Function skip_mode_params

libavcodec/av1dec.c:268–334

}

static void skip_mode_params(AV1DecContext *s)
{
    const AV1RawFrameHeader *header = s->raw_frame_header;
    const AV1RawSequenceHeader *seq = s->raw_seq;

    int forward_idx,  backward_idx;
    int forward_hint, backward_hint;
    int second_forward_idx, second_forward_hint;
    int ref_hint, dist, i;

    if (header->frame_type == AV1_FRAME_KEY ||
        header->frame_type == AV1_FRAME_INTRA_ONLY ||
        !header->reference_select || !seq->enable_order_hint)
        return;

    forward_idx  = -1;
    backward_idx = -1;
    for (i = 0; i < AV1_REFS_PER_FRAME; i++) {
        if (!s->ref[header->ref_frame_idx[i]].raw_frame_header)
            return;
        ref_hint = s->ref[header->ref_frame_idx[i]].raw_frame_header->order_hint;
        dist = get_relative_dist(seq, ref_hint, header->order_hint);
        if (dist < 0) {
            if (forward_idx < 0 ||
                get_relative_dist(seq, ref_hint, forward_hint) > 0) {
                forward_idx  = i;
                forward_hint = ref_hint;
            }
        } else if (dist > 0) {
            if (backward_idx < 0 ||
                get_relative_dist(seq, ref_hint, backward_hint) < 0) {
                backward_idx  = i;
                backward_hint = ref_hint;
            }
        }
    }

    if (forward_idx < 0) {
        return;
    } else if (backward_idx >= 0) {
        s->cur_frame.skip_mode_frame_idx[0] =
            AV1_REF_FRAME_LAST + FFMIN(forward_idx, backward_idx);
        s->cur_frame.skip_mode_frame_idx[1] =
            AV1_REF_FRAME_LAST + FFMAX(forward_idx, backward_idx);
        return;
    }

    second_forward_idx = -1;
    for (i = 0; i < AV1_REFS_PER_FRAME; i++) {
        ref_hint = s->ref[header->ref_frame_idx[i]].raw_frame_header->order_hint;
        if (get_relative_dist(seq, ref_hint, forward_hint) < 0) {
            if (second_forward_idx < 0 ||
                get_relative_dist(seq, ref_hint, second_forward_hint) > 0) {
                second_forward_idx  = i;
                second_forward_hint = ref_hint;
            }
        }
    }