AudioSource.h revision 46292fb347d72a314d985e34e5e3743d846cb9b6 
1/*
2 * Copyright (C) 2009 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 AUDIO_SOURCE_H_
18
19#define AUDIO_SOURCE_H_
20
21#include <media/AudioSystem.h>
22#include <media/stagefright/MediaSource.h>
23
24namespace android {
25
26class AudioRecord;
27struct MediaBufferGroup;
28
29struct AudioSource : public MediaSource {
30    // Note that the "channels" parameter is _not_ the number of channels,
31    // but a bitmask of AudioSystem::audio_channels constants.
32    AudioSource(
33            int inputSource, uint32_t sampleRate,
34            uint32_t channels = AudioSystem::CHANNEL_IN_MONO);
35
36    status_t initCheck() const;
37
38    virtual status_t start(MetaData *params = NULL);
39    virtual status_t stop();
40    virtual sp<MetaData> getFormat();
41
42    // Returns the maximum amplitude since last call.
43    int16_t getMaxAmplitude();
44
45    virtual status_t read(
46            MediaBuffer **buffer, const ReadOptions *options = NULL);
47
48protected:
49    virtual ~AudioSource();
50
51private:
52    enum { kMaxBufferSize = 2048 };
53
54    AudioRecord *mRecord;
55    status_t mInitCheck;
56    bool mStarted;
57
58    bool mCollectStats;
59    bool mTrackMaxAmplitude;
60    int64_t mStartTimeUs;
61    int16_t mMaxAmplitude;
62    int64_t mPrevSampleTimeUs;
63    int64_t mNumLostFrames;
64
65    MediaBufferGroup *mGroup;
66
67    void trackMaxAmplitude(int16_t *data, int nSamples);
68
69    AudioSource(const AudioSource &);
70    AudioSource &operator=(const AudioSource &);
71};
72
73}  // namespace android
74
75#endif  // AUDIO_SOURCE_H_
76