• 5.12.1. DX_SVMT Overview
• 5.12.2. DX_SVMT Definition
• 5.12.3. DX_SVMT Parameters
• 5.12.4. Default Values in the Speed/Volume Modification Table

5.12. DX_SVMT: Speed/Volume Modification Table

The DX_SVMT data structure contains parameters for the Speed/Volume Modification Table.

5.12.1. DX_SVMT Overview

You can specify the rate of change for speed or volume adjustments by customizing the Speed/Volume Modification Table (SVMT) per channel. The DX_SVMT structure has 21 entries that represent different levels of speed or volume. This structure is used to set or retrieve the SVMT values, using dx_setsvmt( ) or dx_getsvmt( ) respectively.

NOTE:

Although there are 21 entries available in the DX_SVMT structure, all do not have to be utilized for changing speed or volume; the number of entries can be as small as you require. Ensure that you insert -128 (80h) in any entries that do not contain a speed or volume setting.

5.12.2. DX_SVMT Definition

The typedef for the structure is as follows:

    typedef struct DX_SVMT{

       char   decrease[10];       /* Ten Downward Steps */

       char   origin;             /* Regular Speed or Volume */

       char   increase[10];       /* Ten Upward Steps */

    } DX_SVMT;




5.12.3. DX_SVMT Parameters

Field	Description
decrease[10]	Decrease Speed or Volume: This array provides a maximum of 10 downward steps from the normal speed or volume (-8 dB). The size of the steps is specified in this table. The following valid values can be used (specify the null-entry marker for all unused table entries):
	Speed Table	an integer from -1 to -50, representing a percentage decrease from normal.
	Volume Table	an integer from -1 to -30, representing a decibel decrease from normal.
	Both	-128 (80h): the null-entry and end-of-table marker.
origin	Origin: Specifies the standard play speed or volume. This is the original setting or starting point for Speed and Volume Control. Set the origin to 0 to assume normal playback speed/volume for the standard (normal volume is -8 dB).
increase[10]	This array provides a maximum of 10 upward steps from the normal speed or volume. The size of the steps is specified in this table. The following valid values can be used (specify the null-entry marker for all unused table entries):
	Speed Table	an integer from 1 to 50, representing a percentage increase from normal.
	Volume Table	an integer from 1 to -10, representing a decibel increase from normal.
	Both	-128 (80h): the null-entry and end-of-table marker.

5.12.4. Default Values in the Speed/Volume Modification Table

If you use dx_setsvmt( ) to customize the SVMT, the changes are saved permanently. You can obtain the manufacturer's original defaults by specifying SV_SETDEFAULT for the dx_setsvmt( ) function.

Table 3. Default Speed/Volume Modification Table

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