1 /*
2  * Copyright (C) 2018 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 #ifndef EXT_PCM_H
18 #define EXT_PCM_H
19 
20 #include <pthread.h>
21 
22 #include <cutils/hashmap.h>
23 #include <tinyalsa/asoundlib.h>
24 
25 // Holds up to 4KB buffer for each mixer pipeline, this value is arbitrary chosen
26 #define MIXER_BUFFER_SIZE (1024 * 4)
27 
28 struct ext_mixer_pipeline {
29   int16_t buffer[MIXER_BUFFER_SIZE];
30   unsigned int position;
31 };
32 
33 struct ext_pcm {
34   struct pcm *pcm;
35   pthread_mutex_t lock;
36   unsigned int ref_count;
37   pthread_mutex_t mixer_lock;
38   struct ext_mixer_pipeline mixer_pipeline;
39   pthread_t mixer_thread;
40   Hashmap *mixer_pipeline_map;
41 };
42 
43 struct ext_pcm *ext_pcm_open(unsigned int card, unsigned int device,
44                              unsigned int flags, struct pcm_config *config);
45 int ext_pcm_close(struct ext_pcm *ext_pcm);
46 int ext_pcm_is_ready(struct ext_pcm *ext_pcm);
47 int ext_pcm_write(struct ext_pcm *ext_pcm, const char *bus_address,
48                   const void *data, unsigned int count);
49 const char *ext_pcm_get_error(struct ext_pcm *ext_pcm);
50 unsigned int ext_pcm_frames_to_bytes(struct ext_pcm *ext_pcm,
51                                      unsigned int frames);
52 
53 #endif  // EXT_PCM_H
54