Options

Enables/Disables use of lossless mode. Default is 0.

For lossy, this is a quality/speed tradeoff. Higher values give better quality for a given size at the cost of increased encoding time. For lossless, this is a size/speed tradeoff. Higher values give smaller size at the cost of increased encoding time. More specifically, it controls the number of extra algorithms and compression tools used, and varies the combination of these tools. This maps to the method option in libwebp. The valid range is 0 to 6. Default is 4.

For lossy encoding, this controls image quality, 0 to 100. For lossless encoding, this controls the effort and time spent at compressing more. The default value is 75. Note that for usage via libavcodec, this option is called global_quality and must be multiplied by FF_QP2LAMBDA.

Configuration preset. This does some automatic settings based on the general type of the image.

'none'

Do not use a preset.

'default'

Use the encoder default.

'picture'

Digital picture, like portrait, inner shot

'photo'

Outdoor photograph, with natural lighting

'drawing'

Hand or line drawing, with high-contrast details

'icon'

Small-sized colorful images

'text'

Text-like