Skip to contentSkip to conversation

Comparisons of images between Dazzle DVC100, EasyCap stk1160 and Hauppauge ImapctVCB-e in Linux.

DISCUSSION Steve Cookson 5 participants 5 messages Apr 23, 2014 – Apr 25, 2014 1 message not in the archive Media (V4L/DVB)

lore
Share & tools
lore
#0 lore raw

Hi Guys,

I would be interested in your views of the comparisons of these images. The still is the image of a duodenum taken during an endoscopy and recorded to a DVD player (via an s-video or composite cable). Although the endoscope is an HD endoscope, the DVD recorder isn't and the resulting video is 720x480i59.94.

Here are further details of the video:-

Format : MPEG Video v2
Format profile : Main@Main
Format settings, BVOP : Yes, Matrix : Custom, GOP : M=3, N=15 Bit rate mode : Variable
Bit rate : 4 566 Kbps
Maximum bit rate : 10 000 Kbps
Width : 720 pixels
Height : 480 pixels
Display aspect ratio : 4:3
Frame rate : 29.970 fps
Standard : NTSC
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Interlaced
Scan order : Top Field First
Compression mode : Lossy
Bits/(Pixel*Frame) : 0.441

The video was played through Dragon Player and the video signal has exited through a mini-VGA port defined as 640x480 and passed through a VGA->S-Video converter to an s-video cable.

The cable has in turn been connected in turn to a Dazzle DVC100, an EasyCap stk1160 and a Hauppauge ImapctVCB-e.

Each setting (eg brightness and contrast etc) has as near as possible to mid-range and a screengrab taken.

The results are shown here:

Original: http://tinypic.com/usermedia.php?uo=fNkd6hpTbcMrgmD6gSf74Ih4l5k2TGxc

Dazzle DVC100: http://tinypic.com/usermedia.php?uo=fNkd6hpTbcMaOf4QTsIefYh4l5k2TGxc

ImpactVCB-e: http://tinypic.com/usermedia.php?uo=fNkd6hpTbcM7i72IqGujuIh4l5k2TGxc

STK1160: http://tinypic.com/usermedia.php?uo=fNkd6hpTbcPO7kmQk/IS94h4l5k2TGxc

I would be grateful for your views on the quality of the images.

Is one of materially higher quality than the others, or can I adjust the settings to improve the quality of one of them more.

It seems to me that the Hauppauge is marginally better than the others. What do you think?

Can I improve the test?

Regards

Steve.

#1 lore raw

Hi Guys,

(I'm copying Ezequial on this because of the work he has done on the stk1160).

My colleague (a Doctor) had this to say on the medical images I posted earlier (see below):

Quoted 1 line

The impactVCB-e image is redder and less clear. The dvc100 and easycap seem similar to me and both of them are not as good as the original one.

So I have to ask how is it that the cheap little EasyCap is performing at the same level as the Dazzle DVC100 and better than the ImpactVCB-e?

It seems to me that the more complex and expensive DVC100 and ImpactVCB-e should perform well and that the EasyCap should be the runner up.

If the DVC100 and ImpactVCB-e had had the same love and attention that Ezequial has shown the EasyCap would they outperform it?

The ImpactVCB-e is easier to use internally and the Dazzle is external. Does the fact that the ImpactVCB-e has a PCI-e connector help it at all?

Otherwise I should just focus on EasyCap for my raw SD capture and move on.

Thanks,

Steve

Quoted 60 lines · Steve Cookson

Hi Guys,

I would be interested in your views of the comparisons of these images. The still is the image of a duodenum taken during an endoscopy and recorded to a DVD player (via an s-video or composite cable). Although the endoscope is an HD endoscope, the DVD recorder isn't and the resulting video is 720x480i59.94.

Here are further details of the video:-

Format : MPEG Video v2
Format profile : Main@Main
Format settings, BVOP : Yes, Matrix : Custom, GOP : M=3, N=15 Bit rate mode : Variable
Bit rate : 4 566 Kbps
Maximum bit rate : 10 000 Kbps
Width : 720 pixels
Height : 480 pixels
Display aspect ratio : 4:3
Frame rate : 29.970 fps
Standard : NTSC
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Interlaced
Scan order : Top Field First
Compression mode : Lossy
Bits/(Pixel*Frame) : 0.441

The video was played through Dragon Player and the video signal has exited through a mini-VGA port defined as 640x480 and passed through a VGA->S-Video converter to an s-video cable.

The cable has in turn been connected in turn to a Dazzle DVC100, an EasyCap stk1160 and a Hauppauge ImapctVCB-e.

Each setting (eg brightness and contrast etc) has as near as possible to mid-range and a screengrab taken.

The results are shown here:

Original: http://tinypic.com/usermedia.php?uo=fNkd6hpTbcMrgmD6gSf74Ih4l5k2TGxc

Dazzle DVC100: http://tinypic.com/usermedia.php?uo=fNkd6hpTbcMaOf4QTsIefYh4l5k2TGxc

ImpactVCB-e: http://tinypic.com/usermedia.php?uo=fNkd6hpTbcM7i72IqGujuIh4l5k2TGxc

STK1160: http://tinypic.com/usermedia.php?uo=fNkd6hpTbcPO7kmQk/IS94h4l5k2TGxc

I would be grateful for your views on the quality of the images.

Is one of materially higher quality than the others, or can I adjust the settings to improve the quality of one of them more.

It seems to me that the Hauppauge is marginally better than the others. What do you think?

Can I improve the test?

Regards

Steve.

Signature · 3 lines
To unsubscribe from this list: send the line "unsubscribe linux-media" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

A message that is not in the archive (sent off-list or not yet received): CALzAhNWvQ1ZYL-0rK2w7yPwzm9QyyCN8JvRyjGhq5eO6rOH9dw@mail.gmail.com

#3 lore raw

Doh, HTML cause vger to drop it. Resending.

Quoted 168 lines · Steven Toth
Quoted 3 lines · Steve Cookson

Hi Guys,

Hello again.

Quoted 4 lines

(I'm copying Ezequial on this because of the work he has done on the stk1160).

Quoted 9 lines

My colleague (a Doctor) had this to say on the medical images I posted earlier (see below):

Quoted 2 lines

The impactVCB-e image is redder and less clear. The dvc100 and easycap
seem similar to me and both of them are not as good as the original one.

So I have to ask how is it that the cheap little EasyCap is performing at the same level as the Dazzle DVC100 and better than the ImpactVCB-e?

Its usually either because the Linux engineers simply aren't focused on improving quality for the last 'mile', or that the ADC/Video digitizer differers between products. 'Redder' isn't usually a differentiation between video digitizer silicon, its miss-configuration - for example.

Quoted 4 lines

It seems to me that the more complex and expensive DVC100 and ImpactVCB-e should perform well and that the EasyCap should be the runner up.

Not necessarily, but I can understand why you may think that. The reality is
- you are measuring the work of individuals who we're not paid to create these Linux drivers. They work well enough for their needs, they scratched their own itch, then they moved on, more than likely this is the case. So, you are seeing a mixture of different silicon, different attention to detail, different default values and different levels of commitment in the driver developers.

Quoted 3 lines

If the DVC100 and ImpactVCB-e had had the same love and attention that Ezequial has shown the EasyCap would they outperform it?

Hard to say. With my experience working for Hauppauge, directly in their engineering team, having worked on literally hundreds of products, lots of different video digitizer, they're all fairly close quality wise in general, with good signals, with the right drivers.

What makes a good video digitizer stand out from a poor one, it how it performs in very poor signal conditions.

Quoted 4 lines

The ImpactVCB-e is easier to use internally and the Dazzle is external. Does the fact that the ImpactVCB-e has a PCI-e connector help it at all?

Invariably not.

Quoted 4 lines

Otherwise I should just focus on EasyCap for my raw SD capture and move on.

You need to make that judgement call. If you are building a business around medical imaging and have no engineering capability to improve drivers, go with what your gut says and what's available to you today. You shouldn't rely on the good will of Linux engineers to fix your business requirements in their spare time, in the coming weeks or months.

Or, hire a consultant to improve the drivers for you and the rest of the Linux community. This what everyone else does.

- Steve

Quoted 83 lines

Thanks,

Steve

Quoted 75 lines · Steve Cookson

Hi Guys,

I would be interested in your views of the comparisons of these images. The still is the image of a duodenum taken during an endoscopy and recorded to a DVD player (via an s-video or composite cable). Although the endoscope is an HD endoscope, the DVD recorder isn't and the resulting video is 720x480i59.94.

Here are further details of the video:-

Format : MPEG Video v2
Format profile : Main@Main
Format settings, BVOP : Yes, Matrix : Custom, GOP : M=3, N=15 Bit rate mode : Variable
Bit rate : 4 566 Kbps
Maximum bit rate : 10 000 Kbps
Width : 720 pixels
Height : 480 pixels
Display aspect ratio : 4:3
Frame rate : 29.970 fps
Standard : NTSC
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Interlaced
Scan order : Top Field First
Compression mode : Lossy
Bits/(Pixel*Frame) : 0.441

The video was played through Dragon Player and the video signal has exited through a mini-VGA port defined as 640x480 and passed through a VGA->S-Video converter to an s-video cable.

The cable has in turn been connected in turn to a Dazzle DVC100, an EasyCap stk1160 and a Hauppauge ImapctVCB-e.

Each setting (eg brightness and contrast etc) has as near as possible to mid-range and a screengrab taken.

The results are shown here:

Original:
http://tinypic.com/usermedia.php?uo=fNkd6hpTbcMrgmD6gSf74Ih4l5k2TGxc

Dazzle DVC100:
http://tinypic.com/usermedia.php?uo=fNkd6hpTbcMaOf4QTsIefYh4l5k2TGxc

ImpactVCB-e:
http://tinypic.com/usermedia.php?uo=fNkd6hpTbcM7i72IqGujuIh4l5k2TGxc

STK1160:
http://tinypic.com/usermedia.php?uo=fNkd6hpTbcPO7kmQk/IS94h4l5k2TGxc

I would be grateful for your views on the quality of the images.

Is one of materially higher quality than the others, or can I adjust the settings to improve the quality of one of them more.

It seems to me that the Hauppauge is marginally better than the others. What do you think?

Can I improve the test?

Regards

Steve.

--
To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html

--
Steven Toth - Kernel Labs
http://www.kernellabs.com

Signature · 3 lines
Steven Toth - Kernel Labs
http://www.kernellabs.com
+1.646.355.8490
#4 lore raw

I looked at the pictures as well and I noticed a few things:

The aspect ratio of the impactvcb-e isn't right, it's too narrow. What width and height did you specify when capturing? I can't test this myself as I'm abroad, but try 720x480 or 768x480.

I also noticed that the cx23885 driver selects slightly incorrect default brightness, contrast and saturation values. Whether that is the cause of the color differences is debatable, but you can try using my repo:

git://linuxtv.org/hverkuil/media_tree.git

Checkout the cx23 branch.

This branch contains a pile of cleanup patches including a conversion to the control framework, which should ensure correct (to my knowledge) defaults for the color controls.

Regards,

Hans

Quoted 174 lines · Steven Toth

Doh, HTML cause vger to drop it. Resending.

Quoted 168 lines · Steven Toth
Quoted 3 lines · Steve Cookson

Hi Guys,

Hello again.

Quoted 4 lines

(I'm copying Ezequial on this because of the work he has done on the stk1160).

Quoted 9 lines

My colleague (a Doctor) had this to say on the medical images I posted earlier (see below):

Quoted 2 lines

The impactVCB-e image is redder and less clear. The dvc100 and easycap
seem similar to me and both of them are not as good as the original one.

So I have to ask how is it that the cheap little EasyCap is performing at the same level as the Dazzle DVC100 and better than the ImpactVCB-e?

Its usually either because the Linux engineers simply aren't focused on improving quality for the last 'mile', or that the ADC/Video digitizer differers between products. 'Redder' isn't usually a differentiation between video digitizer silicon, its miss-configuration - for example.

Quoted 4 lines

It seems to me that the more complex and expensive DVC100 and ImpactVCB-e should perform well and that the EasyCap should be the runner up.

Not necessarily, but I can understand why you may think that. The reality is
- you are measuring the work of individuals who we're not paid to create these Linux drivers. They work well enough for their needs, they scratched their own itch, then they moved on, more than likely this is the case. So, you are seeing a mixture of different silicon, different attention to detail, different default values and different levels of commitment in the driver developers.

Quoted 3 lines

If the DVC100 and ImpactVCB-e had had the same love and attention that Ezequial has shown the EasyCap would they outperform it?

Hard to say. With my experience working for Hauppauge, directly in their engineering team, having worked on literally hundreds of products, lots of different video digitizer, they're all fairly close quality wise in general, with good signals, with the right drivers.

What makes a good video digitizer stand out from a poor one, it how it performs in very poor signal conditions.

Quoted 4 lines

The ImpactVCB-e is easier to use internally and the Dazzle is external. Does the fact that the ImpactVCB-e has a PCI-e connector help it at all?

Invariably not.

Quoted 4 lines

Otherwise I should just focus on EasyCap for my raw SD capture and move on.

You need to make that judgement call. If you are building a business around medical imaging and have no engineering capability to improve drivers, go with what your gut says and what's available to you today. You shouldn't rely on the good will of Linux engineers to fix your business requirements in their spare time, in the coming weeks or months.

Or, hire a consultant to improve the drivers for you and the rest of the Linux community. This what everyone else does.

- Steve

Quoted 83 lines

Thanks,

Steve

Quoted 75 lines · Steve Cookson

Hi Guys,

I would be interested in your views of the comparisons of these images. The still is the image of a duodenum taken during an endoscopy and recorded to a DVD player (via an s-video or composite cable). Although the endoscope is an HD endoscope, the DVD recorder isn't and the resulting video is 720x480i59.94.

Here are further details of the video:-

Format : MPEG Video v2
Format profile : Main@Main
Format settings, BVOP : Yes, Matrix : Custom, GOP : M=3, N=15 Bit rate mode : Variable
Bit rate : 4 566 Kbps
Maximum bit rate : 10 000 Kbps
Width : 720 pixels
Height : 480 pixels
Display aspect ratio : 4:3
Frame rate : 29.970 fps
Standard : NTSC
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Interlaced
Scan order : Top Field First
Compression mode : Lossy
Bits/(Pixel*Frame) : 0.441

The video was played through Dragon Player and the video signal has exited through a mini-VGA port defined as 640x480 and passed through a VGA->S-Video converter to an s-video cable.

The cable has in turn been connected in turn to a Dazzle DVC100, an EasyCap stk1160 and a Hauppauge ImapctVCB-e.

Each setting (eg brightness and contrast etc) has as near as possible to mid-range and a screengrab taken.

The results are shown here:

Original:
http://tinypic.com/usermedia.php?uo=fNkd6hpTbcMrgmD6gSf74Ih4l5k2TGxc

Dazzle DVC100:
http://tinypic.com/usermedia.php?uo=fNkd6hpTbcMaOf4QTsIefYh4l5k2TGxc

ImpactVCB-e:
http://tinypic.com/usermedia.php?uo=fNkd6hpTbcM7i72IqGujuIh4l5k2TGxc

STK1160:
http://tinypic.com/usermedia.php?uo=fNkd6hpTbcPO7kmQk/IS94h4l5k2TGxc

I would be grateful for your views on the quality of the images.

Is one of materially higher quality than the others, or can I adjust the settings to improve the quality of one of them more.

It seems to me that the Hauppauge is marginally better than the others. What do you think?

Can I improve the test?

Regards

Steve.

--
To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html

--
Steven Toth - Kernel Labs
http://www.kernellabs.com

#5 lore raw
In reply to Steve Cookson

On Apr 25, Steve Cookson wrote:
[..]

Quoted 4 lines

If the DVC100 and ImpactVCB-e had had the same love and attention that Ezequial has shown the EasyCap would they outperform it?

I really appreciate the kind words and I'm happy to see the driver is being used and works well.

However, to be fair, the stk1160 is just a little link in a larger chain. The video decoder is controlled through another driver (saa7115) and so I've little merit in the image quality.

[..]

Quoted 3 lines

Otherwise I should just focus on EasyCap for my raw SD capture and move on.

Hm.. hard to say. Easycap stk1160 devices are hard to get, it seems they are manufactured in a few different hardware flavors (but with the same case) and it's hard to tell what flavor you buy.

Right now, I think we've supported the two stk1160 cases, but there's a third Easycap variant currently unsupported (which doesn't use stk1160 but a Somagic chipset).

In addition, given the stk1160 was partly reverse-engineered, partly based on a non-public and very laconic datasheet, it's not easy to fix given the lack of details about the chip.

In conclusion, if you pick stk1160, make sure you buy enough Easycap devices (from the same provider) and do some extra effort to test *each* of them to ensure they work as you expect.

Signature · 3 lines
Ezequiel García, Free Electrons
Embedded Linux, Kernel and Android Engineering
http://free-electrons.com