Function init_legacy_subpass

libswscale/graph.c:363–475

Takes over ownership of `sws` */

/* Takes over ownership of `sws` */
static int init_legacy_subpass(SwsGraph *graph, SwsContext *sws,
                               SwsPass *input, SwsPass **output)
{
    SwsInternal *c = sws_internal(sws);
    const int src_w = sws->src_w, src_h = sws->src_h;
    const int dst_w = sws->dst_w, dst_h = sws->dst_h;
    const int unscaled = src_w == dst_w && src_h == dst_h;
    int align = c->dst_slice_align;
    SwsPass *pass = NULL;
    int ret;

    if (c->cascaded_context[0]) {
        const int num_cascaded = c->cascaded_context[2] ? 3 : 2;
        for (int i = 0; i < num_cascaded; i++) {
            const int is_last = i + 1 == num_cascaded;

            /* Steal cascaded context, so we can manage its lifetime independently */
            SwsContext *sub = c->cascaded_context[i];
            c->cascaded_context[i] = NULL;

            ret = init_legacy_subpass(graph, sub, input, is_last ? output : &input);
            if (ret < 0)
                break;
        }

        sws_free_context(&sws);
        return ret;
    }

    if (sws->dither == SWS_DITHER_ED && !c->convert_unscaled)
        align = 0; /* disable slice threading */

    if (c->src0Alpha && !c->dst0Alpha && isALPHA(sws->dst_format)) {
        ret = ff_sws_graph_add_pass(graph, AV_PIX_FMT_RGBA, src_w, src_h, input,
                                    1, c, run_rgb0, &input);
        if (ret < 0) {
            sws_free_context(&sws);
            return ret;
        }
    }

    if (c->srcXYZ && !(c->dstXYZ && unscaled)) {
        ret = ff_sws_graph_add_pass(graph, AV_PIX_FMT_RGB48, src_w, src_h, input,
                                    1, c, run_xyz2rgb, &input);
        if (ret < 0) {
            sws_free_context(&sws);
            return ret;
        }
    }

    ret = ff_sws_graph_add_pass(graph, sws->dst_format, dst_w, dst_h, input, align, sws,
                                c->convert_unscaled ? run_legacy_unscaled : run_legacy_swscale,
                                &pass);
    if (ret < 0) {
        sws_free_context(&sws);
        return ret;
    }
    pass->setup = setup_legacy_swscale;