static void gif_fill_rect(AVFrame *picture, uint32_t color, int l, int t, int w, int h) { const int linesize = picture->linesize[0] / sizeof(uint32_t); const uint32_t *py = (uint32_t *)picture->data[0] + t * linesize; const uint32_t *pr, *pb = py + (t + h) * linesize; uint32_t *px; for (; py < pb; py += linesize) { px = (uint32_t *)py + l; pr = px + w; for (; px < pr; px++) *px = color; } }