Discussion of CameraConfiguration with extra information: target fps/CaptureIntent

[Cheng-Hao Yang]

Hi Naushir,

On Wed, Oct 23, 2024 at 6:33 PM Naushir Patuck <naush at raspberrypi.com> wrote:
>
> Hi Harvey,
>
> We did look into something similar some years back.  I prototyped a
> patch series introducing stream hints that are entirely options, but
> would provide a way for the applications to hint to the pipeline
> handler what intended use case may be for each stream.  This did not
> get merged, but you can find the series at:
>
> https://patchwork.libcamera.org/project/libcamera/list/?series=3739
>
> Perhaps this is a mechanism to get what you want as well?

IIUC, it's still quite different from what we need in the CL/patch.

I have another patch that adds the use case for a Stream(Configuration):
https://patchwork.libcamera.org/patch/21279/

However, even with the same StreamConfigurations, sometimes it's still
impossible to tell if the app is expecting video with snapshots or StillCapture
use cases, which both contain a Video stream and a StillCapture stream.
This is why we need such information in CameraConfiguration, instead
of in StreamConfiguration only.

BR,
Harvey

>
> Regards,
> Naush
>
> On Wed, 23 Oct 2024 at 09:59, Cheng-Hao Yang <chenghaoyang at chromium.org> wrote:
> >
> > Hi libcamera developers,
> >
> > I found a patch in cros mtkisp7 branch that I don't think you'd like:
> > https://chromium-review.googlesource.com/c/chromiumos/third_party/libcamera/+/5675025/comments/458a308a_be91eda8
> >
> > This patch adds the information in CameraConfiguration that the
> > intention is StillCapture or Preview/Video, which is determined by the
> > target fps in Android adaptor [1]. The information is needed to
> > configure modes in the proprietary libraries.
> >
> > I understand that it doesn't meet the design of CameraConfiguration,
> > but have we considered passing target fps as an argument when doing
> > configuration?
> > I'd also like to know if there are other approaches to satisfy
> > mtkisp7's requirements. Thanks!
> >
> > BR,
> > Harvey
> >
> >
> >
> > [1]: https://source.chromium.org/chromiumos/chromiumos/codesearch/+/main:src/third_party/libcamera/mtkisp7/src/android/camera_device.cpp;l=900