The LEAD AMR Encoder Also known as compressor, this is a module or algorithm to compress data. Playing that data back requires a decompressor, or decoder.compressor Also known as an encoder, this is a module or algorithm to compress data. Playing that data back requires a decompressor, or decoder., this is a module or algorithm to compress data. Playing that data back requires a decompressor, or decoder. is a DirectShow Ò filter for compressing audio data using the AMR speech compression. The AMR speech coder consists of the multi-rate speech coder, a source controlled rate scheme including a voice activity detector and a comfort noise generation system, and an error concealment mechanism to combat the effects of transmission errors and lost packets.
The multi-rate speech coder is a single integrated speech codec A COmpressor combined with a DECompressor, or encoder and a decoder, which allows you to both compress and decompress that same data. with eight source rates from 4.75 kbps to 12.2 kbps, and a low rate background noise encoding mode. The speech coder is capable of switching its bit-rate every 20 ms speech frame upon command.
The LEAD AMR Encoder property page provides a user interface for changing the filter's attributes. The property page is shown in the following figure:
Changes will be applied directly to the streaming media with the ability to set them permanently by clicking Apply or OK, or to abandon changes by clicking Cancel. Positioning the mouse pointer over a control displays general information for that control. The following table shows the controls and their descriptions:
Control |
Description |
|
Bit Rate Drop-down list box |
The desired output bit rate (kbps). Possible values are: |
|
|
|
4.75 |
|
|
5.15 |
|
|
5.90 |
|
|
6.70 |
|
|
7.40 |
|
|
7.95 |
|
|
10.20 |
|
|
12.20 |