/* Time-stamp: <2005-09-17 21:55:20 jcs>
|
|  Copyright (C) 2002-2005 Jorg Schuler <jcsjcs at users sourceforge net>
|  Part of the gtkpod project.
| 
|  URL: http://www.gtkpod.org/
|  URL: http://gtkpod.sourceforge.net/
|
|  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
|
|  iTunes and iPod are trademarks of Apple
|
|  This product is not supported/written/published by Apple!
|
|  $Id: wavfile.c 629 2005-09-20 09:50:13Z jcsjcs $
*/

#ifdef HAVE_CONFIG_H
#  include <config.h>
#endif

#include "charset.h"
#include "itdb.h"
#include "misc.h"
#include "wavfile.h"

#include <string.h>

/* Code for determining the playlength is strongly based on xmms code
 * (wav.c) which is distributed under the terms of the GPL V2 or any
 * later version. */
/* Original copyright notice (they are not involved with gtkpod,
 * however):
 * Copyright (C) 1998-2000 Peter Alm, Mikael Alm, Olle Hallnas,
 * Thomas Nilsson and 4Front Technologies */

#define	WAVE_FORMAT_UNKNOWN		(0x0000)
#define	WAVE_FORMAT_PCM			(0x0001)
#define	WAVE_FORMAT_ADPCM		(0x0002)
#define	WAVE_FORMAT_ALAW		(0x0006)
#define	WAVE_FORMAT_MULAW		(0x0007)
#define	WAVE_FORMAT_OKI_ADPCM		(0x0010)
#define	WAVE_FORMAT_DIGISTD		(0x0015)
#define	WAVE_FORMAT_DIGIFIX		(0x0016)
#define	IBM_FORMAT_MULAW	(0x0101)
#define	IBM_FORMAT_ALAW			(0x0102)
#define	IBM_FORMAT_ADPCM	(0x0103)

typedef struct
{
	FILE *file;
	short format_tag, channels, block_align, bits_per_sample, eof, going;
	long samples_per_sec, avg_bytes_per_sec;
}
WaveFile;


static gint read_le_long(FILE * file, glong *ret)
{
	guchar buf[4];

	if (fread(buf, 1, 4, file) != 4)
		return 0;

	*ret = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0];
	return TRUE;
}

static gint read_le_short(FILE * file, gshort *ret)
{
	guchar buf[2];

	if (fread(buf, 1, 2, file) != 2)
		return 0;

	*ret = (buf[1] << 8) | buf[0];
	return TRUE;
}



Track *wav_get_file_info (gchar *filename)
{
    Track *track = NULL;
    gchar *fn;
    gchar magic[4];
    gulong len;
    WaveFile *wav_file;

    wav_file = g_malloc(sizeof (WaveFile));
    memset(wav_file, 0, sizeof (WaveFile));
    if (!(wav_file->file = fopen(filename, "rb")))
    {
	gchar *fn = charset_to_utf8 (filename);
	gtkpod_warning (_("Could not open '%s' for reading.\n"), fn);
	g_free (fn);
	g_free(wav_file);
	wav_file = NULL;
	return NULL;
    }

    fread(magic, 1, 4, wav_file->file);
    if (strncmp(magic, "RIFF", 4) != 0)  goto file_error;
    read_le_long(wav_file->file, &len);
    fread(magic, 1, 4, wav_file->file);
    if (strncmp(magic, "WAVE", 4) != 0)  goto file_error;
    for (;;)
    {
	fread(magic, 1, 4, wav_file->file);
	if (!read_le_long(wav_file->file, &len)) goto file_error;
	if (!strncmp("fmt ", magic, 4))          break;
	fseek(wav_file->file, len, SEEK_CUR);
    }
    if (len < 16)  goto file_error;
    read_le_short(wav_file->file, &wav_file->format_tag);
    switch (wav_file->format_tag)
    {
    case WAVE_FORMAT_UNKNOWN:
    case WAVE_FORMAT_ALAW:
    case WAVE_FORMAT_MULAW:
    case WAVE_FORMAT_ADPCM:
    case WAVE_FORMAT_OKI_ADPCM:
    case WAVE_FORMAT_DIGISTD:
    case WAVE_FORMAT_DIGIFIX:
    case IBM_FORMAT_MULAW:
    case IBM_FORMAT_ALAW:
    case IBM_FORMAT_ADPCM:
	goto file_error;
    }
    read_le_short(wav_file->file, &wav_file->channels);
    read_le_long(wav_file->file, &wav_file->samples_per_sec);
    read_le_long(wav_file->file, &wav_file->avg_bytes_per_sec);
    read_le_short(wav_file->file, &wav_file->block_align);
    read_le_short(wav_file->file, &wav_file->bits_per_sample);
/*    if (wav_file->bits_per_sample != 8 && wav_file->bits_per_sample != 16)
      goto file_error;*/
    len -= 16;
    if (len)  fseek(wav_file->file, len, SEEK_CUR);

    for (;;)
    {
	fread(magic, 4, 1, wav_file->file);

	if (!read_le_long(wav_file->file, &len))  goto file_error;
	if (!strncmp("data", magic, 4))
	    break;
	fseek(wav_file->file, len, SEEK_CUR);
    }

    track = gp_track_new ();

    track->bitrate = wav_file->samples_per_sec * wav_file->channels * wav_file->bits_per_sample;
    track->samplerate = wav_file->samples_per_sec;
    track->tracklen = 1000 * ((double)8*len / track->bitrate);
    track->bitrate /= 1000; /* change to kbps */
    track->filetype = g_strdup ("WAV audio file");

    fclose(wav_file->file);
    g_free(wav_file);
    wav_file = NULL;
    return track;


  file_error:
    fclose(wav_file->file);
    g_free(wav_file);
    wav_file = NULL;
    fn = charset_to_utf8 (filename);
    gtkpod_warning (_("%s does not appear to be a supported wav file.\n"), fn);
    g_free (fn);
    return NULL;
}


gboolean wav_write_file_info (gchar *filename, Track *track)
{
    /* tags cannot be saved to wav files */
    return TRUE;
}