Function hb_vfr_init

libhb/vfr.c:367–462

}

static int hb_vfr_init(hb_filter_object_t *filter, hb_filter_init_t *init)
{
    filter->private_data    = calloc(1, sizeof(struct hb_filter_private_s));
    hb_filter_private_t *pv = filter->private_data;

    pv->cfr              = init->cfr;
    pv->input_vrate = pv->vrate = init->vrate;
    hb_dict_extract_int(&pv->cfr, filter->settings, "mode");
    hb_dict_extract_rational(&pv->vrate, filter->settings, "rate");

    if (pv->cfr)
    {
        pv->metric = hb_motion_metric_init(init);
        if (pv->metric == NULL)
        {
            return -1;
        }
    }

    // frame-drop analysis always looks at at least 2 buffers
    pv->frame_analysis_depth = 2;

    // Calculate the number of frames we need to keep in order to
    // detect "best" candidate frames to drop.
    double in_vrate  = (double)pv->input_vrate.num / pv->input_vrate.den;
    double out_vrate = (double)pv->vrate.num / pv->vrate.den;
    if (in_vrate > out_vrate)
    {
        // in_vrate / out_vrate tells us how many consecutive repeated
        // frames we can expect to see.  if the number of consecutive
        // repeated frame is < 2, we need the number of consecutive
        // non-repeated frames.  Then add 1 so that we should have
        // transitions that we can detect at both ends of a sequence.
        double factor = in_vrate / out_vrate;
        if (factor > 1.0 && factor < 2.0)
        {
            factor = 1 / (factor - 1);
        }
        pv->frame_analysis_depth = ceil(factor) + 1;

        // if we end up with an absurdly large value, limit it
        if (pv->frame_analysis_depth > MAX_FRAME_ANALYSIS_DEPTH)
        {
            pv->frame_analysis_depth = MAX_FRAME_ANALYSIS_DEPTH;
        }
    }
    pv->frame_analysis_duration = pv->frame_analysis_depth * 90000 / in_vrate;
    pv->frame_metric = calloc(pv->frame_analysis_depth, sizeof(double));
    pv->frame_metric[0] = INT_MAX;

    pv->job = init->job;

    /* Setup FIFO queue for subtitle cache */
    pv->delay_queue = hb_fifo_init( 8, 1 );
    pv->frame_rate_list = hb_list_init();


    /* VFR IVTC needs a bunch of time-keeping variables to track