libcamera: software_isp: Convert TODO list to markdown

To prepare for merging the two software ISP TODO lists (TODO and
gpuisp-todo.txt), convert the TODO file to markdown.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Reviewed-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com>

src/libcamera/software_isp/TODO.md

@@ -1,5 +1,16 @@
-2. Reconsider stats sharing
+# Software ISP TODO list
 
+This file contains the TODO list for the software ISP.
+
+## Common code and CPU-based implementation
+
+The TODO items in this section gather comments from patch review that were not
+deemed to require being addressed right away. The text in block quotes is
+copied directly from e-mail review.
+
+### Reconsider stats sharing
+
+```
 >>> +void SwStatsCpu::finishFrame(void)
 >>> +{
 >>> +	*sharedStats_ = stats_;
@@ -22,11 +33,11 @@
 
 That would match how we deal with hardware ISPs, and I think that's a
 good idea. It will help decoupling the processing side from the IPA.
+```
 
----
-
-3. Remove statsReady signal
+### Remove statsReady signal
 
+```
 > class SwStatsCpu
 > {
 > 	/**
@@ -50,11 +61,11 @@ Removing the signal and refactoring those classes doesn't have to be
 addressed now, I think it would be part of a larger refactoring
 (possibly also considering platforms that have no ISP but can produce
 stats in hardware, such as the i.MX7), but please keep it on your radar.
+```
 
----
-
-5. Store ISP parameters in per-frame buffers
+### Store ISP parameters in per-frame buffers
 
+```
 > /**
 >  * \fn void Debayer::process(FrameBuffer *input, FrameBuffer *output, DebayerParams params)
 >  * \brief Process the bayer data into the requested format.
@@ -68,11 +79,11 @@ stats in hardware, such as the i.MX7), but please keep it on your radar.
 
 Possibly something to address later, by storing ISP parameters in
 per-frame buffers like we do for hardware ISPs.
+```
 
----
-
-8. DebayerCpu cleanups
+### DebayerCpu cleanups
 
+```
 > >> class DebayerCpu : public Debayer, public Object
 > >>   const SharedFD &getStatsFD() { return stats_->getStatsFD(); }
 > >
@@ -105,21 +116,21 @@ the need for performances and the need for a maintainable architecture.
 > I think this falls under the lets wait until we have a GPU
 > based SoftISP MVP/POC and then do some refactoring to see which
 > bits should go where.
+```
 
----
-
-8. Decouple pipeline and IPA naming
+### Decouple pipeline and IPA naming
 
+```
 > The current src/ipa/meson.build assumes the IPA name to match the
 > pipeline name. For this reason "-Dipas=simple" is used for the
 > Soft IPA module.
 
 This should be addressed.
+```
 
----
-
-9. Doxyfile cleanup
+### Doxyfile cleanup
 
+```
 >> diff --git a/Documentation/Doxyfile.in b/Documentation/Doxyfile.in
 >> index a86ea6c1..2be8d47b 100644
 >> --- a/Documentation/Doxyfile.in
@@ -160,13 +171,14 @@ Yes, because, well... all the other IPAs were doing that...
 
 > It doesn't have to be done before merging, but could you
 > address this sooner than later ?
+```
 
----
-
-13. Improve black level and colour gains application
+### Improve black level and colour gains application
 
+```
 I think the black level should eventually be moved before debayering, and
 ideally the colour gains as well. I understand the need for optimizations to
 lower the CPU consumption, but at the same time I don't feel comfortable
 building up on top of an implementation that may work a bit more by chance than
 by correctness, as that's not very maintainable.
+```