vo_opengl: gl_lcms: replace icc-cache by icc-cache-dir

This now stores caches for multiple ICC profiles, potentially all the
user has ever used. The big use case for this is for users with multiple
monitors. The old logic would mandate recomputing the LUT and discarding
the cache whenever dragging mpv from one screen to another.

This also avoids having to save and check the ICC profile itself, since
the file name already uniquely determines it.

2 files changed, 33 insertions, 24 deletions

diff --git a/video/out/gl_lcms.c b/video/out/gl_lcms.c
index ab273ffc0b..e49ce77a23 100644
--- a/video/out/gl_lcms.c
+++ b/video/out/gl_lcms.c
@@ -39,6 +39,8 @@
 #if HAVE_LCMS2
 
 #include <lcms2.h>
+#include <libavutil/sha.h>
+#include <libavutil/mem.h>
 
 struct gl_lcms {
     void *icc_data;
@@ -77,9 +79,11 @@ const struct m_sub_options mp_icc_conf = {
     .opts = (const m_option_t[]) {
         OPT_STRING("icc-profile", profile, 0),
         OPT_FLAG("icc-profile-auto", profile_auto, 0),
-        OPT_STRING("icc-cache", cache, 0),
+        OPT_STRING("icc-cache-dir", cache_dir, 0),
         OPT_INT("icc-intent", intent, 0),
         OPT_STRING_VALIDATE("3dlut-size", size_str, 0, validate_3dlut_size_opt),
+
+        OPT_REMOVED("icc-cache", "see icc-cache-dir"),
         {0}
     },
     .size = sizeof(struct mp_icc_opts),
@@ -185,8 +189,6 @@ bool gl_lcms_has_changed(struct gl_lcms *p)
     return change;
 }
 
-#define LUT3D_CACHE_HEADER "mpv 3dlut cache 1.0\n"
-
 bool gl_lcms_get_lut3d(struct gl_lcms *p, struct lut3d **result_lut3d)
 {
     int s_r, s_g, s_b;
@@ -203,27 +205,36 @@ bool gl_lcms_get_lut3d(struct gl_lcms *p, struct lut3d **result_lut3d)
     struct lut3d *lut = NULL;
     cmsContext cms = NULL;
 
-    char *cache_info =
+    char *cache_file = NULL;
+    if (p->opts.cache_dir) {
         // Gamma is included in the header to help uniquely identify it,
         // because we may change the parameter in the future or make it
         // customizable, same for the primaries.
-        talloc_asprintf(tmp, "intent=%d, size=%dx%dx%d, gamma=2.4, prim=bt2020\n",
-                        p->opts.intent, s_r, s_g, s_b);
-
-    bstr iccdata = (bstr) {
-        .start = p->icc_data,
-        .len   = p->icc_size,
-    };
+        char *cache_info = talloc_asprintf(tmp,
+                "ver=1.1, intent=%d, size=%dx%dx%d, gamma=2.4, prim=bt2020\n",
+                p->opts.intent, s_r, s_g, s_b);
+
+        uint8_t hash[32];
+        struct AVSHA *sha = av_sha_alloc();
+        if (!sha)
+            abort();
+        av_sha_init(sha, 256);
+        av_sha_update(sha, cache_info, strlen(cache_info));
+        av_sha_update(sha, p->icc_data, p->icc_size);
+        av_sha_final(sha, hash);
+        av_free(sha);
+
+        cache_file = talloc_strdup(tmp, p->opts.cache_dir);
+        cache_file = talloc_asprintf_append(cache_file, "/");
+        for (int i = 0; i < sizeof(hash); i++)
+            cache_file = talloc_asprintf_append(cache_file, "%02X", hash[i]);
+    }
 
     // check cache
-    if (p->opts.cache) {
-        MP_INFO(p, "Opening 3D LUT cache in file '%s'.\n", p->opts.cache);
-        struct bstr cachedata = load_file(tmp, p->opts.cache, p->global);
-        if (bstr_eatstart(&cachedata, bstr0(LUT3D_CACHE_HEADER))
-            && bstr_eatstart(&cachedata, bstr0(cache_info))
-            && bstr_eatstart(&cachedata, iccdata)
-            && cachedata.len == talloc_get_size(output))
-        {
+    if (cache_file) {
+        MP_INFO(p, "Opening 3D LUT cache in file '%s'.\n", cache_file);
+        struct bstr cachedata = load_file(tmp, cache_file, p->global);
+        if (cachedata.len == talloc_get_size(output)) {
             memcpy(output, cachedata.start, cachedata.len);
             goto done;
         } else {
@@ -284,12 +295,10 @@ bool gl_lcms_get_lut3d(struct gl_lcms *p, struct lut3d **result_lut3d)
 
     cmsDeleteTransform(trafo);
 
-    if (p->opts.cache) {
-        char *fname = mp_get_user_path(NULL, p->global, p->opts.cache);
+    if (cache_file) {
+        char *fname = mp_get_user_path(NULL, p->global, cache_file);
         FILE *out = fopen(fname, "wb");
         if (out) {
-            fprintf(out, "%s%s", LUT3D_CACHE_HEADER, cache_info);
-            fwrite(p->icc_data, p->icc_size, 1, out);
             fwrite(output, talloc_get_size(output), 1, out);
             fclose(out);
         }
diff --git a/video/out/gl_lcms.h b/video/out/gl_lcms.h
index 883b485f66..5ad08b7d64 100644
--- a/video/out/gl_lcms.h
+++ b/video/out/gl_lcms.h
@@ -10,7 +10,7 @@ extern const struct m_sub_options mp_icc_conf;
 struct mp_icc_opts {
     char *profile;
     int profile_auto;
-    char *cache;
+    char *cache_dir;
     char *size_str;
     int intent;
 };