Hi Baruch,
On Mon, Jul 2, 2018 at 11:57 PM Baruch Siach <baruch at tkos.co.il> wrote:
>
> Hi Tomasz,
>
> On Mon, Jul 02, 2018 at 04:30:52PM +0900, Tomasz Figa wrote:
> > On Mon, Jul 2, 2018 at 4:25 PM Baruch Siach <baruch at tkos.co.il> wrote:
> > > On Fri, May 25, 2018 at 05:52:57PM +0800, JeffyChen wrote:
> > > > On 05/25/2018 02:10 PM, Tomasz Figa wrote:
> > > > > On Thu, May 24, 2018 at 9:18 PM Baruch Siach <baruch at tkos.co.il> wrote:
> > > > > > It looks like only v2 supports h.264 encoding. Does the v2 plugin work
> > > > > > with the rk3288?
> > > > >
> > > > > Hmm, looks like I missed the part about h264 in your original message (only
> > > > > noticed encoding). We didn't have a need to encode h264 on rk3288 devices.
> > > > > The need showed up only later when we were working on rk3399. This made
> > > > > both the driver and plugin for rk3288 lack h264 support.
> > > > >
> > > > > AFAICT the hardware programming interface differs between rk3288 and
> > > > > rk3399, so v2 might not work, but maybe you just need to reshuffle some
> > > > > registers.
> > > > >
> > > > > It's also possible that Rockchip has some code for it. Jeffy, do you know
> > > > > if there is h264 driver code and plugin for rk3288 available somewhere
> > > > > (based on the driver developed for Chrome OS 3.14 kernel)?
> > > >
> > > > well, i do saw a h264e driver for rk3288 in cros kernel:
> > > > chromiumos/src/third_party/kernel/local/drivers/media/platform/rockchip-vpu#
> > > > ls rk3288_vpu_hw_h264e.c
> > > >
> > > > and the related struct defined in v2 plugin:
> > > > libv4l-rockchip_v2/libvepu/common/rk_venc.h:120:struct
> > > > rk3288_h264e_reg_params {
> > >
> > > Thanks for the reference.
> > >
> > > I'm trying to build the v4l plugin stand alone. But in the repo I only see a
> > > Makefile.am file. I guess it integrates with the higher level build system of
> > > CromiumOS.
> > >
> > > Do you have any idea how to build this v4l plugin code stand-alone?
> >
> > It's supposed to be built as a part of v4l-utils
> > (http://git.linuxtv.org/v4l-utils.git), which includes libv4l. We
> > build it with 1.6.0, but I guess newer versions may work too.
> >
> > For reference, here's our ebuild (for Gentoo portage) to build it:
> > https://chromium.googlesource.com/chromiumos/overlays/chromiumos-overlay/+/master/media-libs/libv4lplugins/libv4lplugins-9999.ebuild
>
> The rockchip plugin code refers to the 'config_store' field in v4l2_buffer and
> v4l2_ext_controls. This requires a special version of videodev2.h that is in
> the chromeos-4.4 kernel (featuring commits 3b6d3bc13e572 and 86be552490a2a).
>
> The code of libv4l2 also requires patching since it refers to the 'reserved2'
> field of v4l2_buffer since before version 1.6.0.
>
> I could not find these patches in the libv4l2 ebuild[1]. Where can I find
> them? Is there some other version of libv4l2 that the rockchip plugin builds
> against?
The code is based on Chrome OS kernel headers [1], which are based on
Chrome OS 4.4 kernel [2], which includes some downstream changes.
'config_store' comes from the V4L2 configuration store work in
progress series by Hans Verkuil, which eventually evolved into what we
know today as Request API (still not merged, though). The purpose of
configuration stores was to bind specific V4L2 control values with
particular buffers, since Rockchip encoder needs a number of low level
encoding parameters for every frame [3].
Another caveat is that the encoder API we have implemented in that
driver is just based on hardware registers (excluding the security
sensitive registers, which the driver deals with directly). The plugin
generates registers values and the driver just writes them to the
hardware. This needs to be replaced with a proper stateless encoder
API, based on Request API, which we're working on.
[1] https://chromium.googlesource.com/chromiumos/overlays/chromiumos-overlay/+/master/sys-kernel/linux-headers/linux-headers-4.4.ebuild
[2] https://chromium.googlesource.com/chromiumos/third_party/kernel/+/chromeos-4.4/
[3] https://chromium.googlesource.com/chromiumos/third_party/kernel/+/chromeos-4.4/drivers/media/platform/rockchip-vpu/rockchip_vpu_hw.h#117
Best regards,
Tomasz
>
> Thanks,
> baruch
>
> [1] https://chromium.googlesource.com/chromiumos/overlays/chromiumos-overlay/+/master/media-libs/libv4l/
>
> --
> http://baruch.siach.name/blog/ ~. .~ Tk Open Systems
> =}------------------------------------------------ooO--U--Ooo------------{=
> - baruch at tkos.co.il - tel: +972.52.368.4656, http://www.tkos.co.il -
