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<DolbyDigitalPlusAudioProfile>

Updated: February 10, 2015

The attributes described in this topic allow you to configure Dolby Digital Plus encoding using the Azure Media Encoder.

<Presets>
  <Preset>
    <MediaFile>
      <OutputFormat>
        <MP4OutputFormat>
          <AudioProfile>
            <DolbyDigitalPlusAudioProfile>

<DolbyDigitalPlusAudioProfile    AudioCodingMode="Mode20"    BitsPerSample=”24”    Channels=”2"    Codec="DolbyDigitalPlus"    DCHighpassFilter="True"    DialogNormalization="-31"    DolbySurroundMode="NotIndicated"    EncoderMode="DolbyDigitalPlus"    LFELowpassFilter="False"    LFEOn="False"    LineModeDynamicRangeControl="FilmStandard"    LoRoCenterMixLevel="-3.0"    LoRoSurroundMixLevel="-3.0"    LtRtCenterMixLevel="-3.0"    LtRtSurroundMixLevel="-3.0"    NinetyDegreePhaseShiftSurrounds="False"    RFModeDynamicRangeControl="FilmStandard"    SamplesPerSecond="48000"    StereoDownmixPreference="NotIndicated"    ThreeDBAttenuationSurrounds="False">        <Bitrate>          <ConstantBitrate            Bitrate="128"            IsTwoPass="False"            BufferWindow="00:00:00" />        </Bitrate>      </DolbyDigitalPlusAudioProfile>

The following sections describe attributes, child elements, and parent elements. Click on the attribute name to see the allowable values for that attribute.

Attributes

 

Attribute Description

AudioCodingMode

This attribute determines which channels will be encoded into the E-AC-3 bit stream. When encoding a source with a different number of channels than the Dolby Digital Plus settings specified in your configuration, a channel mixing operation will be performed. The method used to mix the channels affects overall loudness by design. This should be taken into account when setting the dialog normalization settings for your encoding.

BitsPerSample

The number of bits used for each audio sample.

Channels

The number of audio channels encoded.

Codec

This attribute determines the codec used for encoding.

DCHighpassFilter

This attribute determines whether the DC component is blocked by a 3Hz high pass filter, applied to all channels.

DialogNormalization

This attribute determines the average dialogue level relative to digital 100%. Allowed values are in the range {-31, -30, …, -2, -1} dB. Recommended values are shown in the DialogNormalization attribute section below. Care should be taken when setting this attribute to a non-default value. Many things can affect the setting needed including, the loudness of the source, the NormalizeAudio and AudioGainLevel attributes of the <MediaFile> config element, and channel mixing (encoding a stereo source as 5.1 or a 5.1 source as stereo). Only use a non-default value when you understand these settings.

noteNote
If you intend to provide a value other than one the default values listed in the DialogNormalization section below, by running loudness measurement algorithms on the source, do not set the NormalizeAudio or AudioGainLevel attributes of the <MediaFile> element.

DolbySurroundMode

This attribute determines whether the encoded audio is a stereo mix encoded in Dolby Surround. It takes effect only if the AudioCodingMode is set to Mode20.

EncoderMode

This attribute specifies the encoder should generate Dolby Digital Plus encodings.

LFELowpassFilter

This attribute determines whether a 120 Hz low pass filter is applied to the Low Frequency Effects (LFE) channel. This setting must be set to False if LFEOn is set to False.

LFEOn

This attribute determines whether the Low Frequency Effects (LFE) channel is coded. Permitted values are False for AudioCodingMode of Mode10 or Mode20, and True for Mode32.

LineModeDynamicRangeControl

This attribute determines the selected dynamic range compression characteristics in Line mode from a set of presets. Line mode is a dynamic range control that reduces the dynamic range of audio content. When compared with RF mode, music and loud noises sound louder but voices will sound quieter. Care should be taken when setting this attribute. Many things can affect the setting needed including, the loudness of the source, the NormalizeAudio and AudioGainLevel attributes of the <MediaFile> config element, and channel mixing (encoding a stereo source as 5.1 or a 5.1 source as stereo). Only change this attribute’s value when you understand these settings.

noteNote
If you intend to provide a value other than one the default values listed in the DialogNormalization section below, do not set the NormalizeAudio or AudioGainLevel attributes of the <MediaFile> element.

LoRoCenterMixLevel

This attribute determines the nominal down mix level of the Center channel with respect to Left and Right channels in an Lo/Ro down mix, and takes effect when AudioCodingMode is set to Mode32. The default value recommended by Dolby Laboratories, Inc. is -3.0

LoRoSurroundMixLevel

This attribute determines the nominal down mix level of the surround channel with respect to Left and Right channels in a Lo/Ro down mix, and takes effect when AudioCodingMode is set to Mode32. The default value recommended by Dolby Laboratories, Inc. is -3.0

LtRtCenterMixLevel

This attribute determines the nominal down mix level of the Center channel with respect to Left and Right channels in a Lt/Rt down mix and takes effect when AudioCodingMode is set to Mode32. The default value recommended by Dolby Laboratories, Inc. is -3.0

LtRtSurroundMixLevel

This attribute determines the nominal down mix level of the surround channel with respect to Left and Right channels in a Lt/Rt down mix and takes effect when AudioCodingMode is set to Mode32. The default value recommended by Dolby Laboratories, Inc. is -3.0

NinetyDegreePhaseShiftSurrounds

This attribute determines whether a 90-degree phase-shift filter is applied to the surround channels. The default value is True if Surround channels are present, such as with AudioCodingMode of Mode32. If there are no Surround channels, such as with AudioCodingMode value of Mode20 or Mode10, this attribute must be set to False

ThreeDBAttenuationSurrounds

This attribute determines whether the surround channels should be attenuated by 3dB before encoding. The value should be set to False if the AudioCodingMode does not include surround channels, for example, Mode10 or Mode20. When AudioCodingMode permits surround channels, for example, Mode32, then ThreeDBAttenuationSurrounds may be set to either True or False. The default value recommended by Dolby Laboratories, Inc. is False

noteNote
When AudioCodingMode is set to Mode32 or Mode10, use a value of NotIndicated

SamplesPerSecond

Specifies the number of samples taken per second (the sampling rate). Valid values are 44100 or 48000 kHz.

StereoDownmixPreference

This attribute indicates the preferred type of stereo down mix, and takes effect when AudioCodingMode is set to Mode32. The default value recommended by Dolby Laboratories, Inc. is NotIndicated.

RFModeDynamicRangeControl

This attribute determines the selected heavy dynamic range compression characteristics in RF mode from a set of presets. RF mode is a dynamic range control that reduces the dynamic range of audio content. When compared with line mode music and loud noises sound quieter but voices will sound louder. Care should be taken when setting this attribute. Many things can affect the setting needed including, the loudness of the source, the NormalizeAudio and AudioGainLevel attributes of the <MediaFile> config element, and channel mixing (encoding a stereo source as 5.1 or a 5.1 source as stereo). Only change this attribute’s value when you understand these settings.

noteNote
If you intend to provide a value other than one the default values listed in the DialogNormalization section below, do not set the NormalizeAudio or AudioGainLevel attributes of the <MediaFile> element.

AudioCodingMode Attribute

 

Value Description

Mode20

Stereo (Left, Right) channels

Mode32

5.1 multichannel (Left, Right, Center, LeftSurround, RightSurround, LowFrequencyEffects) channels

Mode10

Mono (Center) channel.

Channels Attribute

 

Value Description

“6”

5.1 Multichannel: left, center, right, left surround, right surround, and low frequency effect (LFE) channels are encoded.

“2”

Stereo: left and right channels are encoded.

“1”

Mono: a single channel is encoded

Codec Attribute

 

Value Description

DolbyDigitalPlus

Use the DolbyDigitalPlus codec

EncoderMode Attribute

 

Value Description

DolbyDigitalPlus

Use the DolbyDigitalPlus encoder mode

DialogNormalization Attribute

 

Value Description

-24

For Advanced Television Standards Committee (ATSC) broadcasting

-23

European Broadcasting Union (EBU) broadcasting

-31

Disc Authoring

DolbySurroundMode Attribute

 

Value Description

NotIndicated

Instructs encoder to not use Dolby Surround Mode. This is the default value.

NotSurroundEncoded

Instructs the encoder to use Dolby Surround Mode, the source is not surround encoded.

SurroundEncoded

Instructs the encoder to use Dolby Surround Mode, the source is surround encoded.

LFELowpassFilter Attribute

 

Value Description

True

The encoder applies a 120 Hz low-pass filter to the LFE channel. This is the default value.

False

The encoder does not apply a 120 Hz low-pass filter to the LFE channel.

LFEOn Attribute

 

Value Description

True

The encoder encodes the Low Frequency Effects (LFE) channel.

False

The encoder does not encode the Low Frequency Effects (LFE) channel.

LineModeDynamicRangeControl Attribute

 

Value Description

None

The encoder uses no line mode dynamic range compression.

FilmStandard

The encoder uses line mode standard dynamic range compression for film. This is the default value.

FilmLight

The encoder uses line mode light dynamic range compression for film.

MusicStandard

The encoder uses line mode standard dynamic range compression for music.

MusicLight

The encoder uses line mode light standard dynamic range compression for music.

Speech

The encoder uses line mode dynamic range compression for speech.

LoRoCenterMixLevel Attribute

 

Value Description

3.0

Indicates a nominal down-level mix of +3.0dB

1.5

Indicates a nominal down-level mix of +1.5dB

0

Indicates a nominal down-level mix of 0dB

-1.5

Indicates a nominal down-level mix of -1.5dB

-3.0

Indicates a nominal down-level mix of -3.0dB - This is the default value

-4.5

Indicates a nominal down-level mix of -4.5dB

-6.0

Indicates a nominal down-level mix of -6.0dB

-Infinity

Indicates a nominal down-level mix of negative infinity

LoRoSurroundMixLevel Attribute

 

Value Description

-1.5

Indicates a nominal down-level mix of -1.5dB

-3.0

Indicates a nominal down-level mix of -3.0dB

-4.5

Indicates a nominal down-level mix of -4.5dB

-6.0

Indicates a nominal down-level mix of -6.0dB

-Infinity

Indicates a nominal down-level mix of negative infinity

LtRtCenterMixLevel Attribute

 

Value Description

3.0

Indicates a nominal down-level mix of +3.0dB

1.5

Indicates a nominal down-level mix of +1.5dB

0

Indicates a nominal down-level mix of 0dB

-1.5

Indicates a nominal down-level mix of -1.5dB

-3.0

Indicates a nominal down-level mix of -3.0dB - This is the default value

-4.5

Indicates a nominal down-level mix of -4.5dB

-6.0

Indicates a nominal down-level mix of -6.0dB

-Infinity

Indicates a nominal down-level mix of negative infinity

LtRtSurroundMixLevel Attribute

 

Value Description

-1.5

Indicates a nominal down-level mix of -1.5dB

-3.0

Indicates a nominal down-level mix of -3.0dB

-4.5

Indicates a nominal down-level mix of -4.5dB

-6.0

Indicates a nominal down-level mix of -6.0dB

-Infinity

Indicates a nominal down-level mix of negative infinity

NinetyDegreePhaseShiftSurrounds Attribute

 

Value Description

True

A 90-degree phase-shift filter is applied to the surround channels.

False

A 90-degree phase-shift filter is not applied to the surround channels.

ThreeDBAttenuationSurrounds Attribute

 

Value Description

True

The surround channels will be attenuated by 3dB before encoding.

False

The surround channels will not be attenuated by 3dB before encoding

StereoDownmixPreference Attribute

 

Value Description

NotIndicated

No stereo down-mix will be performed

ProLogicLtRt

Stereo down-mix will be performed generating ProLogic right and left channels

StereoDownmixLoR

Stereo down-mix will be performed generating a mono channel.

ProLogicII

Stereo down-mix will be performed generating ProLogicII right and left channels

RFModeDynamicRangeControl Attribute

 

Value Description

None

The encoder uses no RF mode dynamic range compression.

FilmStandard

The encoder uses RF mode standard dynamic range compression for film. This is the default value.

FilmLight

The encoder uses RF mode light dynamic range compression for film.

MusicStandard

The encoder uses RF mode standard dynamic range compression for music.

MusicLight

The encoder uses RF mode light standard dynamic range compression for music.

Speech

The encoder uses RF mode dynamic range compression for speech.

Child Elements

 

Element Description

<BitRate>

Contains a <ConstantBitrate> element that specifies the average bitrate of the encoded Dolby Digital Plus stream.

Parent Elements

 

Element Description

<AudioProfile>

Root element of an audio profile

The following table shows the allowed bit ranges for the different AudioCoding modes.

 

AudioCodingMode Allowed Range of bitrate (kbps) as specified in the <Bitrate>/<ConstantBitrate> child element

Mode10

32 - 3,024

Mode20

96 - 3,024

Mode32

192 - 3,024

Within the above bit ranges, the Bitrate attribute can only be set to one of the following values:

32, 48, 56, 64, 72, 80, 88, 96, 104, 112, 120, 128, 144, 160, 176, 192, 200, 208, 224, 232, 240, 248, 256, 272, 288, 300, 320, 336, 352, 368, 384, 400, 448, 512, 576, 640, 704, 768, 832, 896, 960, 1008, 1024, 1152, 1280, 1408, 1512, 1536, 1664, 1792, 1920, 2048, 2176, 2304, 2432, 2560, 2688, 2816, 2944, 3024

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