[rack04]

Originally Posted by moviefan

I thought open-gop gives more efficiency (probably only slightly) so that file sizes decrease. I do not intend to encode Blu-ray compliant streams.

Here are a couple quotes from this thread.

Originally Posted by Trahald

This patch really is only useful if you have small gops (ie bluray) . my tests were at min keyint of 12. This patch is not for your production encodes as it is experimental. Do not create any binaries with this patch that may be in automatic upgrading scripts to protect the innocent.

Originally Posted by Manao

As Trahald already said, this patch is useful mostly when you use a low max keyint interval. The reason for its usefulness is that, without the patch, x264 considers that key frames are IDR, which are special picture types that prevents the previous picture type to be a B frame. So, even if x264 would have wanted to use a B frame, if the following frame must be a key frame because of max keyint, without the patch the B will be transformed into a P frame, which isn't as good.