static av_always_inline void backup_mb_border(H264Context *h, uint8_t *src_y,
                                              uint8_t *src_cb, uint8_t *src_cr,
                                              int linesize, int uvlinesize,
                                              int simple)
{
    uint8_t *top_border;
    int top_idx = 1;
    const int pixel_shift = h->pixel_shift;
    int chroma444 = CHROMA444(h);
    int chroma422 = CHROMA422(h);

    src_y  -= linesize;
    src_cb -= uvlinesize;
    src_cr -= uvlinesize;

    if (!simple && FRAME_MBAFF(h)) {
        if (h->mb_y & 1) {
            if (!MB_MBAFF(h)) {
                top_border = h->top_borders[0][h->mb_x];
                AV_COPY128(top_border, src_y + 15 * linesize);
                if (pixel_shift)
                    AV_COPY128(top_border + 16, src_y + 15 * linesize + 16);
                if (simple || !CONFIG_GRAY || !(h->flags & CODEC_FLAG_GRAY)) {
                    if (chroma444) {
                        if (pixel_shift) {
                            AV_COPY128(top_border + 32, src_cb + 15 * uvlinesize);
                            AV_COPY128(top_border + 48, src_cb + 15 * uvlinesize + 16);
                            AV_COPY128(top_border + 64, src_cr + 15 * uvlinesize);
                            AV_COPY128(top_border + 80, src_cr + 15 * uvlinesize + 16);
                        } else {
                            AV_COPY128(top_border + 16, src_cb + 15 * uvlinesize);
                            AV_COPY128(top_border + 32, src_cr + 15 * uvlinesize);
                        }
                    } else if (chroma422) {
                        if (pixel_shift) {
                            AV_COPY128(top_border + 32, src_cb + 15 * uvlinesize);
                            AV_COPY128(top_border + 48, src_cr + 15 * uvlinesize);
                        } else {
                            AV_COPY64(top_border + 16, src_cb + 15 * uvlinesize);
                            AV_COPY64(top_border + 24, src_cr + 15 * uvlinesize);
                        }
                    } else {
                        if (pixel_shift) {
                            AV_COPY128(top_border + 32, src_cb + 7 * uvlinesize);
                            AV_COPY128(top_border + 48, src_cr + 7 * uvlinesize);
                        } else {
                            AV_COPY64(top_border + 16, src_cb + 7 * uvlinesize);
                            AV_COPY64(top_border + 24, src_cr + 7 * uvlinesize);
                        }
                    }
                }
            }
        } else if (MB_MBAFF(h)) {
            top_idx = 0;
        } else
            return;
    }

    top_border = h->top_borders[top_idx][h->mb_x];
    /* There are two lines saved, the line above the top macroblock
     * of a pair, and the line above the bottom macroblock. */
    AV_COPY128(top_border, src_y + 16 * linesize);
    if (pixel_shift)
        AV_COPY128(top_border + 16, src_y + 16 * linesize + 16);

    if (simple || !CONFIG_GRAY || !(h->flags & CODEC_FLAG_GRAY)) {
        if (chroma444) {
            if (pixel_shift) {
                AV_COPY128(top_border + 32, src_cb + 16 * linesize);
                AV_COPY128(top_border + 48, src_cb + 16 * linesize + 16);
                AV_COPY128(top_border + 64, src_cr + 16 * linesize);
                AV_COPY128(top_border + 80, src_cr + 16 * linesize + 16);
            } else {
                AV_COPY128(top_border + 16, src_cb + 16 * linesize);
                AV_COPY128(top_border + 32, src_cr + 16 * linesize);
            }
        } else if (chroma422) {
            if (pixel_shift) {
                AV_COPY128(top_border + 32, src_cb + 16 * uvlinesize);
                AV_COPY128(top_border + 48, src_cr + 16 * uvlinesize);
            } else {
                AV_COPY64(top_border + 16, src_cb + 16 * uvlinesize);
                AV_COPY64(top_border + 24, src_cr + 16 * uvlinesize);
            }
        } else {
            if (pixel_shift) {
                AV_COPY128(top_border + 32, src_cb + 8 * uvlinesize);
                AV_COPY128(top_border + 48, src_cr + 8 * uvlinesize);
            } else {
                AV_COPY64(top_border + 16, src_cb + 8 * uvlinesize);
                AV_COPY64(top_border + 24, src_cr + 8 * uvlinesize);
            }
        }
    }
}

Unknown