Sorry if these questions seem trivial, but I'm a little confused by
this. The tvp5146 is just the decoder and is MUX'd into the VPFE with
the imager interface correct? So would the code to select which is sent
to the VPFE be in the tvp5146.c driver? There is a comment in the
davinci_vpfe.c file that says code needs to be added to switch between
the tvp5146 and the mt9t001 which I'm assuming is the Micron sensor and
that it would be connected to the imager interface, connectors J30 and
J31 on the dm355 DVEVM. Because of that comment I'm guessing it's not in
the davinci_vpfe.c file. Do I have to write it myself then? I guess my
question is do I need to modify the tvp5146.c code if not using the
tvp5146 and instead using the imager interface?
Stephen Berry wrote:
BT656 is what you want (and I believe it is the exact same thing as
CCIR656).
For the EVM you will need to switch the mux if you are using the
connector - I'm not sure but I think there is code in the tvp5146
driver to do this, you would just need to switch it the other way.
Based on what you have told me - I think you can get away with
changing the tvp5146.c driver to suit your sensor. You'll need to
compare the setup of the decoder to what needs to get done with the
sensor. Personally I'd start by copying the tvp5146.c file and
creating a new driver.
There is some code already written for the 7620, in
linux/drivers/media/video/ovcamchip/ov7x20.c. The problem with this
code is that it is written for v4l1 and it's not integrated into the
VPFE. But you can use it to figure out register settings....
Yes there are functions for the I2C bus in the tvp driver. No, there
isn't any documentation other than the code.
It looks like your 7620 also has auto exposure and white balance
modes... thats good news. Otherwise your application would need to do it.
Steve
Anthony Gutierrez wrote:
The camera module I have can uses an Omnivision OV7620:
http://www.electronics123.com/s.nl/it.A/id.42/.f
It has a resolution of 640x480 and can output the CCIR 601/656
standard, which is just the former name of and should be the same as
BT 601/656 correct? Assuming my camera output is pretty close to the
decoder output will I just need to select the imager interface as the
input into the VPFE instead of the tvp5146 decoder and configure my
camera via I2C? How can I do this? Are there functions for using the
I2C bus already? I'm having trouble following the davinci_vpfe.c,
tvp5146.c, ccdc_dm355.c etc. driver files and there seems to be no
documentation on these.
Stephen Berry wrote:
If your sensor is generating BT656 (that is YCbCr with embedded
sync's, horizontal and vertical blanking etc) in D1 format, then you
might not have to do too much. The default input to the 355 is from
the NTSC decoder which uses BT656.
If the sensor output is not identical to the output of an NTSC
decoder, then you will need to modify the ccdc so that you can
capture your frames correctly. If your sync signals are external you
will need to enable the inputs to the VPFE. It is likely that you
may need to modify dm355_vpfe.c and tvp5146.c as well if the sensor
raw output is a different resolution or the sensor itself needs to
be setup differently.
If your sensor does not have an automatic AWB/AE mode, then you will
need to write an application level control loop to manage this.
If you haven't guessed - this can be a big job if your sensor isn't
a direct substitute for a decoder.
Steve
Anthony Gutierrez wrote:
I want to use a CMOS imager outputting 8bit YCbCr 4:2:2 with the
dm355 EVM. What do I need to modify within the davinci_VPFE.c and
ccdc_dm355.c driver files to do something like this? And are there
any other files I need to modify? Is there any guide or
documentation for using these drivers?
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There is some code already written for the 7620,
Anthony Gutierrez wrote:
The camera module I have can uses an Omnivision OV7620:
http://www.electronics123.com/s.nl/it.A/id.42/.f
It has a resolution of 640x480 and can output the CCIR 601/656
standard, which is just the former name of and should be the same as
BT 601/656 correct? Assuming my camera output is pretty close to the
decoder output will I just need to select the imager interface as the
input into the VPFE instead of the tvp5146 decoder and configure my
camera via I2C? How can I do this? Are there functions for using the
I2C bus already? I'm having trouble following the davinci_vpfe.c,
tvp5146.c, ccdc_dm355.c etc. driver files and there seems to be no
documentation on these.
Stephen Berry wrote:
If your sensor is generating BT656 (that is YCbCr with embedded
sync's, horizontal and vertical blanking etc) in D1 format, then you
might not have to do too much. The default input to the 355 is from
the NTSC decoder which uses BT656.
If the sensor output is not identical to the output of an NTSC
decoder, then you will need to modify the ccdc so that you can
capture your frames correctly. If your sync signals are external you
will need to enable the inputs to the VPFE. It is likely that you
may need to modify dm355_vpfe.c and tvp5146.c as well if the sensor
raw output is a different resolution or the sensor itself needs to
be setup differently.
If your sensor does not have an automatic AWB/AE mode, then you will
need to write an application level control loop to manage this.
If you haven't guessed - this can be a big job if your sensor isn't
a direct substitute for a decoder.
Steve
Anthony Gutierrez wrote:
I want to use a CMOS imager outputting 8bit YCbCr 4:2:2 with the
dm355 EVM. What do I need to modify within the davinci_VPFE.c and
ccdc_dm355.c driver files to do something like this? And are there
any other files I need to modify? Is there any guide or
documentation for using these drivers?
_______________________________________________
Davinci-linux-open-source mailing list
[email protected]
http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
_______________________________________________
Davinci-linux-open-source mailing list
[email protected]
http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
