/*
 * Copyright (c) Michael Hipp and other authors of the mpglib project.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 */

#include "config.h"
#include <ctype.h>
#include <stdlib.h>
#include <signal.h>

#include <sys/types.h>
#ifdef HAVE_SYS_STAT_H
# include <sys/stat.h>
#endif
#include <fcntl.h>

#include "mpg123.h"

const struct parameter param = { 1 , 1 , 0 , 0 };

static 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 };

int bitindex;
unsigned char *wordpointer;
unsigned char *pcm_sample;
int pcm_point = 0;


#define HDRCMPMASK 0xfffffd00

int head_check(unsigned long head)
{
    if( (head & 0xffe00000) != 0xffe00000)
	return FALSE;
    if(!((head>>17)&3))
	return FALSE;
    if( ((head>>12)&0xf) == 0xf)
	return FALSE;
    if( ((head>>10)&0x3) == 0x3 )
	return FALSE;
    return TRUE;
}


/*
 * the code a header and write the information
 * into the frame structure
 */
int decode_header(struct frame *fr,unsigned long newhead)
{
    if(head_check(newhead) == FALSE)
      return (0);

    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->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;

    if(!fr->bitrate_index)
    {
      fprintf(stderr,"Free format not supported.\n");
      return (0);
    }

    switch(fr->lay)
    {
      case 1:
#ifdef LAYER1
#if 0
        fr->jsbound = (fr->mode == MPG_MD_JOINT_STEREO) ?
                         (fr->mode_ext<<2)+4 : 32;
#endif
        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;
#else
        fprintf(stderr,"Not supported!\n");
#endif
        break;
      case 2:
#ifdef LAYER2
#if 0
        fr->jsbound = (fr->mode == MPG_MD_JOINT_STEREO) ?
                         (fr->mode_ext<<2)+4 : fr->II_sblimit;
#endif
        fr->framesize = (long) tabsel_123[fr->lsf][1][fr->bitrate_index] * 144000;
        fr->framesize /= freqs[fr->sampling_frequency];
        fr->framesize += fr->padding - 4;
#else
        fprintf(stderr,"Not supported!\n");
#endif
        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
          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:
        fprintf(stderr,"Sorry, unknown layer type.\n");
        return (0);
    }
    return 1;
}

#if 0
void print_header(struct frame *fr)
{
	static const char * const modes[4] = { "Stereo", "Joint-Stereo", "Dual-Channel", "Single-Channel" };
	static const char * const layers[4] = { "Unknown" , "I", "II", "III" };

	fprintf(stderr,"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);
	fprintf(stderr,"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);
	fprintf(stderr,"Bitrate: %d Kbits/s, Extension value: %d\n",
		tabsel_123[fr->lsf][fr->lay-1][fr->bitrate_index],fr->extension);
}

void print_header_compact(struct frame *fr)
{
	static const char * const modes[4] = { "stereo", "joint-stereo", "dual-channel", "mono" };
	static const char * const layers[4] = { "Unknown" , "I", "II", "III" };

	fprintf(stderr,"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

unsigned int getbits(int number_of_bits)
{
  unsigned long rval;

  if(!number_of_bits)
    return 0;

  {
    rval = wordpointer[0];
    rval <<= 8;
    rval |= wordpointer[1];
    rval <<= 8;
    rval |= wordpointer[2];
    rval <<= bitindex;
    rval &= 0xffffff;

    bitindex += number_of_bits;

    rval >>= (24-number_of_bits);

    wordpointer += (bitindex>>3);
    bitindex &= 7;
  }
  return rval;
}

unsigned int getbits_fast(int number_of_bits)
{
  unsigned long rval;

  {
    rval = wordpointer[0];
    rval <<= 8;
    rval |= wordpointer[1];
    rval <<= bitindex;
    rval &= 0xffff;
    bitindex += number_of_bits;

    rval >>= (16-number_of_bits);

    wordpointer += (bitindex>>3);
    bitindex &= 7;
  }
  return rval;
}

unsigned int get1bit(void)
{
  unsigned char rval;
  rval = *wordpointer << bitindex;

  bitindex++;
  wordpointer += (bitindex>>3);
  bitindex &= 7;

  return rval>>7;
}