Edit

Share via

VIDEOENCODER_BITRATE_MODE enumeration (ksmedia.h)

  • Article

The VIDEOENCODER_BITRATE_MODE enumeration describes the bit rate encoding modes supported by the device.

Syntax

typedef enum {
  ConstantBitRate,
  VariableBitRateAverage,
  VariableBitRatePeak
} VIDEOENCODER_BITRATE_MODE;

Constants

 
ConstantBitRate
Specifies that the encoding bit rate is constant.
VariableBitRateAverage
Specifies that the encoding bit rate is variable, with the specified bit rate used as a guaranteed average over a specified window. The default window size is considered to be 5 minutes. That is, this guarantees that the average bit rate over the window period (5 minutes) will not exceed that specified in ENCAPIPARAM_BITRATE.
VariableBitRatePeak
Specifies that the encoding bit rate is variable with the specified bit rate used as an average with a peak not to exceed the specified peak bit rate over a specified window. The default window size is considered to be 500ms (classically one GOP). That is, this bit rate is "constant quality" − the bit rate is expected to average around ENCAPIPARAM_BITRATE but may spike above this. It cannot exceed the bit rate specified in ENCAPIPARAM_PEAK_BITRATE.

Remarks

For all three modes, ENCAPIPARAM_BITRATE must be set to the expected average bit rate over a 5 minute period.

When VariableBitRatePeak mode is used, the ENCAPIPARAM_PEAK_BITRATE must also be set to the peak bit rate, which the VBR encoder must not exceed over a 500ms period (typically one GOP for MPEG-2 video).

Requirements

Requirement Value
Header ksmedia.h (include Ksmedia.h)

See also

ENCAPIPARAM_BITRATE

ENCAPIPARAM_BITRATE_MODE

ENCAPIPARAM_PEAK_BITRATE