[XviD-devel] Request for ideas/comments about 2pass

Edouard Gomez ed.gomez at free.fr
Mon May 26 22:27:26 CEST 2003


Edouard Gomez (ed.gomez at free.fr) wrote:
> 1. in  my   very  humble  (but  rationale)   opinion,  bquant_ratio  and
> bquant_offset should  be part of RC  plugins.  RC plugins  should be the
> only ones which have to know about these parameters. This is logic if we
> think about RC plugins as "best quantizer finding" plugins.

This is a 5min hack, not worth loosing time on this. I have something
ready for that. Just in case you agree with this conclusion.

> 2. Another remark,  min/max_quant[] arrays have been moved  from each RC
> to the xvid_enc_create_t structure. But  encoder is never using them, it
> only serves  them to _all_  RC plugins. I  think the reason  behind this
> move  is that  these max_min_quant[]  arrays have  to be  shared  by all
> plugins (tell me if i did not get the point). But imo, they are not part
> of the encoder. I have a nicer way to manage the sharing problem.
>  - put back quant limitations in _each_ plugin. 
>  - plugins are responsible  of updating the data>max/min_quants arrays
>    with more restrictive values during plugin creation. (max{min_quants}
>    and min{max_quants})

Another 5 min hack... ready too.

> This way, we don't pollute the encoder creation API with parameters that
> are not really part of it.
> 
> 3.we should add a NO_DYNAMIC_FRAMETYPE_DECISION flag so two pass algorithms
> work as expected and are not fooled by the encoder internals.

For simplicity  reasons, i  removed all alt  curv stuff from  my working
tree and i just found we were simply not setting the frame type... dooh.
So it's ok now for frame type decision. (this lack of frame type setting
comes from the fact pete adapted my previous vfw port that has separated
both get_quant and  get_type operations, pete, you just  forgot to perge
them back :-) )

I'm still trying to find a better scaling for bframes, i'm really close
to find... i hope to finish soon.

-- 
Edouard Gomez-------------- next part --------------
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