/*

** 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: sbr_syntax.c,v 1.39 2009/01/26 22:32:31 menno Exp $

**/

#include "common.h"

#include "structs.h"

#ifdef SBR_DEC

#include "sbr_syntax.h"

#include "syntax.h"

#include "sbr_huff.h"

#include "sbr_fbt.h"

#include "sbr_tf_grid.h"

#include "sbr_e_nf.h"

#include "bits.h"

#ifdef PS_DEC

#include "ps_dec.h"

#endif

#ifdef DRM_PS

#include "drm_dec.h"

#endif

#include "analysis.h"

/* static function declarations */

/* static function declarations */

static void sbr_header(bitfile *ld, sbr_info *sbr);

static uint8_t calc_sbr_tables(sbr_info *sbr, uint8_t start_freq, uint8_t stop_freq,

                               uint8_t samplerate_mode, uint8_t freq_scale,

                               uint8_t alter_scale, uint8_t xover_band);

static uint8_t sbr_data(bitfile *ld, sbr_info *sbr);

static uint16_t sbr_extension(bitfile *ld, sbr_info *sbr,

                              uint8_t bs_extension_id, uint16_t num_bits_left);

static uint8_t sbr_single_channel_element(bitfile *ld, sbr_info *sbr);

static uint8_t sbr_channel_pair_element(bitfile *ld, sbr_info *sbr);

static uint8_t sbr_grid(bitfile *ld, sbr_info *sbr, uint8_t ch);

static void sbr_dtdf(bitfile *ld, sbr_info *sbr, uint8_t ch);

static void invf_mode(bitfile *ld, sbr_info *sbr, uint8_t ch);

static void sinusoidal_coding(bitfile *ld, sbr_info *sbr, uint8_t ch);

static void sbr_reset(sbr_info *sbr)

{

#if 0

    printf("%d\n", sbr->bs_start_freq_prev);

    printf("%d\n", sbr->bs_stop_freq_prev);

    printf("%d\n", sbr->bs_freq_scale_prev);

    printf("%d\n", sbr->bs_alter_scale_prev);

    printf("%d\n", sbr->bs_xover_band_prev);

    printf("%d\n\n", sbr->bs_noise_bands_prev);

#endif

    /* if these are different from the previous frame: Reset = 1 */

    if ((sbr->bs_start_freq != sbr->bs_start_freq_prev) ||

        (sbr->bs_stop_freq != sbr->bs_stop_freq_prev) ||

        (sbr->bs_freq_scale != sbr->bs_freq_scale_prev) ||

        (sbr->bs_alter_scale != sbr->bs_alter_scale_prev) ||

        (sbr->bs_xover_band != sbr->bs_xover_band_prev) ||

        (sbr->bs_noise_bands != sbr->bs_noise_bands_prev))

    {

        sbr->Reset = 1;

    } else {

        sbr->Reset = 0;

    }

    sbr->bs_start_freq_prev = sbr->bs_start_freq;

    sbr->bs_stop_freq_prev = sbr->bs_stop_freq;

    sbr->bs_freq_scale_prev = sbr->bs_freq_scale;

    sbr->bs_alter_scale_prev = sbr->bs_alter_scale;

    sbr->bs_xover_band_prev = sbr->bs_xover_band;

    sbr->bs_noise_bands_prev = sbr->bs_noise_bands;

}

static uint8_t calc_sbr_tables(sbr_info *sbr, uint8_t start_freq, uint8_t stop_freq,

                               uint8_t samplerate_mode, uint8_t freq_scale,

                               uint8_t alter_scale, uint8_t xover_band)

{

    uint8_t result = 0;

    uint8_t k2;

    /* calculate the Master Frequency Table */

    sbr->k0 = qmf_start_channel(start_freq, samplerate_mode, sbr->sample_rate);

    k2 = qmf_stop_channel(stop_freq, sbr->sample_rate, sbr->k0);

    /* check k0 and k2 */

    if (sbr->sample_rate >= 48000)

    {

        if ((k2 - sbr->k0) > 32)

            result += 1;

    } else if (sbr->sample_rate <= 32000) {

        if ((k2 - sbr->k0) > 48)

            result += 1;

    } else { /* (sbr->sample_rate == 44100) */

        if ((k2 - sbr->k0) > 45)

            result += 1;

    }

    if (freq_scale == 0)

    {

        result += master_frequency_table_fs0(sbr, sbr->k0, k2, alter_scale);

    } else {

        result += master_frequency_table(sbr, sbr->k0, k2, freq_scale, alter_scale);

    }

    result += derived_frequency_table(sbr, xover_band, k2);

    result = (result > 0) ? 1 : 0;

    return result;

}

/* table 2 */

uint8_t sbr_extension_data(bitfile *ld, sbr_info *sbr, uint16_t cnt,

                           uint8_t psResetFlag)

{

    uint8_t result = 0;

    uint16_t num_align_bits = 0;

    uint16_t num_sbr_bits1 = (uint16_t)faad_get_processed_bits(ld);

    uint16_t num_sbr_bits2;

    uint8_t saved_start_freq, saved_samplerate_mode;

    uint8_t saved_stop_freq, saved_freq_scale;

    uint8_t saved_alter_scale, saved_xover_band;

#if (defined(PS_DEC) || defined(DRM_PS))

    if (psResetFlag)

        sbr->psResetFlag = psResetFlag;

#endif

#ifdef DRM

    if (!sbr->Is_DRM_SBR)

#endif

    {

        uint8_t bs_extension_type = (uint8_t)faad_getbits(ld, 4

            DEBUGVAR(1,198,"sbr_bitstream(): bs_extension_type"));

        if (bs_extension_type == EXT_SBR_DATA_CRC)

        {

            sbr->bs_sbr_crc_bits = (uint16_t)faad_getbits(ld, 10

                DEBUGVAR(1,199,"sbr_bitstream(): bs_sbr_crc_bits"));

        }

    }

    /* save old header values, in case the new ones are corrupted */

    saved_start_freq = sbr->bs_start_freq;

    saved_samplerate_mode = sbr->bs_samplerate_mode;

    saved_stop_freq = sbr->bs_stop_freq;

    saved_freq_scale = sbr->bs_freq_scale;

    saved_alter_scale = sbr->bs_alter_scale;

    saved_xover_band = sbr->bs_xover_band;

    sbr->bs_header_flag = faad_get1bit(ld

        DEBUGVAR(1,200,"sbr_bitstream(): bs_header_flag"));

    if (sbr->bs_header_flag)

        sbr_header(ld, sbr);

    /* Reset? */

    sbr_reset(sbr);

    /* first frame should have a header */

    //if (!(sbr->frame == 0 && sbr->bs_header_flag == 0))

    if (sbr->header_count != 0)

    {

        if (sbr->Reset || (sbr->bs_header_flag && sbr->just_seeked))

        {

            uint8_t rt = calc_sbr_tables(sbr, sbr->bs_start_freq, sbr->bs_stop_freq,

                sbr->bs_samplerate_mode, sbr->bs_freq_scale,

                sbr->bs_alter_scale, sbr->bs_xover_band);

            /* if an error occured with the new header values revert to the old ones */

            if (rt > 0)

            {

                result += calc_sbr_tables(sbr, saved_start_freq, saved_stop_freq,

                    saved_samplerate_mode, saved_freq_scale,

                    saved_alter_scale, saved_xover_band);

            }

        }

        if (result == 0)

        {

            result = sbr_data(ld, sbr);

            /* sbr_data() returning an error means that there was an error in

               envelope_time_border_vector().

               In this case the old time border vector is saved and all the previous

               data normally read after sbr_grid() is saved.

            */

            /* to be on the safe side, calculate old sbr tables in case of error */

            if ((result > 0) &&

                (sbr->Reset || (sbr->bs_header_flag && sbr->just_seeked)))

            {

                result += calc_sbr_tables(sbr, saved_start_freq, saved_stop_freq,

                    saved_samplerate_mode, saved_freq_scale,

                    saved_alter_scale, saved_xover_band);

            }

            /* we should be able to safely set result to 0 now, */

            /* but practise indicates this doesn't work well */

        }

    } else {

        result = 1;

    }

    num_sbr_bits2 = (uint16_t)faad_get_processed_bits(ld) - num_sbr_bits1;

    /* check if we read more bits then were available for sbr */

    if (8*cnt < num_sbr_bits2)

    {

        faad_resetbits(ld, num_sbr_bits1 + 8u * cnt);

        num_sbr_bits2 = 8*cnt;

#ifdef PS_DEC

        /* turn off PS for the unfortunate case that we randomly read some

         * PS data that looks correct */

        sbr->ps_used = 0;

#endif

        /* Make sure it doesn't decode SBR in this frame, or we'll get glitches */

        return 1;

    }

#ifdef DRM

    if (!sbr->Is_DRM_SBR)

#endif

    {

        /* -4 does not apply, bs_extension_type is re-read in this function */

        num_align_bits = 8*cnt /*- 4*/ - num_sbr_bits2;

        while (num_align_bits > 7)

        {

            faad_getbits(ld, 8

                DEBUGVAR(1,999,"sbr_bitstream(): num_align_bits"));

            num_align_bits -= 8;

        }

        faad_getbits(ld, num_align_bits

            DEBUGVAR(1,999,"sbr_bitstream(): num_align_bits"));

    }

    return result;

}

/* table 3 */

static void sbr_header(bitfile *ld, sbr_info *sbr)

{

    uint8_t bs_header_extra_1, bs_header_extra_2;

    sbr->header_count++;

    sbr->bs_amp_res = faad_get1bit(ld

        DEBUGVAR(1,203,"sbr_header(): bs_amp_res"));

    /* bs_start_freq and bs_stop_freq must define a fequency band that does

       not exceed 48 channels */

    sbr->bs_start_freq = (uint8_t)faad_getbits(ld, 4

        DEBUGVAR(1,204,"sbr_header(): bs_start_freq"));

    sbr->bs_stop_freq = (uint8_t)faad_getbits(ld, 4

        DEBUGVAR(1,205,"sbr_header(): bs_stop_freq"));

    sbr->bs_xover_band = (uint8_t)faad_getbits(ld, 3

        DEBUGVAR(1,206,"sbr_header(): bs_xover_band"));

    faad_getbits(ld, 2

        DEBUGVAR(1,207,"sbr_header(): bs_reserved_bits_hdr"));

    bs_header_extra_1 = (uint8_t)faad_get1bit(ld

        DEBUGVAR(1,208,"sbr_header(): bs_header_extra_1"));

    bs_header_extra_2 = (uint8_t)faad_get1bit(ld

        DEBUGVAR(1,209,"sbr_header(): bs_header_extra_2"));

    if (bs_header_extra_1)

    {

        sbr->bs_freq_scale = (uint8_t)faad_getbits(ld, 2

            DEBUGVAR(1,211,"sbr_header(): bs_freq_scale"));

        sbr->bs_alter_scale = (uint8_t)faad_get1bit(ld

            DEBUGVAR(1,212,"sbr_header(): bs_alter_scale"));

        sbr->bs_noise_bands = (uint8_t)faad_getbits(ld, 2

            DEBUGVAR(1,213,"sbr_header(): bs_noise_bands"));

    } else {

        /* Default values */

        sbr->bs_freq_scale = 2;

        sbr->bs_alter_scale = 1;

        sbr->bs_noise_bands = 2;

    }

    if (bs_header_extra_2)

    {

        sbr->bs_limiter_bands = (uint8_t)faad_getbits(ld, 2

            DEBUGVAR(1,214,"sbr_header(): bs_limiter_bands"));

        sbr->bs_limiter_gains = (uint8_t)faad_getbits(ld, 2

            DEBUGVAR(1,215,"sbr_header(): bs_limiter_gains"));

        sbr->bs_interpol_freq = (uint8_t)faad_get1bit(ld

            DEBUGVAR(1,216,"sbr_header(): bs_interpol_freq"));

        sbr->bs_smoothing_mode = (uint8_t)faad_get1bit(ld

            DEBUGVAR(1,217,"sbr_header(): bs_smoothing_mode"));

    } else {

        /* Default values */

        sbr->bs_limiter_bands = 2;

        sbr->bs_limiter_gains = 2;

        sbr->bs_interpol_freq = 1;

        sbr->bs_smoothing_mode = 1;

    }

#if 0

    /* print the header to screen */

    printf("bs_amp_res: %d\n", sbr->bs_amp_res);

    printf("bs_start_freq: %d\n", sbr->bs_start_freq);

    printf("bs_stop_freq: %d\n", sbr->bs_stop_freq);

    printf("bs_xover_band: %d\n", sbr->bs_xover_band);

    if (bs_header_extra_1)

    {

        printf("bs_freq_scale: %d\n", sbr->bs_freq_scale);

        printf("bs_alter_scale: %d\n", sbr->bs_alter_scale);

        printf("bs_noise_bands: %d\n", sbr->bs_noise_bands);

    }

    if (bs_header_extra_2)

    {

        printf("bs_limiter_bands: %d\n", sbr->bs_limiter_bands);

        printf("bs_limiter_gains: %d\n", sbr->bs_limiter_gains);

        printf("bs_interpol_freq: %d\n", sbr->bs_interpol_freq);

        printf("bs_smoothing_mode: %d\n", sbr->bs_smoothing_mode);

    }

    printf("\n");

#endif

}

/* table 4 */

static uint8_t sbr_data(bitfile *ld, sbr_info *sbr)

{

    uint8_t result;

#if 0

    sbr->bs_samplerate_mode = faad_get1bit(ld

        DEBUGVAR(1,219,"sbr_data(): bs_samplerate_mode"));

#endif

    sbr->rate = (sbr->bs_samplerate_mode) ? 2 : 1;

    switch (sbr->id_aac)

    {

    case ID_SCE:

    if ((result = sbr_single_channel_element(ld, sbr)) > 0)

      return result;

        break;

    case ID_CPE:

    if ((result = sbr_channel_pair_element(ld, sbr)) > 0)

      return result;

        break;

    }

  return 0;

}

/* table 5 */

static uint8_t sbr_single_channel_element(bitfile *ld, sbr_info *sbr)

{

    uint8_t result;

    if (faad_get1bit(ld

        DEBUGVAR(1,220,"sbr_single_channel_element(): bs_data_extra")))

    {

        faad_getbits(ld, 4

            DEBUGVAR(1,221,"sbr_single_channel_element(): bs_reserved_bits_data"));

    }

#ifdef DRM

    /* bs_coupling, from sbr_channel_pair_base_element(bs_amp_res) */

    if (sbr->Is_DRM_SBR)

    {

        faad_get1bit(ld);

    }

#endif

    if ((result = sbr_grid(ld, sbr, 0)) > 0)

        return result;

    sbr_dtdf(ld, sbr, 0);

    invf_mode(ld, sbr, 0);

    sbr_envelope(ld, sbr, 0);

    sbr_noise(ld, sbr, 0);

#ifndef FIXED_POINT

    envelope_noise_dequantisation(sbr, 0);

#endif

    memset(sbr->bs_add_harmonic[0], 0, 64*sizeof(uint8_t));

    sbr->bs_add_harmonic_flag[0] = faad_get1bit(ld

        DEBUGVAR(1,223,"sbr_single_channel_element(): bs_add_harmonic_flag[0]"));

    if (sbr->bs_add_harmonic_flag[0])

        sinusoidal_coding(ld, sbr, 0);

    sbr->bs_extended_data = faad_get1bit(ld

        DEBUGVAR(1,224,"sbr_single_channel_element(): bs_extended_data[0]"));

    if (sbr->bs_extended_data)

    {

        uint16_t nr_bits_left;

#if (defined(PS_DEC) || defined(DRM_PS))

        uint8_t ps_ext_read = 0;

#endif

        uint16_t cnt = (uint16_t)faad_getbits(ld, 4

            DEBUGVAR(1,225,"sbr_single_channel_element(): bs_extension_size"));

        if (cnt == 15)

        {

            cnt += (uint16_t)faad_getbits(ld, 8

                DEBUGVAR(1,226,"sbr_single_channel_element(): bs_esc_count"));

        }

        nr_bits_left = 8 * cnt;

        while (nr_bits_left > 7)

        {

            uint16_t tmp_nr_bits = 0;

            sbr->bs_extension_id = (uint8_t)faad_getbits(ld, 2

                DEBUGVAR(1,227,"sbr_single_channel_element(): bs_extension_id"));

            tmp_nr_bits += 2;

            /* allow only 1 PS extension element per extension data */

#if (defined(PS_DEC) || defined(DRM_PS))

#if (defined(PS_DEC) && defined(DRM_PS))

            if (sbr->bs_extension_id == EXTENSION_ID_PS || sbr->bs_extension_id == DRM_PARAMETRIC_STEREO)

#else

#ifdef PS_DEC

            if (sbr->bs_extension_id == EXTENSION_ID_PS)

#else

#ifdef DRM_PS

            if (sbr->bs_extension_id == DRM_PARAMETRIC_STEREO)

#endif

#endif

#endif

            {

                if (ps_ext_read == 0)

                {

                    ps_ext_read = 1;

                } else {

                    /* to be safe make it 3, will switch to "default"

                     * in sbr_extension() */

#ifdef DRM

                    return 1;

#else

                    sbr->bs_extension_id = 3;

#endif

                }

            }

#endif

            tmp_nr_bits += sbr_extension(ld, sbr, sbr->bs_extension_id, nr_bits_left);

            /* check if the data read is bigger than the number of available bits */

            if (tmp_nr_bits > nr_bits_left)

                return 1;

            nr_bits_left -= tmp_nr_bits;

        }

        /* Corrigendum */

        if (nr_bits_left > 0)

        {

            faad_getbits(ld, nr_bits_left

                DEBUGVAR(1,280,"sbr_single_channel_element(): nr_bits_left"));

        }

    }

    return 0;

}

/* table 6 */

static uint8_t sbr_channel_pair_element(bitfile *ld, sbr_info *sbr)

{

    uint8_t n, result;

    if (faad_get1bit(ld

        DEBUGVAR(1,228,"sbr_single_channel_element(): bs_data_extra")))

    {

        faad_getbits(ld, 4

            DEBUGVAR(1,228,"sbr_channel_pair_element(): bs_reserved_bits_data"));

        faad_getbits(ld, 4

            DEBUGVAR(1,228,"sbr_channel_pair_element(): bs_reserved_bits_data"));

    }

    sbr->bs_coupling = faad_get1bit(ld

        DEBUGVAR(1,228,"sbr_channel_pair_element(): bs_coupling"));

    if (sbr->bs_coupling)

    {

        if ((result = sbr_grid(ld, sbr, 0)) > 0)

            return result;

        /* need to copy some data from left to right */

        sbr->bs_frame_class[1] = sbr->bs_frame_class[0];

        sbr->L_E[1] = sbr->L_E[0];

        sbr->L_Q[1] = sbr->L_Q[0];

        sbr->bs_pointer[1] = sbr->bs_pointer[0];

        for (n = 0; n <= sbr->L_E[0]; n++)

        {

            sbr->t_E[1][n] = sbr->t_E[0][n];

            sbr->f[1][n] = sbr->f[0][n];

        }

        for (n = 0; n <= sbr->L_Q[0]; n++)

            sbr->t_Q[1][n] = sbr->t_Q[0][n];

        sbr_dtdf(ld, sbr, 0);

        sbr_dtdf(ld, sbr, 1);

        invf_mode(ld, sbr, 0);

        /* more copying */

        for (n = 0; n < sbr->N_Q; n++)

            sbr->bs_invf_mode[1][n] = sbr->bs_invf_mode[0][n];

        sbr_envelope(ld, sbr, 0);

        sbr_noise(ld, sbr, 0);

        sbr_envelope(ld, sbr, 1);

        sbr_noise(ld, sbr, 1);

        memset(sbr->bs_add_harmonic[0], 0, 64*sizeof(uint8_t));

        memset(sbr->bs_add_harmonic[1], 0, 64*sizeof(uint8_t));

        sbr->bs_add_harmonic_flag[0] = faad_get1bit(ld

            DEBUGVAR(1,231,"sbr_channel_pair_element(): bs_add_harmonic_flag[0]"));

        if (sbr->bs_add_harmonic_flag[0])

            sinusoidal_coding(ld, sbr, 0);

        sbr->bs_add_harmonic_flag[1] = faad_get1bit(ld

            DEBUGVAR(1,232,"sbr_channel_pair_element(): bs_add_harmonic_flag[1]"));

        if (sbr->bs_add_harmonic_flag[1])

            sinusoidal_coding(ld, sbr, 1);

    } else {

        uint8_t saved_t_E[6] = {0}, saved_t_Q[3] = {0};

        uint8_t saved_L_E = sbr->L_E[0];

        uint8_t saved_L_Q = sbr->L_Q[0];

        uint8_t saved_frame_class = sbr->bs_frame_class[0];

        for (n = 0; n < saved_L_E; n++)

            saved_t_E[n] = sbr->t_E[0][n];

        for (n = 0; n < saved_L_Q; n++)

            saved_t_Q[n] = sbr->t_Q[0][n];

        if ((result = sbr_grid(ld, sbr, 0)) > 0)

            return result;

        if ((result = sbr_grid(ld, sbr, 1)) > 0)

        {

            /* restore first channel data as well */

            sbr->bs_frame_class[0] = saved_frame_class;

            sbr->L_E[0] = saved_L_E;

            sbr->L_Q[0] = saved_L_Q;

            for (n = 0; n < 6; n++)

                sbr->t_E[0][n] = saved_t_E[n];

            for (n = 0; n < 3; n++)

                sbr->t_Q[0][n] = saved_t_Q[n];

            return result;

        }

        sbr_dtdf(ld, sbr, 0);

        sbr_dtdf(ld, sbr, 1);

        invf_mode(ld, sbr, 0);

        invf_mode(ld, sbr, 1);

        sbr_envelope(ld, sbr, 0);

        sbr_envelope(ld, sbr, 1);

        sbr_noise(ld, sbr, 0);

        sbr_noise(ld, sbr, 1);

        memset(sbr->bs_add_harmonic[0], 0, 64*sizeof(uint8_t));

        memset(sbr->bs_add_harmonic[1], 0, 64*sizeof(uint8_t));

        sbr->bs_add_harmonic_flag[0] = faad_get1bit(ld

            DEBUGVAR(1,239,"sbr_channel_pair_element(): bs_add_harmonic_flag[0]"));

        if (sbr->bs_add_harmonic_flag[0])

            sinusoidal_coding(ld, sbr, 0);

        sbr->bs_add_harmonic_flag[1] = faad_get1bit(ld

            DEBUGVAR(1,240,"sbr_channel_pair_element(): bs_add_harmonic_flag[1]"));

        if (sbr->bs_add_harmonic_flag[1])

            sinusoidal_coding(ld, sbr, 1);

    }

#ifndef FIXED_POINT

    envelope_noise_dequantisation(sbr, 0);

    envelope_noise_dequantisation(sbr, 1);

    if (sbr->bs_coupling)

        unmap_envelope_noise(sbr);

#endif

    sbr->bs_extended_data = faad_get1bit(ld

        DEBUGVAR(1,233,"sbr_channel_pair_element(): bs_extended_data[0]"));

    if (sbr->bs_extended_data)

    {

        uint16_t nr_bits_left;

        uint16_t cnt = (uint16_t)faad_getbits(ld, 4

            DEBUGVAR(1,234,"sbr_channel_pair_element(): bs_extension_size"));

        if (cnt == 15)

        {

            cnt += (uint16_t)faad_getbits(ld, 8

                DEBUGVAR(1,235,"sbr_channel_pair_element(): bs_esc_count"));

        }

        nr_bits_left = 8 * cnt;

        while (nr_bits_left > 7)

        {

            uint16_t tmp_nr_bits = 0;

            sbr->bs_extension_id = (uint8_t)faad_getbits(ld, 2

                DEBUGVAR(1,236,"sbr_channel_pair_element(): bs_extension_id"));

            tmp_nr_bits += 2;

            tmp_nr_bits += sbr_extension(ld, sbr, sbr->bs_extension_id, nr_bits_left);

            /* check if the data read is bigger than the number of available bits */

            if (tmp_nr_bits > nr_bits_left)

                return 1;

            nr_bits_left -= tmp_nr_bits;

        }

        /* Corrigendum */

        if (nr_bits_left > 0)

        {

            faad_getbits(ld, nr_bits_left

                DEBUGVAR(1,280,"sbr_channel_pair_element(): nr_bits_left"));

        }

    }

    return 0;

}

/* integer log[2](x): input range [0,10) */

static uint8_t sbr_log2(const uint8_t val)

{

    uint8_t log2tab[] = { 0, 0, 1, 2, 2, 3, 3, 3, 3, 4 };

    if (val < 10 && val >= 0)

        return log2tab[val];

    else

        return 0;

}

/* table 7 */

static uint8_t sbr_grid(bitfile *ld, sbr_info *sbr, uint8_t ch)

{

    uint8_t i, j, env, rel, result;

    uint8_t bs_abs_bord, bs_abs_bord_1;

    uint8_t bs_num_env = 0;

    uint8_t saved_L_E = sbr->L_E[ch];

    uint8_t saved_L_Q = sbr->L_Q[ch];

    uint8_t saved_frame_class = sbr->bs_frame_class[ch];

    sbr->bs_frame_class[ch] = (uint8_t)faad_getbits(ld, 2

        DEBUGVAR(1,248,"sbr_grid(): bs_frame_class"));

    switch (sbr->bs_frame_class[ch])

    {

    case FIXFIX:

        i = (uint8_t)faad_getbits(ld, 2

            DEBUGVAR(1,249,"sbr_grid(): bs_num_env_raw"));

        bs_num_env = min(1u << i, 5u);

        i = (uint8_t)faad_get1bit(ld

            DEBUGVAR(1,250,"sbr_grid(): bs_freq_res_flag"));

        for (env = 0; env < bs_num_env; env++)

            sbr->f[ch][env] = i;

        sbr->abs_bord_lead[ch] = 0;

        sbr->abs_bord_trail[ch] = sbr->numTimeSlots;

        sbr->n_rel_lead[ch] = bs_num_env - 1;

        sbr->n_rel_trail[ch] = 0;

        break;

    case FIXVAR:

        bs_abs_bord = (uint8_t)faad_getbits(ld, 2

            DEBUGVAR(1,251,"sbr_grid(): bs_abs_bord")) + sbr->numTimeSlots;

        bs_num_env = (uint8_t)faad_getbits(ld, 2

            DEBUGVAR(1,252,"sbr_grid(): bs_num_env")) + 1;

        for (rel = 0; rel < bs_num_env-1; rel++)

        {

            sbr->bs_rel_bord[ch][rel] = 2 * (uint8_t)faad_getbits(ld, 2

                DEBUGVAR(1,253,"sbr_grid(): bs_rel_bord")) + 2;

        }

        j = bs_num_env;

        i = sbr_log2(j + 1);

        sbr->bs_pointer[ch] = (uint8_t)faad_getbits(ld, i

            DEBUGVAR(1,254,"sbr_grid(): bs_pointer"));

        sbr->bs_pointer[ch] = min(sbr->bs_pointer[ch], j);

        for (env = 0; env < bs_num_env; env++)

        {

            sbr->f[ch][bs_num_env - env - 1] = (uint8_t)faad_get1bit(ld

                DEBUGVAR(1,255,"sbr_grid(): bs_freq_res"));

        }

        sbr->abs_bord_lead[ch] = 0;

        sbr->abs_bord_trail[ch] = bs_abs_bord;

        sbr->n_rel_lead[ch] = 0;

        sbr->n_rel_trail[ch] = bs_num_env - 1;

        break;

    case VARFIX:

        bs_abs_bord = (uint8_t)faad_getbits(ld, 2

            DEBUGVAR(1,256,"sbr_grid(): bs_abs_bord"));

        bs_num_env = (uint8_t)faad_getbits(ld, 2

            DEBUGVAR(1,257,"sbr_grid(): bs_num_env")) + 1;

        for (rel = 0; rel < bs_num_env-1; rel++)

        {

            sbr->bs_rel_bord[ch][rel] = 2 * (uint8_t)faad_getbits(ld, 2

                DEBUGVAR(1,258,"sbr_grid(): bs_rel_bord")) + 2;

        }

        j = bs_num_env;

        i = sbr_log2(j + 1);

        sbr->bs_pointer[ch] = (uint8_t)faad_getbits(ld, i

            DEBUGVAR(1,259,"sbr_grid(): bs_pointer"));

        sbr->bs_pointer[ch] = min(sbr->bs_pointer[ch], j);

        for (env = 0; env < bs_num_env; env++)

        {

            sbr->f[ch][env] = (uint8_t)faad_get1bit(ld

                DEBUGVAR(1,260,"sbr_grid(): bs_freq_res"));

        }

        sbr->abs_bord_lead[ch] = bs_abs_bord;

        sbr->abs_bord_trail[ch] = sbr->numTimeSlots;

        sbr->n_rel_lead[ch] = bs_num_env - 1;

        sbr->n_rel_trail[ch] = 0;

        break;

    case VARVAR:

        bs_abs_bord = (uint8_t)faad_getbits(ld, 2

            DEBUGVAR(1,261,"sbr_grid(): bs_abs_bord_0"));

        bs_abs_bord_1 = (uint8_t)faad_getbits(ld, 2

            DEBUGVAR(1,262,"sbr_grid(): bs_abs_bord_1")) + sbr->numTimeSlots;

        sbr->bs_num_rel_0[ch] = (uint8_t)faad_getbits(ld, 2

            DEBUGVAR(1,263,"sbr_grid(): bs_num_rel_0"));

        sbr->bs_num_rel_1[ch] = (uint8_t)faad_getbits(ld, 2

            DEBUGVAR(1,264,"sbr_grid(): bs_num_rel_1"));

        bs_num_env = min(5, sbr->bs_num_rel_0[ch] + sbr->bs_num_rel_1[ch] + 1);

        for (rel = 0; rel < sbr->bs_num_rel_0[ch]; rel++)

        {

            sbr->bs_rel_bord_0[ch][rel] = 2 * (uint8_t)faad_getbits(ld, 2

                DEBUGVAR(1,265,"sbr_grid(): bs_rel_bord")) + 2;

        }

        for(rel = 0; rel < sbr->bs_num_rel_1[ch]; rel++)

        {

            sbr->bs_rel_bord_1[ch][rel] = 2 * (uint8_t)faad_getbits(ld, 2

                DEBUGVAR(1,266,"sbr_grid(): bs_rel_bord")) + 2;

        }

        j = sbr->bs_num_rel_0[ch] + sbr->bs_num_rel_1[ch] + 1;

        i = sbr_log2(j + 1);

        sbr->bs_pointer[ch] = (uint8_t)faad_getbits(ld, i

            DEBUGVAR(1,267,"sbr_grid(): bs_pointer"));

        sbr->bs_pointer[ch] = min(sbr->bs_pointer[ch], j);

        for (env = 0; env < bs_num_env; env++)

        {

            sbr->f[ch][env] = (uint8_t)faad_get1bit(ld

                DEBUGVAR(1,268,"sbr_grid(): bs_freq_res"));

        }

        sbr->abs_bord_lead[ch] = bs_abs_bord;

        sbr->abs_bord_trail[ch] = bs_abs_bord_1;

        sbr->n_rel_lead[ch] = sbr->bs_num_rel_0[ch];

        sbr->n_rel_trail[ch] = sbr->bs_num_rel_1[ch];

        break;

    }

    if (sbr->bs_frame_class[ch] == VARVAR)

        sbr->L_E[ch] = min(bs_num_env, 5);

    else

        sbr->L_E[ch] = min(bs_num_env, 4);

    if (sbr->L_E[ch] <= 0)

        return 1;

    if (sbr->L_E[ch] > 1)

        sbr->L_Q[ch] = 2;

    else

        sbr->L_Q[ch] = 1;

    /* TODO: this code can probably be integrated into the code above! */

    if ((result = envelope_time_border_vector(sbr, ch)) > 0)

    {

        sbr->bs_frame_class[ch] = saved_frame_class;

        sbr->L_E[ch] = saved_L_E;

        sbr->L_Q[ch] = saved_L_Q;

        return result;

    }

    noise_floor_time_border_vector(sbr, ch);

#if 0

    for (env = 0; env < bs_num_env; env++)

    {

        printf("freq_res[ch:%d][env:%d]: %d\n", ch, env, sbr->f[ch][env]);

    }

#endif

    return 0;

}

/* table 8 */

static void sbr_dtdf(bitfile *ld, sbr_info *sbr, uint8_t ch)

{

    uint8_t i;

    for (i = 0; i < sbr->L_E[ch]; i++)

    {

        sbr->bs_df_env[ch][i] = faad_get1bit(ld

            DEBUGVAR(1,269,"sbr_dtdf(): bs_df_env"));

    }

    for (i = 0; i < sbr->L_Q[ch]; i++)

    {

        sbr->bs_df_noise[ch][i] = faad_get1bit(ld

            DEBUGVAR(1,270,"sbr_dtdf(): bs_df_noise"));

    }

}

/* table 9 */

static void invf_mode(bitfile *ld, sbr_info *sbr, uint8_t ch)

{

    uint8_t n;

    for (n = 0; n < sbr->N_Q; n++)

    {

        sbr->bs_invf_mode[ch][n] = (uint8_t)faad_getbits(ld, 2

            DEBUGVAR(1,271,"invf_mode(): bs_invf_mode"));

    }

}

static uint16_t sbr_extension(bitfile *ld, sbr_info *sbr,

                              uint8_t bs_extension_id, uint16_t num_bits_left)

{

#ifdef PS_DEC

    uint8_t header;

    uint16_t ret;

#endif

    (void)num_bits_left;  /* TODO: remove or actually use parameter. */

    switch (bs_extension_id)

    {

#ifdef PS_DEC

    case EXTENSION_ID_PS:

        if (!sbr->ps)

        {

            sbr->ps = ps_init(get_sr_index(sbr->sample_rate), sbr->numTimeSlotsRate);

        }

        if (sbr->psResetFlag)

        {

            sbr->ps->header_read = 0;

        }

        ret = ps_data(sbr->ps, ld, &header);

        /* enable PS if and only if: a header has been decoded */

        if (sbr->ps_used == 0 && header == 1)

        {

            sbr->ps_used = 1;

        }

        if (header == 1)

        {

            sbr->psResetFlag = 0;

        }

        return ret;

#endif

#ifdef DRM_PS

    case DRM_PARAMETRIC_STEREO:

        /* If not expected then only decode but do not expose. */

        if (sbr->Is_DRM_SBR)

        {

            sbr->ps_used = 1;

        }

        if (!sbr->drm_ps)

        {

            sbr->drm_ps = drm_ps_init();

        }

        return drm_ps_data(sbr->drm_ps, ld);

#endif

    default:

        sbr->bs_extension_data = (uint8_t)faad_getbits(ld, 6