Fix #534: Bug in user-defined scaling list

This change sets isAllDefault to false, if there is one list, that is not equal. So this seems correct.

But later we have:

return !isAllDefault;

While the comment says:

"returns true if use default quantization matrix in all size"

So either the return or the comment is wrong.

Btw, I also think checkDefaultScalingList is not a good name, because as user of the function I would nor know, what the bool return value is supposed to be. Also the function does not check the default list, it is comparing some input to the default list. isDefaultScalingList or isEqualToDefaultScalingList may be better.

added 1 commit

• fb96c2bf - Update fix #534

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Thank you for the comments. I have updated the function name and comment in the source code accordingly.

merged

mentioned in commit 6a160c04

I understand that these messages are correct

Slice.cpp:2001:23: warning: 'int __builtin_memcmp_eq(const void*, const void*, long long unsigned int)' reading 256 bytes from a region of size 64 [-Wstringop-overflow=]
 2001 |       if( !( !::memcmp(getScalingListAddress(sizeId, listId), getScalingListDefaultAddress(sizeId, listId), sizeof(int)*std::min(MAX_MATRIX_COEF_NUM, (int)g_scalingListSize[sizeId])) // check value of matrix
      |               ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Slice.cpp:2001:23: warning: 'int __builtin_memcmp_eq(const void*, const void*, long long unsigned int)' reading 256 bytes from a region of size 64 [-Wstringop-overflow=]
Slice.cpp:2001:23: warning: 'int __builtin_memcmp_eq(const void*, const void*, long long unsigned int)' reading 256 bytes from a region of size 64 [-Wstringop-overflow=]
Slice.cpp:2001:23: warning: 'int __builtin_memcmp_eq(const void*, const void*, long long unsigned int)' reading 256 bytes from a region of size 64 [-Wstringop-overflow=]
Slice.cpp:2001:23: warning: 'int __builtin_memcmp_eq(const void*, const void*, long long unsigned int)' reading 256 bytes from a region of size 64 [-Wstringop-overflow=]
Slice.cpp:2001:23: warning: 'int __builtin_memcmp_eq(const void*, const void*, long long unsigned int)' reading 256 bytes from a region of size 64 [-Wstringop-overflow=]
Slice.cpp:2001:23: warning: 'int __builtin_memcmp_eq(const void*, const void*, long long unsigned int)' reading 256 bytes from a region of size 64 [-Wstringop-overflow=]
Slice.cpp:2001:23: warning: 'int __builtin_memcmp_eq(const void*, const void*, long long unsigned int)' reading 256 bytes from a region of size 64 [-Wstringop-overflow=]

Sorry, I will check it.

This warning has not occurred in my linux and windows environments. I think this warning depends on the gcc version and it is independent of this bugfix. Unfortunately, I have no way to reproduce this warning.

I use version GCC 9.2.1

http://msystem.waw.pl/x265/

http://msystem.waw.pl/x265/mingw-gcc921-20190824.7z

I add open source VVC codec:

https://www.sendspace.com/file/6717fn

Maybe

      if ( ::memcmp(getScalingListAddress(sizeId, listId), getScalingListDefaultAddress(sizeId, listId), sizeof(int)*std::min(MAX_MATRIX_COEF_NUM, (int)g_scalingListSize[sizeId])) // check value of matrix
         && !( (sizeId < SCALING_LIST_16x16) || (getScalingListDC(sizeId,listId) == 16) ) ) // check DC value

Thank you for informing me. I will try it.

I have confirmed that your suggestion solves this error without any issues. I have created new merge request as following; !974 (merged)

mentioned in merge request !974 (merged)

mentioned in commit 5fe4d7f5