[libcamera-devel] [RFC PATCH 0/2] andriod: Basic NV12 thumbnailer

[Umang Jain]

Still RFC as couple of \todos still pending to get address; partly which
I need help with in order to know what should be the forward path from
here on.

One of the hurdle after writing the thumbnailer component was to use the
existing encoder to compress it. The encoder uses FrameBuffer parameter
to encode as of now. The result of thumbnailer is raw bytes, so either
we need to get a FrameBuffer/MappedFrameBuffer instance created out of
those raw bytes(which seems difficult) OR make the encoder flexible
enough so that we can encode directly from bytes. Patch 1/2 implements
the latter (discussed with Kieran last week).

Coming to patch 2/2, is the thumbnailer which is generated and
compressed in the PostProcessorJpeg layer. How would we embed this
in the Exif data, is still the missing piece of the puzzle. I am still
unsure where I should (thumnail + compress) in PostProcessor layer
or the Encoder layer. Both these places has it's own set of challenges
according to me. Please refer to the \todo and see if you can help me
with any ideas.

(The actual thumbnailer(.cpp / .h) has been reviewed before and I might
have not addressed all the comments from it. Although there a few
changes in there, I will make sure that the reviews are addressed when
I'll submit a non-RFC version).

Thanks!

Umang Jain (2):
  android: jpeg: encoder_libjpeg Allow encoding raw frame bytes
  android: jpeg: Add a basic NV12 image thumbnailer

 src/android/jpeg/encoder_libjpeg.cpp     |  37 +++++----
 src/android/jpeg/encoder_libjpeg.h       |   7 +-
 src/android/jpeg/post_processor_jpeg.cpp |  39 +++++++++
 src/android/jpeg/post_processor_jpeg.h   |   3 +
 src/android/jpeg/thumbnailer.cpp         | 100 +++++++++++++++++++++++
 src/android/jpeg/thumbnailer.h           |  40 +++++++++
 src/android/meson.build                  |   1 +
 7 files changed, 211 insertions(+), 16 deletions(-)
 create mode 100644 src/android/jpeg/thumbnailer.cpp
 create mode 100644 src/android/jpeg/thumbnailer.h

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2.26.2