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 
23 namespace android {
24 
25 // not multi-thread safe
26 class AudioStreamOutSink : public NBAIO_Sink {
27 
28 public:
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.
availableToWrite()46     virtual ssize_t availableToWrite() const { return mStreamBufferSizeBytes / mFrameSize; }
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 
63 private:
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