From 9481014305ab8f8e1ba07749c0b7f68ec4b99e56 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Tue, 20 Feb 2007 12:43:58 +0100 Subject: Add livavcodec resampler plugin Add a new pcm_rate plugin, "lavcrate", that uses the resampling filter from libavcodec. It should provide high performance and good output quality. Add a documentation file for lavcrate. Update autoconf and automake to build lavcrate. From: Nicholas Kain --- rate-lavc/gcd.h | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+) create mode 100644 rate-lavc/gcd.h (limited to 'rate-lavc/gcd.h') diff --git a/rate-lavc/gcd.h b/rate-lavc/gcd.h new file mode 100644 index 0000000..672084c --- /dev/null +++ b/rate-lavc/gcd.h @@ -0,0 +1,56 @@ +/* + * Fast implementation of greatest common divisor using the binary algorithm. + * Copyright (c) 2007 Nicholas Kain + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to + * deal in the Software without restriction, including without limitation the + * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or + * sell copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS + * IN THE SOFTWARE. + */ + +/* computes gcd using binary algorithm */ +static int gcd(int a, int b) +{ + int s,d; + + if (!a || !b) + return a | b; + + for (s=0; ((a|b)&1) == 0; ++s) { + a >>= 1; + b >>= 1; + } + + while ((a&1) == 0) + a >>= 1; + + do { + while ((b&1) == 0) { + b >>= 1; + } + if (a>= 1; + } while (b); + + return a << s; +} + -- cgit