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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2005 Magnus Holmgren
*
* 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 software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include <ctype.h>
#include <math.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <inttypes.h>
#include "strlcpy.h"
#include "strcasecmp.h"
#include "system.h"
#include "metadata.h"
#include "debug.h"
#include "replaygain.h"
#include "fixedpoint.h"
#define FP_BITS (12)
#define FP_ONE (1 << FP_BITS)
#define FP_MIN (-48 * FP_ONE)
#define FP_MAX ( 17 * FP_ONE)
void replaygain_itoa(char* buffer, int length, long int_gain)
{
/* int_gain uses Q19.12 format. */
int one = abs(int_gain) >> FP_BITS;
int cent = ((abs(int_gain) & 0x0fff) * 100 + (FP_ONE/2)) >> FP_BITS;
snprintf(buffer, length, "%s%d.%02d dB", (int_gain<0) ? "-":"", one, cent);
}
static long fp_atof(const char* s, int precision)
{
long int_part = 0;
long int_one = BIT_N(precision);
long frac_part = 0;
long frac_count = 0;
long frac_max = ((precision * 4) + 12) / 13;
long frac_max_int = 1;
long sign = 1;
bool point = false;
while ((*s != '\0') && isspace(*s))
{
s++;
}
if (*s == '-')
{
sign = -1;
s++;
}
else if (*s == '+')
{
s++;
}
while (*s != '\0')
{
if (*s == '.')
{
if (point)
{
break;
}
point = true;
}
else if (isdigit(*s))
{
if (point)
{
if (frac_count < frac_max)
{
frac_part = frac_part * 10 + (*s - '0');
frac_count++;
frac_max_int *= 10;
}
}
else
{
int_part = int_part * 10 + (*s - '0');
}
}
else
{
break;
}
s++;
}
while (frac_count < frac_max)
{
frac_part *= 10;
frac_count++;
frac_max_int *= 10;
}
return sign * ((int_part * int_one)
+ (((int64_t) frac_part * int_one) / frac_max_int));
}
static long convert_gain(long gain)
{
/* Don't allow unreasonably low or high gain changes.
* Our math code can't handle it properly anyway. :) */
gain = MAX(gain, FP_MIN);
gain = MIN(gain, FP_MAX);
return fp_factor(gain, FP_BITS) << (24 - FP_BITS);
}
/* Get the sample scale factor in Q19.12 format from a gain value. Returns 0
* for no gain.
*
* str Gain in dB as a string. E.g., "-3.45 dB"; the "dB" part is ignored.
*/
static long get_replaygain(const char* str)
{
return fp_atof(str, FP_BITS);
}
/* Get the peak volume in Q7.24 format.
*
* str Peak volume. Full scale is specified as "1.0". Returns 0 for no peak.
*/
static long get_replaypeak(const char* str)
{
return fp_atof(str, 24);
}
/* Get a sample scale factor in Q7.24 format from a gain value.
*
* int_gain Gain in dB, multiplied by 100.
*/
long get_replaygain_int(long int_gain)
{
return convert_gain(int_gain * FP_ONE / 100);
}
/* Parse a ReplayGain tag conforming to the "VorbisGain standard". If a
* valid tag is found, update mp3entry struct accordingly. Existing values
* are not overwritten.
*
* key Name of the tag.
* value Value of the tag.
* entry mp3entry struct to update.
*/
void parse_replaygain(const char* key, const char* value,
struct mp3entry* entry)
{
if (((strcasecmp(key, "replaygain_track_gain") == 0) ||
(strcasecmp(key, "rg_radio") == 0)) &&
!entry->track_gain)
{
entry->track_level = get_replaygain(value);
entry->track_gain = convert_gain(entry->track_level);
}
else if (((strcasecmp(key, "replaygain_album_gain") == 0) ||
(strcasecmp(key, "rg_audiophile") == 0)) &&
!entry->album_gain)
{
entry->album_level = get_replaygain(value);
entry->album_gain = convert_gain(entry->album_level);
}
else if (((strcasecmp(key, "replaygain_track_peak") == 0) ||
(strcasecmp(key, "rg_peak") == 0)) &&
!entry->track_peak)
{
entry->track_peak = get_replaypeak(value);
}
else if ((strcasecmp(key, "replaygain_album_peak") == 0) &&
!entry->album_peak)
{
entry->album_peak = get_replaypeak(value);
}
}
/* Set ReplayGain values from integers. Existing values are not overwritten.
*
* album If true, set album values, otherwise set track values.
* gain Gain value in dB, multiplied by 512. 0 for no gain.
* peak Peak volume in Q7.24 format, where 1.0 is full scale. 0 for no
* peak volume.
* entry mp3entry struct to update.
*/
void parse_replaygain_int(bool album, long gain, long peak,
struct mp3entry* entry)
{
gain = gain * FP_ONE / 512;
if (album)
{
entry->album_level = gain;
entry->album_gain = convert_gain(gain);
entry->album_peak = peak;
}
else
{
entry->track_level = gain;
entry->track_gain = convert_gain(gain);
entry->track_peak = peak;
}
}
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