME c, e, k, u;
    proc = GetCurrentProcess();
    GetProcessTimes(proc, &c, &e, &k, &u);
    return ((int64_t) u.dwHighDateTime << 32 | u.dwLowDateTime) / 10;
#else
    return av_gettime();
#endif
}

static int64_t getmaxrss(void)
{
#if HAVE_GETRUSAGE && HAVE_STRUCT_RUSAGE_RU_MAXRSS
    struct rusage rusage;
    getrusage(RUSAGE_SELF, &rusage);
    return (int64_t)rusage.ru_maxrss * 1024;
#elif HAVE_GETPROCESSMEMORYINFO
    HANDLE proc;
    PROCESS_MEMORY_COUNTERS memcounters;
    proc = GetCurrentProcess();
    memcounters.cb = sizeof(memcounters);
    GetProcessMemoryInfo(proc, &memcounters, sizeof(memcounters));
    return memcounters.PeakPagefileUsage;
#else
    return 0;
#endif
}

static void log_callback_null(void *ptr, int level, const char *fmt, va_list vl)
{
}