1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
|
/*
* Copyright (c) 2021, Arne Elster <arne@elster.li>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include "Loader.h"
#include "MP3Types.h"
#include <AK/BitStream.h>
#include <AK/MemoryStream.h>
#include <AK/Tuple.h>
#include <LibDSP/MDCT.h>
namespace Audio {
namespace MP3::Tables {
struct ScaleFactorBand;
}
class MP3LoaderPlugin : public LoaderPlugin {
public:
explicit MP3LoaderPlugin(NonnullOwnPtr<SeekableStream> stream);
virtual ~MP3LoaderPlugin() = default;
static Result<NonnullOwnPtr<MP3LoaderPlugin>, LoaderError> create(StringView path);
static Result<NonnullOwnPtr<MP3LoaderPlugin>, LoaderError> create(Bytes buffer);
virtual LoaderSamples get_more_samples(size_t max_bytes_to_read_from_input = 128 * KiB) override;
virtual MaybeLoaderError reset() override;
virtual MaybeLoaderError seek(int const position) override;
virtual int loaded_samples() override { return m_loaded_samples; }
virtual int total_samples() override { return m_total_samples; }
virtual u32 sample_rate() override { return m_sample_rate; }
virtual u16 num_channels() override { return m_num_channels; }
virtual PcmSampleFormat pcm_format() override { return m_sample_format; }
virtual DeprecatedString format_name() override { return "MP3 (.mp3)"; }
private:
MaybeLoaderError initialize();
MaybeLoaderError synchronize();
MaybeLoaderError build_seek_table();
ErrorOr<MP3::Header, LoaderError> read_header();
ErrorOr<MP3::MP3Frame, LoaderError> read_next_frame();
ErrorOr<MP3::MP3Frame, LoaderError> read_frame_data(MP3::Header const&);
MaybeLoaderError read_side_information(MP3::MP3Frame&);
ErrorOr<size_t, LoaderError> read_scale_factors(MP3::MP3Frame&, BigEndianInputBitStream& reservoir, size_t granule_index, size_t channel_index);
MaybeLoaderError read_huffman_data(MP3::MP3Frame&, BigEndianInputBitStream& reservoir, size_t granule_index, size_t channel_index, size_t granule_bits_read);
static AK::Array<float, 576> calculate_frame_exponents(MP3::MP3Frame const&, size_t granule_index, size_t channel_index);
static void reorder_samples(MP3::Granule&, u32 sample_rate);
static void reduce_alias(MP3::Granule&, size_t max_subband_index = 576);
static void process_stereo(MP3::MP3Frame&, size_t granule_index);
static void transform_samples_to_time(Array<float, 576> const& input, size_t input_offset, Array<float, 36>& output, MP3::BlockType block_type);
static void synthesis(Array<float, 1024>& V, Array<float, 32>& samples, Array<float, 32>& result);
static ReadonlySpan<MP3::Tables::ScaleFactorBand> get_scalefactor_bands(MP3::Granule const&, int samplerate);
AK::Vector<AK::Tuple<size_t, int>> m_seek_table;
AK::Array<AK::Array<AK::Array<float, 18>, 32>, 2> m_last_values {};
AK::Array<AK::Array<float, 1024>, 2> m_synthesis_buffer {};
static DSP::MDCT<36> s_mdct_36;
static DSP::MDCT<12> s_mdct_12;
u32 m_sample_rate { 0 };
u8 m_num_channels { 0 };
PcmSampleFormat m_sample_format { PcmSampleFormat::Int16 };
int m_total_samples { 0 };
size_t m_loaded_samples { 0 };
AK::Optional<MP3::MP3Frame> m_current_frame;
u32 m_current_frame_read;
OwnPtr<BigEndianInputBitStream> m_bitstream;
AllocatingMemoryStream m_bit_reservoir;
};
}
|
