/apps/metadata/mpc.c
C | 220 lines | 132 code | 36 blank | 52 comment | 28 complexity | a1a1a406084019dd7854ed65a1828bd5 MD5 | raw file
- /***************************************************************************
- * __________ __ ___.
- * 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 <stdio.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. */
- parse_replaygain_int(album, gain * 512 / 100, peak << 9, id3);
- }
-
- 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. */
- parse_replaygain_int(album, gain * 512 / 100, peak, id3);
- }
-
- 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);
-
- id3->codectype = AFMT_MPC_SV7;
- } 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);
- }
- }
-
- id3->codectype = AFMT_MPC_SV8;
- } 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;
- read_ape_tags(fd, id3);
- return true;
- }