Testing Video Input of Hawkboard - Revision history

Droy: added dsp-code at the arm+dsp function-call

2010-09-23T14:53:06Z

added dsp-code at the arm+dsp function-call

Alokprasad: wikifying the article

2010-05-21T04:09:25Z

wikifying the article

Alokprasad at 02:04, 12 May 2010

2010-05-12T02:04:15Z

Caglar: Created page with '== Problem Description == OMAP L-138 kernels are supporting composite(camera) interface of Hawkboard out of the box, however there are 3 obstacles for using it: * L-138 VPIF vi…'

2010-05-11T20:02:49Z

Created page with '== Problem Description == OMAP L-138 kernels are supporting composite(camera) interface of Hawkboard out of the box, however there are 3 obstacles for using it: * L-138 VPIF vi…'

New page

== Problem Description ==

OMAP L-138 kernels are supporting composite(camera) interface of Hawkboard out of the box, however there are 3 obstacles for using it:

* L-138 VPIF video input offers camera data in 2 plane YUV format, namely NV16.
* L-138 LCDC output, VGA output of Hawkboard, accepts display data in RGB565 format
* L-138 does not have hardware support for converting NV16 <-> RGB565

Due to these problems, if we want to see camera input on the VGA output of the board we need to perform color conversion in the software.

== Using Off-the-shelf Software Components ==

I tried GStreamer and Mplayer on the board and both were failed to capture camera input.

===GStreamer===

At the time of this writing, GStreamer v4l2 plugin, v4l2src, doesn't support NV16 format. Here is the output from 'gst-inspect v4l2src | grep NV' :

format: NV12
format: NV21

NV16 uses 4:2:2 sampling whereas NV12 uses 4:2:0.

===MPlayer===

I'm fairly sure that MPlayer should support NV16 but I couldn't make it work on my Hawkboard. MPlayer was unable to find a suitable color format for my camera. Due to performance limitations, I didn't try so hard to make it work.

== Firing up a Custom Solution ==

Since I couldn't test my camera with off-the-shelf components, I tried to do my own. Then I came-up with to solutions.

=== ARM only Solution ===

I wrote a simple V4L2 application, cross-compiled it and tried on my board. Results were:

* Camera interface was functional.
* Frame-rate was very low, maybe 3-4 fps.

=== ARM + DSP Solution ===

To increase the fps, I modified existing Codec Engine following examples:

* video_copy application : This is the ARM side application capturing camera data and showing on the VGA display.
* viddec_copy codec : This is the DSP codec doing the actual NV16 <-> RGB565 conversion.

This ARM + DSP solution gave me a 25 fps nice camera test on my board. You can find my binaries and source codes at [http://code.google.com/p/hawkboard/downloads/detail?name=vpif_example.tar.gz&can=2&q=]

=== Using Provided Binaries ===

Assumptions:

* You have a working file-system image. If you download from http://www.angstrom-distribution.org/narcissus/, you will be able to run DSP part as well.
* You have your composite camera plugged.

When you download the provided vpi_example.tar.gz from the Hawkboard download page at code.google.com and extract it you will see the following files:

* binaries
** arm+dsp
***all.x674
***app_remote.xv5T
** arm+only
***camera-test
* sources
** arm+dsp
***camera.patch
** arm+only
***.
***.
***.
* uImage

Note : I was having a TVP5146 issue with my board, such that TVP5146 was not detecting my camera and throwing input setting errors.
To overcome this situation I had to patch my kernel with the following patch. I uploaded my patched kernel for your convenience. Note that
patch can be broken due to wiki formatting, if that is the case you can find the original patch at [http://groups.google.com/group/hawkboard/browse_thread/thread/723b11a40c287a4/e2948904ae45f154?lnk=gst]

--- kernel_source_original/drivers/media/video/tvp514x.c 2010-03-18 14:33:44.000000000 +0200
+++ kernel_source/drivers/media/video/tvp514x.c 2010-05-07 00:46:05.284494625 +0300
@@ -741,8 +741,9 @@
break;
}
- if ((current_std == STD_INVALID) || (try_count < 0))
- return -EINVAL;
+ if ((current_std == STD_INVALID) || (try_count < 0)) {
+ current_std = STD_PAL_BDGHIN;
+ }
decoder->current_std = current_std;
decoder->input = input;

=== Testing ARM only Code ===

Copy ''camera-test'' ARM-only binary somewhere in your filesystem on the board and run like any application:

./camera-test

No parameters are needed, program will open ''/dev/video0'' and ''/dev/fb0'' nodes, perform color conversion and you should see the results. You can find related source code in ''sources/arm-only' directory of the archive.

=== Testing ARM-DSP Code ===

First of all make sure that your CMEM and DSPLINK modules are loaded. If you are using an Angstrom file-system, make sure that your kernel is booted with ''mem=34M'' option so that CMEM module is automatically loaded. Also you can decrease necessary kernel buffer size with ''vpif_capture.ch0_bufsize=1658880'' parameters. Here is how boot my board under U-Boot:

setenv bootargs 'console=ttyS2,115200n8 ubi.mtd=filesystem root=ubi0:hawkboard-rootfs rootfstype=ubifs mem=34M vpif_capture.ch0_bufsize=1658880'

If you need to load DSP modules by hand here is the necessary commands:

$insmod cmemk.ko phys_start=0xC2200000 phys_end=0xC3200000 pools=1x5250000,3x1048576,3x829440,1x256000,4x131072
$insmod dsplinkk.ko

Don't ask me why I didn't upload my modules as well, I don't know either :)

Then copy both ''all.x674'' and ''app_remote.xv5T'' binaries to the same folder and run the application with following commands:

./app_remote.xv5T

Now you should see 25 fps video on your screen. Unfortunately, If you want to compile this example on your own, you will need whole Codec Engine tree. You will find a patch containing necessary changes in the ''sources/arm+dsp'' folder along with my own Makefile. If you are not using DVSDK and you have a working OpenEmbedded tree around you can use provided Makefile to compile this example.

← Older revision		Revision as of 02:04, 12 May 2010
Line 1:		Line 1:
		+	[[Category: Linux]]
		+	[[Category: OMAP]]
		+	[[Category: DSP]]
		+	[[Category: Hawkboard]]
	== Problem Description ==		== Problem Description ==

@@ Line 111: / Line 111: @@
 Then copy both ''all.x674'' and ''app_remote.xv5T'' binaries to the same folder and run the application with following commands:
-  ./app_remote.xv5T
+  ./app_remote.xv5T all.x674
 Now you should see 25 fps video on your screen. Unfortunately, If you want to compile this example on your own, you will need whole Codec Engine tree. You will find a patch containing necessary changes in the ''sources/arm+dsp'' folder along with my own Makefile. If you are not using DVSDK and you have a working OpenEmbedded tree around you can use provided Makefile to compile this example.

@@ Line 15: / Line 15: @@
 == Using Off-the-shelf Software Components ==
-I tried GStreamer and Mplayer on the board and both were failed to capture camera input.
+Currently GStreamer and Mplayer on the board and both were failed to capture camera input.
 ===GStreamer===
@@ Line 28: / Line 28: @@
 ===MPlayer===
-I'm fairly sure that MPlayer should support NV16 but I couldn't make it work on my Hawkboard. MPlayer was unable to find a suitable color format for my camera. Due to performance limitations, I didn't try so hard to make it work.
+MPlayer should support NV16 but right now doesnt work on Hawkboard. MPlayer was unable to find a suitable color format for camera.
-== Firing up a Custom Solution ==
+== Custom Solution ==
-Since I couldn't test my camera with off-the-shelf components, I tried to do my own. Then I came-up with to solutions.
+Since testing of camera with off-the-shelf components couldnt be performed,following solution could be used.
 === ARM only Solution ===
-I wrote a simple V4L2 application, cross-compiled it and tried on my board. Results were:
+Make a V4L2 application, cross-compiled it and tried on the board. Results were:
 * Camera interface was functional.
@@ Line 43: / Line 43: @@
 === ARM + DSP Solution ===
-To increase the fps, I modified existing Codec Engine following examples:
+To increase the fps, modify the existing Codec Engine following examples:
 * video_copy application : This is the ARM side application capturing camera data and showing on the VGA display.
 * viddec_copy codec : This is the DSP codec doing the actual NV16 <-> RGB565 conversion.
-This ARM + DSP solution gave me a 25 fps nice camera test on my board. You can find my binaries and source codes at [http://code.google.com/p/hawkboard/downloads/detail?name=vpif_example.tar.gz&can=2&q=]
+This ARM + DSP solution that gives  a 25 fps nice camera test on the hawkboard. You can find the binaries and source codes at [http://code.google.com/p/hawkboard/downloads/detail?name=vpif_example.tar.gz&can=2&q=]
 === Using Provided Binaries ===
@@ Line 74: / Line 74: @@
 * uImage
-  Note : I was having a TVP5146 issue with my board, such that TVP5146 was not detecting my camera and throwing input setting errors.
+  Note : There might be a TVP5146 issue with hawkboard, such that TVP5146 being not detected by camera and throwing input setting errors.
-         To overcome this situation I had to patch my kernel with the following patch. I uploaded my patched kernel for your convenience. Note that
+         To overcome this situation you could patch the kernel with the following patch. Patch can be downloaded from [http://groups.google.com/group/hawkboard/browse_thread/thread/723b11a40c287a4/e2948904ae45f154?lnk=gst]
-        patch can be broken due to wiki formatting, if that is the case you can find the original patch at [http://groups.google.com/group/hawkboard/browse_thread/thread/723b11a40c287a4/e2948904ae45f154?lnk=gst]
   --- kernel_source_original/drivers/media/video/tvp514x.c        2010-03-18 14:33:44.000000000 +0200
@@ Line 101: / Line 100: @@
 === Testing ARM-DSP Code ===
-First of all make sure that your CMEM and DSPLINK modules are loaded. If you are using an Angstrom file-system, make sure that your kernel is booted with ''mem=34M'' option so that CMEM module is automatically loaded. Also you can decrease necessary kernel buffer size with ''vpif_capture.ch0_bufsize=1658880'' parameters. Here is how boot my board under U-Boot:
+First of all make sure that your CMEM and DSPLINK modules are loaded. If you are using an Angstrom file-system, make sure that your kernel is booted with ''mem=34M'' option so that CMEM module is automatically loaded. Also you can decrease necessary kernel buffer size with ''vpif_capture.ch0_bufsize=1658880'' parameters. under U-Boot:
   setenv bootargs 'console=ttyS2,115200n8 ubi.mtd=filesystem root=ubi0:hawkboard-rootfs rootfstype=ubifs mem=34M vpif_capture.ch0_bufsize=1658880'
@@ Line 109: / Line 108: @@
   $insmod cmemk.ko phys_start=0xC2200000 phys_end=0xC3200000 pools=1x5250000,3x1048576,3x829440,1x256000,4x131072
   $insmod dsplinkk.ko
 Then copy both ''all.x674'' and ''app_remote.xv5T'' binaries to the same folder and run the application with following commands: