Re: [PATCH v3 1/1] V4L2: platform: Renesas R-Car JPEG codec driver

[Mikhail Ulianov <mikhail.ulyanov@cogentembedded.com>]

On Mon, 04 May 2015 02:32:05 +0300
Laurent Pinchart <laurent.pinchart@ideasonboard.com> wrote:

> Hi Mikhail,
> 
> Thank you for the patch. Please see below for a (partial) review.
> 
> On Thursday 30 April 2015 00:53:29 Mikhail Ulyanov wrote:
> > Here's the the driver for the Renesas R-Car JPEG processing unit
> > driver.
> > 
> > The driver is implemented within the V4L2 framework as a mem-to-mem
> > device. It presents two video nodes to userspace, one for the
> > encoding part, and one for the decoding part.
> > 
> > It was found that the only working mode for encoding is no markers
> > output, so we generate it with software. In current version of
> > driver we also use software JPEG header parsing because with
> > hardware parsing performance is lower then desired.
> 
> Just out of curiosity, what is the performance impact of hardware
> parsing ?
Looks like feature of IP core. Header parsing complete/continue
sequence make it work 1.5-2 times longer, so as i remember maximum
performance with 1Mp YUV420 JPEG decoding was ~60 FPS.