ViewCast 2120 manual Setting Explanation

Niagara 2120 User Guide

Setting		Explanation
		6 — RD on I/P frames
		7 — RD on all frames
		8 — RD refinement on I/P frames
		9 — RD refinement on all frames
		10 — QP-RD (requires trellis=2, aq-mode >0)
QuantizerMax		The default setting is 31. This value sets the maximum for the
		quantizer. 51 is the highest quantizer available for use in the
		H.264 specification and is very low quality.
		IMPORTANT! For low bit rates you want to keep constant, it
		is recommended that you use the default setting of 51 and not
	31.
QuantizerMaxDiffBetweenFrames		This value determines the maximum change quantizer
		between two frames. The purpose is to reduce the possibility
		of any large quality jumps in the output video. It is better to
		slow this change over a few frames rather than all at once. 4 is
		good, however if you don’t want to see big jumps in bit rates
		and don’t mind big jumps in quality, you can increase the
		value to 8 or 16.
QuantizerMin		This value sets the minimum quantizer you will ever use. The
		lower the quantizer the closer it is to its input. For most video,
		anything below 10 is perceptually lossless. Anything below the
		default of 8 is definitely lossless.
		IMPORTANT! Raising gpmin higher than its default of 16 is
		strongly discouraged because this could reduce the quality of
		flat background areas of the frame.
QuantizerScaleCompress		The default setting is 0.60. Use this value to trade off the
		number of bits allocated to “expensive” high-motion versus
		“cheap” low-motion frames.
		At one extreme, a setting of 0.0 aims for true constant bit
		rates. Typically with high-motion scenes, this setting tends to
		look bad. If you use low bit rates, however, low motion scenes
		appear perfect but use more bits than needed.
		The other extreme setting of 1.0 aims to achieve constant
		quantization, however this setting throws many bits at high-
		motion scenes, and a lot less at low-motion scenes which can
		cause the bit rate to fluctuate. 0.50 performs well on sports,
		0.60 on action content, while 0.30 works well with news
		broadcasts. 0.2 works well with drama-type movies, soap
		operas, and shows.

ViewCast 85