[x265] [PATCH 2 of 2] api: fallback to multilib library if profile-named library not found (refs #156)

[Steve Borho]

# HG changeset patch
# User Steve Borho <steve at borho.org>
# Date 1439550912 -19800
#      Fri Aug 14 16:45:12 2015 +0530
# Node ID b7c1efea98a9c91d92983dab02828c03a7a44139
# Parent  598a3eee33da4bb4b5bea2ad098fa30724a0cb2f
api: fallback to multilib library if profile-named library not found (refs #156)

If you call x265_api_get(10) and libx265_main10.dll is not found, it will now
fallback to trying to bind libx265.dll and request bitDepth 10 from that library
(in the hope that it is a multilib library supporting all bit depths)

diff -r 598a3eee33da -r b7c1efea98a9 doc/reST/api.rst
--- a/doc/reST/api.rst	Fri Aug 14 16:28:19 2015 +0530
+++ b/doc/reST/api.rst	Fri Aug 14 16:45:12 2015 +0530
@@ -485,6 +485,10 @@
 	10-bit: libx265_main10
 	12-bit: libx265_main12
 
+If the profile-named library is not found, it will then try to bind a
+generic libx265 in the hopes that it is a multilib library with all bit
+depths.
+
 Packaging and Distribution
 --------------------------
 
diff -r 598a3eee33da -r b7c1efea98a9 source/encoder/api.cpp
--- a/source/encoder/api.cpp	Fri Aug 14 16:28:19 2015 +0530
+++ b/source/encoder/api.cpp	Fri Aug 14 16:45:12 2015 +0530
@@ -353,6 +353,7 @@
 
         const char* libname = NULL;
         const char* method = "x265_api_get_" xstr(X265_BUILD);
+        const char* multilibname = "libx265" ext;
 
         if (bitDepth == 12)
             libname = "libx265_main12" ext;
@@ -364,22 +365,33 @@
             return NULL;
 
         const x265_api* api = NULL;
+        int reqDepth = 0;
 
 #if _WIN32
         HMODULE h = LoadLibraryA(libname);
+        if (!h)
+        {
+            h = LoadLibraryA(multilibname);
+            reqDepth = bitDepth;
+        }
         if (h)
         {
             api_get_func get = (api_get_func)GetProcAddress(h, method);
             if (get)
-                api = get(0);
+                api = get(reqDepth);
         }
 #else
         void* h = dlopen(libname, RTLD_LAZY | RTLD_LOCAL);
+        if (!h)
+        {
+            h = dlopen(multilibname, RTLD_LAZY | RTLD_LOCAL);
+            reqDepth = bitDepth;
+        }
         if (h)
         {
             api_get_func get = (api_get_func)dlsym(h, method);
             if (get)
-                api = get(0);
+                api = get(reqDepth);
         }
 #endif
 
@@ -420,6 +432,7 @@
 
         const char* libname = NULL;
         const char* method = "x265_api_query";
+        const char* multilibname = "libx265" ext;
 
         if (bitDepth == 12)
             libname = "libx265_main12" ext;
@@ -434,25 +447,36 @@
         }
 
         const x265_api* api = NULL;
+        int reqDepth = 0;
         int e = X265_API_QUERY_ERR_LIB_NOT_FOUND;
 
 #if _WIN32
         HMODULE h = LoadLibraryA(libname);
+        if (!h)
+        {
+            h = LoadLibraryA(multilibname);
+            reqDepth = bitDepth;
+        }
         if (h)
         {
             e = X265_API_QUERY_ERR_FUNC_NOT_FOUND;
             api_query_func query = (api_query_func)GetProcAddress(h, method);
             if (query)
-                api = query(bitDepth, apiVersion, err);
+                api = query(reqDepth, apiVersion, err);
         }
 #else
         void* h = dlopen(libname, RTLD_LAZY | RTLD_LOCAL);
+        if (!h)
+        {
+            h = dlopen(multilibname, RTLD_LAZY | RTLD_LOCAL);
+            reqDepth = bitDepth;
+        }
         if (h)
         {
             e = X265_API_QUERY_ERR_FUNC_NOT_FOUND;
             api_query_func query = (api_query_func)dlsym(h, method);
             if (query)
-                api = query(bitDepth, apiVersion, err);
+                api = query(reqDepth, apiVersion, err);
         }
 #endif