H.264 - Codec / Quantizers

Minimum Quantizer

Sets the minimum quantizer.

Maximum Quantizers

Sets the maximum quantizer.

Maximum Quantizers Delta

Sets the maximum change in quantizer between two frames.

IP Ratio

Modifies the target average increase in quantizer for I-frames as compared to P-frames. Higher values increase the quality of I-frames generated

PB Ratio

Modifies the target average decrease in quantizer for B-frames as compared to P-frames.
Higher values decrease the quality of B-frames generated.
Not used with mbtree (enabled by default), which calculates the optimum value automatically.

Chroma QP Offset

Add an offset to the quantizer of chroma planes when encoding.

Inter luma quantization deadzone

Set the size of the inter luma quantization deadzone.
Deadzones should be in the range of 0 to 32.

Intra luma quantization deadzone

Set the size of the intra luma quantization deadzone.
Deadzones should be in the range of 0 to 32.

AQ Mode (Adaptive Quantization Mode)

Without AQ, x264 tends to underallocate bits to less-detailed sections.
AQ is used to better distribute the available bits between all macroblocks in the video.

AQ Strength (Adaptive Quantization Strength)

Sets the strength of Adaptive Quantization bias towards low detail ('flat') macroblocks.