From 3417567558ed1e3cea8bf67f67d56d3c9c4002a9 Mon Sep 17 00:00:00 2001 From: Thomas Vander Stichele Date: Sun, 23 Dec 2001 20:21:20 +0000 Subject: more fixes Original commit message from CVS: more fixes --- gst-libs/gst/idct/README | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) create mode 100644 gst-libs/gst/idct/README (limited to 'gst-libs/gst/idct/README') diff --git a/gst-libs/gst/idct/README b/gst-libs/gst/idct/README new file mode 100644 index 00000000..600f3da9 --- /dev/null +++ b/gst-libs/gst/idct/README @@ -0,0 +1,48 @@ +This archive contains a quick & dirty implementation of the IEEE Standard +1180-1990 accuracy test for inverse DCT. It is not guaranteed to be +correct ... but if you find any bugs, please let me know (by email to +tgl@cs.cmu.edu). + +The test harness consists of the C program ieeetest.c and shell script +doieee. For comparison purposes I have also supplied a copy of jrevdct.c, +the inverse DCT routine from release 4 of the Independent JPEG Group's +free JPEG software. (jrevdct.c is slightly modified from the IJG release +so that it will compile without the IJG include files.) jrevdct.c passes +the 1180 test --- or at least, this program thinks so. jrevdct.out is +the output from a test run. + +Note that numerical results may vary somewhat across machines. This appears +to be mostly due to differing results from the cosine function. + + +INSTALLATION: + Check the Makefile, change CC and CFLAGS if needed. Then say "make". +If your C compiler is non-ANSI, you may need to change includes and/or +function headers. + + To test a different IDCT routine, link with that routine instead of +jrevdct.o. You will need to modify dct.h and/or ieeetest.c if your +routine's calling convention is not in-place modification of an array +of 64 "short"s. + + +USAGE: + The standard test procedure is + doieee ieeetest >outputfile +Expect it to take a while (almost 80 minutes on my old 68030 box). +Each of the six passes will emit a row of 100 dots as it runs. + +You can grep the output for the word FAILS if you just want to know +yea or nay. + + +LEGAL MUMBO-JUMBO: + I hereby release the test harness to the public domain. + Thomas G. Lane, 22 Nov 1993 + +IMPORTANT: jrevdct.c is NOT public domain, but is copyrighted free software +(not the same thing at all). It is subject to IJG's distribution terms, which +primarily state that if you incorporate it into a program you must acknowledge +IJG's contribution in your program documentation. For more details and the +complete IJG software, see the IJG FTP archive at ftp.uu.net, in directory +/graphics/jpeg. -- cgit v1.2.1