avconv.c

        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 (f->rate_emu) {
        int i;
        for (i = 0; i < f->nb_streams; i++) {
            InputStream *ist = input_streams[f->ist_index + i];
            int64_t pts = av_rescale(ist->last_dts, 1000000, AV_TIME_BASE);
            int64_t now = av_gettime() - ist->start;
            if (pts > now)
                return AVERROR(EAGAIN);
        }
    }

#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;
}

/*
 * Read one packet from an input file and send it for
 * - decoding -> lavfi (audio/video)
 * - decoding -> encoding -> muxing (subtitles)
 * - muxing (streamcopy)
 *
 * Return
 * - 0 -- one packet was read and processed
 * - AVERROR(EAGAIN) -- no packets were available for selected file,
 *   this function should be called again
 * - AVERROR_EOF -- this function should not be called again
 */
static int process_input(void)
{
    InputFile *ifile;
    AVFormatContext *is;
    InputStream *ist;
    AVPacket pkt;
    int ret, i, j;

    /* select the stream that we must read now */
    ifile = select_input_file();
    /* if none, if is finished */
    if (!ifile) {
        if (got_eagain()) {
            reset_eagain();
            av_usleep(10000);
            return AVERROR(EAGAIN);
        }
        av_log(NULL, AV_LOG_VERBOSE, "No more inputs to read from.\n");
        return AVERROR_EOF;
    }

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

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

            /* mark all outputs that don't go through lavfi as finished */
            for (j = 0; j < nb_output_streams; j++) {
                OutputStream *ost = output_streams[j];

                if (ost->source_index == ifile->ist_index + i &&
                    (ost->stream_copy || ost->enc->type == AVMEDIA_TYPE_SUBTITLE))
                    ost->finished= 1;
            }
        }

        return AVERROR(EAGAIN);
    }

    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)
        goto discard_packet;

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

    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 (pkt.dts != AV_NOPTS_VALUE && ist->next_dts != AV_NOPTS_VALUE &&
        (is->iformat->flags & AVFMT_TS_DISCONT)) {
        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 ((FFABS(delta) > 1LL * dts_delta_threshold * AV_TIME_BASE || pkt_dts + 1 < ist->last_dts) && !copy_ts) {
            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);
        }
    }

    ret = output_packet(ist, &pkt);
    if (ret < 0) {
        av_log(NULL, AV_LOG_ERROR, "Error while decoding stream #%d:%d\n",
               ist->file_index, ist->st->index);
        if (exit_on_error)
            exit(1);
    }

discard_packet:
    av_free_packet(&pkt);

    return 0;
}

/*
 * The following code is the main loop of the file converter
 */
static int transcode(void)
{
    int ret, i, need_input = 1;
    AVFormatContext *os;
    OutputStream *ost;
    InputStream *ist;
    int64_t timer_start;

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

    av_log(NULL, AV_LOG_INFO, "Press ctrl-c to stop encoding\n");
    term_init();

    timer_start = av_gettime();

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

    while (!received_sigterm) {
        /* 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;
        }

        /* read and process one input packet if needed */
        if (need_input) {
            ret = process_input();
            if (ret == AVERROR_EOF)
                need_input = 0;
        }

        ret = poll_filters();
        if (ret < 0) {
            if (ret == AVERROR_EOF || ret == AVERROR(EAGAIN))
                continue;

            av_log(NULL, AV_LOG_ERROR, "Error while filtering.\n");
            break;
        }

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

    /* 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);
                av_dict_free(&ost->resample_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
}

int main(int argc, char **argv)
{
    int ret;
    int64_t ti;

    atexit(exit_program);

    av_log_set_flags(AV_LOG_SKIP_REPEATED);
    parse_loglevel(argc, argv, options);

    avcodec_register_all();
#if CONFIG_AVDEVICE
    avdevice_register_all();
#endif
    avfilter_register_all();
    av_register_all();
    avformat_network_init();

    show_banner();

    /* parse options and open all input/output files */
    ret = avconv_parse_options(argc, argv);
    if (ret < 0)
        exit(1);

    if (nb_output_files <= 0 && nb_input_files == 0) {
        show_usage();
        av_log(NULL, AV_LOG_WARNING, "Use -h to get full help or, even better, run 'man %s'\n", program_name);
        exit(1);
    }

    /* file converter / grab */
    if (nb_output_files <= 0) {
        fprintf(stderr, "At least one output file must be specified\n");
        exit(1);
    }

    ti = getutime();
    if (transcode() < 0)
        exit(1);
    ti = getutime() - ti;
    if (do_benchmark) {
        int maxrss = getmaxrss() / 1024;
        printf("bench: utime=%0.3fs maxrss=%ikB\n", ti / 1000000.0, maxrss);
    }

    exit(0);
    return 0;
}