[Ffmpeg-devel] [PATCH] pointer targets differ in signedness

[Michael Niedermayer]

Hi

On Tue, Sep 12, 2006 at 08:50:01PM +0100, M?ns Rullg?rd wrote:
> Michael Niedermayer <michaelni at gmx.at> writes:
> 
> > Hi
> >
> > On Sun, Sep 10, 2006 at 06:36:16PM +0100, M?ns Rullg?rd wrote:
> >> This patch gets rid of many of the "pointer targets differ in
> >> signedness" warnings generated by gcc4.
> >> 
> >> Please, can those with knowledge of the files listed below check that
> >> I didn't do something stupid?  Needless to say, regression tests pass
> >> with these changes.
> > [...]
> >
> >>      int i;
> >>  
> >>      if(matrix){
> >> Index: libavcodec/mpegvideo.h
> >> ===================================================================
> >> --- libavcodec/mpegvideo.h	(revision 6221)
> >> +++ libavcodec/mpegvideo.h	(working copy)
> >> @@ -344,8 +344,8 @@
> >>      Picture *current_picture_ptr;  ///< pointer to the current picture
> >>      uint8_t *visualization_buffer[3]; //< temporary buffer vor MV visualization
> >>      int last_dc[3];                ///< last DC values for MPEG1
> >> -    int16_t *dc_val_base;
> >> -    int16_t *dc_val[3];            ///< used for mpeg4 DC prediction, all 3 arrays must be continuous
> >> +    uint16_t *dc_val_base;
> >> +    uint16_t *dc_val[3];           ///< used for mpeg4 DC prediction, all 3 arrays must be continuous
> >
> > iam not 100% sure if not maybe some msmpeg4 files had negative dc values
> > maybe it was a bug somewhere else, but as all coeffs are signed 16bit id
> > leave the dc stuff signed too just MHO
> 
> Those pointers are assigned to uint16_t * pointers, which are used for
> actual computations, so I assumed that unsigned was correct.  

well, if you are brave change it to unsigned, if nothing breaks i wont
complain, OTOH if something does break, expect to drink a few 1000 liter
cola :)


> How would the dc values end up negative anyway?

predictor + signed value from bitstream

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

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