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diff --git a/3rdparty/libjpeg/cdaltui.txt b/3rdparty/libjpeg/cdaltui.txt new file mode 100644 index 00000000000..702999fc1a5 --- /dev/null +++ b/3rdparty/libjpeg/cdaltui.txt @@ -0,0 +1,138 @@ +IJG JPEG LIBRARY: ALTERNATE USER INTERFACE FOR CJPEG/DJPEG + +Copyright (C) 2020, Guido Vollbeding. +This file is part of the Independent JPEG Group's software. +For conditions of distribution and use, see the accompanying README file. + + +There is an alternate command-line user interface for the IJG JPEG software. +It is designed for use under MS-DOS, and may also be useful on other non-Unix +operating systems. (For that matter, this code works fine on Unix, but the +standard command-line syntax is better on Unix because it is pipe-friendly.) + +With this user interface, cjpeg and djpeg accept multiple input file names +on the command line; output file names are generated by substituting +appropriate extensions. The user is prompted before any already-existing +file will be overwritten. + +Expansion of wild-card file specifications is useful but is not directly +provided by this code. Most DOS C compilers have the ability to do wild-card +expansion "behind the scenes", and we rely on that feature. On other systems, +the shell may do it for you, as is done on Unix. + +Also, a DOS-specific routine is provided to determine available memory; +this makes the -maxmemory switch unnecessary except in unusual cases. +If you know how to determine available memory on a different system, +you can easily add the necessary code. (And please send it along to +jpeg-info@jpegclub.org so we can include it in future releases!) + + +INSTALLATION +============ + +Rename the standard cjpeg.c file to cjpegstd.c, then rename cjpegalt.c to +cjpeg.c. +Rename the standard djpeg.c file to djpegstd.c, then rename djpegalt.c to +djpeg.c. +Then build the software as described in install.txt, with these exceptions: + +* Define PROGRESS_REPORT in jconfig.h if you want the percent-done display. +* Define NO_OVERWRITE_CHECK if you *don't* want overwrite confirmation. +* You may ignore the USE_SETMODE and TWO_FILE_COMMANDLINE symbols discussed + in install.txt; these files do not use them. +* As given, djpegalt.c defaults to BMP output (not PPM output as in the + standard djpeg.c). If you want something different, modify DEFAULT_FMT. + +You may also need to do something special to enable filename wild-card +expansion, assuming your compiler has that capability at all. + +Modify the standard usage.txt file as described below. (If you want to use +the Unix-style manual pages cjpeg.1 and djpeg.1, better fix them too.) + +To restore the standard user interface: +Rename cjpeg.c to cjpegalt.c, then rename cjpegstd.c to cjpeg.c. +Rename djpeg.c to djpegalt.c, then rename djpegstd.c to djpeg.c. +Then recompile/rebuild. + + +Here are some specific notes for popular MS-DOS compilers: + +Borland C: + Add "-DMSDOS" to CFLAGS to enable use of the DOS memory determination code. + Link with the standard library file WILDARGS.OBJ to get wild-card expansion. + +Microsoft C: + Add "-DMSDOS" to CFLAGS to enable use of the DOS memory determination code. + Link with the standard library file SETARGV.OBJ to get wild-card expansion. + In the versions I've used, you must also add /NOE to the linker switches to + avoid a duplicate-symbol error from including SETARGV. + +DJGPP (we recommend version 2.0 or later): + Add "-DFREE_MEM_ESTIMATE=0" to CFLAGS. Wild-card expansion is automatic. + + +USAGE +===== + +Most of the standard usage.txt file also applies to the alternate version, +but replace its "GENERAL USAGE" section with the text below. Edit the text +as necessary if you don't support wildcards or overwrite checking. Be sure +to fix the djpeg switch descriptions if you are not defaulting to PPM output. +Also, if you've provided an accurate memory-estimation procedure, you can +probably eliminate the HINTS related to the -maxmemory switch. + + +GENERAL USAGE + +We provide two programs, cjpeg to compress an image file into JPEG format, +and djpeg to decompress a JPEG file back into a conventional image format. + +The basic command line is: + cjpeg [switches] list of image files +or + djpeg [switches] list of jpeg files + +Each file named is compressed or decompressed. The input file(s) are not +modified; the output data is written to files which have the same names +except for extension. cjpeg always uses ".jpg" for the output file name's +extension; djpeg uses one of ".bmp", ".gif", ".ppm", ".rle", or ".tga", +depending on what output format is selected by the switches. + +For example, to convert xxx.bmp to xxx.jpg and yyy.ppm to yyy.jpg, say: + cjpeg xxx.bmp yyy.ppm + +On most systems you can use standard wildcards to specify the list of input +files; for example, on DOS "djpeg *.jpg" decompresses all the JPEG files in +the current directory. + +If an intended output file already exists, you'll be asked whether or not to +overwrite it. If you say no, the program skips that input file and goes on +to the next one. + +You can intermix switches and file names; for example + djpeg -gif file1.jpg -targa file2.jpg +decompresses file1.jpg into GIF format (file1.gif) and file2.jpg into Targa +format (file2.tga). Only switches to the left of a given file name affect +processing of that file; when there are conflicting switches, the rightmost +one takes precedence. + +You can override the program's choice of output file name by using the +-outfile switch, as in + cjpeg -outfile output.jpg input.ppm +-outfile only affects the first input file name to its right. + +The currently supported image file formats are: PPM (PBMPLUS color format), +PGM (PBMPLUS grayscale format), BMP, GIF, Targa, and RLE (Utah Raster Toolkit +format). (RLE is supported only if the URT library is available, which it +isn't on most non-Unix systems.) cjpeg recognizes the input image format +automatically, with the exception of some Targa-format files. You have to +tell djpeg which format to generate. + +JPEG files are in the standard JFIF file format. There are other, +less widely used JPEG-based file formats, but we don't support them. + +All switch names may be abbreviated; for example, -grayscale may be written +-gray or -gr. Most of the "basic" switches can be abbreviated to as little as +one letter. Upper and lower case are equivalent (-BMP is the same as -bmp). +British spellings are also accepted (e.g., -greyscale), though for brevity +these are not mentioned below. |