ladybird/Userland/Libraries/LibRIFF/Details.h
kleines Filmröllchen 64598473cc LibRIFF: Rework to match LibGfx needs
There's now two namespaces, RIFF (little-endian) and IFF (big-endian)
which (for the most part) contain the same kinds of structures for
handling similar data in both formats. (They also share almost all of
their implementation) The main types are ChunkHeader and (Owned)Chunk.
While Chunk has no ownership over the data it accesses (and can only be
constructed from a byte view), OwnedChunk has ownership over this data
and is aimed at reading from streams.

OwnedList, implementing the standard RIFF LIST type, is currently only
implemented for RIFF due to its only user being WAV, but it may be
generalized in the future for use by IFF.

Co-authored-by: Timothy Flynn <trflynn89@pm.me>
2024-01-15 23:23:26 -07:00

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C++

/*
* Copyright (c) 2023, kleines Filmröllchen <filmroellchen@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/ByteBuffer.h>
#include <AK/MemoryStream.h>
#include <LibRIFF/ChunkID.h>
// Despite the name, this header contains details for both RIFF and IFF
namespace RIFF::Detail {
// http://www-mmsp.ece.mcgill.ca/Documents/AudioFormats/WAVE/Docs/riffmci.pdf page 11 (Chunks)
template<typename WordType>
struct ChunkHeader {
static ErrorOr<ChunkHeader> read_from_stream(Stream& stream);
RIFF::ChunkID id;
u32 size;
};
// Standard RIFF/IFF file formats use a global chunk with a chunk ID (magic bytes) such as "RIFF" or "FORM".
// A chunk ID right at the start of the global chunk specifies the subformat specific to the file type.
// Example for RIFF from WebP: https://developers.google.com/speed/webp/docs/riff_container#webp_file_header
template<typename HeaderType>
struct FileHeader {
HeaderType global_header;
RIFF::ChunkID subformat;
static ErrorOr<FileHeader> read_from_stream(Stream& stream);
constexpr ChunkID magic() const { return global_header.id; }
constexpr u32 file_size() const { return global_header.size; }
};
// An RIFF or IFF chunk.
template<typename HeaderType>
class Chunk {
public:
Chunk(HeaderType header, ReadonlyBytes data);
// Note that the resulting chunk will refer to the provided data.
static ErrorOr<Chunk> decode(ReadonlyBytes data);
static ErrorOr<Chunk> decode_and_advance(ReadonlyBytes& data);
RIFF::ChunkID id() const { return m_header.id; }
u32 size() const { return m_header.size; }
ReadonlyBytes data() const { return m_data; }
FixedMemoryStream data_stream() const;
u8 operator[](size_t index) const { return data()[index]; }
private:
HeaderType m_header;
ReadonlyBytes m_data;
};
// Owns the chunk data and can therefore be parsed from a stream.
template<typename HeaderType>
class OwnedChunk : public Chunk<HeaderType> {
public:
using Buffer = AK::Detail::ByteBuffer<0>;
OwnedChunk(HeaderType, Buffer);
static ErrorOr<OwnedChunk> read_from_stream(Stream& stream);
private:
Buffer m_backing_data;
};
}