AudioFormat
public
final
class
AudioFormat
extends Object
implements
Parcelable
java.lang.Object | |
↳ | android.media.AudioFormat |
The AudioFormat
class is used to access a number of audio format and
channel configuration constants. They are for instance used
in AudioTrack
and AudioRecord
, as valid values in individual parameters of
constructors like AudioTrack#AudioTrack(int, int, int, int, int, int)
, where the fourth
parameter is one of the AudioFormat.ENCODING_*
constants.
The AudioFormat
constants are also used in MediaFormat
to specify
audio related values commonly used in media, such as for MediaFormat#KEY_CHANNEL_MASK
.
The AudioFormat.Builder
class can be used to create instances of
the AudioFormat
format class.
Refer to
AudioFormat.Builder
for documentation on the mechanics of the configuration and building
of such instances. Here we describe the main concepts that the AudioFormat
class
allow you to convey in each instance, they are:
Closely associated with the AudioFormat
is the notion of an
audio frame, which is used throughout the documentation
to represent the minimum size complete unit of audio data.
Sample rate
Expressed in Hz, the sample rate in an AudioFormat
instance expresses the number
of audio samples for each channel per second in the content you are playing or recording. It is
not the sample rate
at which content is rendered or produced. For instance a sound at a media sample rate of 8000Hz
can be played on a device operating at a sample rate of 48000Hz; the sample rate conversion is
automatically handled by the platform, it will not play at 6x speed.
As of API Build.VERSION_CODES.M
,
sample rates up to 192kHz are supported
for AudioRecord
and AudioTrack
, with sample rate conversion
performed as needed.
To improve efficiency and avoid lossy conversions, it is recommended to match the sample rate
for AudioRecord
and AudioTrack
to the endpoint device
sample rate, and limit the sample rate to no more than 48kHz unless there are special
device capabilities that warrant a higher rate.
Encoding
Audio encoding is used to describe the bit representation of audio data, which can be either linear PCM or compressed audio, such as AC3 or DTS.
For linear PCM, the audio encoding describes the sample size, 8 bits, 16 bits, or 32 bits, and the sample representation, integer or float.
-
ENCODING_PCM_8BIT
: The audio sample is a 8 bit unsigned integer in the range [0, 255], with a 128 offset for zero. This is typically stored as a Java byte in a byte array or ByteBuffer. Since the Java byte is signed, be careful with math operations and conversions as the most significant bit is inverted. -
ENCODING_PCM_16BIT
: The audio sample is a 16 bit signed integer typically stored as a Java short in a short array, but when the short is stored in a ByteBuffer, it is native endian (as compared to the default Java big endian). The short has full range from [-32768, 32767], and is sometimes interpreted as fixed point Q.15 data. -
ENCODING_PCM_FLOAT
: Introduced in APIBuild.VERSION_CODES.LOLLIPOP
, this encoding specifies that the audio sample is a 32 bit IEEE single precision float. The sample can be manipulated as a Java float in a float array, though within a ByteBuffer it is stored in native endian byte order. The nominal range ofENCODING_PCM_FLOAT
audio data is [-1.0, 1.0]. It is implementation dependent whether the positive maximum of 1.0 is included in the interval. Values outside of the nominal range are clamped before sending to the endpoint device. Beware that the handling of NaN is undefined; subnormals may be treated as zero; and infinities are generally clamped just like other values forAudioTrack
– try to avoid infinities because they can easily generate a NaN.
To achieve higher audio bit depth than a signed 16 bit integer short, it is recommended to useENCODING_PCM_FLOAT
for audio capture, processing, and playback. Floats are efficiently manipulated by modern CPUs, have greater precision than 24 bit signed integers, and have greater dynamic range than 32 bit signed integers.AudioRecord
as of APIBuild.VERSION_CODES.M
andAudioTrack
as of APIBuild.VERSION_CODES.LOLLIPOP
supportENCODING_PCM_FLOAT
. -
ENCODING_PCM_24BIT_PACKED
: Introduced in APIBuild.VERSION_CODES.S
, this encoding specifies the audio sample is an extended precision 24 bit signed integer stored as a 3 Java bytes in aByteBuffer
or byte array in native endian (seeByteOrder.nativeOrder()
). Each sample has full range from [-8388608, 8388607], and can be interpreted as fixed point Q.23 data. -
ENCODING_PCM_32BIT
: Introduced in APIBuild.VERSION_CODES.S
, this encoding specifies the audio sample is an extended precision 32 bit signed integer stored as a 4 Java bytes in aByteBuffer
or byte array in native endian (seeByteOrder.nativeOrder()
). Each sample has full range from [-2147483648, 2147483647], and can be interpreted as fixed point Q.31 data.
For compressed audio, the encoding specifies the method of compression,
for example ENCODING_AC3
and ENCODING_DTS
. The compressed
audio data is typically stored as bytes in
a byte array or ByteBuffer. When a compressed audio encoding is specified
for an AudioTrack
, it creates a direct (non-mixed) track
for output to an endpoint (such as HDMI) capable of decoding the compressed audio.
For (most) other endpoints, which are not capable of decoding such compressed audio,
you will need to decode the data first, typically by creating a MediaCodec
.
Alternatively, one may use MediaPlayer
for playback of compressed
audio files or streams.
When compressed audio is sent out through a direct AudioTrack
,
it need not be written in exact multiples of the audio access unit;
this differs from MediaCodec
input buffers.
Channel mask
Channel masks are used in AudioTrack
and AudioRecord
to describe
the samples and their arrangement in the audio frame. They are also used in the endpoint (e.g.
a USB audio interface, a DAC connected to headphones) to specify allowable configurations of a
particular device.
As of API Build.VERSION_CODES.M
, there are two types of channel masks:
channel position masks and channel index masks.
Channel position masks
Channel position masks are the original Android channel masks, and are used since APIBuild.VERSION_CODES.BASE
.
For input and output, they imply a positional nature - the location of a speaker or a microphone
for recording or playback.
For a channel position mask, each allowed channel position corresponds to a bit in the channel mask. If that channel position is present in the audio frame, that bit is set, otherwise it is zero. The order of the bits (from lsb to msb) corresponds to the order of that position's sample in the audio frame.
The canonical channel position masks by channel count are as follows:
channel count | channel position mask |
1 | CHANNEL_OUT_MONO |
2 | CHANNEL_OUT_STEREO |
3 | CHANNEL_OUT_STEREO | CHANNEL_OUT_FRONT_CENTER |
4 | CHANNEL_OUT_QUAD |
5 | CHANNEL_OUT_QUAD | CHANNEL_OUT_FRONT_CENTER |
6 | CHANNEL_OUT_5POINT1 |
7 | CHANNEL_OUT_5POINT1 | CHANNEL_OUT_BACK_CENTER |
8 | CHANNEL_OUT_7POINT1_SURROUND |
These masks are an ORed composite of individual channel masks. For example
CHANNEL_OUT_STEREO
is composed of CHANNEL_OUT_FRONT_LEFT
and
CHANNEL_OUT_FRONT_RIGHT
.
The following diagram represents the layout of the output channels, as seen from above the listener (in the center at the "lis" position, facing the front-center channel).
TFL ----- TFC ----- TFR T is Top | \ | / | | FL --- FC --- FR | F is Front | |\ | /| | | | BFL-BFC-BFR | | BF is Bottom Front | | | | | FWL lis FWR | W is Wide | | | | TSL SL TC SR TSR S is Side | | | | | BL --- BC -- BR | B is Back | / \ | TBL ----- TBC ----- TBR C is Center, L/R is Left/Right
Channel index masks
Channel index masks are introduced in APIBuild.VERSION_CODES.M
. They allow
the selection of a particular channel from the source or sink endpoint by number, i.e. the first
channel, the second channel, and so forth. This avoids problems with artificially assigning
positions to channels of an endpoint, or figuring what the ith position bit is within
an endpoint's channel position mask etc.
Here's an example where channel index masks address this confusion: dealing with a 4 channel USB device. Using a position mask, and based on the channel count, this would be a
CHANNEL_OUT_QUAD
device, but really one is only interested in channel 0
through channel 3. The USB device would then have the following individual bit channel masks:
CHANNEL_OUT_FRONT_LEFT
,
CHANNEL_OUT_FRONT_RIGHT
, CHANNEL_OUT_BACK_LEFT
and CHANNEL_OUT_BACK_RIGHT
. But which is channel 0 and which is
channel 3?
For a channel index mask, each channel number is represented as a bit in the mask, from the lsb (channel 0) upwards to the msb, numerically this bit value is
1 << channelNumber
.
A set bit indicates that channel is present in the audio frame, otherwise it is cleared.
The order of the bits also correspond to that channel number's sample order in the audio frame.
For the previous 4 channel USB device example, the device would have a channel index mask
0xF
. Suppose we wanted to select only the first and the third channels; this would
correspond to a channel index mask 0x5
(the first and third bits set). If an
AudioTrack
uses this channel index mask, the audio frame would consist of two
samples, the first sample of each frame routed to channel 0, and the second sample of each frame
routed to channel 2.
The canonical channel index masks by channel count are given by the formula
(1 << channelCount) - 1
.
Use cases
- Channel position mask for an endpoint:
CHANNEL_OUT_FRONT_LEFT
,CHANNEL_OUT_FRONT_CENTER
, etc. for HDMI home theater purposes. - Channel position mask for an audio stream: Creating an
AudioTrack
to output movie content, where 5.1 multichannel output is to be written. - Channel index mask for an endpoint: USB devices for which input and output do not correspond to left or right speaker or microphone.
- Channel index mask for an audio stream: An
AudioRecord
may only want the third and fourth audio channels of the endpoint (i.e. the second channel pair), and not care the about position it corresponds to, in which case the channel index mask is0xC
. MultichannelAudioRecord
sessions should use channel index masks.
Audio Frame
For linear PCM, an audio frame consists of a set of samples captured at the same time,
whose count and
channel association are given by the channel mask,
and whose sample contents are specified by the encoding.
For example, a stereo 16 bit PCM frame consists of
two 16 bit linear PCM samples, with a frame size of 4 bytes.
For compressed audio, an audio frame may alternately
refer to an access unit of compressed data bytes that is logically grouped together for
decoding and bitstream access (e.g. MediaCodec
),
or a single byte of compressed data (e.g. AudioTrack.getBufferSizeInFrames()
),
or the linear PCM frame result from decoding the compressed data
(e.g.AudioTrack.getPlaybackHeadPosition()
),
depending on the context where audio frame is used.
For the purposes of AudioFormat#getFrameSizeInBytes()
, a compressed data format
returns a frame size of 1 byte.
Summary
Nested classes | |
---|---|
class |
AudioFormat.Builder
Builder class for |
Constants | |
---|---|
int |
CHANNEL_CONFIGURATION_DEFAULT
This constant was deprecated
in API level 15.
Use |
int |
CHANNEL_CONFIGURATION_INVALID
This constant was deprecated
in API level 15.
Use |
int |
CHANNEL_CONFIGURATION_MONO
This constant was deprecated
in API level 15.
Use |
int |
CHANNEL_CONFIGURATION_STEREO
This constant was deprecated
in API level 15.
Use |
int |
CHANNEL_INVALID
Invalid audio channel mask |
int |
CHANNEL_IN_BACK
|
int |
CHANNEL_IN_BACK_PROCESSED
|
int |
CHANNEL_IN_DEFAULT
|
int |
CHANNEL_IN_FRONT
|
int |
CHANNEL_IN_FRONT_PROCESSED
|
int |
CHANNEL_IN_LEFT
|
int |
CHANNEL_IN_LEFT_PROCESSED
|
int |
CHANNEL_IN_MONO
|
int |
CHANNEL_IN_PRESSURE
|
int |
CHANNEL_IN_RIGHT
|
int |
CHANNEL_IN_RIGHT_PROCESSED
|
int |
CHANNEL_IN_STEREO
|
int |
CHANNEL_IN_VOICE_DNLINK
|
int |
CHANNEL_IN_VOICE_UPLINK
|
int |
CHANNEL_IN_X_AXIS
|
int |
CHANNEL_IN_Y_AXIS
|
int |
CHANNEL_IN_Z_AXIS
|
int |
CHANNEL_OUT_5POINT1
Output channel mask for 5.1 |
int |
CHANNEL_OUT_5POINT1POINT2
Output channel mask for 5.1.2 Same as 5.1 with the addition of left and right top channels |
int |
CHANNEL_OUT_5POINT1POINT4
Output channel mask for 5.1.4 Same as 5.1 with the addition of four top channels |
int |
CHANNEL_OUT_6POINT1
Output channel mask for 6.1 Same as 5.1 with the addition of the back center channel |
int |
CHANNEL_OUT_7POINT1
This constant was deprecated
in API level 23.
Not the typical 7.1 surround configuration. Use |
int |
CHANNEL_OUT_7POINT1POINT2
Output channel mask for 7.1.2 Same as 7.1 with the addition of left and right top channels |
int |
CHANNEL_OUT_7POINT1POINT4
Output channel mask for 7.1.4 Same as 7.1 with the addition of four top channels |
int |
CHANNEL_OUT_7POINT1_SURROUND
Output channel mask for 7.1 |
int |
CHANNEL_OUT_9POINT1POINT4
Output channel mask for 9.1.4 Same as 7.1.4 with the addition of left and right front wide channels |
int |
CHANNEL_OUT_9POINT1POINT6
Output channel mask for 9.1.6 Same as 9.1.4 with the addition of left and right top side channels |
int |
CHANNEL_OUT_BACK_CENTER
Back center output channel (see BC in channel diagram) |
int |
CHANNEL_OUT_BACK_LEFT
Back left output channel (see BL in channel diagram) |
int |
CHANNEL_OUT_BACK_RIGHT
Back right output channel (see BR in channel diagram) |
int |
CHANNEL_OUT_BOTTOM_FRONT_CENTER
Bottom front center output channel (see BFC in channel diagram below FC) |
int |
CHANNEL_OUT_BOTTOM_FRONT_LEFT
Bottom front left output channel (see BFL in channel diagram below FL) |
int |
CHANNEL_OUT_BOTTOM_FRONT_RIGHT
Bottom front right output channel (see BFR in channel diagram below FR) |
int |
CHANNEL_OUT_DEFAULT
Default audio channel mask |
int |
CHANNEL_OUT_FRONT_CENTER
Front center output channel (see FC in channel diagram) |
int |
CHANNEL_OUT_FRONT_LEFT
Front left output channel (see FL in channel diagram) |
int |
CHANNEL_OUT_FRONT_LEFT_OF_CENTER
|
int |
CHANNEL_OUT_FRONT_RIGHT
Front right output channel (see FR in channel diagram) |
int |
CHANNEL_OUT_FRONT_RIGHT_OF_CENTER
|
int |
CHANNEL_OUT_FRONT_WIDE_LEFT
Front wide left output channel (see FWL in channel diagram) |
int |
CHANNEL_OUT_FRONT_WIDE_RIGHT
Front wide right output channel (see FWR in channel diagram) |
int |
CHANNEL_OUT_LOW_FREQUENCY
LFE "low frequency effect" channel
When used in conjunction with |
int |
CHANNEL_OUT_LOW_FREQUENCY_2
The second LFE channel
When used in conjunction with |
int |
CHANNEL_OUT_MONO
|
int |
CHANNEL_OUT_QUAD
|
int |
CHANNEL_OUT_SIDE_LEFT
Side left output channel (see SL in channel diagram) |
int |
CHANNEL_OUT_SIDE_RIGHT
Side right output channel (see SR in channel diagram) |
int |
CHANNEL_OUT_STEREO
|
int |
CHANNEL_OUT_SURROUND
|
int |
CHANNEL_OUT_TOP_BACK_CENTER
Top back center output channel (see TBC in channel diagram above BC) |
int |
CHANNEL_OUT_TOP_BACK_LEFT
Top back left output channel (see TBL in channel diagram above BL) |
int |
CHANNEL_OUT_TOP_BACK_RIGHT
Top back right output channel (see TBR in channel diagram above BR) |
int |
CHANNEL_OUT_TOP_CENTER
Top center (above listener) output channel (see TC in channel diagram) |
int |
CHANNEL_OUT_TOP_FRONT_CENTER
Top front center output channel (see TFC in channel diagram above FC) |
int |
CHANNEL_OUT_TOP_FRONT_LEFT
Top front left output channel (see TFL in channel diagram above FL) |
int |
CHANNEL_OUT_TOP_FRONT_RIGHT
Top front right output channel (see TFR in channel diagram above FR) |
int |
CHANNEL_OUT_TOP_SIDE_LEFT
Top side left output channel (see TSL in channel diagram above SL) |
int |
CHANNEL_OUT_TOP_SIDE_RIGHT
Top side right output channel (see TSR in channel diagram above SR) |
int |
ENCODING_AAC_ELD
Audio data format: AAC ELD compressed |
int |
ENCODING_AAC_HE_V1
Audio data format: AAC HE V1 compressed |
int |
ENCODING_AAC_HE_V2
Audio data format: AAC HE V2 compressed |
int |
ENCODING_AAC_LC
Audio data format: AAC LC compressed |
int |
ENCODING_AAC_XHE
Audio data format: AAC xHE compressed |
int |
ENCODING_AC3
Audio data format: AC-3 compressed, also known as Dolby Digital |
int |
ENCODING_AC4
Audio data format: AC-4 sync frame transport format |
int |
ENCODING_DEFAULT
Default audio data format |
int |
ENCODING_DOLBY_MAT
Audio data format: Dolby MAT (Metadata-enhanced Audio Transmission) Dolby MAT bitstreams are used to transmit Dolby TrueHD, channel-based PCM, or PCM with metadata (object audio) over HDMI (e.g. Dolby Atmos content). |
int |
ENCODING_DOLBY_TRUEHD
Audio data format: DOLBY TRUEHD compressed |
int |
ENCODING_DRA
Audio data format: DRA compressed |
int |
ENCODING_DSD
Audio data format: Direct Stream Digital |
int |
ENCODING_DTS
Audio data format: DTS compressed |
int |
ENCODING_DTS_HD
Audio data format: DTS HD compressed |
int |
ENCODING_DTS_HD_MA
Audio data format: DTS HD Master Audio compressed DTS HD Master Audio stream is variable bit rate and contains lossless audio. |
int |
ENCODING_DTS_UHD
This constant was deprecated
in API level 34.
Use |
int |
ENCODING_DTS_UHD_P1
Audio data format: DTS UHD Profile-1 compressed (aka DTS:X Profile 1)
Has the same meaning and value as the deprecated |
int |
ENCODING_DTS_UHD_P2
Audio data format: DTS UHD Profile-2 compressed DTS-UHD Profile-2 supports delivery of Channel-Based Audio, Object-Based Audio and High Order Ambisonic presentations up to the fourth order. |
int |
ENCODING_E_AC3
Audio data format: E-AC-3 compressed, also known as Dolby Digital Plus or DD+ |
int |
ENCODING_E_AC3_JOC
Audio data format: E-AC-3-JOC compressed
E-AC-3-JOC streams can be decoded by downstream devices supporting |
int |
ENCODING_IEC61937
Audio data format: compressed audio wrapped in PCM for HDMI or S/PDIF passthrough. |
int |
ENCODING_INVALID
Invalid audio data format |
int |
ENCODING_MP3
Audio data format: MP3 compressed |
int |
ENCODING_MPEGH_BL_L3
Audio data format: MPEG-H baseline profile, level 3 |
int |
ENCODING_MPEGH_BL_L4
Audio data format: MPEG-H baseline profile, level 4 |
int |
ENCODING_MPEGH_LC_L3
Audio data format: MPEG-H low complexity profile, level 3 |
int |
ENCODING_MPEGH_LC_L4
Audio data format: MPEG-H low complexity profile, level 4 |
int |
ENCODING_OPUS
Audio data format: OPUS compressed. |
int |
ENCODING_PCM_16BIT
Audio data format: PCM 16 bit per sample. |
int |
ENCODING_PCM_24BIT_PACKED
Audio data format: PCM 24 bit per sample packed as 3 bytes. |
int |
ENCODING_PCM_32BIT
Audio data format: PCM 32 bit per sample. |
int |
ENCODING_PCM_8BIT
Audio data format: PCM 8 bit per sample. |
int |
ENCODING_PCM_FLOAT
Audio data format: single-precision floating-point per sample |
int |
SAMPLE_RATE_UNSPECIFIED
Sample rate will be a route-dependent value. |
Inherited constants |
---|
Fields | |
---|---|
public
static
final
Creator<AudioFormat> |
CREATOR
|
Public methods | |
---|---|
int
|
describeContents()
Describe the kinds of special objects contained in this Parcelable instance's marshaled representation. |
boolean
|
equals(Object o)
Indicates whether some other object is "equal to" this one. |
int
|
getChannelCount()
Return the channel count. |
int
|
getChannelIndexMask()
Return the channel index mask. |
int
|
getChannelMask()
Return the channel mask. |
int
|
getEncoding()
Return the encoding. |
int
|
getFrameSizeInBytes()
Return the frame size in bytes. |
int
|
getSampleRate()
Return the sample rate. |
int
|
hashCode()
Returns a hash code value for the object. |
String
|
toString()
Returns a string representation of the object. |
void
|
writeToParcel(Parcel dest, int flags)
Flatten this object in to a Parcel. |
Inherited methods | |
---|---|
Constants
CHANNEL_CONFIGURATION_DEFAULT
public static final int CHANNEL_CONFIGURATION_DEFAULT
This constant was deprecated
in API level 15.
Use CHANNEL_OUT_DEFAULT
or CHANNEL_IN_DEFAULT
instead.
Constant Value: 1 (0x00000001)
CHANNEL_CONFIGURATION_INVALID
public static final int CHANNEL_CONFIGURATION_INVALID
This constant was deprecated
in API level 15.
Use CHANNEL_INVALID
instead.
Constant Value: 0 (0x00000000)
CHANNEL_CONFIGURATION_MONO
public static final int CHANNEL_CONFIGURATION_MONO
This constant was deprecated
in API level 15.
Use CHANNEL_OUT_MONO
or CHANNEL_IN_MONO
instead.
Constant Value: 2 (0x00000002)
CHANNEL_CONFIGURATION_STEREO
public static final int CHANNEL_CONFIGURATION_STEREO
This constant was deprecated
in API level 15.
Use CHANNEL_OUT_STEREO
or CHANNEL_IN_STEREO
instead.
Constant Value: 3 (0x00000003)
CHANNEL_INVALID
public static final int CHANNEL_INVALID
Invalid audio channel mask
Constant Value: 0 (0x00000000)
CHANNEL_IN_BACK
public static final int CHANNEL_IN_BACK
Constant Value: 32 (0x00000020)
CHANNEL_IN_BACK_PROCESSED
public static final int CHANNEL_IN_BACK_PROCESSED
Constant Value: 512 (0x00000200)
CHANNEL_IN_DEFAULT
public static final int CHANNEL_IN_DEFAULT
Constant Value: 1 (0x00000001)
CHANNEL_IN_FRONT
public static final int CHANNEL_IN_FRONT
Constant Value: 16 (0x00000010)
CHANNEL_IN_FRONT_PROCESSED
public static final int CHANNEL_IN_FRONT_PROCESSED
Constant Value: 256 (0x00000100)
CHANNEL_IN_LEFT
public static final int CHANNEL_IN_LEFT
Constant Value: 4 (0x00000004)
CHANNEL_IN_LEFT_PROCESSED
public static final int CHANNEL_IN_LEFT_PROCESSED
Constant Value: 64 (0x00000040)
CHANNEL_IN_MONO
public static final int CHANNEL_IN_MONO
Constant Value: 16 (0x00000010)
CHANNEL_IN_PRESSURE
public static final int CHANNEL_IN_PRESSURE
Constant Value: 1024 (0x00000400)
CHANNEL_IN_RIGHT
public static final int CHANNEL_IN_RIGHT
Constant Value: 8 (0x00000008)
CHANNEL_IN_RIGHT_PROCESSED
public static final int CHANNEL_IN_RIGHT_PROCESSED
Constant Value: 128 (0x00000080)
CHANNEL_IN_STEREO
public static final int CHANNEL_IN_STEREO
Constant Value: 12 (0x0000000c)
CHANNEL_IN_VOICE_DNLINK
public static final int CHANNEL_IN_VOICE_DNLINK
Constant Value: 32768 (0x00008000)
CHANNEL_IN_VOICE_UPLINK
public static final int CHANNEL_IN_VOICE_UPLINK
Constant Value: 16384 (0x00004000)
CHANNEL_IN_X_AXIS
public static final int CHANNEL_IN_X_AXIS
Constant Value: 2048 (0x00000800)
CHANNEL_IN_Y_AXIS
public static final int CHANNEL_IN_Y_AXIS
Constant Value: 4096 (0x00001000)
CHANNEL_IN_Z_AXIS
public static final int CHANNEL_IN_Z_AXIS
Constant Value: 8192 (0x00002000)
CHANNEL_OUT_5POINT1
public static final int CHANNEL_OUT_5POINT1
Output channel mask for 5.1
Constant Value: 252 (0x000000fc)
CHANNEL_OUT_5POINT1POINT2
public static final int CHANNEL_OUT_5POINT1POINT2
Output channel mask for 5.1.2 Same as 5.1 with the addition of left and right top channels
Constant Value: 3145980 (0x003000fc)
CHANNEL_OUT_5POINT1POINT4
public static final int CHANNEL_OUT_5POINT1POINT4
Output channel mask for 5.1.4 Same as 5.1 with the addition of four top channels
Constant Value: 737532 (0x000b40fc)
CHANNEL_OUT_6POINT1
public static final int CHANNEL_OUT_6POINT1
Output channel mask for 6.1 Same as 5.1 with the addition of the back center channel
Constant Value: 1276 (0x000004fc)
CHANNEL_OUT_7POINT1
public static final int CHANNEL_OUT_7POINT1
This constant was deprecated
in API level 23.
Not the typical 7.1 surround configuration. Use CHANNEL_OUT_7POINT1_SURROUND
instead.
Constant Value: 1020 (0x000003fc)
CHANNEL_OUT_7POINT1POINT2
public static final int CHANNEL_OUT_7POINT1POINT2
Output channel mask for 7.1.2 Same as 7.1 with the addition of left and right top channels
Constant Value: 3152124 (0x003018fc)
CHANNEL_OUT_7POINT1POINT4
public static final int CHANNEL_OUT_7POINT1POINT4
Output channel mask for 7.1.4 Same as 7.1 with the addition of four top channels
Constant Value: 743676 (0x000b58fc)
CHANNEL_OUT_7POINT1_SURROUND
public static final int CHANNEL_OUT_7POINT1_SURROUND
Output channel mask for 7.1
Constant Value: 6396 (0x000018fc)
CHANNEL_OUT_9POINT1POINT4
public static final int CHANNEL_OUT_9POINT1POINT4
Output channel mask for 9.1.4 Same as 7.1.4 with the addition of left and right front wide channels
Constant Value: 202070268 (0x0c0b58fc)
CHANNEL_OUT_9POINT1POINT6
public static final int CHANNEL_OUT_9POINT1POINT6
Output channel mask for 9.1.6 Same as 9.1.4 with the addition of left and right top side channels
Constant Value: 205215996 (0x0c3b58fc)
CHANNEL_OUT_BACK_CENTER
public static final int CHANNEL_OUT_BACK_CENTER
Back center output channel (see BC in channel diagram)
Constant Value: 1024 (0x00000400)
CHANNEL_OUT_BACK_LEFT
public static final int CHANNEL_OUT_BACK_LEFT
Back left output channel (see BL in channel diagram)
Constant Value: 64 (0x00000040)
CHANNEL_OUT_BACK_RIGHT
public static final int CHANNEL_OUT_BACK_RIGHT
Back right output channel (see BR in channel diagram)
Constant Value: 128 (0x00000080)
CHANNEL_OUT_BOTTOM_FRONT_CENTER
public static final int CHANNEL_OUT_BOTTOM_FRONT_CENTER
Bottom front center output channel (see BFC in channel diagram below FC)
Constant Value: 8388608 (0x00800000)
CHANNEL_OUT_BOTTOM_FRONT_LEFT
public static final int CHANNEL_OUT_BOTTOM_FRONT_LEFT
Bottom front left output channel (see BFL in channel diagram below FL)
Constant Value: 4194304 (0x00400000)
CHANNEL_OUT_BOTTOM_FRONT_RIGHT
public static final int CHANNEL_OUT_BOTTOM_FRONT_RIGHT
Bottom front right output channel (see BFR in channel diagram below FR)
Constant Value: 16777216 (0x01000000)
CHANNEL_OUT_DEFAULT
public static final int CHANNEL_OUT_DEFAULT
Default audio channel mask
Constant Value: 1 (0x00000001)
CHANNEL_OUT_FRONT_CENTER
public static final int CHANNEL_OUT_FRONT_CENTER
Front center output channel (see FC in channel diagram)
Constant Value: 16 (0x00000010)
CHANNEL_OUT_FRONT_LEFT
public static final int CHANNEL_OUT_FRONT_LEFT
Front left output channel (see FL in channel diagram)
Constant Value: 4 (0x00000004)
CHANNEL_OUT_FRONT_LEFT_OF_CENTER
public static final int CHANNEL_OUT_FRONT_LEFT_OF_CENTER
Constant Value: 256 (0x00000100)
CHANNEL_OUT_FRONT_RIGHT
public static final int CHANNEL_OUT_FRONT_RIGHT
Front right output channel (see FR in channel diagram)
Constant Value: 8 (0x00000008)
CHANNEL_OUT_FRONT_RIGHT_OF_CENTER
public static final int CHANNEL_OUT_FRONT_RIGHT_OF_CENTER
Constant Value: 512 (0x00000200)
CHANNEL_OUT_FRONT_WIDE_LEFT
public static final int CHANNEL_OUT_FRONT_WIDE_LEFT
Front wide left output channel (see FWL in channel diagram)
Constant Value: 67108864 (0x04000000)
CHANNEL_OUT_FRONT_WIDE_RIGHT
public static final int CHANNEL_OUT_FRONT_WIDE_RIGHT
Front wide right output channel (see FWR in channel diagram)
Constant Value: 134217728 (0x08000000)
CHANNEL_OUT_LOW_FREQUENCY
public static final int CHANNEL_OUT_LOW_FREQUENCY
LFE "low frequency effect" channel
When used in conjunction with CHANNEL_OUT_LOW_FREQUENCY_2
, it is intended
to contain the left low-frequency effect signal, also referred to as "LFE1"
in ITU-R BS.2159-8
Constant Value: 32 (0x00000020)
CHANNEL_OUT_LOW_FREQUENCY_2
public static final int CHANNEL_OUT_LOW_FREQUENCY_2
The second LFE channel
When used in conjunction with CHANNEL_OUT_LOW_FREQUENCY
, it is intended
to contain the right low-frequency effect signal, also referred to as "LFE2"
in ITU-R BS.2159-8
Constant Value: 33554432 (0x02000000)
CHANNEL_OUT_MONO
public static final int CHANNEL_OUT_MONO
Constant Value: 4 (0x00000004)
CHANNEL_OUT_QUAD
public static final int CHANNEL_OUT_QUAD
Constant Value: 204 (0x000000cc)
CHANNEL_OUT_SIDE_LEFT
public static final int CHANNEL_OUT_SIDE_LEFT
Side left output channel (see SL in channel diagram)
Constant Value: 2048 (0x00000800)
CHANNEL_OUT_SIDE_RIGHT
public static final int CHANNEL_OUT_SIDE_RIGHT
Side right output channel (see SR in channel diagram)
Constant Value: 4096 (0x00001000)
CHANNEL_OUT_STEREO
public static final int CHANNEL_OUT_STEREO
Constant Value: 12 (0x0000000c)
CHANNEL_OUT_SURROUND
public static final int CHANNEL_OUT_SURROUND
Constant Value: 1052 (0x0000041c)
CHANNEL_OUT_TOP_BACK_CENTER
public static final int CHANNEL_OUT_TOP_BACK_CENTER
Top back center output channel (see TBC in channel diagram above BC)
Constant Value: 262144 (0x00040000)
CHANNEL_OUT_TOP_BACK_LEFT
public static final int CHANNEL_OUT_TOP_BACK_LEFT
Top back left output channel (see TBL in channel diagram above BL)
Constant Value: 131072 (0x00020000)
CHANNEL_OUT_TOP_BACK_RIGHT
public static final int CHANNEL_OUT_TOP_BACK_RIGHT
Top back right output channel (see TBR in channel diagram above BR)
Constant Value: 524288 (0x00080000)
CHANNEL_OUT_TOP_CENTER
public static final int CHANNEL_OUT_TOP_CENTER
Top center (above listener) output channel (see TC in channel diagram)
Constant Value: 8192 (0x00002000)
CHANNEL_OUT_TOP_FRONT_CENTER
public static final int CHANNEL_OUT_TOP_FRONT_CENTER
Top front center output channel (see TFC in channel diagram above FC)
Constant Value: 32768 (0x00008000)
CHANNEL_OUT_TOP_FRONT_LEFT
public static final int CHANNEL_OUT_TOP_FRONT_LEFT
Top front left output channel (see TFL in channel diagram above FL)
Constant Value: 16384 (0x00004000)
CHANNEL_OUT_TOP_FRONT_RIGHT
public static final int CHANNEL_OUT_TOP_FRONT_RIGHT
Top front right output channel (see TFR in channel diagram above FR)
Constant Value: 65536 (0x00010000)
CHANNEL_OUT_TOP_SIDE_LEFT
public static final int CHANNEL_OUT_TOP_SIDE_LEFT
Top side left output channel (see TSL in channel diagram above SL)
Constant Value: 1048576 (0x00100000)
CHANNEL_OUT_TOP_SIDE_RIGHT
public static final int CHANNEL_OUT_TOP_SIDE_RIGHT
Top side right output channel (see TSR in channel diagram above SR)
Constant Value: 2097152 (0x00200000)
ENCODING_AAC_ELD
public static final int ENCODING_AAC_ELD
Audio data format: AAC ELD compressed
Constant Value: 15 (0x0000000f)
ENCODING_AAC_HE_V1
public static final int ENCODING_AAC_HE_V1
Audio data format: AAC HE V1 compressed
Constant Value: 11 (0x0000000b)
ENCODING_AAC_HE_V2
public static final int ENCODING_AAC_HE_V2
Audio data format: AAC HE V2 compressed
Constant Value: 12 (0x0000000c)
ENCODING_AAC_LC
public static final int ENCODING_AAC_LC
Audio data format: AAC LC compressed
Constant Value: 10 (0x0000000a)
ENCODING_AAC_XHE
public static final int ENCODING_AAC_XHE
Audio data format: AAC xHE compressed
Constant Value: 16 (0x00000010)
ENCODING_AC3
public static final int ENCODING_AC3
Audio data format: AC-3 compressed, also known as Dolby Digital
Constant Value: 5 (0x00000005)
ENCODING_AC4
public static final int ENCODING_AC4
Audio data format: AC-4 sync frame transport format
Constant Value: 17 (0x00000011)
ENCODING_DEFAULT
public static final int ENCODING_DEFAULT
Default audio data format
Constant Value: 1 (0x00000001)
ENCODING_DOLBY_MAT
public static final int ENCODING_DOLBY_MAT
Audio data format: Dolby MAT (Metadata-enhanced Audio Transmission) Dolby MAT bitstreams are used to transmit Dolby TrueHD, channel-based PCM, or PCM with metadata (object audio) over HDMI (e.g. Dolby Atmos content).
Constant Value: 19 (0x00000013)
ENCODING_DOLBY_TRUEHD
public static final int ENCODING_DOLBY_TRUEHD
Audio data format: DOLBY TRUEHD compressed
Constant Value: 14 (0x0000000e)
ENCODING_DRA
public static final int ENCODING_DRA
Audio data format: DRA compressed
Constant Value: 28 (0x0000001c)
ENCODING_DSD
public static final int ENCODING_DSD
Audio data format: Direct Stream Digital
Constant Value: 31 (0x0000001f)
ENCODING_DTS
public static final int ENCODING_DTS
Audio data format: DTS compressed
Constant Value: 7 (0x00000007)
ENCODING_DTS_HD
public static final int ENCODING_DTS_HD
Audio data format: DTS HD compressed
Constant Value: 8 (0x00000008)
ENCODING_DTS_HD_MA
public static final int ENCODING_DTS_HD_MA
Audio data format: DTS HD Master Audio compressed
DTS HD Master Audio stream is variable bit rate and contains lossless audio.
Use ENCODING_DTS_HD_MA
for lossless audio content (DTS-HD MA Lossless)
and use ENCODING_DTS_HD
for other DTS bitstreams with extension substream
(DTS 8Ch Discrete, DTS Hi Res, DTS Express).
Constant Value: 29 (0x0000001d)
ENCODING_DTS_UHD
public static final int ENCODING_DTS_UHD
This constant was deprecated
in API level 34.
Use ENCODING_DTS_UHD_P1
instead.
Audio data format: DTS UHD Profile-1 compressed (aka DTS:X Profile 1) Has the same meaning and value as ENCODING_DTS_UHD_P1.
Constant Value: 27 (0x0000001b)
ENCODING_DTS_UHD_P1
public static final int ENCODING_DTS_UHD_P1
Audio data format: DTS UHD Profile-1 compressed (aka DTS:X Profile 1)
Has the same meaning and value as the deprecated ENCODING_DTS_UHD
.
Constant Value: 27 (0x0000001b)
ENCODING_DTS_UHD_P2
public static final int ENCODING_DTS_UHD_P2
Audio data format: DTS UHD Profile-2 compressed
DTS-UHD Profile-2 supports delivery of Channel-Based Audio, Object-Based Audio
and High Order Ambisonic presentations up to the fourth order.
Use ENCODING_DTS_UHD_P1
to transmit DTS UHD Profile 1 (aka DTS:X Profile 1)
bitstream.
Use ENCODING_DTS_UHD_P2
to transmit DTS UHD Profile 2 (aka DTS:X Profile 2)
bitstream.
Constant Value: 30 (0x0000001e)
ENCODING_E_AC3
public static final int ENCODING_E_AC3
Audio data format: E-AC-3 compressed, also known as Dolby Digital Plus or DD+
Constant Value: 6 (0x00000006)
ENCODING_E_AC3_JOC
public static final int ENCODING_E_AC3_JOC
Audio data format: E-AC-3-JOC compressed
E-AC-3-JOC streams can be decoded by downstream devices supporting ENCODING_E_AC3
.
Use ENCODING_E_AC3
as the AudioTrack encoding when the downstream device
supports ENCODING_E_AC3
but not ENCODING_E_AC3_JOC
.
Constant Value: 18 (0x00000012)
ENCODING_IEC61937
public static final int ENCODING_IEC61937
Audio data format: compressed audio wrapped in PCM for HDMI
or S/PDIF passthrough.
For devices whose SDK version is less than Build.VERSION_CODES.S
, the
channel mask of IEC61937 track must be CHANNEL_OUT_STEREO
.
Data should be written to the stream in a short[] array.
If the data is written in a byte[] array then there may be endian problems
on some platforms when converting to short internally.
Constant Value: 13 (0x0000000d)
ENCODING_INVALID
public static final int ENCODING_INVALID
Invalid audio data format
Constant Value: 0 (0x00000000)
ENCODING_MP3
public static final int ENCODING_MP3
Audio data format: MP3 compressed
Constant Value: 9 (0x00000009)
ENCODING_MPEGH_BL_L3
public static final int ENCODING_MPEGH_BL_L3
Audio data format: MPEG-H baseline profile, level 3
Constant Value: 23 (0x00000017)
ENCODING_MPEGH_BL_L4
public static final int ENCODING_MPEGH_BL_L4
Audio data format: MPEG-H baseline profile, level 4
Constant Value: 24 (0x00000018)
ENCODING_MPEGH_LC_L3
public static final int ENCODING_MPEGH_LC_L3
Audio data format: MPEG-H low complexity profile, level 3
Constant Value: 25 (0x00000019)
ENCODING_MPEGH_LC_L4
public static final int ENCODING_MPEGH_LC_L4
Audio data format: MPEG-H low complexity profile, level 4
Constant Value: 26 (0x0000001a)
ENCODING_OPUS
public static final int ENCODING_OPUS
Audio data format: OPUS compressed.
Constant Value: 20 (0x00000014)
ENCODING_PCM_16BIT
public static final int ENCODING_PCM_16BIT
Audio data format: PCM 16 bit per sample. Guaranteed to be supported by devices.
Constant Value: 2 (0x00000002)
ENCODING_PCM_24BIT_PACKED
public static final int ENCODING_PCM_24BIT_PACKED
Audio data format: PCM 24 bit per sample packed as 3 bytes. The bytes are in little-endian order, so the least significant byte comes first in the byte array. Not guaranteed to be supported by devices, may be emulated if not supported.
Constant Value: 21 (0x00000015)
ENCODING_PCM_32BIT
public static final int ENCODING_PCM_32BIT
Audio data format: PCM 32 bit per sample. Not guaranteed to be supported by devices, may be emulated if not supported.
Constant Value: 22 (0x00000016)
ENCODING_PCM_8BIT
public static final int ENCODING_PCM_8BIT
Audio data format: PCM 8 bit per sample. Not guaranteed to be supported by devices.
Constant Value: 3 (0x00000003)
ENCODING_PCM_FLOAT
public static final int ENCODING_PCM_FLOAT
Audio data format: single-precision floating-point per sample
Constant Value: 4 (0x00000004)
SAMPLE_RATE_UNSPECIFIED
public static final int SAMPLE_RATE_UNSPECIFIED
Sample rate will be a route-dependent value. For AudioTrack, it is usually the sink sample rate, and for AudioRecord it is usually the source sample rate.
Constant Value: 0 (0x00000000)
Fields
Public methods
describeContents
public int describeContents ()
Describe the kinds of special objects contained in this Parcelable
instance's marshaled representation. For example, if the object will
include a file descriptor in the output of writeToParcel(android.os.Parcel, int)
,
the return value of this method must include the
CONTENTS_FILE_DESCRIPTOR
bit.
Returns | |
---|---|
int |
a bitmask indicating the set of special object types marshaled
by this Parcelable object instance.
Value is either 0 or CONTENTS_FILE_DESCRIPTOR |
equals
public boolean equals (Object o)
Indicates whether some other object is "equal to" this one.
The equals
method implements an equivalence relation
on non-null object references:
- It is reflexive: for any non-null reference value
x
,x.equals(x)
should returntrue
. - It is symmetric: for any non-null reference values
x
andy
,x.equals(y)
should returntrue
if and only ify.equals(x)
returnstrue
. - It is transitive: for any non-null reference values
x
,y
, andz
, ifx.equals(y)
returnstrue
andy.equals(z)
returnstrue
, thenx.equals(z)
should returntrue
. - It is consistent: for any non-null reference values
x
andy
, multiple invocations ofx.equals(y)
consistently returntrue
or consistently returnfalse
, provided no information used inequals
comparisons on the objects is modified. - For any non-null reference value
x
,x.equals(null)
should returnfalse
.
An equivalence relation partitions the elements it operates on into equivalence classes; all the members of an equivalence class are equal to each other. Members of an equivalence class are substitutable for each other, at least for some purposes.
Parameters | |
---|---|
o |
Object : the reference object with which to compare. |
Returns | |
---|---|
boolean |
true if this object is the same as the obj
argument; false otherwise. |
getChannelCount
public int getChannelCount ()
Return the channel count.
Returns | |
---|---|
int |
the channel count derived from the channel position mask or the channel index mask. Zero is returned if both the channel position mask and the channel index mask are not set. |
getChannelIndexMask
public int getChannelIndexMask ()
Return the channel index mask.
See the section on channel masks for more information about
the difference between index-based masks, and position-based masks (as returned
by getChannelMask()
).
Returns | |
---|---|
int |
one of the values that can be set in Builder#setChannelIndexMask(int) or
AudioFormat#CHANNEL_INVALID if not set or an invalid mask was used. |
getChannelMask
public int getChannelMask ()
Return the channel mask.
See the section on channel masks for more information about
the difference between index-based masks(as returned by getChannelIndexMask()
) and
the position-based mask returned by this function.
Returns | |
---|---|
int |
one of the values that can be set in Builder#setChannelMask(int) or
AudioFormat#CHANNEL_INVALID if not set. |
getEncoding
public int getEncoding ()
Return the encoding. See the section on encodings for more information about the different types of supported audio encoding.
getFrameSizeInBytes
public int getFrameSizeInBytes ()
Return the frame size in bytes.
For PCM or PCM packed compressed data this is the size of a sample multiplied
by the channel count. For all other cases, including invalid/unset channel masks,
this will return 1 byte.
As an example, a stereo 16-bit PCM format would have a frame size of 4 bytes,
an 8 channel float PCM format would have a frame size of 32 bytes,
and a compressed data format (not packed in PCM) would have a frame size of 1 byte.
Both AudioRecord
or AudioTrack
process data in multiples of
this frame size.
Returns | |
---|---|
int |
The audio frame size in bytes corresponding to the encoding and the channel mask. Value is 1 or greater |
getSampleRate
public int getSampleRate ()
Return the sample rate.
Returns | |
---|---|
int |
one of the values that can be set in Builder#setSampleRate(int) or
SAMPLE_RATE_UNSPECIFIED if not set. |
hashCode
public int hashCode ()
Returns a hash code value for the object. This method is
supported for the benefit of hash tables such as those provided by
HashMap
.
The general contract of hashCode
is:
- Whenever it is invoked on the same object more than once during
an execution of a Java application, the
hashCode
method must consistently return the same integer, provided no information used inequals
comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application. - If two objects are equal according to the
equals
method, then calling thehashCode
method on each of the two objects must produce the same integer result. - It is not required that if two objects are unequal
according to the
equals
method, then calling thehashCode
method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables.
Returns | |
---|---|
int |
a hash code value for this object. |
toString
public String toString ()
Returns a string representation of the object.
Returns | |
---|---|
String |
a string representation of the object. |
writeToParcel
public void writeToParcel (Parcel dest, int flags)
Flatten this object in to a Parcel.
Parameters | |
---|---|
dest |
Parcel : The Parcel in which the object should be written.
This value cannot be null . |
flags |
int : Additional flags about how the object should be written.
May be 0 or Parcelable.PARCELABLE_WRITE_RETURN_VALUE .
Value is either 0 or a combination of Parcelable.PARCELABLE_WRITE_RETURN_VALUE , and android.os.Parcelable.PARCELABLE_ELIDE_DUPLICATES |
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Last updated 2024-04-11 UTC.