ILMVorbisEncoder Interface

Interface Properties:

Type

Name

Description

VARIANT_BOOL

EnableQualityFactor

If this property is TRUE, the output will be compressed using a variable byte rate, and the QualityFactor property should be used to control compression. Set this option to TRUE when consistent audio quality and high compression are the top priority.

If this property is FALSE, the output will be compressed at a constant byterate, and the MaximumByteRate, MinimumByteRate and NominalByteRate properties should be used to control compression. This is useful to generate a predictable file size and when an audio file needs to fit a constant bitrate transmission channel. Moreover, the compressed audio file is searchable, and therefore a particular point within the audio stream can be found. For more information on the quality factor and variable byte rate vs. constant byte rate, see the descriptions for the Variable Rate Radio Button, the Constant Rate Radio Button and the Quality Factor drop-down box above.

long

QualityFactor

This property controls the compression ratio when EnableQualityFactor is TRUE. There are 8 quality factors, ranging from "Highest Quality" (which produces the best audio quality and the biggest file size - low compression ratios) to "Smallest Size/Highest Compression" (which produces the smallest file size and the lowest audio quality - high compression ratios). "Quality and Size are equally important" is a good choice to produce very-near-CD-quality audio at roughly 17,500 Byte per second rate (160 Kbps). "Quality is more important than size", with approximately 120kbps gives a smaller file size and significantly better quality than MP3 compression at 128kbps.

long

NominalByteRate

This property contains the value to set as the average/nominal bitrate in bytes per second. It is valid only if the EnableQualityFactor property is FALSE.

For example, for a desired bitrate of 96Kpbs, set this value to 12,000 (= 96,000 / 8).

long

MaximumByteRate

This property contains the value to set as the maximum bitrate in bytes per second. It is valid only if the EnableQualityFactor property is FALSE.

long

MinimumByteRate

This property contains the value to set as the minimum bitrate in bytes per second. It is valid only if the EnableQualityFactor property is FALSE.

long

SamplePerSec

(read only) If the LEAD Vorbis Encoder input pin is connected, this property gets the input audio stream samples per second.

long

Channels

(read only) If the LEAD Vorbis Encoder input pin is connected, this property gets the input  number of channels of the audio stream . 

eVORBISMAXRATE

MaximumInputRate

Limits the Maximum Sample rate of the input stream coming to LEAD Vorbis Encoder. This way it can decrease the sampling rate of the input stream to increase compression.

 So if this property is set to R_11K, then any input audio stream with rate of 11000 (sample/sec) or above will be compressed at 11000 sample/sec but if it is below that value (8000 sample/sec) it will stay like that.

eVORBISMAXCHANNELS

MaximumInputChannels

Use this property to force the input audio stream to have a maximum number of channels.

For example, if this property is set to C_I, no matter whether the input file is stereo or mono the input audio stream will be compressed as mono.

Basically this property should be used to increase the compression of a stereo file by converting it to mono.

VARIANT_BOOL

IsAVIMuxConnected  

(read only) This property returns TRUE if the LEAD Vorbis Encoder output pin is connected to the AVI Mux filter.

eVORBISMAXRATE

enum 
{ 
   R_08K = 1, 
   R_11K = 2, 
   R_22K = 3, 
   R_32K = 4, 
   R_44K = 5, 
   R_48K = 6 
} eVORBISMAXRATE; 

eVORBISMAXCHANNELS

enum 
{ 
   C_1 = 1, 
   C_2 = 2, 
} eVORBISMAXCHANNELS; 

Help Version 19.0.2017.10.19
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