avfilter/vf_libplacebo: support all supported pixfmts

This is done only to the inputs, not the outputs, because we always
output vulkan hwframes.

Doing so also requires keeping track of backing textures for non-hwdec
formats, but is otherwise a mostly straightforward change to the format
query function. Special care needs to be taken to avoid crashing on
older libplacebo due to AV_PIX_FMT_RGBF32LE et al.

libavfilter/vf_libplacebo.c

@@ -62,6 +62,7 @@ typedef struct LibplaceboContext {
     pl_vulkan vulkan;
     pl_gpu gpu;
     pl_renderer renderer;
+    pl_tex tex[4];
 
     /* settings */
     char *out_format_string;
@@ -302,6 +303,8 @@ static void libplacebo_uninit(AVFilterContext *avctx)
 {
     LibplaceboContext *s = avctx->priv;
 
+    for (int i = 0; i < FF_ARRAY_ELEMS(s->tex); i++)
+        pl_tex_destroy(s->gpu, &s->tex[i]);
     for (int i = 0; i < s->num_hooks; i++)
         pl_mpv_user_shader_destroy(&s->hooks[i]);
     pl_renderer_destroy(&s->renderer);
@@ -321,6 +324,7 @@ static int process_frames(AVFilterContext *avctx, AVFrame *out, AVFrame *in)
     struct pl_frame image, target;
     ok = pl_map_avframe_ex(s->gpu, &image, pl_avframe_params(
         .frame    = in,
+        .tex      = s->tex,
         .map_dovi = s->apply_dovi,
     ));
 
@@ -510,22 +514,49 @@ fail:
 static int libplacebo_query_format(AVFilterContext *ctx)
 {
     int err = 0;
-    static const enum AVPixelFormat pix_fmts[] = {
+    LibplaceboContext *s = ctx->priv;
+    const AVPixFmtDescriptor *desc = NULL;
+    AVFilterFormats *in_fmts = NULL;
+    static const enum AVPixelFormat out_fmts[] = {
         AV_PIX_FMT_VULKAN, AV_PIX_FMT_NONE,
     };
 
     RET(init_vulkan(ctx));
 
-    RET(ff_formats_ref(ff_make_format_list(pix_fmts),
-                       &ctx->inputs[0]->outcfg.formats));
-    RET(ff_formats_ref(ff_make_format_list(pix_fmts),
+    while ((desc = av_pix_fmt_desc_next(desc))) {
+
+#if PL_API_VER < 232
+        // Older libplacebo can't handle >64-bit pixel formats, so safe-guard
+        // this to prevent triggering an assertion
+        if (av_get_bits_per_pixel(desc) > 64)
+            continue;
+#endif
+
+        enum AVPixelFormat pixfmt = av_pix_fmt_desc_get_id(desc);
+        if (pl_test_pixfmt(s->gpu, pixfmt)) {
+            if ((err = ff_add_format(&in_fmts, pixfmt)) < 0)
+                return err;
+        }
+    }
+
+    RET(ff_formats_ref(in_fmts, &ctx->inputs[0]->outcfg.formats));
+    RET(ff_formats_ref(ff_make_format_list(out_fmts),
                        &ctx->outputs[0]->incfg.formats));
+
     return 0;
 
 fail:
     return err;
 }
 
+static int libplacebo_config_input(AVFilterLink *inlink)
+{
+    if (inlink->format == AV_PIX_FMT_VULKAN)
+        return ff_vk_filter_config_input(inlink);
+
+    return 0;
+}
+
 static int libplacebo_config_output(AVFilterLink *outlink)
 {
     int err;
@@ -755,7 +786,7 @@ static const AVFilterPad libplacebo_inputs[] = {
         .name         = "default",
         .type         = AVMEDIA_TYPE_VIDEO,
         .filter_frame = &filter_frame,
-        .config_props = &ff_vk_filter_config_input,
+        .config_props = &libplacebo_config_input,
     },
 };