/*

 * common.c: some common bitstream operations

 *

 * Copyright (C) 1999-2010 The L.A.M.E. project

 *

 * Initially written by Michael Hipp, see also AUTHORS and README.

 *  

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Library General Public

 * License as published by the Free Software Foundation; either

 * version 2 of the License, or (at your option) any later version.

 *

 * This library 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

 * Library General Public License for more details.

 *

 * You should have received a copy of the GNU Library General Public

 * License along with this library; if not, write to the

 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,

 * Boston, MA 02111-1307, USA.

 */

/* $Id: common.c,v 1.42 2017/08/19 14:20:27 robert Exp $ */

#ifdef HAVE_CONFIG_H

#include <config.h>

#endif

#include <ctype.h>

#include <stdlib.h>

#include <signal.h>

#ifdef HAVE_FCNTL_H

#include <fcntl.h>

#endif

#ifdef macintosh

#include   <types.h>

#include   <stat.h>

#else

#include  <sys/types.h>

#include  <sys/stat.h>

#endif

#include <assert.h>

#include "common.h"

#ifdef WITH_DMALLOC

#include <dmalloc.h>

#endif

/* In C++ the array first must be prototyped, why ? */

    /* *INDENT-OFF* */

const int tabsel_123 [2] [3] [16] = {

   { {0,32,64,96,128,160,192,224,256,288,320,352,384,416,448,},

     {0,32,48,56, 64, 80, 96,112,128,160,192,224,256,320,384,},

     {0,32,40,48, 56, 64, 80, 96,112,128,160,192,224,256,320,} },

   { {0,32,48,56,64,80,96,112,128,144,160,176,192,224,256,},

     {0,8,16,24,32,40,48,56,64,80,96,112,128,144,160,},

     {0,8,16,24,32,40,48,56,64,80,96,112,128,144,160,} }

};

const long freqs[9] = { 44100, 48000, 32000,

                        22050, 24000, 16000,

                        11025, 12000,  8000 };

    /* *INDENT-ON* */

real    muls[27][64];

#if 0

static void

get_II_stuff(struct frame *fr)

{

    /* *INDENT-OFF* */

  static const int translate [3] [2] [16] =   /* char ? */

   { { { 0,2,2,2,2,2,2,0,0,0,1,1,1,1,1,0 } ,

       { 0,2,2,0,0,0,1,1,1,1,1,1,1,1,1,0 } } ,

     { { 0,2,2,2,2,2,2,0,0,0,0,0,0,0,0,0 } ,

       { 0,2,2,0,0,0,0,0,0,0,0,0,0,0,0,0 } } ,

     { { 0,3,3,3,3,3,3,0,0,0,1,1,1,1,1,0 } ,

       { 0,3,3,0,0,0,1,1,1,1,1,1,1,1,1,0 } } };

    /* *INDENT-ON* */

    int     table, sblim;

    static const struct al_table2 *tables[5] = { alloc_0, alloc_1, alloc_2, alloc_3, alloc_4 };

    static int sblims[5] = { 27, 30, 8, 12, 30 };

    if (fr->lsf)

        table = 4;

    else

        table = translate[fr->sampling_frequency][2 - fr->stereo][fr->bitrate_index];

    sblim = sblims[table];

    fr->alloc = tables[table];

    fr->II_sblimit = sblim;

}

#endif

#define HDRCMPMASK 0xfffffd00

#define MAX_INPUT_FRAMESIZE 4096

int

head_check(unsigned long head, int check_layer)

{

    /*

       look for a valid header.  

       if check_layer > 0, then require that

       nLayer = check_layer.  

     */

    /* bits 13-14 = layer 3 */

    int     nLayer = 4 - ((head >> 17) & 3);

    if ((head & 0xffe00000) != 0xffe00000) {

        /* syncword */

        return FALSE;

    }

    if (nLayer == 4)

        return FALSE;

    if (check_layer > 0 && nLayer != check_layer)

        return FALSE;

    if (((head >> 12) & 0xf) == 0xf) {

        /* bits 16,17,18,19 = 1111  invalid bitrate */

        return FALSE;

    }

    if (((head >> 10) & 0x3) == 0x3) {

        /* bits 20,21 = 11  invalid sampling freq */

        return FALSE;

    }

    if ((head & 0x3) == 0x2)

        /* invalid emphasis */

        return FALSE;

    return TRUE;

}

#if 0

static void

print_header(PMPSTR mp, struct frame *fr)

{

    static const char *modes[4] = { "Stereo", "Joint-Stereo", "Dual-Channel", "Single-Channel" };

    static const char *layers[4] = { "Unknown", "I", "II", "III" };

    lame_report_fnc(mp->report_msg, "MPEG %s, Layer: %s, Freq: %ld, mode: %s, modext: %d, BPF : %d\n",

            fr->mpeg25 ? "2.5" : (fr->lsf ? "2.0" : "1.0"),

            layers[fr->lay], freqs[fr->sampling_frequency],

            modes[fr->mode], fr->mode_ext, fr->framesize + 4);

    lame_report_fnc(mp->report_msg, "Channels: %d, copyright: %s, original: %s, CRC: %s, emphasis: %d.\n",

            fr->stereo, fr->copyright ? "Yes" : "No",

            fr->original ? "Yes" : "No", fr->error_protection ? "Yes" : "No", fr->emphasis);

    lame_report_fnc(mp->report_msg, "Bitrate: %d Kbits/s, Extension value: %d\n",

            tabsel_123[fr->lsf][fr->lay - 1][fr->bitrate_index], fr->extension);

}

static void

print_header_compact(PMPSTR mp, struct frame *fr)

{

    static const char *modes[4] = { "stereo", "joint-stereo", "dual-channel", "mono" };

    static const char *layers[4] = { "Unknown", "I", "II", "III" };

    lame_report_fnc(mp->report_err, "MPEG %s layer %s, %d kbit/s, %ld Hz %s\n",

            fr->mpeg25 ? "2.5" : (fr->lsf ? "2.0" : "1.0"),

            layers[fr->lay],

            tabsel_123[fr->lsf][fr->lay - 1][fr->bitrate_index],

            freqs[fr->sampling_frequency], modes[fr->mode]);

}

#endif

/*

 * decode a header and write the information

 * into the frame structure

 */

int

decode_header(PMPSTR mp, struct frame *fr, unsigned long newhead)

{

    if (newhead & (1 << 20)) {

        fr->lsf = (newhead & (1 << 19)) ? 0x0 : 0x1;

        fr->mpeg25 = 0;

    }

    else {

        fr->lsf = 1;

        fr->mpeg25 = 1;

    }

    fr->lay = 4 - ((newhead >> 17) & 3);

    if (fr->lay != 3 && fr->mpeg25) {

        lame_report_fnc(mp->report_err, "MPEG-2.5 is supported by Layer3 only\n");

        return 0;

    }

    if (((newhead >> 10) & 0x3) == 0x3) {

        lame_report_fnc(mp->report_err, "Stream error\n");

        return 0;

    }

    if (fr->mpeg25) {

        fr->sampling_frequency = 6 + ((newhead >> 10) & 0x3);

    }

    else

        fr->sampling_frequency = ((newhead >> 10) & 0x3) + (fr->lsf * 3);

    fr->error_protection = ((newhead >> 16) & 0x1) ^ 0x1;

    if (fr->mpeg25)     /* allow Bitrate change for 2.5 ... */

        fr->bitrate_index = ((newhead >> 12) & 0xf);

    fr->bitrate_index = ((newhead >> 12) & 0xf);

    fr->padding = ((newhead >> 9) & 0x1);

    fr->extension = ((newhead >> 8) & 0x1);

    fr->mode = ((newhead >> 6) & 0x3);

    fr->mode_ext = ((newhead >> 4) & 0x3);

    fr->copyright = ((newhead >> 3) & 0x1);

    fr->original = ((newhead >> 2) & 0x1);

    fr->emphasis = newhead & 0x3;

    fr->stereo = (fr->mode == MPG_MD_MONO) ? 1 : 2;

    switch (fr->lay) {

    case 1:

        fr->framesize = (long) tabsel_123[fr->lsf][0][fr->bitrate_index] * 12000;

        fr->framesize /= freqs[fr->sampling_frequency];

        fr->framesize = ((fr->framesize + fr->padding) << 2) - 4;

        fr->down_sample = 0;

        fr->down_sample_sblimit = SBLIMIT >> (fr->down_sample);

        break;

    case 2:

        fr->framesize = (long) tabsel_123[fr->lsf][1][fr->bitrate_index] * 144000;

        fr->framesize /= freqs[fr->sampling_frequency];

        fr->framesize += fr->padding - 4;

        fr->down_sample = 0;

        fr->down_sample_sblimit = SBLIMIT >> (fr->down_sample);

        break;

    case 3:

#if 0

        fr->do_layer = do_layer3;

        if (fr->lsf)

            ssize = (fr->stereo == 1) ? 9 : 17;

        else

            ssize = (fr->stereo == 1) ? 17 : 32;

#endif

#if 0

        if (fr->error_protection)

            ssize += 2;

#endif

        if (fr->framesize > MAX_INPUT_FRAMESIZE) {

            lame_report_fnc(mp->report_err, "Frame size too big.\n");

            fr->framesize = MAX_INPUT_FRAMESIZE;

            return (0);

        }

        if (fr->bitrate_index == 0)

            fr->framesize = 0;

        else {

            fr->framesize = (long) tabsel_123[fr->lsf][2][fr->bitrate_index] * 144000;

            fr->framesize /= freqs[fr->sampling_frequency] << (fr->lsf);

            fr->framesize = fr->framesize + fr->padding - 4;

        }

        break;

    default:

        lame_report_fnc(mp->report_err, "Sorry, layer %d not supported\n", fr->lay);

        return (0);

    }

    /*    print_header(mp, fr); */

    return 1;

}

unsigned int

getbits(PMPSTR mp, int number_of_bits)

{

    unsigned long rval;

    if (number_of_bits <= 0 || !mp->wordpointer)

        return 0;

    {

        rval = mp->wordpointer[0];

        rval <<= 8;

        rval |= mp->wordpointer[1];

        rval <<= 8;

        rval |= mp->wordpointer[2];

        rval <<= mp->bitindex;

        rval &= 0xffffff;

        mp->bitindex += number_of_bits;

        rval >>= (24 - number_of_bits);

        mp->wordpointer += (mp->bitindex >> 3);

        mp->bitindex &= 7;

    }

    return rval;

}

unsigned int

getbits_fast(PMPSTR mp, int number_of_bits)

{

    unsigned long rval;

    {

        rval = mp->wordpointer[0];

        rval <<= 8;

        rval |= mp->wordpointer[1];

        rval <<= mp->bitindex;

        rval &= 0xffff;

        mp->bitindex += number_of_bits;

        rval >>= (16 - number_of_bits);

        mp->wordpointer += (mp->bitindex >> 3);

        mp->bitindex &= 7;

    }

    return rval;

}

unsigned char

get_leq_8_bits(PMPSTR mp, unsigned int number_of_bits)

{

    assert(number_of_bits <= 8);

    return (unsigned char) getbits_fast(mp, number_of_bits);

}

unsigned short

get_leq_16_bits(PMPSTR mp, unsigned int number_of_bits)

{

    assert(number_of_bits <= 16);

    return (unsigned short) getbits_fast(mp, number_of_bits);

}

int

set_pointer(PMPSTR mp, long backstep)

{

    unsigned char *bsbufold;

    if (mp->fsizeold < 0 && backstep > 0) {

        lame_report_fnc(mp->report_err, "hip: Can't step back %ld bytes!\n", backstep);

        return MP3_ERR;

    }

    bsbufold = mp->bsspace[1 - mp->bsnum] + 512;

    mp->wordpointer -= backstep;

    if (backstep)

        memcpy(mp->wordpointer, bsbufold + mp->fsizeold - backstep, (size_t) backstep);

    mp->bitindex = 0;

    return MP3_OK;

}