Add MPEG-4 Audio Lossless Coding (ALS) decoder.

Patch by Thilo Borgmann, thilo D borgmann A googlemail

Originally committed as revision 20517 to svn://svn.ffmpeg.org/ffmpeg/trunk

Changelog

@@ -41,6 +41,7 @@ version <next>:
 - Atrac1 decoder
 - MD STUDIO audio demuxer
 - RF64 support in WAV demuxer
+- MPEG-4 Audio Lossless Coding (ALS) decoder
 
 
 

doc/general.texi

@@ -569,6 +569,7 @@ following image formats are supported:
 @item MP2 (MPEG audio layer 2)  @tab IX  @tab IX
 @item MP3 (MPEG audio layer 3)  @tab  E  @tab IX
     @tab encoding supported through external library LAME, ADU MP3 and MP3onMP4 also supported
+@item MPEG-4 Audio Lossless Coding (ALS)  @tab     @tab  X
 @item Musepack SV7           @tab     @tab  X
 @item Musepack SV8           @tab     @tab  X
 @item Nellymoser Asao        @tab  X  @tab  X

libavcodec/Makefile

@@ -51,6 +51,7 @@ OBJS-$(CONFIG_AC3_DECODER)             += ac3dec.o ac3tab.o   \
 OBJS-$(CONFIG_AC3_ENCODER)             += ac3enc.o ac3tab.o ac3.o
 OBJS-$(CONFIG_ALAC_DECODER)            += alac.o
 OBJS-$(CONFIG_ALAC_ENCODER)            += alacenc.o
+OBJS-$(CONFIG_ALS_DECODER)             += alsdec.o
 OBJS-$(CONFIG_AMV_DECODER)             += sp5xdec.o mjpegdec.o mjpeg.o
 OBJS-$(CONFIG_APE_DECODER)             += apedec.o
 OBJS-$(CONFIG_ASV1_DECODER)            += asv1.o mpeg12data.o

libavcodec/allcodecs.c

@@ -200,6 +200,7 @@ void avcodec_register_all(void)
     REGISTER_ENCDEC  (AAC, aac);
     REGISTER_ENCDEC  (AC3, ac3);
     REGISTER_ENCDEC  (ALAC, alac);
+    REGISTER_DECODER (ALS, als);
     REGISTER_DECODER (APE, ape);
     REGISTER_DECODER (ATRAC1, atrac1);
     REGISTER_DECODER (ATRAC3, atrac3);

libavcodec/als_data.h

+/*
+ * ALS header file for common data
+ * Copyright (c) 2009 Thilo Borgmann <thilo.borgmann _at_ googlemail.com>
+ *
+ * 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
+ */
+
+#ifndef AVCODEC_ALS_DATA_H
+#define AVCODEC_ALS_DATA_H
+
+/**
+ * @file libavcodec/als_data.h
+ * MPEG-4 ALS common data tables
+ * @author Thilo Borgmann <thilo.borgmann _at_ googlemail.com>
+ */
+
+
+#include <stdint.h>
+
+/** Rice parameters and corresponding index offsets for decoding the
+ *  indices of scaled PARCOR values. The table choosen is set globally
+ *  by the encoder and stored in ALSSpecificConfig.
+ */
+static const int8_t parcor_rice_table[3][20][2] = {
+    { {-52, 4}, {-29, 5}, {-31, 4}, { 19, 4}, {-16, 4},
+      { 12, 3}, { -7, 3}, {  9, 3}, { -5, 3}, {  6, 3},
+      { -4, 3}, {  3, 3}, { -3, 2}, {  3, 2}, { -2, 2},
+      {  3, 2}, { -1, 2}, {  2, 2}, { -1, 2}, {  2, 2} },
+    { {-58, 3}, {-42, 4}, {-46, 4}, { 37, 5}, {-36, 4},
+      { 29, 4}, {-29, 4}, { 25, 4}, {-23, 4}, { 20, 4},
+      {-17, 4}, { 16, 4}, {-12, 4}, { 12, 3}, {-10, 4},
+      {  7, 3}, { -4, 4}, {  3, 3}, { -1, 3}, {  1, 3} },
+    { {-59, 3}, {-45, 5}, {-50, 4}, { 38, 4}, {-39, 4},
+      { 32, 4}, {-30, 4}, { 25, 3}, {-23, 3}, { 20, 3},
+      {-20, 3}, { 16, 3}, {-13, 3}, { 10, 3}, { -7, 3},
+      {  3, 3}, {  0, 3}, { -1, 3}, {  2, 3}, { -1, 2} }
+};
+
+
+/** Scaled PARCOR values used for the first two PARCOR coefficients.
+ *  To be indexed by the Rice coded indices.
+ *  Generated by: parcor_scaled_values[i] = 32 + ((i * (i+1)) << 7) - (1 << 20)
+ *  Actual values are divided by 32 in order to be stored in 16 bits.
+ */
+static const int16_t parcor_scaled_values[] = {
+    -1048544 / 32, -1048288 / 32, -1047776 / 32, -1047008 / 32,
+    -1045984 / 32, -1044704 / 32, -1043168 / 32, -1041376 / 32,
+    -1039328 / 32, -1037024 / 32, -1034464 / 32, -1031648 / 32,
+    -1028576 / 32, -1025248 / 32, -1021664 / 32, -1017824 / 32,
+    -1013728 / 32, -1009376 / 32, -1004768 / 32,  -999904 / 32,
+     -994784 / 32,  -989408 / 32,  -983776 / 32,  -977888 / 32,
+     -971744 / 32,  -965344 / 32,  -958688 / 32,  -951776 / 32,
+     -944608 / 32,  -937184 / 32,  -929504 / 32,  -921568 / 32,
+     -913376 / 32,  -904928 / 32,  -896224 / 32,  -887264 / 32,
+     -878048 / 32,  -868576 / 32,  -858848 / 32,  -848864 / 32,
+     -838624 / 32,  -828128 / 32,  -817376 / 32,  -806368 / 32,
+     -795104 / 32,  -783584 / 32,  -771808 / 32,  -759776 / 32,
+     -747488 / 32,  -734944 / 32,  -722144 / 32,  -709088 / 32,
+     -695776 / 32,  -682208 / 32,  -668384 / 32,  -654304 / 32,
+     -639968 / 32,  -625376 / 32,  -610528 / 32,  -595424 / 32,
+     -580064 / 32,  -564448 / 32,  -548576 / 32,  -532448 / 32,
+     -516064 / 32,  -499424 / 32,  -482528 / 32,  -465376 / 32,
+     -447968 / 32,  -430304 / 32,  -412384 / 32,  -394208 / 32,
+     -375776 / 32,  -357088 / 32,  -338144 / 32,  -318944 / 32,
+     -299488 / 32,  -279776 / 32,  -259808 / 32,  -239584 / 32,
+     -219104 / 32,  -198368 / 32,  -177376 / 32,  -156128 / 32,
+     -134624 / 32,  -112864 / 32,   -90848 / 32,   -68576 / 32,
+      -46048 / 32,   -23264 / 32,     -224 / 32,    23072 / 32,
+       46624 / 32,    70432 / 32,    94496 / 32,   118816 / 32,
+      143392 / 32,   168224 / 32,   193312 / 32,   218656 / 32,
+      244256 / 32,   270112 / 32,   296224 / 32,   322592 / 32,
+      349216 / 32,   376096 / 32,   403232 / 32,   430624 / 32,
+      458272 / 32,   486176 / 32,   514336 / 32,   542752 / 32,
+      571424 / 32,   600352 / 32,   629536 / 32,   658976 / 32,
+      688672 / 32,   718624 / 32,   748832 / 32,   779296 / 32,
+      810016 / 32,   840992 / 32,   872224 / 32,   903712 / 32,
+      935456 / 32,   967456 / 32,   999712 / 32,  1032224 / 32
+};
+
+
+#endif /* AVCODEC_ALS_DATA_H */