1IJG JPEG LIBRARY:  FILE LIST
2
3Copyright (C) 1994-1997, Thomas G. Lane.
4This file is part of the Independent JPEG Group's software.
5For conditions of distribution and use, see the accompanying README file.
6
7
8Here is a road map to the files in the IJG JPEG distribution.  The
9distribution includes the JPEG library proper, plus two application
10programs ("cjpeg" and "djpeg") which use the library to convert JPEG
11files to and from some other popular image formats.  A third application
12"jpegtran" uses the library to do lossless conversion between different
13variants of JPEG.  There are also two stand-alone applications,
14"rdjpgcom" and "wrjpgcom".
15
16
17THE JPEG LIBRARY
18================
19
20Include files:
21
22jpeglib.h	JPEG library's exported data and function declarations.
23jconfig.h	Configuration declarations.  Note: this file is not present
24		in the distribution; it is generated during installation.
25jmorecfg.h	Additional configuration declarations; need not be changed
26		for a standard installation.
27jerror.h	Declares JPEG library's error and trace message codes.
28jinclude.h	Central include file used by all IJG .c files to reference
29		system include files.
30jpegint.h	JPEG library's internal data structures.
31jlossls.h	JPEG library's lossless codec data structures.
32jlossy.h	JPEG library's lossy codec structures.
33jchuff.h	Private declarations for Huffman encoder modules.
34jdhuff.h	Private declarations for Huffman decoder modules.
35jdct.h		Private declarations for forward & reverse DCT subsystems.
36jmemsys.h	Private declarations for memory management subsystem.
37jversion.h	Version information.
38
39Applications using the library should include jpeglib.h (which in turn
40includes jconfig.h and jmorecfg.h).  Optionally, jerror.h may be included
41if the application needs to reference individual JPEG error codes.  The
42other include files are intended for internal use and would not normally
43be included by an application program.  (cjpeg/djpeg/etc do use jinclude.h,
44since its function is to improve portability of the whole IJG distribution.
45Most other applications will directly include the system include files they
46want, and hence won't need jinclude.h.)
47
48
49C source code files:
50
51These files contain most of the functions intended to be called directly by
52an application program:
53
54jcapimin.c	Application program interface: core routines for compression.
55jcapistd.c	Application program interface: standard compression.
56jdapimin.c	Application program interface: core routines for decompression.
57jdapistd.c	Application program interface: standard decompression.
58jcomapi.c	Application program interface routines common to compression
59		and decompression.
60jcparam.c	Compression parameter setting helper routines.
61jctrans.c	API and library routines for transcoding compression.
62jdtrans.c	API and library routines for transcoding decompression.
63
64Compression side of the library:
65
66jcinit.c	Initialization: determines which other modules to use.
67jcmaster.c	Master control: setup and inter-pass sequencing logic.
68jcmainct.c	Main buffer controller (preprocessor => JPEG compressor).
69jchuff.c	Codec-independent Huffman entropy encoding routines.
70jcprepct.c	Preprocessor buffer controller.
71jccolor.c	Color space conversion.
72jcsample.c	Downsampling.
73jcmarker.c	JPEG marker writing.
74jdatadst.c	Data destination manager for stdio output.
75
76Lossy (DCT) codec:
77
78jlossy.c	Lossy compressor proper.
79jccoefct.c	Buffer controller for DCT coefficient buffer.
80jcdctmgr.c	DCT manager (DCT implementation selection & control).
81jfdctint.c	Forward DCT using slow-but-accurate integer method.
82jfdctfst.c	Forward DCT using faster, less accurate integer method.
83jfdctflt.c	Forward DCT using floating-point arithmetic.
84jcshuff.c	Huffman entropy coding for sequential JPEG.
85jcphuff.c	Huffman entropy coding for progressive JPEG.
86
87Lossless (spatial) codec:
88
89jclossls.c	Lossless compressor proper.
90jcdiffct.c	Buffer controller for difference buffer.
91jcscale.c	Point transformation.
92jcpred.c	Sample predictor and differencer.
93jclhuff.c	Huffman entropy encoding for lossless JPEG.
94
95Decompression side of the library:
96
97jdmaster.c	Master control: determines which other modules to use.
98jdinput.c	Input controller: controls input processing modules.
99jdmainct.c	Main buffer controller (JPEG decompressor => postprocessor).
100jdhuff.c	Codec-independent Huffman entropy decoding routines.
101jdpostct.c	Postprocessor buffer controller.
102jdmarker.c	JPEG marker reading.
103jdsample.c	Upsampling.
104jdcolor.c	Color space conversion.
105jdmerge.c	Merged upsampling/color conversion (faster, lower quality).
106jquant1.c	One-pass color quantization using a fixed-spacing colormap.
107jquant2.c	Two-pass color quantization using a custom-generated colormap.
108		Also handles one-pass quantization to an externally given map.
109jdatasrc.c	Data source manager for stdio input.
110
111Lossy (DCT) codec:
112
113jdlossy.c	Lossy decompressor proper.
114jdcoefct.c	Buffer controller for DCT coefficient buffer.
115jdshuff.c	Huffman entropy decoding for sequential JPEG.
116jdphuff.c	Huffman entropy decoding for progressive JPEG.
117jddctmgr.c	IDCT manager (IDCT implementation selection & control).
118jidctint.c	Inverse DCT using slow-but-accurate integer method.
119jidctfst.c	Inverse DCT using faster, less accurate integer method.
120jidctflt.c	Inverse DCT using floating-point arithmetic.
121jidctred.c	Inverse DCTs with reduced-size outputs.
122
123Lossless (spatial) codec:
124
125jdlossls.c	Lossless decompressor proper.
126jddiffct.c	Buffer controller for difference buffers.
127jdlhuff.c	Huffman entropy decoding for lossless JPEG.
128jdpred.c	Sample predictor and undifferencer.
129jdscale.c	Point transformation, sample size scaling.
130
131Support files for both compression and decompression:
132
133jerror.c	Standard error handling routines (application replaceable).
134jmemmgr.c	System-independent (more or less) memory management code.
135jcodec.c	Codec-independent utility routines.
136jutils.c	Miscellaneous utility routines.
137
138jmemmgr.c relies on a system-dependent memory management module.  The IJG
139distribution includes the following implementations of the system-dependent
140module:
141
142jmemnobs.c	"No backing store": assumes adequate virtual memory exists.
143jmemansi.c	Makes temporary files with ANSI-standard routine tmpfile().
144jmemname.c	Makes temporary files with program-generated file names.
145jmemdos.c	Custom implementation for MS-DOS (16-bit environment only):
146		can use extended and expanded memory as well as temp files.
147jmemmac.c	Custom implementation for Apple Macintosh.
148
149Exactly one of the system-dependent modules should be configured into an
150installed JPEG library (see install.doc for hints about which one to use).
151On unusual systems you may find it worthwhile to make a special
152system-dependent memory manager.
153
154
155Non-C source code files:
156
157jmemdosa.asm	80x86 assembly code support for jmemdos.c; used only in
158		MS-DOS-specific configurations of the JPEG library.
159
160
161CJPEG/DJPEG/JPEGTRAN
162====================
163
164Include files:
165
166cdjpeg.h	Declarations shared by cjpeg/djpeg/jpegtran modules.
167cderror.h	Additional error and trace message codes for cjpeg et al.
168transupp.h	Declarations for jpegtran support routines in transupp.c.
169
170C source code files:
171
172cjpeg.c		Main program for cjpeg.
173djpeg.c		Main program for djpeg.
174jpegtran.c	Main program for jpegtran.
175cdjpeg.c	Utility routines used by all three programs.
176rdcolmap.c	Code to read a colormap file for djpeg's "-map" switch.
177rdswitch.c	Code to process some of cjpeg's more complex switches.
178		Also used by jpegtran.
179transupp.c	Support code for jpegtran: lossless image manipulations.
180
181Image file reader modules for cjpeg:
182
183rdbmp.c		BMP file input.
184rdgif.c		GIF file input (now just a stub).
185rdppm.c		PPM/PGM file input.
186rdrle.c		Utah RLE file input.
187rdtarga.c	Targa file input.
188
189Image file writer modules for djpeg:
190
191wrbmp.c		BMP file output.
192wrgif.c		GIF file output (a mere shadow of its former self).
193wrppm.c		PPM/PGM file output.
194wrrle.c		Utah RLE file output.
195wrtarga.c	Targa file output.
196
197
198RDJPGCOM/WRJPGCOM
199=================
200
201C source code files:
202
203rdjpgcom.c	Stand-alone rdjpgcom application.
204wrjpgcom.c	Stand-alone wrjpgcom application.
205
206These programs do not depend on the IJG library.  They do use
207jconfig.h and jinclude.h, only to improve portability.
208
209
210ADDITIONAL FILES
211================
212
213Documentation (see README for a guide to the documentation files):
214
215README		Master documentation file.
216*.doc		Other documentation files.
217*.1		Documentation in Unix man page format.
218change.log	Version-to-version change highlights.
219example.c	Sample code for calling JPEG library.
220
221Configuration/installation files and programs (see install.doc for more info):
222
223configure	Unix shell script to perform automatic configuration.
224ltconfig	Support scripts for configure (from GNU libtool).
225ltmain.sh
226config.guess
227config.sub
228install-sh	Install shell script for those Unix systems lacking one.
229ckconfig.c	Program to generate jconfig.h on non-Unix systems.
230jconfig.doc	Template for making jconfig.h by hand.
231makefile.*	Sample makefiles for particular systems.
232jconfig.*	Sample jconfig.h for particular systems.
233ansi2knr.c	De-ANSIfier for pre-ANSI C compilers (courtesy of
234		L. Peter Deutsch and Aladdin Enterprises).
235
236Test files (see install.doc for test procedure):
237
238test*.*		Source and comparison files for confidence test.
239		These are binary image files, NOT text files.
240