3.1.1 jpeg-turbo/jpeg-turbo.asd

Source

jpeg-turbo.asd.

Parent Component

jpeg-turbo (system).

ASDF Systems

jpeg-turbo.

3.1.2 jpeg-turbo/src/package.lisp

Source

jpeg-turbo.asd.

Parent Component

jpeg-turbo (system).

Packages

jpeg-turbo.

3.1.3 jpeg-turbo/src/grovel.lisp

Dependency

src/package.lisp (file).

Source

jpeg-turbo.asd.

Parent Component

jpeg-turbo (system).

3.1.4 jpeg-turbo/src/jpeg-turbo.lisp

Dependency

src/grovel.lisp (file).

Source

jpeg-turbo.asd.

Parent Component

jpeg-turbo (system).

Public Interface

• compress (function).
• compress-to-octets (function).
• decompress (function).
• decompress-from-octets (function).
• decompress-header (function).
• decompress-header-from-octets (function).
• jpeg-error (condition).
• scaling-factors (function).
• with-compressor (macro).
• with-decompressor (macro).

Internals

• *pixel-sizes* (special variable).
• buf-size% (function).
• destroy-handle% (function).
• init-compress% (function).
• init-decompress% (function).
• jpeg-error-string (reader method).
• last-error (function).
• pixel-size (function).
• scale (function).
• scaling-factor-tclass (class).

5.1.1 Macros

Macro: with-compressor ((handle) &body body) ¶

Execute the macro’s body in the lexical scope of created compressor handle @c(handle). The handle is safely freed after use.

Package

jpeg-turbo.

Source

src/jpeg-turbo.lisp.

Macro: with-decompressor ((handle) &body body) ¶

Execute the macro’s body in the lexical scope of created decompressor handle @c(handle). The handle is safely freed after use.

Package

jpeg-turbo.

Source

src/jpeg-turbo.lisp.

5.1.2 Ordinary functions

Function: compress (handle filename array width height pixel-format &key quality subsamp flags) ¶

Compress an image to jpeg format and write it to file with the name @c(filename). See @c(compress-to-octets) for more info.

Package

jpeg-turbo.

Source

src/jpeg-turbo.lisp.

Function: compress-to-octets (handle array width height pixel-format &key quality subsamp flags) ¶

Compress an image to jpeg format. @c(handle) is a compressor handle created with @c(with-compressor). @c(array) is a simple array of @c((unsigned-byte 8)) values containing pixel data. Values of @c(pixel-format) described in section @ref[id=pf](pixel
formats). @c(quality) is an integer from 1 to 100. Higher values mean better quality. @c(subsamp) is described in @ref[id=subsamp](subsampling) section and @c(flags) in @ref[id=flags](flags) section.

Package

jpeg-turbo.

Source

src/jpeg-turbo.lisp.

Function: decompress (handle filename &key scaling-factor pixel-format flags) ¶

Decompress an image directly from file with the name @c(filename). See @c(decompress-from-octets) for more info

Package

jpeg-turbo.

Source

src/jpeg-turbo.lisp.

Function: decompress-from-octets (handle array &key scaling-factor pixel-format flags) ¶

Decompress a jpeg image. @c(handle) is a decompressor handle created with @c(with-decompressor). @c(array) is a simple array of @c((unsigned-byte 8)) values containing a compressed image. If @c(pixel-format) is specified, @c(libjpeg-turbo) converts output pixel format to a specified value. For the values of @c(pixel-format) see the section @ref[id=pf](pixel formats). For more information about @c(flags) see the section @ref[id=flags](flags). If @c(scaling-factor) is specified @c(librurbo-jpeg) will scale the output image to this scaling factor. Possible values are returned by @c(scaling-factors).

Return a decompressed image as a simple-array of @c((unsigned-byte 8)) value in the same manner as @c(cl-jpeg) does.

Package

jpeg-turbo.

Source

src/jpeg-turbo.lisp.

Function: decompress-header (handle filename) ¶

This is function is like @c(decompress-header-from-octets) but reads compressed image directly from file with the name @c(filename).

Package

jpeg-turbo.

Source

src/jpeg-turbo.lisp.

Function: decompress-header-from-octets (handle array) ¶

Decompress header of an image. @c(handle) must be a handle to decompressor created with @c(with-decompressor). @c(array) must be a simple array of @c((unsigned-byte 8)) values containing compressed jpeg image. Function returns four values:
@begin(enum)
@item(Width of an image.)
@item(Height of an image.)
@item(Chroma subsampling. See @ref[id=subsamp](subsampling) section.) @item(Colorspace. See @ref[id=cs](colorspaces) section.) @end(enum)

Package

jpeg-turbo.

Source

src/jpeg-turbo.lisp.

Function: scaling-factors () ¶

Return scaling factors supported by @c(libjpeg-turbo)

Package

jpeg-turbo.

Source

src/jpeg-turbo.lisp.

5.1.3 Conditions

Condition: jpeg-error ¶

Errors returned by libjpeg-turbo

Package

jpeg-turbo.

Source

src/jpeg-turbo.lisp.

Direct superclasses

error.

Direct methods

jpeg-error-string.

Direct slots

Slot: error-string ¶

Initargs

:error-string

Readers

jpeg-error-string.

Writers

This slot is read-only.

5.2.1 Special variables

Special Variable: *pixel-sizes* ¶

Size of a pixel in bytes for each pixel format

Package

jpeg-turbo.

Source

src/jpeg-turbo.lisp.

5.2.2 Ordinary functions

Function: buf-size% (width height subsamp) ¶

Package

jpeg-turbo.

Source

src/jpeg-turbo.lisp.

Function: destroy-handle% (handle) ¶

Package

jpeg-turbo.

Source

src/jpeg-turbo.lisp.

Function: init-compress% () ¶

Initialize jpeg compressor returning a handle to it. The handle must be freed with @c(destroy-handle%) after use. Use @c(with-compressor) macro instead of this function.

Package

jpeg-turbo.

Source

src/jpeg-turbo.lisp.

Function: init-decompress% () ¶

Initialize decompressor handle or signal an error. The handle must be destroyed after use with @c(destroy-handle%). It’s preferred to use @c(with-decompressor) macro which safely destroys the handle in the case of an error instead of this function.

Package

jpeg-turbo.

Source

src/jpeg-turbo.lisp.

Function: last-error (handle) ¶

Package

jpeg-turbo.

Source

src/jpeg-turbo.lisp.

Function: pixel-size (pixel-format) ¶

Package

jpeg-turbo.

Source

src/jpeg-turbo.lisp.

Function: scale (x scaling) ¶

Package

jpeg-turbo.

Source

src/jpeg-turbo.lisp.

5.2.3 Generic functions

Generic Reader: jpeg-error-string (condition) ¶

Package

jpeg-turbo.

Methods

Reader Method: jpeg-error-string ((condition jpeg-error)) ¶

Source

src/jpeg-turbo.lisp.

Target Slot

error-string.

5.2.4 Classes

Class: scaling-factor-tclass ¶

Package

jpeg-turbo.

Source

src/jpeg-turbo.lisp.

Direct superclasses

• foreign-struct-type.
• translatable-foreign-type.