[Ffmpeg-devel] Differences between mencoder and ffmpegwhenencoding using x264

Robert Swain robert.swain
Tue Feb 21 12:40:48 CET 2006

On Tuesday 21 February 2006 11:27, Erik Slagter wrote:
> On Tue, 2006-02-21 at 10:59 +0000, Robert Swain wrote:
> > Because of the way defaults are handled and because of the sharing of
> > parameters this isn't easily possible. You don't know whether an option
> > has been set by the user or internally and so can't decide whether to set
> > the parameter or not, which implies you have to always set it, which then
> > leads to using default parameters that are suboptimal. Hence why I
> > suggested continuing an earlier discussion about presets for each codec.
> In case of -loop, would it be acceptable to change the global default to
> "on"? It seems this is the biggest issue...
> Also there some options h264-specific, imho these also can be set to
> saner defaults without doing harm to other codecs?!

No need to shout. ;) I agree that there probably isn't any harm in setting the 
h.264-specific parameters to saner defaults. My intent when updating the 
interface was to deal with all the defaults at a later date and just not 
bother with any of them initially. The main priority was to at least enable 
all current functionality at the time as hardly any options were available.

I don't think always enabling loop will be acceptable, I don't know. I 
suggested that flag type options should be capable of -loop 1 to enable and 
-loop 0 to disable and I was informed that -flags +loop and -flags -loop are 
analogous. (To use loop as an example...) This would require either 
documentation or internal code knowledge.

In my opinion the defaults system should be altered such that defaults can be 
specified for each codec. Maybe inheriting defaults from elsewhere and 
overwriting some as required. Defaults should also be consolidated as they're 
all over the place (in the code) at the moment.

This is all my lowly opinion. :) The big guns might disagree. (Michael? Loren? 
Mans? ...Rich? etc :) )


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