Image enconding and deconding fixes

torchvision/csrc/io/image/cpu/decode_jpeg.cpp

@@ -78,7 +78,7 @@ torch::Tensor decode_jpeg(const torch::Tensor& data, ImageReadMode mode) {
       "Expected a non empty 1-dimensional tensor");
 
   struct jpeg_decompress_struct cinfo;
-  struct torch_jpeg_error_mgr jerr;
+  struct torch_jpeg_error_mgr jerr {};
 
   auto datap = data.data_ptr<uint8_t>();
   // Setup decompression structure

torchvision/csrc/io/image/cpu/decode_png.cpp

@@ -25,8 +25,8 @@ torch::Tensor decode_png(const torch::Tensor& data, ImageReadMode mode) {
   auto info_ptr = png_create_info_struct(png_ptr);
   if (!info_ptr) {
     png_destroy_read_struct(&png_ptr, nullptr, nullptr);
-    // Seems redundant with the if statement. done here to avoid leaking memory.
-    TORCH_CHECK(info_ptr, "libpng info structure allocation failed!")
+    // Seems redundant with the if statement. Done here to avoid leaking memory.
+    TORCH_CHECK(false, "libpng info structure allocation failed!")
   }
 
   auto datap = data.accessor<unsigned char, 1>().data();
@@ -68,7 +68,7 @@ torch::Tensor decode_png(const torch::Tensor& data, ImageReadMode mode) {
 
   if (retval != 1) {
     png_destroy_read_struct(&png_ptr, &info_ptr, nullptr);
-    TORCH_CHECK(retval == 1, "Could read image metadata from content.")
+    TORCH_CHECK(false, "Could read image metadata from content.")
   }
 
   int channels = png_get_channels(png_ptr, info_ptr);

torchvision/csrc/io/image/cpu/encode_jpeg.cpp

@@ -18,8 +18,8 @@ using namespace detail;
 
 torch::Tensor encode_jpeg(const torch::Tensor& data, int64_t quality) {
   // Define compression structures and error handling
-  struct jpeg_compress_struct cinfo;
-  struct torch_jpeg_error_mgr jerr;
+  struct jpeg_compress_struct cinfo {};
+  struct torch_jpeg_error_mgr jerr {};
 
   // Define buffer to write JPEG information to and its size
   unsigned long jpegSize = 0;

torchvision/csrc/io/image/cpu/encode_png.cpp

@@ -47,11 +47,13 @@ void torch_png_write_data(
   size_t nsize = p->size + length;
 
   /* allocate or grow buffer */
+  char* tmp = NULL;
   if (p->buffer)
-    p->buffer = (char*)realloc(p->buffer, nsize);
+    tmp = (char*)realloc(p->buffer, nsize);
   else
-    p->buffer = (char*)malloc(nsize);
+    tmp = (char*)malloc(nsize);
 
+  p->buffer = tmp;
   if (!p->buffer)
     png_error(png_ptr, "Write Error");
 
@@ -64,25 +66,22 @@ void torch_png_write_data(
 
 torch::Tensor encode_png(const torch::Tensor& data, int64_t compression_level) {
   // Define compression structures and error handling
-  png_structp png_write;
-  png_infop info_ptr;
-  struct torch_png_error_mgr err_ptr;
+  png_structp png_write{};
+  png_infop info_ptr{};
+  struct torch_png_error_mgr err_ptr {};
 
   // Define output buffer
-  struct torch_mem_encode buf_info;
-  buf_info.buffer = NULL;
-  buf_info.size = 0;
+  struct torch_mem_encode buf_info {};
 
   /* Establish the setjmp return context for my_error_exit to use. */
   if (setjmp(err_ptr.setjmp_buffer)) {
     /* If we get here, the PNG code has signaled an error.
      * We need to clean up the PNG object and the buffer.
      */
-    if (info_ptr != NULL) {
-      png_destroy_info_struct(png_write, &info_ptr);
-    }
-
     if (png_write != NULL) {
+      if (info_ptr != NULL) {
+        png_destroy_info_struct(png_write, &info_ptr);
+      }
       png_destroy_write_struct(&png_write, NULL);
     }