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/*
* Copyright (C) 2003-2013 The Music Player Daemon Project
* http://www.musicpd.org
*
* 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 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
/* \file
*
* This file contains functions used by the DSF and DSDIFF decoders.
*
*/
#include "config.h"
#include "DsdLib.hxx"
#include "DecoderAPI.hxx"
#include "InputStream.hxx"
#include "util/bit_reverse.h"
#include "tag/TagHandler.hxx"
#include "tag/TagId3.hxx"
#include "util/Error.hxx"
#include <unistd.h>
#include <string.h>
#include <stdio.h> /* for SEEK_SET, SEEK_CUR */
#ifdef HAVE_ID3TAG
#include <id3tag.h>
#endif
bool
DsdId::Equals(const char *s) const
{
assert(s != nullptr);
assert(strlen(s) == sizeof(value));
return memcmp(value, s, sizeof(value)) == 0;
}
bool
dsdlib_read(Decoder *decoder, InputStream &is,
void *data, size_t length)
{
size_t nbytes = decoder_read(decoder, is, data, length);
return nbytes == length;
}
/**
* Skip the #input_stream to the specified offset.
*/
bool
dsdlib_skip_to(Decoder *decoder, InputStream &is,
int64_t offset)
{
if (is.IsSeekable())
return is.Seek(offset, SEEK_SET, IgnoreError());
if (is.GetOffset() > offset)
return false;
char buffer[8192];
while (is.GetOffset() < offset) {
size_t length = sizeof(buffer);
if (offset - is.GetOffset() < (int64_t)length)
length = offset - is.GetOffset();
size_t nbytes = decoder_read(decoder, is, buffer, length);
if (nbytes == 0)
return false;
}
assert(is.GetOffset() == offset);
return true;
}
/**
* Skip some bytes from the #input_stream.
*/
bool
dsdlib_skip(Decoder *decoder, InputStream &is,
int64_t delta)
{
assert(delta >= 0);
if (delta == 0)
return true;
if (is.IsSeekable())
return is.Seek(delta, SEEK_CUR, IgnoreError());
char buffer[8192];
while (delta > 0) {
size_t length = sizeof(buffer);
if ((int64_t)length > delta)
length = delta;
size_t nbytes = decoder_read(decoder, is, buffer, length);
if (nbytes == 0)
return false;
delta -= nbytes;
}
return true;
}
#ifdef HAVE_ID3TAG
void
dsdlib_tag_id3(InputStream &is,
const struct tag_handler *handler,
void *handler_ctx, int64_t tagoffset)
{
assert(tagoffset >= 0);
if (tagoffset == 0)
return;
if (!dsdlib_skip_to(nullptr, is, tagoffset))
return;
struct id3_tag *id3_tag = nullptr;
id3_length_t count;
/* Prevent broken files causing problems */
const auto size = is.GetSize();
const auto offset = is.GetOffset();
if (offset >= size)
return;
count = size - offset;
/* Check and limit id3 tag size to prevent a stack overflow */
if (count == 0 || count > 4096)
return;
id3_byte_t dsdid3[count];
id3_byte_t *dsdid3data;
dsdid3data = dsdid3;
if (!dsdlib_read(nullptr, is, dsdid3data, count))
return;
id3_tag = id3_tag_parse(dsdid3data, count);
if (id3_tag == nullptr)
return;
scan_id3_tag(id3_tag, handler, handler_ctx);
id3_tag_delete(id3_tag);
return;
}
#endif
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