| /* |
| * jdarith.c |
| * |
| * Copyright (C) 1991, Thomas G. Lane. |
| * This file is part of the Independent JPEG Group's software. |
| * For conditions of distribution and use, see the accompanying README file. |
| * |
| * This file contains arithmetic entropy decoding routines. |
| * These routines are invoked via the methods entropy_decode |
| * and entropy_decoder_init/term. |
| */ |
| |
| #include "jinclude.h" |
| |
| #ifdef ARITH_CODING_SUPPORTED |
| |
| |
| /* |
| * The arithmetic coding option of the JPEG standard specifies Q-coding, |
| * which is covered by patents held by IBM (and possibly AT&T and Mitsubishi). |
| * At this time it does not appear to be legal for the Independent JPEG |
| * Group to distribute software that implements arithmetic coding. |
| * We have therefore removed arithmetic coding support from the |
| * distributed source code. |
| * |
| * We're not happy about it either. |
| */ |
| |
| |
| /* |
| * The method selection routine for arithmetic entropy decoding. |
| */ |
| |
| GLOBAL void |
| jseldarithmetic (decompress_info_ptr cinfo) |
| { |
| if (cinfo->arith_code) { |
| ERREXIT(cinfo->emethods, "Sorry, there are legal restrictions on arithmetic coding"); |
| } |
| } |
| |
| #endif /* ARITH_CODING_SUPPORTED */ |
