AudioStreamOutSink.h revision 767094dd98b01baf21de2ad09c27b3c98776cf73 
1/*
2 * Copyright (C) 2012 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_AUDIO_STREAM_OUT_SINK_H
18#define ANDROID_AUDIO_STREAM_OUT_SINK_H
19
20#include <hardware/audio.h>
21#include "NBAIO.h"
22
23namespace android {
24
25// not multi-thread safe
26class AudioStreamOutSink : public NBAIO_Sink {
27
28public:
29    AudioStreamOutSink(audio_stream_out *stream);
30    virtual ~AudioStreamOutSink();
31
32    // NBAIO_Port interface
33
34    virtual ssize_t negotiate(const NBAIO_Format offers[], size_t numOffers,
35                              NBAIO_Format counterOffers[], size_t& numCounterOffers);
36    //virtual NBAIO_Format format();
37
38    // NBAIO_Sink interface
39
40    //virtual size_t framesWritten() const;
41    //virtual size_t framesUnderrun() const;
42    //virtual size_t underruns() const;
43
44    // This is an over-estimate, and could dupe the caller into making a blocking write()
45    // FIXME Use an audio HAL API to query the buffer emptying status when it's available.
46    virtual ssize_t availableToWrite() const { return mStreamBufferSizeBytes >> mBitShift; }
47
48    virtual ssize_t write(const void *buffer, size_t count);
49
50    // AudioStreamOutSink wraps a HAL's output stream.  Its
51    // getNextWriteTimestamp method is simply a passthru to the HAL's underlying
52    // implementation of GNWT (if any)
53    virtual status_t getNextWriteTimestamp(int64_t *timestamp);
54
55    virtual status_t getTimestamp(AudioTimestamp& timestamp);
56
57    // NBAIO_Sink end
58
59#if 0   // until necessary
60    audio_stream_out *stream() const { return mStream; }
61#endif
62
63private:
64    audio_stream_out * const mStream;
65    size_t              mStreamBufferSizeBytes; // as reported by get_buffer_size()
66};
67
68}   // namespace android
69
70#endif  // ANDROID_AUDIO_STREAM_OUT_SINK_H
71