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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2005 Thom Johansen
* Copyright (C) 2010 Andree Buschmann
*
* 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 <string.h>
#include <inttypes.h>
#include "system.h"
#include "metadata.h"
#include "metadata_common.h"
#include "metadata_parsers.h"
#include "logf.h"
#include "replaygain.h"
#include "fixedpoint.h"
/* Needed for replay gain and clipping prevention of SV8 files. */
#define SV8_TO_SV7_CONVERT_GAIN (6482) /* 64.82 * 100, MPC_OLD_GAIN_REF */
#define SV8_TO_SV7_CONVERT_PEAK (23119) /* 256 * 20 * log10(32768) */
static int set_replaygain_sv7(struct mp3entry* id3,
bool album,
long value,
long used)
{
long gain = (int16_t) ((value >> 16) & 0xffff);
long peak = (uint16_t) (value & 0xffff);
/* We use a peak value of 0 to indicate a given gain type isn't used. */
if (peak != 0) {
/* Save the ReplayGain data to id3-structure for further processing. */
used += parse_replaygain_int(album, gain * 512 / 100, peak << 9,
id3, id3->toc + used, sizeof(id3->toc) - used);
}
return used;
}
static int set_replaygain_sv8(struct mp3entry* id3,
bool album,
long gain,
long peak,
long used)
{
gain = (long)(SV8_TO_SV7_CONVERT_GAIN - ((gain*100)/256));
/* Transform SV8's logarithmic peak representation to the desired linear
* representation: linear = pow(10, peak/256/20).
*
* FP_BITS = 24 bits = desired fp representation for dsp routines
* FRAC_BITS = 12 bits = resolution used for fp_bits
* fp_factor(peak*(1<<FRAC_BITS)/256, FRAC_BITS) << (FP_BITS-FRAC_BITS)
**/
peak = (fp_factor((peak-SV8_TO_SV7_CONVERT_PEAK)*16, 12) << 12);
/* We use a peak value of 0 to indicate a given gain type isn't used. */
if (peak != 0) {
/* Save the ReplayGain data to id3-structure for further processing. */
used += parse_replaygain_int(album, gain * 512 / 100, peak,
id3, id3->toc + used, sizeof(id3->toc) - used);
}
return used;
}
static int sv8_get_size(uint8_t *buffer, int index, uint64_t *p_size)
{
unsigned char tmp;
uint64_t size = 0;
do {
tmp = buffer[index++];
size = (size << 7) | (tmp & 0x7F);
} while((tmp & 0x80));
*p_size = size;
return index;
}
bool get_musepack_metadata(int fd, struct mp3entry *id3)
{
static const int32_t sfreqs[4] = { 44100, 48000, 37800, 32000 };
uint32_t header[8];
uint64_t samples = 0;
int i;
if (!skip_id3v2(fd, id3))
return false;
if (read(fd, header, 4*8) != 4*8) return false;
/* Musepack files are little endian, might need swapping */
for (i = 1; i < 8; i++)
header[i] = letoh32(header[i]);
if (!memcmp(header, "MP+", 3)) { /* Compare to sig "MP+" */
unsigned int streamversion;
header[0] = letoh32(header[0]);
streamversion = (header[0] >> 24) & 15;
if (streamversion == 7) {
unsigned int gapless = (header[5] >> 31) & 0x0001;
unsigned int last_frame_samples = (header[5] >> 20) & 0x07ff;
unsigned int bufused = 0;
id3->frequency = sfreqs[(header[2] >> 16) & 0x0003];
samples = (uint64_t)header[1]*1152; /* 1152 is mpc frame size */
if (gapless)
samples -= 1152 - last_frame_samples;
else
samples -= 481; /* Musepack subband synth filter delay */
bufused = set_replaygain_sv7(id3, false, header[3], bufused);
bufused = set_replaygain_sv7(id3, true , header[4], bufused);
} else {
return false; /* only SV7 is allowed within a "MP+" signature */
}
} else if (!memcmp(header, "MPCK", 4)) { /* Compare to sig "MPCK" */
uint8_t sv8_header[32];
/* 4 bytes 'MPCK' */
lseek(fd, 4, SEEK_SET);
if (read(fd, sv8_header, 2) != 2) return false; /* read frame ID */
if (!memcmp(sv8_header, "SH", 2)) { /* Stream Header ID */
int32_t k = 0;
uint32_t streamversion;
uint64_t size = 0; /* tag size */
uint64_t dummy = 0; /* used to dummy read data from header */
/* 4 bytes 'MPCK' + 2 'SH' */
lseek(fd, 6, SEEK_SET);
if (read(fd, sv8_header, 32) != 32) return false;
/* Read the size of 'SH'-tag */
k = sv8_get_size(sv8_header, k, &size);
/* Skip crc32 */
k += 4;
/* Read stream version */
streamversion = sv8_header[k++];
if (streamversion != 8) return false; /* Only SV8 is allowed. */
/* Number of samples */
k = sv8_get_size(sv8_header, k, &samples);
/* Number of leading zero-samples */
k = sv8_get_size(sv8_header, k, &dummy);
/* Sampling frequency */
id3->frequency = sfreqs[(sv8_header[k++] >> 5) & 0x0003];
/* Number of channels */
id3->channels = (sv8_header[k++] >> 4) + 1;
/* Skip to next tag: k = size -2 */
k = size - 2;
if (!memcmp(sv8_header+k, "RG", 2)) { /* Replay Gain ID */
long peak, gain;
int bufused = 0;
k += 2; /* 2 bytes 'RG' */
/* sv8_get_size must be called to skip the right amount of
* bits within the header data. */
k = sv8_get_size(sv8_header, k, &size);
/* Read and set replay gain */
if (sv8_header[k++] == 1) {
/* Title's peak and gain */
gain = (int16_t) ((sv8_header[k]<<8) + sv8_header[k+1]); k += 2;
peak = (uint16_t)((sv8_header[k]<<8) + sv8_header[k+1]); k += 2;
bufused += set_replaygain_sv8(id3, false, gain, peak, bufused);
/* Album's peak and gain */
gain = (int16_t) ((sv8_header[k]<<8) + sv8_header[k+1]); k += 2;
peak = (uint16_t)((sv8_header[k]<<8) + sv8_header[k+1]); k += 2;
bufused += set_replaygain_sv8(id3, true , gain, peak, bufused);
}
}
} else {
/* No sv8 stream header found */
return false;
}
} else {
return false; /* SV4-6 is not supported anymore */
}
id3->vbr = true;
/* Estimate bitrate, we should probably subtract the various header sizes
here for super-accurate results */
id3->length = ((int64_t) samples * 1000) / id3->frequency;
if (id3->length <= 0)
{
logf("mpc length invalid!");
return false;
}
id3->filesize = filesize(fd);
id3->bitrate = id3->filesize * 8 / id3->length;
return true;
}
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