public GifFrame( Stream inputStream,
LogicalScreenDescriptor lsd,
ColourTable gct,
GraphicControlExtension gce,
GifFrame previousFrame,
GifFrame previousFrameBut1 )
: base( inputStream, lsd, gct, gce, previousFrame, previousFrameBut1 )
{}
public GifFrame(Stream inputStream,
LogicalScreenDescriptor lsd,
ColourTable gct,
GraphicControlExtension gce,
GifFrame previousFrame,
GifFrame previousFrameBut1)
: this(inputStream, lsd, gct, gce, previousFrame, previousFrameBut1, false)
{
}
/// <summary>
/// Reads GIF image from stream
/// </summary>
/// <param name="inputStream">
/// Stream containing GIF file.
/// </param>
/// <exception cref="ArgumentNullException">
/// The supplied stream is null.
/// </exception>
private void ReadStream( Stream inputStream )
{
_frames = new Collection<GifFrame>();
_applicationExtensions = new Collection<ApplicationExtension>();
_gct = null;
_readStreamCounterText = "Reading stream byte";
AddCounter( _readStreamCounterText, (int) inputStream.Length );
_header = new GifHeader( inputStream, XmlDebugging );
MyProgressCounters[_readStreamCounterText].Value
= (int) inputStream.Position;
WriteDebugXmlNode( _header.DebugXmlReader );
if( _header.ErrorState != ErrorState.Ok )
{
WriteDebugXmlFinish();
return;
}
_lsd = new LogicalScreenDescriptor( inputStream, XmlDebugging );
MyProgressCounters[_readStreamCounterText].Value
= (int) inputStream.Position;
WriteDebugXmlNode( _lsd.DebugXmlReader );
if( TestState( ErrorState.EndOfInputStream ) )
{
WriteDebugXmlFinish();
return;
}
if( _lsd.HasGlobalColourTable )
{
_gct = new ColourTable( inputStream,
_lsd.GlobalColourTableSize,
XmlDebugging );
MyProgressCounters[_readStreamCounterText].Value
= (int) inputStream.Position;
WriteDebugXmlNode( _gct.DebugXmlReader );
}
if( ConsolidatedState == ErrorState.Ok )
{
ReadContents( inputStream );
MyProgressCounters[_readStreamCounterText].Value
= (int) inputStream.Position;
}
inputStream.Close();
WriteDebugXmlFinish();
RemoveCounter( _readStreamCounterText );
}
public void ConstructorTest()
{
ReportStart();
int width = 15;
int height = 20;
Size screenSize = new Size( width, height );
bool hasGlobalColourTable = true;
int colourResolution = 6;
bool colourTableIsSorted = false;
int globalColourTableSizeBits = 3;
int backgroundColourIndex = 12;
int pixelAspectRatio = 2;
_lsd = new LogicalScreenDescriptor( screenSize,
hasGlobalColourTable,
colourResolution,
colourTableIsSorted,
globalColourTableSizeBits,
backgroundColourIndex,
pixelAspectRatio );
Assert.AreEqual( screenSize, _lsd.LogicalScreenSize );
Assert.AreEqual( hasGlobalColourTable, _lsd.HasGlobalColourTable );
Assert.AreEqual( colourResolution, _lsd.ColourResolution );
Assert.AreEqual( colourTableIsSorted, _lsd.GlobalColourTableIsSorted );
Assert.AreEqual( globalColourTableSizeBits,
_lsd.GlobalColourTableSizeBits );
Assert.AreEqual( Math.Pow( 2, globalColourTableSizeBits + 1 ),
_lsd.GlobalColourTableSize );
Assert.AreEqual( backgroundColourIndex, _lsd.BackgroundColourIndex );
Assert.AreEqual( pixelAspectRatio, _lsd.PixelAspectRatio );
Assert.AreEqual( ErrorState.Ok, _lsd.ConsolidatedState );
ReportEnd();
}
private void ConstructorStreamTest( bool xmlDebugging )
{
int width = 15;
int height = 20;
Size screenSize = new Size( width, height );
bool hasGlobalColourTable = true;
int colourResolution = 6;
bool colourTableIsSorted = false;
int globalColourTableSizeBits = 3;
int backgroundColourIndex = 12;
int pixelAspectRatio = 2;
MemoryStream s = new MemoryStream();
// Write screen width and height, least significant bit first
s.WriteByte( (byte) ( width & 0xff ) );
s.WriteByte( (byte) ( ( width & 0xff00 ) >> 8 ) );
s.WriteByte( (byte) ( height & 0xff ) );
s.WriteByte( (byte) ( ( height & 0xff00 ) >> 8 ) );
// Packed fields:
// bit 1 = global colour table flag
// bits 2-4 = colour resolution
// bit 5 = sort flag
// bits 6-8 = global colour table size
byte packed = (byte)
(
( hasGlobalColourTable ? 1 : 0 ) << 7
| ( colourResolution & 7 ) << 4
| ( colourTableIsSorted ? 1 : 0 ) << 3
| ( globalColourTableSizeBits & 7 )
);
s.WriteByte( packed );
s.WriteByte( (byte) backgroundColourIndex );
s.WriteByte( (byte) pixelAspectRatio );
s.Seek( 0, SeekOrigin.Begin );
_lsd = new LogicalScreenDescriptor( s, xmlDebugging );
Assert.AreEqual( ErrorState.Ok, _lsd.ConsolidatedState );
Assert.AreEqual( screenSize, _lsd.LogicalScreenSize );
Assert.AreEqual( hasGlobalColourTable, _lsd.HasGlobalColourTable );
Assert.AreEqual( colourResolution, _lsd.ColourResolution );
Assert.AreEqual( colourTableIsSorted, _lsd.GlobalColourTableIsSorted );
Assert.AreEqual( globalColourTableSizeBits,
_lsd.GlobalColourTableSizeBits );
Assert.AreEqual( Math.Pow( 2, globalColourTableSizeBits + 1 ),
_lsd.GlobalColourTableSize );
Assert.AreEqual( backgroundColourIndex, _lsd.BackgroundColourIndex );
Assert.AreEqual( pixelAspectRatio, _lsd.PixelAspectRatio );
Assert.AreEqual( ErrorState.Ok, _lsd.ConsolidatedState );
if( xmlDebugging )
{
Assert.AreEqual( ExpectedDebugXml, _lsd.DebugXml );
}
}
private void ConstructorStreamEndOfStreamTest( bool xmlDebugging )
{
Size screenSize = new Size( 12, 4 );
bool hasGlobalColourTable = false;
int colourResolution = 3;
bool globalColourTableIsSorted = true;
int globalColourTableSizeBits = 4;
int backgroundColourIndex = 2;
int pixelAspectRatio = 1;
_lsd = new LogicalScreenDescriptor( screenSize,
hasGlobalColourTable,
colourResolution,
globalColourTableIsSorted,
globalColourTableSizeBits,
backgroundColourIndex,
pixelAspectRatio );
MemoryStream s = new MemoryStream();
_lsd.WriteToStream( s );
s.SetLength( s.Length - 1 ); // remove final byte from stream
s.Seek( 0, SeekOrigin.Begin );
_lsd = new LogicalScreenDescriptor( s, xmlDebugging );
Assert.AreEqual( ErrorState.EndOfInputStream, _lsd.ConsolidatedState );
Assert.AreEqual( screenSize, _lsd.LogicalScreenSize );
Assert.AreEqual( hasGlobalColourTable, _lsd.HasGlobalColourTable );
Assert.AreEqual( colourResolution, _lsd.ColourResolution );
Assert.AreEqual( globalColourTableIsSorted, _lsd.GlobalColourTableIsSorted );
Assert.AreEqual( globalColourTableSizeBits, _lsd.GlobalColourTableSizeBits );
Assert.AreEqual( backgroundColourIndex, _lsd.BackgroundColourIndex );
Assert.AreEqual( -1, _lsd.PixelAspectRatio );
if( xmlDebugging )
{
Assert.AreEqual( ExpectedDebugXml, _lsd.DebugXml );
}
}
private void DecodeSmiley( bool xmlDebugging )
{
string fileName = @"images\smiley\smiley.gif";
_decoder = new GifDecoder( fileName, xmlDebugging );
_decoder.Decode();
_lsd = _decoder.LogicalScreenDescriptor;
int expectedColourTableSize = 128;
Assert.AreEqual( "GIF", _decoder.Header.Signature );
Assert.AreEqual( "89a", _decoder.Header.Version );
Assert.IsNotNull( _decoder.GlobalColourTable );
Assert.AreEqual( true, _lsd.HasGlobalColourTable );
Assert.AreEqual( expectedColourTableSize,
_lsd.GlobalColourTableSize );
Assert.AreEqual( expectedColourTableSize,
_decoder.GlobalColourTable.Length );
Assert.AreEqual( 7, _lsd.ColourResolution );
Assert.AreEqual( Color.FromArgb( 255, 0, 0, 255 ), _decoder.BackgroundColour );
Assert.AreEqual( 0, _lsd.BackgroundColourIndex );
Assert.AreEqual( false, _lsd.GlobalColourTableIsSorted );
Assert.AreEqual( 18, _lsd.LogicalScreenSize.Width );
Assert.AreEqual( 18, _lsd.LogicalScreenSize.Height );
Assert.AreEqual( 0, _lsd.PixelAspectRatio );
Assert.AreEqual( 0, _decoder.NetscapeExtension.LoopCount );
Assert.AreEqual( ErrorState.Ok, _decoder.ConsolidatedState );
Assert.AreEqual( 4, _decoder.Frames.Count );
int frameNumber = 0;
string frameId;
foreach( GifFrame thisFrame in _decoder.Frames )
{
frameId = "Frame " + frameNumber;
Assert.IsNull( thisFrame.LocalColourTable, frameId );
#region image descriptor properties
ImageDescriptor descriptor = thisFrame.ImageDescriptor;
Assert.AreEqual( false, descriptor.HasLocalColourTable, frameId );
Assert.AreEqual( expectedColourTableSize,
descriptor.LocalColourTableSize,
frameId );
Assert.AreEqual( false, descriptor.IsInterlaced, frameId );
Assert.AreEqual( false, descriptor.IsSorted, frameId );
#endregion
#region graphic control extension properties
GraphicControlExtension gce = thisFrame.GraphicControlExtension;
Assert.AreEqual( 4, gce.BlockSize, frameId );
Assert.AreEqual( 0, gce.TransparentColourIndex, frameId );
Assert.IsTrue( gce.HasTransparentColour, frameId );
Assert.IsFalse( gce.ExpectsUserInput, frameId );
#endregion
switch( frameNumber )
{
case 0:
Assert.AreEqual( 250, thisFrame.Delay, frameId );
Assert.AreEqual( 250, gce.DelayTime, frameId );
Assert.AreEqual( DisposalMethod.DoNotDispose,
gce.DisposalMethod, frameId );
break;
case 1:
Assert.AreEqual( 5, thisFrame.Delay, frameId );
Assert.AreEqual( 5, gce.DelayTime, frameId );
Assert.AreEqual( DisposalMethod.RestoreToBackgroundColour,
gce.DisposalMethod, frameId );
break;
case 2:
Assert.AreEqual( 10, thisFrame.Delay, frameId );
Assert.AreEqual( 10, gce.DelayTime, frameId );
Assert.AreEqual( DisposalMethod.RestoreToBackgroundColour,
gce.DisposalMethod, frameId );
break;
case 3:
Assert.AreEqual( 5, thisFrame.Delay, frameId );
Assert.AreEqual( 5, gce.DelayTime, frameId );
Assert.AreEqual( DisposalMethod.DoNotDispose,
gce.DisposalMethod, frameId );
break;
}
frameNumber++;
}
CompareFrames( fileName );
if( xmlDebugging )
{
Assert.AreEqual( ExpectedDebugXml, _decoder.DebugXml );
}
}
/// <summary>
/// Gets the base image for this frame. This will be overpainted with
/// the pixels for this frame, where they are not transparent.
/// </summary>
/// <param name="previousFrame">
/// The frame which preceded this frame in the GIF stream.
/// Null if this is the first frame in the stream.
/// </param>
/// <param name="previousFrameBut1">
/// The frame which preceded the previous frame in the GIF stream.
/// Null if this is the first or seond frame in the stream.
/// </param>
/// <param name="lsd">
/// The logical screen descriptor for this GIF stream.
/// </param>
/// <param name="gce">
/// The graphic control extension for this frame.
/// </param>
/// <param name="act">
/// The active colour table for this frame.
/// </param>
/// <returns></returns>
private static Bitmap GetBaseImage( GifFrame previousFrame,
GifFrame previousFrameBut1,
LogicalScreenDescriptor lsd,
GraphicControlExtension gce,
ColourTable act )
{
#region Get the disposal method of the previous frame read from the GIF stream
DisposalMethod previousDisposalMethod;
if( previousFrame == null )
{
previousDisposalMethod = DisposalMethod.NotSpecified;
}
else
{
previousDisposalMethod = previousFrame.GraphicControlExtension.DisposalMethod;
}
#endregion
Bitmap baseImage;
int width = lsd.LogicalScreenSize.Width;
int height = lsd.LogicalScreenSize.Height;
#region paint baseImage
switch( previousDisposalMethod )
{
case DisposalMethod.DoNotDispose:
// pre-populate image with previous frame
baseImage = new Bitmap( previousFrame.TheImage );
break;
case DisposalMethod.RestoreToBackgroundColour:
// pre-populate image with background colour
Color backgroundColour ;
if( lsd.BackgroundColourIndex == gce.TransparentColourIndex )
{
backgroundColour = Color.Empty;
}
else
{
// TESTME: background colour index different to transparent colour
backgroundColour = act[lsd.BackgroundColourIndex];
}
baseImage = new Bitmap( width, height );
for( int y = 0; y < height; y++ )
{
for( int x = 0; x < height; x++ )
{
baseImage.SetPixel( x, y, backgroundColour );
}
}
break;
case DisposalMethod.RestoreToPrevious:
// pre-populate image with previous frame but 1
// TESTME: DisposalMethod.RestoreToPrevious
baseImage = new Bitmap( previousFrameBut1.TheImage );
break;
default: // DisposalMethod.NotSpecified
if( previousFrame == null )
{
// this is the first frame so start with an empty bitmap
baseImage = new Bitmap( width, height );
}
else
{
// pre-populate image with previous frame
// TESTME: DisposalMethod.NotSpecified on 2nd frame or later
baseImage = new Bitmap( previousFrame.TheImage );
}
break;
}
#endregion
return baseImage;
}
private static LogicalScreenDescriptor CheckLogicalScreenDescriptor( Stream s,
bool shouldHaveGlobalColourTable)
{
// check logical screen descriptor
LogicalScreenDescriptor lsd = new LogicalScreenDescriptor( s );
Assert.AreEqual( ErrorState.Ok,
lsd.ConsolidatedState,
"Logical screen descriptor consolidated state" );
Assert.AreEqual( new Size( 2, 2 ),
lsd.LogicalScreenSize,
"Logical screen size" );
Assert.AreEqual( shouldHaveGlobalColourTable,
lsd.HasGlobalColourTable,
"Should have global colour table" );
Assert.AreEqual( false,
lsd.GlobalColourTableIsSorted,
"Global colour table is sorted" );
return lsd;
}
public void WikipediaExampleTest()
{
ReportStart();
_e = new AnimatedGifEncoder();
GifFrame frame = new GifFrame( WikipediaExample.ExpectedBitmap );
frame.Delay = WikipediaExample.DelayTime;
_e.AddFrame( frame );
// TODO: some way of creating/testing a UseLocal version of WikipediaExample
string fileName = "WikipediaExampleUseGlobal.gif";
_e.WriteToFile( fileName );
Stream s = File.OpenRead( fileName );
int code;
// check GIF header
GifHeader gh = new GifHeader( s );
Assert.AreEqual( ErrorState.Ok, gh.ConsolidatedState );
// check logical screen descriptor
LogicalScreenDescriptor lsd = new LogicalScreenDescriptor( s );
Assert.AreEqual( ErrorState.Ok, lsd.ConsolidatedState );
WikipediaExample.CheckLogicalScreenDescriptor( lsd );
// read global colour table
ColourTable gct
= new ColourTable( s, WikipediaExample.GlobalColourTableSize );
Assert.AreEqual( ErrorState.Ok, gct.ConsolidatedState );
// cannot compare global colour table as different encoders will
// produce difference colour tables.
// WikipediaExample.CheckGlobalColourTable( gct );
// check for extension introducer
code = ExampleComponent.CallRead( s );
Assert.AreEqual( GifComponent.CodeExtensionIntroducer, code );
// check for app extension label
code = ExampleComponent.CallRead( s );
Assert.AreEqual( GifComponent.CodeApplicationExtensionLabel, code );
// check netscape extension
ApplicationExtension ae = new ApplicationExtension( s );
Assert.AreEqual( ErrorState.Ok, ae.ConsolidatedState );
NetscapeExtension ne = new NetscapeExtension( ae );
Assert.AreEqual( ErrorState.Ok, ne.ConsolidatedState );
Assert.AreEqual( 0, ne.LoopCount );
// check for extension introducer
code = ExampleComponent.CallRead( s );
Assert.AreEqual( GifComponent.CodeExtensionIntroducer, code );
// check for gce label
code = ExampleComponent.CallRead( s );
Assert.AreEqual( GifComponent.CodeGraphicControlLabel, code );
// check graphic control extension
GraphicControlExtension gce = new GraphicControlExtension( s );
Assert.AreEqual( ErrorState.Ok, gce.ConsolidatedState );
WikipediaExample.CheckGraphicControlExtension( gce );
// check for image separator
code = ExampleComponent.CallRead( s );
Assert.AreEqual( GifComponent.CodeImageSeparator, code );
// check for image descriptor
ImageDescriptor id = new ImageDescriptor( s );
Assert.AreEqual( ErrorState.Ok, id.ConsolidatedState );
WikipediaExample.CheckImageDescriptor( id );
// read, decode and check image data
// Cannot compare encoded LZW data directly as different encoders
// will create different colour tables, so even if the bitmaps are
// identical, the colour indices will be different
int pixelCount = WikipediaExample.FrameSize.Width
* WikipediaExample.FrameSize.Height;
TableBasedImageData tbid = new TableBasedImageData( s, pixelCount );
for( int y = 0; y < WikipediaExample.LogicalScreenSize.Height; y++ )
{
for( int x = 0; x < WikipediaExample.LogicalScreenSize.Width; x++ )
{
int i = (y * WikipediaExample.LogicalScreenSize.Width) + x;
Assert.AreEqual( WikipediaExample.ExpectedBitmap.GetPixel( x, y ),
gct[tbid.Pixels[i]],
"X: " + x + ", Y: " + y );
}
}
// Check for block terminator after image data
code = ExampleComponent.CallRead( s );
Assert.AreEqual( 0x00, code );
// check for GIF trailer
code = ExampleComponent.CallRead( s );
Assert.AreEqual( GifComponent.CodeTrailer, code );
// check we're at the end of the stream
code = ExampleComponent.CallRead( s );
Assert.AreEqual( -1, code );
s.Close();
_d = new GifDecoder( fileName );
_d.Decode();
Assert.AreEqual( ErrorState.Ok, _d.ConsolidatedState );
BitmapAssert.AreEqual( WikipediaExample.ExpectedBitmap,
(Bitmap) _d.Frames[0].TheImage,
"" );
ReportEnd();
}
/// <summary>
/// Gets the base image for this frame. This will be overpainted with
/// the pixels for this frame, where they are not transparent.
/// </summary>
/// <param name="previousFrame">
/// The frame which preceded this frame in the GIF stream.
/// Null if this is the first frame in the stream.
/// </param>
/// <param name="previousFrameBut1">
/// The frame which preceded the previous frame in the GIF stream.
/// Null if this is the first or seond frame in the stream.
/// </param>
/// <param name="lsd">
/// The logical screen descriptor for this GIF stream.
/// </param>
/// <param name="gce">
/// The graphic control extension for this frame.
/// </param>
/// <param name="act">
/// The active colour table for this frame.
/// </param>
/// <returns></returns>
private static Bitmap GetBaseImage(GifFrame previousFrame,
GifFrame previousFrameBut1,
LogicalScreenDescriptor lsd,
GraphicControlExtension gce,
ColourTable act)
{
#region Get the disposal method of the previous frame read from the GIF stream
DisposalMethod previousDisposalMethod;
if (previousFrame == null)
{
previousDisposalMethod = DisposalMethod.NotSpecified;
}
else
{
previousDisposalMethod = previousFrame.GraphicControlExtension.DisposalMethod;
}
#endregion
Bitmap baseImage;
int width = lsd.LogicalScreenSize.Width;
int height = lsd.LogicalScreenSize.Height;
#region paint baseImage
switch (previousDisposalMethod)
{
case DisposalMethod.DoNotDispose:
// pre-populate image with previous frame
baseImage = new Bitmap(previousFrame.TheImage);
break;
case DisposalMethod.RestoreToBackgroundColour:
// pre-populate image with background colour
Color backgroundColour;
if (lsd.BackgroundColourIndex == gce.TransparentColourIndex)
{
backgroundColour = Color.Empty;
}
else
{
// TESTME: background colour index different to transparent colour
backgroundColour = act[lsd.BackgroundColourIndex];
}
baseImage = new Bitmap(width, height);
for (int y = 0; y < height; y++)
{
for (int x = 0; x < height; x++)
{
baseImage.SetPixel(x, y, backgroundColour);
}
}
break;
case DisposalMethod.RestoreToPrevious:
// pre-populate image with previous frame but 1
// TESTME: DisposalMethod.RestoreToPrevious
baseImage = new Bitmap(previousFrameBut1.TheImage);
break;
default: // DisposalMethod.NotSpecified
if (previousFrame == null)
{
// this is the first frame so start with an empty bitmap
baseImage = new Bitmap(width, height);
}
else
{
// pre-populate image with previous frame
// TESTME: DisposalMethod.NotSpecified on 2nd frame or later
baseImage = new Bitmap(previousFrame.TheImage);
}
break;
}
#endregion
return(baseImage);
}
/// <summary>
/// Sets the pixels of the decoded image.
/// </summary>
/// <param name="imageData">
/// Table based image data containing the indices within the active
/// colour table of the colours of the pixels in this frame.
/// </param>
/// <param name="lsd">
/// The logical screen descriptor for the GIF stream.
/// </param>
/// <param name="id">
/// The image descriptor for this frame.
/// </param>
/// <param name="activeColourTable">
/// The colour table to use with this frame - either the global colour
/// table or a local colour table.
/// </param>
/// <param name="gce">
/// The graphic control extension, if any, which precedes this image in
/// the input stream.
/// </param>
/// <param name="previousFrame">
/// The frame which precedes this one in the GIF stream, if present.
/// </param>
/// <param name="previousFrameBut1">
/// The frame which precedes the frame before this one in the GIF stream,
/// if present.
/// </param>
/// <param name="status">
/// GifComponentStatus containing any errors which occurred during the
/// creation of the bitmap.
/// </param>
private static Bitmap CreateBitmap(TableBasedImageData imageData,
LogicalScreenDescriptor lsd,
ImageDescriptor id,
ColourTable activeColourTable,
GraphicControlExtension gce,
GifFrame previousFrame,
GifFrame previousFrameBut1,
out GifComponentStatus status)
{
status = new GifComponentStatus(ErrorState.Ok, "");
Color[] pixelsForThisFrame = new Color[lsd.LogicalScreenSize.Width
* lsd.LogicalScreenSize.Height];
Bitmap baseImage = GetBaseImage(previousFrame,
previousFrameBut1,
lsd,
gce,
activeColourTable);
// copy each source line to the appropriate place in the destination
int pass = 1;
int interlaceRowIncrement = 8;
int interlaceRowNumber = 0; // the row of pixels we're currently
// setting in an interlaced image.
for (int i = 0; i < id.Size.Height; i++)
{
int pixelRowNumber = i;
if (id.IsInterlaced)
{
#region work out the pixel row we're setting for an interlaced image
if (interlaceRowNumber >= id.Size.Height)
{
pass++;
switch (pass)
{
case 2:
interlaceRowNumber = 4;
break;
case 3:
interlaceRowNumber = 2;
interlaceRowIncrement = 4;
break;
case 4:
interlaceRowNumber = 1;
interlaceRowIncrement = 2;
break;
}
}
#endregion
pixelRowNumber = interlaceRowNumber;
interlaceRowNumber += interlaceRowIncrement;
}
// Colour in the pixels for this row
pixelRowNumber += id.Position.Y;
if (pixelRowNumber < lsd.LogicalScreenSize.Height)
{
int k = pixelRowNumber * lsd.LogicalScreenSize.Width;
int dx = k + id.Position.X; // start of line in dest
int dlim = dx + id.Size.Width; // end of dest line
if ((k + lsd.LogicalScreenSize.Width) < dlim)
{
// TESTME: CreateBitmap - past dest edge
dlim = k + lsd.LogicalScreenSize.Width; // past dest edge
}
int sx = i * id.Size.Width; // start of line in source
while (dx < dlim)
{
// map color and insert in destination
int indexInColourTable = (int)imageData.Pixels[sx++];
// Set this pixel's colour if its index isn't the
// transparent colour index, or if this frame doesn't
// have a transparent colour.
Color c;
if (gce.HasTransparentColour && indexInColourTable == gce.TransparentColourIndex)
{
c = Color.Empty; // transparent pixel
}
else
{
if (indexInColourTable < activeColourTable.Length)
{
c = activeColourTable[indexInColourTable];
}
else
{
// TESTME: CreateBitmap - BadColourIndex
c = Color.Black;
string message
= "Colour index: "
+ indexInColourTable
+ ", colour table length: "
+ activeColourTable.Length
+ " (" + dx + "," + pixelRowNumber + ")";
status = new GifComponentStatus(ErrorState.BadColourIndex,
message);
}
}
pixelsForThisFrame[dx] = c;
dx++;
}
}
}
return(CreateBitmap(baseImage, pixelsForThisFrame));
}
public GifFrame(Stream inputStream,
LogicalScreenDescriptor lsd,
ColourTable gct,
GraphicControlExtension gce,
GifFrame previousFrame,
GifFrame previousFrameBut1,
bool xmlDebugging)
: base(xmlDebugging)
{
#region guard against null arguments
if (lsd == null)
{
throw new ArgumentNullException("lsd");
}
if (gce == null)
{
SetStatus(ErrorState.NoGraphicControlExtension, "");
// use a default GCE
gce = new GraphicControlExtension(GraphicControlExtension.ExpectedBlockSize,
DisposalMethod.NotSpecified,
false,
false,
100,
0);
}
#endregion
int transparentColourIndex = gce.TransparentColourIndex;
ImageDescriptor imageDescriptor = new ImageDescriptor(inputStream,
XmlDebugging);
WriteDebugXmlNode(imageDescriptor.DebugXmlReader);
#region determine the colour table to use for this frame
Color backgroundColour = Color.FromArgb(0); // TODO: is this the right background colour?
// TODO: use backgroundColourIndex from the logical screen descriptor?
ColourTable activeColourTable;
if (imageDescriptor.HasLocalColourTable)
{
_localColourTable
= new ColourTable(inputStream,
imageDescriptor.LocalColourTableSize,
XmlDebugging);
WriteDebugXmlNode(_localColourTable.DebugXmlReader);
activeColourTable = _localColourTable; // make local table active
}
else
{
if (gct == null)
{
// We have neither local nor global colour table, so we
// won't be able to decode this frame.
Bitmap emptyBitmap = new Bitmap(lsd.LogicalScreenSize.Width,
lsd.LogicalScreenSize.Height);
_image = emptyBitmap;
_delay = gce.DelayTime;
SetStatus(ErrorState.FrameHasNoColourTable, "");
return;
}
activeColourTable = gct; // make global table active
if (lsd.BackgroundColourIndex == transparentColourIndex)
{
backgroundColour = Color.FromArgb(0);
}
}
#endregion
// decode pixel data
int pixelCount = imageDescriptor.Size.Width * imageDescriptor.Size.Height;
TableBasedImageData indexedPixels
= new TableBasedImageData(inputStream, pixelCount, XmlDebugging);
WriteDebugXmlNode(indexedPixels.DebugXmlReader);
if (indexedPixels.Pixels.Count == 0)
{
// TESTME: constructor - indexedPixels.Pixels.Count == 0
Bitmap emptyBitmap = new Bitmap(lsd.LogicalScreenSize.Width,
lsd.LogicalScreenSize.Height);
_image = emptyBitmap;
_delay = gce.DelayTime;
SetStatus(ErrorState.FrameHasNoImageData, "");
WriteDebugXmlFinish();
return;
}
// Skip any remaining blocks up to the next block terminator (in
// case there is any surplus data before the next frame)
SkipBlocks(inputStream);
_indexedPixels = indexedPixels;
_extension = gce;
if (gce != null)
{
_delay = gce.DelayTime;
}
_imageDescriptor = imageDescriptor;
_backgroundColour = backgroundColour;
GifComponentStatus status;
_image = CreateBitmap(indexedPixels,
lsd,
imageDescriptor,
activeColourTable,
gce,
previousFrame,
previousFrameBut1,
out status);
WriteDebugXmlFinish();
}
/// <summary>
/// Writes a Logical Screen Descriptor to the supplied stream.
/// Also writes a global colour table if required.
/// </summary>
/// <param name="outputStream">
/// The stream to write to.
/// </param>
private void WriteLogicalScreenDescriptor( Stream outputStream )
{
bool hasGlobalColourTable = _strategy == ColourTableStrategy.UseGlobal;
int colourResolution = 7; // TODO: parameterise colourResolution?
bool globalColourTableIsSorted = false; // Sorting of colour tables is not currently supported
int backgroundColorIndex = 0; // TODO: parameterise backgroundColourIndex?
int pixelAspectRatio = 0; // TODO: parameterise pixelAspectRatio?
if( _strategy == ColourTableStrategy.UseGlobal )
{
if( _quantizerType == QuantizerType.UseSuppliedPalette )
{
// use supplied palette
_globalColourTable = new ColourTable();
string buildColourTableCounterText
= "Building colour table from supplied palette";
AddCounter( buildColourTableCounterText,
_palette.Count );
int paletteIndex = 0;
foreach( Color c in _palette )
{
_globalColourTable.Add( c );
MyProgressCounters[buildColourTableCounterText].Value
= paletteIndex;
paletteIndex++;
}
_globalColourTable.Pad();
RemoveCounter( buildColourTableCounterText );
}
else
{
// Analyse the pixels in all the images to build the
// global colour table.
Collection<Image> images = new Collection<Image>();
foreach( GifFrame thisFrame in _frames )
{
Image thisImage = thisFrame.TheImage;
images.Add( thisImage );
}
_pixelAnalysis = new PixelAnalysis( images );
_pixelAnalysis.ColourQuality = _quality;
_pixelAnalysis.Analyse();
_globalColourTable = _pixelAnalysis.ColourTable;
}
LogicalScreenDescriptor lsd =
new LogicalScreenDescriptor( _logicalScreenSize,
hasGlobalColourTable,
colourResolution,
globalColourTableIsSorted,
_globalColourTable.SizeBits,
backgroundColorIndex,
pixelAspectRatio );
lsd.WriteToStream( outputStream );
_globalColourTable.WriteToStream( outputStream );
}
else
{
LogicalScreenDescriptor lsd =
new LogicalScreenDescriptor( _logicalScreenSize,
hasGlobalColourTable,
colourResolution,
globalColourTableIsSorted,
7,
backgroundColorIndex,
pixelAspectRatio );
lsd.WriteToStream( outputStream );
}
}
public GifFrame( Stream inputStream,
LogicalScreenDescriptor lsd,
ColourTable gct,
GraphicControlExtension gce,
GifFrame previousFrame,
GifFrame previousFrameBut1,
bool xmlDebugging )
: base( xmlDebugging )
{
#region guard against null arguments
if( lsd == null )
{
throw new ArgumentNullException( "lsd" );
}
if( gce == null )
{
SetStatus( ErrorState.NoGraphicControlExtension, "" );
// use a default GCE
gce = new GraphicControlExtension( GraphicControlExtension.ExpectedBlockSize,
DisposalMethod.NotSpecified,
false,
false,
100,
0 );
}
#endregion
int transparentColourIndex = gce.TransparentColourIndex;
ImageDescriptor imageDescriptor = new ImageDescriptor( inputStream,
XmlDebugging );
WriteDebugXmlNode( imageDescriptor.DebugXmlReader );
#region determine the colour table to use for this frame
Color backgroundColour = Color.FromArgb( 0 ); // TODO: is this the right background colour?
// TODO: use backgroundColourIndex from the logical screen descriptor?
ColourTable activeColourTable;
if( imageDescriptor.HasLocalColourTable )
{
_localColourTable
= new ColourTable( inputStream,
imageDescriptor.LocalColourTableSize,
XmlDebugging );
WriteDebugXmlNode( _localColourTable.DebugXmlReader );
activeColourTable = _localColourTable; // make local table active
}
else
{
if( gct == null )
{
// We have neither local nor global colour table, so we
// won't be able to decode this frame.
Bitmap emptyBitmap = new Bitmap( lsd.LogicalScreenSize.Width,
lsd.LogicalScreenSize.Height );
_image = emptyBitmap;
_delay = gce.DelayTime;
SetStatus( ErrorState.FrameHasNoColourTable, "" );
return;
}
activeColourTable = gct; // make global table active
if( lsd.BackgroundColourIndex == transparentColourIndex )
{
backgroundColour = Color.FromArgb( 0 );
}
}
#endregion
// decode pixel data
int pixelCount = imageDescriptor.Size.Width * imageDescriptor.Size.Height;
TableBasedImageData indexedPixels
= new TableBasedImageData( inputStream, pixelCount, XmlDebugging );
WriteDebugXmlNode( indexedPixels.DebugXmlReader );
if( indexedPixels.Pixels.Count == 0 )
{
// TESTME: constructor - indexedPixels.Pixels.Count == 0
Bitmap emptyBitmap = new Bitmap( lsd.LogicalScreenSize.Width,
lsd.LogicalScreenSize.Height );
_image = emptyBitmap;
_delay = gce.DelayTime;
SetStatus( ErrorState.FrameHasNoImageData, "" );
WriteDebugXmlFinish();
return;
}
// Skip any remaining blocks up to the next block terminator (in
// case there is any surplus data before the next frame)
SkipBlocks( inputStream );
_indexedPixels = indexedPixels;
_extension = gce;
if( gce != null )
{
_delay = gce.DelayTime;
}
_imageDescriptor = imageDescriptor;
_backgroundColour = backgroundColour;
GifComponentStatus status;
_image = CreateBitmap( indexedPixels,
lsd,
imageDescriptor,
activeColourTable,
gce,
previousFrame,
previousFrameBut1,
out status );
WriteDebugXmlFinish();
}
public void ConstructorTestTooWide()
{
ReportStart();
int width = ushort.MaxValue + 1;
int height = 20;
Size screenSize = new Size( width, height );
bool hasGlobalColourTable = true;
int colourResolution = 6;
bool colourTableIsSorted = false;
int globalColourTableSizeBits = 3;
int backgroundColourIndex = 12;
int pixelAspectRatio = 2;
try
{
_lsd = new LogicalScreenDescriptor( screenSize,
hasGlobalColourTable,
colourResolution,
colourTableIsSorted,
globalColourTableSizeBits,
backgroundColourIndex,
pixelAspectRatio );
}
catch( ArgumentException ex )
{
string message
= "Logical screen width cannot be more than "
+ ushort.MaxValue + ". "
+ "Supplied value: " + width;
StringAssert.Contains( message, ex.Message );
Assert.AreEqual( "logicalScreenSize", ex.ParamName );
ReportEnd();
throw;
}
}
/// <summary>
/// Sets the pixels of the decoded image.
/// </summary>
/// <param name="imageData">
/// Table based image data containing the indices within the active
/// colour table of the colours of the pixels in this frame.
/// </param>
/// <param name="lsd">
/// The logical screen descriptor for the GIF stream.
/// </param>
/// <param name="id">
/// The image descriptor for this frame.
/// </param>
/// <param name="activeColourTable">
/// The colour table to use with this frame - either the global colour
/// table or a local colour table.
/// </param>
/// <param name="gce">
/// The graphic control extension, if any, which precedes this image in
/// the input stream.
/// </param>
/// <param name="previousFrame">
/// The frame which precedes this one in the GIF stream, if present.
/// </param>
/// <param name="previousFrameBut1">
/// The frame which precedes the frame before this one in the GIF stream,
/// if present.
/// </param>
/// <param name="status">
/// GifComponentStatus containing any errors which occurred during the
/// creation of the bitmap.
/// </param>
private static Bitmap CreateBitmap( TableBasedImageData imageData,
LogicalScreenDescriptor lsd,
ImageDescriptor id,
ColourTable activeColourTable,
GraphicControlExtension gce,
GifFrame previousFrame,
GifFrame previousFrameBut1,
out GifComponentStatus status )
{
status = new GifComponentStatus( ErrorState.Ok, "" );
Color[] pixelsForThisFrame = new Color[lsd.LogicalScreenSize.Width
* lsd.LogicalScreenSize.Height];
Bitmap baseImage = GetBaseImage( previousFrame,
previousFrameBut1,
lsd,
gce,
activeColourTable );
// copy each source line to the appropriate place in the destination
int pass = 1;
int interlaceRowIncrement = 8;
int interlaceRowNumber = 0; // the row of pixels we're currently
// setting in an interlaced image.
for( int i = 0; i < id.Size.Height; i++)
{
int pixelRowNumber = i;
if( id.IsInterlaced )
{
#region work out the pixel row we're setting for an interlaced image
if( interlaceRowNumber >= id.Size.Height )
{
pass++;
switch( pass )
{
case 2 :
interlaceRowNumber = 4;
break;
case 3 :
interlaceRowNumber = 2;
interlaceRowIncrement = 4;
break;
case 4 :
interlaceRowNumber = 1;
interlaceRowIncrement = 2;
break;
}
}
#endregion
pixelRowNumber = interlaceRowNumber;
interlaceRowNumber += interlaceRowIncrement;
}
// Colour in the pixels for this row
pixelRowNumber += id.Position.Y;
if( pixelRowNumber < lsd.LogicalScreenSize.Height )
{
int k = pixelRowNumber * lsd.LogicalScreenSize.Width;
int dx = k + id.Position.X; // start of line in dest
int dlim = dx + id.Size.Width; // end of dest line
if( (k + lsd.LogicalScreenSize.Width) < dlim )
{
// TESTME: CreateBitmap - past dest edge
dlim = k + lsd.LogicalScreenSize.Width; // past dest edge
}
int sx = i * id.Size.Width; // start of line in source
while (dx < dlim)
{
// map color and insert in destination
int indexInColourTable = (int) imageData.Pixels[sx++];
// Set this pixel's colour if its index isn't the
// transparent colour index, or if this frame doesn't
// have a transparent colour.
Color c;
if( gce.HasTransparentColour && indexInColourTable == gce.TransparentColourIndex )
{
c = Color.Empty; // transparent pixel
}
else
{
if( indexInColourTable < activeColourTable.Length )
{
c = activeColourTable[indexInColourTable];
}
else
{
// TESTME: CreateBitmap - BadColourIndex
c = Color.Black;
string message
= "Colour index: "
+ indexInColourTable
+ ", colour table length: "
+ activeColourTable.Length
+ " (" + dx + "," + pixelRowNumber + ")";
status = new GifComponentStatus( ErrorState.BadColourIndex,
message );
}
}
pixelsForThisFrame[dx] = c;
dx++;
}
}
}
return CreateBitmap( baseImage, pixelsForThisFrame );
}
public void WriteToStreamTest()
{
ReportStart();
Size screenSize = new Size( 12, 4 );
bool hasGlobalColourTable = false;
int colourResolution = 3;
bool globalColourTableIsSorted = true;
int globalColourTableSizeBits = 4;
int backgroundColourIndex = 2;
int pixelAspectRatio = 1;
_lsd = new LogicalScreenDescriptor( screenSize,
hasGlobalColourTable,
colourResolution,
globalColourTableIsSorted,
globalColourTableSizeBits,
backgroundColourIndex,
pixelAspectRatio );
MemoryStream s = new MemoryStream();
_lsd.WriteToStream( s );
s.Seek( 0, SeekOrigin.Begin );
_lsd = new LogicalScreenDescriptor( s );
Assert.AreEqual( ErrorState.Ok, _lsd.ConsolidatedState );
Assert.AreEqual( screenSize, _lsd.LogicalScreenSize );
Assert.AreEqual( hasGlobalColourTable, _lsd.HasGlobalColourTable );
Assert.AreEqual( colourResolution, _lsd.ColourResolution );
Assert.AreEqual( globalColourTableIsSorted, _lsd.GlobalColourTableIsSorted );
Assert.AreEqual( globalColourTableSizeBits, _lsd.GlobalColourTableSizeBits );
Assert.AreEqual( backgroundColourIndex, _lsd.BackgroundColourIndex );
Assert.AreEqual( pixelAspectRatio, _lsd.PixelAspectRatio );
ReportEnd();
}
/// <summary>
/// Checks whether the supplied logical screen descriptor matches that
/// returned by this class.
/// </summary>
/// <param name="lsd"></param>
internal static void CheckLogicalScreenDescriptor( LogicalScreenDescriptor lsd )
{
Assert.AreEqual( BackgroundColourIndex,
lsd.BackgroundColourIndex,
"BackgroundColourIndex" );
Assert.AreEqual( ColourResolution,
lsd.ColourResolution,
"ColourResolution" );
Assert.AreEqual( GlobalColourTableSize,
lsd.GlobalColourTableSize,
"GlobalColourTableSize" );
Assert.AreEqual( GlobalColourTableSizeBits,
lsd.GlobalColourTableSizeBits,
"GlobalColourTableSizeBits" );
Assert.AreEqual( HasGlobalColourTable,
lsd.HasGlobalColourTable,
"HasGlobalColourTable" );
Assert.AreEqual( LogicalScreenSize,
lsd.LogicalScreenSize,
"LogicalScreenSize" );
Assert.AreEqual( PixelAspectRatio,
lsd.PixelAspectRatio,
"PixelAspectRatio" );
Assert.AreEqual( GlobalColourTableIsSorted,
lsd.GlobalColourTableIsSorted,
"GlobalColourTableIsSorted" );
}
private void DecodeRotatingGlobe( bool xmlDebugging )
{
string fileName
= @"images\globe\spinning globe better 200px transparent background.gif";
_decoder = new GifDecoder( fileName, xmlDebugging );
WriteMessage( "Started decoding. XmlDebugging=" + xmlDebugging );
_decoder.Decode();
WriteMessage( "Finished decoding. XmlDebugging=" + xmlDebugging );
if( xmlDebugging )
{
Assert.AreEqual( ExpectedDebugXml, _decoder.DebugXml );
}
_lsd = _decoder.LogicalScreenDescriptor;
int expectedColourTableSize = 64;
Assert.AreEqual( ErrorState.Ok, _decoder.ConsolidatedState );
Assert.AreEqual( "GIF", _decoder.Header.Signature );
Assert.AreEqual( "89a", _decoder.Header.Version );
Assert.IsNotNull( _decoder.GlobalColourTable );
Assert.AreEqual( true, _lsd.HasGlobalColourTable );
Assert.AreEqual( expectedColourTableSize,
_lsd.GlobalColourTableSize );
Assert.AreEqual( expectedColourTableSize,
_decoder.GlobalColourTable.Length );
Assert.AreEqual( 2, _lsd.ColourResolution );
Assert.AreEqual( Color.FromArgb( 255, 255, 255, 255 ),
_decoder.BackgroundColour );
Assert.AreEqual( 63, _lsd.BackgroundColourIndex );
Assert.AreEqual( false, _lsd.GlobalColourTableIsSorted );
Assert.AreEqual( 200, _lsd.LogicalScreenSize.Width );
Assert.AreEqual( 191, _lsd.LogicalScreenSize.Height );
Assert.AreEqual( 0, _lsd.PixelAspectRatio );
Assert.AreEqual( 0, _decoder.NetscapeExtension.LoopCount );
Assert.AreEqual( ErrorState.Ok, _decoder.ErrorState );
Assert.AreEqual( 20, _decoder.Frames.Count );
int frameNumber = 0;
string frameId;
foreach( GifFrame thisFrame in _decoder.Frames )
{
frameId = "Frame " + frameNumber;
Assert.IsNull( thisFrame.LocalColourTable, frameId );
Assert.AreEqual( 10, thisFrame.Delay, frameId );
#region image descriptor tests
ImageDescriptor descriptor = thisFrame.ImageDescriptor;
Assert.AreEqual( false, descriptor.HasLocalColourTable, frameId );
Assert.AreEqual( 2,
descriptor.LocalColourTableSize,
frameId );
Assert.AreEqual( 200, descriptor.Size.Width, frameId );
Assert.AreEqual( 191, descriptor.Size.Height, frameId );
Assert.AreEqual( 0, descriptor.Position.X, frameId );
Assert.AreEqual( 0, descriptor.Position.Y, frameId );
Assert.AreEqual( false, descriptor.IsInterlaced, frameId );
Assert.AreEqual( false, descriptor.IsSorted, frameId );
#endregion
#region graphic control extension tests
GraphicControlExtension gce = thisFrame.GraphicControlExtension;
Assert.AreEqual( 4, gce.BlockSize, frameId );
Assert.AreEqual( 10, gce.DelayTime, frameId );
if( frameNumber == 19 )
{
Assert.AreEqual( DisposalMethod.DoNotDispose,
gce.DisposalMethod, frameId );
}
else
{
Assert.AreEqual( DisposalMethod.RestoreToBackgroundColour,
gce.DisposalMethod, frameId );
}
Assert.AreEqual( 63, gce.TransparentColourIndex, frameId );
Assert.IsTrue( gce.HasTransparentColour, frameId );
Assert.IsFalse( gce.ExpectsUserInput, frameId );
#endregion
frameNumber++;
}
CompareFrames( fileName );
}