From 85990140e7302d1e7fcc9fc0eea316178c19fe03 Mon Sep 17 00:00:00 2001 From: Alexandra Hájková Date: Thu, 3 Dec 2015 13:45:10 +0100 Subject: dca: Add math helpers. They will be used by the integer core decoder. --- libavcodec/dcamath.h | 42 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) create mode 100644 libavcodec/dcamath.h (limited to 'libavcodec/dcamath.h') diff --git a/libavcodec/dcamath.h b/libavcodec/dcamath.h new file mode 100644 index 0000000000..e21eb075fb --- /dev/null +++ b/libavcodec/dcamath.h @@ -0,0 +1,42 @@ +/* + * This file is part of Libav. + * + * Libav is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * Libav is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with Libav; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include "libavutil/common.h" + + +// clip a signed integer into the (-2^23), (2^23-1) range +static inline int dca_clip23(int a) +{ + return av_clip_intp2(a, 23); +} + +static inline int32_t dca_norm(int64_t a, int bits) +{ + if (bits > 0) + return (int32_t)((a + (INT64_C(1) << (bits - 1))) >> bits); + else + return (int32_t)a; +} + +static inline int64_t dca_round(int64_t a, int bits) +{ + if (bits > 0) + return (a + (INT64_C(1) << (bits - 1))) & ~((INT64_C(1) << bits) - 1); + else + return a; +} -- cgit v1.2.3