Hi,

On Thu, Feb 23, 2012 at 10:08 AM, Kostya Shishkov
<[email protected]> wrote:
> On Wed, Feb 22, 2012 at 04:49:59PM -0800, Ronald S. Bultje wrote:
>> From: "Ronald S. Bultje" <[email protected]>
>>
>> Fixes crashes for extremely large resizes (several 100-fold).
>>
>> Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
>> CC: [email protected]
>> ---
>>  libswscale/x86/swscale_mmx.c |   38 ++++++++++++++++++++++++++++++++++++++
>>  1 files changed, 38 insertions(+), 0 deletions(-)
>>
>> diff --git a/libswscale/x86/swscale_mmx.c b/libswscale/x86/swscale_mmx.c
>> index 764472e..64d5f0f 100644
>> --- a/libswscale/x86/swscale_mmx.c
>> +++ b/libswscale/x86/swscale_mmx.c
>> @@ -117,6 +117,44 @@ void updateMMXDitherTables(SwsContext *c, int dstY, int 
>> lumBufIndex, int chrBufI
>>          const int16_t **chrUSrcPtr= (const int16_t **) chrUPixBuf + 
>> chrBufIndex + firstChrSrcY - lastInChrBuf + vChrBufSize;
>>          const int16_t **alpSrcPtr= (CONFIG_SWSCALE_ALPHA && alpPixBuf) ? 
>> (const int16_t **) alpPixBuf + lumBufIndex + firstLumSrcY - lastInLumBuf + 
>> vLumBufSize : NULL;
>>          int i;
>> +
>> +        if (firstLumSrcY < 0 || firstLumSrcY + vLumFilterSize > c->srcH) {
>> +            const int16_t **tmpY = (const int16_t **) lumPixBuf + 2 * 
>> vLumBufSize;
>> +            int neg = -firstLumSrcY, i, end = FFMIN(c->srcH - firstLumSrcY, 
>> vLumFilterSize);
>> +            for (i = 0; i < neg;            i++)
>> +                tmpY[i] = lumSrcPtr[neg];
>> +            for (     ; i < end;            i++)
>> +                tmpY[i] = lumSrcPtr[i];
>> +            for (     ; i < vLumFilterSize; i++)
>> +                tmpY[i] = tmpY[i-1];
>
> looks okay, though those tails (;i < vXxxFilterSize; i++) can be optimised
> since they set the same value

This code will soon disappear (once I finish my yasmification), thus
any effort spent on it is pointless.

Ronald
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