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/* Copyright 2010-2015 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(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)
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;
}
}
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