51 lines
1.2 KiB
C++
51 lines
1.2 KiB
C++
// SPDX-License-Identifier: GPL-2.0-or-later
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// Copyright The Music Player Daemon Project
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#include "RiffId3.hxx"
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#include "RiffFormat.hxx"
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#include "input/InputStream.hxx"
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#include "util/ByteOrder.hxx"
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#include <limits>
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#include <stdexcept>
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#include <string.h>
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size_t
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riff_seek_id3(InputStream &is, std::unique_lock<Mutex> &lock)
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{
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/* seek to the beginning and read the RIFF header */
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is.Rewind(lock);
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RiffFileHeader header;
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is.ReadFull(lock, &header, sizeof(header));
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if (memcmp(header.id, "RIFF", 4) != 0 ||
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(is.KnownSize() && FromLE32(header.size) > is.GetSize()))
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throw std::runtime_error("Not a RIFF file");
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while (true) {
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/* read the chunk header */
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RiffChunkHeader chunk;
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is.ReadFull(lock, &chunk, sizeof(chunk));
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size_t size = FromLE32(chunk.size);
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if (size > size_t(std::numeric_limits<int>::max()))
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/* too dangerous, bail out: possible integer
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underflow when casting to off_t */
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throw std::runtime_error("RIFF chunk is too large");
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if (memcmp(chunk.id, "id3 ", 4) == 0 ||
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memcmp(chunk.id, "ID3 ", 4) == 0)
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/* found it! */
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return size;
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if (size % 2 != 0)
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/* pad byte */
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++size;
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is.Skip(lock, size);
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}
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}
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