Merge branch 'feature/upstream' into develop

14 files changed, 1094 insertions, 185 deletions

diff --git a/src/photos/AvifSupport.vala b/src/photos/AvifSupport.vala
new file mode 100644
index 0000000..842f0fc
--- /dev/null
+++ b/src/photos/AvifSupport.vala
@@ -0,0 +1,140 @@
+/* Copyright 2016 Software Freedom Conservancy Inc.
+ *
+ * This software is licensed under the GNU LGPL (version 2.1 or later).
+ * See the COPYING file in this distribution.
+ */
+
+class AvifFileFormatProperties : PhotoFileFormatProperties {
+    private static string[] KNOWN_EXTENSIONS = { "avif" };
+    private static string[] KNOWN_MIME_TYPES = { "image/avif" };
+
+    private static AvifFileFormatProperties instance = null;
+
+    public static void init() {
+        instance = new AvifFileFormatProperties();
+    }
+    
+    public static AvifFileFormatProperties get_instance() {
+        return instance;
+    }
+    
+    public override PhotoFileFormat get_file_format() {
+        return PhotoFileFormat.AVIF;
+    }
+    
+    public override PhotoFileFormatFlags get_flags() {
+        return PhotoFileFormatFlags.NONE;
+    }
+
+    public override string get_user_visible_name() {
+        return _("AVIF");
+    }
+
+    public override string get_default_extension() {
+        return KNOWN_EXTENSIONS[0];
+    }
+    
+    public override string[] get_known_extensions() {
+        return KNOWN_EXTENSIONS;
+    }
+    
+    public override string get_default_mime_type() {
+        return KNOWN_MIME_TYPES[0];
+    }
+    
+    public override string[] get_mime_types() {
+        return KNOWN_MIME_TYPES;
+    }
+}
+
+public class AvifSniffer : GdkSniffer {
+    public AvifSniffer(File file, PhotoFileSniffer.Options options) {
+        base (file, options);
+    }
+
+    public override DetectedPhotoInformation? sniff(out bool is_corrupted) throws Error {
+        // Rely on GdkSniffer to detect corruption
+        is_corrupted = false;
+        
+        if (!is_supported_bmff_with_variants(file, {"avif", "avis"}))
+            return null;
+        
+        DetectedPhotoInformation? detected = base.sniff(out is_corrupted);
+        if (detected == null)
+            return null;
+        
+        return (detected.file_format == PhotoFileFormat.AVIF) ? detected : null;
+    }
+}
+
+public class AvifReader : GdkReader {
+    public AvifReader(string filepath) {
+        base (filepath, PhotoFileFormat.AVIF);
+    }
+}
+
+public class AvifWriter : PhotoFileWriter {
+    public AvifWriter(string filepath) {
+        base (filepath, PhotoFileFormat.AVIF);
+    }
+    
+    public override void write(Gdk.Pixbuf pixbuf, Jpeg.Quality quality) throws Error {
+        pixbuf.save(get_filepath(), "avif", "quality", "90", null);
+    }
+}
+
+public class AvifMetadataWriter : PhotoFileMetadataWriter {
+    public AvifMetadataWriter(string filepath) {
+        base (filepath, PhotoFileFormat.AVIF);
+    }
+    
+    public override void write_metadata(PhotoMetadata metadata) throws Error {
+        metadata.write_to_file(get_file());
+    }
+}
+
+public class AvifFileFormatDriver : PhotoFileFormatDriver {
+    private static AvifFileFormatDriver instance = null;
+    
+    public static void init() {
+        instance = new AvifFileFormatDriver();
+        AvifFileFormatProperties.init();
+    }
+    
+    public static AvifFileFormatDriver get_instance() {
+        return instance;
+    }
+    
+    public override PhotoFileFormatProperties get_properties() {
+        return AvifFileFormatProperties.get_instance();
+    }
+    
+    public override PhotoFileReader create_reader(string filepath) {
+        return new AvifReader(filepath);
+    }
+    
+    public override bool can_write_image() {
+        return true;
+    }
+    
+    public override bool can_write_metadata() {
+        return true;
+    }
+    
+    public override PhotoFileWriter? create_writer(string filepath) {
+        return new AvifWriter(filepath);
+    }
+    
+    public override PhotoFileMetadataWriter? create_metadata_writer(string filepath) {
+        return new AvifMetadataWriter(filepath);
+    }
+    
+    public override PhotoFileSniffer create_sniffer(File file, PhotoFileSniffer.Options options) {
+        return new AvifSniffer(file, options);
+    }
+    
+    public override PhotoMetadata create_metadata() {
+        return new PhotoMetadata();
+    }
+}
+
diff --git a/src/photos/BmpSupport.vala b/src/photos/BmpSupport.vala
index a59a4d9..26ec911 100644
--- a/src/photos/BmpSupport.vala
+++ b/src/photos/BmpSupport.vala
@@ -90,33 +90,6 @@ public class BmpReader : GdkReader {
     public BmpReader(string filepath) {
         base (filepath, PhotoFileFormat.BMP);
     }
-    
-    public override Gdk.Pixbuf scaled_read(Dimensions full, Dimensions scaled) throws Error {
-        Gdk.Pixbuf result = null;
-        /* if we encounter a situation where there are two orders of magnitude or more of
-           difference between the full image size and the scaled size, and if the full image
-           size has five or more decimal digits of precision, Gdk.Pixbuf.from_file_at_scale( ) can
-           fail due to what appear to be floating-point round-off issues. This isn't surprising,
-           since 32-bit floats only have 6-7 decimal digits of precision in their mantissa. In
-           this case, we prefetch the image at a larger scale and then downsample it to the
-           desired scale as a post-process step. This short-circuits Gdk.Pixbuf's buggy
-           scaling code. */
-        if (((full.width > 9999) || (full.height > 9999)) && ((scaled.width < 100) ||
-             (scaled.height < 100))) {
-            Dimensions prefetch_dimensions = full.get_scaled_by_constraint(1000,
-                ScaleConstraint.DIMENSIONS);
-                                  
-            result = new Gdk.Pixbuf.from_file_at_scale(get_filepath(), prefetch_dimensions.width,
-                prefetch_dimensions.height, false);
-
-            result = result.scale_simple(scaled.width, scaled.height, Gdk.InterpType.HYPER);
-        } else {
-            result = new Gdk.Pixbuf.from_file_at_scale(get_filepath(), scaled.width,
-                scaled.height, false);
-        }
-
-        return result;
-    }
 }
 
 public class BmpWriter : PhotoFileWriter {
diff --git a/src/photos/GdkSupport.vala b/src/photos/GdkSupport.vala
index f7e18d5..64a08d6 100644
--- a/src/photos/GdkSupport.vala
+++ b/src/photos/GdkSupport.vala
@@ -21,7 +21,30 @@ public abstract class GdkReader : PhotoFileReader {
     }
     
     public override Gdk.Pixbuf scaled_read(Dimensions full, Dimensions scaled) throws Error {
-        return new Gdk.Pixbuf.from_file_at_scale(get_filepath(), scaled.width, scaled.height, false);
+        Gdk.Pixbuf result = null;
+        /* if we encounter a situation where there are two orders of magnitude or more of
+           difference between the full image size and the scaled size, and if the full image
+           size has five or more decimal digits of precision, Gdk.Pixbuf.from_file_at_scale( ) can
+           fail due to what appear to be floating-point round-off issues. This isn't surprising,
+           since 32-bit floats only have 6-7 decimal digits of precision in their mantissa. In
+           this case, we prefetch the image at a larger scale and then downsample it to the
+           desired scale as a post-process step. This short-circuits Gdk.Pixbuf's buggy
+           scaling code. */
+        if (((full.width > 9999) || (full.height > 9999)) && ((scaled.width < 100) ||
+             (scaled.height < 100))) {
+            Dimensions prefetch_dimensions = full.get_scaled_by_constraint(1000,
+                ScaleConstraint.DIMENSIONS);
+                                  
+            result = new Gdk.Pixbuf.from_file_at_scale(get_filepath(), prefetch_dimensions.width,
+                prefetch_dimensions.height, false);
+
+            result = result.scale_simple(scaled.width, scaled.height, Gdk.InterpType.HYPER);
+        } else {
+            result = new Gdk.Pixbuf.from_file_at_scale(get_filepath(), scaled.width,
+                scaled.height, false);
+        }
+
+        return result;
     }
 }
 
@@ -112,13 +135,14 @@ public abstract class GdkSniffer : PhotoFileSniffer {
         Gdk.Pixbuf? pixbuf = pixbuf_loader.get_pixbuf();
         if (pixbuf == null)
             return;
-        
+
         detected.colorspace = pixbuf.get_colorspace();
         detected.channels = pixbuf.get_n_channels();
         detected.bits_per_channel = pixbuf.get_bits_per_sample();
         
         unowned Gdk.PixbufFormat format = pixbuf_loader.get_format();
         detected.format_name = format.get_name();
+        debug("Pixbuf detected format name: %s", detected.format_name);
         detected.file_format = PhotoFileFormat.from_pixbuf_name(detected.format_name);
         
         area_prepared = true;
diff --git a/src/photos/GifSupport.vala b/src/photos/GifSupport.vala
index bd6ef6a..b49b4f2 100644
--- a/src/photos/GifSupport.vala
+++ b/src/photos/GifSupport.vala
@@ -86,33 +86,6 @@ public class GifReader : GdkReader {
     public GifReader(string filepath) {
         base (filepath, PhotoFileFormat.PNG);
     }
-
-    public override Gdk.Pixbuf scaled_read(Dimensions full, Dimensions scaled) throws Error {
-        Gdk.Pixbuf result = null;
-        /* if we encounter a situation where there are two orders of magnitude or more of
-           difference between the full image size and the scaled size, and if the full image
-           size has five or more decimal digits of precision, Gdk.Pixbuf.from_file_at_scale( ) can
-           fail due to what appear to be floating-point round-off issues. This isn't surprising,
-           since 32-bit floats only have 6-7 decimal digits of precision in their mantissa. In
-           this case, we prefetch the image at a larger scale and then downsample it to the
-           desired scale as a post-process step. This short-circuits Gdk.Pixbuf's buggy
-           scaling code. */
-        if (((full.width > 9999) || (full.height > 9999)) && ((scaled.width < 100) ||
-             (scaled.height < 100))) {
-            Dimensions prefetch_dimensions = full.get_scaled_by_constraint(1000,
-                ScaleConstraint.DIMENSIONS);
-
-            result = new Gdk.Pixbuf.from_file_at_scale(get_filepath(), prefetch_dimensions.width,
-                prefetch_dimensions.height, false);
-
-            result = result.scale_simple(scaled.width, scaled.height, Gdk.InterpType.HYPER);
-        } else {
-            result = new Gdk.Pixbuf.from_file_at_scale(get_filepath(), scaled.width,
-                scaled.height, false);
-        }
-
-        return result;
-    }
 }
 
 public class GifMetadataWriter : PhotoFileMetadataWriter {
diff --git a/src/photos/HeifSupport.vala b/src/photos/HeifSupport.vala
new file mode 100644
index 0000000..0c05e02
--- /dev/null
+++ b/src/photos/HeifSupport.vala
@@ -0,0 +1,150 @@
+/* Copyright 2016 Software Freedom Conservancy Inc.
+ *
+ * This software is licensed under the GNU LGPL (version 2.1 or later).
+ * See the COPYING file in this distribution.
+ */
+
+class HeifFileFormatProperties : PhotoFileFormatProperties {
+    private static string[] KNOWN_EXTENSIONS = { "heif", "heic" };
+    private static string[] KNOWN_MIME_TYPES = { "image/heif" };
+
+    private static HeifFileFormatProperties instance = null;
+
+    public static void init() {
+        instance = new HeifFileFormatProperties();
+    }
+    
+    public static HeifFileFormatProperties get_instance() {
+        return instance;
+    }
+    
+    public override PhotoFileFormat get_file_format() {
+        return PhotoFileFormat.HEIF;
+    }
+    
+    public override PhotoFileFormatFlags get_flags() {
+        return PhotoFileFormatFlags.NONE;
+    }
+
+    public override string get_user_visible_name() {
+        return _("HEIF");
+    }
+
+    public override string get_default_extension() {
+        return KNOWN_EXTENSIONS[0];
+    }
+    
+    public override string[] get_known_extensions() {
+        return KNOWN_EXTENSIONS;
+    }
+    
+    public override string get_default_mime_type() {
+        return KNOWN_MIME_TYPES[0];
+    }
+    
+    public override string[] get_mime_types() {
+        return KNOWN_MIME_TYPES;
+    }
+}
+
+public class HeifSniffer : GdkSniffer {
+    private const string[] MAGIC_SEQUENCES = { "heic", "heix", "hevc", "heim", "heis", "hevm", "hevs", "mif1", "msf1"};
+
+    public HeifSniffer(File file, PhotoFileSniffer.Options options) {
+        base (file, options);
+    }
+
+    public override DetectedPhotoInformation? sniff(out bool is_corrupted) throws Error {
+        // Rely on GdkSniffer to detect corruption
+        is_corrupted = false;
+        
+        if (!is_supported_bmff_with_variants(file, MAGIC_SEQUENCES))
+            return null;
+        
+        DetectedPhotoInformation? detected = base.sniff(out is_corrupted);
+        if (detected == null)
+            return null;
+
+        if (detected.file_format == PhotoFileFormat.AVIF)
+            detected.file_format = PhotoFileFormat.HEIF;
+
+        // Heif contains its own rotation information, so we need to ignore the EXIF rotation+
+        if (detected.metadata != null) {
+            detected.metadata.set_orientation(Orientation.TOP_LEFT);
+        }
+
+        return (detected.file_format == PhotoFileFormat.HEIF) ? detected : null;
+    }
+
+}
+
+public class HeifReader : GdkReader {
+    public HeifReader(string filepath) {
+        base (filepath, PhotoFileFormat.HEIF);
+    }
+
+    public override PhotoMetadata read_metadata() throws Error {
+        PhotoMetadata metadata = new PhotoMetadata();
+        metadata.read_from_file(get_file());
+        // Heif contains its own rotation information, so we need to ignore the EXIF rotation
+        metadata.set_orientation(Orientation.TOP_LEFT);
+        return metadata;
+    }
+
+}
+
+public class HeifMetadataWriter : PhotoFileMetadataWriter {
+    public HeifMetadataWriter(string filepath) {
+        base (filepath, PhotoFileFormat.HEIF);
+    }
+    
+    public override void write_metadata(PhotoMetadata metadata) throws Error {
+        metadata.write_to_file(get_file());
+    }
+}
+
+public class HeifFileFormatDriver : PhotoFileFormatDriver {
+    private static HeifFileFormatDriver instance = null;
+    
+    public static void init() {
+        instance = new HeifFileFormatDriver();
+        HeifFileFormatProperties.init();
+    }
+    
+    public static HeifFileFormatDriver get_instance() {
+        return instance;
+    }
+    
+    public override PhotoFileFormatProperties get_properties() {
+        return HeifFileFormatProperties.get_instance();
+    }
+    
+    public override PhotoFileReader create_reader(string filepath) {
+        return new HeifReader(filepath);
+    }
+    
+    public override bool can_write_image() {
+        return false;
+    }
+    
+    public override bool can_write_metadata() {
+        return true;
+    }
+    
+    public override PhotoFileWriter? create_writer(string filepath) {
+        return null;
+    }
+    
+    public override PhotoFileMetadataWriter? create_metadata_writer(string filepath) {
+        return new HeifMetadataWriter(filepath);
+    }
+    
+    public override PhotoFileSniffer create_sniffer(File file, PhotoFileSniffer.Options options) {
+        return new HeifSniffer(file, options);
+    }
+    
+    public override PhotoMetadata create_metadata() {
+        return new PhotoMetadata();
+    }
+}
+
diff --git a/src/photos/JfifSupport.vala b/src/photos/JfifSupport.vala
index 5ea64a5..0de45f8 100644
--- a/src/photos/JfifSupport.vala
+++ b/src/photos/JfifSupport.vala
@@ -103,17 +103,78 @@ public class JfifSniffer : GdkSniffer {
     }
     
     public override DetectedPhotoInformation? sniff(out bool is_corrupted) throws Error {
-        // Rely on GdkSniffer to detect corruption
         is_corrupted = false;
-        
-        if (!Jpeg.is_jpeg(file))
-            return null;
-        
-        DetectedPhotoInformation? detected = base.sniff(out is_corrupted);
-        if (detected == null)
+        if (!calc_md5) {
+            return fast_sniff (out is_corrupted);
+        } else {
+            if (!Jpeg.is_jpeg(file)) {
+                return null;
+            }
+
+            // Rely on GdkSniffer to detect corruption
+
+            DetectedPhotoInformation? detected = base.sniff(out is_corrupted);
+            if (detected == null)
+                return null;
+
+            return (detected.file_format == PhotoFileFormat.JFIF) ? detected : null;
+        }
+    }
+
+    private DetectedPhotoInformation? fast_sniff(out bool is_corrupted) throws Error {
+        is_corrupted = false;
+        var detected = new DetectedPhotoInformation();
+
+        detected.metadata = new PhotoMetadata();
+        try {
+            detected.metadata.read_from_file(file);
+        } catch (Error err) {
+            // no metadata detected
+            detected.metadata = null;
+        }
+
+        var fins = file.read(null);
+        var dins = new DataInputStream(fins);
+        dins.set_byte_order(DataStreamByteOrder.BIG_ENDIAN);
+        var seekable = (Seekable) dins;
+
+        var marker = Jpeg.Marker.INVALID;
+        var length = Jpeg.read_marker_2(dins, out marker);
+
+        if (marker != Jpeg.Marker.SOI) {
             return null;
-        
-        return (detected.file_format == PhotoFileFormat.JFIF) ? detected : null;
+        }
+
+        length = Jpeg.read_marker_2(dins, out marker);
+        while (!marker.is_sof() && length > 0) {
+            seekable.seek(length, SeekType.CUR, null);
+            length = Jpeg.read_marker_2(dins, out marker);
+        }
+
+        if (marker.is_sof()) {
+            if (length < 6) {
+                is_corrupted = true;
+                return null;
+            }
+
+            // Skip precision
+            dins.read_byte();
+
+            // Next two 16 bytes are image dimensions
+            uint16 height = dins.read_uint16();
+            uint16 width = dins.read_uint16();
+
+            detected.image_dim = Dimensions(width, height);
+            detected.colorspace = Gdk.Colorspace.RGB;
+            detected.channels = 3;
+            detected.bits_per_channel = 8;
+            detected.format_name = "jpeg";
+            detected.file_format = PhotoFileFormat.from_pixbuf_name(detected.format_name);
+        } else {
+            is_corrupted = true;
+        }
+
+        return detected;
     }
 }
 
@@ -159,6 +220,16 @@ namespace Jpeg {
         public uint8 get_byte() {
             return (uint8) this;
         }
+
+        public bool is_sof() {
+            // FFCn is SOF unless n is a multiple of 4 > 0 (FFC4, FFC8, FFCC)
+            if ((this & 0xC0) != 0xC0) {
+                return false;
+            }
+
+            var variant = this & 0x0F;
+            return variant == 0 || variant % 4 != 0;
+        }
     }
     
     public enum Quality {
@@ -219,12 +290,9 @@ namespace Jpeg {
         return is_jpeg_stream(mins);
     }
 
-    private int read_marker(InputStream fins, out Jpeg.Marker marker) throws Error {
+    private int32 read_marker_2(DataInputStream dins, out Jpeg.Marker marker) throws Error {
         marker = Jpeg.Marker.INVALID;
-        
-        DataInputStream dins = new DataInputStream(fins);
-        dins.set_byte_order(DataStreamByteOrder.BIG_ENDIAN);
-        
+
         if (dins.read_byte() != Jpeg.MARKER_PREFIX)
             return -1;
         
@@ -235,9 +303,10 @@ namespace Jpeg {
         }
         
         uint16 length = dins.read_uint16();
-        if (length < 2 && fins is Seekable) {
+        var seekable = dins as Seekable;
+        if (length < 2 && dins != null) {
             debug("Invalid length %Xh at ofs %" + int64.FORMAT + "Xh", length,
-                    (fins as Seekable).tell() - 2);
+                    seekable.tell() - 2);
             
             return -1;
         }
@@ -245,5 +314,12 @@ namespace Jpeg {
         // account for two length bytes already read
         return length - 2;
     }
+
+    private int read_marker(InputStream fins, out Jpeg.Marker marker) throws Error {
+        DataInputStream dins = new DataInputStream(fins);
+        dins.set_byte_order(DataStreamByteOrder.BIG_ENDIAN);
+
+        return read_marker_2(dins, out marker);
+    }
 }
 
diff --git a/src/photos/JpegXLSupport.vala b/src/photos/JpegXLSupport.vala
new file mode 100644
index 0000000..eed220c
--- /dev/null
+++ b/src/photos/JpegXLSupport.vala
@@ -0,0 +1,149 @@
+/* Copyright 2016 Software Freedom Conservancy Inc.
+ *
+ * This software is licensed under the GNU LGPL (version 2.1 or later).
+ * See the COPYING file in this distribution.
+ */
+
+class JpegXLFileFormatProperties : PhotoFileFormatProperties {
+    private static string[] KNOWN_EXTENSIONS = { "jxl", "jpegxl" };
+    private static string[] KNOWN_MIME_TYPES = { "image/jxl" };
+
+    private static JpegXLFileFormatProperties instance = null;
+
+    public static void init() {
+        instance = new JpegXLFileFormatProperties();
+    }
+    
+    public static JpegXLFileFormatProperties get_instance() {
+        return instance;
+    }
+    
+    public override PhotoFileFormat get_file_format() {
+        return PhotoFileFormat.JPEGXL;
+    }
+    
+    public override PhotoFileFormatFlags get_flags() {
+        return PhotoFileFormatFlags.NONE;
+    }
+
+    public override string get_user_visible_name() {
+        return _("JPEGXL");
+    }
+
+    public override string get_default_extension() {
+        return KNOWN_EXTENSIONS[0];
+    }
+    
+    public override string[] get_known_extensions() {
+        return KNOWN_EXTENSIONS;
+    }
+    
+    public override string get_default_mime_type() {
+        return KNOWN_MIME_TYPES[0];
+    }
+    
+    public override string[] get_mime_types() {
+        return KNOWN_MIME_TYPES;
+    }
+}
+
+public class JpegXLSniffer : GdkSniffer {
+    // See https://github.com/ImageMagick/jpeg-xl/blob/main/doc/format_overview.md#file-format
+    private const uint8[] CODESTREAM_MAGIC_SEQUENCE = { 0xff, 0x0a };
+    private const uint8[] BMFF_MAGIC_SEQUENCE = {0x00, 0x00, 0x00, 0x0C, 0x4A, 0x58, 0x4C, 0x20, 0x0D, 0x0A, 0x87, 0x0A};
+
+
+    public JpegXLSniffer(File file, PhotoFileSniffer.Options options) {
+        base (file, options);
+    }
+
+    private static bool is_jpegxl_file(File file) throws Error {
+        FileInputStream instream = file.read(null);
+
+        // Read out first four bytes
+        uint8[] file_lead_sequence = new uint8[BMFF_MAGIC_SEQUENCE.length];
+
+        var size = instream.read(file_lead_sequence, null);
+
+        return size == BMFF_MAGIC_SEQUENCE.length && (Memory.cmp(CODESTREAM_MAGIC_SEQUENCE, file_lead_sequence, CODESTREAM_MAGIC_SEQUENCE.length) == 0 ||
+                Memory.cmp(BMFF_MAGIC_SEQUENCE, file_lead_sequence, BMFF_MAGIC_SEQUENCE.length) == 0);
+
+    }
+
+    public override DetectedPhotoInformation? sniff(out bool is_corrupted) throws Error {
+        // Rely on GdkSniffer to detect corruption
+        is_corrupted = false;
+        
+        if (!is_jpegxl_file(file))
+            return null;
+        
+        DetectedPhotoInformation? detected = base.sniff(out is_corrupted);
+        if (detected == null)
+            return null;
+
+        return (detected.file_format == PhotoFileFormat.JPEGXL) ? detected : null;
+    }
+
+}
+
+public class JpegXLReader : GdkReader {
+    public JpegXLReader(string filepath) {
+        base (filepath, PhotoFileFormat.JPEGXL);
+    }
+}
+
+public class JpegXLMetadataWriter : PhotoFileMetadataWriter {
+    public JpegXLMetadataWriter(string filepath) {
+        base (filepath, PhotoFileFormat.JPEGXL);
+    }
+    
+    public override void write_metadata(PhotoMetadata metadata) throws Error {
+        metadata.write_to_file(get_file());
+    }
+}
+
+public class JpegXLFileFormatDriver : PhotoFileFormatDriver {
+    private static JpegXLFileFormatDriver instance = null;
+    
+    public static void init() {
+        instance = new JpegXLFileFormatDriver();
+        JpegXLFileFormatProperties.init();
+    }
+    
+    public static JpegXLFileFormatDriver get_instance() {
+        return instance;
+    }
+    
+    public override PhotoFileFormatProperties get_properties() {
+        return JpegXLFileFormatProperties.get_instance();
+    }
+    
+    public override PhotoFileReader create_reader(string filepath) {
+        return new JpegXLReader(filepath);
+    }
+    
+    public override bool can_write_image() {
+        return false;
+    }
+    
+    public override bool can_write_metadata() {
+        return true;
+    }
+    
+    public override PhotoFileWriter? create_writer(string filepath) {
+        return null;
+    }
+    
+    public override PhotoFileMetadataWriter? create_metadata_writer(string filepath) {
+        return new JpegXLMetadataWriter(filepath);
+    }
+    
+    public override PhotoFileSniffer create_sniffer(File file, PhotoFileSniffer.Options options) {
+        return new JpegXLSniffer(file, options);
+    }
+    
+    public override PhotoMetadata create_metadata() {
+        return new PhotoMetadata();
+    }
+}
+
diff --git a/src/photos/PhotoFileFormat.vala b/src/photos/PhotoFileFormat.vala
index e642008..4c69de3 100644
--- a/src/photos/PhotoFileFormat.vala
+++ b/src/photos/PhotoFileFormat.vala
@@ -58,12 +58,16 @@ public enum PhotoFileFormat {
     TIFF,
     BMP,
     GIF,
+    WEBP,
+    AVIF,
+    HEIF,
+    JPEGXL,
     UNKNOWN;
     
     // This is currently listed in the order of detection, that is, the file is examined from
     // left to right.  (See PhotoFileInterrogator.)
     public static PhotoFileFormat[] get_supported() {
-        return { JFIF, RAW, PNG, TIFF, BMP, GIF };
+        return { JFIF, RAW, PNG, TIFF, BMP, GIF, WEBP, AVIF, HEIF, JPEGXL };
     }
     
     public static PhotoFileFormat[] get_writeable() {
@@ -141,7 +145,19 @@ public enum PhotoFileFormat {
 
             case GIF:
                 return 5;
-            
+
+            case WEBP:
+                return 6;
+
+            case AVIF:
+                return 7;
+
+            case HEIF:
+                return 8;
+
+            case JPEGXL:
+                return 9;
+
             case UNKNOWN:
             default:
                 return -1;
@@ -169,6 +185,18 @@ public enum PhotoFileFormat {
             case 5:
                 return GIF;
                             
+            case 6:
+                return WEBP;
+
+            case 7:
+                return AVIF;
+
+            case 8:
+                return HEIF;
+
+            case 9:
+                return JPEGXL;
+
             default:
                 return UNKNOWN;
         }
@@ -217,7 +245,17 @@ public enum PhotoFileFormat {
 
             case "gif":
                 return PhotoFileFormat.GIF;
-            
+
+            case "heif/avif":
+            case "avif":
+                return PhotoFileFormat.AVIF;
+
+            case "heif":
+                return PhotoFileFormat.HEIF;
+
+            case "jxl":
+                return PhotoFileFormat.JPEGXL;
+
             default:
                 return PhotoFileFormat.UNKNOWN;
         }
@@ -249,6 +287,22 @@ public enum PhotoFileFormat {
                 Photos.GifFileFormatDriver.init();
                 break;
 
+            case WEBP:
+                Photos.WebpFileFormatDriver.init();
+                break;
+
+            case AVIF:
+                AvifFileFormatDriver.init();
+                break;
+
+            case HEIF:
+                HeifFileFormatDriver.init();
+                break;
+
+            case JPEGXL:
+                JpegXLFileFormatDriver.init();
+                break;
+
             default:
                 error("Unsupported file format %s", this.to_string());
         }
@@ -274,6 +328,18 @@ public enum PhotoFileFormat {
             case GIF:
                 return Photos.GifFileFormatDriver.get_instance();
 
+            case WEBP:
+                return Photos.WebpFileFormatDriver.get_instance();
+
+            case AVIF:
+                return AvifFileFormatDriver.get_instance();
+
+            case HEIF:
+                return HeifFileFormatDriver.get_instance();
+
+            case JPEGXL:
+                return JpegXLFileFormatDriver.get_instance();
+
             default:
                 error("Unsupported file format %s", this.to_string());
         }
diff --git a/src/photos/PhotoFileSniffer.vala b/src/photos/PhotoFileSniffer.vala
index 7442fde..6358920 100644
--- a/src/photos/PhotoFileSniffer.vala
+++ b/src/photos/PhotoFileSniffer.vala
@@ -47,6 +47,34 @@ public abstract class PhotoFileSniffer {
     }
     
     public abstract DetectedPhotoInformation? sniff(out bool is_corrupted) throws Error;
+
+    protected static bool is_supported_bmff_with_variants(File file, string[] variants) throws Error {
+        
+        FileInputStream instream = file.read(null);
+
+        // Skip the first four bytes
+        if (instream.skip(4) != 4) {
+            return false;
+        }
+
+        // The next four bytes need to be ftyp
+        var buf = new uint8[4];
+        if (instream.read(buf, null) != 4) {
+            return false;
+        }
+
+        if (Memory.cmp("ftyp".data, buf, 4) != 0) {
+            return false;
+        }
+
+        if (instream.read(buf, null) != 4) {
+            return false;
+        }
+
+        buf += '\0';
+
+        return (string)buf in variants;
+    }
 }
 
 //
diff --git a/src/photos/PhotoMetadata.vala b/src/photos/PhotoMetadata.vala
index a9b7457..3bf77d6 100644
--- a/src/photos/PhotoMetadata.vala
+++ b/src/photos/PhotoMetadata.vala
@@ -241,9 +241,13 @@ public class PhotoMetadata : MediaMetadata {
         public override Bytes flatten() throws Error {
             unowned GExiv2.PreviewProperties?[] props = owner.exiv2.get_preview_properties();
             assert(props != null && props.length > number);
-            
-            return new
-                Bytes(owner.exiv2.get_preview_image(props[number]).get_data());
+           
+            try {
+                return new
+                    Bytes(owner.exiv2.try_get_preview_image(props[number]).get_data());
+            } catch (Error err) {
+                return new Bytes(null);
+            }
         }
     }
     
@@ -278,12 +282,8 @@ public class PhotoMetadata : MediaMetadata {
         exiv2 = new GExiv2.Metadata();
         exif = null;
         
-#if NEW_GEXIV2_API
         exiv2.open_buf(buffer[0:length]);
-#else
-        exiv2.open_buf(buffer, length);
-#endif
-        exif = Exif.Data.new_from_data(buffer);
+        exif = Exif.Data.new_from_data(buffer[0:length]);
         source_name = "<memory buffer %d bytes>".printf(length);
     }
     
@@ -291,11 +291,8 @@ public class PhotoMetadata : MediaMetadata {
         exiv2 = new GExiv2.Metadata();
         exif = null;
         
-#if NEW_GEXIV2_API
         exiv2.from_app1_segment(buffer.get_data());
-#else
         exif = Exif.Data.new_from_data(buffer.get_data());
-#endif
         source_name = "<app1 segment %zu bytes>".printf(buffer.get_size());
     }
     
@@ -371,7 +368,11 @@ public class PhotoMetadata : MediaMetadata {
     }
     
     public bool has_tag(string tag) {
-        return exiv2.has_tag(tag);
+        try {
+            return exiv2.try_has_tag(tag);
+        } catch (Error error) {
+            return false;
+        }
     }
     
     private Gee.Set<string> create_string_set(owned CompareDataFunc<string>? compare_func) {
@@ -397,6 +398,9 @@ public class PhotoMetadata : MediaMetadata {
             case MetadataDomain.IPTC:
                 tags = exiv2.get_iptc_tags();
             break;
+            default:
+            // Just ignore any other unknown tags
+            break;
         }
         
         if (tags == null || tags.length == 0)
@@ -429,19 +433,35 @@ public class PhotoMetadata : MediaMetadata {
     }
     
     public string? get_tag_label(string tag) {
-        return GExiv2.Metadata.get_tag_label(tag);
+        try {
+            return GExiv2.Metadata.try_get_tag_label(tag);
+        } catch (Error error) {
+            return null;
+        }
     }
     
     public string? get_tag_description(string tag) {
-        return GExiv2.Metadata.get_tag_description(tag);
+        try {
+            return GExiv2.Metadata.try_get_tag_description(tag);
+        } catch (Error error) {
+            return null;
+        }
     }
     
     public string? get_string(string tag, PrepareInputTextOptions options = PREPARE_STRING_OPTIONS) {
-        return prepare_input_text(exiv2.get_tag_string(tag), options, DEFAULT_USER_TEXT_INPUT_LENGTH);
+        try {
+            return prepare_input_text(exiv2.try_get_tag_string(tag), options, DEFAULT_USER_TEXT_INPUT_LENGTH);
+        } catch (Error error) {
+            return null;
+        }
     }
     
     public string? get_string_interpreted(string tag, PrepareInputTextOptions options = PREPARE_STRING_OPTIONS) {
-        return prepare_input_text(exiv2.get_tag_interpreted_string(tag), options, DEFAULT_USER_TEXT_INPUT_LENGTH);
+        try {
+            return prepare_input_text(exiv2.try_get_tag_interpreted_string(tag), options, DEFAULT_USER_TEXT_INPUT_LENGTH);
+        } catch (Error error) {
+            return null;
+        }
     }
     
     public string? get_first_string(string[] tags) {
@@ -469,26 +489,30 @@ public class PhotoMetadata : MediaMetadata {
     // NOTE: get_tag_multiple() in gexiv2 currently does not work with EXIF tags (as EXIF can 
     // never return a list of strings).  It will quietly return NULL if attempted.  Until fixed
     // (there or here), don't use this function to access EXIF.  See:
-    // http://trac.yorba.org/ticket/2966
+    // https://gitlab.gnome.org/GNOME/gexiv2/issues/10
     public Gee.List<string>? get_string_multiple(string tag) {
-        string[] values = exiv2.get_tag_multiple(tag);
-        if (values == null || values.length == 0)
-            return null;
-        
-        Gee.List<string> list = new Gee.ArrayList<string>();
-        
-        Gee.HashSet<string> collection = new Gee.HashSet<string>();
-        foreach (string value in values) {
-            string? prepped = prepare_input_text(value, PREPARE_STRING_OPTIONS,
-                DEFAULT_USER_TEXT_INPUT_LENGTH);
-                
-            if (prepped != null && !collection.contains(prepped)) {
-                list.add(prepped);
-                collection.add(prepped);
+        try {
+            string[] values = exiv2.try_get_tag_multiple(tag);
+            if (values == null || values.length == 0)
+                return null;
+            
+            Gee.List<string> list = new Gee.ArrayList<string>();
+            
+            Gee.HashSet<string> collection = new Gee.HashSet<string>();
+            foreach (string value in values) {
+                string? prepped = prepare_input_text(value, PREPARE_STRING_OPTIONS,
+                    DEFAULT_USER_TEXT_INPUT_LENGTH);
+                    
+                if (prepped != null && !collection.contains(prepped)) {
+                    list.add(prepped);
+                    collection.add(prepped);
+                }
             }
+            
+            return list.size > 0 ? list : null;
+        } catch (Error error) {
+            return null;
         }
-        
-        return list.size > 0 ? list : null;
     }
     
     // Returns a List that has been filtered through a Set, so no duplicates will be found.
@@ -496,7 +520,7 @@ public class PhotoMetadata : MediaMetadata {
     // NOTE: get_tag_multiple() in gexiv2 currently does not work with EXIF tags (as EXIF can 
     // never return a list of strings).  It will quietly return NULL if attempted.  Until fixed
     // (there or here), don't use this function to access EXIF.  See:
-    // http://trac.yorba.org/ticket/2966
+    // https://gitlab.gnome.org/GNOME/gexiv2/issues/10
     public Gee.List<string>? get_first_string_multiple(string[] tags) {
         foreach (string tag in tags) {
             Gee.List<string>? values = get_string_multiple(tag);
@@ -507,16 +531,20 @@ public class PhotoMetadata : MediaMetadata {
         return null;
     }
     
-    public void set_string(string tag, string value, PrepareInputTextOptions options = PREPARE_STRING_OPTIONS) {
-        string? prepped = prepare_input_text(value, options, DEFAULT_USER_TEXT_INPUT_LENGTH);
+    public void set_string(string tag, string value, PrepareInputTextOptions options = PREPARE_STRING_OPTIONS,
+                           int length = DEFAULT_USER_TEXT_INPUT_LENGTH) {
+        string? prepped = prepare_input_text(value, options, length);
         if (prepped == null) {
             warning("Not setting tag %s to string %s: invalid UTF-8", tag, value);
             
             return;
         }
         
-        if (!exiv2.set_tag_string(tag, prepped))
-            warning("Unable to set tag %s to string %s from source %s", tag, value, source_name);
+        try {
+            exiv2.try_set_tag_string(tag, prepped);
+        } catch (Error error) {
+            warning("Unable to set tag %s to string %s from source %s: %s", tag, value, source_name, error.message);
+        }
     }
     
     private delegate void SetGenericValue(string tag);
@@ -562,13 +590,16 @@ public class PhotoMetadata : MediaMetadata {
             return;
 
         // append a null pointer to the end of the string array -- this is a necessary
-        // workaround for http://trac.yorba.org/ticket/3264. See also
-        // http://trac.yorba.org/ticket/3257, which describes the user-visible behavior
-        // seen in the Flickr Connector as a result of the former bug.
+        // workaround for https://bugzilla.gnome.org/show_bug.cgi?id=712479. See also
+        // https://bugzilla.gnome.org/show_bug.cgi?id=717438, which describes the
+        // user-visible behavior seen in the Flickr Connector as a result of the former bug.
         values += null;
         
-        if (!exiv2.set_tag_multiple(tag, values))
-            warning("Unable to set %d strings to tag %s from source %s", values.length, tag, source_name);
+        try {
+            exiv2.try_set_tag_multiple(tag, values);
+        } catch (Error err) {
+            warning("Unable to set %d strings to tag %s from source %s: %s", values.length, tag, source_name, err.message);
+        }
     }
     
     public void set_all_string_multiple(string[] tags, Gee.Collection<string> values, SetOption option) {
@@ -576,13 +607,16 @@ public class PhotoMetadata : MediaMetadata {
     }
     
     public bool get_long(string tag, out long value) {
+        value = 0;
         if (!has_tag(tag)) {
-            value = 0;
-            
             return false;
         }
         
-        value = exiv2.get_tag_long(tag);
+        try {
+            value = exiv2.try_get_tag_long(tag);
+        } catch (Error error) {
+            return false;
+        }
         
         return true;
     }
@@ -599,8 +633,11 @@ public class PhotoMetadata : MediaMetadata {
     }
     
     public void set_long(string tag, long value) {
-        if (!exiv2.set_tag_long(tag, value))
-            warning("Unable to set tag %s to long %ld from source %s", tag, value, source_name);
+        try {
+            exiv2.try_set_tag_long(tag, value);
+        } catch (Error err) {
+            warning("Unable to set tag %s to long %ld from source %s: %s", tag, value, source_name, err.message);
+        }
     }
     
     public void set_all_long(string[] tags, long value, SetOption option) {
@@ -609,11 +646,19 @@ public class PhotoMetadata : MediaMetadata {
     
     public bool get_rational(string tag, out MetadataRational rational) {
         int numerator, denominator;
-        bool result = exiv2.get_exif_tag_rational(tag, out numerator, out denominator);
-        
-        rational = MetadataRational(numerator, denominator);
-        
-        return result;
+        try {
+            if (exiv2.try_get_exif_tag_rational(tag, out numerator, out denominator)) {
+                rational = MetadataRational(numerator, denominator);
+            } else {
+                rational = MetadataRational.invalid();
+                return false;
+            }
+        } catch (Error error) {
+            rational = MetadataRational.invalid();
+            return false;
+        }
+
+        return true;
     }
     
     public bool get_first_rational(string[] tags, out MetadataRational rational) {
@@ -628,9 +673,11 @@ public class PhotoMetadata : MediaMetadata {
     }
     
     public void set_rational(string tag, MetadataRational rational) {
-        if (!exiv2.set_exif_tag_rational(tag, rational.numerator, rational.denominator)) {
-            warning("Unable to set tag %s to rational %s from source %s", tag, rational.to_string(),
-                source_name);
+        try {
+            exiv2.try_set_exif_tag_rational(tag, rational.numerator, rational.denominator);
+        } catch (Error err) {
+            warning("Unable to set tag %s to rational %s from source %s: %s", tag, rational.to_string(),
+                source_name, err.message);
         }
     }
     
@@ -769,7 +816,10 @@ public class PhotoMetadata : MediaMetadata {
     }
     
     public void remove_exif_thumbnail() {
-        exiv2.erase_exif_thumbnail();
+        try {
+            exiv2.try_erase_exif_thumbnail();
+        } catch (Error err) { }
+
         if (exif != null) {
             Exif.Mem.new_default().free(exif.data);
             exif.data = null;
@@ -778,7 +828,9 @@ public class PhotoMetadata : MediaMetadata {
     }
     
     public void remove_tag(string tag) {
-        exiv2.clear_tag(tag);
+        try {
+            exiv2.try_clear_tag(tag);
+        } catch (Error err){}
     }
     
     public void remove_tags(string[] tags) {
@@ -799,6 +851,9 @@ public class PhotoMetadata : MediaMetadata {
             case MetadataDomain.IPTC:
                 exiv2.clear_iptc();
             break;
+            default:
+                // Just ignore any unknown tags
+            break;
         }
     }
     
@@ -881,7 +936,7 @@ public class PhotoMetadata : MediaMetadata {
     public static string[] HEIGHT_TAGS = {
         "Exif.Photo.PixelYDimension",
         "Xmp.exif.PixelYDimension",
-        "Xmp.tiff.ImageHeight",
+        "Xmp.tiff.ImageLength",
         "Xmp.exif.PixelYDimension"
     };
     
@@ -923,7 +978,7 @@ public class PhotoMetadata : MediaMetadata {
     // (sometimes) appropriate tag for the description.  And there's general confusion about
     // whether Exif.Image.ImageDescription is a description (which is what the tag name
     // suggests) or a title (which is what the specification states).
-    // See: http://trac.yorba.org/wiki/PhotoTags
+    // See: https://wiki.gnome.org/Apps/Shotwell/PhotoTags
     //
     // Hence, the following logic tries to do the right thing in most of these cases.  If
     // the iPhoto title tag is detected, it and the iPhoto description tag are used.  Otherwise,
@@ -997,8 +1052,9 @@ public class PhotoMetadata : MediaMetadata {
          * newlines from comments */
         if (!is_string_empty(comment))
             set_all_generic(COMMENT_TAGS, option, (tag) => {
+                // 4095 is coming from acdsee.notes which is limited to that
                 set_string(tag, comment, PREPARE_STRING_OPTIONS &
-                        ~PrepareInputTextOptions.STRIP_CRLF);
+                        ~PrepareInputTextOptions.STRIP_CRLF, 4095);
             });
         else
             remove_tags(COMMENT_TAGS);
@@ -1139,24 +1195,37 @@ public class PhotoMetadata : MediaMetadata {
     }
     
     public bool has_orientation() {
-        return exiv2.get_orientation() == GExiv2.Orientation.UNSPECIFIED;
+        try {
+            return exiv2.try_get_orientation() == GExiv2.Orientation.UNSPECIFIED;
+        } catch (Error err) {
+            debug("Failed to get orientation: %s", err.message);
+            return false;
+        }
     }
     
     // If not present, returns Orientation.TOP_LEFT.
     public Orientation get_orientation() {
         // GExiv2.Orientation is the same value-wise as Orientation, with one exception:
         // GExiv2.Orientation.UNSPECIFIED must be handled
-        GExiv2.Orientation orientation = exiv2.get_orientation();
-        if (orientation ==  GExiv2.Orientation.UNSPECIFIED || orientation < Orientation.MIN ||
-            orientation > Orientation.MAX)
+        try {
+            GExiv2.Orientation orientation = exiv2.try_get_orientation();
+            if (orientation ==  GExiv2.Orientation.UNSPECIFIED || orientation < Orientation.MIN ||
+                orientation > Orientation.MAX)
+                return Orientation.TOP_LEFT;
+            else
+                return (Orientation) orientation;
+        } catch (Error error) {
             return Orientation.TOP_LEFT;
-        else
-            return (Orientation) orientation;
+        }
     }
     
     public void set_orientation(Orientation orientation) {
         // GExiv2.Orientation is the same value-wise as Orientation
-        exiv2.set_orientation((GExiv2.Orientation) orientation);
+        try {
+            exiv2.try_set_orientation((GExiv2.Orientation) orientation);
+        } catch (Error err) {
+            debug("Failed to set the orientation: %s", err.message);
+        }
     }
     
     public bool get_gps(out double longitude, out string long_ref, out double latitude, out string lat_ref,
@@ -1164,14 +1233,22 @@ public class PhotoMetadata : MediaMetadata {
         longitude = 0.0;
         latitude = 0.0;
         altitude = 0.0;
-        if (!exiv2.get_gps_longitude(out longitude) || !exiv2.get_gps_latitude(out latitude)) {
-            long_ref = null;
-            lat_ref = null;
-            
-            return false;
+        try {
+            if (!exiv2.try_get_gps_longitude(out longitude) || !exiv2.try_get_gps_latitude(out latitude)) {
+                long_ref = null;
+                lat_ref = null;
+                
+                return false;
+            }
+        } catch (Error err) {
+            debug("Failed to get GPS lon/lat: %s", err.message);
         }
 
-        exiv2.get_gps_altitude(out altitude);
+        try {
+            exiv2.try_get_gps_altitude(out altitude);
+        } catch (Error err) {
+            debug("Failed to get GPS altitude: %s", err.message);
+        }
         
         long_ref = get_string("Exif.GPSInfo.GPSLongitudeRef");
         lat_ref = get_string("Exif.GPSInfo.GPSLatitudeRef");
@@ -1179,6 +1256,37 @@ public class PhotoMetadata : MediaMetadata {
         return true;
     }
 
+    public GpsCoords get_gps_coords() {
+        GpsCoords gps_coords = GpsCoords();
+        try {
+            double altitude;
+            gps_coords.has_gps = exiv2.try_get_gps_info(out gps_coords.longitude, out gps_coords.latitude, out altitude) ? 1 : 0;
+            if (gps_coords.has_gps > 0) {
+                if (get_string("Exif.GPSInfo.GPSLongitudeRef") == "W" && gps_coords.longitude > 0)
+                    gps_coords.longitude = -gps_coords.longitude;
+                if (get_string("Exif.GPSInfo.GPSLatitudeRef") == "S" && gps_coords.latitude > 0)
+                    gps_coords.latitude = -gps_coords.latitude;
+            }
+        } catch (Error err) {
+            gps_coords.has_gps = 0;
+        }
+
+        return gps_coords;
+    }
+
+    public void set_gps_coords(GpsCoords gps_coords) {
+        try {
+            if (gps_coords.has_gps > 0) {
+                var altitude = 0.0;
+                exiv2.try_get_gps_altitude(out altitude);
+                exiv2.try_set_gps_info(gps_coords.longitude, gps_coords.latitude, altitude);
+            } else
+                exiv2.try_delete_gps_info();
+        } catch (Error err) {
+            debug("Failed to set or remove GPS info: %s", err.message);
+        }
+    }
+
     public bool get_exposure(out MetadataRational exposure) {
         return get_rational("Exif.Photo.ExposureTime", out exposure);
     }
@@ -1326,7 +1434,7 @@ public class PhotoMetadata : MediaMetadata {
     // Other photo managers, notably F-Spot, take hints from Urgency fields about what the rating
     // of an imported photo should be, and we have decided to do as well. Xmp.xmp.Rating is the only 
     // field we've seen photo manages export ratings to, while Urgency fields seem to have a fundamentally
-    // different meaning. See http://trac.yorba.org/wiki/PhotoTags#Rating for more information.
+    // different meaning. See https://wiki.gnome.org/Apps/Shotwell/PhotoTags#Rating for more information.
     public void set_rating(Rating rating) {
         int int_rating = rating.serialize();
         set_string("Xmp.xmp.Rating", int_rating.to_string());
diff --git a/src/photos/PngSupport.vala b/src/photos/PngSupport.vala
index c891136..e154fc4 100644
--- a/src/photos/PngSupport.vala
+++ b/src/photos/PngSupport.vala
@@ -88,33 +88,6 @@ public class PngReader : GdkReader {
     public PngReader(string filepath) {
         base (filepath, PhotoFileFormat.PNG);
     }
-    
-    public override Gdk.Pixbuf scaled_read(Dimensions full, Dimensions scaled) throws Error {
-        Gdk.Pixbuf result = null;
-        /* if we encounter a situation where there are two orders of magnitude or more of
-           difference between the full image size and the scaled size, and if the full image
-           size has five or more decimal digits of precision, Gdk.Pixbuf.from_file_at_scale( ) can
-           fail due to what appear to be floating-point round-off issues. This isn't surprising,
-           since 32-bit floats only have 6-7 decimal digits of precision in their mantissa. In
-           this case, we prefetch the image at a larger scale and then downsample it to the
-           desired scale as a post-process step. This short-circuits Gdk.Pixbuf's buggy
-           scaling code. */
-        if (((full.width > 9999) || (full.height > 9999)) && ((scaled.width < 100) ||
-             (scaled.height < 100))) {
-            Dimensions prefetch_dimensions = full.get_scaled_by_constraint(1000,
-                ScaleConstraint.DIMENSIONS);
-                                  
-            result = new Gdk.Pixbuf.from_file_at_scale(get_filepath(), prefetch_dimensions.width,
-                prefetch_dimensions.height, false);
-
-            result = result.scale_simple(scaled.width, scaled.height, Gdk.InterpType.HYPER);
-        } else {
-            result = new Gdk.Pixbuf.from_file_at_scale(get_filepath(), scaled.width,
-                scaled.height, false);
-        }
-
-        return result;
-    }
 }
 
 public class PngWriter : PhotoFileWriter {
diff --git a/src/photos/RawSupport.vala b/src/photos/RawSupport.vala
index 8c23826..538c949 100644
--- a/src/photos/RawSupport.vala
+++ b/src/photos/RawSupport.vala
@@ -51,7 +51,7 @@ public class RawFileFormatDriver : PhotoFileFormatDriver {
 
 public class RawFileFormatProperties : PhotoFileFormatProperties {
     private static string[] KNOWN_EXTENSIONS = {
-        "3fr", "arw", "srf", "sr2", "bay", "crw", "cr2", "cap", "iiq", "eip", "dcs", "dcr", "drf",
+        "3fr", "arw", "srf", "sr2", "bay", "crw", "cr2", "cr3", "cap", "iiq", "eip", "dcs", "dcr", "drf",
         "k25", "kdc", "dng", "erf", "fff", "mef", "mos", "mrw", "nef", "nrw", "orf", "ptx", "pef",
         "pxn", "r3d", "raf", "raw", "rw2", "raw", "rwl", "rwz", "x3f", "srw"
     };
@@ -63,6 +63,7 @@ public class RawFileFormatProperties : PhotoFileFormatProperties {
     
         /* manufacturer blessed MIME types */
         "image/x-canon-cr2",
+        "image/x-canon-cr3",
         "image/x-canon-crw",
         "image/x-fuji-raf",
         "image/x-adobe-dng",
@@ -85,6 +86,7 @@ public class RawFileFormatProperties : PhotoFileFormatProperties {
         "image/x-bay",
         "image/x-crw",
         "image/x-cr2",
+        "image/x-cr3",
         "image/x-cap",
         "image/x-iiq",
         "image/x-eip",
@@ -174,7 +176,6 @@ public class RawSniffer : PhotoFileSniffer {
         
         try {
             processor.open_file(file.get_path());
-            processor.unpack();
             processor.adjust_sizes_info_only();
         } catch (GRaw.Exception exception) {
             if (exception is GRaw.Exception.UNSUPPORTED_FILE)
@@ -195,7 +196,7 @@ public class RawSniffer : PhotoFileSniffer {
             // ignored
         }
         
-        if (detected.metadata != null) {
+        if (calc_md5 && detected.metadata != null) {
             detected.exif_md5 = detected.metadata.exif_hash();
             detected.thumbnail_md5 = detected.metadata.thumbnail_hash();
         }
@@ -211,15 +212,19 @@ public class RawSniffer : PhotoFileSniffer {
 }
 
 public class RawReader : PhotoFileReader {
+    private PhotoMetadata? cached_metadata = null;
+
     public RawReader(string filepath) {
         base (filepath, PhotoFileFormat.RAW);
     }
     
     public override PhotoMetadata read_metadata() throws Error {
-        PhotoMetadata metadata = new PhotoMetadata();
-        metadata.read_from_file(get_file());
-        
-        return metadata;
+        if (cached_metadata == null) {
+            PhotoMetadata metadata = new PhotoMetadata();
+            metadata.read_from_file(get_file());
+            cached_metadata = metadata;
+        }
+        return cached_metadata;
     }
     
     public override Gdk.Pixbuf unscaled_read() throws Error {
diff --git a/src/photos/TiffSupport.vala b/src/photos/TiffSupport.vala
index 7ed8b98..cadcd0e 100644
--- a/src/photos/TiffSupport.vala
+++ b/src/photos/TiffSupport.vala
@@ -151,6 +151,9 @@ private class TiffMetadataWriter : PhotoFileMetadataWriter {
     }
 }
 
+private const uint16 FILE_MARKER_TIFF = 42;
+private const uint16 FILE_MARKER_BIGTIFF = 43;
+
 public bool is_tiff(File file, Cancellable? cancellable = null) throws Error {
     DataInputStream dins = new DataInputStream(file.read());
     
@@ -173,8 +176,9 @@ public bool is_tiff(File file, Cancellable? cancellable = null) throws Error {
     
     // second two bytes: some random number
     uint16 lue = dins.read_uint16(cancellable);
-    if (lue != 42)
+    if (lue != FILE_MARKER_TIFF && lue != FILE_MARKER_BIGTIFF) {
         return false;
+    }
     
     // remaining bytes are offset of first IFD, which doesn't matter for our purposes
     return true;
diff --git a/src/photos/WebPSupport.vala b/src/photos/WebPSupport.vala
new file mode 100644
index 0000000..2f4723c
--- /dev/null
+++ b/src/photos/WebPSupport.vala
@@ -0,0 +1,240 @@
+/* Copyright 2016 Software Freedom Conservancy Inc.
+ *
+ * This software is licensed under the GNU LGPL (version 2.1 or later).
+ * See the COPYING file in this distribution.
+ */
+
+namespace Photos {
+
+public class WebpFileFormatDriver : PhotoFileFormatDriver {
+    private static WebpFileFormatDriver instance = null;
+
+    public static void init() {
+        instance = new WebpFileFormatDriver();
+        WebpFileFormatProperties.init();
+    }
+
+    public static WebpFileFormatDriver get_instance() {
+        return instance;
+    }
+
+    public override PhotoFileFormatProperties get_properties() {
+        return WebpFileFormatProperties.get_instance();
+    }
+
+    public override PhotoFileReader create_reader(string filepath) {
+        return new WebpReader(filepath);
+    }
+
+    public override PhotoMetadata create_metadata() {
+        return new PhotoMetadata();
+    }
+
+    public override bool can_write_image() {
+        return false;
+    }
+
+    public override bool can_write_metadata() {
+        return true;
+    }
+
+    public override PhotoFileWriter? create_writer(string filepath) {
+        return null;
+    }
+
+    public override PhotoFileMetadataWriter? create_metadata_writer(string filepath) {
+        return new WebpMetadataWriter(filepath);
+    }
+
+    public override PhotoFileSniffer create_sniffer(File file, PhotoFileSniffer.Options options) {
+        return new WebpSniffer(file, options);
+    }
+}
+
+private class WebpFileFormatProperties : PhotoFileFormatProperties {
+    private static string[] KNOWN_EXTENSIONS = {
+        "webp"
+    };
+
+    private static string[] KNOWN_MIME_TYPES = {
+        "image/webp"
+    };
+
+    private static WebpFileFormatProperties instance = null;
+
+    public static void init() {
+        instance = new WebpFileFormatProperties();
+    }
+
+    public static WebpFileFormatProperties get_instance() {
+        return instance;
+    }
+
+    public override PhotoFileFormat get_file_format() {
+        return PhotoFileFormat.WEBP;
+    }
+
+    public override PhotoFileFormatFlags get_flags() {
+        return PhotoFileFormatFlags.NONE;
+    }
+
+    public override string get_default_extension() {
+        return "webp";
+    }
+
+    public override string get_user_visible_name() {
+        return _("WebP");
+    }
+
+    public override string[] get_known_extensions() {
+        return KNOWN_EXTENSIONS;
+    }
+
+    public override string get_default_mime_type() {
+        return KNOWN_MIME_TYPES[0];
+    }
+
+    public override string[] get_mime_types() {
+        return KNOWN_MIME_TYPES;
+    }
+}
+
+private class WebpSniffer : PhotoFileSniffer {
+    private DetectedPhotoInformation detected = null;
+
+    public WebpSniffer(File file, PhotoFileSniffer.Options options) {
+        base (file, options);
+        detected = new DetectedPhotoInformation();
+    }
+
+    public override DetectedPhotoInformation? sniff(out bool is_corrupted) throws Error {
+        is_corrupted = false;
+
+        if (!is_webp(file))
+            return null;
+
+         // valac chokes on the ternary operator here
+        Checksum? md5_checksum = null;
+        if (calc_md5)
+            md5_checksum = new Checksum(ChecksumType.MD5);
+
+        detected.metadata = new PhotoMetadata();
+        try {
+            detected.metadata.read_from_file(file);
+        } catch (Error err) {
+            debug("Failed to load meta-data from file: %s", err.message);
+            // no metadata detected
+            detected.metadata = null;
+        }
+
+        if (calc_md5 && detected.metadata != null) {
+            detected.exif_md5 = detected.metadata.exif_hash();
+            detected.thumbnail_md5 = detected.metadata.thumbnail_hash();
+        }
+
+        // if no MD5, don't read as much, as the needed info will probably be gleaned
+        // in the first 8K to 16K
+        uint8[] buffer = calc_md5 ? new uint8[64 * 1024] : new uint8[8 * 1024];
+        size_t count = 0;
+
+        // loop through until all conditions we're searching for are met
+        FileInputStream fins = file.read(null);
+        var ba = new ByteArray();
+        for (;;) {
+            size_t bytes_read = fins.read(buffer, null);
+            if (bytes_read <= 0)
+                break;
+
+            ba.append(buffer[0:bytes_read]);
+
+            count += bytes_read;
+
+            if (calc_md5)
+                md5_checksum.update(buffer, bytes_read);
+
+            WebP.Data d = WebP.Data();
+            d.bytes = ba.data;
+
+            WebP.ParsingState state;
+            var demux = new WebP.Demuxer.partial(d, out state);
+
+            if (state == WebP.ParsingState.PARSE_ERROR) {
+                is_corrupted = true;
+                break;
+            }
+
+            if (state > WebP.ParsingState.PARSED_HEADER) {
+                detected.file_format = PhotoFileFormat.WEBP;
+                detected.format_name = "WebP";
+                detected.channels = 4;
+                detected.bits_per_channel = 8;
+                detected.image_dim.width = (int) demux.get(WebP.FormatFeature.CANVAS_WIDTH);
+                detected.image_dim.height = (int) demux.get(WebP.FormatFeature.CANVAS_HEIGHT);
+
+                // if not searching for anything else, exit
+                if (!calc_md5)
+                    break;
+            }
+        }
+
+        if (fins != null)
+            fins.close(null);
+
+        if (calc_md5)
+            detected.md5 = md5_checksum.get_string();
+
+        return detected;
+    }
+}
+
+private class WebpReader : PhotoFileReader {
+    public WebpReader(string filepath) {
+        base (filepath, PhotoFileFormat.WEBP);
+    }
+
+    public override PhotoMetadata read_metadata() throws Error {
+        PhotoMetadata metadata = new PhotoMetadata();
+        metadata.read_from_file(get_file());
+
+        return metadata;
+    }
+
+    public override Gdk.Pixbuf unscaled_read() throws Error {
+        uint8[] buffer;
+
+        FileUtils.get_data(this.get_filepath(), out buffer);
+        int width, height;
+        var pixdata = WebP.DecodeRGBA(buffer, out width, out height);
+        pixdata.length = width * height * 4;
+
+        return new Gdk.Pixbuf.from_data(pixdata, Gdk.Colorspace.RGB, true, 8, width, height, width * 4);
+    }
+}
+
+private class WebpMetadataWriter : PhotoFileMetadataWriter {
+    public WebpMetadataWriter(string filepath) {
+        base (filepath, PhotoFileFormat.WEBP);
+    }
+
+    public override void write_metadata(PhotoMetadata metadata) throws Error {
+        metadata.write_to_file(get_file());
+    }
+}
+
+public bool is_webp(File file, Cancellable? cancellable = null) throws Error {
+    var ins = file.read();
+
+    uint8 buffer[12];
+    try {
+        ins.read(buffer, null);
+        if (buffer[0] == 'R' && buffer[1] == 'I' && buffer[2] == 'F' && buffer[3] == 'F' &&
+            buffer[8] == 'W' && buffer[9] == 'E' && buffer[10] == 'B' && buffer[11] == 'P')
+            return true;
+    } catch (Error error) {
+        debug ("Failed to read from file %s: %s", file.get_path (), error.message);
+    }
+
+    return false;
+}
+
+}