Svt-av1-hdr

[rwill]

Well I am somewhat confused now that I have been thinking about it for a while.

There is this SVT-AV1-HDR file here:

https://github.com/juliobbv-p/svt-av...c/psy_rd.c#L54

Now the author is apparently some "Gianni Rosato" and he licensed it under BSD 2 Clause.

The code seems to be some reinterpretation of x264 code. So much I was aware of.

But looking closer at the comments of some functions, for example:

// in: a pseudo-simd number of the form x+(y<<EW)
// return: abs(x)+(abs(y)<<16)
static inline sum2_t abs2(sum2_t a)
{
    const sum2_t mask = (a >> (BITS_PER_SUM - 1)) & (((sum2_t)1 << BITS_PER_SUM) + 1);
    const sum2_t s = (mask << BITS_PER_SUM) - mask;
    return (a + s) ^ s;
}

This seems too close to x264's

https://code.videolan.org/videolan/x...ype=heads#L255

// in: a pseudo-simd number of the form x+(y<<16)
// return: abs(x)+(abs(y)<<16)
static ALWAYS_INLINE sum2_t abs2( sum2_t a )
{
    sum2_t s = ((a>>(BITS_PER_SUM-1))&(((sum2_t)1<<BITS_PER_SUM)+1))*((sum_t)-1);
    return (a+s)^s;
}

And its not just this one function, its really everywhere.

I sure do hope there are agreements in place with the x264 folks.

Otherwise, well, I am no lawyer, but x264 is licensed under the GPL and SVT-AV1-PSY and on relabeled the code to BSD, maybe a bad call?

Good luck royalty free AV1 enthusiasts.