19c791cdac
With rare exceptions ...
- Always separate line continuation characters by one space from
preceding code.
- Always use two-space indentation. Never use tabs.
- Always use K&R-style conditional blocks.
- Always surround operators with spaces, except in raw assembly code.
- Always put a space after, but not before, a comma.
- Never put a space between type casts and variables/function calls.
- Never put a space between the function name and the argument list in
function declarations and prototypes.
- Always surround braces ('{' and '}') with spaces.
- Always surround statements (if, for, else, catch, while, do, switch)
with spaces.
- Always attach pointer symbols ('*' and '**') to the variable or
function name.
- Always precede pointer symbols ('*' and '**') by a space in type
casts.
- Use the MIN() macro from jpegint.h within the libjpeg and TurboJPEG
API libraries (using min() from tjutil.h is still necessary for
TJBench.)
- Where it makes sense (particularly in the TurboJPEG code), put a blank
line after variable declaration blocks.
- Always separate statements in one-liners by two spaces.
The purpose of this was to ease maintenance on my part and also to make
it easier for contributors to figure out how to format patch
submissions. This was admittedly confusing (even to me sometimes) when
we had 3 or 4 different style conventions in the same source tree. The
new convention is more consistent with the formatting of other OSS code
bases.
This commit corrects deviations from the chosen formatting style in the
libjpeg API code and reformats the TurboJPEG API code such that it
conforms to the same standard.
NOTES:
- Although it is no longer necessary for the function name in function
declarations to begin in Column 1 (this was historically necessary
because of the ansi2knr utility, which allowed libjpeg to be built
with non-ANSI compilers), we retain that formatting for the libjpeg
code because it improves readability when using libjpeg's function
attribute macros (GLOBAL(), etc.)
- This reformatting project was accomplished with the help of AStyle and
Uncrustify, although neither was completely up to the task, and thus
a great deal of manual tweaking was required. Note to developers of
code formatting utilities: the libjpeg-turbo code base is an
excellent test bed, because AFAICT, it breaks every single one of the
utilities that are currently available.
- The legacy (MMX, SSE, 3DNow!) assembly code for i386 has been
formatted to match the SSE2 code (refer to
ff5685d5344273df321eb63a005eaae19d2496e3.) I hadn't intended to
bother with this, but the Loongson MMI implementation demonstrated
that there is still academic value to the MMX implementation, as an
algorithmic model for other 64-bit vector implementations. Thus, it
is desirable to improve its readability in the same manner as that of
the SSE2 implementation.
104 lines
2.6 KiB
Groff
104 lines
2.6 KiB
Groff
.TH WRJPGCOM 1 "15 June 1995"
|
|
.SH NAME
|
|
wrjpgcom \- insert text comments into a JPEG file
|
|
.SH SYNOPSIS
|
|
.B wrjpgcom
|
|
[
|
|
.B \-replace
|
|
]
|
|
[
|
|
.BI \-comment " text"
|
|
]
|
|
[
|
|
.BI \-cfile " name"
|
|
]
|
|
[
|
|
.I filename
|
|
]
|
|
.LP
|
|
.SH DESCRIPTION
|
|
.LP
|
|
.B wrjpgcom
|
|
reads the named JPEG/JFIF file, or the standard input if no file is named,
|
|
and generates a new JPEG/JFIF file on standard output. A comment block is
|
|
added to the file.
|
|
.PP
|
|
The JPEG standard allows "comment" (COM) blocks to occur within a JPEG file.
|
|
Although the standard doesn't actually define what COM blocks are for, they
|
|
are widely used to hold user-supplied text strings. This lets you add
|
|
annotations, titles, index terms, etc to your JPEG files, and later retrieve
|
|
them as text. COM blocks do not interfere with the image stored in the JPEG
|
|
file. The maximum size of a COM block is 64K, but you can have as many of
|
|
them as you like in one JPEG file.
|
|
.PP
|
|
.B wrjpgcom
|
|
adds a COM block, containing text you provide, to a JPEG file.
|
|
Ordinarily, the COM block is added after any existing COM blocks; but you
|
|
can delete the old COM blocks if you wish.
|
|
.SH OPTIONS
|
|
Switch names may be abbreviated, and are not case sensitive.
|
|
.TP
|
|
.B \-replace
|
|
Delete any existing COM blocks from the file.
|
|
.TP
|
|
.BI \-comment " text"
|
|
Supply text for new COM block on command line.
|
|
.TP
|
|
.BI \-cfile " name"
|
|
Read text for new COM block from named file.
|
|
.PP
|
|
If you have only one line of comment text to add, you can provide it on the
|
|
command line with
|
|
.BR \-comment .
|
|
The comment text must be surrounded with quotes so that it is treated as a
|
|
single argument. Longer comments can be read from a text file.
|
|
.PP
|
|
If you give neither
|
|
.B \-comment
|
|
nor
|
|
.BR \-cfile,
|
|
then
|
|
.B wrjpgcom
|
|
will read the comment text from standard input. (In this case an input image
|
|
file name MUST be supplied, so that the source JPEG file comes from somewhere
|
|
else.) You can enter multiple lines, up to 64KB worth. Type an end-of-file
|
|
indicator (usually control-D) to terminate the comment text entry.
|
|
.PP
|
|
.B wrjpgcom
|
|
will not add a COM block if the provided comment string is empty. Therefore
|
|
\fB\-replace \-comment ""\fR can be used to delete all COM blocks from a file.
|
|
.SH EXAMPLES
|
|
.LP
|
|
Add a short comment to in.jpg, producing out.jpg:
|
|
.IP
|
|
.B wrjpgcom \-c
|
|
\fI"View of my back yard" in.jpg
|
|
.B >
|
|
.I out.jpg
|
|
.PP
|
|
Attach a long comment previously stored in comment.txt:
|
|
.IP
|
|
.B wrjpgcom
|
|
.I in.jpg
|
|
.B <
|
|
.I comment.txt
|
|
.B >
|
|
.I out.jpg
|
|
.PP
|
|
or equivalently
|
|
.IP
|
|
.B wrjpgcom
|
|
.B -cfile
|
|
.I comment.txt
|
|
.B <
|
|
.I in.jpg
|
|
.B >
|
|
.I out.jpg
|
|
.SH SEE ALSO
|
|
.BR cjpeg (1),
|
|
.BR djpeg (1),
|
|
.BR jpegtran (1),
|
|
.BR rdjpgcom (1)
|
|
.SH AUTHOR
|
|
Independent JPEG Group
|