MRV
Posts: 28
Joined: Thu Jul 19, 2018 3:09 am

Max resolution for stereo?

Thu Jan 16, 2020 1:34 pm

Hello.

We are using a Compute Module 3+ attached to a custom carrier board with two cameras - this allows for the acquisition of stereo imagery using Raspivid. Currently we are restricted to 1920 x 1080 encoding. Is there a way, either on PI3+ or PI4, to increase this size to at least 2048 x 1024?

Thanks.

6by9
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Re: Max resolution for stereo?

Thu Jan 16, 2020 3:07 pm

No. The codec hardware has an internal line buffer that is of a fixed size.
I had expected it to be 2048 pixels wide to accomodate 2,048×1,024@30.0 that is specified as part of level 4.0, but something goes wrong in the config of the last macroblock column, and (memory says) 2032 is the highest width that works.
Software Engineer at Raspberry Pi Trading. Views expressed are still personal views.
I'm not interested in doing contracts for bespoke functionality - please don't ask.

MRV
Posts: 28
Joined: Thu Jul 19, 2018 3:09 am

Re: Max resolution for stereo?

Thu Jan 16, 2020 3:24 pm

Is 2032 x 1016 possible?
6by9 wrote:
Thu Jan 16, 2020 3:07 pm
No. The codec hardware has an internal line buffer that is of a fixed size.
I had expected it to be 2048 pixels wide to accomodate 2,048×1,024@30.0 that is specified as part of level 4.0, but something goes wrong in the config of the last macroblock column, and (memory says) 2032 is the highest width that works.

6by9
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 7707
Joined: Wed Dec 04, 2013 11:27 am
Location: ZZ9 Plural Z Alpha, aka just outside Cambridge.

Re: Max resolution for stereo?

Thu Jan 16, 2020 3:45 pm

MRV wrote:
Thu Jan 16, 2020 3:24 pm
Is 2032 x 1016 possible?
It should be for simple encode, but won't be for stereoscopic as it doesn't meet the requirement for the width of each image being a multiple of 128.
Software Engineer at Raspberry Pi Trading. Views expressed are still personal views.
I'm not interested in doing contracts for bespoke functionality - please don't ask.

MRV
Posts: 28
Joined: Thu Jul 19, 2018 3:09 am

Re: Max resolution for stereo?

Thu Jan 16, 2020 4:51 pm

Is there an active bug ticket regarding this? (config of the macroblock column)
Would like to see the PI actually being able to get what the level 4 spec says it should. 2048x1024 would be excellent.

[
quote=6by9 post_id=1596450 time=1579189555 user_id=92334]
MRV wrote:
Thu Jan 16, 2020 3:24 pm
Is 2032 x 1016 possible?
It should be for simple encode, but won't be for stereoscopic as it doesn't meet the requirement for the width of each image being a multiple of 128.
[/quote]

6by9
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 7707
Joined: Wed Dec 04, 2013 11:27 am
Location: ZZ9 Plural Z Alpha, aka just outside Cambridge.

Re: Max resolution for stereo?

Thu Jan 16, 2020 5:09 pm

MRV wrote:
Thu Jan 16, 2020 4:51 pm
Is there an active bug ticket regarding this? (config of the macroblock column)
Would like to see the PI actually being able to get what the level 4 spec says it should. 2048x1024 would be excellent.
It's so far down the priorities list I don't think it is being actively tracked - sorry.
You could check for or create an issue at https://github.com/raspberrypi/firmware/issues, but it's not going to boost the priority.

We no longer have developers who know the intimate detail of the codec code, and it may well be the hardware itself that isn't capable of doing it. From extracting the motion vectors we know that we get an extra column of vectors, so it may be the setup there that either requires it or is wrong, but you're probably talking a couple of man days of time to determine if that is the case, and then you need to understand whether that is necessity or accident.
Software Engineer at Raspberry Pi Trading. Views expressed are still personal views.
I'm not interested in doing contracts for bespoke functionality - please don't ask.

MRV
Posts: 28
Joined: Thu Jul 19, 2018 3:09 am

Re: Max resolution for stereo?

Thu Jan 16, 2020 5:17 pm

And the PI3+ and PI 4 both have this issue (limitation)?

6by9 wrote:
Thu Jan 16, 2020 5:09 pm
MRV wrote:
Thu Jan 16, 2020 4:51 pm
Is there an active bug ticket regarding this? (config of the macroblock column)
Would like to see the PI actually being able to get what the level 4 spec says it should. 2048x1024 would be excellent.
It's so far down the priorities list I don't think it is being actively tracked - sorry.
You could check for or create an issue at https://github.com/raspberrypi/firmware/issues, but it's not going to boost the priority.

We no longer have developers who know the intimate detail of the codec code, and it may well be the hardware itself that isn't capable of doing it. From extracting the motion vectors we know that we get an extra column of vectors, so it may be the setup there that either requires it or is wrong, but you're probably talking a couple of man days of time to determine if that is the case, and then you need to understand whether that is necessity or accident.

6by9
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 7707
Joined: Wed Dec 04, 2013 11:27 am
Location: ZZ9 Plural Z Alpha, aka just outside Cambridge.

Re: Max resolution for stereo?

Thu Jan 16, 2020 5:50 pm

MRV wrote:
Thu Jan 16, 2020 5:17 pm
And the PI3+ and PI 4 both have this issue (limitation)?
All versions of the Pi share the same codec block.
Software Engineer at Raspberry Pi Trading. Views expressed are still personal views.
I'm not interested in doing contracts for bespoke functionality - please don't ask.

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