1 | /* |
2 | Copyright 2018 Google Inc. All Rights Reserved. |
3 | |
4 | Licensed under the Apache License, Version 2.0 (the "License"); |
5 | you may not use this file except in compliance with the License. |
6 | You may obtain a copy of the License at |
7 | |
8 | http://www.apache.org/licenses/LICENSE-2.0 |
9 | |
10 | Unless required by applicable law or agreed to in writing, software |
11 | distributed under the License is distributed on an "AS-IS" BASIS, |
12 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
13 | See the License for the specific language governing permissions and |
14 | limitations under the License. |
15 | */ |
16 | |
17 | #ifndef RESONANCE_AUDIO_UTILS_WAV_READER_H_ |
18 | #define RESONANCE_AUDIO_UTILS_WAV_READER_H_ |
19 | |
20 | #include <cstdint> |
21 | #include <istream> |
22 | |
23 | #include "base/integral_types.h" |
24 | |
25 | namespace vraudio { |
26 | |
27 | // Basic RIFF WAVE decoder that supports multichannel 16-bit PCM. |
28 | class WavReader { |
29 | public: |
30 | // Constructor decodes WAV header. |
31 | // |
32 | // @param binary_stream Binary input stream to read from. |
33 | explicit WavReader(std::istream* binary_stream); |
34 | |
35 | // True if WAV header was successfully parsed. |
36 | bool () const; |
37 | |
38 | // Returns the total number of samples defined in the WAV header. Note that |
39 | // the actual number of samples in the file can differ. |
40 | size_t GetNumTotalSamples() const; |
41 | |
42 | // Returns number of channels. |
43 | size_t GetNumChannels() const; |
44 | |
45 | // Returns sample rate in Hertz. |
46 | int GetSampleRateHz() const; |
47 | |
48 | // Seek to a specific frame position within the wave file. If frame_position |
49 | // is not a valid address, then the internal read position remains unchanged. |
50 | // |
51 | // @param frame_position Destination frame position for play cursor. |
52 | // @return Actual frame position of cursor after this seek operation. A |
53 | // negative return value indicates a stream failure. |
54 | int64 SeekToFrame(const uint64 frame_position); |
55 | |
56 | // Reads samples from WAV file into target buffer. |
57 | // |
58 | // @param num_samples Number of samples to read. |
59 | // @param target_buffer Target buffer to write to. |
60 | // @return Number of decoded samples. |
61 | size_t ReadSamples(size_t num_samples, int16_t* target_buffer); |
62 | |
63 | private: |
64 | // Parses WAV header. |
65 | // |
66 | // @return True on success. |
67 | bool (); |
68 | |
69 | // Helper method to read binary data from input stream. |
70 | // |
71 | // @param size Number of bytes to read. |
72 | // @param target_ptr Target buffer to write to. |
73 | // @return Number of bytes read. |
74 | size_t ReadBinaryDataFromStream(void* target_ptr, size_t size); |
75 | |
76 | // Binary input stream. |
77 | std::istream* binary_stream_; |
78 | |
79 | // Flag indicating if the WAV header was parsed successfully. |
80 | bool init_; |
81 | |
82 | // Number of audio channels. |
83 | size_t num_channels_; |
84 | |
85 | // Sample rate in Hertz. |
86 | int sample_rate_hz_; |
87 | |
88 | // Total number of samples. |
89 | size_t num_total_samples_; |
90 | |
91 | // Number of remaining samples in WAV file. |
92 | size_t num_remaining_samples_; |
93 | |
94 | // Bytes per sample as defined in the WAV header. |
95 | size_t bytes_per_sample_; |
96 | |
97 | // Offset into data stream where PCM data begins. |
98 | uint64 pcm_offset_bytes_; |
99 | }; |
100 | |
101 | } // namespace vraudio |
102 | |
103 | #endif // RESONANCE_AUDIO_UTILS_WAV_READER_H_ |
104 | |