[FFmpeg-devel] [PATCH] wmapro decoder

Sascha Sommer saschasommer
Wed Sep 2 20:15:45 CEST 2009


Hi,

On Mittwoch, 2. September 2009, Vitor Sessak wrote:
> Sascha Sommer wrote:
> > Hi,
> >
> > On Dienstag, 1. September 2009, Michael Niedermayer wrote:
> >> On Mon, Aug 31, 2009 at 09:55:25PM +0200, Sascha Sommer wrote:
> >>> Hi,
> >>>
> >>>>> +    uint32_t         frame_num;                     ///< current
> >>>>> frame number
> >>>>
> >>>> unused
> >>>
> >>> It is used for error output and some debugging messages. Does it waste
> >>> too many resources?
> >>
> >> no, but fields of structs that are unused in the decoding process should
> >> be documented as such IMHO
> >
> > Done.
> >
> >>>>> +            /** save transmitted scale factors so that they can be
> >>>>> reused for +                the next subframe */
> >>>>> +            memcpy(s->channel[c].saved_scale_factors,
> >>>>> +                   s->channel[c].scale_factors, s->num_bands *
> >>>>> +                   sizeof(*s->channel[c].saved_scale_factors));
> >>>>
> >>>> what happens with s->channel[c].scale_factors so that it cant just be
> >>>> used?
> >>>
> >>> The saved scale factors might be resampled for several subframes before
> >>> some new values are transmitted and saved_scale_factors is updated.
> >>> If the resampled scale factors would be used for the resampling, the
> >>> output would change. Therefore two buffers are needed.
> >>
> >> understood, please document this though, also isnt it possible to just
> >> exchange 2 pointers instead of a memcpy?
> >
> > I documented it. Is the attached pointer exchange code ok or did you have
> > something different in mind?
> >
> >> [..]
> >>
> >>> New patch attached...
> >>
> >> except above, iam ok with the patch
> >
> > Ok. Commited with the mentioned changes.
> >
> > Thanks to you and everyone else who helped me to get this code into SVN.
>
> Great! Patch to ffmpeg.org/trunk/src/index missing ;)
>

If someone wants to write an entry please wait until the MAX_AUDIO_FRAMESIZE 
change is discussed. Without this change the code will fail on many 
multichannel files afaik.

Regards

Sascha



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