static int draw_slice(AVFilterLink *inlink, int y0, int h, int slice_dir) { AlphaExtractContext *extract = inlink->dst->priv; AVFilterBufferRef *cur_buf = inlink->cur_buf; AVFilterBufferRef *out_buf = inlink->dst->outputs[0]->out_buf; if (extract->is_packed_rgb) { int x, y; uint8_t *pin, *pout; for (y = y0; y < (y0 + h); y++) { pin = cur_buf->data[0] + y * cur_buf->linesize[0] + extract->rgba_map[A]; pout = out_buf->data[0] + y * out_buf->linesize[0]; for (x = 0; x < out_buf->video->w; x++) { *pout = *pin; pout += 1; pin += 4; } } } else if (cur_buf->linesize[A] == out_buf->linesize[Y]) { const int linesize = cur_buf->linesize[A]; memcpy(out_buf->data[Y] + y0 * linesize, cur_buf->data[A] + y0 * linesize, linesize * h); } else { const int linesize = FFMIN(out_buf->linesize[Y], cur_buf->linesize[A]); int y; for (y = y0; y < (y0 + h); y++) { memcpy(out_buf->data[Y] + y * out_buf->linesize[Y], cur_buf->data[A] + y * cur_buf->linesize[A], linesize); } } return ff_draw_slice(inlink->dst->outputs[0], y0, h, slice_dir); }