[MPlayer-dev-eng] MEncoder does not duplicate frames correctly

[Arpi]

Hi,

> Arpi writes:
> 
> > Hi,
> >
> > the normal standard way to duplicate (skip) frame in AVi is writting 0 byte
> > length chunks. it means for player: don't decode/display new frame, just
> > wait for next frame...
> 
> Oh, I did not know that.  I'll make a new patch that does it like you
> describe.  Currently it does not do this.  It just duplicate the chunk
> which is plain wrong.

where?

if(skip_flag<0){
    // duplicate frame
    printf("\nduplicate %d frame(s)!!!    \n",-skip_flag);
    while(skip_flag<0){
        aviwrite_write_chunk(muxer,mux_v,muxer_f,0,0);
        ++skip_flag;
    }
} else

it writes N zero-length chunks to the file.

> > Kim Minh wrote:
> >
> >> Another minor tweak is also included: divx4 min_quantizer is set to 1
> >> instead of 2.  Or was there a good reason not to accept 1 as a value?
> >
> > dunno. it's from transcode...
> 
> The documentation from divx4linux-20011010_4.02 says:
> 
>     "When encoding is performed with ENC_OPT_ENCODE, quant and intra
>     fields of ENC_FRAME structure are ignored. Encore2 provides a
>     possibility to more accurately control the encoding process. To
>     use this feature, you have to pass ENC_OPT_ENCORE_VBR as an
>     argument of encore(). In this case, the quant instructs encore to
>     encode the current frame with the specified quantizer. The valid
>     ranges of this field is 1 to 31, with 1 giving highest quality and
>     31 giving lowest bitstream size.  [...]"
> 
> It is not really about min_quantizer, but I get it to also mean that
> the same range is valid...  Should'nt we diverge from transcode where
> it is broken?

of course the range of qscale is 1..31.
but the choosen default values are 2..31, i got it from transcode.
it's still much better than original defaults of divx4linux.

btw, it's config option, if you like 1 is better, add it to conf.


A'rpi / Astral & ESP-team

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