[theora] NHW Image codec

[Raphael Canut]

Hello,

I don't have advanced (and worked) on the NHW codec recently.I however
compiled the codec with gcc -O3 setting (the binaries are available from my
demo page: http://nhwcodec.blogspot.com ) and just with this optimization
(no mmx, sse, avx instructions,... ) the NHW codec is 6x faster to encode
and 4x faster to decode than WebP.As I state that my codec is royalty-free,
fast with more neatness, these are good speed numbers.

For the neatness, I didn't find a good algorithm to make a neatness
measurement, so the neatness review is still at visual evaluation for now...

For the royalty/patent-free aspect, I remember that I had few months ago
this answer from Ralph Giles: "Open source and royalty-free video codec
development are
definitely on-topic for this list." Can this answer mean that I could have
a kind of "guarantee" from Xiph that the NHW codec is royalty-free? Also, I
think there are new processings in the NHW codec, would it be better that I
patent them? Or can I let it unpatented and open-source?

Any feedback is welcome.

Cheers,
Raphael

[Jason Self]

I could have a kind of "guarantee" from Xiph that the NHW codec is
royalty-free?

You probably want a patent attorney which would probably be expensive
and even then, in today's world of broken patent systems, I doubt
you'd get a "guarantee."

[Raphael Canut]

Hello,

Yes, that's right.I still think that it would have more weight if I could
claim that Xiph has reviewed the source code and find that the NHW codec is
royalty/patent-free (better than me alone claiming this...).Maybe it was in
this sense that Ralph Giles answered me?

Cheers,
Raphael

Post by Jason Self

I could have a kind of "guarantee" from Xiph that the NHW codec is
royalty-free?

You probably want a patent attorney which would probably be expensive
and even then, in today's world of broken patent systems, I doubt
you'd get a "guarantee."
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[Basil Mohamed Gohar]

Post by Raphael Canut
Hello,
Yes, that's right.I still think that it would have more weight if I
could claim that Xiph has reviewed the source code and find that the NHW
codec is royalty/patent-free (better than me alone claiming
this...).Maybe it was in this sense that Ralph Giles answered me?
Cheers,
Raphael

That's not a guarantee that anyone can make, not even a patent attorney. The current landscape is such that "being clear of patent concerns" is impossible. Someone can be destroyed by the legal process that results in them being exonerated, but then left with no will nor resources to continue development.

I don't say this to scare you away, just understand that asking Xiph to "clear" the patent issues doesn't make sense. Xiph is a non-profit organization that advances the cause of free, open, and royalty-free technologies, but cannot offer a technically legal service as requested.

[Raphael Canut]

Hello,

Ok, and that's too many work to review a source code.In my codec, I have 3
compression schemes, I think 2 are not patented, but the third... I don't
know.For the rest, I think my codec is patent-free (I don't use
SPIHT,EZW,zerotree methods), even the wavelet transform is new and don't
use the lifting scheme nor the convolution product.

Else, if you found time to review the codec, do not hesitate to let me know
what you think of it and if you would have remarks.Would be much
appreciated.

Cheers,
Raphael

Post by Basil Mohamed Gohar

Post by Raphael Canut
Hello,
Yes, that's right.I still think that it would have more weight if I
could claim that Xiph has reviewed the source code and find that the NHW
codec is royalty/patent-free (better than me alone claiming
this...).Maybe it was in this sense that Ralph Giles answered me?
Cheers,
Raphael

That's not a guarantee that anyone can make, not even a patent attorney.
The current landscape is such that "being clear of patent concerns" is
impossible. Someone can be destroyed by the legal process that results in
them being exonerated, but then left with no will nor resources to continue
development.
I don't say this to scare you away, just understand that asking Xiph to
"clear" the patent issues doesn't make sense. Xiph is a non-profit
organization that advances the cause of free, open, and royalty-free
technologies, but cannot offer a technically legal service as requested.
--
Libre Video
http://librevideo.org
_______________________________________________
theora mailing list
http://lists.xiph.org/mailman/listinfo/theora

[Raphael Canut]

Hello,

So here is the compression scheme that I don't know if is covered by patent.

I use it on the wavelet DC parts.It outputs 1 byte (8 bits) words.There is
5 modes:

- 1(MSB) | 7 bits to store value (0->127 range)
- 01 | 6 bits to store val[n+1]-val[n] | val[n]-val[n-1] if each in the
range [-4,4]
- 001 | 5 bits to store val[n+2]-val[n+1] | val[n+1]-val[n] |
val[n]-val[n-1] if each in range
- 0001 | special case
- 0000 | 4 bits for RLE+prediction

It is a simple compression scheme, it is not as good as context modeling +
arithmetic coding, but it gives good results on my data (wavelet DC parts)
and is very fast.

My question is: Does someone know if this compression scheme is patented?
Also, as it is quite simple, maybe the patent has expired (more than 20
year old)?

Also, if someone knows a better compression scheme for DC parts (not too
complex, I don't want to use context modeling + arithmetic coding for now,
even if I know that patents on arithmetic coding have nearly all expired),
do not hesitate to let me know.

Cheers,
Raphael

Post by Raphael Canut
Hello,
Ok, and that's too many work to review a source code.In my codec, I have 3
compression schemes, I think 2 are not patented, but the third... I don't
know.For the rest, I think my codec is patent-free (I don't use
SPIHT,EZW,zerotree methods), even the wavelet transform is new and don't
use the lifting scheme nor the convolution product.
Else, if you found time to review the codec, do not hesitate to let me
know what you think of it and if you would have remarks.Would be much
appreciated.
Cheers,
Raphael

Post by Basil Mohamed Gohar

Post by Raphael Canut
Hello,
Yes, that's right.I still think that it would have more weight if I
could claim that Xiph has reviewed the source code and find that the NHW
codec is royalty/patent-free (better than me alone claiming
this...).Maybe it was in this sense that Ralph Giles answered me?
Cheers,
Raphael

That's not a guarantee that anyone can make, not even a patent attorney.
The current landscape is such that "being clear of patent concerns" is
impossible. Someone can be destroyed by the legal process that results in
them being exonerated, but then left with no will nor resources to continue
development.
I don't say this to scare you away, just understand that asking Xiph to
"clear" the patent issues doesn't make sense. Xiph is a non-profit
organization that advances the cause of free, open, and royalty-free
technologies, but cannot offer a technically legal service as requested.
--
Libre Video
http://librevideo.org
_______________________________________________
theora mailing list
http://lists.xiph.org/mailman/listinfo/theora

[Raphael Canut]

Hello,

Yes, the next step for this compression scheme is to make it adaptive, more
rle for plain regions, more differential coding for high contrast.I could
start for example by decomposing the wavelet DC image in 16x16 blocks and
giving 4 modes to each block: 1) plain (blank) block, more RLE, 2) high
contrast, edges, more differential coding, 3) mid, current scheme, 4)
texture, grain.As in the current state this scheme gives pretty good
results on wavelet DC parts, this could be even better.

Else, I'm slowly working again on the NHW codec.I would like to code the
lower quality settings (-l3 and below, high compression) but it seems hard
with my algorithm and HEVC intra is doing very well in this domain.On the
contrary, for mid/normal compression (-l2 to -h3 setting), I prefer the NHW
codec to HEVC because it has more neatness, I also prefer in this range
Daala codec because of its grain and precision.

Would it be possible to create a codec only for mid/normal compression (and
upper quality)? Is there a niche for this kind of codec? My codec will be
still royalty-free and very fast.

Cheers,
Raphael

Post by Raphael Canut
Hello,
So here is the compression scheme that I don't know if is covered by patent.
I use it on the wavelet DC parts.It outputs 1 byte (8 bits) words.There is
- 1(MSB) | 7 bits to store value (0->127 range)
- 01 | 6 bits to store val[n+1]-val[n] | val[n]-val[n-1] if each in the
range [-4,4]
- 001 | 5 bits to store val[n+2]-val[n+1] | val[n+1]-val[n] |
val[n]-val[n-1] if each in range
- 0001 | special case
- 0000 | 4 bits for RLE+prediction
It is a simple compression scheme, it is not as good as context modeling +
arithmetic coding, but it gives good results on my data (wavelet DC parts)
and is very fast.
My question is: Does someone know if this compression scheme is patented?
Also, as it is quite simple, maybe the patent has expired (more than 20
year old)?
Also, if someone knows a better compression scheme for DC parts (not too
complex, I don't want to use context modeling + arithmetic coding for now,
even if I know that patents on arithmetic coding have nearly all expired),
do not hesitate to let me know.
Cheers,
Raphael

Post by Raphael Canut
Hello,
Ok, and that's too many work to review a source code.In my codec, I have
3 compression schemes, I think 2 are not patented, but the third... I don't
know.For the rest, I think my codec is patent-free (I don't use
SPIHT,EZW,zerotree methods), even the wavelet transform is new and don't
use the lifting scheme nor the convolution product.
Else, if you found time to review the codec, do not hesitate to let me
know what you think of it and if you would have remarks.Would be much
appreciated.
Cheers,
Raphael

Post by Basil Mohamed Gohar

Post by Raphael Canut
Hello,
Yes, that's right.I still think that it would have more weight if I
could claim that Xiph has reviewed the source code and find that the

NHW

Post by Raphael Canut
codec is royalty/patent-free (better than me alone claiming
this...).Maybe it was in this sense that Ralph Giles answered me?
Cheers,
Raphael

That's not a guarantee that anyone can make, not even a patent
attorney. The current landscape is such that "being clear of patent
concerns" is impossible. Someone can be destroyed by the legal process
that results in them being exonerated, but then left with no will nor
resources to continue development.
I don't say this to scare you away, just understand that asking Xiph to
"clear" the patent issues doesn't make sense. Xiph is a non-profit
organization that advances the cause of free, open, and royalty-free
technologies, but cannot offer a technically legal service as requested.
--
Libre Video
http://librevideo.org
_______________________________________________
theora mailing list
http://lists.xiph.org/mailman/listinfo/theora