Initial commit of the atrac1 decoder, not hooked up yet

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@19811 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

libavcodec/atrac1data.h

+/*
+ * Atrac 1 compatible decoder data
+ * Copyright (c) 2009 Maxim Poliakovski
+ * Copyright (c) 2009 Benjamin Larsson
+ *
+ * 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 libavcodec/atrac1data.h
+ * Atrac 1 compatible decoder data
+ */
+
+#ifndef AVCODEC_ATRAC1DATA_H
+#define AVCODEC_ATRAC1DATA_H
+
+static const uint8_t bfu_amount_tab1[8] = {20,  28,  32,  36, 40, 44, 48, 52};
+static const uint8_t bfu_amount_tab2[4] = { 0, 112, 176, 208};
+static const uint8_t bfu_amount_tab3[8] = { 0,  24,  36,  48, 72, 108, 132, 156};
+
+/** number of BFUs in each QMF band */
+static const uint8_t bfu_bands_t[4]  = {0, 20, 36, 52};
+
+/** number of spectral lines in each BFU
+ *  block floating unit = group of spectral frequencies having the
+ *  same quantization parameters like word length and scale factor
+ */
+static const uint8_t specs_per_bfu[52] = {
+     8,  8,  8,  8,  4,  4,  4,  4,  8,  8,  8,  8,  6,  6,  6,  6, 6, 6, 6, 6, // low band
+     6,  6,  6,  6,  7,  7,  7,  7,  9,  9,  9,  9, 10, 10, 10, 10,             // midle band
+    12, 12, 12, 12, 12, 12, 12, 12, 20, 20, 20, 20, 20, 20, 20, 20              // high band
+};
+
+/** start position of each BFU in the MDCT spectrum for the long mode */
+static const uint16_t bfu_start_long[52] = {
+      0,   8,  16,  24,  32,  36,  40,  44,  48,  56,  64,  72,  80,  86,  92,  98, 104, 110, 116, 122,
+    128, 134, 140, 146, 152, 159, 166, 173, 180, 189, 198, 207, 216, 226, 236, 246,
+    256, 268, 280, 292, 304, 316, 328, 340, 352, 372, 392, 412, 432, 452, 472, 492,
+};
+
+/** start position of each BFU in the MDCT spectrum for the short mode */
+static const uint16_t bfu_start_short[52] = {
+      0,  32,  64,  96,   8,  40,  72, 104,  12,  44,  76, 108,  20,  52,  84, 116, 26, 58, 90, 122,
+    128, 160, 192, 224, 134, 166, 198, 230, 141, 173, 205, 237, 150, 182, 214, 246,
+    256, 288, 320, 352, 384, 416, 448, 480, 268, 300, 332, 364, 396, 428, 460, 492
+};
+
+#endif /* AVCODEC_ATRAC1DATA_H */