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libsswf: sswf::TagImage Class Reference

The image class in SWF. More...

#include <libsswf.h>

Inheritance diagram for sswf::TagImage:

:TagBaseID :TagBase :MemoryManager

List of all members.

Public Types

enum  image_format_t {
 The list of formats available for the TagImage. More...

Public Member Functions

void GetImageData (image_t &image_data)
 Retrieve the current image information.
ErrorManager::error_code_t LoadJPEG (const char *filename, image_t &im)
 Load a JPEG image.
ErrorManager::error_code_t LoadTGA (const char *filename, image_t &im)
 Load a Targa image.
virtual ErrorManager::error_code_t Save (Data &data)
 Save the image in the specified Data buffer.
ErrorManager::error_code_t SaveJPEG (Data &encoding, Data &image)
 Save a JPEG in a set of Data buffers.
ErrorManager::error_code_t SetAlpha (image_t &im, const image_t &mask)
 Set the alpha channel of an image.
void SetDeblock (int deblock)
 Defines the deblock filter parameter for a JPEG.
ErrorManager::error_code_t SetFilename (const char *image, const char *mask)
 Load an image in the specified TagImage.
void SetFormat (image_format_t format)
 Set the required format for when the image is to be saved.
void SetImage (long width, long height, unsigned char *data, bool alpha=false, long count=0, unsigned char *colormap=0)
 Set an image in the TagImage object.
void SetQuality (int quality)
 Defines the quality level for a JPEG.
 TagImage (TagBase *parent)
 Initializes the TagImage object.
virtual swf_type_t TypeFlags (void) const
 Returns the flags defined for a TagImage.

Private Member Functions

virtual ErrorManager::error_code_t ParseTag (swf_tag_t tag, const Data &data)
virtual ErrorManager::error_code_t PreSave (void)
 Check that the image can be saved.

Private Attributes

unsigned char * f_colormap
long f_count
int f_deblock
image_format_t f_format
image_t f_image
int f_quality


struct  image_t
 Defines a bitmap. More...

Detailed Description

This class is used to include an image in an SWF animation. Images become fills in a style which is then rendered by a shape object.

SWF supports only two image formats: JPEG and Lossless (which is similar to PNG: a compressed bitmap using zlib.)

Older movies were constrained to one set of JPEG Tables and any number of DefineBitsJPEG. Newer movies can incorporate the JPEG Tables in the DefineBitsJPEG2. Also, since version 3, SWF supports DefineBitsJPEG3 that includes an alpha channel (compressed with zlib) for JPEG images.

Lossless images can also include an alpha channel. It supports different formats such as grey scales and paletted images. The library will automatically try to use a palette if possible (i.e. if your image is small or only uses a very limited number of colors.)

See also:
SWF Alexis' Reference—DefineJPEGTables

SWF Alexis' Reference—DefineBitsJPEG

SWF Alexis' Reference—DefineBitsJPEG2

SWF Alexis' Reference—DefineBitsJPEG3

SWF Alexis' Reference—DefineBitsLossless

SWF Alexis' Reference—DefineBitsLossless2

SWF Alexis' Reference—swf_tag

Member Enumeration Documentation

This enumeration lists all the possible formats supported by the SWF format. Note that does not define the image formats supported by the SSWF library.

IMAGE_FORMAT_UNKNOWN  By default the format of an image is set to Unknown.

This is the default format until you specifically call the sswf::TagImage::SetFormat() function.

The TagImage does not try to guess the output format for you (at least, not yet.)

IMAGE_FORMAT_LOSSLESS_BEST  Used to let the library select between the different lossless formats.

This format is a special internal format one can use to let the library choose between the different available lossless formats. This means the library will try all the different modes and choose the one which generates the smallest result.

See also:



IMAGE_FORMAT_LOSSLESS_8  Save a paletted image.

This format is not currently supported because we do not have a working quantization function.

The sswf::TagImage::IMAGE_FORMAT_LOSSLESS_BEST may make use of that format if it can transform the entire image to a paletted image.

See also:



IMAGE_FORMAT_LOSSLESS_16  Save a lossless image in 16 bits.

Save the image in a lossless 16 bits image. When the sswf::TagImage::IMAGE_FORMAT_LOSSLESS_BEST is used, it switches to the 16 bits format only if all the colors use only the 5 top bits (i.e. bits 0, 1 and 2 are all zeroes.)

The 16 bits image is really only 15 bits, 5 bits per component (xrrrrrgggggbbbbb).

See also:



IMAGE_FORMAT_LOSSLESS_32  Saves the Lossless image in 32 bits.

This format saves an RGB image in XRGB format and an ARGB image in ARGB format. When no alpha is saved it puts 0 everywhere.

See also:



IMAGE_FORMAT_JPEG  Saves the image compressed with JPEG.

This format requests that the TagImage be compressed using the JPEG format.

IMAGE_FORMAT_max  Maximum format number.

This definition is only to define the largest possible format.

Constructor & Destructor Documentation

TagImage::TagImage ( TagBase parent  ) 

This function initializes the image to all defaults.

This means no image, no alpha channel, default quality.

[in] parent The TagHeader in which this TagImage is to be inserted

References sswf::TagImage::image_t::f_alpha, f_colormap, f_count, sswf::TagImage::image_t::f_data, f_deblock, f_format, sswf::TagImage::image_t::f_height, f_image, f_quality, sswf::TagImage::image_t::f_width, and IMAGE_FORMAT_UNKNOWN.

Member Function Documentation

sswf::TagImage::GetImageData ( image_t image_data  )  [inline]

This function retrieves the image information. This is a direct copy of the image structure with the internal data pointer. Do not modify the pointer or free it.

[out] image_data An image structure
A copy of the internal image structure

References f_image.

ErrorManager::error_code_t TagImage::LoadJPEG ( const char *  filename,
image_t im 

This function loads and decompresses a JPEG image.

If you want to set an image in the TagImage, use SetFilename() instead.

This function does not call OnError(). It is expected that you will use SetFilename() which generates errors as required. Note that the function specifically returns ErrorManager::ERROR_CODE_UNKNOWN_FORMAT if the image does not look like a JPEG. Other errors means that either there was an I/O error or the JPEG is corrupted.
[in] filename The name of the file to be loaded
[in] im The bitmap structure where the image is loaded
An error code or ErrorManager::ERROR_CODE_NONE
See also:
sswf::TagImage::LoadTGA(const char *filename, image_t& im)

References sswf::ErrorManager::ERROR_CODE_INVALID_IMAGE, sswf::ErrorManager::ERROR_CODE_IO, sswf::ErrorManager::ERROR_CODE_NONE, sswf::ErrorManager::ERROR_CODE_UNKNOWN_FORMAT, sswf::TagImage::image_t::f_alpha, sswf::TagImage::image_t::f_data, sswf::TagImage::image_t::f_height, sswf::TagImage::image_t::f_width, sswf::MemoryManager::MemAlloc(), SSWF_JPG_ERROR::pub, SSWF_JPG_ERROR::setjmp_buffer, sswfFillInputBuffer(), sswfInitSource(), sswfJPEGError(), sswfResyncToRestart(), sswfSkipInputData(), and sswfTermSource().

Referenced by SetFilename().

virtual ErrorManager::error_code_t sswf::TagImage::ParseTag ( swf_tag_t  tag,
const Data data 
) [private, virtual]

Implements sswf::TagBase.

ErrorManager::error_code_t TagImage::PreSave ( void   )  [private, virtual]

This function makes sure that the image format was defined and depending on the format and whether it uses an alpha channel, decides whether the minimum version is 2 or 3.

An error code or ErrorManager::ERROR_CODE_NONE

Reimplemented from sswf::TagBase.

References sswf::ErrorManager::ERROR_CODE_NONE, sswf::ErrorManager::ERROR_CODE_UNSUPPORTED_IMAGE_FORMAT, sswf::TagImage::image_t::f_alpha, f_deblock, f_format, f_image, IMAGE_FORMAT_JPEG, IMAGE_FORMAT_LOSSLESS_16, IMAGE_FORMAT_LOSSLESS_32, IMAGE_FORMAT_LOSSLESS_BEST, sswf::TagBase::MinimumVersion(), and sswf::TagBase::OnError().

ErrorManager::error_code_t TagImage::SaveJPEG ( Data encoding,
Data image 

This function saves a JPEG image table encodings and compressed bits in two Data buffers.

[in] encoding Save the JPEG tables in this Data buffer
[in] image Save the JPEG compressed bits in this Data buffer
An error or ErrorManager::ERROR_CODE_NONE

References sswf::ErrorManager::ERROR_CODE_JPEG, sswf::ErrorManager::ERROR_CODE_NONE, sswf::TagImage::image_t::f_data, sswf::TagImage::image_t::f_height, f_image, f_quality, sswf::TagImage::image_t::f_width, sswf::MemoryManager::MemAlloc(), sswf::MemoryManager::MemFree(), sswf::TagBase::OnError(), SSWF_JPG_ERROR::pub, SSWF_JPG_ERROR::setjmp_buffer, sswfEmptyOutputBuffer(), sswfInitDestination(), sswfJPEGError(), and sswfTermDestination().

Referenced by Save().

ErrorManager::error_code_t TagImage::SetAlpha ( image_t im,
const image_t mask 

This function takes an image and a mask as input and copy the mask in the alpha channel of the image.

The function works only if both images are exactly of the same size (i.e. same width and height.)

[in] im The image receiving the mask as its alpha channel
[in] mask The image used as the alpha channel
An error code or ErrorManager::ERROR_CODE_NONE

References sswf::ErrorManager::ERROR_CODE_NONE, sswf::ErrorManager::ERROR_CODE_SIZE_MISMATCH, sswf::TagImage::image_t::f_alpha, sswf::TagImage::image_t::f_data, sswf::TagImage::image_t::f_height, sswf::TagImage::image_t::f_width, and sswf::TagBase::OnError().

Referenced by SetFilename().

sswf::TagImage::SetDeblock ( int  deblock  )  [inline]

When displaying an image using the JPEG format, one can choose the deblock filter parameter. This is done with this function.

The deblocking is a number from 0 to 256. (An 8.8 fixed value of 0.0 to 1.0)

[in] deblock The deblocking filter parameter used to display the JPEG image.

References f_deblock.

sswf::TagImage::SetFormat ( image_format_t  format  )  [inline]

This function setst the format that the TagImage will use when saving the image.

The possible formats are:

The IMAGE_FORMAT_LOSSLESS_BEST format is used to let the system choose between the different LOSSLESS formats. It is lossless meaning that the best to ensure the smallest possible image is used without losing even one pixel (which often means using LOSSLESS 32.)

[in] format One of the IMAGE_FORMAT_...

References f_format.

void TagImage::SetImage ( long  width,
long  height,
unsigned char *  data,
bool  alpha = false,
long  count = 0,
unsigned char *  colormap = 0 

This function saves the specified image in the TagImage object.

The image is specified by all of its characteristics: width, height, buffer (data), whether it includes an alpha channel and whether it has a colormap.

The data pointer is saved as is in the image structure. This means the TagImage becomes the owner of that pointer. It will automatically free it with a call to MemFree().

It is expected that you use your image memory allocator to allocate this buffer:

        TagImage my_image;

        data = my_image->MemAlloc(width * height * 4, "My Image");
        // MemFree(data) -- done by the TagImage destructor when necessary

The colormap parameter is currently ignored.
[in] width The width of the image
[in] height The height of the image
[in] data The pointer to the data buffer (ARGB)
[in] alpha Whether the alpha channel is valid
[in] count The size of the colormap
[in] colormap The colors in the colormap (RGBA)

References sswf::TagImage::image_t::f_alpha, f_colormap, f_count, sswf::TagImage::image_t::f_data, sswf::TagImage::image_t::f_height, f_image, sswf::TagImage::image_t::f_width, and sswf::MemoryManager::MemClean().

sswf::TagImage::SetQuality ( int  quality  )  [inline]

When saving an image using the JPEG format, one can choose the quality of the image. This is done with this function.

The quality is a number from 0 to 100.

[in] quality The quality used to compress the image to a JPEG

References f_quality.

TagBase::swf_type_t TagImage::TypeFlags ( void   )  const [virtual]

This function defines the type flags for a tag image.

It is a definition and it has an identifier.


Implements sswf::TagBase.


Member Data Documentation

unsigned char* sswf::TagImage::f_colormap [private]

Referenced by SetFilename(), SetImage(), and TagImage().

long sswf::TagImage::f_count [private]

Referenced by SetFilename(), SetImage(), and TagImage().

Referenced by PreSave(), Save(), SetDeblock(), and TagImage().

Referenced by SaveJPEG(), SetQuality(), and TagImage().

The documentation for this class was generated from the following files:

Generated on Wed Mar 18 15:13:59 2009 for libsswf by  doxygen 1.5.5