Implement getFramesRead for OpenSL ES OUTPUT #89
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and getFramesWritten for OpenSL ES INPUT. Query position in milliseconds from OpenSL ES. Use MonotonicCounter to build 64-bit frame counter from 32-bit internal counter. Fixes Issue #81
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| int64_t mCounter64 = 0; |
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Maybe should be atomic.
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Atomicity isn't for free--there are costs on synchronizing CPU caches. Also, in update32 we seem to update both 32-bit and 64-bit counters in one transaction. This will require making the whole pair to be atomic.
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Is there an std::atomic way to do that or do you just mean to use a mutex?
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Make a struct and put it into std::atomic. Depending on different conditions it may use a mutex internally, you can check that with is_lock_free function: http://en.cppreference.com/w/cpp/atomic/atomic/is_lock_free
For two counters, it should usually be lock-free, unless it's a 32-bit ARM CPU and the fields alignment is wrong.
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Mikhail and I talked. The caller is only updating the internal data from one thread at a time. So I will document that this is not thread-safe and require caller to guarantee synchronization.
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| int64_t AudioInputStreamOpenSLES::getFramesWritten() const { | ||
| int64_t millis64 = mPositionMillis.get(); |
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Extract common function and call from OutputStream
| mPositionMillis.reset32(); // OpenSL ES resets its millisecond position when stopped. | ||
| int64_t framesWritten = getFramesWritten(); | ||
| if (framesWritten >= 0) { | ||
| setFramesRead(framesWritten); |
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This is supposed to prevent drift but does not seem to be working.
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Is no longer drifting.
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| * Copyright 2016 The Android Open Source Project | |||
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The code was written in 2016. I copied it from inside AAudio.
src/common/MonotonicCounter.h
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| * Round 64-bit counter up to a multiple of the period. | ||
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| * @param period might be, for example, a buffer capacity |
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Specify that it has to be a positive integer.
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| int64_t mCounter64 = 0; |
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Atomicity isn't for free--there are costs on synchronizing CPU caches. Also, in update32 we seem to update both 32-bit and 64-bit counters in one transaction. This will require making the whole pair to be atomic.
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| int64_t AudioStreamOpenSLES::getFramesProcessedByServer() const { | ||
| int64_t millis64 = mPositionMillis.get(); | ||
| int64_t framesRead = millis64 * getSampleRate() / kMillisPerSecond; |
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change to framesProcessed
and getFramesWritten for OpenSL ES INPUT.
Query position in milliseconds from OpenSL ES.
Use MonotonicCounter to build 64-bit frame counter from
32-bit internal counter.
Fixes Issue #81