jpeg: auto-detect jpeg_mem_src and jpeg_mem_dest

If not defined (e.g. libjpeg < v8) then return a meaningful error at
runtime.

3 files changed, 53 insertions, 3 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index c9e3320..d19b863 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -46,6 +46,17 @@ ENDIF()
 if (JPEG_FOUND)
     SET(src jpeg.c)
     include_directories (${JPEG_INCLUDE_DIR})
+    SET(CMAKE_REQUIRED_INCLUDES "${JPEG_INCLUDE_DIR}")
+    SET(CMAKE_REQUIRED_LIBRARIES "${JPEG_LIBRARY}")
+    INCLUDE(CheckSymbolExists)
+    CHECK_SYMBOL_EXISTS(jpeg_mem_src "stddef.h;stdio.h;jpeglib.h" HAVE_JPEG_MEM_SRC)
+    IF (HAVE_JPEG_MEM_SRC)
+      SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -DHAVE_JPEG_MEM_SRC")
+    ENDIF (HAVE_JPEG_MEM_SRC)
+    CHECK_SYMBOL_EXISTS(jpeg_mem_dest "stddef.h;stdio.h;jpeglib.h" HAVE_JPEG_MEM_DEST)
+    IF (HAVE_JPEG_MEM_DEST)
+      SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -DHAVE_JPEG_MEM_DEST")
+    ENDIF (HAVE_JPEG_MEM_DEST)
     ADD_TORCH_PACKAGE(jpeg "${src}" "${luasrc}" "Image Processing")
     TARGET_LINK_LIBRARIES(jpeg luaT TH ${JPEG_LIBRARIES})
     IF(LUALIB)
diff --git a/generic/jpeg.c b/generic/jpeg.c
index e904171..1fd1e70 100755
--- a/generic/jpeg.c
+++ b/generic/jpeg.c
@@ -189,6 +189,14 @@ static int libjpeg_(Main_size)(lua_State *L)
 
 static int libjpeg_(Main_load)(lua_State *L)
 {
+  const int load_from_file = luaL_checkint(L, 1);
+
+#if !defined(HAVE_JPEG_MEM_SRC)
+  if (load_from_file != 1) {
+    luaL_error(L, JPEG_MEM_SRC_ERR_MSG);
+  }
+#endif
+
   /* This struct contains the JPEG decompression parameters and pointers to
    * working space (which is allocated as needed by the JPEG library).
    */
@@ -207,7 +215,6 @@ static int libjpeg_(Main_load)(lua_State *L)
   int i, k;
 
   THTensor *tensor = NULL;
-  const int load_from_file = luaL_checkint(L, 1);
 
   if (load_from_file == 1) {
     const char *filename = luaL_checkstring(L, 2);
@@ -369,6 +376,14 @@ static int libjpeg_(Main_load)(lua_State *L)
  *
  */
 int libjpeg_(Main_save)(lua_State *L) {
+  const int save_to_file = luaL_checkint(L, 3);
+
+#if !defined(HAVE_JPEG_MEM_DEST)
+  if (save_to_file != 1) {
+    luaL_error(L, JPEG_MEM_DEST_ERR_MSG);
+  }
+#endif
+
   unsigned char *inmem = NULL;  /* destination memory (if saving to memory) */
   unsigned long inmem_size = 0;  /* destination memory size (bytes) */
 
@@ -378,8 +393,6 @@ int libjpeg_(Main_save)(lua_State *L) {
   THTensor *tensorc = THTensor_(newContiguous)(tensor);
   real *tensor_data = THTensor_(data)(tensorc);
 
-  const int save_to_file = luaL_checkint(L, 3);
-
   THByteTensor* tensor_dest = NULL;
   if (save_to_file == 0) {
     tensor_dest = luaT_checkudata(L, 5, "torch.ByteTensor");
diff --git a/jpeg.c b/jpeg.c
index d36f221..ae4ce14 100644
--- a/jpeg.c
+++ b/jpeg.c
@@ -13,6 +13,32 @@
 #define torch_Tensor TH_CONCAT_STRING_3(torch., Real, Tensor)
 #define libjpeg_(NAME) TH_CONCAT_3(libjpeg_, Real, NAME)
 
+static void
+jpeg_mem_src_dummy(j_decompress_ptr c, unsigned char *ibuf, unsigned long isiz)
+{
+}
+
+static void
+jpeg_mem_dest_dummy(j_compress_ptr c, unsigned char **obuf, unsigned long *osiz)
+{
+}
+
+#define JPEG_MEM_SRC_NOT_DEF  "`jpeg_mem_src` is not defined."
+#define JPEG_MEM_DEST_NOT_DEF "`jpeg_mem_dest` is not defined."
+#define JPEG_REQUIRED_VERSION " Use libjpeg v8+, libjpeg-turbo 1.3+ or build" \
+                              " libjpeg-turbo with `--with-mem-srcdst`."
+
+#define JPEG_MEM_SRC_ERR_MSG  JPEG_MEM_SRC_NOT_DEF JPEG_REQUIRED_VERSION
+#define JPEG_MEM_DEST_ERR_MSG JPEG_MEM_DEST_NOT_DEF JPEG_REQUIRED_VERSION
+
+#if !defined(HAVE_JPEG_MEM_SRC)
+#define jpeg_mem_src jpeg_mem_src_dummy
+#endif
+
+#if !defined(HAVE_JPEG_MEM_DEST)
+#define jpeg_mem_dest jpeg_mem_dest_dummy
+#endif
+
 #include "generic/jpeg.c"
 #include "THGenerateAllTypes.h"