/*
 *  tooLAME: an optimized mpeg 1/2 layer 2 audio encoder
 *
 *  Copyright (C) 2001-2004 Michael Cheng
 *
 *  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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *  
 */


#include <stdio.h>
#include <stdlib.h>

#include "common.h"
#include "toolame.h"
#include "toolame_global_flags.h"
#include "bitbuffer.h"
#include "mem.h"


/*create bit buffer*/
bit_stream* buffer_init( unsigned char *buffer, int buffer_size )
{
	bit_stream* bs = (bit_stream *)toolame_malloc(sizeof(bit_stream),"bit_stream");
	
	bs->buf = buffer;
	bs->buf_size = buffer_size;
	bs->buf_byte_idx = 0;
	bs->buf_bit_idx = 8;
	bs->totbit = 0;
	bs->eob = FALSE;
	bs->eobs = FALSE;
	
	return bs;
}

/* Dellocate bit buffer */
void buffer_deinit( bit_stream ** bs )
{
	toolame_free( (void**)bs );
}


/*write 1 bit from the bit stream */
void buffer_put1bit (bit_stream * bs, int bit)
{
  bs->totbit++;

  bs->buf[bs->buf_byte_idx] |= (bit & 0x1) << (bs->buf_bit_idx - 1);
  bs->buf_bit_idx--;
  if (!bs->buf_bit_idx) {
    bs->buf_bit_idx = 8;
    bs->buf_byte_idx++;
    if (bs->buf_byte_idx >= bs->buf_size) {
      //empty_buffer (bs, minimum);
      fprintf(stdout,"buffer_put1bit: error. bit_stream buffer needs to be bigger\n");
      exit(99);
    }
    bs->buf[bs->buf_byte_idx] = 0;
  }
}

/*write N bits into the bit stream */
INLINE void buffer_putbits (bit_stream * bs, unsigned int val, int N)
{
  static const int putmask[9] = { 0x0, 0x1, 0x3, 0x7, 0xf, 0x1f, 0x3f, 0x7f, 0xff };
  register int j = N;
  register int k, tmp;

  bs->totbit += N;
  while (j > 0) {
    k = MIN (j, bs->buf_bit_idx);
    tmp = val >> (j - k);
    bs->buf[bs->buf_byte_idx] |= (tmp & putmask[k]) << (bs->buf_bit_idx - k);
    bs->buf_bit_idx -= k;
    if (!bs->buf_bit_idx) {
      bs->buf_bit_idx = 8;
      bs->buf_byte_idx++;
      if (bs->buf_byte_idx >= bs->buf_size) {
	//empty_buffer (bs, minimum);
	fprintf(stdout,"buffer_putbits: error. bit_stream buffer needs to be bigger\n");
	exit(99);	
      }
      bs->buf[bs->buf_byte_idx] = 0;
    }
    j -= k;
  }
}

/*return the current bit stream length (in bits)*/
unsigned long buffer_sstell (bit_stream * bs)
{
  return (bs->totbit);
}

