[PATCH] media: hantro: Hook up RK3399 JPEG encoder output

[Nicolas Dufresne]

Le lundi 22 novembre 2021 à 11:57 +0800, Chen-Yu Tsai a écrit :
> On Sat, Nov 20, 2021 at 12:00 AM Nicolas Dufresne <nicolas at ndufresne.ca> wrote:
> > 
> > Le vendredi 19 novembre 2021 à 15:46 +0800, Chen-Yu Tsai a écrit :
> > > The JPEG encoder found in the Hantro H1 encoder block only produces a
> > > raw entropy-encoded scan. The driver is responsible for building a JPEG
> > > compliant bitstream and placing the entropy-encoded scan in it. Right
> > > now the driver uses a bounce buffer for the hardware to output the raw
> > > scan to.
> > > 
> > > In commit e765dba11ec2 ("hantro: Move hantro_enc_buf_finish to JPEG
> > > codec_ops.done"), the code that copies the raw scan from the bounce
> > > buffer to the capture buffer was moved, but was only hooked up for the
> > > Hantro H1 (then RK3288) variant. The RK3399 variant was broken,
> > > producing a JPEG bitstream without the scan, and the capture buffer's
> > > .bytesused field unset.
> > > 
> > > Fix this by duplicating the code that is executed when the JPEG encoder
> > > finishes encoding a frame. As the encoded length is read back from
> > > hardware, and the variants having different register layouts, the
> > > code is duplicated rather than shared.
> > > 
> > > Fixes: e765dba11ec2 ("hantro: Move hantro_enc_buf_finish to JPEG codec_ops.done")
> > > Signed-off-by: Chen-Yu Tsai <wenst at chromium.org>
> > > ---
> > > This was developed on the downstream ChromeOS 5.10 kernel (with a hack
> > > for .data_offset) and tested with ChromeOS's jpeg_encode_accelerator_unittest
> > > patched to accept non-JFIF JPEG streams (https://crrev.com/c/3291480).
> > > 
> > > This was then forward-ported to mainline (name and filename changes) and
> > > compile tested only.
> > 
> > Tested with GStreamer on top of 5.16-rc1 from media_stage.git. Not perfect but
> > at least the the output it valid. Test command was:
> > 
> >   gst-launch-1.0 videotestsrc num-buffers=2 ! v4l2jpegenc ! filesink
> > location=test.jpg
> > 
> > Notice that I encode two frames, it seems like the draining flow is broken in
> > this driver. GStreamer will queue the frame and issue CMD_START immediately, the
> > driver will skip the encode, leaving me with an empty file.
> 
> The hantro driver doesn't implement ENC_CMD, which IIRC is used for the
> draining flow. I guess that's something to fix, since the mem2mem stateful
> encoder spec seems to require it. Or does that spec not apply to the JPEG
> encoders?

I'm pretty sure its required. But this isn't a regression from this patch.

> 
> > Tested-by: Nicolas Dufresne <nicolas.dufresne at collabora.com>
> 
> Thanks!
> 
> ChenYu