Reference Frames option doesn't make a difference

[cribber]

I tried a quick encode with (NVENC) 4 reference frames and 1 reference frame and couldn't see any difference, exactly the same File Info (and still NOT variable bitrate).

I tried using more than 4 reference frames and the conversion failed and asked me if I wanted to disable GPU acceleration.

I tried various reference frames with NVCUVENC and no matter what you select it defaults at 2 reference frames (even if you select 1) but is variable bitrate.

I can't seem to trust any of the settings as they don't do what they're supposed to do. I'm not even sure any of the advanced options work (in custom profile) when using NVENC, I can't be bothered to keep testing them. Maybe NVENC needs a complete rewrite.

[cedric]

Please post your log files and your custom profile.
NVENC don't need to be rewrited, but just need to be tuned...

It works on our test graphic cards here, but it seems that some settings are not used on some others...

Will investigate more with your log/custom profile...

Thank you for your patience

[cribber]

Please post your log files and your custom profile.
NVENC don't need to be rewrited, but just need to be tuned...

It works on our test graphic cards here, but it seems that some settings are not used on some others...

Will investigate more with your log/custom profile...

Thank you for your patience ;)

[cedric]

Thank you, will try to reproduce tomorrow...
have you tried quicksync with last beta?

Regards,

[cribber]

Thank you, will try to reproduce tomorrow...
have you tried quicksync with last beta?

Regards,

I posted about that here :-
http://forums.vso-software.fr/quicksync ... tml#p91404

Can you also check why NVENC is not using variable bitrate.

[cedric]

Why do you said NVENC produce CBR?
All my files converted using NVENC are VBR.
Do you used the last beta version?

Regards,

[cribber]

Why do you said NVENC produce CBR?
All my files converted using NVENC are VBR.
Do you used the last beta version?

Regards,

Yes I am using the latest beta v1.5.0.9. I am using the profile I posted above.

NVENC CRF (according to encoded MediaInfo) is not using variable bitrate.

NVCUVENC CRF encoded MediaInfo tells me :-
Bitrate Mode: Variable
Bitrate:
Maximum Bitrate:

[cedric]

Hello cribber,

I done some tests using NVENC, and for sure the encoded files are VBR...
Do you see a line like "Bit rate mode: Constant" in MediaInfos?
Or are you assuming if "Bit rate mode: Varibale" is not displayed in MediaInfos the video is encoded as CBR?
The only one field where I can see "constant" is: "Frame rate mode: Constant" so, nothing to do with bitrate.

What can you see when playing the converted file in VLC using "Tools", "Codec informations", "Statistics" tab?
Do you see a fixed bitrate value?

For the reference frames setting, I found that neither hardware encoder is able to encode using more than 4 ref frames.
NVCUVENC always use 2 ref frames when NVENC and QuickSync fail when ref frames > 4. (setting now limited in hardware encoders)
It's a device limitation and we can't change this...
I added this information in custom profile hint.

Last point, I can confirm that some settings are not taken in account by hardware encoders (that's why choosing superfast or slower presets gives same framerate)
So, I will investigate more tommorow, I will post my results...

Regards,

Regards,

[cribber]

What I was trying to explain to you was this, I don't use VLC, I use a utility called "MediaInfo".

Using the same small clip for both encodes

When I encode a clip with NVCUVENC and CRF 20 I get these results :-

When I encode a clip with NVENC and CRF 20 I get these results :-

1) So just out of interest, why doesn't the info for the NVENC encode tell me it's variable, average and max bitrate like the NVCUVENC one does ?

2) Why is the NVENC one smaller file size and bitrate ?

3) Why does the NVENC one say 4 reference frames when you said that reference frames don't work with GPU acceleration ? Can you disable all options completely when using GPU acceleration (in custom profile) so you cant alter them please.

4) If reference frames are supposed to work (up to a maximum of 4) then they aren't taking effect because 1,2,3 and 4 reference frames give exactly the same results.

5) I can enable nVidia and Intel QuickSync at the same time, which I should not be able to do.

[cedric]

Hello cribber,

What I was trying to explain to you was this, I don't use VLC, I use a utility called "MediaInfo".

If you read my previous post, I'm using MediaInfo too...?

1) So just out of interest, why doesn't the info for the NVENC encode tell me it's variable, average and max bitrate like the NVCUVENC one does ?

That confirm my previous reply : "Or are you assuming if "Bit rate mode: Varibale" is not displayed in MediaInfos the video is encoded as CBR?"
The video is really in VBR, your real problem is Mediainfo doesn't display the info (and you assumed no info = CBR)
Don't know why MediaInfo doesn't display varibale bitrate info on NVENC file, can check if I can add some additional metadatas...

2) Why is the NVENC one smaller file size and bitrate ?

-> because NVENC is more effective!
I hope that you are not like a lot of users thinking "bigger is my file, better is the video quality"
Please, stay focused on video quality and forget the filesize (especially as I think your NVENC smaller result can have better quality!)

3) Why does the NVENC one say 4 reference frames when you said that reference frames don't work with GPU acceleration ? Can you disable all options completely when using GPU acceleration (in custom profile) so you cant alter them please.

I never said that references frames doesn't work with hardware encoder?
"For the reference frames setting, I found that neither hardware encoder is able to encode using more than 4 ref frames.
NVCUVENC always use 2 ref frames when NVENC and QuickSync fail when ref frames > 4. (setting now limited in hardware encoders)"
So, reference frames will be from 1 to 4 for NVENC and QuickSync, always 2 for NVCUVENC

Can you disable all options completely when using GPU acceleration (in custom profile) so you cant alter them please.

Why should I disable all advanced options when only one is not/partially taken in account? All other advanced options are used.
I don't want to disable them because hardware encoding is a separate option from custom profile, and custom profile edition must be generic.

5) I can enable nVidia and Intel QuickSync at the same time, which I should not be able to do.

No you can't, but I assume that option is not clear...
Internally, the hardware encoders priority are : QuickSync, NVENC, NVCUVENC.
That mean if QuickSync is unchecked, NVENC is used. If NVENC is unchecked, NVCUVENC is used. If NVCUVENC is unchecked, H264 software encoding is used.
I will clarify this option for next version...

Regards,

[cribber]

Hello cribber,

2) Why is the NVENC one smaller file size and bitrate ?

-> because NVENC is more effective!
I hope that you are not like a lot of users thinking "bigger is my file, better is the video quality"
Please, stay focused on video quality and forget the filesize (especially as I think your NVENC smaller result can have better quality!)

I just assumed that they would be roughly the same size because they are both just nVidia Acceleration.

3) Why does the NVENC one say 4 reference frames when you said that reference frames don't work with GPU acceleration ? Can you disable all options completely when using GPU acceleration (in custom profile) so you cant alter them please.

I never said that references frames doesn't work with hardware encoder?
"For the reference frames setting, I found that neither hardware encoder is able to encode using more than 4 ref frames.
NVCUVENC always use 2 ref frames when NVENC and QuickSync fail when ref frames > 4. (setting now limited in hardware encoders)"
So, reference frames will be from 1 to 4 for NVENC and QuickSync, always 2 for NVCUVENC

Yes but there is no difference at all when using NVENC and 1,2,3 or 4 reference frames, as I said a couple of times.

Can you disable all options completely when using GPU acceleration (in custom profile) so you cant alter them please.

Why should I disable all advanced options when only one is not/partially taken in account? All other advanced options are used.
I don't want to disable them because hardware encoding is a separate option from custom profile, and custom profile edition must be generic.

I meant just disable the ones that won't make any effect with NVENC selected.
[/quote]

[cribber]

Why do you completely ignore my posts all the time ? Did you even check the reference frames ?

[cedric]

Why do you completely ignore my posts all the time ? 

Are you serious?
I always take the time to anwer to your posts!!!

Your last first problem is the ref frames (why did you said this setting do nothing, is your nvenc encoded file is always staying to 2 or are they limited to 4?)
You must understand that if ref frame setting is not taken in account, it s not a video converter problem because the value is requested but ignored by graphic card api...

The last problem was the encoding speed and, if you read the log of last beta version, we worked hard on and the encoding speed should be faster (from 90 to 150 on my graphic card)

Do you use another converter program able to use more than 4 ref frames using nvenc?

Regards,

[cribber]

Why do you completely ignore my posts all the time ? 

Are you serious?
I always take the time to anwer to your posts!!!

Well, there were a couple of posts that you never replied to in this forum.

Your last first problem is the ref frames (why did you said this setting do nothing, is your nvenc encoded file is always staying to 2 or are they limited to 4?)
You must understand that if ref frame setting is not taken in account, it s not a video converter problem because the value is requested but ignored by graphic card api...

I asked you this because I've converted a few files with 2 reference frames and 4 reference frames and they are exactly the same to the byte (using NVENC). I tried with software and you can see a difference in the MediaInfo. I just wanted the programmer to confirm if it does or doesn't work with NVENC, because I confirm it doesn't several times now.

The last problem was the encoding speed and, if you read the log of last beta version, we worked hard on and the encoding speed should be faster (from 90 to 150 on my graphic card)

Do you use another converter program able to use more than 4 ref frames using nvenc?

Regards,

Thanks for finally managing to increase the encode speed.

[Copnm]

Hello cribber,

...I've converted a few files with 2 reference frames and 4 reference frames and they are exactly the same to the byte (using NVENC). I tried with software and you can see a difference in the MediaInfo. I just wanted the programmer to confirm if it does or doesn't work with NVENC, because I confirm it doesn't several times now.

It has been proven that "software" (which is still hardware, just not with the graphic card) encoding is more efficient than "hardware" encoding. The CPU's algorithm is better designed to handle such tasks, hence the reason why Handbrake, the staple for video converting, has not added that option to its program. There have been posts on their forums regarding it. "Hardware" encoding is just inefficient in general.

Thanks for reading,
Neil M

[cribber]

Hello cribber,

...I've converted a few files with 2 reference frames and 4 reference frames and they are exactly the same to the byte (using NVENC). I tried with software and you can see a difference in the MediaInfo. I just wanted the programmer to confirm if it does or doesn't work with NVENC, because I confirm it doesn't several times now.

It has been proven that "software" (which is still hardware, just not with the graphic card) encoding is more efficient than "hardware" encoding. The CPU's algorithm is better designed to handle such tasks, hence the reason why Handbrake, the staple for video converting, has not added that option to its program. There have been posts on their forums regarding it. "Hardware" encoding is just inefficient in general.

Thanks for reading,
Neil M

Yes we all know that, you just stated the obvious. You haven't read the thread properly. NVENC (GPU acceleration) doesn't use reference frames, Cedric has just altered the metadata to make you think it does (until he finally bothers to look into it).

[cedric]

I change metadata to simulate false ref frames really? How can you say that (it's totally false...)
For your information, ref frames is not a simple metadata field...
Like I said, I request a ref frame count to nvenc then encoder do what it can.
My nvenc card can't use more than 4 ref frames (I never said that ref frames doesn't works...))

If you don't trust me, you can leave this forum I think...

Bye

[Copnm]

Hello cribber,

You have a very bad attitude. The head programmer of VSO, Cedric, took his time out to sort out what issues you were having and this is how you treat him? I'm surprised he's still responding to you. You're lucky(?) I'm not a mod as you'd no longer have your account or access to the forums.

Thanks for reading,
Neil M

[cribber]

Hello cribber,

You have a very bad attitude. The head programmer of VSO, Cedric, took his time out to sort out what issues you were having and this is how you treat him? I'm surprised he's still responding to you. You're lucky(?) I'm not a mod as you'd no longer have your account or access to the forums.

Thanks for reading,
Neil M

What is your problem ? You've just hijacked this thread with nothing to help.

I have simply asked Cedric whether the reference frames work when using NVENC. He said above that it works up to a maximum of 4 reference frames but the tool tip says it doesn't work with GPU acceleration. I want to know what is the right answer. I've done a lot of testing here and now you've decided to gang up on me ?

[cribber]

I change metadata to simulate false ref frames really? How can you say that (it's totally false...)
For your information, ref frames is not a simple metadata field...
Like I said, I request a ref frame count to nvenc then encoder do what it can.
My nvenc card can't use more than 4 ref frames (I never said that ref frames doesn't works...))

If you don't trust me, you can leave this forum I think...

Bye

I have simply asked you whether the reference frames work when using NVENC. You said above that it works up to a maximum of 4 reference frames but the tool tip says it doesn't work with GPU acceleration. I want to know what is the right answer. I've done a lot of testing here and now I get ganged up on for doing it. Thanks.

Talking of reference frames, when encoding with NO GPU Acceleration with 2 reference frames, the MediaInfo reports it as 4 reference frames ????????????????????????????????????????????????????????????????????????