Merge pull request #1716 from image-rs/exr-on-little-endian

Restrict openexr to little endian platforms

Cargo.toml

@@ -43,9 +43,13 @@ rgb = { version = "0.8.25", optional = true }
 mp4parse = { version = "0.12.0", optional = true }
 dav1d = { version = "0.6.0", optional = true }
 dcv-color-primitives = { version = "0.4.0", optional = true }
-exr = { version = "1.4.2", optional = true }
 color_quant = "1.1"
 
+# These appear as an empty dependency on other platforms.
+# See: <https://github.com/rust-lang/cargo/issues/1197#issuecomment-901794879>
+[target.'cfg(target_endian = "little")'.dependencies]
+exr = { version = "1.4.2", optional = true }
+
 [dev-dependencies]
 crc32fast = "1.2.0"
 num-complex = "0.4"

src/codecs/openexr.rs

@@ -20,8 +20,6 @@
 //!     - meta data is lost
 //!     - dwaa/dwab compressed images not supported yet by the exr library
 //!     - (chroma) subsampling not supported yet by the exr library
-
-extern crate exr;
 use exr::prelude::*;
 
 use crate::error::{DecodingError, EncodingError, ImageFormatHint};

src/image.rs

@@ -290,7 +290,8 @@ pub enum ImageOutputFormat {
     /// An Image in TGA Format
     Tga,
 
-    #[cfg(feature = "openexr")]
+    #[cfg(feature = "exr")]
+    #[cfg(target_endian = "little")]
     /// An Image in OpenEXR Format
     OpenExr,
 
@@ -327,7 +328,8 @@ impl From<ImageFormat> for ImageOutputFormat {
             ImageFormat::Farbfeld => ImageOutputFormat::Farbfeld,
             #[cfg(feature = "tga")]
             ImageFormat::Tga => ImageOutputFormat::Tga,
-            #[cfg(feature = "openexr")]
+            #[cfg(feature = "exr")]
+            #[cfg(target_endian = "little")]
             ImageFormat::OpenExr => ImageOutputFormat::OpenExr,
             #[cfg(feature = "tiff")]
             ImageFormat::Tiff => ImageOutputFormat::Tiff,

src/io/free_functions.rs

@@ -72,7 +72,8 @@ pub(crate) fn load_decoder<R: BufRead + Seek, V: DecoderVisitor>(
         image::ImageFormat::Ico => visitor.visit_decoder(ico::IcoDecoder::new(r)?),
         #[cfg(feature = "hdr")]
         image::ImageFormat::Hdr => visitor.visit_decoder(hdr::HdrAdapter::new(BufReader::new(r))?),
-        #[cfg(feature = "openexr")]
+        #[cfg(feature = "exr")]
+        #[cfg(target_endian = "little")]
         image::ImageFormat::OpenExr => visitor.visit_decoder(openexr::OpenExrDecoder::new(r)?),
         #[cfg(feature = "pnm")]
         image::ImageFormat::Pnm => visitor.visit_decoder(pnm::PnmDecoder::new(r)?),
@@ -230,7 +231,8 @@ pub(crate) fn write_buffer_impl<W: std::io::Write + Seek>(
         ImageOutputFormat::Tga => {
             tga::TgaEncoder::new(buffered_write).write_image(buf, width, height, color)
         }
-        #[cfg(feature = "openexr")]
+        #[cfg(feature = "exr")]
+        #[cfg(target_endian = "little")]
         ImageOutputFormat::OpenExr => {
             openexr::OpenExrEncoder::new(buffered_write).write_image(buf, width, height, color)
         }

src/lib.rs

@@ -234,7 +234,8 @@ pub mod codecs {
     pub mod ico;
     #[cfg(feature = "jpeg")]
     pub mod jpeg;
-    #[cfg(feature = "openexr")]
+    #[cfg(feature = "exr")]
+    #[cfg(target_endian = "little")]
     pub mod openexr;
     #[cfg(feature = "png")]
     pub mod png;