/*
     This file is part of libextractor.
     (C) 2004, 2009 Vidyut Samanta and Christian Grothoff

     libextractor 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, or (at your
     option) any later version.

     libextractor 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 libextractor; see the file COPYING.  If not, write to the
     Free Software Foundation, Inc., 59 Temple Place - Suite 330,
     Boston, MA 02111-1307, USA.

     This code was based on bitcollider 0.6.0
     (PD) 2004 The Bitzi Corporation
     http://bitzi.com/
     (PD) 2001 The Bitzi Corporation
     Please see file COPYING or http://bitzi.com/publicdomain
     for more info.
*/


#include "platform.h"
#include "extractor.h"

#if BIG_ENDIAN_HOST
static short
toLittleEndian16 (short in)
{
  char *ptr = (char *) ∈

  return ((ptr[1] & 0xFF) << 8) | (ptr[0] & 0xFF);
}

static unsigned int
toLittleEndian32 (unsigned int in)
{
  char *ptr = (char *) &in;

  return ((ptr[3] & 0xFF) << 24) | ((ptr[2] & 0xFF) << 16) | ((ptr[1] & 0xFF)
                                                              << 8) | (ptr[0]
                                                                       &
                                                                       0xFF);
}
#endif


/*
  16      4 bytes  0x00000010     // Length of the fmt data (16 bytes)
  20      2 bytes  0x0001         // Format tag: 1 = PCM
  22      2 bytes  <channels>     // Channels: 1 = mono, 2 = stereo
  24      4 bytes  <sample rate>  // Samples per second: e.g., 44100
*/
int 
EXTRACTOR_wav_extract (const unsigned char *buf,
		       size_t bufLen,
		       EXTRACTOR_MetaDataProcessor proc,
		       void *proc_cls,
		       const char *options)
{
  unsigned short channels;
  unsigned short sampleSize;
  unsigned int sampleRate;
  unsigned int dataLen;
  unsigned int samples;
  char scratch[256];

  if ((bufLen < 44) ||
      (buf[0] != 'R' || buf[1] != 'I' ||
       buf[2] != 'F' || buf[3] != 'F' ||
       buf[8] != 'W' || buf[9] != 'A' ||
       buf[10] != 'V' || buf[11] != 'E' ||
       buf[12] != 'f' || buf[13] != 'm' || buf[14] != 't' || buf[15] != ' '))
    return 0;                /* not a WAV file */

  channels = *((unsigned short *) &buf[22]);
  sampleRate = *((unsigned int *) &buf[24]);
  sampleSize = *((unsigned short *) &buf[34]);
  dataLen = *((unsigned int *) &buf[40]);

#if BIG_ENDIAN_HOST
  channels = toLittleEndian16 (channels);
  sampleSize = toLittleEndian16 (sampleSize);
  sampleRate = toLittleEndian32 (sampleRate);
  dataLen = toLittleEndian32 (dataLen);
#endif

  if (sampleSize != 8 && sampleSize != 16)
    return 0;                /* invalid sample size found in wav file */
  if (channels == 0)
    return 0;                /* invalid channels value -- avoid division by 0! */
  samples = dataLen / (channels * (sampleSize >> 3));

  snprintf (scratch,
            sizeof (scratch),
            "%u ms, %d Hz, %s",
            (samples < sampleRate)
            ? (samples * 1000 / sampleRate)
            : (samples / sampleRate) * 1000,
            sampleRate, channels == 1 ? _("mono") : _("stereo"));
  if (0 != proc (proc_cls, 
		 "wav",
		 EXTRACTOR_METATYPE_RESOURCE_TYPE,
		 EXTRACTOR_METAFORMAT_UTF8,
		 "text/plain",
		 scratch,
		 strlen (scratch) +1))
    return 1;
  if (0 != proc (proc_cls, 
		 "wav",
		 EXTRACTOR_METATYPE_MIMETYPE,
		 EXTRACTOR_METAFORMAT_UTF8,
		 "text/plain",
		 "audio/x-wav",
		 strlen ("audio/x-wav") +1))
    return 1;
  return 0;
}