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/*
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 * MPEG-4 ALS decoder
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 * Copyright (c) 2009 Thilo Borgmann <thilo.borgmann _at_ googlemail.com>
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 *
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 * This file is part of FFmpeg.
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 *
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 * FFmpeg is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * FFmpeg is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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/**
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 * @file libavcodec/alsdec.c
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 * MPEG-4 ALS decoder
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 * @author Thilo Borgmann <thilo.borgmann _at_ googlemail.com>
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 */
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28

    
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//#define DEBUG
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#include "avcodec.h"
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#include "get_bits.h"
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#include "unary.h"
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#include "mpeg4audio.h"
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#include "bytestream.h"
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#include "bgmc.h"
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39
#include <stdint.h>
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/** Rice parameters and corresponding index offsets for decoding the
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 *  indices of scaled PARCOR values. The table choosen is set globally
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 *  by the encoder and stored in ALSSpecificConfig.
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 */
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static const int8_t parcor_rice_table[3][20][2] = {
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    { {-52, 4}, {-29, 5}, {-31, 4}, { 19, 4}, {-16, 4},
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      { 12, 3}, { -7, 3}, {  9, 3}, { -5, 3}, {  6, 3},
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      { -4, 3}, {  3, 3}, { -3, 2}, {  3, 2}, { -2, 2},
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      {  3, 2}, { -1, 2}, {  2, 2}, { -1, 2}, {  2, 2} },
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    { {-58, 3}, {-42, 4}, {-46, 4}, { 37, 5}, {-36, 4},
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      { 29, 4}, {-29, 4}, { 25, 4}, {-23, 4}, { 20, 4},
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      {-17, 4}, { 16, 4}, {-12, 4}, { 12, 3}, {-10, 4},
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      {  7, 3}, { -4, 4}, {  3, 3}, { -1, 3}, {  1, 3} },
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    { {-59, 3}, {-45, 5}, {-50, 4}, { 38, 4}, {-39, 4},
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      { 32, 4}, {-30, 4}, { 25, 3}, {-23, 3}, { 20, 3},
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      {-20, 3}, { 16, 3}, {-13, 3}, { 10, 3}, { -7, 3},
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      {  3, 3}, {  0, 3}, { -1, 3}, {  2, 3}, { -1, 2} }
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};
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/** Scaled PARCOR values used for the first two PARCOR coefficients.
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 *  To be indexed by the Rice coded indices.
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 *  Generated by: parcor_scaled_values[i] = 32 + ((i * (i+1)) << 7) - (1 << 20)
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 *  Actual values are divided by 32 in order to be stored in 16 bits.
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 */
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static const int16_t parcor_scaled_values[] = {
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    -1048544 / 32, -1048288 / 32, -1047776 / 32, -1047008 / 32,
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    -1045984 / 32, -1044704 / 32, -1043168 / 32, -1041376 / 32,
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    -1039328 / 32, -1037024 / 32, -1034464 / 32, -1031648 / 32,
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    -1028576 / 32, -1025248 / 32, -1021664 / 32, -1017824 / 32,
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    -1013728 / 32, -1009376 / 32, -1004768 / 32,  -999904 / 32,
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     -994784 / 32,  -989408 / 32,  -983776 / 32,  -977888 / 32,
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     -971744 / 32,  -965344 / 32,  -958688 / 32,  -951776 / 32,
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     -944608 / 32,  -937184 / 32,  -929504 / 32,  -921568 / 32,
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     -913376 / 32,  -904928 / 32,  -896224 / 32,  -887264 / 32,
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     -878048 / 32,  -868576 / 32,  -858848 / 32,  -848864 / 32,
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     -838624 / 32,  -828128 / 32,  -817376 / 32,  -806368 / 32,
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     -795104 / 32,  -783584 / 32,  -771808 / 32,  -759776 / 32,
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     -747488 / 32,  -734944 / 32,  -722144 / 32,  -709088 / 32,
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     -695776 / 32,  -682208 / 32,  -668384 / 32,  -654304 / 32,
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     -639968 / 32,  -625376 / 32,  -610528 / 32,  -595424 / 32,
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     -580064 / 32,  -564448 / 32,  -548576 / 32,  -532448 / 32,
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     -516064 / 32,  -499424 / 32,  -482528 / 32,  -465376 / 32,
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     -447968 / 32,  -430304 / 32,  -412384 / 32,  -394208 / 32,
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     -375776 / 32,  -357088 / 32,  -338144 / 32,  -318944 / 32,
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     -299488 / 32,  -279776 / 32,  -259808 / 32,  -239584 / 32,
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     -219104 / 32,  -198368 / 32,  -177376 / 32,  -156128 / 32,
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     -134624 / 32,  -112864 / 32,   -90848 / 32,   -68576 / 32,
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      -46048 / 32,   -23264 / 32,     -224 / 32,    23072 / 32,
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       46624 / 32,    70432 / 32,    94496 / 32,   118816 / 32,
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      143392 / 32,   168224 / 32,   193312 / 32,   218656 / 32,
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      244256 / 32,   270112 / 32,   296224 / 32,   322592 / 32,
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      349216 / 32,   376096 / 32,   403232 / 32,   430624 / 32,
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      458272 / 32,   486176 / 32,   514336 / 32,   542752 / 32,
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      571424 / 32,   600352 / 32,   629536 / 32,   658976 / 32,
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      688672 / 32,   718624 / 32,   748832 / 32,   779296 / 32,
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      810016 / 32,   840992 / 32,   872224 / 32,   903712 / 32,
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      935456 / 32,   967456 / 32,   999712 / 32,  1032224 / 32
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};
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/** Gain values of p(0) for long-term prediction.
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 *  To be indexed by the Rice coded indices.
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 */
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static const uint8_t ltp_gain_values [4][4] = {
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    { 0,  8, 16,  24},
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    {32, 40, 48,  56},
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    {64, 70, 76,  82},
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    {88, 92, 96, 100}
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};
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/** Inter-channel weighting factors for multi-channel correlation.
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 *  To be indexed by the Rice coded indices.
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 */
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static const int16_t mcc_weightings[] = {
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    204,  192,  179,  166,  153,  140,  128,  115,
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    102,   89,   76,   64,   51,   38,   25,   12,
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      0,  -12,  -25,  -38,  -51,  -64,  -76,  -89,
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   -102, -115, -128, -140, -153, -166, -179, -192
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};
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/** Tail codes used in arithmetic coding using block Gilbert-Moore codes.
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 */
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static const uint8_t tail_code[16][6] = {
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    { 74, 44, 25, 13,  7, 3},
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    { 68, 42, 24, 13,  7, 3},
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    { 58, 39, 23, 13,  7, 3},
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    {126, 70, 37, 19, 10, 5},
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    {132, 70, 37, 20, 10, 5},
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    {124, 70, 38, 20, 10, 5},
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    {120, 69, 37, 20, 11, 5},
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    {116, 67, 37, 20, 11, 5},
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    {108, 66, 36, 20, 10, 5},
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    {102, 62, 36, 20, 10, 5},
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    { 88, 58, 34, 19, 10, 5},
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    {162, 89, 49, 25, 13, 7},
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    {156, 87, 49, 26, 14, 7},
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    {150, 86, 47, 26, 14, 7},
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    {142, 84, 47, 26, 14, 7},
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    {131, 79, 46, 26, 14, 7}
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};
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146
enum RA_Flag {
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    RA_FLAG_NONE,
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    RA_FLAG_FRAMES,
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    RA_FLAG_HEADER
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};
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typedef struct {
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    uint32_t samples;         ///< number of samples, 0xFFFFFFFF if unknown
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    int resolution;           ///< 000 = 8-bit; 001 = 16-bit; 010 = 24-bit; 011 = 32-bit
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    int floating;             ///< 1 = IEEE 32-bit floating-point, 0 = integer
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    int frame_length;         ///< frame length for each frame (last frame may differ)
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    int ra_distance;          ///< distance between RA frames (in frames, 0...255)
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    enum RA_Flag ra_flag;     ///< indicates where the size of ra units is stored
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    int adapt_order;          ///< adaptive order: 1 = on, 0 = off
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    int coef_table;           ///< table index of Rice code parameters
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    int long_term_prediction; ///< long term prediction (LTP): 1 = on, 0 = off
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    int max_order;            ///< maximum prediction order (0..1023)
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    int block_switching;      ///< number of block switching levels
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    int bgmc;                 ///< "Block Gilbert-Moore Code": 1 = on, 0 = off (Rice coding only)
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    int sb_part;              ///< sub-block partition
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    int joint_stereo;         ///< joint stereo: 1 = on, 0 = off
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    int mc_coding;            ///< extended inter-channel coding (multi channel coding): 1 = on, 0 = off
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    int chan_config;          ///< indicates that a chan_config_info field is present
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    int chan_sort;            ///< channel rearrangement: 1 = on, 0 = off
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    int rlslms;               ///< use "Recursive Least Square-Least Mean Square" predictor: 1 = on, 0 = off
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    int chan_config_info;     ///< mapping of channels to loudspeaker locations. Unused until setting channel configuration is implemented.
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    int *chan_pos;            ///< original channel positions
174
} ALSSpecificConfig;
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typedef struct {
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    int stop_flag;
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    int master_channel;
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    int time_diff_flag;
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    int time_diff_sign;
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    int time_diff_index;
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    int weighting[6];
184
} ALSChannelData;
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186

    
187
typedef struct {
188
    AVCodecContext *avctx;
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    ALSSpecificConfig sconf;
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    GetBitContext gb;
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    unsigned int cur_frame_length;  ///< length of the current frame to decode
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    unsigned int frame_id;          ///< the frame ID / number of the current frame
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    unsigned int js_switch;         ///< if true, joint-stereo decoding is enforced
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    unsigned int num_blocks;        ///< number of blocks used in the current frame
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    unsigned int s_max;             ///< maximum Rice parameter allowed in entropy coding
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    uint8_t *bgmc_lut;              ///< pointer at lookup tables used for BGMC
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    unsigned int *bgmc_lut_status;  ///< pointer at lookup table status flags used for BGMC
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    int ltp_lag_length;             ///< number of bits used for ltp lag value
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    int *use_ltp;                   ///< contains use_ltp flags for all channels
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    int *ltp_lag;                   ///< contains ltp lag values for all channels
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    int **ltp_gain;                 ///< gain values for ltp 5-tap filter for a channel
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    int *ltp_gain_buffer;           ///< contains all gain values for ltp 5-tap filter
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    int32_t **quant_cof;            ///< quantized parcor coefficients for a channel
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    int32_t *quant_cof_buffer;      ///< contains all quantized parcor coefficients
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    int32_t **lpc_cof;              ///< coefficients of the direct form prediction filter for a channel
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    int32_t *lpc_cof_buffer;        ///< contains all coefficients of the direct form prediction filter
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    int32_t *lpc_cof_reversed_buffer; ///< temporary buffer to set up a reversed versio of lpc_cof_buffer
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    ALSChannelData **chan_data;     ///< channel data for multi-channel correlation
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    ALSChannelData *chan_data_buffer; ///< contains channel data for all channels
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    int *reverted_channels;         ///< stores a flag for each reverted channel
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    int32_t *prev_raw_samples;      ///< contains unshifted raw samples from the previous block
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    int32_t **raw_samples;          ///< decoded raw samples for each channel
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    int32_t *raw_buffer;            ///< contains all decoded raw samples including carryover samples
214
} ALSDecContext;
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typedef struct {
218
    unsigned int block_length;      ///< number of samples within the block
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    unsigned int ra_block;          ///< if true, this is a random access block
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    int          const_block;       ///< if true, this is a constant value block
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    int32_t      const_val;         ///< the sample value of a constant block
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    int          js_blocks;         ///< true if this block contains a difference signal
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    unsigned int shift_lsbs;        ///< shift of values for this block
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    unsigned int opt_order;         ///< prediction order of this block
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    int          store_prev_samples;///< if true, carryover samples have to be stored
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    int          *use_ltp;          ///< if true, long-term prediction is used
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    int          *ltp_lag;          ///< lag value for long-term prediction
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    int          *ltp_gain;         ///< gain values for ltp 5-tap filter
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    int32_t      *quant_cof;        ///< quantized parcor coefficients
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    int32_t      *lpc_cof;          ///< coefficients of the direct form prediction
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    int32_t      *raw_samples;      ///< decoded raw samples / residuals for this block
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    int32_t      *prev_raw_samples; ///< contains unshifted raw samples from the previous block
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    int32_t      *raw_other;        ///< decoded raw samples of the other channel of a channel pair
234
} ALSBlockData;
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237
static av_cold void dprint_specific_config(ALSDecContext *ctx)
238
{
239
#ifdef DEBUG
240
    AVCodecContext *avctx    = ctx->avctx;
241
    ALSSpecificConfig *sconf = &ctx->sconf;
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    dprintf(avctx, "resolution = %i\n",           sconf->resolution);
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    dprintf(avctx, "floating = %i\n",             sconf->floating);
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    dprintf(avctx, "frame_length = %i\n",         sconf->frame_length);
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    dprintf(avctx, "ra_distance = %i\n",          sconf->ra_distance);
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    dprintf(avctx, "ra_flag = %i\n",              sconf->ra_flag);
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    dprintf(avctx, "adapt_order = %i\n",          sconf->adapt_order);
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    dprintf(avctx, "coef_table = %i\n",           sconf->coef_table);
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    dprintf(avctx, "long_term_prediction = %i\n", sconf->long_term_prediction);
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    dprintf(avctx, "max_order = %i\n",            sconf->max_order);
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    dprintf(avctx, "block_switching = %i\n",      sconf->block_switching);
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    dprintf(avctx, "bgmc = %i\n",                 sconf->bgmc);
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    dprintf(avctx, "sb_part = %i\n",              sconf->sb_part);
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    dprintf(avctx, "joint_stereo = %i\n",         sconf->joint_stereo);
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    dprintf(avctx, "mc_coding = %i\n",            sconf->mc_coding);
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    dprintf(avctx, "chan_config = %i\n",          sconf->chan_config);
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    dprintf(avctx, "chan_sort = %i\n",            sconf->chan_sort);
259
    dprintf(avctx, "RLSLMS = %i\n",               sconf->rlslms);
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    dprintf(avctx, "chan_config_info = %i\n",     sconf->chan_config_info);
261
#endif
262
}
263

    
264

    
265
/** Reads an ALSSpecificConfig from a buffer into the output struct.
266
 */
267
static av_cold int read_specific_config(ALSDecContext *ctx)
268
{
269
    GetBitContext gb;
270
    uint64_t ht_size;
271
    int i, config_offset, crc_enabled;
272
    MPEG4AudioConfig m4ac;
273
    ALSSpecificConfig *sconf = &ctx->sconf;
274
    AVCodecContext *avctx    = ctx->avctx;
275
    uint32_t als_id, header_size, trailer_size;
276

    
277
    init_get_bits(&gb, avctx->extradata, avctx->extradata_size * 8);
278

    
279
    config_offset = ff_mpeg4audio_get_config(&m4ac, avctx->extradata,
280
                                             avctx->extradata_size);
281

    
282
    if (config_offset < 0)
283
        return -1;
284

    
285
    skip_bits_long(&gb, config_offset);
286

    
287
    if (get_bits_left(&gb) < (30 << 3))
288
        return -1;
289

    
290
    // read the fixed items
291
    als_id                      = get_bits_long(&gb, 32);
292
    avctx->sample_rate          = m4ac.sample_rate;
293
    skip_bits_long(&gb, 32); // sample rate already known
294
    sconf->samples              = get_bits_long(&gb, 32);
295
    avctx->channels             = m4ac.channels;
296
    skip_bits(&gb, 16);      // number of channels already knwon
297
    skip_bits(&gb, 3);       // skip file_type
298
    sconf->resolution           = get_bits(&gb, 3);
299
    sconf->floating             = get_bits1(&gb);
300
    skip_bits1(&gb);         // skip msb_first
301
    sconf->frame_length         = get_bits(&gb, 16) + 1;
302
    sconf->ra_distance          = get_bits(&gb, 8);
303
    sconf->ra_flag              = get_bits(&gb, 2);
304
    sconf->adapt_order          = get_bits1(&gb);
305
    sconf->coef_table           = get_bits(&gb, 2);
306
    sconf->long_term_prediction = get_bits1(&gb);
307
    sconf->max_order            = get_bits(&gb, 10);
308
    sconf->block_switching      = get_bits(&gb, 2);
309
    sconf->bgmc                 = get_bits1(&gb);
310
    sconf->sb_part              = get_bits1(&gb);
311
    sconf->joint_stereo         = get_bits1(&gb);
312
    sconf->mc_coding            = get_bits1(&gb);
313
    sconf->chan_config          = get_bits1(&gb);
314
    sconf->chan_sort            = get_bits1(&gb);
315
    crc_enabled                 = get_bits1(&gb);
316
    sconf->rlslms               = get_bits1(&gb);
317
    skip_bits(&gb, 5);       // skip 5 reserved bits
318
    skip_bits1(&gb);         // skip aux_data_enabled
319

    
320

    
321
    // check for ALSSpecificConfig struct
322
    if (als_id != MKBETAG('A','L','S','\0'))
323
        return -1;
324

    
325
    ctx->cur_frame_length = sconf->frame_length;
326

    
327
    // read channel config
328
    if (sconf->chan_config)
329
        sconf->chan_config_info = get_bits(&gb, 16);
330
    // TODO: use this to set avctx->channel_layout
331

    
332

    
333
    // read channel sorting
334
    if (sconf->chan_sort && avctx->channels > 1) {
335
        int chan_pos_bits = av_ceil_log2(avctx->channels);
336
        int bits_needed  = avctx->channels * chan_pos_bits + 7;
337
        if (get_bits_left(&gb) < bits_needed)
338
            return -1;
339

    
340
        if (!(sconf->chan_pos = av_malloc(avctx->channels * sizeof(*sconf->chan_pos))))
341
            return AVERROR(ENOMEM);
342

    
343
        for (i = 0; i < avctx->channels; i++)
344
            sconf->chan_pos[i] = get_bits(&gb, chan_pos_bits);
345

    
346
        align_get_bits(&gb);
347
        // TODO: use this to actually do channel sorting
348
    } else {
349
        sconf->chan_sort = 0;
350
    }
351

    
352

    
353
    // read fixed header and trailer sizes,
354
    // if size = 0xFFFFFFFF then there is no data field!
355
    if (get_bits_left(&gb) < 64)
356
        return -1;
357

    
358
    header_size  = get_bits_long(&gb, 32);
359
    trailer_size = get_bits_long(&gb, 32);
360
    if (header_size  == 0xFFFFFFFF)
361
        header_size  = 0;
362
    if (trailer_size == 0xFFFFFFFF)
363
        trailer_size = 0;
364

    
365
    ht_size = ((int64_t)(header_size) + (int64_t)(trailer_size)) << 3;
366

    
367

    
368
    // skip the header and trailer data
369
    if (get_bits_left(&gb) < ht_size)
370
        return -1;
371

    
372
    if (ht_size > INT32_MAX)
373
        return -1;
374

    
375
    skip_bits_long(&gb, ht_size);
376

    
377

    
378
    // skip the crc data
379
    if (crc_enabled) {
380
        if (get_bits_left(&gb) < 32)
381
            return -1;
382

    
383
        skip_bits_long(&gb, 32);
384
    }
385

    
386

    
387
    // no need to read the rest of ALSSpecificConfig (ra_unit_size & aux data)
388

    
389
    dprint_specific_config(ctx);
390

    
391
    return 0;
392
}
393

    
394

    
395
/** Checks the ALSSpecificConfig for unsupported features.
396
 */
397
static int check_specific_config(ALSDecContext *ctx)
398
{
399
    ALSSpecificConfig *sconf = &ctx->sconf;
400
    int error = 0;
401

    
402
    // report unsupported feature and set error value
403
    #define MISSING_ERR(cond, str, errval)              \
404
    {                                                   \
405
        if (cond) {                                     \
406
            av_log_missing_feature(ctx->avctx, str, 0); \
407
            error = errval;                             \
408
        }                                               \
409
    }
410

    
411
    MISSING_ERR(sconf->floating,             "Floating point decoding",     -1);
412
    MISSING_ERR(sconf->rlslms,               "Adaptive RLS-LMS prediction", -1);
413
    MISSING_ERR(sconf->chan_sort,            "Channel sorting",              0);
414

    
415
    return error;
416
}
417

    
418

    
419
/** Parses the bs_info field to extract the block partitioning used in
420
 *  block switching mode, refer to ISO/IEC 14496-3, section 11.6.2.
421
 */
422
static void parse_bs_info(const uint32_t bs_info, unsigned int n,
423
                          unsigned int div, unsigned int **div_blocks,
424
                          unsigned int *num_blocks)
425
{
426
    if (n < 31 && ((bs_info << n) & 0x40000000)) {
427
        // if the level is valid and the investigated bit n is set
428
        // then recursively check both children at bits (2n+1) and (2n+2)
429
        n   *= 2;
430
        div += 1;
431
        parse_bs_info(bs_info, n + 1, div, div_blocks, num_blocks);
432
        parse_bs_info(bs_info, n + 2, div, div_blocks, num_blocks);
433
    } else {
434
        // else the bit is not set or the last level has been reached
435
        // (bit implicitly not set)
436
        **div_blocks = div;
437
        (*div_blocks)++;
438
        (*num_blocks)++;
439
    }
440
}
441

    
442

    
443
/** Reads and decodes a Rice codeword.
444
 */
445
static int32_t decode_rice(GetBitContext *gb, unsigned int k)
446
{
447
    int max = get_bits_left(gb) - k;
448
    int q   = get_unary(gb, 0, max);
449
    int r   = k ? get_bits1(gb) : !(q & 1);
450

    
451
    if (k > 1) {
452
        q <<= (k - 1);
453
        q  += get_bits_long(gb, k - 1);
454
    } else if (!k) {
455
        q >>= 1;
456
    }
457
    return r ? q : ~q;
458
}
459

    
460

    
461
/** Converts PARCOR coefficient k to direct filter coefficient.
462
 */
463
static void parcor_to_lpc(unsigned int k, const int32_t *par, int32_t *cof)
464
{
465
    int i, j;
466

    
467
    for (i = 0, j = k - 1; i < j; i++, j--) {
468
        int tmp1 = ((MUL64(par[k], cof[j]) + (1 << 19)) >> 20);
469
        cof[j]  += ((MUL64(par[k], cof[i]) + (1 << 19)) >> 20);
470
        cof[i]  += tmp1;
471
    }
472
    if (i == j)
473
        cof[i] += ((MUL64(par[k], cof[j]) + (1 << 19)) >> 20);
474

    
475
    cof[k] = par[k];
476
}
477

    
478

    
479
/** Reads block switching field if necessary and sets actual block sizes.
480
 *  Also assures that the block sizes of the last frame correspond to the
481
 *  actual number of samples.
482
 */
483
static void get_block_sizes(ALSDecContext *ctx, unsigned int *div_blocks,
484
                            uint32_t *bs_info)
485
{
486
    ALSSpecificConfig *sconf     = &ctx->sconf;
487
    GetBitContext *gb            = &ctx->gb;
488
    unsigned int *ptr_div_blocks = div_blocks;
489
    unsigned int b;
490

    
491
    if (sconf->block_switching) {
492
        unsigned int bs_info_len = 1 << (sconf->block_switching + 2);
493
        *bs_info = get_bits_long(gb, bs_info_len);
494
        *bs_info <<= (32 - bs_info_len);
495
    }
496

    
497
    ctx->num_blocks = 0;
498
    parse_bs_info(*bs_info, 0, 0, &ptr_div_blocks, &ctx->num_blocks);
499

    
500
    // The last frame may have an overdetermined block structure given in
501
    // the bitstream. In that case the defined block structure would need
502
    // more samples than available to be consistent.
503
    // The block structure is actually used but the block sizes are adapted
504
    // to fit the actual number of available samples.
505
    // Example: 5 samples, 2nd level block sizes: 2 2 2 2.
506
    // This results in the actual block sizes:    2 2 1 0.
507
    // This is not specified in 14496-3 but actually done by the reference
508
    // codec RM22 revision 2.
509
    // This appears to happen in case of an odd number of samples in the last
510
    // frame which is actually not allowed by the block length switching part
511
    // of 14496-3.
512
    // The ALS conformance files feature an odd number of samples in the last
513
    // frame.
514

    
515
    for (b = 0; b < ctx->num_blocks; b++)
516
        div_blocks[b] = ctx->sconf.frame_length >> div_blocks[b];
517

    
518
    if (ctx->cur_frame_length != ctx->sconf.frame_length) {
519
        unsigned int remaining = ctx->cur_frame_length;
520

    
521
        for (b = 0; b < ctx->num_blocks; b++) {
522
            if (remaining <= div_blocks[b]) {
523
                div_blocks[b] = remaining;
524
                ctx->num_blocks = b + 1;
525
                break;
526
            }
527

    
528
            remaining -= div_blocks[b];
529
        }
530
    }
531
}
532

    
533

    
534
/** Reads the block data for a constant block
535
 */
536
static void read_const_block_data(ALSDecContext *ctx, ALSBlockData *bd)
537
{
538
    ALSSpecificConfig *sconf = &ctx->sconf;
539
    AVCodecContext *avctx    = ctx->avctx;
540
    GetBitContext *gb        = &ctx->gb;
541

    
542
    bd->const_val    = 0;
543
    bd->const_block  = get_bits1(gb);    // 1 = constant value, 0 = zero block (silence)
544
    bd->js_blocks    = get_bits1(gb);
545

    
546
    // skip 5 reserved bits
547
    skip_bits(gb, 5);
548

    
549
    if (bd->const_block) {
550
        unsigned int const_val_bits = sconf->floating ? 24 : avctx->bits_per_raw_sample;
551
        bd->const_val = get_sbits_long(gb, const_val_bits);
552
    }
553

    
554
    // ensure constant block decoding by reusing this field
555
    bd->const_block = 1;
556
}
557

    
558

    
559
/** Decodes the block data for a constant block
560
 */
561
static void decode_const_block_data(ALSDecContext *ctx, ALSBlockData *bd)
562
{
563
    int      smp = bd->block_length;
564
    int32_t  val = bd->const_val;
565
    int32_t *dst = bd->raw_samples;
566

    
567
    // write raw samples into buffer
568
    for (; smp; smp--)
569
        *dst++ = val;
570
}
571

    
572

    
573
/** Reads the block data for a non-constant block
574
 */
575
static int read_var_block_data(ALSDecContext *ctx, ALSBlockData *bd)
576
{
577
    ALSSpecificConfig *sconf = &ctx->sconf;
578
    AVCodecContext *avctx    = ctx->avctx;
579
    GetBitContext *gb        = &ctx->gb;
580
    unsigned int k;
581
    unsigned int s[8];
582
    unsigned int sx[8];
583
    unsigned int sub_blocks, log2_sub_blocks, sb_length;
584
    unsigned int start      = 0;
585
    unsigned int opt_order;
586
    int          sb;
587
    int32_t      *quant_cof = bd->quant_cof;
588
    int32_t      *current_res;
589

    
590

    
591
    // ensure variable block decoding by reusing this field
592
    bd->const_block = 0;
593

    
594
    bd->opt_order   = 1;
595
    bd->js_blocks   = get_bits1(gb);
596

    
597
    opt_order       = bd->opt_order;
598

    
599
    // determine the number of subblocks for entropy decoding
600
    if (!sconf->bgmc && !sconf->sb_part) {
601
        log2_sub_blocks = 0;
602
    } else {
603
        if (sconf->bgmc && sconf->sb_part)
604
            log2_sub_blocks = get_bits(gb, 2);
605
        else
606
            log2_sub_blocks = 2 * get_bits1(gb);
607
    }
608

    
609
    sub_blocks = 1 << log2_sub_blocks;
610

    
611
    // do not continue in case of a damaged stream since
612
    // block_length must be evenly divisible by sub_blocks
613
    if (bd->block_length & (sub_blocks - 1)) {
614
        av_log(avctx, AV_LOG_WARNING,
615
               "Block length is not evenly divisible by the number of subblocks.\n");
616
        return -1;
617
    }
618

    
619
    sb_length = bd->block_length >> log2_sub_blocks;
620

    
621
    if (sconf->bgmc) {
622
        s[0] = get_bits(gb, 8 + (sconf->resolution > 1));
623
        for (k = 1; k < sub_blocks; k++)
624
            s[k] = s[k - 1] + decode_rice(gb, 2);
625

    
626
        for (k = 0; k < sub_blocks; k++) {
627
            sx[k]   = s[k] & 0x0F;
628
            s [k] >>= 4;
629
        }
630
    } else {
631
        s[0] = get_bits(gb, 4 + (sconf->resolution > 1));
632
        for (k = 1; k < sub_blocks; k++)
633
            s[k] = s[k - 1] + decode_rice(gb, 0);
634
    }
635

    
636
    if (get_bits1(gb))
637
        bd->shift_lsbs = get_bits(gb, 4) + 1;
638

    
639
    bd->store_prev_samples = (bd->js_blocks && bd->raw_other) || bd->shift_lsbs;
640

    
641

    
642
    if (!sconf->rlslms) {
643
        if (sconf->adapt_order) {
644
            int opt_order_length = av_ceil_log2(av_clip((bd->block_length >> 3) - 1,
645
                                                2, sconf->max_order + 1));
646
            bd->opt_order        = get_bits(gb, opt_order_length);
647
        } else {
648
            bd->opt_order = sconf->max_order;
649
        }
650

    
651
        opt_order = bd->opt_order;
652

    
653
        if (opt_order) {
654
            int add_base;
655

    
656
            if (sconf->coef_table == 3) {
657
                add_base = 0x7F;
658

    
659
                // read coefficient 0
660
                quant_cof[0] = 32 * parcor_scaled_values[get_bits(gb, 7)];
661

    
662
                // read coefficient 1
663
                if (opt_order > 1)
664
                    quant_cof[1] = -32 * parcor_scaled_values[get_bits(gb, 7)];
665

    
666
                // read coefficients 2 to opt_order
667
                for (k = 2; k < opt_order; k++)
668
                    quant_cof[k] = get_bits(gb, 7);
669
            } else {
670
                int k_max;
671
                add_base = 1;
672

    
673
                // read coefficient 0 to 19
674
                k_max = FFMIN(opt_order, 20);
675
                for (k = 0; k < k_max; k++) {
676
                    int rice_param = parcor_rice_table[sconf->coef_table][k][1];
677
                    int offset     = parcor_rice_table[sconf->coef_table][k][0];
678
                    quant_cof[k] = decode_rice(gb, rice_param) + offset;
679
                }
680

    
681
                // read coefficients 20 to 126
682
                k_max = FFMIN(opt_order, 127);
683
                for (; k < k_max; k++)
684
                    quant_cof[k] = decode_rice(gb, 2) + (k & 1);
685

    
686
                // read coefficients 127 to opt_order
687
                for (; k < opt_order; k++)
688
                    quant_cof[k] = decode_rice(gb, 1);
689

    
690
                quant_cof[0] = 32 * parcor_scaled_values[quant_cof[0] + 64];
691

    
692
                if (opt_order > 1)
693
                    quant_cof[1] = -32 * parcor_scaled_values[quant_cof[1] + 64];
694
            }
695

    
696
            for (k = 2; k < opt_order; k++)
697
                quant_cof[k] = (quant_cof[k] << 14) + (add_base << 13);
698
        }
699
    }
700

    
701
    // read LTP gain and lag values
702
    if (sconf->long_term_prediction) {
703
        *bd->use_ltp = get_bits1(gb);
704

    
705
        if (*bd->use_ltp) {
706
            int r, c;
707

    
708
            bd->ltp_gain[0]   = decode_rice(gb, 1) << 3;
709
            bd->ltp_gain[1]   = decode_rice(gb, 2) << 3;
710

    
711
            r                 = get_unary(gb, 0, 4);
712
            c                 = get_bits(gb, 2);
713
            bd->ltp_gain[2]   = ltp_gain_values[r][c];
714

    
715
            bd->ltp_gain[3]   = decode_rice(gb, 2) << 3;
716
            bd->ltp_gain[4]   = decode_rice(gb, 1) << 3;
717

    
718
            *bd->ltp_lag      = get_bits(gb, ctx->ltp_lag_length);
719
            *bd->ltp_lag     += FFMAX(4, opt_order + 1);
720
        }
721
    }
722

    
723
    // read first value and residuals in case of a random access block
724
    if (bd->ra_block) {
725
        if (opt_order)
726
            bd->raw_samples[0] = decode_rice(gb, avctx->bits_per_raw_sample - 4);
727
        if (opt_order > 1)
728
            bd->raw_samples[1] = decode_rice(gb, FFMIN(s[0] + 3, ctx->s_max));
729
        if (opt_order > 2)
730
            bd->raw_samples[2] = decode_rice(gb, FFMIN(s[0] + 1, ctx->s_max));
731

    
732
        start = FFMIN(opt_order, 3);
733
    }
734

    
735
    // read all residuals
736
    if (sconf->bgmc) {
737
        unsigned int delta[sub_blocks];
738
        unsigned int k    [sub_blocks];
739
        unsigned int b = av_clip((av_ceil_log2(bd->block_length) - 3) >> 1, 0, 5);
740
        unsigned int i = start;
741

    
742
        // read most significant bits
743
        unsigned int high;
744
        unsigned int low;
745
        unsigned int value;
746

    
747
        ff_bgmc_decode_init(gb, &high, &low, &value);
748

    
749
        current_res = bd->raw_samples + start;
750

    
751
        for (sb = 0; sb < sub_blocks; sb++, i = 0) {
752
            k    [sb] = s[sb] > b ? s[sb] - b : 0;
753
            delta[sb] = 5 - s[sb] + k[sb];
754

    
755
            ff_bgmc_decode(gb, sb_length, current_res,
756
                        delta[sb], sx[sb], &high, &low, &value, ctx->bgmc_lut, ctx->bgmc_lut_status);
757

    
758
            current_res += sb_length;
759
        }
760

    
761
        ff_bgmc_decode_end(gb);
762

    
763

    
764
        // read least significant bits and tails
765
        i = start;
766
        current_res = bd->raw_samples + start;
767

    
768
        for (sb = 0; sb < sub_blocks; sb++, i = 0) {
769
            unsigned int cur_tail_code = tail_code[sx[sb]][delta[sb]];
770
            unsigned int cur_k         = k[sb];
771
            unsigned int cur_s         = s[sb];
772

    
773
            for (; i < sb_length; i++) {
774
                int32_t res = *current_res;
775

    
776
                if (res == cur_tail_code) {
777
                    unsigned int max_msb =   (2 + (sx[sb] > 2) + (sx[sb] > 10))
778
                                          << (5 - delta[sb]);
779

    
780
                    res = decode_rice(gb, cur_s);
781

    
782
                    if (res >= 0) {
783
                        res += (max_msb    ) << cur_k;
784
                    } else {
785
                        res -= (max_msb - 1) << cur_k;
786
                    }
787
                } else {
788
                    if (res > cur_tail_code)
789
                        res--;
790

    
791
                    if (res & 1)
792
                        res = -res;
793

    
794
                    res >>= 1;
795

    
796
                    if (cur_k) {
797
                        res <<= cur_k;
798
                        res  |= get_bits_long(gb, cur_k);
799
                    }
800
                }
801

    
802
                *current_res++ = res;
803
            }
804
        }
805
    } else {
806
        current_res = bd->raw_samples + start;
807

    
808
        for (sb = 0; sb < sub_blocks; sb++, start = 0)
809
            for (; start < sb_length; start++)
810
                *current_res++ = decode_rice(gb, s[sb]);
811
     }
812

    
813
    if (!sconf->mc_coding || ctx->js_switch)
814
        align_get_bits(gb);
815

    
816
    return 0;
817
}
818

    
819

    
820
/** Decodes the block data for a non-constant block
821
 */
822
static int decode_var_block_data(ALSDecContext *ctx, ALSBlockData *bd)
823
{
824
    ALSSpecificConfig *sconf = &ctx->sconf;
825
    unsigned int block_length = bd->block_length;
826
    unsigned int smp = 0;
827
    unsigned int k;
828
    int opt_order             = bd->opt_order;
829
    int sb;
830
    int64_t y;
831
    int32_t *quant_cof        = bd->quant_cof;
832
    int32_t *lpc_cof          = bd->lpc_cof;
833
    int32_t *raw_samples      = bd->raw_samples;
834
    int32_t *raw_samples_end  = bd->raw_samples + bd->block_length;
835
    int32_t *lpc_cof_reversed = ctx->lpc_cof_reversed_buffer;
836

    
837
    // reverse long-term prediction
838
    if (*bd->use_ltp) {
839
        int ltp_smp;
840

    
841
        for (ltp_smp = FFMAX(*bd->ltp_lag - 2, 0); ltp_smp < block_length; ltp_smp++) {
842
            int center = ltp_smp - *bd->ltp_lag;
843
            int begin  = FFMAX(0, center - 2);
844
            int end    = center + 3;
845
            int tab    = 5 - (end - begin);
846
            int base;
847

    
848
            y = 1 << 6;
849

    
850
            for (base = begin; base < end; base++, tab++)
851
                y += MUL64(bd->ltp_gain[tab], raw_samples[base]);
852

    
853
            raw_samples[ltp_smp] += y >> 7;
854
        }
855
    }
856

    
857
    // reconstruct all samples from residuals
858
    if (bd->ra_block) {
859
        for (smp = 0; smp < opt_order; smp++) {
860
            y = 1 << 19;
861

    
862
            for (sb = 0; sb < smp; sb++)
863
                y += MUL64(lpc_cof[sb], raw_samples[-(sb + 1)]);
864

    
865
            *raw_samples++ -= y >> 20;
866
            parcor_to_lpc(smp, quant_cof, lpc_cof);
867
        }
868
    } else {
869
        for (k = 0; k < opt_order; k++)
870
            parcor_to_lpc(k, quant_cof, lpc_cof);
871

    
872
        // store previous samples in case that they have to be altered
873
        if (bd->store_prev_samples)
874
            memcpy(bd->prev_raw_samples, raw_samples - sconf->max_order,
875
                   sizeof(*bd->prev_raw_samples) * sconf->max_order);
876

    
877
        // reconstruct difference signal for prediction (joint-stereo)
878
        if (bd->js_blocks && bd->raw_other) {
879
            int32_t *left, *right;
880

    
881
            if (bd->raw_other > raw_samples) {  // D = R - L
882
                left  = raw_samples;
883
                right = bd->raw_other;
884
            } else {                                // D = R - L
885
                left  = bd->raw_other;
886
                right = raw_samples;
887
            }
888

    
889
            for (sb = -1; sb >= -sconf->max_order; sb--)
890
                raw_samples[sb] = right[sb] - left[sb];
891
        }
892

    
893
        // reconstruct shifted signal
894
        if (bd->shift_lsbs)
895
            for (sb = -1; sb >= -sconf->max_order; sb--)
896
                raw_samples[sb] >>= bd->shift_lsbs;
897
    }
898

    
899
    // reverse linear prediction coefficients for efficiency
900
    lpc_cof = lpc_cof + opt_order;
901

    
902
    for (sb = 0; sb < opt_order; sb++)
903
        lpc_cof_reversed[sb] = lpc_cof[-(sb + 1)];
904

    
905
    // reconstruct raw samples
906
    raw_samples = bd->raw_samples + smp;
907
    lpc_cof     = lpc_cof_reversed + opt_order;
908

    
909
    for (; raw_samples < raw_samples_end; raw_samples++) {
910
        y = 1 << 19;
911

    
912
        for (sb = -opt_order; sb < 0; sb++)
913
            y += MUL64(lpc_cof[sb], raw_samples[sb]);
914

    
915
        *raw_samples -= y >> 20;
916
    }
917

    
918
    raw_samples = bd->raw_samples;
919

    
920
    // restore previous samples in case that they have been altered
921
    if (bd->store_prev_samples)
922
        memcpy(raw_samples - sconf->max_order, bd->prev_raw_samples,
923
               sizeof(*raw_samples) * sconf->max_order);
924

    
925
    return 0;
926
}
927

    
928

    
929
/** Reads the block data.
930
 */
931
static int read_block(ALSDecContext *ctx, ALSBlockData *bd)
932
{
933
    GetBitContext *gb        = &ctx->gb;
934

    
935
    // read block type flag and read the samples accordingly
936
    if (get_bits1(gb)) {
937
        if (read_var_block_data(ctx, bd))
938
            return -1;
939
    } else {
940
        read_const_block_data(ctx, bd);
941
    }
942

    
943
    return 0;
944
}
945

    
946

    
947
/** Decodes the block data.
948
 */
949
static int decode_block(ALSDecContext *ctx, ALSBlockData *bd)
950
{
951
    unsigned int smp;
952

    
953
    // read block type flag and read the samples accordingly
954
    if (bd->const_block)
955
        decode_const_block_data(ctx, bd);
956
    else if (decode_var_block_data(ctx, bd))
957
        return -1;
958

    
959
    // TODO: read RLSLMS extension data
960

    
961
    if (bd->shift_lsbs)
962
        for (smp = 0; smp < bd->block_length; smp++)
963
            bd->raw_samples[smp] <<= bd->shift_lsbs;
964

    
965
    return 0;
966
}
967

    
968

    
969
/** Reads and decodes block data successively.
970
 */
971
static int read_decode_block(ALSDecContext *ctx, ALSBlockData *bd)
972
{
973
    int ret;
974

    
975
    ret = read_block(ctx, bd);
976

    
977
    if (ret)
978
        return ret;
979

    
980
    ret = decode_block(ctx, bd);
981

    
982
    return ret;
983
}
984

    
985

    
986
/** Computes the number of samples left to decode for the current frame and
987
 *  sets these samples to zero.
988
 */
989
static void zero_remaining(unsigned int b, unsigned int b_max,
990
                           const unsigned int *div_blocks, int32_t *buf)
991
{
992
    unsigned int count = 0;
993

    
994
    while (b < b_max)
995
        count += div_blocks[b];
996

    
997
    if (count)
998
        memset(buf, 0, sizeof(*buf) * count);
999
}
1000

    
1001

    
1002
/** Decodes blocks independently.
1003
 */
1004
static int decode_blocks_ind(ALSDecContext *ctx, unsigned int ra_frame,
1005
                             unsigned int c, const unsigned int *div_blocks,
1006
                             unsigned int *js_blocks)
1007
{
1008
    unsigned int b;
1009
    ALSBlockData bd;
1010

    
1011
    memset(&bd, 0, sizeof(ALSBlockData));
1012

    
1013
    bd.ra_block         = ra_frame;
1014
    bd.use_ltp          = ctx->use_ltp;
1015
    bd.ltp_lag          = ctx->ltp_lag;
1016
    bd.ltp_gain         = ctx->ltp_gain[0];
1017
    bd.quant_cof        = ctx->quant_cof[0];
1018
    bd.lpc_cof          = ctx->lpc_cof[0];
1019
    bd.prev_raw_samples = ctx->prev_raw_samples;
1020
    bd.raw_samples      = ctx->raw_samples[c];
1021

    
1022

    
1023
    for (b = 0; b < ctx->num_blocks; b++) {
1024
        bd.shift_lsbs       = 0;
1025
        bd.block_length     = div_blocks[b];
1026

    
1027
        if (read_decode_block(ctx, &bd)) {
1028
            // damaged block, write zero for the rest of the frame
1029
            zero_remaining(b, ctx->num_blocks, div_blocks, bd.raw_samples);
1030
            return -1;
1031
        }
1032
        bd.raw_samples += div_blocks[b];
1033
        bd.ra_block     = 0;
1034
    }
1035

    
1036
    return 0;
1037
}
1038

    
1039

    
1040
/** Decodes blocks dependently.
1041
 */
1042
static int decode_blocks(ALSDecContext *ctx, unsigned int ra_frame,
1043
                         unsigned int c, const unsigned int *div_blocks,
1044
                         unsigned int *js_blocks)
1045
{
1046
    ALSSpecificConfig *sconf = &ctx->sconf;
1047
    unsigned int offset = 0;
1048
    unsigned int b;
1049
    ALSBlockData bd[2];
1050

    
1051
    memset(bd, 0, 2 * sizeof(ALSBlockData));
1052

    
1053
    bd[0].ra_block         = ra_frame;
1054
    bd[0].use_ltp          = ctx->use_ltp;
1055
    bd[0].ltp_lag          = ctx->ltp_lag;
1056
    bd[0].ltp_gain         = ctx->ltp_gain[0];
1057
    bd[0].quant_cof        = ctx->quant_cof[0];
1058
    bd[0].lpc_cof          = ctx->lpc_cof[0];
1059
    bd[0].prev_raw_samples = ctx->prev_raw_samples;
1060
    bd[0].js_blocks        = *js_blocks;
1061

    
1062
    bd[1].ra_block         = ra_frame;
1063
    bd[1].use_ltp          = ctx->use_ltp;
1064
    bd[1].ltp_lag          = ctx->ltp_lag;
1065
    bd[1].ltp_gain         = ctx->ltp_gain[0];
1066
    bd[1].quant_cof        = ctx->quant_cof[0];
1067
    bd[1].lpc_cof          = ctx->lpc_cof[0];
1068
    bd[1].prev_raw_samples = ctx->prev_raw_samples;
1069
    bd[1].js_blocks        = *(js_blocks + 1);
1070

    
1071
    // decode all blocks
1072
    for (b = 0; b < ctx->num_blocks; b++) {
1073
        unsigned int s;
1074

    
1075
        bd[0].shift_lsbs   = 0;
1076
        bd[1].shift_lsbs   = 0;
1077

    
1078
        bd[0].block_length = div_blocks[b];
1079
        bd[1].block_length = div_blocks[b];
1080

    
1081
        bd[0].raw_samples  = ctx->raw_samples[c    ] + offset;
1082
        bd[1].raw_samples  = ctx->raw_samples[c + 1] + offset;
1083

    
1084
        bd[0].raw_other    = bd[1].raw_samples;
1085
        bd[1].raw_other    = bd[0].raw_samples;
1086

    
1087
        if(read_decode_block(ctx, &bd[0]) || read_decode_block(ctx, &bd[1])) {
1088
            // damaged block, write zero for the rest of the frame
1089
            zero_remaining(b, ctx->num_blocks, div_blocks, bd[0].raw_samples);
1090
            zero_remaining(b, ctx->num_blocks, div_blocks, bd[1].raw_samples);
1091
            return -1;
1092
        }
1093

    
1094
        // reconstruct joint-stereo blocks
1095
        if (bd[0].js_blocks) {
1096
            if (bd[1].js_blocks)
1097
                av_log(ctx->avctx, AV_LOG_WARNING, "Invalid channel pair!\n");
1098

    
1099
            for (s = 0; s < div_blocks[b]; s++)
1100
                bd[0].raw_samples[s] = bd[1].raw_samples[s] - bd[0].raw_samples[s];
1101
        } else if (bd[1].js_blocks) {
1102
            for (s = 0; s < div_blocks[b]; s++)
1103
                bd[1].raw_samples[s] = bd[1].raw_samples[s] + bd[0].raw_samples[s];
1104
        }
1105

    
1106
        offset  += div_blocks[b];
1107
        bd[0].ra_block = 0;
1108
        bd[1].ra_block = 0;
1109
    }
1110

    
1111
    // store carryover raw samples,
1112
    // the others channel raw samples are stored by the calling function.
1113
    memmove(ctx->raw_samples[c] - sconf->max_order,
1114
            ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,
1115
            sizeof(*ctx->raw_samples[c]) * sconf->max_order);
1116

    
1117
    return 0;
1118
}
1119

    
1120

    
1121
/** Reads the channel data.
1122
  */
1123
static int read_channel_data(ALSDecContext *ctx, ALSChannelData *cd, int c)
1124
{
1125
    GetBitContext *gb       = &ctx->gb;
1126
    ALSChannelData *current = cd;
1127
    unsigned int channels   = ctx->avctx->channels;
1128
    int entries             = 0;
1129

    
1130
    while (entries < channels && !(current->stop_flag = get_bits1(gb))) {
1131
        current->master_channel = get_bits_long(gb, av_ceil_log2(channels));
1132

    
1133
        if (current->master_channel >= channels) {
1134
            av_log(ctx->avctx, AV_LOG_ERROR, "Invalid master channel!\n");
1135
            return -1;
1136
        }
1137

    
1138
        if (current->master_channel != c) {
1139
            current->time_diff_flag = get_bits1(gb);
1140
            current->weighting[0]   = mcc_weightings[av_clip(decode_rice(gb, 1) + 16, 0, 32)];
1141
            current->weighting[1]   = mcc_weightings[av_clip(decode_rice(gb, 2) + 14, 0, 32)];
1142
            current->weighting[2]   = mcc_weightings[av_clip(decode_rice(gb, 1) + 16, 0, 32)];
1143

    
1144
            if (current->time_diff_flag) {
1145
                current->weighting[3] = mcc_weightings[av_clip(decode_rice(gb, 1) + 16, 0, 32)];
1146
                current->weighting[4] = mcc_weightings[av_clip(decode_rice(gb, 1) + 16, 0, 32)];
1147
                current->weighting[5] = mcc_weightings[av_clip(decode_rice(gb, 1) + 16, 0, 32)];
1148

    
1149
                current->time_diff_sign  = get_bits1(gb);
1150
                current->time_diff_index = get_bits(gb, ctx->ltp_lag_length - 3) + 3;
1151
            }
1152
        }
1153

    
1154
        current++;
1155
        entries++;
1156
    }
1157

    
1158
    if (entries == channels) {
1159
        av_log(ctx->avctx, AV_LOG_ERROR, "Damaged channel data!\n");
1160
        return -1;
1161
    }
1162

    
1163
    align_get_bits(gb);
1164
    return 0;
1165
}
1166

    
1167

    
1168
/** Recursively reverts the inter-channel correlation for a block.
1169
 */
1170
static int revert_channel_correlation(ALSDecContext *ctx, ALSBlockData *bd,
1171
                                       ALSChannelData **cd, int *reverted,
1172
                                       unsigned int offset, int c)
1173
{
1174
    ALSChannelData *ch = cd[c];
1175
    unsigned int   dep = 0;
1176
    unsigned int channels = ctx->avctx->channels;
1177

    
1178
    if (reverted[c])
1179
        return 0;
1180

    
1181
    reverted[c] = 1;
1182

    
1183
    while (dep < channels && !ch[dep].stop_flag) {
1184
        revert_channel_correlation(ctx, bd, cd, reverted, offset,
1185
                                   ch[dep].master_channel);
1186

    
1187
        dep++;
1188
    }
1189

    
1190
    if (dep == channels) {
1191
        av_log(ctx->avctx, AV_LOG_WARNING, "Invalid channel correlation!\n");
1192
        return -1;
1193
    }
1194

    
1195
    bd->use_ltp     = ctx->use_ltp + c;
1196
    bd->ltp_lag     = ctx->ltp_lag + c;
1197
    bd->ltp_gain    = ctx->ltp_gain[c];
1198
    bd->lpc_cof     = ctx->lpc_cof[c];
1199
    bd->quant_cof   = ctx->quant_cof[c];
1200
    bd->raw_samples = ctx->raw_samples[c] + offset;
1201

    
1202
    dep = 0;
1203
    while (!ch[dep].stop_flag) {
1204
        unsigned int smp;
1205
        unsigned int begin = 1;
1206
        unsigned int end   = bd->block_length - 1;
1207
        int64_t y;
1208
        int32_t *master = ctx->raw_samples[ch[dep].master_channel] + offset;
1209

    
1210
        if (ch[dep].time_diff_flag) {
1211
            int t = ch[dep].time_diff_index;
1212

    
1213
            if (ch[dep].time_diff_sign) {
1214
                t      = -t;
1215
                begin -= t;
1216
            } else {
1217
                end   -= t;
1218
            }
1219

    
1220
            for (smp = begin; smp < end; smp++) {
1221
                y  = (1 << 6) +
1222
                     MUL64(ch[dep].weighting[0], master[smp - 1    ]) +
1223
                     MUL64(ch[dep].weighting[1], master[smp        ]) +
1224
                     MUL64(ch[dep].weighting[2], master[smp + 1    ]) +
1225
                     MUL64(ch[dep].weighting[3], master[smp - 1 + t]) +
1226
                     MUL64(ch[dep].weighting[4], master[smp     + t]) +
1227
                     MUL64(ch[dep].weighting[5], master[smp + 1 + t]);
1228

    
1229
                bd->raw_samples[smp] += y >> 7;
1230
            }
1231
        } else {
1232
            for (smp = begin; smp < end; smp++) {
1233
                y  = (1 << 6) +
1234
                     MUL64(ch[dep].weighting[0], master[smp - 1]) +
1235
                     MUL64(ch[dep].weighting[1], master[smp    ]) +
1236
                     MUL64(ch[dep].weighting[2], master[smp + 1]);
1237

    
1238
                bd->raw_samples[smp] += y >> 7;
1239
            }
1240
        }
1241

    
1242
        dep++;
1243
    }
1244

    
1245
    return 0;
1246
}
1247

    
1248

    
1249
/** Reads the frame data.
1250
 */
1251
static int read_frame_data(ALSDecContext *ctx, unsigned int ra_frame)
1252
{
1253
    ALSSpecificConfig *sconf = &ctx->sconf;
1254
    AVCodecContext *avctx    = ctx->avctx;
1255
    GetBitContext *gb = &ctx->gb;
1256
    unsigned int div_blocks[32];                ///< block sizes.
1257
    unsigned int c;
1258
    unsigned int js_blocks[2];
1259

    
1260
    uint32_t bs_info = 0;
1261

    
1262
    // skip the size of the ra unit if present in the frame
1263
    if (sconf->ra_flag == RA_FLAG_FRAMES && ra_frame)
1264
        skip_bits_long(gb, 32);
1265

    
1266
    if (sconf->mc_coding && sconf->joint_stereo) {
1267
        ctx->js_switch = get_bits1(gb);
1268
        align_get_bits(gb);
1269
    }
1270

    
1271
    if (!sconf->mc_coding || ctx->js_switch) {
1272
        int independent_bs = !sconf->joint_stereo;
1273

    
1274
        for (c = 0; c < avctx->channels; c++) {
1275
            js_blocks[0] = 0;
1276
            js_blocks[1] = 0;
1277

    
1278
            get_block_sizes(ctx, div_blocks, &bs_info);
1279

    
1280
            // if joint_stereo and block_switching is set, independent decoding
1281
            // is signaled via the first bit of bs_info
1282
            if (sconf->joint_stereo && sconf->block_switching)
1283
                if (bs_info >> 31)
1284
                    independent_bs = 2;
1285

    
1286
            // if this is the last channel, it has to be decoded independently
1287
            if (c == avctx->channels - 1)
1288
                independent_bs = 1;
1289

    
1290
            if (independent_bs) {
1291
                if (decode_blocks_ind(ctx, ra_frame, c, div_blocks, js_blocks))
1292
                    return -1;
1293

    
1294
                independent_bs--;
1295
            } else {
1296
                if (decode_blocks(ctx, ra_frame, c, div_blocks, js_blocks))
1297
                    return -1;
1298

    
1299
                c++;
1300
            }
1301

    
1302
            // store carryover raw samples
1303
            memmove(ctx->raw_samples[c] - sconf->max_order,
1304
                    ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,
1305
                    sizeof(*ctx->raw_samples[c]) * sconf->max_order);
1306
        }
1307
    } else { // multi-channel coding
1308
        ALSBlockData   bd;
1309
        int            b;
1310
        int            *reverted_channels = ctx->reverted_channels;
1311
        unsigned int   offset             = 0;
1312

    
1313
        for (c = 0; c < avctx->channels; c++)
1314
            if (ctx->chan_data[c] < ctx->chan_data_buffer) {
1315
                av_log(ctx->avctx, AV_LOG_ERROR, "Invalid channel data!\n");
1316
                return -1;
1317
            }
1318

    
1319
        memset(&bd,               0, sizeof(ALSBlockData));
1320
        memset(reverted_channels, 0, sizeof(*reverted_channels) * avctx->channels);
1321

    
1322
        bd.ra_block         = ra_frame;
1323
        bd.prev_raw_samples = ctx->prev_raw_samples;
1324

    
1325
        get_block_sizes(ctx, div_blocks, &bs_info);
1326

    
1327
        for (b = 0; b < ctx->num_blocks; b++) {
1328
            bd.shift_lsbs   = 0;
1329
            bd.block_length = div_blocks[b];
1330

    
1331
            for (c = 0; c < avctx->channels; c++) {
1332
                bd.use_ltp     = ctx->use_ltp + c;
1333
                bd.ltp_lag     = ctx->ltp_lag + c;
1334
                bd.ltp_gain    = ctx->ltp_gain[c];
1335
                bd.lpc_cof     = ctx->lpc_cof[c];
1336
                bd.quant_cof   = ctx->quant_cof[c];
1337
                bd.raw_samples = ctx->raw_samples[c] + offset;
1338
                bd.raw_other   = NULL;
1339

    
1340
                read_block(ctx, &bd);
1341
                if (read_channel_data(ctx, ctx->chan_data[c], c))
1342
                    return -1;
1343
            }
1344

    
1345
            for (c = 0; c < avctx->channels; c++)
1346
                if (revert_channel_correlation(ctx, &bd, ctx->chan_data,
1347
                                               reverted_channels, offset, c))
1348
                    return -1;
1349

    
1350
            for (c = 0; c < avctx->channels; c++) {
1351
                bd.use_ltp     = ctx->use_ltp + c;
1352
                bd.ltp_lag     = ctx->ltp_lag + c;
1353
                bd.ltp_gain    = ctx->ltp_gain[c];
1354
                bd.lpc_cof     = ctx->lpc_cof[c];
1355
                bd.quant_cof   = ctx->quant_cof[c];
1356
                bd.raw_samples = ctx->raw_samples[c] + offset;
1357
                decode_block(ctx, &bd);
1358
            }
1359

    
1360
            memset(reverted_channels, 0, avctx->channels * sizeof(*reverted_channels));
1361
            offset      += div_blocks[b];
1362
            bd.ra_block  = 0;
1363
        }
1364

    
1365
        // store carryover raw samples
1366
        for (c = 0; c < avctx->channels; c++)
1367
            memmove(ctx->raw_samples[c] - sconf->max_order,
1368
                    ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,
1369
                    sizeof(*ctx->raw_samples[c]) * sconf->max_order);
1370
    }
1371

    
1372
    // TODO: read_diff_float_data
1373

    
1374
    return 0;
1375
}
1376

    
1377

    
1378
/** Decodes an ALS frame.
1379
 */
1380
static int decode_frame(AVCodecContext *avctx,
1381
                        void *data, int *data_size,
1382
                        AVPacket *avpkt)
1383
{
1384
    ALSDecContext *ctx       = avctx->priv_data;
1385
    ALSSpecificConfig *sconf = &ctx->sconf;
1386
    const uint8_t *buffer    = avpkt->data;
1387
    int buffer_size          = avpkt->size;
1388
    int invalid_frame, size;
1389
    unsigned int c, sample, ra_frame, bytes_read, shift;
1390

    
1391
    init_get_bits(&ctx->gb, buffer, buffer_size * 8);
1392

    
1393
    // In the case that the distance between random access frames is set to zero
1394
    // (sconf->ra_distance == 0) no frame is treated as a random access frame.
1395
    // For the first frame, if prediction is used, all samples used from the
1396
    // previous frame are assumed to be zero.
1397
    ra_frame = sconf->ra_distance && !(ctx->frame_id % sconf->ra_distance);
1398

    
1399
    // the last frame to decode might have a different length
1400
    if (sconf->samples != 0xFFFFFFFF)
1401
        ctx->cur_frame_length = FFMIN(sconf->samples - ctx->frame_id * (uint64_t) sconf->frame_length,
1402
                                      sconf->frame_length);
1403
    else
1404
        ctx->cur_frame_length = sconf->frame_length;
1405

    
1406
    // decode the frame data
1407
    if ((invalid_frame = read_frame_data(ctx, ra_frame) < 0))
1408
        av_log(ctx->avctx, AV_LOG_WARNING,
1409
               "Reading frame data failed. Skipping RA unit.\n");
1410

    
1411
    ctx->frame_id++;
1412

    
1413
    // check for size of decoded data
1414
    size = ctx->cur_frame_length * avctx->channels *
1415
           (av_get_bits_per_sample_format(avctx->sample_fmt) >> 3);
1416

    
1417
    if (size > *data_size) {
1418
        av_log(avctx, AV_LOG_ERROR, "Decoded data exceeds buffer size.\n");
1419
        return -1;
1420
    }
1421

    
1422
    *data_size = size;
1423

    
1424
    // transform decoded frame into output format
1425
    #define INTERLEAVE_OUTPUT(bps)                                 \
1426
    {                                                              \
1427
        int##bps##_t *dest = (int##bps##_t*) data;                 \
1428
        shift = bps - ctx->avctx->bits_per_raw_sample;             \
1429
        for (sample = 0; sample < ctx->cur_frame_length; sample++) \
1430
            for (c = 0; c < avctx->channels; c++)                  \
1431
                *dest++ = ctx->raw_samples[c][sample] << shift;    \
1432
    }
1433

    
1434
    if (ctx->avctx->bits_per_raw_sample <= 16) {
1435
        INTERLEAVE_OUTPUT(16)
1436
    } else {
1437
        INTERLEAVE_OUTPUT(32)
1438
    }
1439

    
1440
    bytes_read = invalid_frame ? buffer_size :
1441
                                 (get_bits_count(&ctx->gb) + 7) >> 3;
1442

    
1443
    return bytes_read;
1444
}
1445

    
1446

    
1447
/** Uninitializes the ALS decoder.
1448
 */
1449
static av_cold int decode_end(AVCodecContext *avctx)
1450
{
1451
    ALSDecContext *ctx = avctx->priv_data;
1452

    
1453
    av_freep(&ctx->sconf.chan_pos);
1454

    
1455
    ff_bgmc_end(&ctx->bgmc_lut, &ctx->bgmc_lut_status);
1456

    
1457
    av_freep(&ctx->use_ltp);
1458
    av_freep(&ctx->ltp_lag);
1459
    av_freep(&ctx->ltp_gain);
1460
    av_freep(&ctx->ltp_gain_buffer);
1461
    av_freep(&ctx->quant_cof);
1462
    av_freep(&ctx->lpc_cof);
1463
    av_freep(&ctx->quant_cof_buffer);
1464
    av_freep(&ctx->lpc_cof_buffer);
1465
    av_freep(&ctx->lpc_cof_reversed_buffer);
1466
    av_freep(&ctx->prev_raw_samples);
1467
    av_freep(&ctx->raw_samples);
1468
    av_freep(&ctx->raw_buffer);
1469
    av_freep(&ctx->chan_data);
1470
    av_freep(&ctx->chan_data_buffer);
1471
    av_freep(&ctx->reverted_channels);
1472

    
1473
    return 0;
1474
}
1475

    
1476

    
1477
/** Initializes the ALS decoder.
1478
 */
1479
static av_cold int decode_init(AVCodecContext *avctx)
1480
{
1481
    unsigned int c;
1482
    unsigned int channel_size;
1483
    int num_buffers;
1484
    ALSDecContext *ctx = avctx->priv_data;
1485
    ALSSpecificConfig *sconf = &ctx->sconf;
1486
    ctx->avctx = avctx;
1487

    
1488
    if (!avctx->extradata) {
1489
        av_log(avctx, AV_LOG_ERROR, "Missing required ALS extradata.\n");
1490
        return -1;
1491
    }
1492

    
1493
    if (read_specific_config(ctx)) {
1494
        av_log(avctx, AV_LOG_ERROR, "Reading ALSSpecificConfig failed.\n");
1495
        decode_end(avctx);
1496
        return -1;
1497
    }
1498

    
1499
    if (check_specific_config(ctx)) {
1500
        decode_end(avctx);
1501
        return -1;
1502
    }
1503

    
1504
    if (sconf->bgmc)
1505
        ff_bgmc_init(avctx, &ctx->bgmc_lut, &ctx->bgmc_lut_status);
1506

    
1507
    if (sconf->floating) {
1508
        avctx->sample_fmt          = SAMPLE_FMT_FLT;
1509
        avctx->bits_per_raw_sample = 32;
1510
    } else {
1511
        avctx->sample_fmt          = sconf->resolution > 1
1512
                                     ? SAMPLE_FMT_S32 : SAMPLE_FMT_S16;
1513
        avctx->bits_per_raw_sample = (sconf->resolution + 1) * 8;
1514
    }
1515

    
1516
    // set maximum Rice parameter for progressive decoding based on resolution
1517
    // This is not specified in 14496-3 but actually done by the reference
1518
    // codec RM22 revision 2.
1519
    ctx->s_max = sconf->resolution > 1 ? 31 : 15;
1520

    
1521
    // set lag value for long-term prediction
1522
    ctx->ltp_lag_length = 8 + (avctx->sample_rate >=  96000) +
1523
                              (avctx->sample_rate >= 192000);
1524

    
1525
    // allocate quantized parcor coefficient buffer
1526
    num_buffers = sconf->mc_coding ? avctx->channels : 1;
1527

    
1528
    ctx->quant_cof        = av_malloc(sizeof(*ctx->quant_cof) * num_buffers);
1529
    ctx->lpc_cof          = av_malloc(sizeof(*ctx->lpc_cof)   * num_buffers);
1530
    ctx->quant_cof_buffer = av_malloc(sizeof(*ctx->quant_cof_buffer) *
1531
                                      num_buffers * sconf->max_order);
1532
    ctx->lpc_cof_buffer   = av_malloc(sizeof(*ctx->lpc_cof_buffer) *
1533
                                      num_buffers * sconf->max_order);
1534
    ctx->lpc_cof_reversed_buffer = av_malloc(sizeof(*ctx->lpc_cof_buffer) *
1535
                                             sconf->max_order);
1536

    
1537
    if (!ctx->quant_cof              || !ctx->lpc_cof        ||
1538
        !ctx->quant_cof_buffer       || !ctx->lpc_cof_buffer ||
1539
        !ctx->lpc_cof_reversed_buffer) {
1540
        av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
1541
        return AVERROR(ENOMEM);
1542
    }
1543

    
1544
    // assign quantized parcor coefficient buffers
1545
    for (c = 0; c < num_buffers; c++) {
1546
        ctx->quant_cof[c] = ctx->quant_cof_buffer + c * sconf->max_order;
1547
        ctx->lpc_cof[c]   = ctx->lpc_cof_buffer   + c * sconf->max_order;
1548
    }
1549

    
1550
    // allocate and assign lag and gain data buffer for ltp mode
1551
    ctx->use_ltp         = av_mallocz(sizeof(*ctx->use_ltp)  * num_buffers);
1552
    ctx->ltp_lag         = av_malloc (sizeof(*ctx->ltp_lag)  * num_buffers);
1553
    ctx->ltp_gain        = av_malloc (sizeof(*ctx->ltp_gain) * num_buffers);
1554
    ctx->ltp_gain_buffer = av_malloc (sizeof(*ctx->ltp_gain_buffer) *
1555
                                      num_buffers * 5);
1556

    
1557
    if (!ctx->use_ltp  || !ctx->ltp_lag ||
1558
        !ctx->ltp_gain || !ctx->ltp_gain_buffer) {
1559
        av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
1560
        decode_end(avctx);
1561
        return AVERROR(ENOMEM);
1562
    }
1563

    
1564
    for (c = 0; c < num_buffers; c++)
1565
        ctx->ltp_gain[c] = ctx->ltp_gain_buffer + c * 5;
1566

    
1567
    // allocate and assign channel data buffer for mcc mode
1568
    if (sconf->mc_coding) {
1569
        ctx->chan_data_buffer  = av_malloc(sizeof(*ctx->chan_data_buffer) *
1570
                                           num_buffers * num_buffers);
1571
        ctx->chan_data         = av_malloc(sizeof(*ctx->chan_data) *
1572
                                           num_buffers);
1573
        ctx->reverted_channels = av_malloc(sizeof(*ctx->reverted_channels) *
1574
                                           num_buffers);
1575

    
1576
        if (!ctx->chan_data_buffer || !ctx->chan_data || !ctx->reverted_channels) {
1577
            av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
1578
            decode_end(avctx);
1579
            return AVERROR(ENOMEM);
1580
        }
1581

    
1582
        for (c = 0; c < num_buffers; c++)
1583
            ctx->chan_data[c] = ctx->chan_data_buffer + c * num_buffers;
1584
    } else {
1585
        ctx->chan_data         = NULL;
1586
        ctx->chan_data_buffer  = NULL;
1587
        ctx->reverted_channels = NULL;
1588
    }
1589

    
1590
    avctx->frame_size = sconf->frame_length;
1591
    channel_size      = sconf->frame_length + sconf->max_order;
1592

    
1593
    ctx->prev_raw_samples = av_malloc (sizeof(*ctx->prev_raw_samples) * sconf->max_order);
1594
    ctx->raw_buffer       = av_mallocz(sizeof(*ctx->     raw_buffer)  * avctx->channels * channel_size);
1595
    ctx->raw_samples      = av_malloc (sizeof(*ctx->     raw_samples) * avctx->channels);
1596

    
1597
    // allocate previous raw sample buffer
1598
    if (!ctx->prev_raw_samples || !ctx->raw_buffer|| !ctx->raw_samples) {
1599
        av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
1600
        decode_end(avctx);
1601
        return AVERROR(ENOMEM);
1602
    }
1603

    
1604
    // assign raw samples buffers
1605
    ctx->raw_samples[0] = ctx->raw_buffer + sconf->max_order;
1606
    for (c = 1; c < avctx->channels; c++)
1607
        ctx->raw_samples[c] = ctx->raw_samples[c - 1] + channel_size;
1608

    
1609
    return 0;
1610
}
1611

    
1612

    
1613
/** Flushes (resets) the frame ID after seeking.
1614
 */
1615
static av_cold void flush(AVCodecContext *avctx)
1616
{
1617
    ALSDecContext *ctx = avctx->priv_data;
1618

    
1619
    ctx->frame_id = 0;
1620
}
1621

    
1622

    
1623
AVCodec als_decoder = {
1624
    "als",
1625
    CODEC_TYPE_AUDIO,
1626
    CODEC_ID_MP4ALS,
1627
    sizeof(ALSDecContext),
1628
    decode_init,
1629
    NULL,
1630
    decode_end,
1631
    decode_frame,
1632
    .flush = flush,
1633
    .capabilities = CODEC_CAP_SUBFRAMES,
1634
    .long_name = NULL_IF_CONFIG_SMALL("MPEG-4 Audio Lossless Coding (ALS)"),
1635
};
1636