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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2005 Dave Chapman
*
* 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 <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>
#include <inttypes.h>
#include "platform.h"
#include "metadata.h"
#include "metadata_common.h"
#include "metadata_parsers.h"
#include "logf.h"
/* A simple parser to read vital metadata from an Ogg Vorbis file.
* Can also handle parsing Ogg Speex files for metadata. Returns
* false if metadata needed by the codec couldn't be read.
*/
bool get_ogg_metadata(int fd, struct mp3entry* id3)
{
/* An Ogg File is split into pages, each starting with the string
* "OggS". Each page has a timestamp (in PCM samples) referred to as
* the "granule position".
*
* An Ogg Vorbis has the following structure:
* 1) Identification header (containing samplerate, numchannels, etc)
* 2) Comment header - containing the Vorbis Comments
* 3) Setup header - containing codec setup information
* 4) Many audio packets...
*
* An Ogg Speex has the following structure:
* 1) Identification header (containing samplerate, numchannels, etc)
* Described in this page: (http://www.speex.org/manual2/node7.html)
* 2) Comment header - containing the Vorbis Comments
* 3) Many audio packets.
*/
/* Use the path name of the id3 structure as a temporary buffer. */
unsigned char* buf = (unsigned char *)id3->path;
long comment_size;
long remaining = 0;
long last_serial = 0;
long serial, r;
int segments, header_size;
int i;
bool eof = false;
/* 92 bytes is enough for both Vorbis and Speex headers */
if ((lseek(fd, 0, SEEK_SET) < 0) || (read(fd, buf, 92) < 92))
{
return false;
}
/* All Ogg streams start with OggS */
if (memcmp(buf, "OggS", 4) != 0)
{
return false;
}
/* Check for format magic and then get metadata */
if (memcmp(&buf[29], "vorbis", 6) == 0)
{
id3->codectype = AFMT_OGG_VORBIS;
id3->frequency = get_long_le(&buf[40]);
id3->vbr = true;
/* Comments are in second Ogg page (byte 58 onwards for Vorbis) */
if (lseek(fd, 58, SEEK_SET) < 0)
{
return false;
}
}
else if (memcmp(&buf[28], "Speex ", 8) == 0)
{
id3->codectype = AFMT_SPEEX;
id3->frequency = get_slong(&buf[64]);
id3->vbr = get_long_le(&buf[88]);
header_size = get_long_le(&buf[60]);
/* Comments are in second Ogg page (byte 108 onwards for Speex) */
if (lseek(fd, 28 + header_size, SEEK_SET) < 0)
{
return false;
}
}
else if (memcmp(&buf[28], "OpusHead", 8) == 0)
{
id3->codectype = AFMT_OPUS;
id3->frequency = 48000;
id3->vbr = true;
// FIXME handle an actual channel mapping table
/* Comments are in second Ogg page (byte 108 onwards for Speex) */
if (lseek(fd, 47, SEEK_SET) < 0)
{
DEBUGF("Couldnotseektoogg");
return false;
}
}
else
{
/* Unsupported format, try to print the marker, catches Ogg/FLAC at least */
DEBUGF("Usupported format in Ogg stream: %16s\n", &buf[28]);
return false;
}
id3->filesize = filesize(fd);
/* We need to ensure the serial number from this page is the same as the
* one from the last page (since we only support a single bitstream).
*/
serial = get_long_le(&buf[14]);
comment_size = read_vorbis_tags(fd, id3, remaining);
/* We now need to search for the last page in the file - identified by
* by ('O','g','g','S',0) and retrieve totalsamples.
*/
/* A page is always < 64 kB */
if (lseek(fd, -(MIN(64 * 1024, id3->filesize)), SEEK_END) < 0)
{
return false;
}
remaining = 0;
while (!eof)
{
r = read(fd, &buf[remaining], MAX_PATH - remaining);
if (r <= 0)
{
eof = true;
}
else
{
remaining += r;
}
/* Inefficient (but simple) search */
i = 0;
while (i < (remaining - 3))
{
if ((buf[i] == 'O') && (memcmp(&buf[i], "OggS", 4) == 0))
{
if (i < (remaining - 17))
{
/* Note that this only reads the low 32 bits of a
* 64 bit value.
*/
id3->samples = get_long_le(&buf[i + 6]);
last_serial = get_long_le(&buf[i + 14]);
/* If this page is very small the beginning of the next
* header could be in buffer. Jump near end of this header
* and continue */
i += 27;
}
else
{
break;
}
}
else
{
i++;
}
}
if (i < remaining)
{
/* Move the remaining bytes to start of buffer.
* Reuse var 'segments' as it is no longer needed */
segments = 0;
while (i < remaining)
{
buf[segments++] = buf[i++];
}
remaining = segments;
}
else
{
/* Discard the rest of the buffer */
remaining = 0;
}
}
/* This file has mutiple vorbis bitstreams (or is corrupt). */
/* FIXME we should display an error here. */
if (serial != last_serial)
{
logf("serialno mismatch");
logf("%ld", serial);
logf("%ld", last_serial);
return false;
}
id3->length = ((int64_t) id3->samples * 1000) / id3->frequency;
if (id3->length <= 0)
{
logf("ogg length invalid!");
return false;
}
id3->bitrate = (((int64_t) id3->filesize - comment_size) * 8) / id3->length;
return true;
}
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