NBAIO.h revision b5fc9e5454e606df9bed9ca81c1ab7f9317f8b54
1010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten/* 2010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten * Copyright (C) 2012 The Android Open Source Project 3010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten * 4010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten * Licensed under the Apache License, Version 2.0 (the "License"); 5010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten * you may not use this file except in compliance with the License. 6010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten * You may obtain a copy of the License at 7010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten * 8010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten * http://www.apache.org/licenses/LICENSE-2.0 9010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten * 10010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten * Unless required by applicable law or agreed to in writing, software 11010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten * distributed under the License is distributed on an "AS IS" BASIS, 12010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten * See the License for the specific language governing permissions and 14010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten * limitations under the License. 15010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten */ 16010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 17010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten#ifndef ANDROID_AUDIO_NBAIO_H 18010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten#define ANDROID_AUDIO_NBAIO_H 19010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 20010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten// Non-blocking audio I/O interface 21010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten// 22010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten// This header file has the abstract interfaces only. Concrete implementation classes are declared 23010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten// elsewhere. Implementations _should_ be non-blocking for all methods, especially read() and 24010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten// write(), but this is not enforced. In general, implementations do not need to be multi-thread 25010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten// safe, and any exceptions are noted in the particular implementation. 26010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 27010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten#include <limits.h> 28010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten#include <stdlib.h> 292c3b2da3049627264b7c6b449a1622f002210f03John Grossman#include <utils/Errors.h> 30010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten#include <utils/RefBase.h> 31767094dd98b01baf21de2ad09c27b3c98776cf73Glenn Kasten#include <media/AudioTimestamp.h> 32f95a3c4122d67273d930c7d83c3df99f136603edGlenn Kasten#include <system/audio.h> 33010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 34010662326b9c43c703725f933e95e0897f8a6bddGlenn Kastennamespace android { 35010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 36010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten// In addition to the usual status_t 37010662326b9c43c703725f933e95e0897f8a6bddGlenn Kastenenum { 381b291841a58ce6b2b291232dfdd56134b2185c48Glenn Kasten NEGOTIATE = (UNKNOWN_ERROR + 0x100), // Must (re-)negotiate format. For negotiate() only, 391b291841a58ce6b2b291232dfdd56134b2185c48Glenn Kasten // the offeree doesn't accept offers, and proposes 401b291841a58ce6b2b291232dfdd56134b2185c48Glenn Kasten // counter-offers 411b291841a58ce6b2b291232dfdd56134b2185c48Glenn Kasten OVERRUN = (UNKNOWN_ERROR + 0x101), // availableToRead(), read(), or readVia() detected 421b291841a58ce6b2b291232dfdd56134b2185c48Glenn Kasten // lost input due to overrun; an event is counted and 431b291841a58ce6b2b291232dfdd56134b2185c48Glenn Kasten // the caller should re-try 441b291841a58ce6b2b291232dfdd56134b2185c48Glenn Kasten UNDERRUN = (UNKNOWN_ERROR + 0x102), // availableToWrite(), write(), or writeVia() detected 451b291841a58ce6b2b291232dfdd56134b2185c48Glenn Kasten // a gap in output due to underrun (not being called 461b291841a58ce6b2b291232dfdd56134b2185c48Glenn Kasten // often enough, or with enough data); an event is 471b291841a58ce6b2b291232dfdd56134b2185c48Glenn Kasten // counted and the caller should re-try 48010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten}; 49010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 50010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten// Negotiation of format is based on the data provider and data sink, or the data consumer and 51010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten// data source, exchanging prioritized arrays of offers and counter-offers until a single offer is 52010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten// mutually agreed upon. Each offer is an NBAIO_Format. For simplicity and performance, 53b64497eb8724c4c372fffdbf3ee30543432953c5Glenn Kasten// NBAIO_Format is a typedef that ties together the most important combinations of the various 54010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten// attributes, rather than a struct with separate fields for format, sample rate, channel count, 55010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten// interleave, packing, alignment, etc. The reason is that NBAIO_Format tries to abstract out only 56b64497eb8724c4c372fffdbf3ee30543432953c5Glenn Kasten// the combinations that are actually needed within AudioFlinger. If the list of combinations grows 57010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten// too large, then this decision should be re-visited. 58b64497eb8724c4c372fffdbf3ee30543432953c5Glenn Kasten// Sample rate and channel count are explicit, PCM interleaved 16-bit is assumed. 59c4b8b32dec91a11a83d0a7ab49747606d16d39a5Glenn Kastenstruct NBAIO_Format { 6055e599daff7712142095f546b7e5bf2dcda807a8Glenn Kasten// FIXME make this a class, and change Format_... global methods to class methods 61c4b8b32dec91a11a83d0a7ab49747606d16d39a5Glenn Kasten//private: 622b7b910f4b417ab3930379298f538d0dfc857e88Glenn Kasten unsigned mSampleRate; 632b7b910f4b417ab3930379298f538d0dfc857e88Glenn Kasten unsigned mChannelCount; 642b7b910f4b417ab3930379298f538d0dfc857e88Glenn Kasten audio_format_t mFormat; 6555e599daff7712142095f546b7e5bf2dcda807a8Glenn Kasten size_t mFrameSize; 66c4b8b32dec91a11a83d0a7ab49747606d16d39a5Glenn Kasten}; 6751d53cd993043d9286e12cba884e6ee4d10b5facGlenn Kasten 6851d53cd993043d9286e12cba884e6ee4d10b5facGlenn Kastenextern const NBAIO_Format Format_Invalid; 69010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 70010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten// Return the frame size of an NBAIO_Format in bytes 7172e54af9fcdc4754914fe2bf8de699523538b315Glenn Kastensize_t Format_frameSize(const NBAIO_Format& format); 72010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 73010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten// Convert a sample rate in Hz and channel count to an NBAIO_Format 74f69f9869514730aebe5724c461768507084dfff7Glenn Kasten// FIXME rename 75f69f9869514730aebe5724c461768507084dfff7Glenn KastenNBAIO_Format Format_from_SR_C(unsigned sampleRate, unsigned channelCount, audio_format_t format); 76010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 77010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten// Return the sample rate in Hz of an NBAIO_Format 7872e54af9fcdc4754914fe2bf8de699523538b315Glenn Kastenunsigned Format_sampleRate(const NBAIO_Format& format); 79010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 80010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten// Return the channel count of an NBAIO_Format 8172e54af9fcdc4754914fe2bf8de699523538b315Glenn Kastenunsigned Format_channelCount(const NBAIO_Format& format); 82010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 83010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten// Callbacks used by NBAIO_Sink::writeVia() and NBAIO_Source::readVia() below. 84010662326b9c43c703725f933e95e0897f8a6bddGlenn Kastentypedef ssize_t (*writeVia_t)(void *user, void *buffer, size_t count); 85d79072e9dff59f767cce2cda1caab80ce5a0815bGlenn Kastentypedef ssize_t (*readVia_t)(void *user, const void *buffer, size_t count); 86010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 87cc1e0e807ee9a9f163a4685cbd6efd6ae55849cfGlenn Kasten// Check whether an NBAIO_Format is valid 88cc1e0e807ee9a9f163a4685cbd6efd6ae55849cfGlenn Kastenbool Format_isValid(const NBAIO_Format& format); 89cc1e0e807ee9a9f163a4685cbd6efd6ae55849cfGlenn Kasten 90cc1e0e807ee9a9f163a4685cbd6efd6ae55849cfGlenn Kasten// Compare two NBAIO_Format values 91cc1e0e807ee9a9f163a4685cbd6efd6ae55849cfGlenn Kastenbool Format_isEqual(const NBAIO_Format& format1, const NBAIO_Format& format2); 92cc1e0e807ee9a9f163a4685cbd6efd6ae55849cfGlenn Kasten 93010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten// Abstract class (interface) representing a data port. 94010662326b9c43c703725f933e95e0897f8a6bddGlenn Kastenclass NBAIO_Port : public RefBase { 95010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 96010662326b9c43c703725f933e95e0897f8a6bddGlenn Kastenpublic: 97010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 98010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // negotiate() must called first. The purpose of negotiate() is to check compatibility of 99010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // formats, not to automatically adapt if they are incompatible. It's the responsibility of 100010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // whoever sets up the graph connections to make sure formats are compatible, and this method 101010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // just verifies that. The edges are "dumb" and don't attempt to adapt to bad connections. 102010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // How it works: offerer proposes an array of formats, in descending order of preference from 103010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // offers[0] to offers[numOffers - 1]. If offeree accepts one of these formats, it returns 104010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // the index of that offer. Otherwise, offeree sets numCounterOffers to the number of 105010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // counter-offers (up to a maximumum of the entry value of numCounterOffers), fills in the 106010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // provided array counterOffers[] with its counter-offers, in descending order of preference 107010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // from counterOffers[0] to counterOffers[numCounterOffers - 1], and returns NEGOTIATE. 108010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Note that since the offerer allocates space for counter-offers, but only the offeree knows 109010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // how many counter-offers it has, there may be insufficient space for all counter-offers. 110010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // In that case, the offeree sets numCounterOffers to the requested number of counter-offers 111010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // (which is greater than the entry value of numCounterOffers), fills in as many of the most 112010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // important counterOffers as will fit, and returns NEGOTIATE. As this implies a re-allocation, 113010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // it should be used as a last resort. It is preferable for the offerer to simply allocate a 114010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // larger space to begin with, and/or for the offeree to tolerate a smaller space than desired. 115010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Alternatively, the offerer can pass NULL for offers and counterOffers, and zero for 116010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // numOffers. This indicates that it has not allocated space for any counter-offers yet. 117010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // In this case, the offerree should set numCounterOffers appropriately and return NEGOTIATE. 118010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Then the offerer will allocate the correct amount of memory and retry. 119010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Format_Invalid is not allowed as either an offer or counter-offer. 120010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Returns: 121010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // >= 0 Offer accepted. 122010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // NEGOTIATE No offer accepted, and counter-offer(s) optionally made. See above for details. 123010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten virtual ssize_t negotiate(const NBAIO_Format offers[], size_t numOffers, 124010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten NBAIO_Format counterOffers[], size_t& numCounterOffers); 125010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 126010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Return the current negotiated format, or Format_Invalid if negotiation has not been done, 127010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // or if re-negotiation is required. 128010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten virtual NBAIO_Format format() const { return mNegotiated ? mFormat : Format_Invalid; } 129010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 130010662326b9c43c703725f933e95e0897f8a6bddGlenn Kastenprotected: 13172e54af9fcdc4754914fe2bf8de699523538b315Glenn Kasten NBAIO_Port(const NBAIO_Format& format) : mNegotiated(false), mFormat(format), 132ac3e9db88ddb1f24bc6c8fb744a37dfdeec332bbGlenn Kasten mFrameSize(Format_frameSize(format)) { } 133010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten virtual ~NBAIO_Port() { } 134010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 135010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Implementations are free to ignore these if they don't need them 136010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 137010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten bool mNegotiated; // mNegotiated implies (mFormat != Format_Invalid) 138010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten NBAIO_Format mFormat; // (mFormat != Format_Invalid) does not imply mNegotiated 139ac3e9db88ddb1f24bc6c8fb744a37dfdeec332bbGlenn Kasten size_t mFrameSize; // assign in parallel with any assignment to mFormat 140010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten}; 141010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 142010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten// Abstract class (interface) representing a non-blocking data sink, for use by a data provider. 143010662326b9c43c703725f933e95e0897f8a6bddGlenn Kastenclass NBAIO_Sink : public NBAIO_Port { 144010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 145010662326b9c43c703725f933e95e0897f8a6bddGlenn Kastenpublic: 146010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 147010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // For the next two APIs: 148010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // 32 bits rolls over after 27 hours at 44.1 kHz; if that concerns you then poll periodically. 149010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 150010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Return the number of frames written successfully since construction. 151818e7a32ce3633980138aff2c2bfcc5158b3cfccAndy Hung virtual int64_t framesWritten() const { return mFramesWritten; } 152010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 153010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Number of frames lost due to underrun since construction. 154818e7a32ce3633980138aff2c2bfcc5158b3cfccAndy Hung virtual int64_t framesUnderrun() const { return 0; } 155010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 156010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Number of underruns since construction, where a set of contiguous lost frames is one event. 157818e7a32ce3633980138aff2c2bfcc5158b3cfccAndy Hung virtual int64_t underruns() const { return 0; } 158010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 159010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Estimate of number of frames that could be written successfully now without blocking. 160010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // When a write() is actually attempted, the implementation is permitted to return a smaller or 161010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // larger transfer count, however it will make a good faith effort to give an accurate estimate. 162010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Errors: 163010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // NEGOTIATE (Re-)negotiation is needed. 164010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // UNDERRUN write() has not been called frequently enough, or with enough frames to keep up. 165010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // An underrun event is counted, and the caller should re-try this operation. 166010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // WOULD_BLOCK Determining how many frames can be written without blocking would itself block. 167010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten virtual ssize_t availableToWrite() const { return SSIZE_MAX; } 168010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 169010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Transfer data to sink from single input buffer. Implies a copy. 170010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Inputs: 171010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // buffer Non-NULL buffer owned by provider. 172010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // count Maximum number of frames to transfer. 173010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Return value: 174010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // > 0 Number of frames successfully transferred prior to first error. 175010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // = 0 Count was zero. 176010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // < 0 status_t error occurred prior to the first frame transfer. 177010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Errors: 178010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // NEGOTIATE (Re-)negotiation is needed. 179010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // WOULD_BLOCK No frames can be transferred without blocking. 180010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // UNDERRUN write() has not been called frequently enough, or with enough frames to keep up. 181010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // An underrun event is counted, and the caller should re-try this operation. 182010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten virtual ssize_t write(const void *buffer, size_t count) = 0; 183010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 184010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Transfer data to sink using a series of callbacks. More suitable for zero-fill, synthesis, 185010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // and non-contiguous transfers (e.g. circular buffer or writev). 186010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Inputs: 187010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // via Callback function that the sink will call as many times as needed to consume data. 188010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // total Estimate of the number of frames the provider has available. This is an estimate, 189010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // and it can provide a different number of frames during the series of callbacks. 190010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // user Arbitrary void * reserved for data provider. 191010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // block Number of frames per block, that is a suggested value for 'count' in each callback. 192010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Zero means no preference. This parameter is a hint only, and may be ignored. 193010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Return value: 194010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // > 0 Total number of frames successfully transferred prior to first error. 195010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // = 0 Count was zero. 196010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // < 0 status_t error occurred prior to the first frame transfer. 197010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Errors: 198010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // NEGOTIATE (Re-)negotiation is needed. 199010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // WOULD_BLOCK No frames can be transferred without blocking. 200010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // UNDERRUN write() has not been called frequently enough, or with enough frames to keep up. 201010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // An underrun event is counted, and the caller should re-try this operation. 202010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // 203010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // The 'via' callback is called by the data sink as follows: 204010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Inputs: 205010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // user Arbitrary void * reserved for data provider. 206010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // buffer Non-NULL buffer owned by sink that callback should fill in with data, 207010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // up to a maximum of 'count' frames. 208010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // count Maximum number of frames to transfer during this callback. 209010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Return value: 210010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // > 0 Number of frames successfully transferred during this callback prior to first error. 211010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // = 0 Count was zero. 212010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // < 0 status_t error occurred prior to the first frame transfer during this callback. 213010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten virtual ssize_t writeVia(writeVia_t via, size_t total, void *user, size_t block = 0); 214010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 215767094dd98b01baf21de2ad09c27b3c98776cf73Glenn Kasten // Returns NO_ERROR if a timestamp is available. The timestamp includes the total number 216767094dd98b01baf21de2ad09c27b3c98776cf73Glenn Kasten // of frames presented to an external observer, together with the value of CLOCK_MONOTONIC 217200092b7f21d2b98f30b800e79d152636f9ba225Glenn Kasten // as of this presentation count. The timestamp parameter is undefined if error is returned. 218b5fc9e5454e606df9bed9ca81c1ab7f9317f8b54Dan Willemsen virtual status_t getTimestamp(ExtendedTimestamp& /*timestamp*/) { return INVALID_OPERATION; } 2192c3b2da3049627264b7c6b449a1622f002210f03John Grossman 220010662326b9c43c703725f933e95e0897f8a6bddGlenn Kastenprotected: 221b187de1ada34a9023c05d020a4592686ba761278Glenn Kasten NBAIO_Sink(const NBAIO_Format& format = Format_Invalid) : NBAIO_Port(format), mFramesWritten(0) 222b187de1ada34a9023c05d020a4592686ba761278Glenn Kasten { } 223010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten virtual ~NBAIO_Sink() { } 224010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 225010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Implementations are free to ignore these if they don't need them 226818e7a32ce3633980138aff2c2bfcc5158b3cfccAndy Hung int64_t mFramesWritten; 227010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten}; 228010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 229010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten// Abstract class (interface) representing a non-blocking data source, for use by a data consumer. 230010662326b9c43c703725f933e95e0897f8a6bddGlenn Kastenclass NBAIO_Source : public NBAIO_Port { 231010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 232010662326b9c43c703725f933e95e0897f8a6bddGlenn Kastenpublic: 233010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 234010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // For the next two APIs: 235010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // 32 bits rolls over after 27 hours at 44.1 kHz; if that concerns you then poll periodically. 236010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 237010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Number of frames read successfully since construction. 238818e7a32ce3633980138aff2c2bfcc5158b3cfccAndy Hung virtual int64_t framesRead() const { return mFramesRead; } 239010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 240010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Number of frames lost due to overrun since construction. 241010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Not const because implementations may need to do I/O. 242818e7a32ce3633980138aff2c2bfcc5158b3cfccAndy Hung virtual int64_t framesOverrun() /*const*/ { return 0; } 243010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 244010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Number of overruns since construction, where a set of contiguous lost frames is one event. 245010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Not const because implementations may need to do I/O. 246818e7a32ce3633980138aff2c2bfcc5158b3cfccAndy Hung virtual int64_t overruns() /*const*/ { return 0; } 247010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 248010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Estimate of number of frames that could be read successfully now. 249010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // When a read() is actually attempted, the implementation is permitted to return a smaller or 250010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // larger transfer count, however it will make a good faith effort to give an accurate estimate. 251010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Errors: 252010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // NEGOTIATE (Re-)negotiation is needed. 253010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // OVERRUN One or more frames were lost due to overrun, try again to read more recent data. 254010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // WOULD_BLOCK Determining how many frames can be read without blocking would itself block. 255010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten virtual ssize_t availableToRead() { return SSIZE_MAX; } 256010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 257010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Transfer data from source into single destination buffer. Implies a copy. 258010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Inputs: 259010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // buffer Non-NULL destination buffer owned by consumer. 260010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // count Maximum number of frames to transfer. 261010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Return value: 262010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // > 0 Number of frames successfully transferred prior to first error. 263010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // = 0 Count was zero. 264010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // < 0 status_t error occurred prior to the first frame transfer. 265010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Errors: 266010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // NEGOTIATE (Re-)negotiation is needed. 267010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // WOULD_BLOCK No frames can be transferred without blocking. 268010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // OVERRUN read() has not been called frequently enough, or with enough frames to keep up. 269010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // One or more frames were lost due to overrun, try again to read more recent data. 270d79072e9dff59f767cce2cda1caab80ce5a0815bGlenn Kasten virtual ssize_t read(void *buffer, size_t count) = 0; 271010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 272ad6d52d38917069e3d8e68cec1625855b9d96200Andy Hung // Flush data from buffer. There is no notion of overrun as all data is dropped. 273ad6d52d38917069e3d8e68cec1625855b9d96200Andy Hung // Flushed frames also count towards frames read. 274ad6d52d38917069e3d8e68cec1625855b9d96200Andy Hung // 275ad6d52d38917069e3d8e68cec1625855b9d96200Andy Hung // Return value: 276ad6d52d38917069e3d8e68cec1625855b9d96200Andy Hung // >= 0 Number of frames successfully flushed 277ad6d52d38917069e3d8e68cec1625855b9d96200Andy Hung // < 0 status_t error occurred 278ad6d52d38917069e3d8e68cec1625855b9d96200Andy Hung // Errors: 279ad6d52d38917069e3d8e68cec1625855b9d96200Andy Hung // NEGOTIATE (Re-)negotiation is needed. 280ad6d52d38917069e3d8e68cec1625855b9d96200Andy Hung // INVALID_OPERATION Not implemented 281ad6d52d38917069e3d8e68cec1625855b9d96200Andy Hung virtual ssize_t flush() { return INVALID_OPERATION; } 282ad6d52d38917069e3d8e68cec1625855b9d96200Andy Hung 283010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Transfer data from source using a series of callbacks. More suitable for zero-fill, 284010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // synthesis, and non-contiguous transfers (e.g. circular buffer or readv). 285010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Inputs: 286010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // via Callback function that the source will call as many times as needed to provide data. 287010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // total Estimate of the number of frames the consumer desires. This is an estimate, 288010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // and it can consume a different number of frames during the series of callbacks. 289010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // user Arbitrary void * reserved for data consumer. 290010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // block Number of frames per block, that is a suggested value for 'count' in each callback. 291010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Zero means no preference. This parameter is a hint only, and may be ignored. 292010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Return value: 293010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // > 0 Total number of frames successfully transferred prior to first error. 294010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // = 0 Count was zero. 295010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // < 0 status_t error occurred prior to the first frame transfer. 296010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Errors: 297010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // NEGOTIATE (Re-)negotiation is needed. 298010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // WOULD_BLOCK No frames can be transferred without blocking. 299010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // OVERRUN read() has not been called frequently enough, or with enough frames to keep up. 300010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // One or more frames were lost due to overrun, try again to read more recent data. 301010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // 302010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // The 'via' callback is called by the data source as follows: 303010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Inputs: 304010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // user Arbitrary void * reserved for data consumer. 305010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // dest Non-NULL buffer owned by source that callback should consume data from, 306010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // up to a maximum of 'count' frames. 307010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // count Maximum number of frames to transfer during this callback. 308010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Return value: 309010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // > 0 Number of frames successfully transferred during this callback prior to first error. 310010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // = 0 Count was zero. 311010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // < 0 status_t error occurred prior to the first frame transfer during this callback. 312d79072e9dff59f767cce2cda1caab80ce5a0815bGlenn Kasten virtual ssize_t readVia(readVia_t via, size_t total, void *user, size_t block = 0); 313010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 314894d6be4f9b4721c77a01919ecf03b27cec90cc9Glenn Kasten // Invoked asynchronously by corresponding sink when a new timestamp is available. 315894d6be4f9b4721c77a01919ecf03b27cec90cc9Glenn Kasten // Default implementation ignores the timestamp. 316b5fc9e5454e606df9bed9ca81c1ab7f9317f8b54Dan Willemsen virtual void onTimestamp(const ExtendedTimestamp& /*timestamp*/) { } 317894d6be4f9b4721c77a01919ecf03b27cec90cc9Glenn Kasten 318010662326b9c43c703725f933e95e0897f8a6bddGlenn Kastenprotected: 319b187de1ada34a9023c05d020a4592686ba761278Glenn Kasten NBAIO_Source(const NBAIO_Format& format = Format_Invalid) : NBAIO_Port(format), mFramesRead(0) 320b187de1ada34a9023c05d020a4592686ba761278Glenn Kasten { } 321010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten virtual ~NBAIO_Source() { } 322010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 323010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Implementations are free to ignore these if they don't need them 324818e7a32ce3633980138aff2c2bfcc5158b3cfccAndy Hung int64_t mFramesRead; 325010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten}; 326010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 327010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten} // namespace android 328010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 329010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten#endif // ANDROID_AUDIO_NBAIO_H 330