Logo Search packages:      
Sourcecode: f-spot version File versions  Download package

File.cs

//
// File.cs: Provides tagging for Canon CR2 files
//
// Author:
//   Mike Gemuende (mike@gemuende.be)
//
// Copyright (C) 2010 Mike Gemuende
//
// This library is free software; you can redistribute it and/or modify
// it  under the terms of the GNU Lesser General Public License version
// 2.1 as published by the Free Software Foundation.
//
// This library is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
// USA
//

using System;
using System.Collections.Generic;

using TagLib;
using TagLib.Image;
using TagLib.IFD;
using TagLib.IFD.Tags;

namespace TagLib.Tiff.Cr2
{

      /// <summary>
      ///    This class extends <see cref="TagLib.Tiff.BaseTiffFile" /> to provide tagging
      ///    for CR2 image files.
      /// </summary>
      [SupportedMimeType("taglib/cr2", "cr2")]
      [SupportedMimeType("image/cr2")]
      [SupportedMimeType("image/x-canon-cr2")]
00042       public class File : TagLib.Tiff.BaseTiffFile
      {
#region private fields

            /// <summary>
            ///    The Properties of the image
            /// </summary>
00049             private Properties properties;

#endregion

#region public Properties

            /// <summary>
            ///    Gets the media properties of the file represented by the
            ///    current instance.
            /// </summary>
            /// <value>
            ///    A <see cref="TagLib.Properties" /> object containing the
            ///    media properties of the file represented by the current
            ///    instance.
            /// </value>
00064             public override TagLib.Properties Properties {
                  get { return properties; }
            }

            /// <summary>
            ///    Indicates if tags can be written back to the current file or not
            /// </summary>
            /// <value>
            ///    A <see cref="bool" /> which is true if tags can be written to the
            ///    current file, otherwise false.
            /// </value>
00075             public override bool Writeable {
                  get { return false; }
            }


#endregion

#region constructors

            /// <summary>
            ///    Constructs and initializes a new instance of <see
            ///    cref="File" /> for a specified path in the local file
            ///    system and specified read style.
            /// </summary>
            /// <param name="path">
            ///    A <see cref="string" /> object containing the path of the
            ///    file to use in the new instance.
            /// </param>
            /// <param name="propertiesStyle">
            ///    A <see cref="ReadStyle" /> value specifying at what level
            ///    of accuracy to read the media properties, or <see
            ///    cref="ReadStyle.None" /> to ignore the properties.
            /// </param>
            /// <exception cref="ArgumentNullException">
            ///    <paramref name="path" /> is <see langword="null" />.
            /// </exception>
00101             public File (string path, ReadStyle propertiesStyle)
                  : this (new File.LocalFileAbstraction (path),
                        propertiesStyle)
            {
            }

            /// <summary>
            ///    Constructs and initializes a new instance of <see
            ///    cref="File" /> for a specified path in the local file
            ///    system.
            /// </summary>
            /// <param name="path">
            ///    A <see cref="string" /> object containing the path of the
            ///    file to use in the new instance.
            /// </param>
            /// <exception cref="ArgumentNullException">
            ///    <paramref name="path" /> is <see langword="null" />.
            /// </exception>
00119             public File (string path) : this (path, ReadStyle.Average)
            {
            }

            /// <summary>
            ///    Constructs and initializes a new instance of <see
            ///    cref="File" /> for a specified file abstraction and
            ///    specified read style.
            /// </summary>
            /// <param name="abstraction">
            ///    A <see cref="IFileAbstraction" /> object to use when
            ///    reading from and writing to the file.
            /// </param>
            /// <param name="propertiesStyle">
            ///    A <see cref="ReadStyle" /> value specifying at what level
            ///    of accuracy to read the media properties, or <see
            ///    cref="ReadStyle.None" /> to ignore the properties.
            /// </param>
            /// <exception cref="ArgumentNullException">
            ///    <paramref name="abstraction" /> is <see langword="null"
            ///    />.
            /// </exception>
00141             public File (File.IFileAbstraction abstraction,
                         ReadStyle propertiesStyle) : base (abstraction)
            {
                  Read (propertiesStyle);
            }

            /// <summary>
            ///    Constructs and initializes a new instance of <see
            ///    cref="File" /> for a specified file abstraction.
            /// </summary>
            /// <param name="abstraction">
            ///    A <see cref="IFileAbstraction" /> object to use when
            ///    reading from and writing to the file.
            /// </param>
            /// <exception cref="ArgumentNullException">
            ///    <paramref name="abstraction" /> is <see langword="null"
            ///    />.
            /// </exception>
00159             protected File (IFileAbstraction abstraction)
                  : this (abstraction, ReadStyle.Average)
            {
            }

#endregion

#region Public Methods

            /// <summary>
            ///    Saves the changes made in the current instance to the
            ///    file it represents.
            /// </summary>
00172             public override void Save ()
            {
                  throw new NotSupportedException ();
            }

#endregion

#region private methods

            /// <summary>
            ///    Reads the information from file with a specified read style.
            /// </summary>
            /// <param name="propertiesStyle">
            ///    A <see cref="ReadStyle" /> value specifying at what level
            ///    of accuracy to read the media properties, or <see
            ///    cref="ReadStyle.None" /> to ignore the properties.
            /// </param>
00189             private void Read (ReadStyle propertiesStyle)
            {
                  Mode = AccessMode.Read;
                  try {
                        ImageTag = new CombinedImageTag (TagTypes.TiffIFD);

                        ReadFile ();

                        TagTypesOnDisk = TagTypes;

                        if (propertiesStyle != ReadStyle.None)
                              properties = ExtractProperties ();

                  } finally {
                        Mode = AccessMode.Closed;
                  }
            }

            /// <summary>
            ///    Parses the CR2 file
            /// </summary>
00210             private void ReadFile ()
            {
                  // A CR2 file starts with a Tiff header followed by a CR2 header
                  uint first_ifd_offset = ReadHeader ();
                  uint raw_ifd_offset = ReadAdditionalCR2Header ();

                  ReadIFD (first_ifd_offset, 3);
                  ReadIFD (raw_ifd_offset, 1);
            }

            /// <summary>
            ///   Reads and validates the CR2 header started at the current position.
            /// </summary>
            /// <returns>
            ///    A <see cref="System.UInt32"/> with the offset to the IFD with the RAW data.
            /// </returns>
00226             private uint ReadAdditionalCR2Header ()
            {
                  // CR2 Header
                  //
                  // CR2 Information:
                  //
                  // 2 bytes         CR2 Magic word (CR)
                  // 1 byte          CR2 major version (2)
                  // 1 byte          CR2 minor version (0)
                  // 4 bytes         Offset to RAW IFD
                  //

                  ByteVector header = ReadBlock (8);

                  if (header.Count != 8)
                        throw new CorruptFileException ("Unexpected end of CR2 header");

                  if (header.Mid (0, 2).ToString () != "CR")
                        throw new CorruptFileException("CR2 Magic (CR) expected");

                  byte major_version = header [2];
                  byte minor_version = header [3];

                  if (major_version != 2 || minor_version != 0)
                        throw new UnsupportedFormatException ("Only major version 2 and minor version 0 are supported");

                  uint raw_ifd_offset = header.Mid (4, 4).ToUInt (IsBigEndian);

                  return raw_ifd_offset;
            }

            /// <summary>
            ///    Attempts to extract the media properties of the main
            ///    photo.
            /// </summary>
            /// <returns>
            ///    A <see cref="Properties" /> object with a best effort guess
            ///    at the right values. When no guess at all can be made,
            ///    <see langword="null" /> is returned.
            /// </returns>
00266             private Properties ExtractProperties ()
            {
                  int width = 0, height = 0;

                  IFDTag tag = GetTag (TagTypes.TiffIFD) as IFDTag;

                  width = (int) (tag.ExifIFD.GetLongValue (0, (ushort) ExifEntryTag.PixelXDimension) ?? 0);
                  height = (int) (tag.ExifIFD.GetLongValue (0, (ushort) ExifEntryTag.PixelYDimension) ?? 0);

                  if (width > 0 && height > 0) {
                        return new Properties (TimeSpan.Zero, new Codec (width, height, "Canon RAW File"));
                  }

                  return null;
            }

#endregion


      }
}

Generated by  Doxygen 1.6.0   Back to index