ILMAC3Encoder

This is the interface for the LEAD AC3 Encoder.

Data Types

LEncAC3_APILEVEL

typedef enum  
{ 
   LEncAC3_APILEVEL_1, 
} LEncAC3_APILEVEL; 

Lists the valid values for the ApiLevel parameter that can be passed to the ResetToDefaultsEx method.

LEncAC3_APILEVEL_1 Use the defaults from the current version of the codec.

eAC3OutputChannels

enum 
{ 
   LENCAC3_UNCHANGED = 0, 
   LENCAC3_FORCE_MONO = 1, 
   LENCAC3_FORCE_STEREO = 2, 
   LENCAC3_FORCE_6CHANNELS = 6 
} eAC3OutputChannels; 

Interface Properties:

Type

Name

Description

long

OutputBitrate

Sets the output bitrate of the compressed audio data. The bitrate is the average number of bits that one second of audio data will take up in the compressed bitstream. The bitrate represents the strength of compression. It also influences quality: the higher the bitrate, the higher the quality.

The unit of measure for the bitrate is in kbps. To calculate the number of bytes per second of audio data, divide the bitrate value by eight.

The following bitrate values are valid: {32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384, 448, 512, 576, 640}.

eAC3OutputChannels

OutputChannelsFlag

An enumeration that specifies the number of output channels. The following values are possible:

LENCAC3_UNCHANGED: The number of output channels equals the number of input channels.
LENCAC3_FORCE_MONO:  There is 1 output channel.
LENCAC3_FORCE_STEREO: There are 2 output channels.
LENCAC3_FORCE_6CHANNELS:  There are 6 output channels.

BOOL

SimulateSurround

Enables or disables surround sound simulation. The following values are possible:

TRUE:  Enables surround sound simulation.

FALSE: Disables surround sound simulation. 

This property is used only if the LENCAC3_FORCE_6CHANNELS eAC3OutputChannels value is selected.

long OutputSampleRate

The output sample rate, in samples per second (Hz).

The following values are possible: {32000, 44100, 48000}.

Interface Methods:

HRESULT ResetToDefaultsEx(LEncAC3_APILEVEL ApiLevel);

Parameters

ApiLevel Specifies which defaults should be used by the filter.

Description

Resets the filter to default values. The ApiLevel parameter determines which default values to use. Current applications should set ApiLevel to LEncAC3_APILEVEL_1 = 0. The filter might change in the future and have different properties or default behaviour. Calling this method ensures future versions of the filter will behave the same way as when the application was developed. It is best to call ResetToDefaultsEx(LEncAC3_APILEVEL_1) before you start setting properties and start calling other methods for this interface.

Returns

S_OK if successful, < 0 if an error occurred.

Common error codes:

E_INVALIDARG

The ApiLevel parameter is invalid.

HRESULT ResetToDefaults();

Description

Resets the filter properties to their default values. Calling this method can cause the filter to reconnect its output pin.

The default values are:
ForceOutChannels = LENCAC3_UNCHANGED
SimulateSurround = FALSE
OutputBitrate = 192
OutputSampleRate = 0

Returns

S_OK if successful, < 0 if an error occurred.

Common error codes:

VFW_E_WRONG_STATE

The filter is in the wrong state.

Help Version 20.0.2019.11.25
Products | Support | Contact Us | Intellectual Property Notices
© 1991-2019 LEAD Technologies, Inc. All Rights Reserved.

LEADTOOLS Filters C API Help