1 /*
2  * Copyright (C) 2014 The Android Open Source Project
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 /* This file contains shared utility functions to handle the tinyalsa
18  * implementation for Android internal audio, generally in the hardware layer.
19  * Some routines may log a fatal error on failure, as noted.
20  */
21 
22 #ifndef ANDROID_AUDIO_ALSAOPS_H
23 #define ANDROID_AUDIO_ALSAOPS_H
24 
25 #include <cutils/log.h>
26 #include <system/audio.h>
27 #include <tinyalsa/asoundlib.h>
28 
29 __BEGIN_DECLS
30 
31 /* Converts audio_format to pcm_format.
32  * Parameters:
33  *  format  the audio_format_t to convert
34  *
35  * Logs a fatal error if format is not a valid convertible audio_format_t.
36  */
pcm_format_from_audio_format(audio_format_t format)37 static inline enum pcm_format pcm_format_from_audio_format(audio_format_t format)
38 {
39     switch (format) {
40 #ifdef HAVE_BIG_ENDIAN
41     case AUDIO_FORMAT_PCM_16_BIT:
42         return PCM_FORMAT_S16_BE;
43     case AUDIO_FORMAT_PCM_24_BIT_PACKED:
44         return PCM_FORMAT_S24_3BE;
45     case AUDIO_FORMAT_PCM_32_BIT:
46         return PCM_FORMAT_S32_BE;
47     case AUDIO_FORMAT_PCM_8_24_BIT:
48         return PCM_FORMAT_S24_BE;
49 #else
50     case AUDIO_FORMAT_PCM_16_BIT:
51         return PCM_FORMAT_S16_LE;
52     case AUDIO_FORMAT_PCM_24_BIT_PACKED:
53         return PCM_FORMAT_S24_3LE;
54     case AUDIO_FORMAT_PCM_32_BIT:
55         return PCM_FORMAT_S32_LE;
56     case AUDIO_FORMAT_PCM_8_24_BIT:
57         return PCM_FORMAT_S24_LE;
58 #endif
59     case AUDIO_FORMAT_PCM_FLOAT:  /* there is no equivalent for float */
60     default:
61         LOG_ALWAYS_FATAL("pcm_format_from_audio_format: invalid audio format %#x", format);
62         return 0;
63     }
64 }
65 
66 /* Converts pcm_format to audio_format.
67  * Parameters:
68  *  format  the pcm_format to convert
69  *
70  * Logs a fatal error if format is not a valid convertible pcm_format.
71  */
audio_format_from_pcm_format(enum pcm_format format)72 static inline audio_format_t audio_format_from_pcm_format(enum pcm_format format)
73 {
74     switch (format) {
75 #ifdef HAVE_BIG_ENDIAN
76     case PCM_FORMAT_S16_BE:
77         return AUDIO_FORMAT_PCM_16_BIT;
78     case PCM_FORMAT_S24_3BE:
79         return AUDIO_FORMAT_PCM_24_BIT_PACKED;
80     case PCM_FORMAT_S24_BE:
81         return AUDIO_FORMAT_PCM_8_24_BIT;
82     case PCM_FORMAT_S32_BE:
83         return AUDIO_FORMAT_PCM_32_BIT;
84 #else
85     case PCM_FORMAT_S16_LE:
86         return AUDIO_FORMAT_PCM_16_BIT;
87     case PCM_FORMAT_S24_3LE:
88         return AUDIO_FORMAT_PCM_24_BIT_PACKED;
89     case PCM_FORMAT_S24_LE:
90         return AUDIO_FORMAT_PCM_8_24_BIT;
91     case PCM_FORMAT_S32_LE:
92         return AUDIO_FORMAT_PCM_32_BIT;
93 #endif
94     default:
95         LOG_ALWAYS_FATAL("audio_format_from_pcm_format: invalid pcm format %#x", format);
96         return 0;
97     }
98 }
99 
100 __END_DECLS
101 
102 #endif /* ANDROID_AUDIO_ALSAOPS_H */
103