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/********************************************************************
*
* Copyright (c) 2002 Artur Polaczynski (Ar't) All rights reserved.
* <artii@o2.pl> LGPL-2.1
* $ArtId: info_mac.c,v 1.15 2003/04/13 11:24:10 art Exp $
********************************************************************/
/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1
* 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser 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
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "info_mac.h"
#include "is_tag.h"
#define MAC_FORMAT_FLAG_8_BIT 1 // 8-bit wave
#define MAC_FORMAT_FLAG_CRC 2 // new CRC32 error detection
#define MAC_FORMAT_FLAG_HAS_PEAK_LEVEL 4 // u-long Peak_Level after the header
#define MAC_FORMAT_FLAG_24_BIT 8 // 24-bit wave
#define MAC_FORMAT_FLAG_HAS_SEEK_ELEMENTS 16 // number of seek elements after the peak level
#define MAC_FORMAT_FLAG_CREATE_WAV_HEADER 32 // wave header not stored
struct macHeader {
char id[4]; // should equal 'MAC '
unsigned short ver; // version number * 1000 (3.81 = 3810)
unsigned short compLevel; // the compression level
unsigned short formatFlags; // any format flags (for future use)
unsigned short channels; // the number of channels (1 or 2)
unsigned long sampleRate; // the sample rate (typically 44100)
unsigned long headerBytesWAV; // the bytes after the MAC header that compose the WAV header
unsigned long terminatingBytesWAV; // the bytes after that raw data (for extended info)
unsigned long totalFrames; // the number of frames in the file
unsigned long finalFrameBlocks; // the number of samples in the final frame
unsigned long peakLevel;
unsigned short seekElements;
};
// local prototypes
static int
monkey_samples_per_frame(unsigned int versionid, unsigned int compressionlevel);
static const char *
monkey_stringify(unsigned int profile);
static const char *
monkey_stringify(unsigned int profile)
{
static const char na[] = "unknown";
static const char *Names[] = {
na, "Fast", "Normal", "High", "Extra-High", "Insane"
};
unsigned int profile2 = profile/1000;
return (profile2 >= sizeof (Names) / sizeof (*Names)) ? na : Names[(profile2)];
}
static int
monkey_samples_per_frame(unsigned int versionid, unsigned int compressionlevel)
{
if (versionid >= 3950) {
return 294912; // 73728 * 4
} else if (versionid >= 3900) {
return 73728;
} else if ((versionid >= 3800) && (compressionlevel == COMPRESSION_LEVEL_EXTRA_HIGH)) {
return 73728;
} else {
return 9216;
}
}
/*
return 0; Info has all info
return 1; File not found
return 2; no MAC file
*/
int
info_mac_read(const char *fn, StreamInfoMac * Info)
{
unsigned int HeaderData[32];
FILE *tmpFile = NULL;
long SkipSizeID3;
struct macHeader * header;
// load file
tmpFile = fopen(fn, "rb");
if (tmpFile == NULL)
return 1; // file not found or read-protected
// skip id3v2
SkipSizeID3 = is_id3v2(tmpFile);
fseek(tmpFile, SkipSizeID3, SEEK_SET);
fread((void *) HeaderData, sizeof (int), 16, tmpFile);
fseek(tmpFile, 0, SEEK_END);
Info->FileSize = ftell(tmpFile);
fclose(tmpFile);
if (0 != memcmp(HeaderData, "MAC", 3))
return 2; // no monkeyAudio file
header= (struct macHeader *) HeaderData;
Info->Version = Info->EncoderVersion = header->ver;
Info->Channels = header->channels;
Info->SampleFreq = header->sampleRate;
Info->Flags = header->formatFlags;
Info->SamplesPerFrame = monkey_samples_per_frame(header->ver, header->compLevel);
Info->BitsPerSample = (header->formatFlags & MAC_FORMAT_FLAG_8_BIT)
? 8 : ((header->formatFlags & MAC_FORMAT_FLAG_24_BIT) ? 24 : 16);
Info->PeakLevel = header->peakLevel;
// Info->PeakRatio = Info->PakLevel / pow(2, Info->bitsPerSample - 1);
Info->Frames = header->totalFrames;
Info->Samples = (Info->Frames - 1) * Info->SamplesPerFrame +
header->finalFrameBlocks;
Info->Duration = Info->SampleFreq > 0 ?
((float)Info->Samples / Info->SampleFreq)*1000 : 0;
Info->Compresion = header->compLevel;
Info->CompresionName = monkey_stringify(Info->Compresion);
Info->UncompresedSize = Info->Samples * Info->Channels *
(Info->BitsPerSample / 8);
Info->CompresionRatio =
(Info->UncompresedSize + header->headerBytesWAV) > 0 ?
Info->FileSize / (float) (Info->UncompresedSize +
header->headerBytesWAV) : 0. ;
Info->Bitrate = Info->Duration > 0 ? (((Info->Samples *
Info->Channels * Info->BitsPerSample) / (float) Info->Duration) *
Info->CompresionRatio) * 1000 : 0;
Info->PeakRatio=Info->ByteLength=0;
return 0;
}
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