1 files changed, 236 insertions, 0 deletions
diff --git a/src/photos/JfifSupport.vala b/src/photos/JfifSupport.vala
new file mode 100644
index 0000000..12ac80a
--- /dev/null
+++ b/src/photos/JfifSupport.vala
@@ -0,0 +1,236 @@
+/* Copyright 2010-2014 Yorba Foundation
+ *
+ * This software is licensed under the GNU LGPL (version 2.1 or later).
+ * See the COPYING file in this distribution.
+ */
+
+public class JfifFileFormatDriver : PhotoFileFormatDriver {
+    private static JfifFileFormatDriver instance = null;
+
+    public static void init() {
+        instance = new JfifFileFormatDriver();
+        JfifFileFormatProperties.init();
+    }
+    
+    public static JfifFileFormatDriver get_instance() {
+        return instance;
+    }
+    
+    public override PhotoFileFormatProperties get_properties() {
+        return JfifFileFormatProperties.get_instance();
+    }
+    
+    public override PhotoFileReader create_reader(string filepath) {
+        return new JfifReader(filepath);
+    }
+    
+    public override PhotoMetadata create_metadata() {
+        return new PhotoMetadata();
+    }
+    
+    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 JfifWriter(filepath);
+    }
+    
+    public override PhotoFileMetadataWriter? create_metadata_writer(string filepath) {
+        return new JfifMetadataWriter(filepath);
+    }
+    
+    public override PhotoFileSniffer create_sniffer(File file, PhotoFileSniffer.Options options) {
+        return new JfifSniffer(file, options);
+    }
+}
+
+public class JfifFileFormatProperties : PhotoFileFormatProperties {
+    private static string[] KNOWN_EXTENSIONS = {
+        "jpg", "jpeg", "jpe"
+    };
+
+    private static string[] KNOWN_MIME_TYPES = {
+        "image/jpeg"
+    };
+        
+    private static JfifFileFormatProperties instance = null;
+
+    public static void init() {
+        instance = new JfifFileFormatProperties();
+    }
+    
+    public static JfifFileFormatProperties get_instance() {
+        return instance;
+    }
+    
+    public override PhotoFileFormat get_file_format() {
+        return PhotoFileFormat.JFIF;
+    }
+    
+    public override PhotoFileFormatFlags get_flags() {
+        return PhotoFileFormatFlags.NONE;
+    }
+    
+    public override string get_default_extension() {
+        return "jpg";
+    }
+
+    public override string get_user_visible_name() {
+        return _("JPEG");
+    }
+
+    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 JfifSniffer : GdkSniffer {
+    public JfifSniffer(File file, PhotoFileSniffer.Options options) {
+        base (file, options);
+    }
+    
+    public override DetectedPhotoInformation? sniff() throws Error {
+        if (!Jpeg.is_jpeg(file))
+            return null;
+        
+        DetectedPhotoInformation? detected = base.sniff();
+        if (detected == null)
+            return null;
+        
+        return (detected.file_format == PhotoFileFormat.JFIF) ? detected : null;
+    }
+}
+
+public class JfifReader : GdkReader {
+    public JfifReader(string filepath) {
+        base (filepath, PhotoFileFormat.JFIF);
+    }
+}
+
+public class JfifWriter : PhotoFileWriter {
+    public JfifWriter(string filepath) {
+        base (filepath, PhotoFileFormat.JFIF);
+    }
+    
+    public override void write(Gdk.Pixbuf pixbuf, Jpeg.Quality quality) throws Error {
+        pixbuf.save(get_filepath(), "jpeg", "quality", quality.get_pct_text());
+    }
+}
+
+public class JfifMetadataWriter : PhotoFileMetadataWriter {
+    public JfifMetadataWriter(string filepath) {
+        base (filepath, PhotoFileFormat.JFIF);
+    }
+    
+    public override void write_metadata(PhotoMetadata metadata) throws Error {
+        metadata.write_to_file(get_file());
+    }
+}
+
+namespace Jpeg {
+    public const uint8 MARKER_PREFIX = 0xFF;
+    
+    public enum Marker {
+        // Could also be 0xFF according to spec
+        INVALID = 0x00,
+        
+        SOI = 0xD8,
+        EOI = 0xD9,
+        
+        APP0 = 0xE0,
+        APP1 = 0xE1;
+        
+        public uint8 get_byte() {
+            return (uint8) this;
+        }
+    }
+    
+    public enum Quality {
+        LOW = 50,
+        MEDIUM = 75,
+        HIGH = 90,
+        MAXIMUM = 100;
+        
+        public int get_pct() {
+            return (int) this;
+        }
+        
+        public string get_pct_text() {
+            return "%d".printf((int) this);
+        }
+        
+        public static Quality[] get_all() {
+            return { LOW, MEDIUM, HIGH, MAXIMUM };
+        }
+        
+        public string? to_string() {
+            switch (this) {
+                case LOW:
+                    return _("Low (%d%%)").printf((int) this);
+                
+                case MEDIUM:
+                    return _("Medium (%d%%)").printf((int) this);
+                
+                case HIGH:
+                    return _("High (%d%%)").printf((int) this);
+                    
+                case MAXIMUM:
+                    return _("Maximum (%d%%)").printf((int) this);
+            }
+            
+            warn_if_reached();
+            
+            return null;
+        }
+    }
+    
+    public bool is_jpeg(File file) throws Error {
+        FileInputStream fins = file.read(null);
+        
+        Marker marker;
+        int segment_length = read_marker(fins, out marker);
+        
+        // for now, merely checking for SOI
+        return (marker == Marker.SOI) && (segment_length == 0);
+    }
+
+    private int read_marker(FileInputStream fins, 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;
+        
+        marker = (Jpeg.Marker) dins.read_byte();
+        if ((marker == Jpeg.Marker.SOI) || (marker == Jpeg.Marker.EOI)) {
+            // no length
+            return 0;
+        }
+        
+        uint16 length = dins.read_uint16();
+        if (length < 2) {
+            debug("Invalid length %Xh at ofs %" + int64.FORMAT + "Xh", length, fins.tell() - 2);
+            
+            return -1;
+        }
+        
+        // account for two length bytes already read
+        return length - 2;
+    }
+}
+