1 /* Copyright 2018 The Chromium OS Authors. All rights reserved.
2 * Use of this source code is governed by a BSD-style license that can be
3 * found in the LICENSE file.
4 */
5
6 #ifndef FLOAT_BUFFER_H_
7 #define FLOAT_BUFFER_H_
8
9 #include "byte_buffer.h"
10
11 /*
12 * Circular buffer storing deinterleaved floating point data.
13 * Members:
14 * fp - Pointer to be filled wtih read/write position of the buffer.
15 * num_channels - Number of channels.
16 */
17 struct float_buffer {
18 struct byte_buffer *buf;
19 float **fp;
20 unsigned int num_channels;
21 };
22
23 /*
24 * Creates an float_buffer.
25 * Args:
26 * max_size - The max number of frames this buffer may store.
27 * num_channels - Number of channels of the deinterleaved data.
28 */
float_buffer_create(unsigned int max_size,unsigned int num_channels)29 static inline struct float_buffer *float_buffer_create(
30 unsigned int max_size,
31 unsigned int num_channels)
32 {
33 struct float_buffer *b;
34
35 b = (struct float_buffer *)calloc(1, sizeof(*b));
36
37 b->num_channels = num_channels;
38 b->fp = (float **)malloc(num_channels * sizeof(float *));
39 b->buf = (struct byte_buffer *)
40 calloc(1, sizeof(struct byte_buffer) +
41 max_size * num_channels * sizeof(float));
42 b->buf->max_size = max_size;
43 b->buf->used_size = max_size;
44 return b;
45 }
46
47 /* Destroys the float buffer. */
float_buffer_destroy(struct float_buffer ** b)48 static inline void float_buffer_destroy(struct float_buffer **b)
49 {
50 if (*b == NULL)
51 return;
52
53 byte_buffer_destroy(&(*b)->buf);
54 free((*b)->fp);
55 free(*b);
56 *b = NULL;
57 }
58
59 /* Gets the write pointer of given float_buffer. */
float_buffer_write_pointer(struct float_buffer * b)60 static inline float *const *float_buffer_write_pointer(struct float_buffer *b)
61 {
62 unsigned int i;
63 float *data = (float *)b->buf->bytes;
64
65 for (i = 0; i < b->num_channels; i++, data += b->buf->max_size)
66 b->fp[i] = data + b->buf->write_idx;
67 return b->fp;
68 }
69
70 /* Gets the number of frames can write to the float_buffer. */
float_buffer_writable(struct float_buffer * b)71 static inline unsigned int float_buffer_writable(struct float_buffer *b)
72 {
73 return buf_writable(b->buf);
74 }
75
76 /* Marks |nwritten| of frames as written to float_buffer. */
float_buffer_written(struct float_buffer * b,unsigned int nwritten)77 static inline void float_buffer_written(struct float_buffer *b,
78 unsigned int nwritten)
79 {
80 buf_increment_write(b->buf, nwritten);
81 }
82
83 /* Gets the read pointer of given float_buffer. */
float_buffer_read_pointer(struct float_buffer * b,unsigned int offset,unsigned int * readable)84 static inline float *const *float_buffer_read_pointer(struct float_buffer *b,
85 unsigned int offset,
86 unsigned int *readable)
87 {
88 unsigned int i;
89 float *data = (float *)b->buf->bytes;
90 unsigned int nread = buf_readable(b->buf);
91
92 if (offset >= buf_queued(b->buf)) {
93 *readable = 0;
94 offset = 0;
95 } else if (offset >= nread) {
96 /* wraps */
97 offset = offset + b->buf->read_idx - b->buf->max_size;
98 *readable = MIN(*readable, b->buf->write_idx - offset);
99 } else {
100 *readable = MIN(*readable, nread - offset);
101 offset += b->buf->read_idx;
102 }
103
104 for (i = 0; i < b->num_channels; i++, data += b->buf->max_size)
105 b->fp[i] = data + offset;
106 return b->fp;
107 }
108
109 /* Gets the buffer level in frames queued in float_buffer. */
float_buffer_level(struct float_buffer * b)110 static inline unsigned int float_buffer_level(struct float_buffer *b)
111 {
112 return buf_queued(b->buf);
113 }
114
115 /* Resets float_buffer to initial state. */
float_buffer_reset(struct float_buffer * b)116 static inline void float_buffer_reset(struct float_buffer *b)
117 {
118 buf_reset(b->buf);
119 }
120
121 /* Marks |nread| frames as read in float_buffer. */
float_buffer_read(struct float_buffer * b,unsigned int nread)122 static inline void float_buffer_read(struct float_buffer *b,
123 unsigned int nread)
124 {
125 buf_increment_read(b->buf, nread);
126 }
127
128 #endif /* FLOAT_BUFFER_H_ */
129