2013-01-15 05:09:38 -08:00
|
|
|
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
|
|
|
|
|
/* vim:set ts=2 sw=2 sts=2 et cindent: */
|
|
|
|
|
/* This Source Code Form is subject to the terms of the Mozilla Public
|
|
|
|
|
* License, v. 2.0. If a copy of the MPL was not distributed with this
|
|
|
|
|
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
|
|
|
|
|
#ifndef MOZILLA_AUDIOCHANNELFORMAT_H_
|
|
|
|
|
#define MOZILLA_AUDIOCHANNELFORMAT_H_
|
|
|
|
|
|
2013-09-05 13:25:17 -07:00
|
|
|
#include <stdint.h>
|
|
|
|
|
|
2014-03-15 12:00:17 -07:00
|
|
|
#include "nsTArrayForwardDeclare.h"
|
2013-01-15 05:09:38 -08:00
|
|
|
|
|
|
|
|
namespace mozilla {
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* This file provides utilities for upmixing and downmixing channels.
|
|
|
|
|
*
|
|
|
|
|
* The channel layouts, upmixing and downmixing are consistent with the
|
|
|
|
|
* Web Audio spec.
|
|
|
|
|
*
|
|
|
|
|
* Channel layouts for up to 6 channels:
|
|
|
|
|
* mono { M }
|
|
|
|
|
* stereo { L, R }
|
|
|
|
|
* { L, R, C }
|
|
|
|
|
* quad { L, R, SL, SR }
|
|
|
|
|
* { L, R, C, SL, SR }
|
|
|
|
|
* 5.1 { L, R, C, LFE, SL, SR }
|
|
|
|
|
*
|
|
|
|
|
* Only 1, 2, 4 and 6 are currently defined in Web Audio.
|
|
|
|
|
*/
|
|
|
|
|
|
|
|
|
|
/**
|
|
|
|
|
* Return a channel count whose channel layout includes all the channels from
|
|
|
|
|
* aChannels1 and aChannels2.
|
|
|
|
|
*/
|
|
|
|
|
uint32_t
|
|
|
|
|
GetAudioChannelsSuperset(uint32_t aChannels1, uint32_t aChannels2);
|
|
|
|
|
|
|
|
|
|
/**
|
|
|
|
|
* Given an array of input channel data, and an output channel count,
|
|
|
|
|
* replaces the array with an array of upmixed channels.
|
|
|
|
|
* This shuffles the array and may set some channel buffers to aZeroChannel.
|
|
|
|
|
* Don't call this with input count >= output count.
|
|
|
|
|
* This may return *more* channels than requested. In that case, downmixing
|
|
|
|
|
* is required to to get to aOutputChannelCount. (This is how we handle
|
|
|
|
|
* odd cases like 3 -> 4 upmixing.)
|
|
|
|
|
* If aChannelArray.Length() was the input to one of a series of
|
|
|
|
|
* GetAudioChannelsSuperset calls resulting in aOutputChannelCount,
|
|
|
|
|
* no downmixing will be required.
|
|
|
|
|
*/
|
|
|
|
|
void
|
|
|
|
|
AudioChannelsUpMix(nsTArray<const void*>* aChannelArray,
|
|
|
|
|
uint32_t aOutputChannelCount,
|
|
|
|
|
const void* aZeroChannel);
|
|
|
|
|
|
|
|
|
|
/**
|
|
|
|
|
* Given an array of input channels (which must be float format!),
|
|
|
|
|
* downmix to aOutputChannelCount, and copy the results to the
|
|
|
|
|
* channel buffers in aOutputChannels.
|
|
|
|
|
* Don't call this with input count <= output count.
|
|
|
|
|
*/
|
|
|
|
|
void
|
|
|
|
|
AudioChannelsDownMix(const nsTArray<const void*>& aChannelArray,
|
|
|
|
|
float** aOutputChannels,
|
|
|
|
|
uint32_t aOutputChannelCount,
|
|
|
|
|
uint32_t aDuration);
|
|
|
|
|
|
|
|
|
|
// A version of AudioChannelsDownMix that downmixes int16_ts may be required.
|
|
|
|
|
|
|
|
|
|
} // namespace mozilla
|
|
|
|
|
|
|
|
|
|
#endif /* MOZILLA_AUDIOCHANNELFORMAT_H_ */
|
