what settings are influenced by turbo mode?

[Doom9]

I'm wondering which of all the available settings are influenced when you check turbo mode. I figure VHQ could be a likely candidate, and perhaps motion search precision but I was wondering if anybody could give me the exact rundown of which settings are changed when turbo mode is activated.

[Manao]

The following ME flags are activated when Turbo is checked :

* XVID_ME_FASTREFINE16 : simpler half pel refinement for 16x16 blocks
* XVID_ME_FASTREFINE8 : same thing for 8x8 blocks
* XVID_ME_SKIP_DELTASEARCH : don't search the best direct mode for b-frames.
* XVID_ME_FAST_MODEINTERPOLATE : don't search as thoroughly the bidirectionnal mode in b-frames
* XVID_ME_BFRAME_EARLYSTOP : i don't think that one is used

The first two influence pframes and bframes, the last three only bframes. The first two also change slightly VHQ behavior, though by how much, i can't say.

[Doom9]

I don't suppose those flags can be matched to any of the settings available in the VfW GUI (or mencoder for that matter), can they?

[Manao]

I can't speak for mencoder, but for vfw, these settings can only be enabled by 'Turbo'.

Now, i guess mencoder can give access to those settings as well, since nothing in xvidcore prevents their using.

[Doom9]

I'm afraid mencoder only exposes what the VfW GUI does (plus the chroma optimizer prefilter and hq_ac). So much about my plans for a turbo mode in MeGUI :(

[Manao]

I took a look at mplayer's source code, it seems you can enable the turbo mode by enabling the flag 'turbo'. But you have not to use xvid through libavcodec, it seems.