NBAIO.h revision 894d6be4f9b4721c77a01919ecf03b27cec90cc9
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> 32010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 33010662326b9c43c703725f933e95e0897f8a6bddGlenn Kastennamespace android { 34010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 35010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten// In addition to the usual status_t 36010662326b9c43c703725f933e95e0897f8a6bddGlenn Kastenenum { 37010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten NEGOTIATE = 0x80000010, // Must (re-)negotiate format. For negotiate() only, the offeree 38010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // doesn't accept offers, and proposes counter-offers 39010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten OVERRUN = 0x80000011, // availableToRead(), read(), or readVia() detected lost input due 40010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // to overrun; an event is counted and the caller should re-try 41010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten UNDERRUN = 0x80000012, // availableToWrite(), write(), or writeVia() detected a gap in 42010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // output due to underrun (not being called often enough, or with 43010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // enough data); an event is counted and the caller should re-try 44010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten}; 45010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 46010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten// Negotiation of format is based on the data provider and data sink, or the data consumer and 47010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten// data source, exchanging prioritized arrays of offers and counter-offers until a single offer is 48010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten// mutually agreed upon. Each offer is an NBAIO_Format. For simplicity and performance, 49b64497eb8724c4c372fffdbf3ee30543432953c5Glenn Kasten// NBAIO_Format is a typedef that ties together the most important combinations of the various 50010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten// attributes, rather than a struct with separate fields for format, sample rate, channel count, 51010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten// interleave, packing, alignment, etc. The reason is that NBAIO_Format tries to abstract out only 52b64497eb8724c4c372fffdbf3ee30543432953c5Glenn Kasten// the combinations that are actually needed within AudioFlinger. If the list of combinations grows 53010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten// too large, then this decision should be re-visited. 54b64497eb8724c4c372fffdbf3ee30543432953c5Glenn Kasten// Sample rate and channel count are explicit, PCM interleaved 16-bit is assumed. 55b64497eb8724c4c372fffdbf3ee30543432953c5Glenn Kastentypedef unsigned NBAIO_Format; 56b64497eb8724c4c372fffdbf3ee30543432953c5Glenn Kastenenum { 57b64497eb8724c4c372fffdbf3ee30543432953c5Glenn Kasten Format_Invalid 58010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten}; 59010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 60010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten// Return the frame size of an NBAIO_Format in bytes 61010662326b9c43c703725f933e95e0897f8a6bddGlenn Kastensize_t Format_frameSize(NBAIO_Format format); 62010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 63010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten// Return the frame size of an NBAIO_Format as a bit shift 64010662326b9c43c703725f933e95e0897f8a6bddGlenn Kastensize_t Format_frameBitShift(NBAIO_Format format); 65010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 66010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten// Convert a sample rate in Hz and channel count to an NBAIO_Format 67010662326b9c43c703725f933e95e0897f8a6bddGlenn KastenNBAIO_Format Format_from_SR_C(unsigned sampleRate, unsigned channelCount); 68010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 69010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten// Return the sample rate in Hz of an NBAIO_Format 70010662326b9c43c703725f933e95e0897f8a6bddGlenn Kastenunsigned Format_sampleRate(NBAIO_Format format); 71010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 72010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten// Return the channel count of an NBAIO_Format 73010662326b9c43c703725f933e95e0897f8a6bddGlenn Kastenunsigned Format_channelCount(NBAIO_Format format); 74010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 75010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten// Callbacks used by NBAIO_Sink::writeVia() and NBAIO_Source::readVia() below. 76010662326b9c43c703725f933e95e0897f8a6bddGlenn Kastentypedef ssize_t (*writeVia_t)(void *user, void *buffer, size_t count); 772c3b2da3049627264b7c6b449a1622f002210f03John Grossmantypedef ssize_t (*readVia_t)(void *user, const void *buffer, 782c3b2da3049627264b7c6b449a1622f002210f03John Grossman size_t count, int64_t readPTS); 79010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 80010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten// Abstract class (interface) representing a data port. 81010662326b9c43c703725f933e95e0897f8a6bddGlenn Kastenclass NBAIO_Port : public RefBase { 82010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 83010662326b9c43c703725f933e95e0897f8a6bddGlenn Kastenpublic: 84010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 85010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // negotiate() must called first. The purpose of negotiate() is to check compatibility of 86010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // formats, not to automatically adapt if they are incompatible. It's the responsibility of 87010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // whoever sets up the graph connections to make sure formats are compatible, and this method 88010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // just verifies that. The edges are "dumb" and don't attempt to adapt to bad connections. 89010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // How it works: offerer proposes an array of formats, in descending order of preference from 90010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // offers[0] to offers[numOffers - 1]. If offeree accepts one of these formats, it returns 91010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // the index of that offer. Otherwise, offeree sets numCounterOffers to the number of 92010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // counter-offers (up to a maximumum of the entry value of numCounterOffers), fills in the 93010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // provided array counterOffers[] with its counter-offers, in descending order of preference 94010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // from counterOffers[0] to counterOffers[numCounterOffers - 1], and returns NEGOTIATE. 95010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Note that since the offerer allocates space for counter-offers, but only the offeree knows 96010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // how many counter-offers it has, there may be insufficient space for all counter-offers. 97010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // In that case, the offeree sets numCounterOffers to the requested number of counter-offers 98010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // (which is greater than the entry value of numCounterOffers), fills in as many of the most 99010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // important counterOffers as will fit, and returns NEGOTIATE. As this implies a re-allocation, 100010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // it should be used as a last resort. It is preferable for the offerer to simply allocate a 101010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // larger space to begin with, and/or for the offeree to tolerate a smaller space than desired. 102010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Alternatively, the offerer can pass NULL for offers and counterOffers, and zero for 103010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // numOffers. This indicates that it has not allocated space for any counter-offers yet. 104010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // In this case, the offerree should set numCounterOffers appropriately and return NEGOTIATE. 105010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Then the offerer will allocate the correct amount of memory and retry. 106010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Format_Invalid is not allowed as either an offer or counter-offer. 107010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Returns: 108010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // >= 0 Offer accepted. 109010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // NEGOTIATE No offer accepted, and counter-offer(s) optionally made. See above for details. 110010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten virtual ssize_t negotiate(const NBAIO_Format offers[], size_t numOffers, 111010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten NBAIO_Format counterOffers[], size_t& numCounterOffers); 112010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 113010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Return the current negotiated format, or Format_Invalid if negotiation has not been done, 114010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // or if re-negotiation is required. 115010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten virtual NBAIO_Format format() const { return mNegotiated ? mFormat : Format_Invalid; } 116010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 117010662326b9c43c703725f933e95e0897f8a6bddGlenn Kastenprotected: 118010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten NBAIO_Port(NBAIO_Format format) : mNegotiated(false), mFormat(format), 119010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten mBitShift(Format_frameBitShift(format)) { } 120010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten virtual ~NBAIO_Port() { } 121010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 122010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Implementations are free to ignore these if they don't need them 123010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 124010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten bool mNegotiated; // mNegotiated implies (mFormat != Format_Invalid) 125010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten NBAIO_Format mFormat; // (mFormat != Format_Invalid) does not imply mNegotiated 126010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten size_t mBitShift; // assign in parallel with any assignment to mFormat 127010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten}; 128010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 129010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten// Abstract class (interface) representing a non-blocking data sink, for use by a data provider. 130010662326b9c43c703725f933e95e0897f8a6bddGlenn Kastenclass NBAIO_Sink : public NBAIO_Port { 131010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 132010662326b9c43c703725f933e95e0897f8a6bddGlenn Kastenpublic: 133010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 134010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // For the next two APIs: 135010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // 32 bits rolls over after 27 hours at 44.1 kHz; if that concerns you then poll periodically. 136010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 137010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Return the number of frames written successfully since construction. 138010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten virtual size_t framesWritten() const { return mFramesWritten; } 139010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 140010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Number of frames lost due to underrun since construction. 141010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten virtual size_t framesUnderrun() const { return 0; } 142010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 143010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Number of underruns since construction, where a set of contiguous lost frames is one event. 144010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten virtual size_t underruns() const { return 0; } 145010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 146010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Estimate of number of frames that could be written successfully now without blocking. 147010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // When a write() is actually attempted, the implementation is permitted to return a smaller or 148010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // larger transfer count, however it will make a good faith effort to give an accurate estimate. 149010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Errors: 150010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // NEGOTIATE (Re-)negotiation is needed. 151010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // UNDERRUN write() has not been called frequently enough, or with enough frames to keep up. 152010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // An underrun event is counted, and the caller should re-try this operation. 153010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // WOULD_BLOCK Determining how many frames can be written without blocking would itself block. 154010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten virtual ssize_t availableToWrite() const { return SSIZE_MAX; } 155010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 156010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Transfer data to sink from single input buffer. Implies a copy. 157010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Inputs: 158010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // buffer Non-NULL buffer owned by provider. 159010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // count Maximum number of frames to transfer. 160010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Return value: 161010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // > 0 Number of frames successfully transferred prior to first error. 162010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // = 0 Count was zero. 163010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // < 0 status_t error occurred prior to the first frame transfer. 164010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Errors: 165010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // NEGOTIATE (Re-)negotiation is needed. 166010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // WOULD_BLOCK No frames can be transferred without blocking. 167010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // UNDERRUN write() has not been called frequently enough, or with enough frames to keep up. 168010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // An underrun event is counted, and the caller should re-try this operation. 169010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten virtual ssize_t write(const void *buffer, size_t count) = 0; 170010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 171010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Transfer data to sink using a series of callbacks. More suitable for zero-fill, synthesis, 172010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // and non-contiguous transfers (e.g. circular buffer or writev). 173010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Inputs: 174010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // via Callback function that the sink will call as many times as needed to consume data. 175010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // total Estimate of the number of frames the provider has available. This is an estimate, 176010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // and it can provide a different number of frames during the series of callbacks. 177010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // user Arbitrary void * reserved for data provider. 178010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // block Number of frames per block, that is a suggested value for 'count' in each callback. 179010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Zero means no preference. This parameter is a hint only, and may be ignored. 180010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Return value: 181010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // > 0 Total number of frames successfully transferred prior to first error. 182010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // = 0 Count was zero. 183010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // < 0 status_t error occurred prior to the first frame transfer. 184010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Errors: 185010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // NEGOTIATE (Re-)negotiation is needed. 186010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // WOULD_BLOCK No frames can be transferred without blocking. 187010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // UNDERRUN write() has not been called frequently enough, or with enough frames to keep up. 188010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // An underrun event is counted, and the caller should re-try this operation. 189010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // 190010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // The 'via' callback is called by the data sink as follows: 191010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Inputs: 192010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // user Arbitrary void * reserved for data provider. 193010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // buffer Non-NULL buffer owned by sink that callback should fill in with data, 194010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // up to a maximum of 'count' frames. 195010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // count Maximum number of frames to transfer during this callback. 196010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Return value: 197010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // > 0 Number of frames successfully transferred during this callback prior to first error. 198010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // = 0 Count was zero. 199010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // < 0 status_t error occurred prior to the first frame transfer during this callback. 200010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten virtual ssize_t writeVia(writeVia_t via, size_t total, void *user, size_t block = 0); 201010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 2022c3b2da3049627264b7c6b449a1622f002210f03John Grossman // Get the time (on the LocalTime timeline) at which the first frame of audio of the next write 2032c3b2da3049627264b7c6b449a1622f002210f03John Grossman // operation to this sink will be eventually rendered by the HAL. 2042c3b2da3049627264b7c6b449a1622f002210f03John Grossman // Inputs: 2052c3b2da3049627264b7c6b449a1622f002210f03John Grossman // ts A pointer pointing to the int64_t which will hold the result. 2062c3b2da3049627264b7c6b449a1622f002210f03John Grossman // Return value: 2072c3b2da3049627264b7c6b449a1622f002210f03John Grossman // OK Everything went well, *ts holds the time at which the first audio frame of the next 2082c3b2da3049627264b7c6b449a1622f002210f03John Grossman // write operation will be rendered, or AudioBufferProvider::kInvalidPTS if this sink 2092c3b2da3049627264b7c6b449a1622f002210f03John Grossman // does not know the answer for some reason. Sinks which eventually lead to a HAL 2102c3b2da3049627264b7c6b449a1622f002210f03John Grossman // which implements get_next_write_timestamp may return Invalid temporarily if the DMA 2112c3b2da3049627264b7c6b449a1622f002210f03John Grossman // output of the audio driver has not started yet. Sinks which lead to a HAL which 2122c3b2da3049627264b7c6b449a1622f002210f03John Grossman // does not implement get_next_write_timestamp, or which don't lead to a HAL at all, 2132c3b2da3049627264b7c6b449a1622f002210f03John Grossman // will always return kInvalidPTS. 2142c3b2da3049627264b7c6b449a1622f002210f03John Grossman // <other> Something unexpected happened internally. Check the logs and start debugging. 2152c3b2da3049627264b7c6b449a1622f002210f03John Grossman virtual status_t getNextWriteTimestamp(int64_t *ts) { return INVALID_OPERATION; } 216767094dd98b01baf21de2ad09c27b3c98776cf73Glenn Kasten 217767094dd98b01baf21de2ad09c27b3c98776cf73Glenn Kasten // Returns NO_ERROR if a timestamp is available. The timestamp includes the total number 218767094dd98b01baf21de2ad09c27b3c98776cf73Glenn Kasten // of frames presented to an external observer, together with the value of CLOCK_MONOTONIC 219767094dd98b01baf21de2ad09c27b3c98776cf73Glenn Kasten // as of this presentation count. 220767094dd98b01baf21de2ad09c27b3c98776cf73Glenn Kasten virtual status_t getTimestamp(AudioTimestamp& timestamp) { return INVALID_OPERATION; } 2212c3b2da3049627264b7c6b449a1622f002210f03John Grossman 222010662326b9c43c703725f933e95e0897f8a6bddGlenn Kastenprotected: 223010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten NBAIO_Sink(NBAIO_Format format = Format_Invalid) : NBAIO_Port(format), mFramesWritten(0) { } 224010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten virtual ~NBAIO_Sink() { } 225010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 226010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Implementations are free to ignore these if they don't need them 227010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten size_t mFramesWritten; 228010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten}; 229010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 230010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten// Abstract class (interface) representing a non-blocking data source, for use by a data consumer. 231010662326b9c43c703725f933e95e0897f8a6bddGlenn Kastenclass NBAIO_Source : public NBAIO_Port { 232010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 233010662326b9c43c703725f933e95e0897f8a6bddGlenn Kastenpublic: 234010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 235010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // For the next two APIs: 236010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // 32 bits rolls over after 27 hours at 44.1 kHz; if that concerns you then poll periodically. 237010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 238010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Number of frames read successfully since construction. 239010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten virtual size_t framesRead() const { return mFramesRead; } 240010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 241010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Number of frames lost due to overrun since construction. 242010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Not const because implementations may need to do I/O. 243010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten virtual size_t framesOverrun() /*const*/ { return 0; } 244010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 245010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Number of overruns since construction, where a set of contiguous lost frames is one event. 246010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Not const because implementations may need to do I/O. 247010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten virtual size_t overruns() /*const*/ { return 0; } 248010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 249010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Estimate of number of frames that could be read successfully now. 250010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // When a read() is actually attempted, the implementation is permitted to return a smaller or 251010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // larger transfer count, however it will make a good faith effort to give an accurate estimate. 252010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Errors: 253010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // NEGOTIATE (Re-)negotiation is needed. 254010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // OVERRUN One or more frames were lost due to overrun, try again to read more recent data. 255010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // WOULD_BLOCK Determining how many frames can be read without blocking would itself block. 256010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten virtual ssize_t availableToRead() { return SSIZE_MAX; } 257010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 258010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Transfer data from source into single destination buffer. Implies a copy. 259010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Inputs: 260010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // buffer Non-NULL destination buffer owned by consumer. 261010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // count Maximum number of frames to transfer. 2622c3b2da3049627264b7c6b449a1622f002210f03John Grossman // readPTS The presentation time (on the LocalTime timeline) for which data 2632c3b2da3049627264b7c6b449a1622f002210f03John Grossman // is being requested, or kInvalidPTS if not known. 264010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Return value: 265010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // > 0 Number of frames successfully transferred prior to first error. 266010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // = 0 Count was zero. 267010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // < 0 status_t error occurred prior to the first frame transfer. 268010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Errors: 269010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // NEGOTIATE (Re-)negotiation is needed. 270010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // WOULD_BLOCK No frames can be transferred without blocking. 271010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // OVERRUN read() has not been called frequently enough, or with enough frames to keep up. 272010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // One or more frames were lost due to overrun, try again to read more recent data. 2732c3b2da3049627264b7c6b449a1622f002210f03John Grossman virtual ssize_t read(void *buffer, size_t count, int64_t readPTS) = 0; 274010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 275010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Transfer data from source using a series of callbacks. More suitable for zero-fill, 276010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // synthesis, and non-contiguous transfers (e.g. circular buffer or readv). 277010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Inputs: 278010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // via Callback function that the source will call as many times as needed to provide data. 279010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // total Estimate of the number of frames the consumer desires. This is an estimate, 280010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // and it can consume a different number of frames during the series of callbacks. 281010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // user Arbitrary void * reserved for data consumer. 2822c3b2da3049627264b7c6b449a1622f002210f03John Grossman // readPTS The presentation time (on the LocalTime timeline) for which data 2832c3b2da3049627264b7c6b449a1622f002210f03John Grossman // is being requested, or kInvalidPTS if not known. 284010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // block Number of frames per block, that is a suggested value for 'count' in each callback. 285010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Zero means no preference. This parameter is a hint only, and may be ignored. 286010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Return value: 287010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // > 0 Total number of frames successfully transferred prior to first error. 288010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // = 0 Count was zero. 289010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // < 0 status_t error occurred prior to the first frame transfer. 290010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Errors: 291010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // NEGOTIATE (Re-)negotiation is needed. 292010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // WOULD_BLOCK No frames can be transferred without blocking. 293010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // OVERRUN read() has not been called frequently enough, or with enough frames to keep up. 294010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // One or more frames were lost due to overrun, try again to read more recent data. 295010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // 296010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // The 'via' callback is called by the data source as follows: 297010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Inputs: 298010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // user Arbitrary void * reserved for data consumer. 299010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // dest Non-NULL buffer owned by source that callback should consume data from, 300010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // up to a maximum of 'count' frames. 301010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // count Maximum number of frames to transfer during this callback. 302010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Return value: 303010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // > 0 Number of frames successfully transferred during this callback prior to first error. 304010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // = 0 Count was zero. 305010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // < 0 status_t error occurred prior to the first frame transfer during this callback. 3062c3b2da3049627264b7c6b449a1622f002210f03John Grossman virtual ssize_t readVia(readVia_t via, size_t total, void *user, 3072c3b2da3049627264b7c6b449a1622f002210f03John Grossman int64_t readPTS, size_t block = 0); 308010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 309894d6be4f9b4721c77a01919ecf03b27cec90cc9Glenn Kasten // Invoked asynchronously by corresponding sink when a new timestamp is available. 310894d6be4f9b4721c77a01919ecf03b27cec90cc9Glenn Kasten // Default implementation ignores the timestamp. 311894d6be4f9b4721c77a01919ecf03b27cec90cc9Glenn Kasten virtual void onTimestamp(const AudioTimestamp& timestamp) { } 312894d6be4f9b4721c77a01919ecf03b27cec90cc9Glenn Kasten 313010662326b9c43c703725f933e95e0897f8a6bddGlenn Kastenprotected: 314010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten NBAIO_Source(NBAIO_Format format = Format_Invalid) : NBAIO_Port(format), mFramesRead(0) { } 315010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten virtual ~NBAIO_Source() { } 316010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 317010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // Implementations are free to ignore these if they don't need them 318010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten size_t mFramesRead; 319010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten}; 320010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 321010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten} // namespace android 322010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 323010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten#endif // ANDROID_AUDIO_NBAIO_H 324