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_BUFFER_UNPARTITIONER_H_ |
18 | #define RESONANCE_AUDIO_UTILS_BUFFER_UNPARTITIONER_H_ |
19 | |
20 | #include <functional> |
21 | #include <memory> |
22 | |
23 | #include "base/audio_buffer.h" |
24 | #include "base/logging.h" |
25 | |
26 | namespace vraudio { |
27 | |
28 | // Unpackages |AudioBuffer| into output buffers of arbitrary sizes. |
29 | class BufferUnpartitioner { |
30 | public: |
31 | // Callback to obtain input |AudioBuffer|s. Returns a nullptr if no buffers |
32 | // are available. |
33 | typedef std::function<const AudioBuffer*()> GetBufferCallback; |
34 | |
35 | // Constructor. |
36 | // |
37 | // @param num_channels Number of audio channels in input and output buffers. |
38 | // @param frames_per_buffer Number of frames per input buffer. |
39 | // @param buffer_callback Callback to receive output |AudioBuffer|s. |
40 | BufferUnpartitioner(size_t num_channels, size_t frames_per_buffer, |
41 | GetBufferCallback buffer_callback); |
42 | |
43 | // Returns the number of input buffers required for a given number of output |
44 | // frames and based on the current fill state of the internal |temp_buffer_|. |
45 | // |
46 | // @param num_output_frames Number of output frames. |
47 | // @return Number of required input |AudioBuffer|s. |
48 | size_t GetNumBuffersRequestedForNumInputFrames( |
49 | size_t num_output_frames) const; |
50 | |
51 | // Returns the number of buffered frames in internal |temp_buffer_|. |
52 | size_t GetNumBufferedFrames() const; |
53 | |
54 | // Requests an interleaved int16 output buffer. This method triggers |
55 | // |GetBufferCallback|. |
56 | // |
57 | // @param output_buffer Interleaved output buffer to write to. |
58 | // @param num_channels Number of channels in output buffer. |
59 | // @param num_frames Number of frames in output buffer. |
60 | // @return Number of frames actually written. |
61 | size_t GetBuffer(int16* output_buffer, size_t num_channels, |
62 | size_t num_frames); |
63 | |
64 | // Requests an interleaved float output buffer. This method triggers |
65 | // |GetBufferCallback|. |
66 | // |
67 | // @param output_buffer Interleaved output buffer to write to. |
68 | // @param num_channels Number of channels in output buffer. |
69 | // @param num_frames Number of frames in output buffer. |
70 | // @return Number of frames actually written. |
71 | size_t GetBuffer(float* output_buffer, size_t num_channels, |
72 | size_t num_frames); |
73 | |
74 | // Requests a planar int16 output buffer. This method triggers |
75 | // |GetBufferCallback|. |
76 | // |
77 | // @param output_buffer Planar output buffer to write to. |
78 | // @param num_channels Number of channels in output buffer. |
79 | // @param num_frames Number of frames in output buffer. |
80 | // @return Number of frames actually written. |
81 | size_t GetBuffer(int16** output_buffer, size_t num_channels, |
82 | size_t num_frames); |
83 | |
84 | // Requests a planar float output buffer. This method triggers |
85 | // |GetBufferCallback|. |
86 | // |
87 | // @param output_buffer Planar output buffer to write to. |
88 | // @param num_channels Number of channels in output buffer. |
89 | // @param num_frames Number of frames in output buffer. |
90 | // @return Number of frames actually written. |
91 | size_t GetBuffer(float** output_buffer, size_t num_channels, |
92 | size_t num_frames); |
93 | |
94 | // Clears internal temporary buffer that holds remaining audio frames. |
95 | void Clear(); |
96 | |
97 | private: |
98 | // Returns the number of frames that are buffered in |current_input_buffer_|. |
99 | // |
100 | // @return Number of frames in |current_input_buffer_|. If |
101 | // |current_input_buffer_| is undefined, it returns 0. |
102 | size_t GetNumFramesAvailableInBuffer() const; |
103 | |
104 | // Writes output buffer into target buffer. Supported buffer types are planar |
105 | // and interleaved floating point abd interleaved int16 output. This method |
106 | // triggers |GetBufferCallback|. |
107 | // |
108 | // @tparam BufferType Output buffer type. |
109 | // @param buffer Output buffer to write to. |
110 | // @param num_channels Number of channels in output buffer. |
111 | // @param num_frames Number of frames in output buffer. |
112 | // @return Number of frames actually written. |
113 | template <typename BufferType> |
114 | size_t GetBufferTemplated(BufferType buffer, size_t num_channels, |
115 | size_t num_frames); |
116 | |
117 | // Number of channels in output buffers. |
118 | const size_t num_channels_; |
119 | |
120 | // Number of frames per buffer in output buffers. |
121 | const size_t frames_per_buffer_; |
122 | |
123 | // Callback to request input |AudioBuffer|s. |
124 | const GetBufferCallback buffer_callback_; |
125 | |
126 | // Temporary buffer containing remaining audio frames. |
127 | const AudioBuffer* current_input_buffer_; // Not owned. |
128 | |
129 | // Current read position in |current_input_buffer_|. |
130 | size_t current_buffer_read_offset_frames_; |
131 | }; |
132 | |
133 | } // namespace vraudio |
134 | |
135 | #endif // RESONANCE_AUDIO_UTILS_BUFFER_UNPARTITIONER_H_ |
136 | |