Re: [PATCH v2] tinyjpeg: Dynamic luminance quantization table for Pixart JPEG

[Hans de Goede <hdegoede@redhat.com>]

Hi,

On 04/25/2012 06:09 PM, Jean-Francois Moine wrote:
> Hi Hans,

<snip>

> BTW, I don't think the exposure and gain controls use the right
> registers as they are coded in the actual gspca  pac7302 subdriver.
> The ms-windows driver uses the registers (3-80 / 3-03), (3-05 / 3-04),

3-03, 3-04 and 3-05 are already known and they all influence framerate /
exposure in some way. I've also ran some tests with 3-80, again it
influences framerate in some way (*). We already have a well tested and
working, fine-grained way to control exposure so I think it is best
to leave things as is exposure wise.

> (3-12)

3-12 is interesting, it is a new gain control. The pull request I've just
send (with you in the CC) contains a patch to improve gain control using
both 3-10 and 3-12 together.

> and (1-80)

1-80 is compression balance, since our decompression code for higher
compression settings (markers > 68) still is not perfect this is best
left untouched.

*) Note I've documented all registers I've ran tests with as part of
the patchset for which I've just send a pull request.

Regards,

Hans