On Thu, Sep 08, 2011 at 09:23:56AM +0200, Kostya Shishkov wrote:
> On Wed, Sep 07, 2011 at 10:08:37PM +0200, Laurent Aimar wrote:
> > See patch.
>
> Last two chunks (zeroing samples_left when end of data is reported) is fine,
> first chunks are a bit suspicious since they hit corner cases. For example,
> what happens if block ends with a run of zeroes? Probably some get_bits_left()
> checks should be for strictly negative, not negative or zero.
There is always a following read.
> @@ -360,9 +367,13 @@ static int wv_get_value(WavpackFrameContext *ctx,
> GetBitContext *gb, int channel
> }
> if(!c->error_limit){
> ret = base + get_tail(gb, add);
> + if (get_bits_left(gb) <= 0)
> + goto error;
> }else{
> int mid = (base*2 + add + 1) >> 1;
> while(add > c->error_limit){
> + if(get_bits_left(gb) <= 0)
> + goto error;
> if(get_bits1(gb)){
> add -= (mid - base);
> base = mid;
I assume only this part was being criticised about. In this case, the
original code is:
if(!c->error_limit){
ret = base + get_tail(gb, add);
}else{
int mid = (base*2 + add + 1) >> 1;
while(add > c->error_limit){
if(get_bits1(gb)){
add -= (mid - base);
base = mid;
}else
add = mid - base - 1;
mid = (base*2 + add + 1) >> 1;
}
ret = mid;
}
sign = get_bits1(gb);
where a bit is always read at least after the code I changed,
so <= is the right test IMHO.
--
fenrir
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