Move fixed-point parts of the AC-3 encoder to separate files.

Originally committed as revision 26206 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/Makefile

@@ -54,7 +54,7 @@ OBJS-$(CONFIG_AAC_ENCODER)             += aacenc.o aaccoder.o    \
                                           mpeg4audio.o
 OBJS-$(CONFIG_AASC_DECODER)            += aasc.o msrledec.o
 OBJS-$(CONFIG_AC3_DECODER)             += ac3dec.o ac3dec_data.o ac3.o
-OBJS-$(CONFIG_AC3_ENCODER)             += ac3enc.o ac3tab.o ac3.o
+OBJS-$(CONFIG_AC3_ENCODER)             += ac3enc_fixed.o ac3tab.o ac3.o
 OBJS-$(CONFIG_ALAC_DECODER)            += alac.o
 OBJS-$(CONFIG_ALAC_ENCODER)            += alacenc.o
 OBJS-$(CONFIG_ALS_DECODER)             += alsdec.o bgmc.o mpeg4audio.o

libavcodec/ac3enc_fixed.h

+/*
+ * The simplest AC-3 encoder
+ * Copyright (c) 2000 Fabrice Bellard
+ * Copyright (c) 2006-2010 Justin Ruggles <justin.ruggles@gmail.com>
+ * Copyright (c) 2006-2010 Prakash Punnoor <prakash@punnoor.de>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg 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.
+ *
+ * FFmpeg 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 FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file
+ * fixed-point AC-3 encoder header.
+ */
+
+#ifndef AVCODEC_AC3ENC_FIXED_H
+#define AVCODEC_AC3ENC_FIXED_H
+
+#include <stdint.h>
+
+
+typedef int16_t SampleType;
+typedef int32_t CoefType;
+
+#define SCALE_COEF(a) (a)
+
+
+/**
+ * Compex number.
+ * Used in fixed-point MDCT calculation.
+ */
+typedef struct IComplex {
+    int16_t re,im;
+} IComplex;
+
+typedef struct AC3MDCTContext {
+    const int16_t *window;                  ///< MDCT window function
+    int nbits;                              ///< log2(transform size)
+    int16_t *costab;                        ///< FFT cos table
+    int16_t *sintab;                        ///< FFT sin table
+    int16_t *xcos1;                         ///< MDCT cos table
+    int16_t *xsin1;                         ///< MDCT sin table
+    int16_t *rot_tmp;                       ///< temp buffer for pre-rotated samples
+    IComplex *cplx_tmp;                     ///< temp buffer for complex pre-rotated samples
+} AC3MDCTContext;
+
+#endif /* AVCODEC_AC3ENC_FIXED_H */