Add HEIF support

Support the HEIF format using libheif.

2 files changed, 124 insertions, 0 deletions

diff --git a/src/backend_libheif.c b/src/backend_libheif.c
new file mode 100644
index 0000000..8264e87
--- /dev/null
+++ b/src/backend_libheif.c
@@ -0,0 +1,119 @@
+#include <stdlib.h>
+#include <string.h>
+#include <libheif/heif.h>
+
+#include "backend.h"
+#include "bitmap.h"
+#include "image.h"
+#include "source_private.h"
+
+struct private {
+  struct heif_image *img;
+};
+
+static void free_private(void *raw_private)
+{
+  if (!raw_private) {
+    return;
+  }
+  struct private *private = raw_private;
+  heif_image_release(private->img);
+  free(private);
+}
+
+static void load_image(void *raw_private, struct imv_image **image, int *frametime)
+{
+  *image = NULL;
+  *frametime = 0;
+
+  struct private *private = raw_private;
+
+  int stride;
+  const uint8_t *data = heif_image_get_plane_readonly(private->img, heif_channel_interleaved, &stride);
+
+  int width = heif_image_get_width(private->img, heif_channel_interleaved);
+  int height = heif_image_get_height(private->img, heif_channel_interleaved);
+  unsigned char *bitmap = malloc(width * height * 4);
+  memcpy(bitmap, data, width * height * 4);
+
+  struct imv_bitmap *bmp = malloc(sizeof *bmp);
+  bmp->width = width,
+  bmp->height = height,
+  bmp->format = IMV_ABGR;
+  bmp->data = bitmap;
+  *image = imv_image_create_from_bitmap(bmp);
+}
+
+static const struct imv_source_vtable vtable = {
+  .load_first_frame = load_image,
+  .free = free_private,
+};
+
+struct heif_error get_primary_image(struct heif_context *ctx, struct heif_image **img)
+{
+  struct heif_image_handle *handle;
+  struct heif_error err = heif_context_get_primary_image_handle(ctx, &handle);
+  if (err.code != heif_error_Ok) {
+    return err;
+  }
+
+  err = heif_decode_image(handle, img, heif_colorspace_RGB, heif_chroma_interleaved_RGBA, NULL);
+  heif_image_handle_release(handle);
+  return err;
+}
+
+static enum backend_result open_path(const char *path, struct imv_source **src)
+{
+  struct heif_context *ctx = heif_context_alloc();
+  struct heif_error err = heif_context_read_from_file(ctx, path, NULL); // TODO: error
+  if (err.code != heif_error_Ok) {
+    heif_context_free(ctx);
+    if (err.code == heif_error_Input_does_not_exist) {
+      return BACKEND_BAD_PATH;
+    }
+    return BACKEND_UNSUPPORTED;
+  }
+
+  struct heif_image *img;
+  err = get_primary_image(ctx, &img);
+  heif_context_free(ctx);
+  if (err.code != heif_error_Ok) {
+    return BACKEND_UNSUPPORTED;
+  }
+
+  struct private *private = malloc(sizeof *private);
+  private->img = img;
+  *src = imv_source_create(&vtable, private);
+  return BACKEND_SUCCESS;
+}
+
+static enum backend_result open_memory(void *data, size_t len, struct imv_source **src)
+{
+  struct heif_context *ctx = heif_context_alloc();
+  struct heif_error err = heif_context_read_from_memory_without_copy(ctx, data, len, NULL);
+  if (err.code != heif_error_Ok) {
+    heif_context_free(ctx);
+    return BACKEND_UNSUPPORTED;
+  }
+
+  struct heif_image *img;
+  err = get_primary_image(ctx, &img);
+  heif_context_free(ctx);
+  if (err.code != heif_error_Ok) {
+    return BACKEND_UNSUPPORTED;
+  }
+
+  struct private *private = malloc(sizeof *private);
+  private->img = img;
+  *src = imv_source_create(&vtable, private);
+  return BACKEND_SUCCESS;
+}
+
+const struct imv_backend imv_backend_libheif = {
+  .name = "libheif",
+  .description = "ISO/IEC 23008-12:2017 HEIF file format decoder and encoder.",
+  .website = "http://www.libheif.org",
+  .license = "GNU Lesser General Public License",
+  .open_path = &open_path,
+  .open_memory = &open_memory,
+};
diff --git a/src/main.c b/src/main.c
index cb0db83..1e11f07 100644
--- a/src/main.c
+++ b/src/main.c
@@ -8,6 +8,7 @@ extern const struct imv_backend imv_backend_librsvg;
 extern const struct imv_backend imv_backend_libtiff;
 extern const struct imv_backend imv_backend_libjpeg;
 extern const struct imv_backend imv_backend_libnsgif;
+extern const struct imv_backend imv_backend_libheif;
 
 int main(int argc, char **argv)
 {
@@ -41,6 +42,10 @@ int main(int argc, char **argv)
   imv_install_backend(imv, &imv_backend_freeimage);
 #endif
 
+#ifdef IMV_BACKEND_LIBHEIF
+  imv_install_backend(imv, &imv_backend_libheif);
+#endif
+
   if (!imv_load_config(imv)) {
     imv_free(imv);
     return 1;