use dummy decoder plugin for 'uncompressed' (#1347)

examples/heif_dec.cc

@@ -188,11 +188,8 @@ void list_all_decoders()
   std::cout << "JPEG 2000 (HT) decoders:\n";
   list_decoders(heif_compression_HTJ2K);
 
-#if WITH_UNCOMPRESSED_CODEC
-  std::cout << "uncompressed: yes\n";
-#else
-  std::cout << "uncompressed: no\n";
-#endif
+  std::cout << "uncompressed:\n";
+  list_decoders(heif_compression_uncompressed);
 
   std::cout << "VVIC decoders:\n";
   list_decoders(heif_compression_VVC);

libheif/api/libheif/heif.cc

@@ -2832,13 +2832,6 @@ struct heif_error heif_context_get_encoder(struct heif_context* context,
 
 int heif_have_decoder_for_format(enum heif_compression_format format)
 {
-  if (format == heif_compression_uncompressed) {
-#if WITH_UNCOMPRESSED_CODEC
-    return true;
-#else
-    return false;
-#endif
-  }
   auto plugin = get_decoder(format, nullptr);
   return plugin != nullptr;
 }

libheif/plugin_registry.cc

@@ -76,6 +76,7 @@
 
 #if WITH_UNCOMPRESSED_CODEC
 #include "plugins/encoder_uncompressed.h"
+#include "plugins/decoder_uncompressed.h"
 #endif
 
 #if HAVE_JPEG_DECODER
@@ -213,9 +214,10 @@ void register_default_plugins()
 
 #if WITH_UNCOMPRESSED_CODEC
   register_encoder(get_encoder_plugin_uncompressed());
+  register_decoder(get_decoder_plugin_uncompressed());
 #endif
 
-register_encoder(get_encoder_plugin_mask());
+  register_encoder(get_encoder_plugin_mask());
 }
 
 

libheif/plugins/CMakeLists.txt

@@ -121,5 +121,7 @@ target_sources(heif PRIVATE
 if (WITH_UNCOMPRESSED_CODEC)
     target_sources(heif PRIVATE
             encoder_uncompressed.h
-            encoder_uncompressed.cc)
+            encoder_uncompressed.cc
+            decoder_uncompressed.h
+            decoder_uncompressed.cc)
 endif ()

libheif/plugins/decoder_uncompressed.cc

@@ -0,0 +1,72 @@
+/*
+ * JPEG codec.
+ * Copyright (c) 2023 Dirk Farin <[email protected]>
+ *
+ * This file is part of libheif.
+ *
+ * libheif is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version.
+ *
+ * libheif is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with libheif.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "libheif/heif.h"
+#include "libheif/heif_plugin.h"
+#include "decoder_uncompressed.h"
+
+struct uncompressed_decoder
+{
+};
+
+static const char kSuccess[] = "Success";
+
+static const int UNCOMPRESSED_PLUGIN_PRIORITY = 100;
+
+
+static const char* uncompressed_plugin_name()
+{
+  return "builtin";
+}
+
+
+static int uncompressed_does_support_format(enum heif_compression_format format)
+{
+  if (format == heif_compression_uncompressed) {
+    return UNCOMPRESSED_PLUGIN_PRIORITY;
+  }
+  else {
+    return 0;
+  }
+}
+
+
+
+
+static const struct heif_decoder_plugin decoder_uncompressed
+    {
+        3,
+        uncompressed_plugin_name,
+        nullptr,
+        nullptr,
+        uncompressed_does_support_format,
+        nullptr,
+        nullptr,
+        nullptr,
+        nullptr,
+        nullptr,
+        "uncompressed"
+    };
+
+
+const struct heif_decoder_plugin* get_decoder_plugin_uncompressed()
+{
+  return &decoder_uncompressed;
+}

libheif/plugins/decoder_uncompressed.h

@@ -0,0 +1,28 @@
+/*
+ * Dummy decoder plugin for the 'uncompressed' codec.
+ * Copyright (c) 2023 Dirk Farin <[email protected]>
+ *
+ * This file is part of libheif.
+ *
+ * libheif is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version.
+ *
+ * libheif is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with libheif.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef LIBHEIF_DECODER_UNCOMPRESSED_H
+#define LIBHEIF_DECODER_UNCOMPRESSED_H
+
+#include "common_utils.h"
+
+const struct heif_decoder_plugin* get_decoder_plugin_uncompressed();
+
+#endif