1/*
2 Simple DirectMedia Layer
3 Copyright (C) 1997-2025 Sam Lantinga <slouken@libsdl.org>
4
5 This software is provided 'as-is', without any express or implied
6 warranty. In no event will the authors be held liable for any damages
7 arising from the use of this software.
8
9 Permission is granted to anyone to use this software for any purpose,
10 including commercial applications, and to alter it and redistribute it
11 freely, subject to the following restrictions:
12
13 1. The origin of this software must not be misrepresented; you must not
14 claim that you wrote the original software. If you use this software
15 in a product, an acknowledgment in the product documentation would be
16 appreciated but is not required.
17 2. Altered source versions must be plainly marked as such, and must not be
18 misrepresented as being the original software.
19 3. This notice may not be removed or altered from any source distribution.
20*/
21#include "SDL_internal.h"
22
23// RIFF WAVE files are little-endian
24
25/*******************************************/
26// Define values for Microsoft WAVE format
27/*******************************************/
28// FOURCC
29#define RIFF 0x46464952 // "RIFF"
30#define WAVE 0x45564157 // "WAVE"
31#define FACT 0x74636166 // "fact"
32#define LIST 0x5453494c // "LIST"
33#define BEXT 0x74786562 // "bext"
34#define JUNK 0x4B4E554A // "JUNK"
35#define FMT 0x20746D66 // "fmt "
36#define DATA 0x61746164 // "data"
37// Format tags
38#define UNKNOWN_CODE 0x0000
39#define PCM_CODE 0x0001
40#define MS_ADPCM_CODE 0x0002
41#define IEEE_FLOAT_CODE 0x0003
42#define ALAW_CODE 0x0006
43#define MULAW_CODE 0x0007
44#define IMA_ADPCM_CODE 0x0011
45#define MPEG_CODE 0x0050
46#define MPEGLAYER3_CODE 0x0055
47#define EXTENSIBLE_CODE 0xFFFE
48
49// Stores the WAVE format information.
50typedef struct WaveFormat
51{
52 Uint16 formattag; // Raw value of the first field in the fmt chunk data.
53 Uint16 encoding; // Actual encoding, possibly from the extensible header.
54 Uint16 channels; // Number of channels.
55 Uint32 frequency; // Sampling rate in Hz.
56 Uint32 byterate; // Average bytes per second.
57 Uint16 blockalign; // Bytes per block.
58 Uint16 bitspersample; // Currently supported are 8, 16, 24, 32, and 4 for ADPCM.
59
60 /* Extra information size. Number of extra bytes starting at byte 18 in the
61 * fmt chunk data. This is at least 22 for the extensible header.
62 */
63 Uint16 extsize;
64
65 // Extensible WAVE header fields
66 Uint16 validsamplebits;
67 Uint32 samplesperblock; // For compressed formats. Can be zero. Actually 16 bits in the header.
68 Uint32 channelmask;
69 Uint8 subformat[16]; // A format GUID.
70} WaveFormat;
71
72// Stores information on the fact chunk.
73typedef struct WaveFact
74{
75 /* Represents the state of the fact chunk in the WAVE file.
76 * Set to -1 if the fact chunk is invalid.
77 * Set to 0 if the fact chunk is not present
78 * Set to 1 if the fact chunk is present and valid.
79 * Set to 2 if samplelength is going to be used as the number of sample frames.
80 */
81 Sint32 status;
82
83 /* Version 1 of the RIFF specification calls the field in the fact chunk
84 * dwFileSize. The Standards Update then calls it dwSampleLength and specifies
85 * that it is 'the length of the data in samples'. WAVE files from Windows
86 * with this chunk have it set to the samples per channel (sample frames).
87 * This is useful to truncate compressed audio to a specific sample count
88 * because a compressed block is usually decoded to a fixed number of
89 * sample frames.
90 */
91 Uint32 samplelength; // Raw sample length value from the fact chunk.
92} WaveFact;
93
94// Generic struct for the chunks in the WAVE file.
95typedef struct WaveChunk
96{
97 Uint32 fourcc; // FOURCC of the chunk.
98 Uint32 length; // Size of the chunk data.
99 Sint64 position; // Position of the data in the stream.
100 Uint8 *data; // When allocated, this points to the chunk data. length is used for the memory allocation size.
101 size_t size; // Number of bytes in data that could be read from the stream. Can be smaller than length.
102} WaveChunk;
103
104// Controls how the size of the RIFF chunk affects the loading of a WAVE file.
105typedef enum WaveRiffSizeHint
106{
107 RiffSizeNoHint,
108 RiffSizeForce,
109 RiffSizeIgnoreZero,
110 RiffSizeIgnore,
111 RiffSizeMaximum
112} WaveRiffSizeHint;
113
114// Controls how a truncated WAVE file is handled.
115typedef enum WaveTruncationHint
116{
117 TruncNoHint,
118 TruncVeryStrict,
119 TruncStrict,
120 TruncDropFrame,
121 TruncDropBlock
122} WaveTruncationHint;
123
124// Controls how the fact chunk affects the loading of a WAVE file.
125typedef enum WaveFactChunkHint
126{
127 FactNoHint,
128 FactTruncate,
129 FactStrict,
130 FactIgnoreZero,
131 FactIgnore
132} WaveFactChunkHint;
133
134typedef struct WaveFile
135{
136 WaveChunk chunk;
137 WaveFormat format;
138 WaveFact fact;
139
140 /* Number of sample frames that will be decoded. Calculated either with the
141 * size of the data chunk or, if the appropriate hint is enabled, with the
142 * sample length value from the fact chunk.
143 */
144 Sint64 sampleframes;
145
146 void *decoderdata; // Some decoders require extra data for a state.
147
148 WaveRiffSizeHint riffhint;
149 WaveTruncationHint trunchint;
150 WaveFactChunkHint facthint;
151} WaveFile;
152