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1 /*
2  * Copyright (C) 2016 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 ANDROID_HARDWARE_STREAM_HAL_INTERFACE_H
18 #define ANDROID_HARDWARE_STREAM_HAL_INTERFACE_H
19 
20 #include <media/audiohal/EffectHalInterface.h>
21 #include <system/audio.h>
22 #include <utils/Errors.h>
23 #include <utils/RefBase.h>
24 #include <utils/String8.h>
25 
26 namespace android {
27 
28 class StreamHalInterface : public virtual RefBase
29 {
30   public:
31     // Return the sampling rate in Hz - eg. 44100.
32     virtual status_t getSampleRate(uint32_t *rate) = 0;
33 
34     // Return size of input/output buffer in bytes for this stream - eg. 4800.
35     virtual status_t getBufferSize(size_t *size) = 0;
36 
37     // Return the channel mask.
38     virtual status_t getChannelMask(audio_channel_mask_t *mask) = 0;
39 
40     // Return the audio format - e.g. AUDIO_FORMAT_PCM_16_BIT.
41     virtual status_t getFormat(audio_format_t *format) = 0;
42 
43     // Convenience method.
44     virtual status_t getAudioProperties(
45             uint32_t *sampleRate, audio_channel_mask_t *mask, audio_format_t *format) = 0;
46 
47     // Set audio stream parameters.
48     virtual status_t setParameters(const String8& kvPairs) = 0;
49 
50     // Get audio stream parameters.
51     virtual status_t getParameters(const String8& keys, String8 *values) = 0;
52 
53     // Return the frame size (number of bytes per sample) of a stream.
54     virtual status_t getFrameSize(size_t *size) = 0;
55 
56     // Add or remove the effect on the stream.
57     virtual status_t addEffect(sp<EffectHalInterface> effect) = 0;
58     virtual status_t removeEffect(sp<EffectHalInterface> effect) = 0;
59 
60     // Put the audio hardware input/output into standby mode.
61     virtual status_t standby() = 0;
62 
63     virtual status_t dump(int fd) = 0;
64 
65     // Start a stream operating in mmap mode.
66     virtual status_t start() = 0;
67 
68     // Stop a stream operating in mmap mode.
69     virtual status_t stop() = 0;
70 
71     // Retrieve information on the data buffer in mmap mode.
72     virtual status_t createMmapBuffer(int32_t minSizeFrames,
73                                       struct audio_mmap_buffer_info *info) = 0;
74 
75     // Get current read/write position in the mmap buffer
76     virtual status_t getMmapPosition(struct audio_mmap_position *position) = 0;
77 
78     // Set the priority of the thread that interacts with the HAL
79     // (must match the priority of the audioflinger's thread that calls 'read' / 'write')
80     virtual status_t setHalThreadPriority(int priority) = 0;
81 
82   protected:
83     // Subclasses can not be constructed directly by clients.
StreamHalInterface()84     StreamHalInterface() {}
85 
86     // The destructor automatically closes the stream.
~StreamHalInterface()87     virtual ~StreamHalInterface() {}
88 };
89 
90 class StreamOutHalInterfaceCallback : public virtual RefBase {
91   public:
onWriteReady()92     virtual void onWriteReady() {}
onDrainReady()93     virtual void onDrainReady() {}
onError()94     virtual void onError() {}
95 
96   protected:
StreamOutHalInterfaceCallback()97     StreamOutHalInterfaceCallback() {}
~StreamOutHalInterfaceCallback()98     virtual ~StreamOutHalInterfaceCallback() {}
99 };
100 
101 class StreamOutHalInterface : public virtual StreamHalInterface {
102   public:
103     // Return the audio hardware driver estimated latency in milliseconds.
104     virtual status_t getLatency(uint32_t *latency) = 0;
105 
106     // Use this method in situations where audio mixing is done in the hardware.
107     virtual status_t setVolume(float left, float right) = 0;
108 
109     // Write audio buffer to driver.
110     virtual status_t write(const void *buffer, size_t bytes, size_t *written) = 0;
111 
112     // Return the number of audio frames written by the audio dsp to DAC since
113     // the output has exited standby.
114     virtual status_t getRenderPosition(uint32_t *dspFrames) = 0;
115 
116     // Get the local time at which the next write to the audio driver will be presented.
117     virtual status_t getNextWriteTimestamp(int64_t *timestamp) = 0;
118 
119     // Set the callback for notifying completion of non-blocking write and drain.
120     // The callback must be owned by someone else. The output stream does not own it
121     // to avoid strong pointer loops.
122     virtual status_t setCallback(wp<StreamOutHalInterfaceCallback> callback) = 0;
123 
124     // Returns whether pause and resume operations are supported.
125     virtual status_t supportsPauseAndResume(bool *supportsPause, bool *supportsResume) = 0;
126 
127     // Notifies to the audio driver to resume playback following a pause.
128     virtual status_t pause() = 0;
129 
130     // Notifies to the audio driver to resume playback following a pause.
131     virtual status_t resume() = 0;
132 
133     // Returns whether drain operation is supported.
134     virtual status_t supportsDrain(bool *supportsDrain) = 0;
135 
136     // Requests notification when data buffered by the driver/hardware has been played.
137     virtual status_t drain(bool earlyNotify) = 0;
138 
139     // Notifies to the audio driver to flush the queued data.
140     virtual status_t flush() = 0;
141 
142     // Return a recent count of the number of audio frames presented to an external observer.
143     virtual status_t getPresentationPosition(uint64_t *frames, struct timespec *timestamp) = 0;
144 
145   protected:
~StreamOutHalInterface()146     virtual ~StreamOutHalInterface() {}
147 };
148 
149 class StreamInHalInterface : public virtual StreamHalInterface {
150   public:
151     // Set the input gain for the audio driver.
152     virtual status_t setGain(float gain) = 0;
153 
154     // Read audio buffer in from driver.
155     virtual status_t read(void *buffer, size_t bytes, size_t *read) = 0;
156 
157     // Return the amount of input frames lost in the audio driver.
158     virtual status_t getInputFramesLost(uint32_t *framesLost) = 0;
159 
160     // Return a recent count of the number of audio frames received and
161     // the clock time associated with that frame count.
162     virtual status_t getCapturePosition(int64_t *frames, int64_t *time) = 0;
163 
164   protected:
~StreamInHalInterface()165     virtual ~StreamInHalInterface() {}
166 };
167 
168 } // namespace android
169 
170 #endif // ANDROID_HARDWARE_STREAM_HAL_INTERFACE_H
171