[FFmpeg-devel] [PATCH] avfilter/vf_libplacebo: add shader_cache_dir option

[Niklas Haas]

From: Niklas Haas <git at haasn.dev>

Useful to speed up shader compilation. May significantly lower startup
times, in particular with large or complex shaders.

Sponsored-by: nxtedition
---
 doc/filters.texi            |  5 +++++
 libavfilter/vf_libplacebo.c | 29 +++++++++++++++++++++++++++++
 2 files changed, 34 insertions(+)

diff --git a/doc/filters.texi b/doc/filters.texi
index 679b71f290..66cb3e6c20 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -16307,6 +16307,11 @@ as a list of @var{key}=@var{value} pairs separated by ':'. The following example
 shows how to configure a custom filter kernel ("EWA LanczosSharp") and use it
 to double the input image resolution:
 
+ at item shader_cache_dir
+If set to the path of a directory that exists, libplacebo will store and use
+cached shader objects in this directory. This cache is not cleaned up
+automatically.
+
 @example
 -vf "libplacebo=w=iw*2:h=ih*2:extra_opts='upscaler=custom\:upscaler_preset=ewa_lanczos\:upscaler_blur=0.9812505644269356'"
 @end example
diff --git a/libavfilter/vf_libplacebo.c b/libavfilter/vf_libplacebo.c
index 86e1f43dea..ca7d9e253a 100644
--- a/libavfilter/vf_libplacebo.c
+++ b/libavfilter/vf_libplacebo.c
@@ -195,6 +195,11 @@ typedef struct LibplaceboContext {
     int color_trc;
     AVDictionary *extra_opts;
 
+#if PL_API_VER >= 351
+    pl_cache cache;
+    char *shader_cache_dir;
+#endif
+
     int have_hwdevice;
 
     /* pl_render_params */
@@ -522,6 +527,21 @@ static int libplacebo_init(AVFilterContext *avctx)
         return AVERROR(ENOMEM);
     }
 
+#if PL_API_VER >= 351
+    if (s->shader_cache_dir && s->shader_cache_dir[0]) {
+        s->cache = pl_cache_create(pl_cache_params(
+            .log  = s->log,
+            .get  = pl_cache_get_dir,
+            .set  = pl_cache_set_dir,
+            .priv = s->shader_cache_dir,
+        ));
+        if (!s->cache) {
+            libplacebo_uninit(avctx);
+            return AVERROR(ENOMEM);
+        }
+    }
+#endif
+
     if (s->out_format_string) {
         s->out_format = av_get_pix_fmt(s->out_format_string);
         if (s->out_format == AV_PIX_FMT_NONE) {
@@ -676,6 +696,9 @@ static int init_vulkan(AVFilterContext *avctx, const AVVulkanDeviceContext *hwct
     }
 
     s->gpu = s->vulkan->gpu;
+#if PL_API_VER >= 351
+    pl_gpu_set_cache(s->gpu, s->cache);
+#endif
 
     /* Parse the user shaders, if requested */
     if (s->shader_bin_len)
@@ -714,6 +737,9 @@ static void libplacebo_uninit(AVFilterContext *avctx)
         av_freep(&s->inputs);
     }
 
+#if PL_API_VER >= 351
+    pl_cache_destroy(&s->cache);
+#endif
     pl_options_free(&s->opts);
     pl_vulkan_destroy(&s->vulkan);
     pl_log_destroy(&s->log);
@@ -1328,6 +1354,9 @@ static const AVOption libplacebo_options[] = {
     { "fillcolor", "Background fill color", OFFSET(fillcolor), AV_OPT_TYPE_COLOR, {.str = "black at 0"}, .flags = DYNAMIC },
     { "corner_rounding", "Corner rounding radius", OFFSET(corner_rounding), AV_OPT_TYPE_FLOAT, {.dbl = 0.0}, 0.0, 1.0, .flags = DYNAMIC },
     { "extra_opts", "Pass extra libplacebo-specific options using a :-separated list of key=value pairs", OFFSET(extra_opts), AV_OPT_TYPE_DICT, .flags = DYNAMIC },
+#if PL_API_VER >= 351
+    { "shader_cache_dir",  "Set shader cache directory", OFFSET(shader_cache_dir), AV_OPT_TYPE_STRING, {.str=""}, .flags = STATIC },
+#endif
 
     {"colorspace", "select colorspace", OFFSET(colorspace), AV_OPT_TYPE_INT, {.i64=-1}, -1, AVCOL_SPC_NB-1, DYNAMIC, .unit = "colorspace"},
     {"auto", "keep the same colorspace",  0, AV_OPT_TYPE_CONST, {.i64=-1},                          INT_MIN, INT_MAX, STATIC, .unit = "colorspace"},
-- 
2.49.0