[RFC PATCH v2 00/13] Enable raw streams with software ISP

[Laurent Pinchart]

I've pushed patches 01/13, 11/13 and 12/13 already.

On Sun, Jan 26, 2025 at 11:58:17PM +0200, Laurent Pinchart wrote:
> On Fri, Jan 24, 2025 at 10:57:51PM +0100, Milan Zamazal wrote:
> > This makes raw streams working again in ‘simple’ pipeline when software
> > ISP is enabled for the given device.  At most one raw stream and one
> > processed stream (possibly both at once) are supported.
> > 
> > An example ‘cam’ invocation requesting a raw stream rather than a debayered stream:
> > 
> >   cam -c1 -C8 -s role=raw,width=1920,height=1080 -Ffile#.raw
> > 
> > Or for both raw and processed streams:
> > 
> >   cam -c1 -C8 -s role=raw,width=1920,height=1080,pixelformat=SRGGB8 -s role=viewfinder,width=1920,height=1080,pixelformat=RGB888 -Ffile#
> > 
> > When only a raw stream is requested, there are no exposure/gain
> > adjustments applied.  This could be improved in future, once software
> > ISP gets a mechanism to gather image statistics without processing and
> > using them to make the adjustments, or once manual exposure controls are
> > added to software ISP.  In the meantime, exposure must be changed
> > externally.
> 
> This is fine.
> 
> > A part of the patches is a small change to ‘cam’ PPM file handling, to
> > be able to produce PPM files together with raw files when both processed
> > and raw streams are requested.
> > 
> > The patches are RFC because I’m not sure whether they are implemented
> > properly.  It’s also necessary to determine the right balance between
> > the requested functionality (single raw + processed streams should be
> > enough for current needs), cleanness of the implementation and the
> > complexity of the patches.
> 
> The famous yak shaving balance.
> 
> As you'll see in the review of individual patches, I think there's some
> cleanup to be done. The good news is that we don't need a full yak
> shaving, just trimming some edges :-)
> 
> > Changes in v2:
> > - Completely reworked.
> > - Extended to be able to produce a raw stream together with a processed
> >   stream.
> > 
> > Milan Zamazal (13):
> >   libcamera: software_isp: Move a non-loop condition out of the loop
> >   libcamera: simple: Increase the default number of streams to 2
> >   libcamera: simple: Don't use raw output formats with conversions
> >   libcamera: simple: Add plain output configurations to software ISP
> >   libcamera: simple: Identify requested stream roles
> >   libcamera: simple: Protect against null maxPipeConfig
> >   libcamera: simple: Consider raw output configurations
> >   libcamera: simple: Handle adjusted and raw configurations separately
> >   libcamera: simple: Don't use conversion with an added raw stream
> >   libcamera: simple: Make raw streams working
> >   apps: ppm_writer: Add a missing include
> >   apps: ppm_writer: Return EIO on I/O errors
> >   apps: cam: Write raw file if PPM cannot be written
> > 
> >  src/apps/cam/file_sink.cpp                  |  16 +-
> >  src/apps/common/ppm_writer.cpp              |   7 +-
> >  src/libcamera/pipeline/simple/simple.cpp    | 188 ++++++++++++++++----
> >  src/libcamera/software_isp/software_isp.cpp |   7 +-
> >  4 files changed, 168 insertions(+), 50 deletions(-)

-- 
Regards,

Laurent Pinchart