From f24c2e0f56fdcef9b14c4a2ed15c4e9e801bbeab Mon Sep 17 00:00:00 2001 From: Niklas Haas Date: Tue, 20 Jan 2015 20:56:40 +0100 Subject: vo_opengl: always prefer indirect scaling This is better even for non-separable. The only exception is when using bilinear for both lscale and cscale. I've fixed the documentation/comments to make more sense. --- DOCS/man/vo.rst | 23 ++++++++++++++--------- 1 file changed, 14 insertions(+), 9 deletions(-) (limited to 'DOCS/man/vo.rst') diff --git a/DOCS/man/vo.rst b/DOCS/man/vo.rst index 5e03361bf9..f1e69c2b99 100644 --- a/DOCS/man/vo.rst +++ b/DOCS/man/vo.rst @@ -420,17 +420,22 @@ Available video output drivers are: ``no-scale-sep`` When using a separable scale filter for luma, usually two filter - passes are done. This is often faster. However, it forces - conversion to RGB in an extra pass, so it can actually be slower - if used with fast filters on small screen resolutions. Using - this options will make rendering a single operation. - Note that chroma scalers are always done as 1-pass filters. + passes are done, and when using ``cscale`` chroma information is also + scaled separately from luma. This is often faster and better for + most image scalers. However, the extra passes and preprocessing logic + can actually make it slower if used with fast filters on small screen + resolutions. Using this option will make rendering a single operation + if possible, often at the cost of performance or image quality. + + It's safe to enable this if using ``bilinear`` for both ``lscale`` + and ``cscale``. ``cscale=`` - As ``lscale``, but for chroma (2x slower with little visible effect). - Note that with some scaling filters, upscaling is always done in - RGB. If chroma is not subsampled, this option is ignored, and the - luma scaler is used instead. Setting this option is often useless. + As ``lscale``, but for interpolating chroma information. If the image + is not subsampled, this option is ignored entirely. Note that the + implementation is currently always done as a single pass, so using + it with separable filters will result in slow performance for very + little visible benefit. ``lscale-down=`` Like ``lscale``, but apply these filters on downscaling -- cgit v1.2.3