static void hscroll(AVCodecContext *avctx)
{
    AnsiContext *s = avctx->priv_data;
    int i;

    if (s->y <= avctx->height - 2*s->font_height) {
        s->y += s->font_height;
        return;
    }

    i = 0;
    for (; i < avctx->height - s->font_height; i++)
        memcpy(s->frame->data[0] + i * s->frame->linesize[0],
               s->frame->data[0] + (i + s->font_height) * s->frame->linesize[0],
               avctx->width);
    for (; i < avctx->height; i++)
        memset(s->frame->data[0] + i * s->frame->linesize[0],
            DEFAULT_BG_COLOR, avctx->width);
}
Unknown