I have finally managed to get a video stream (at least i can say for
now) by changing the frame resolution inside the python opencv code
using instructions on
http://stackoverflow.com/questions/11420748/setting-camera-parameters-in-opencv-python.
The maximum resolution i can set it to was 640x480 with a 5fps frame
rate, increasing the frame rate will result in a select timeout message.
At 320x240 i can set it up to 30fps and running htop the CPU
utilization will be fluctuating around 86-90%. The python code was
taking about 12% and most of the chunk was on tightvnc about 60% (maybe
because of the frame window being displayed).
This is the code i was running;
import cv2
#capture from camera at location 0
cap = cv2.VideoCapture(0)
#set the width and height, and UNSUCCESSFULLY set the exposure time
cap.set(3,320)
cap.set(4,240)
cap.set(5, 30)
while True:
ret, img = cap.read()
cv2.imshow("input", img)
#cv2.imshow("thresholded", imgray*thresh2)
key = cv2.waitKey(10)
if key == 27:
break
cv2.destroyAllWindows()
cap.release()
And also the resolution i forced the camera to in the opencv code is the
one displayed after running v4l2-ctl -V;
root@beaglebone:~/Project/Testing# v4l2-ctl -V
Format Video Capture:
Width/Height : 320/240
Pixel Format : 'YUYV'
Field : None
Bytes per Line: 640
Size Image : 153600
Colorspace : SRGB
root@beaglebone:~/Project/Testing#
What you figured out about bandwidth is really a serious issue. I have a
friend who did not experience this problem on their RPi (only much
higher resolutions resulted in select timeout messages, message because
i don't think it is an error) maybe because it has many USB ports
meaning higher bandwidth compared to BBB with only one.
I wonder what will happen when connecting the BBB wirelessly, with a
wifi dongle and camera on a USB hub.
On Thu, May 26, 2016 at 8:39 AM, Tinashe Mudavanhu <[email protected]
<mailto:[email protected]>> wrote:
Silva,
It does have MJPEG but opencv is converting the format to YUYV. And
also does your board have I/O pins digital and analogue?
On Thu, May 26, 2016 at 8:35 AM, Tinashe Mudavanhu
<[email protected] <mailto:[email protected]>> wrote:
The 160x120 video stream had no latency but the other camera
with 1280x720 was slow, video was displayed as images being
flipped like book pages.
I need to understand something from your files. Does it mean the
rest of my iris recognition code has to be in the
framegrabber.py client file and also this file can also run on
BBB? Do i need the zhelper.h file when my PC is running Ubuntu?
Here is my setup like. I have a PC running Ubuntu connected to
the BBB via usb and also sharing internet via the same cable
(there is no wired connection, only the PC is connected to
wifi). I want to see the video stream on my BBB for debugging
purposes and once it is working fine it doesn't have to show the
video stream. I am accessing the BBB Desktop/GUI via a tightvnc
client running on my Ubuntu PC. Thats when i will move to the
hub for a wired connection so that everyone connected to the hub
can access web pages served by the BBB (running lighttpd
webserver).
I was successful in the part of running BBB as a webserver
(without an video stream to show on the site because i don't
need it) but then the first part of getting a video stream to
show was not possible because of select timeout errors.
On Thu, May 26, 2016 at 12:35 AM, Matthew Witherwax
<[email protected] <mailto:[email protected]>> wrote:
Looks like framegrabber was able to capture images based on
the output you provided. Did you look at the images?
If it works for you then the code for the subscriber here
http://blog.lemoneerlabs.com/post/bbb-mjpeg-streaming will
show you how to load it into opencv.
------------------------------------------------------------------------
From: João M. S. Silva <mailto:[email protected]>
Sent: 5/25/2016 4:13 PM
To: [email protected]
<mailto:[email protected]>
Subject: Re: [beagleboard] Re: VGA camera capture
If the camera has a good compression mechanism (e.g. MJPEG),
it may be
softer on the USB bus.
In our board, we are using OpenCV but we don't capture
images with the
OpenCV instruction. Instead, we use something like this:
https://linuxtv.org/downloads/v4l-dvb-apis/v4l2grab-example.html
For video capturing there is also an example:
https://linuxtv.org/downloads/v4l-dvb-apis/capture-example.html
Note that OpenCV uses v4l underneath.
On 25/05/2016 16:51, Tinashe Mudavanhu wrote:
> Silva,
>
> There has to be way. Dereck Molloy
> https://www.youtube.com/watch?v=8QouvYMfmQo was able to
get a video
> stream then its possible to video stream with BBB. I
don't have much
> time to look for another development board because the
Project is due
> next week.
>
> On Wed, May 25, 2016 at 5:48 PM, Tinashe Mudavanhu
<[email protected] <mailto:[email protected]>
> <mailto:[email protected] <mailto:[email protected]>>>
wrote:
>
> Hi,
>
> The same is happening on the other webcam i have (not
sure if its
> openCV changing resolution). I bought it on
AliExpress and has the
> following discription; HD 1.3 megapixel 960p 2.8-12mm
varifocal lens
> Aptina AR0130 android external usb camera module with
IR cut
> ELP-USB130W01MT-FV
>
<http://www.aliexpress.com/item/HD-1-3-megapixel-2-8-12mm-varifocal-lens-android-external-usb-camera-module-with-IR/32295825258.html>.
> The supplier can be found on http://www.elpcctv.com.
>
> Since there are no errors, what could be the problem?
Is there some
> dependencies i have to install?
>
> I tested with your framebrabber.c code and was
getting this (see
> below) with the Logitech webcam,
>
> root@beaglebone:~# time ./framegrabber -f mjpeg -H
480 -W 640 -c
> 1000 -I 30
> Startup took 0.010000 seconds
> Captured 1000 frames in 0.220000 seconds
> Shutdown took 0.000000 seconds
>
>
> real 0m42.068s
> user 0m0.025s
> sys 0m0.223s
>
> The no name webcam was giving the following results;
> root@beaglebone:~# time ./framegrabber -f mjpeg -H
480 -W 640 -c
> 1000 -I 30
> Startup took 0.020000 seconds
> Captured 1000 frames in 0.260000 seconds
> Shutdown took 0.000000 seconds
>
>
> real 2m10.965s
> user 0m0.033s
> sys 0m0.262s
> root@beaglebone:~#
>
>
>
> On Wed, May 25, 2016 at 5:23 PM, Matthew Witherwax
> <[email protected] <mailto:[email protected]>
<mailto:[email protected] <mailto:[email protected]>>> wrote:
>
> There are no actual errors in the output you posted.
>
> Do you have access to any other webcams? I have
tested this
> with the Logitech C920, the Logitech C270, and
the PS3Eye.
> Without access to your webcam, it is hard for me
to look into
> what is going on.
>
>
> On Wednesday, May 25, 2016 at 8:57:55 AM UTC-5,
Tinashe
> Mudavanhu wrote:
>
> The timeout error resurfaced again, i
followed you blog post
> on
>
http://blog.lemoneerlabs.com/3rdParty/Darling_BBB_30fps_DRAFT.html
> but got the following errors in compiling
libjpeg-turbo ;
>
> root@beaglebone:~/libjpeg-turbo-1.3.0/build# make
> make all-recursive
> make[1]: Entering directory
`/root/libjpeg-turbo-1.3.0/build'
> Making all in java
> make[2]: Entering directory
> `/root/libjpeg-turbo-1.3.0/build/java'
> make[2]: Nothing to be done for `all'.
> make[2]: Leaving directory
> `/root/libjpeg-turbo-1.3.0/build/java'
> Making all in simd
> make[2]: Entering directory
> `/root/libjpeg-turbo-1.3.0/build/simd'
> make all-am
> make[3]: Entering directory
> `/root/libjpeg-turbo-1.3.0/build/simd'
> make[3]: Nothing to be done for `all-am'.
> make[3]: Leaving directory
> `/root/libjpeg-turbo-1.3.0/build/simd'
> make[2]: Leaving directory
> `/root/libjpeg-turbo-1.3.0/build/simd'
> Making all in md5
> make[2]: Entering directory
> `/root/libjpeg-turbo-1.3.0/build/md5'
> make[2]: Nothing to be done for `all'.
> make[2]: Leaving directory
`/root/libjpeg-turbo-1.3.0/build/md5'
> make[2]: Entering directory
`/root/libjpeg-turbo-1.3.0/build'
> make[2]: Leaving directory
`/root/libjpeg-turbo-1.3.0/build'
> make[1]: Leaving directory
`/root/libjpeg-turbo-1.3.0/build'
> root@beaglebone:~/libjpeg-turbo-1.3.0/build#
>
>
> Before compiling libjpeg-turbo i tested my
code to see what
> will be happening on the resolution and frame
rate. I am
> working with a Logitech QuickCam E3500 which
has support for
> both YUVY and MJPEG. I set the resolution to
320x240 with a
> 30fps frame rate but after running the code,
got select
> timeout errors and the resolution had changed
to 640x480
> YUVY with a 15fps frame rate;
>
> root@beaglebone:~/libjpeg-turbo-1.3.0/build#
v4l2-ctl -V
> Format Video Capture:
> Width/Height : 640/480
> Pixel Format : 'YUYV'
> Field : None
> Bytes per Line: 1280
> Size Image : 614400
> Colorspace : SRGB
> root@beaglebone:~/libjpeg-turbo-1.3.0/build#
>
>
>
>
> On Tue, May 24, 2016 at 1:22 AM, Tinashe
Mudavanhu
> <[email protected]
<mailto:[email protected]>> wrote:
>
> Hi Matthew,
>
> I'm a rookie in this linux/opencv area i
wouldn't really
> know what it means, only learning from
you. I posted a
> question
>
https://groups.google.com/forum/#!category-topic/beagleboard/debian/VFuvveM_8Gc
> looking for a solution because it always
happened when i
> plugged in the webcam on BBB. Running the
command i
> previously mentioned ended my woes.
>
> On Tue, May 24, 2016 at 1:04 AM, Matthew
Witherwax
> <[email protected]
<mailto:[email protected]>> wrote:
>
> The issue causing the select time out
detailed in my
> article has to do with how much data
is being sent
> over the USB and how it is sent.
Reducing the frame
> rate reduces the load on the USB.
Looking at the
> articles you linked, one says it
solved an issue but
> not the select timeout, and the other
shows an error
> message that says it could not
allocate memory.
> Neither one of these are the cause of
the select
> timeout I addressed.
>
> The select timeout occurs when the
select times out.
> Looks like in the cases in your links
a previous
> call to allocate memory failed
followed by select
> failing. I have never had an issue
with memory
> allocation. All my troubles had to do
with too much
> data on the USB. You might want to
confirm what your
> actual problem is.
>
------------------------------------------------------------------------
> From: Tinashe Mudavanhu
> Sent: 5/23/2016 4:58 PM
> To: [email protected]
<mailto:[email protected]>
> Subject: Re: [beagleboard] Re: VGA
camera capture
>
> Hi Matthew,
>
> I looked into the article as i went
through your
> discussion but did not try the
framegrabber.c, will
> test it though. I finally got a
solution to the
> problem from links listed below. It
kind of made
> sense to me (lack of memory in ARM
systems) because
> running the same code on my PC worked
perfectly
> well. Running this command `sysctl
> vm.overcommit_memory=1` worked for me
after a long
> struggle. What i'm not really sure
are the
> implications (being it on Hardware or
Software) if
> there comes a state when large size
memory is really
> needed.
>
>
> [1]:
> https://www.raspberrypi.org/forums/viewtopic.php?f=31&t=17773
> [2]:
>
https://tequals0.wordpress.com/2014/03/24/libv4l2-error-allocation-conversion-buffer-using-opencv-on-a-pi/
>
> On Mon, May 23, 2016 at 10:25 PM,
Matthew Witherwax
> <[email protected]
<mailto:[email protected]>> wrote:
>
> Hi Tinashe,
>
> Please see my article here
> http://blog.lemoneerlabs.com/post/BBB-webcams
> There is a version of
framegrabber.c linked to
> it that allows you to specify the
frame rate
> with the command line parameter
-I. If reducing
> the frame rate works for you,
then the code for
> framegrabber should provide a
starting point for
> accomplishing the same thing in
your own program.
>
> On Mon, May 23, 2016 at 2:43 PM,
Tinashe
> Mudavanhu <[email protected]
<mailto:[email protected]>> wrote:
>
> Firstly i would like to say i
came across
> your discussion looking for
select timeout
> error solution but as i went
through it i
> didnt notice if you found a
solution, but if
> you have it now, i would
appreciate it. The
> select timeout error still
seems to be in
> existence even on BBB Rev C
with kernel
> 3.8.13-bone79. I am working
on an Iris
> recognition system that
initially has to
> track eyes in a live video
stream (from
> there captures cropped eye
images that will
> be processed). I have
installed different
> OpenCV versions, 2.4.9,
2.4.11 and 3.0.0 and
> in all of them i am getting
the same error.
> I am working with a Logitech,
Inc. QuickCam
> E 3500 webcam. I am accessing
the BBB
> Desktop using Tightvnc client
on my PC
> running Ubuntu 14.04 LTS.
>
> What is surprising is that it
is capable of
> video streaming with opencv
installed by
> apt-get (apt-get install
python-opencv) but
> the limitation with this
version is that it
> has very old cv bindings and
documentation
> on some functions for
Histogram equalisation
> is not available online. I am
stuck, i need
> your help.
>
> On Tuesday, 10 September 2013
16:50:46
> UTC+2, Matthew Witherwax wrote:
>
> Getting another BBB or
raspberry pi
> probably wont help, but a
U2 from
> HardKernel here
>
http://www.hardkernel.com/renewal_2011/products/prdt_info.php?g_code=G135341370451
> probably would. You can
use the BBB to
> do all IO and use the
processing power
> of the U2 to handle
compute intensive
> tasks. That is actually
my end goal.
> The cpu use I stated
earlier was without
> showing the image.
Displaying the image
> will increase cpu use.
>
> I am also working on a
tracking
> application with the
webcam mounted on a
> servo. For my purposes,
I do not need
> to see the image on the
BBB and can push
> it over wifi to my laptop
if I want to
> view it.
>
> As far as cv code, what
are you looking
> for? I have posted a
tool on my blog
> here
> http://blog.lemoneerlabs.com/post/shades-of-red
> to help you find HSV
values from images
> to allow you to to find
values to
> threshold target colors.
I will post
> another one on using HSV
ranges to
> threshold an image to
isolate things
> like a red colored ball.
I have been
> implementing OpenCV code
using python
> right now for
experimentation, but you
> should be able to
translate it to C++ or
> your language of choice.
>
> The command v4l2-ctl
--list-formats-ext
> will tell you the pixel
formats and
> resolutions supported by
your camera.
>
> Hope this helps,
>
> Matthew Witherwax
>
>
> On Tue, Sep 10, 2013 at
8:48 AM, James
> Richins
<[email protected] <mailto:[email protected]>>
wrote:
>
> Matthew,
>
> It does remind of
something on Derek
> Molloy's site in that
he adds coding
> to deal with the h264
codec for
> taking stills with
opencv. I
> hesitated at the
idea. Interestingly
> even using an
additional bbb or
> raspberry pi might
not even help.
> I'm looking at camera
tracking
> objects/object
recognition and servo
> control.
> I might find that by
not displaying
> the video on the
monitor, that the
> tracking and servo
control can work
> less than 100% CPU.
> I have yet to
implement the cv code
> for that, it's a real
struggle to
> find good code. And
not get errors.
> I have managed servo
control through
> python and manual
entering numbers
> so its ultimately
possible.
> I'm not sure if my
camera does
> anything other than
yuyv. I'd be
> interested in
connecting an Ethernet
> cam to the Ethernet
port and read
> camera data from
there, but you'd
> probably run into the
same problem.
> Ethernet cam to pc
processing cv
> code, wifi to
beaglebone servo
> control might be
good. But its
> probably a slow
process and too
> complicated for me.
>
> Anyway good luck with
your project.
>
> James
>
> On 10 Sep 2013, at
13:57, Matthew
> Witherwax
<[email protected] <mailto:[email protected]>> wrote:
>
>> James,
>>
>> I have not done any
cpu testing
>> other than while
saving single
>> frames. In MJPEG
format,
>> capturing a single
frame at
>> 1920x1080 30 fps and
saving it was
>> taking about 6%
cpu. Doing the
>> same in YUYV at a
reduced
>> resolution and
converting to jpeg
>> was taking about
70%. I would not
>> rush out to buy a
h264 camera.
>> First, I am not sure
OpenCV
>> decodes h264
streams. Second, if
>> it did, I am not
sure you would
>> see much improvement
because of
>> the need to decode
the h264
>> stream. If the BBB
does this in
>> hardware is likely
wont be bad,
>> but if it is a software
>> implementation we
are just
>> shifting the
burden. I am
>> currently working
through several
>> tradeoffs. YUYV
should give the
>> truest image free of
compression
>> artifacts, but will
be larger and
>> require more
resources to capture
>> and process. MJPEG
may suffer
>> from compression
artifacts, but
>> images can be
captured more
>> quickly and at higher
>> resolutions. One
has to decide
>> what combination of
frame rate,
>> resolution, and
fidelity are
>> required. I am
currently working
>> through the
permutations to see
>> what suits my
application.
>>
>> An option I have
open is to send
>> the captured images
over a wifi
>> link to a computer
that runs all
>> the OpenCV code and
pipes back the
>> data I am after.
This leaves the
>> BBB mostly free to
do other work.
>> I will update as I
progress.
>>
>> Matthew Witherwax
>>
>>
>> On Tue, Sep 10, 2013
at 7:35 AM,
>> James Richins
>>
<[email protected] <mailto:[email protected]>>
wrote:
>>
>>
>>
>>
[The entire original message is not included.]
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