1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
|
/*
* Copyright (C) 2012 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#define LOG_TAG "AudioBufferProviderSource"
//#define LOG_NDEBUG 0
#include <cutils/compiler.h>
#include <utils/Log.h>
#include <media/nbaio/AudioBufferProviderSource.h>
namespace android {
AudioBufferProviderSource::AudioBufferProviderSource(AudioBufferProvider *provider,
NBAIO_Format format) :
NBAIO_Source(format), mProvider(provider), mConsumed(0)
{
ALOG_ASSERT(provider != NULL);
ALOG_ASSERT(format != Format_Invalid);
}
AudioBufferProviderSource::~AudioBufferProviderSource()
{
if (mBuffer.raw != NULL) {
mProvider->releaseBuffer(&mBuffer);
}
}
ssize_t AudioBufferProviderSource::availableToRead()
{
if (CC_UNLIKELY(!mNegotiated)) {
return NEGOTIATE;
}
return mBuffer.raw != NULL ? mBuffer.frameCount - mConsumed : 0;
}
ssize_t AudioBufferProviderSource::read(void *buffer,
size_t count,
int64_t readPTS)
{
if (CC_UNLIKELY(!mNegotiated)) {
return NEGOTIATE;
}
if (CC_UNLIKELY(mBuffer.raw == NULL)) {
mBuffer.frameCount = count;
status_t status = mProvider->getNextBuffer(&mBuffer, readPTS);
if (status != OK) {
return status == NOT_ENOUGH_DATA ? (ssize_t) WOULD_BLOCK : (ssize_t) status;
}
ALOG_ASSERT(mBuffer.raw != NULL);
// mConsumed is 0 either from constructor or after releaseBuffer()
}
size_t available = mBuffer.frameCount - mConsumed;
if (CC_UNLIKELY(count > available)) {
count = available;
}
// count could be zero, either because count was zero on entry or
// available is zero, but both are unlikely so don't check for that
memcpy(buffer, (char *) mBuffer.raw + (mConsumed << mBitShift), count << mBitShift);
if (CC_UNLIKELY((mConsumed += count) >= mBuffer.frameCount)) {
mProvider->releaseBuffer(&mBuffer);
mBuffer.raw = NULL;
mConsumed = 0;
}
mFramesRead += count;
// For better responsiveness with large values of count,
// return a short count rather than continuing with next buffer.
// This gives the caller a chance to interpolate other actions.
return count;
}
ssize_t AudioBufferProviderSource::readVia(readVia_t via, size_t total, void *user,
int64_t readPTS, size_t block)
{
if (CC_UNLIKELY(!mNegotiated)) {
return NEGOTIATE;
}
if (CC_UNLIKELY(block == 0)) {
block = ~0;
}
for (size_t accumulator = 0; ; ) {
ALOG_ASSERT(accumulator <= total);
size_t count = total - accumulator;
if (CC_UNLIKELY(count == 0)) {
return accumulator;
}
if (CC_LIKELY(count > block)) {
count = block;
}
// 1 <= count <= block
if (CC_UNLIKELY(mBuffer.raw == NULL)) {
mBuffer.frameCount = count;
status_t status = mProvider->getNextBuffer(&mBuffer, readPTS);
if (CC_LIKELY(status == OK)) {
ALOG_ASSERT(mBuffer.raw != NULL && mBuffer.frameCount <= count);
// mConsumed is 0 either from constructor or after releaseBuffer()
continue;
}
// FIXME simplify logic - does the initial count and block checks again for no reason;
// don't you just want to fall through to the size_t available line?
if (CC_LIKELY(status == NOT_ENOUGH_DATA)) {
status = WOULD_BLOCK;
}
return accumulator > 0 ? accumulator : (ssize_t) status;
}
size_t available = mBuffer.frameCount - mConsumed;
if (CC_UNLIKELY(count > available)) {
count = available;
}
if (CC_LIKELY(count > 0)) {
char* readTgt = (char *) mBuffer.raw + (mConsumed << mBitShift);
ssize_t ret = via(user, readTgt, count, readPTS);
if (CC_UNLIKELY(ret <= 0)) {
if (CC_LIKELY(accumulator > 0)) {
return accumulator;
}
return ret;
}
ALOG_ASSERT((size_t) ret <= count);
mFramesRead += ret;
accumulator += ret;
if (CC_LIKELY((mConsumed += ret) < mBuffer.frameCount)) {
continue;
}
}
mProvider->releaseBuffer(&mBuffer);
mBuffer.raw = NULL;
mConsumed = 0;
// don't get next buffer until we really need it
}
}
} // namespace android
|
