/proc/self/cwd/libfaad/rvlc.c

Source
/*
** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding
** Copyright (C) 2003-2005 M. Bakker, Nero AG, http://www.nero.com
**
** This program is free software; you can redistribute it and/or modify
** it under the terms of the GNU General Public License as published by
** the Free Software Foundation; either version 2 of the License, or
** (at your option) any later version.
**
** This program 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 General Public License for more details.
**
** You should have received a copy of the GNU General Public License
** along with this program; if not, write to the Free Software
** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
**
** Any non-GPL usage of this software or parts of this software is strictly
** forbidden.
**
** The "appropriate copyright message" mentioned in section 2c of the GPLv2
** must read: "Code from FAAD2 is copyright (c) Nero AG, www.nero.com"
**
** Commercial non-GPL licensing of this software is possible.
** For more info contact Nero AG through Mpeg4AAClicense@nero.com.
**
** $Id: rvlc.c,v 1.21 2007/11/01 12:33:34 menno Exp $
**/

/* RVLC scalefactor decoding
 *
 * RVLC works like this:
 *  1. Only symmetric huffman codewords are used
 *  2. Total length of the scalefactor data is stored in the bitsream
 *  3. Scalefactors are DPCM coded
 *  4. Next to the starting value for DPCM the ending value is also stored
 *
 * With all this it is possible to read the scalefactor data from 2 sides.
 * If there is a bit error in the scalefactor data it is possible to start
 * decoding from the other end of the data, to find all but 1 scalefactor.
 */

#include "common.h"
#include "structs.h"

#include <stdlib.h>

#include "syntax.h"
#include "bits.h"
#include "rvlc.h"


#ifdef ERROR_RESILIENCE

//#define PRINT_RVLC

/* static function declarations */
static uint8_t rvlc_decode_sf_forward(ic_stream *ics,
                                      bitfile *ld_sf,
                                      bitfile *ld_esc,
                                      uint8_t *is_used);
#if 0
static uint8_t rvlc_decode_sf_reverse(ic_stream *ics,
                                      bitfile *ld_sf,
                                      bitfile *ld_esc,
                                      uint8_t is_used);
#endif
static int8_t rvlc_huffman_sf(bitfile *ld_sf, bitfile *ld_esc /*,
                              int8_t direction*/);
static int8_t rvlc_huffman_esc(bitfile *ld_esc /*, int8_t direction*/);


uint8_t rvlc_scale_factor_data(ic_stream *ics, bitfile *ld)
{
    uint8_t bits = 9;

    ics->sf_concealment = faad_get1bit(ld
        DEBUGVAR(1,149,"rvlc_scale_factor_data(): sf_concealment"));
    ics->rev_global_gain = (uint8_t)faad_getbits(ld, 8
        DEBUGVAR(1,150,"rvlc_scale_factor_data(): rev_global_gain"));

    if (ics->window_sequence == EIGHT_SHORT_SEQUENCE)
        bits = 11;

    /* the number of bits used for the huffman codewords */
    ics->length_of_rvlc_sf = (uint16_t)faad_getbits(ld, bits
        DEBUGVAR(1,151,"rvlc_scale_factor_data(): length_of_rvlc_sf"));

    if (ics->noise_used)
    {
        ics->dpcm_noise_nrg = (uint16_t)faad_getbits(ld, 9
            DEBUGVAR(1,152,"rvlc_scale_factor_data(): dpcm_noise_nrg"));

        /* the 9 bits of dpcm_noise_nrg are counted in length_of_rvlc_sf, so a
           conformant value is at least 9; reject a smaller one before the
           unsigned subtraction wraps length_of_rvlc_sf to a huge value */
        if (ics->length_of_rvlc_sf < 9)
            return 8;

        ics->length_of_rvlc_sf -= 9;
    }

    ics->sf_escapes_present = faad_get1bit(ld
        DEBUGVAR(1,153,"rvlc_scale_factor_data(): sf_escapes_present"));

    if (ics->sf_escapes_present)
    {
        ics->length_of_rvlc_escapes = (uint8_t)faad_getbits(ld, 8
            DEBUGVAR(1,154,"rvlc_scale_factor_data(): length_of_rvlc_escapes"));
    }

    if (ics->noise_used)
    {
        ics->dpcm_noise_last_position = (uint16_t)faad_getbits(ld, 9
            DEBUGVAR(1,155,"rvlc_scale_factor_data(): dpcm_noise_last_position"));
    }

    return 0;
}

uint8_t rvlc_decode_scale_factors(ic_stream *ics, bitfile *ld)
{
    uint8_t result;
    uint8_t intensity_used = 0;
    uint8_t *rvlc_sf_buffer = NULL;
    uint8_t *rvlc_esc_buffer = NULL;
    bitfile ld_rvlc_sf = {0}, ld_rvlc_esc = {0};
//    bitfile ld_rvlc_sf_rev, ld_rvlc_esc_rev;

    if (ics->length_of_rvlc_sf > 0)
    {
        /* We read length_of_rvlc_sf bits here to put it in a
           seperate bitfile.
        */
        rvlc_sf_buffer = faad_getbitbuffer(ld, ics->length_of_rvlc_sf
            DEBUGVAR(1,156,"rvlc_decode_scale_factors(): bitbuffer: length_of_rvlc_sf"));

        faad_initbits(&ld_rvlc_sf, (void*)rvlc_sf_buffer, bit2byte(ics->length_of_rvlc_sf));
//        faad_initbits_rev(&ld_rvlc_sf_rev, (void*)rvlc_sf_buffer,
//            ics->length_of_rvlc_sf);
    }
    if ((ics->length_of_rvlc_sf == 0) || (ld_rvlc_sf.error != 0)) {
        memset(&ld_rvlc_sf, 0, sizeof(ld_rvlc_sf));
        ld_rvlc_sf.error = 1;
    }

    if (ics->sf_escapes_present)
    {
        /* We read length_of_rvlc_escapes bits here to put it in a
           seperate bitfile.
        */
        rvlc_esc_buffer = faad_getbitbuffer(ld, ics->length_of_rvlc_escapes
            DEBUGVAR(1,157,"rvlc_decode_scale_factors(): bitbuffer: length_of_rvlc_escapes"));

        faad_initbits(&ld_rvlc_esc, (void*)rvlc_esc_buffer, bit2byte(ics->length_of_rvlc_escapes));
//        faad_initbits_rev(&ld_rvlc_esc_rev, (void*)rvlc_esc_buffer,
//            ics->length_of_rvlc_escapes);
    }
    if (!ics->sf_escapes_present || (ld_rvlc_esc.error != 0)) {
        memset(&ld_rvlc_esc, 0, sizeof(ld_rvlc_esc));
        ld_rvlc_esc.error = 1;
    }

    /* decode the rvlc scale factors and escapes */
    result = rvlc_decode_sf_forward(ics, &ld_rvlc_sf,
        &ld_rvlc_esc, &intensity_used);
//    result = rvlc_decode_sf_reverse(ics, &ld_rvlc_sf_rev,
//        &ld_rvlc_esc_rev, intensity_used);


    if (rvlc_esc_buffer) faad_free(rvlc_esc_buffer);
    if (rvlc_sf_buffer) faad_free(rvlc_sf_buffer);

    if (ics->length_of_rvlc_sf > 0)
        faad_endbits(&ld_rvlc_sf);
    if (ics->sf_escapes_present)
        faad_endbits(&ld_rvlc_esc);

    return result;
}

static uint8_t rvlc_decode_sf_forward(ic_stream *ics, bitfile *ld_sf, bitfile *ld_esc,
                                      uint8_t *intensity_used)
{
    int8_t g, sfb;
    int8_t t = 0;
    int8_t error = ld_sf->error | ld_esc->error;
    int8_t noise_pcm_flag = 1;

    int16_t scale_factor = ics->global_gain;
    int16_t is_position = 0;
    int16_t noise_energy = ics->global_gain - 90 - 256;
    int16_t scale_factor_max = 255;
#ifdef FIXED_POINT
    /* TODO: consider rolling out to regular build. */
#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
    /* The value is inexact, adjusted to current fuzzer findings. */
    scale_factor_max = 165;
#endif  // FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
#endif  // FIXED_POINT

#ifdef PRINT_RVLC
    printf("\nglobal_gain: %d\n", ics->global_gain);
#endif

    for (g = 0; g < ics->num_window_groups; g++)
    {
        for (sfb = 0; sfb < ics->max_sfb; sfb++)
        {
            if (error)
            {
                ics->scale_factors[g][sfb] = 0;
            } else {
                switch (ics->sfb_cb[g][sfb])
                {
                case ZERO_HCB: /* zero book */
                    ics->scale_factors[g][sfb] = 0;
                    break;
                case INTENSITY_HCB: /* intensity books */
                case INTENSITY_HCB2:

                    *intensity_used = 1;

                    /* decode intensity position */
                    t = rvlc_huffman_sf(ld_sf, ld_esc /*, +1*/);

                    is_position += t;
                    ics->scale_factors[g][sfb] = is_position;

                    break;
                case NOISE_HCB: /* noise books */

                    /* decode noise energy */
                    if (noise_pcm_flag)
                    {
                        int16_t n = ics->dpcm_noise_nrg;
                        noise_pcm_flag = 0;
                        noise_energy += n;
                    } else {
                        t = rvlc_huffman_sf(ld_sf, ld_esc /*, +1*/);
                        noise_energy += t;
                    }

                    ics->scale_factors[g][sfb] = noise_energy;

                    break;
                default: /* spectral books */

                    /* decode scale factor */
                    t = rvlc_huffman_sf(ld_sf, ld_esc /*, +1*/);

                    scale_factor += t;
                    if (scale_factor < 0 || scale_factor > 255)
                        return 4;

                    ics->scale_factors[g][sfb] = min(scale_factor, scale_factor_max);

                    break;
                }
#ifdef PRINT_RVLC
                printf("%3d:%4d%4d\n", sfb, ics->sfb_cb[g][sfb],
                    ics->scale_factors[g][sfb]);
#endif
                if (t == 99)
                {
                    error = 1;
                }
            }
        }
    }
#ifdef PRINT_RVLC
    printf("\n\n");
#endif

    return 0;
}

#if 0 // not used right now, doesn't work correctly yet
static uint8_t rvlc_decode_sf_reverse(ic_stream *ics, bitfile *ld_sf, bitfile *ld_esc,
                                      uint8_t intensity_used)
{
    int8_t g, sfb;
    int8_t t = 0;
    int8_t error = 0;
    int8_t noise_pcm_flag = 1, is_pcm_flag = 1, sf_pcm_flag = 1;

    int16_t scale_factor = ics->rev_global_gain;
    int16_t is_position = 0;
    int16_t noise_energy = ics->rev_global_gain;

#ifdef PRINT_RVLC
    printf("\nrev_global_gain: %d\n", ics->rev_global_gain);
#endif

    if (intensity_used)
    {
        is_position = rvlc_huffman_sf(ld_sf, ld_esc, -1);
#ifdef PRINT_RVLC
        printf("is_position: %d\n", is_position);
#endif
    }

    for (g = ics->num_window_groups-1; g >= 0; g--)
    {
        for (sfb = ics->max_sfb-1; sfb >= 0; sfb--)
        {
            if (error)
            {
                ics->scale_factors[g][sfb] = 0;
            } else {
                switch (ics->sfb_cb[g][sfb])
                {
                case ZERO_HCB: /* zero book */
                    ics->scale_factors[g][sfb] = 0;
                    break;
                case INTENSITY_HCB: /* intensity books */
                case INTENSITY_HCB2:

                    if (is_pcm_flag)
                    {
                        is_pcm_flag = 0;
                        ics->scale_factors[g][sfb] = is_position;
                    } else {
                        t = rvlc_huffman_sf(ld_sf, ld_esc, -1);
                        is_position -= t;

                        ics->scale_factors[g][sfb] = (uint8_t)is_position;
                    }
                    break;
                case NOISE_HCB: /* noise books */

                    /* decode noise energy */
                    if (noise_pcm_flag)
                    {
                        noise_pcm_flag = 0;
                        noise_energy = ics->dpcm_noise_last_position;
                    } else {
                        t = rvlc_huffman_sf(ld_sf, ld_esc, -1);
                        noise_energy -= t;
                    }

                    ics->scale_factors[g][sfb] = (uint8_t)noise_energy;
                    break;
                default: /* spectral books */

                    if (sf_pcm_flag || (sfb == 0))
                    {
                        sf_pcm_flag = 0;
                        if (sfb == 0)
                            scale_factor = ics->global_gain;
                    } else {
                        /* decode scale factor */
                        t = rvlc_huffman_sf(ld_sf, ld_esc, -1);
                        scale_factor -= t;
                    }

                    if (scale_factor < 0)
                        return 4;

                    ics->scale_factors[g][sfb] = (uint8_t)scale_factor;
                    break;
                }
#ifdef PRINT_RVLC
                printf("%3d:%4d%4d\n", sfb, ics->sfb_cb[g][sfb],
                    ics->scale_factors[g][sfb]);
#endif
                if (t == 99)
                {
                    error = 1;
                }
            }
        }
    }

#ifdef PRINT_RVLC
    printf("\n\n");
#endif

    return 0;
}
#endif

/* index == 99 means not allowed codeword */
static rvlc_huff_table book_rvlc[] = {
    /*index  length  codeword */
    {  0, 1,   0 }, /*         0 */
    { -1, 3,   5 }, /*       101 */
    {  1, 3,   7 }, /*       111 */
    { -2, 4,   9 }, /*      1001 */
    { -3, 5,  17 }, /*     10001 */
    {  2, 5,  27 }, /*     11011 */
    { -4, 6,  33 }, /*    100001 */
    { 99, 6,  50 }, /*    110010 */
    {  3, 6,  51 }, /*    110011 */
    { 99, 6,  52 }, /*    110100 */
    { -7, 7,  65 }, /*   1000001 */
    { 99, 7,  96 }, /*   1100000 */
    { 99, 7,  98 }, /*   1100010 */
    {  7, 7,  99 }, /*   1100011 */
    {  4, 7, 107 }, /*   1101011 */
    { -5, 8, 129 }, /*  10000001 */
    { 99, 8, 194 }, /*  11000010 */
    {  5, 8, 195 }, /*  11000011 */
    { 99, 8, 212 }, /*  11010100 */
    { 99, 9, 256 }, /* 100000000 */
    { -6, 9, 257 }, /* 100000001 */
    { 99, 9, 426 }, /* 110101010 */
    {  6, 9, 427 }, /* 110101011 */
    { 99, 10,  0 } /* Shouldn't come this far */
};

static rvlc_huff_table book_escape[] = {
    /*index  length  codeword */
    { 1, 2, 0 },
    { 0, 2, 2 },
    { 3, 3, 2 },
    { 2, 3, 6 },
    { 4, 4, 14 },
    { 7, 5, 13 },
    { 6, 5, 15 },
    { 5, 5, 31 },
    { 11, 6, 24 },
    { 10, 6, 25 },
    { 9, 6, 29 },
    { 8, 6, 61 },
    { 13, 7, 56  },
    { 12, 7, 120 },
    { 15, 8, 114 },
    { 14, 8, 242 },
    { 17, 9, 230 },
    { 16, 9, 486 },
    { 19, 10, 463  },
    { 18, 10, 974  },
    { 22, 11, 925  },
    { 20, 11, 1950 },
    { 21, 11, 1951 },
    { 23, 12, 1848 },
    { 25, 13, 3698 },
    { 24, 14, 7399 },
    { 26, 15, 14797 },
    { 49, 19, 236736 },
    { 50, 19, 236737 },
    { 51, 19, 236738 },
    { 52, 19, 236739 },
    { 53, 19, 236740 },
    { 27, 20, 473482 },
    { 28, 20, 473483 },
    { 29, 20, 473484 },
    { 30, 20, 473485 },
    { 31, 20, 473486 },
    { 32, 20, 473487 },
    { 33, 20, 473488 },
    { 34, 20, 473489 },
    { 35, 20, 473490 },
    { 36, 20, 473491 },
    { 37, 20, 473492 },
    { 38, 20, 473493 },
    { 39, 20, 473494 },
    { 40, 20, 473495 },
    { 41, 20, 473496 },
    { 42, 20, 473497 },
    { 43, 20, 473498 },
    { 44, 20, 473499 },
    { 45, 20, 473500 },
    { 46, 20, 473501 },
    { 47, 20, 473502 },
    { 48, 20, 473503 },
    { 99, 21,  0 } /* Shouldn't come this far */
};

static int8_t rvlc_huffman_sf(bitfile *ld_sf, bitfile *ld_esc /*,
                              int8_t direction*/)
{
    uint16_t i, j;
    int16_t index;
    uint32_t cw;
    rvlc_huff_table *h = book_rvlc;
    int8_t direction = +1;

    i = h->len;
    if (direction > 0)
        cw = faad_getbits(ld_sf, i DEBUGVAR(1,0,""));
    else
        cw = 0 /* faad_getbits_rev(ld_sf, i DEBUGVAR(1,0,"")) */;

    while ((cw != h->cw)
        && (i < 10))
    {
        h++;
        j = h->len-i;
        i += j;
        cw <<= j;
        if (direction > 0)
            cw |= faad_getbits(ld_sf, j DEBUGVAR(1,0,""));
        else
            cw |= 0 /* faad_getbits_rev(ld_sf, j DEBUGVAR(1,0,"")) */;
    }

    index = h->index;

    if (index == +ESC_VAL)
    {
        int8_t esc = rvlc_huffman_esc(ld_esc /*, direction*/);
        if (esc == 99)
            return 99;
        index += esc;
#ifdef PRINT_RVLC
        printf("esc: %d - ", esc);
#endif
    }
    if (index == -ESC_VAL)
    {
        int8_t esc = rvlc_huffman_esc(ld_esc /*, direction*/);
        if (esc == 99)
            return 99;
        index -= esc;
#ifdef PRINT_RVLC
        printf("esc: %d - ", esc);
#endif
    }

    return (int8_t)index;
}

static int8_t rvlc_huffman_esc(bitfile *ld /*,
                               int8_t direction*/)
{
    uint16_t i, j;
    uint32_t cw;
    rvlc_huff_table *h = book_escape;
    int8_t direction = +1;

    i = h->len;
    if (direction > 0)
        cw = faad_getbits(ld, i DEBUGVAR(1,0,""));
    else
        cw = 0 /* faad_getbits_rev(ld, i DEBUGVAR(1,0,"")) */;

    while ((cw != h->cw)
        && (i < 21))
    {
        h++;
        j = h->len-i;
        i += j;
        cw <<= j;
        if (direction > 0)
            cw |= faad_getbits(ld, j DEBUGVAR(1,0,""));
        else
            cw |= 0 /* faad_getbits_rev(ld, j DEBUGVAR(1,0,"")) */;
    }

    return (int8_t)h->index;
}

#endif


Coverage Report

Created: 2026-07-16 06:20

Line	Count	Source
1		/*
2		** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding
3		** Copyright (C) 2003-2005 M. Bakker, Nero AG, http://www.nero.com
4		**
5		** This program is free software; you can redistribute it and/or modify
6		** it under the terms of the GNU General Public License as published by
7		** the Free Software Foundation; either version 2 of the License, or
8		** (at your option) any later version.
9		**
10		** This program is distributed in the hope that it will be useful,
11		** but WITHOUT ANY WARRANTY; without even the implied warranty of
12		** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13		** GNU General Public License for more details.
14		**
15		** You should have received a copy of the GNU General Public License
16		** along with this program; if not, write to the Free Software
17		** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
18		**
19		** Any non-GPL usage of this software or parts of this software is strictly
20		** forbidden.
21		**
22		** The "appropriate copyright message" mentioned in section 2c of the GPLv2
23		** must read: "Code from FAAD2 is copyright (c) Nero AG, www.nero.com"
24		**
25		** Commercial non-GPL licensing of this software is possible.
26		** For more info contact Nero AG through Mpeg4AAClicense@nero.com.
27		**
28		** $Id: rvlc.c,v 1.21 2007/11/01 12:33:34 menno Exp $
29		**/
30
31		/* RVLC scalefactor decoding
32		*
33		* RVLC works like this:
34		* 1. Only symmetric huffman codewords are used
35		* 2. Total length of the scalefactor data is stored in the bitsream
36		* 3. Scalefactors are DPCM coded
37		* 4. Next to the starting value for DPCM the ending value is also stored
38		*
39		* With all this it is possible to read the scalefactor data from 2 sides.
40		* If there is a bit error in the scalefactor data it is possible to start
41		* decoding from the other end of the data, to find all but 1 scalefactor.
42		*/
43
44		#include "common.h"
45		#include "structs.h"
46
47		#include <stdlib.h>
48
49		#include "syntax.h"
50		#include "bits.h"
51		#include "rvlc.h"
52
53
54		#ifdef ERROR_RESILIENCE
55
56		//#define PRINT_RVLC
57
58		/* static function declarations */
59		static uint8_t rvlc_decode_sf_forward(ic_stream *ics,
60		bitfile *ld_sf,
61		bitfile *ld_esc,
62		uint8_t *is_used);
63		#if 0
64		static uint8_t rvlc_decode_sf_reverse(ic_stream *ics,
65		bitfile *ld_sf,
66		bitfile *ld_esc,
67		uint8_t is_used);
68		#endif
69		static int8_t rvlc_huffman_sf(bitfile ld_sf, bitfile ld_esc /*,
70		int8_t direction*/);
71		static int8_t rvlc_huffman_esc(bitfile ld_esc /, int8_t direction*/);
72
73
74		uint8_t rvlc_scale_factor_data(ic_stream ics, bitfile ld)
75	9.58k	{
76	9.58k	uint8_t bits = 9;
77
78	9.58k	ics->sf_concealment = faad_get1bit(ld
79	9.58k	DEBUGVAR(1,149,"rvlc_scale_factor_data(): sf_concealment"));
80	9.58k	ics->rev_global_gain = (uint8_t)faad_getbits(ld, 8
81	9.58k	DEBUGVAR(1,150,"rvlc_scale_factor_data(): rev_global_gain"));
82
83	9.58k	if (ics->window_sequence == EIGHT_SHORT_SEQUENCE)
84	435	bits = 11;
85
86		/* the number of bits used for the huffman codewords */
87	9.58k	ics->length_of_rvlc_sf = (uint16_t)faad_getbits(ld, bits
88	9.58k	DEBUGVAR(1,151,"rvlc_scale_factor_data(): length_of_rvlc_sf"));
89
90	9.58k	if (ics->noise_used)
91	385	{
92	385	ics->dpcm_noise_nrg = (uint16_t)faad_getbits(ld, 9
93	385	DEBUGVAR(1,152,"rvlc_scale_factor_data(): dpcm_noise_nrg"));
94
95		/* the 9 bits of dpcm_noise_nrg are counted in length_of_rvlc_sf, so a
96		conformant value is at least 9; reject a smaller one before the
97		unsigned subtraction wraps length_of_rvlc_sf to a huge value */
98	385	if (ics->length_of_rvlc_sf < 9)
99	12	return 8;
100
101	373	ics->length_of_rvlc_sf -= 9;
102	373	}
103
104	9.56k	ics->sf_escapes_present = faad_get1bit(ld
105	9.56k	DEBUGVAR(1,153,"rvlc_scale_factor_data(): sf_escapes_present"));
106
107	9.56k	if (ics->sf_escapes_present)
108	1.18k	{
109	1.18k	ics->length_of_rvlc_escapes = (uint8_t)faad_getbits(ld, 8
110	1.18k	DEBUGVAR(1,154,"rvlc_scale_factor_data(): length_of_rvlc_escapes"));
111	1.18k	}
112
113	9.56k	if (ics->noise_used)
114	373	{
115	373	ics->dpcm_noise_last_position = (uint16_t)faad_getbits(ld, 9
116	373	DEBUGVAR(1,155,"rvlc_scale_factor_data(): dpcm_noise_last_position"));
117	373	}
118
119	9.56k	return 0;
120	9.58k	}
121
122		uint8_t rvlc_decode_scale_factors(ic_stream ics, bitfile ld)
123	9.56k	{
124	9.56k	uint8_t result;
125	9.56k	uint8_t intensity_used = 0;
126	9.56k	uint8_t *rvlc_sf_buffer = NULL;
127	9.56k	uint8_t *rvlc_esc_buffer = NULL;
128	9.56k	bitfile ld_rvlc_sf = {0}, ld_rvlc_esc = {0};
129		// bitfile ld_rvlc_sf_rev, ld_rvlc_esc_rev;
130
131	9.56k	if (ics->length_of_rvlc_sf > 0)
132	2.67k	{
133		/* We read length_of_rvlc_sf bits here to put it in a
134		seperate bitfile.
135		*/
136	2.67k	rvlc_sf_buffer = faad_getbitbuffer(ld, ics->length_of_rvlc_sf
137	2.67k	DEBUGVAR(1,156,"rvlc_decode_scale_factors(): bitbuffer: length_of_rvlc_sf"));
138
139	2.67k	faad_initbits(&ld_rvlc_sf, (void*)rvlc_sf_buffer, bit2byte(ics->length_of_rvlc_sf));
140		// faad_initbits_rev(&ld_rvlc_sf_rev, (void*)rvlc_sf_buffer,
141		// ics->length_of_rvlc_sf);
142	2.67k	}
143	9.56k	if ((ics->length_of_rvlc_sf == 0) \|\| (ld_rvlc_sf.error != 0)) {
144	6.88k	memset(&ld_rvlc_sf, 0, sizeof(ld_rvlc_sf));
145	6.88k	ld_rvlc_sf.error = 1;
146	6.88k	}
147
148	9.56k	if (ics->sf_escapes_present)
149	1.18k	{
150		/* We read length_of_rvlc_escapes bits here to put it in a
151		seperate bitfile.
152		*/
153	1.18k	rvlc_esc_buffer = faad_getbitbuffer(ld, ics->length_of_rvlc_escapes
154	1.18k	DEBUGVAR(1,157,"rvlc_decode_scale_factors(): bitbuffer: length_of_rvlc_escapes"));
155
156	1.18k	faad_initbits(&ld_rvlc_esc, (void*)rvlc_esc_buffer, bit2byte(ics->length_of_rvlc_escapes));
157		// faad_initbits_rev(&ld_rvlc_esc_rev, (void*)rvlc_esc_buffer,
158		// ics->length_of_rvlc_escapes);
159	1.18k	}
160	9.56k	if (!ics->sf_escapes_present \|\| (ld_rvlc_esc.error != 0)) {
161	8.75k	memset(&ld_rvlc_esc, 0, sizeof(ld_rvlc_esc));
162	8.75k	ld_rvlc_esc.error = 1;
163	8.75k	}
164
165		/* decode the rvlc scale factors and escapes */
166	9.56k	result = rvlc_decode_sf_forward(ics, &ld_rvlc_sf,
167	9.56k	&ld_rvlc_esc, &intensity_used);
168		// result = rvlc_decode_sf_reverse(ics, &ld_rvlc_sf_rev,
169		// &ld_rvlc_esc_rev, intensity_used);
170
171
172	9.56k	if (rvlc_esc_buffer) faad_free(rvlc_esc_buffer);
173	9.56k	if (rvlc_sf_buffer) faad_free(rvlc_sf_buffer);
174
175	9.56k	if (ics->length_of_rvlc_sf > 0)
176	2.67k	faad_endbits(&ld_rvlc_sf);
177	9.56k	if (ics->sf_escapes_present)
178	1.18k	faad_endbits(&ld_rvlc_esc);
179
180	9.56k	return result;
181	9.56k	}
182
183		static uint8_t rvlc_decode_sf_forward(ic_stream ics, bitfile ld_sf, bitfile *ld_esc,
184		uint8_t *intensity_used)
185	9.56k	{
186	9.56k	int8_t g, sfb;
187	9.56k	int8_t t = 0;
188	9.56k	int8_t error = ld_sf->error \| ld_esc->error;
189	9.56k	int8_t noise_pcm_flag = 1;
190
191	9.56k	int16_t scale_factor = ics->global_gain;
192	9.56k	int16_t is_position = 0;
193	9.56k	int16_t noise_energy = ics->global_gain - 90 - 256;
194	9.56k	int16_t scale_factor_max = 255;
195	9.56k	#ifdef FIXED_POINT
196		/* TODO: consider rolling out to regular build. */
197	9.56k	#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
198		/* The value is inexact, adjusted to current fuzzer findings. */
199	9.56k	scale_factor_max = 165;
200	9.56k	#endif // FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
201	9.56k	#endif // FIXED_POINT
202
203		#ifdef PRINT_RVLC
204		printf("\nglobal_gain: %d\n", ics->global_gain);
205		#endif
206
207	21.6k	for (g = 0; g < ics->num_window_groups; g++)
208	12.0k	{
209	41.1k	for (sfb = 0; sfb < ics->max_sfb; sfb++)
210	29.1k	{
211	29.1k	if (error)
212	18.7k	{
213	18.7k	ics->scale_factors[g][sfb] = 0;
214	18.7k	} else {
215	10.4k	switch (ics->sfb_cb[g][sfb])
216	10.4k	{
217	923	case ZERO_HCB: /* zero book */
218	923	ics->scale_factors[g][sfb] = 0;
219	923	break;
220	434	case INTENSITY_HCB: /* intensity books */
221	673	case INTENSITY_HCB2:
222
223	673	*intensity_used = 1;
224
225		/* decode intensity position */
226	673	t = rvlc_huffman_sf(ld_sf, ld_esc /, +1/);
227
228	673	is_position += t;
229	673	ics->scale_factors[g][sfb] = is_position;
230
231	673	break;
232	5.93k	case NOISE_HCB: /* noise books */
233
234		/* decode noise energy */
235	5.93k	if (noise_pcm_flag)
236	340	{
237	340	int16_t n = ics->dpcm_noise_nrg;
238	340	noise_pcm_flag = 0;
239	340	noise_energy += n;
240	5.59k	} else {
241	5.59k	t = rvlc_huffman_sf(ld_sf, ld_esc /, +1/);
242	5.59k	noise_energy += t;
243	5.59k	}
244
245	5.93k	ics->scale_factors[g][sfb] = noise_energy;
246
247	5.93k	break;
248	2.91k	default: /* spectral books */
249
250		/* decode scale factor */
251	2.91k	t = rvlc_huffman_sf(ld_sf, ld_esc /, +1/);
252
253	2.91k	scale_factor += t;
254	2.91k	if (scale_factor < 0 \|\| scale_factor > 255)
255	29	return 4;
256
257	2.88k	ics->scale_factors[g][sfb] = min(scale_factor, scale_factor_max);
258
259	2.88k	break;
260	10.4k	}
261		#ifdef PRINT_RVLC
262		printf("%3d:%4d%4d\n", sfb, ics->sfb_cb[g][sfb],
263		ics->scale_factors[g][sfb]);
264		#endif
265	10.4k	if (t == 99)
266	305	{
267	305	error = 1;
268	305	}
269	10.4k	}
270	29.1k	}
271	12.0k	}
272		#ifdef PRINT_RVLC
273		printf("\n\n");
274		#endif
275
276	9.53k	return 0;
277	9.56k	}
278
279		#if 0 // not used right now, doesn't work correctly yet
280		static uint8_t rvlc_decode_sf_reverse(ic_stream ics, bitfile ld_sf, bitfile *ld_esc,
281		uint8_t intensity_used)
282		{
283		int8_t g, sfb;
284		int8_t t = 0;
285		int8_t error = 0;
286		int8_t noise_pcm_flag = 1, is_pcm_flag = 1, sf_pcm_flag = 1;
287
288		int16_t scale_factor = ics->rev_global_gain;
289		int16_t is_position = 0;
290		int16_t noise_energy = ics->rev_global_gain;
291
292		#ifdef PRINT_RVLC
293		printf("\nrev_global_gain: %d\n", ics->rev_global_gain);
294		#endif
295
296		if (intensity_used)
297		{
298		is_position = rvlc_huffman_sf(ld_sf, ld_esc, -1);
299		#ifdef PRINT_RVLC
300		printf("is_position: %d\n", is_position);
301		#endif
302		}
303
304		for (g = ics->num_window_groups-1; g >= 0; g--)
305		{
306		for (sfb = ics->max_sfb-1; sfb >= 0; sfb--)
307		{
308		if (error)
309		{
310		ics->scale_factors[g][sfb] = 0;
311		} else {
312		switch (ics->sfb_cb[g][sfb])
313		{
314		case ZERO_HCB: /* zero book */
315		ics->scale_factors[g][sfb] = 0;
316		break;
317		case INTENSITY_HCB: /* intensity books */
318		case INTENSITY_HCB2:
319
320		if (is_pcm_flag)
321		{
322		is_pcm_flag = 0;
323		ics->scale_factors[g][sfb] = is_position;
324		} else {
325		t = rvlc_huffman_sf(ld_sf, ld_esc, -1);
326		is_position -= t;
327
328		ics->scale_factors[g][sfb] = (uint8_t)is_position;
329		}
330		break;
331		case NOISE_HCB: /* noise books */
332
333		/* decode noise energy */
334		if (noise_pcm_flag)
335		{
336		noise_pcm_flag = 0;
337		noise_energy = ics->dpcm_noise_last_position;
338		} else {
339		t = rvlc_huffman_sf(ld_sf, ld_esc, -1);
340		noise_energy -= t;
341		}
342
343		ics->scale_factors[g][sfb] = (uint8_t)noise_energy;
344		break;
345		default: /* spectral books */
346
347		if (sf_pcm_flag \|\| (sfb == 0))
348		{
349		sf_pcm_flag = 0;
350		if (sfb == 0)
351		scale_factor = ics->global_gain;
352		} else {
353		/* decode scale factor */
354		t = rvlc_huffman_sf(ld_sf, ld_esc, -1);
355		scale_factor -= t;
356		}
357
358		if (scale_factor < 0)
359		return 4;
360
361		ics->scale_factors[g][sfb] = (uint8_t)scale_factor;
362		break;
363		}
364		#ifdef PRINT_RVLC
365		printf("%3d:%4d%4d\n", sfb, ics->sfb_cb[g][sfb],
366		ics->scale_factors[g][sfb]);
367		#endif
368		if (t == 99)
369		{
370		error = 1;
371		}
372		}
373		}
374		}
375
376		#ifdef PRINT_RVLC
377		printf("\n\n");
378		#endif
379
380		return 0;
381		}
382		#endif
383
384		/* index == 99 means not allowed codeword */
385		static rvlc_huff_table book_rvlc[] = {
386		/index length codeword /
387		{ 0, 1, 0 }, /* 0 */
388		{ -1, 3, 5 }, /* 101 */
389		{ 1, 3, 7 }, /* 111 */
390		{ -2, 4, 9 }, /* 1001 */
391		{ -3, 5, 17 }, /* 10001 */
392		{ 2, 5, 27 }, /* 11011 */
393		{ -4, 6, 33 }, /* 100001 */
394		{ 99, 6, 50 }, /* 110010 */
395		{ 3, 6, 51 }, /* 110011 */
396		{ 99, 6, 52 }, /* 110100 */
397		{ -7, 7, 65 }, /* 1000001 */
398		{ 99, 7, 96 }, /* 1100000 */
399		{ 99, 7, 98 }, /* 1100010 */
400		{ 7, 7, 99 }, /* 1100011 */
401		{ 4, 7, 107 }, /* 1101011 */
402		{ -5, 8, 129 }, /* 10000001 */
403		{ 99, 8, 194 }, /* 11000010 */
404		{ 5, 8, 195 }, /* 11000011 */
405		{ 99, 8, 212 }, /* 11010100 */
406		{ 99, 9, 256 }, /* 100000000 */
407		{ -6, 9, 257 }, /* 100000001 */
408		{ 99, 9, 426 }, /* 110101010 */
409		{ 6, 9, 427 }, /* 110101011 */
410		{ 99, 10, 0 } /* Shouldn't come this far */
411		};
412
413		static rvlc_huff_table book_escape[] = {
414		/index length codeword /
415		{ 1, 2, 0 },
416		{ 0, 2, 2 },
417		{ 3, 3, 2 },
418		{ 2, 3, 6 },
419		{ 4, 4, 14 },
420		{ 7, 5, 13 },
421		{ 6, 5, 15 },
422		{ 5, 5, 31 },
423		{ 11, 6, 24 },
424		{ 10, 6, 25 },
425		{ 9, 6, 29 },
426		{ 8, 6, 61 },
427		{ 13, 7, 56 },
428		{ 12, 7, 120 },
429		{ 15, 8, 114 },
430		{ 14, 8, 242 },
431		{ 17, 9, 230 },
432		{ 16, 9, 486 },
433		{ 19, 10, 463 },
434		{ 18, 10, 974 },
435		{ 22, 11, 925 },
436		{ 20, 11, 1950 },
437		{ 21, 11, 1951 },
438		{ 23, 12, 1848 },
439		{ 25, 13, 3698 },
440		{ 24, 14, 7399 },
441		{ 26, 15, 14797 },
442		{ 49, 19, 236736 },
443		{ 50, 19, 236737 },
444		{ 51, 19, 236738 },
445		{ 52, 19, 236739 },
446		{ 53, 19, 236740 },
447		{ 27, 20, 473482 },
448		{ 28, 20, 473483 },
449		{ 29, 20, 473484 },
450		{ 30, 20, 473485 },
451		{ 31, 20, 473486 },
452		{ 32, 20, 473487 },
453		{ 33, 20, 473488 },
454		{ 34, 20, 473489 },
455		{ 35, 20, 473490 },
456		{ 36, 20, 473491 },
457		{ 37, 20, 473492 },
458		{ 38, 20, 473493 },
459		{ 39, 20, 473494 },
460		{ 40, 20, 473495 },
461		{ 41, 20, 473496 },
462		{ 42, 20, 473497 },
463		{ 43, 20, 473498 },
464		{ 44, 20, 473499 },
465		{ 45, 20, 473500 },
466		{ 46, 20, 473501 },
467		{ 47, 20, 473502 },
468		{ 48, 20, 473503 },
469		{ 99, 21, 0 } /* Shouldn't come this far */
470		};
471
472		static int8_t rvlc_huffman_sf(bitfile ld_sf, bitfile ld_esc /*,
473		int8_t direction*/)
474	9.18k	{
475	9.18k	uint16_t i, j;
476	9.18k	int16_t index;
477	9.18k	uint32_t cw;
478	9.18k	rvlc_huff_table *h = book_rvlc;
479	9.18k	int8_t direction = +1;
480
481	9.18k	i = h->len;
482	9.18k	if (direction > 0)
483	9.18k	cw = faad_getbits(ld_sf, i DEBUGVAR(1,0,""));
484	0	else
485	0	cw = 0 /* faad_getbits_rev(ld_sf, i DEBUGVAR(1,0,"")) */;
486
487	29.7k	while ((cw != h->cw)
488	20.5k	&& (i < 10))
489	20.5k	{
490	20.5k	h++;
491	20.5k	j = h->len-i;
492	20.5k	i += j;
493	20.5k	cw <<= j;
494	20.5k	if (direction > 0)
495	20.5k	cw \|= faad_getbits(ld_sf, j DEBUGVAR(1,0,""));
496	0	else
497	0	cw \|= 0 /* faad_getbits_rev(ld_sf, j DEBUGVAR(1,0,"")) */;
498	20.5k	}
499
500	9.18k	index = h->index;
501
502	9.18k	if (index == +ESC_VAL)
503	458	{
504	458	int8_t esc = rvlc_huffman_esc(ld_esc /, direction/);
505	458	if (esc == 99)
506	0	return 99;
507	458	index += esc;
508		#ifdef PRINT_RVLC
509		printf("esc: %d - ", esc);
510		#endif
511	458	}
512	9.18k	if (index == -ESC_VAL)
513	338	{
514	338	int8_t esc = rvlc_huffman_esc(ld_esc /, direction/);
515	338	if (esc == 99)
516	0	return 99;
517	338	index -= esc;
518		#ifdef PRINT_RVLC
519		printf("esc: %d - ", esc);
520		#endif
521	338	}
522
523	9.18k	return (int8_t)index;
524	9.18k	}
525
526		static int8_t rvlc_huffman_esc(bitfile ld /,
527		int8_t direction*/)
528	796	{
529	796	uint16_t i, j;
530	796	uint32_t cw;
531	796	rvlc_huff_table *h = book_escape;
532	796	int8_t direction = +1;
533
534	796	i = h->len;
535	796	if (direction > 0)
536	796	cw = faad_getbits(ld, i DEBUGVAR(1,0,""));
537	0	else
538	0	cw = 0 /* faad_getbits_rev(ld, i DEBUGVAR(1,0,"")) */;
539
540	5.51k	while ((cw != h->cw)
541	4.71k	&& (i < 21))
542	4.71k	{
543	4.71k	h++;
544	4.71k	j = h->len-i;
545	4.71k	i += j;
546	4.71k	cw <<= j;
547	4.71k	if (direction > 0)
548	4.71k	cw \|= faad_getbits(ld, j DEBUGVAR(1,0,""));
549	0	else
550	0	cw \|= 0 /* faad_getbits_rev(ld, j DEBUGVAR(1,0,"")) */;
551	4.71k	}
552
553	796	return (int8_t)h->index;
554	796	}
555
556		#endif
557