Re: [PATCH RFC v2 0/3] Add Amlogic stateless H.264 video decoder for S4

[Zhentao Guo]

在 2025/11/25 18:55, Ferass El Hafidi 写道:
> [ EXTERNAL EMAIL ]
>
> Hello, quick drive-by comments:
>
> On Mon, 24 Nov 2025 03:32, Zhentao Guo via B4 Relay 
> <devnull+zhentao.guo.amlogic.com@xxxxxxxxxx> wrote:
> > Introduce initial driver support for Amlogic's new video acceleration
> > hardware architecture, designed for video stream decoding.
> >
> > Compared to the current Amlogic video decoder hardware architecture,
> > this new implementation eliminates the Esparser hardware component,
> > enabling direct vb2 buffer input. The driver is designed to support
> > the V4L2 M2M stateless decoder API. The initial phase includes support
> > for H.264 decoding on Amlogic S805X2 platform.
> >
> > The driver is capable of:
> > - Supporting stateless H.264 decoding up to a resolution 1920x1088(on 
> > the S805X2 platform).
>
> nit: 1920x1080?
The hardware requires the height to be aligned to 16 pixels, so 1080 is 
not a multiple of 16, but 1088 is. Therefore, the hardware actually 
supports 1920x1088 for decoding, which covers 1920x1080 by padding the 
height to 1088.
> > - Supporting I/P/B frame handling.
> > - Supporting vb2 mmap and dma-buf modes.
> > - Supporting frame-based decode mode. (Note that some H.264 
> > bitstreams require
> >  DPB reordering to generate reference lists, the stateless decoder 
> > driver
> >  cannot access reordered reference lists in this mode, requiring the 
> > driver
> >  to perform reference list reordering itself)
> > - Supporting NV12/NV21 output.
> > - Supporting Annex B start codes.
>
> Best regards,
> Ferass

BRs

Zhentao