Gray bars

Holger Eberhard102906

Other Parts Discussed in Thread: TVP5158

We use DVRRDK 03.00.00.00 and a Udworks based hardware design.
We got the following problem:
If no camera is connected at input if the target starts we get gray bars at the bottom of the preview windows.
If the camera is connected and later disconnected the bar does not occur.
We tested flushing the display output channels and swms but the bars seems to be created at capture level.
So we try to find a solution to flush the capture buffer.
we also tested the behavior with blue screen when TVP5158 detects lost lock but the bars also occur in this case.
The bars occur with a black or blue background.
The size of the gray bars seems to be the difference between 720x576 and 720x480.

over 11 years ago

0 Badri Narayanan over 11 years ago

TI__Guru 59700 points

If there is no signal , capture link is configured for NTSC. This will result in capture buffer being allocated for NTSC. with grey patch at bottom corresponding to 576 vs 480 height difference. I think you should modify this behavior such that if there is no signal set to PAL. You can then correctly configure for NTSC at runtime if signal is detected if you are using DVRRDK 4.0 and above which support runtime capture resolution setting.

0 Holger Eberhard102906 over 11 years ago in reply to Badri Narayanan

Genius 4570 points

Ok, I understand, currently I need a fast solution without DVRRDK 4.0.

Is it possible to set PAL resolution as a default in DVRRDK 03.00.00.00 in capture_link ?

0 Holger Eberhard102906 over 11 years ago in reply to Holger Eberhard102906

Genius 4570 points

I forced pObj->isPalMode = TRUE in CaptureLink_drvCreate() and set pScParams->inHeight = 288; and pScParams->outHeight = 288; in CaptureLink_drvInitCreateArgs() but the gray bars still occur. I am not sure how to init for a PAL default size.

We get the standard of the connected cameras via TVP5158 before MCFW API is initialized to avoid problems if camera 0 is not connected. We discussed this solution in http://e2e.ti.com/support/dsp/davinci_digital_media_processors/f/717/p/290387/1013793.aspx#1013793.

0 Badri Narayanan over 11 years ago in reply to Holger Eberhard102906

TI__Guru 59700 points

You will have to modify TVP5158 configuration to output black bar of PAL resolution when no signal is detected.

Share the logs of Vsys_printDetailedStatistics collected 3 times at 1 min interval when you see grey band for confirmation.

0 Holger Eberhard102906 over 11 years ago in reply to Badri Narayanan

Genius 4570 points

22418.teraterm.log

0 Holger Eberhard102906 over 11 years ago in reply to Holger Eberhard102906

Genius 4570 points

Ok, I have a solution for this problem. I will set vidDecVideoModeArgs[i].videoSystem in multich_progressive_vcap_venc_vdec_vdis.c to DEVICE_VIDEO_DECODER_VIDEO_SYSTEM_PAL or DEVICE_VIDEO_DECODER_VIDEO_SYSTEM_NTSC or DEVICE_VIDEO_DECODER_VIDEO_SYSTEM_AUTO_DETECT depending on a former detection of the video standard via TVP5158.

This gives the proper blue screen resolution if cameras are not connected.

Thanks for the support, Best regards

0 Badri Narayanan over 11 years ago in reply to Holger Eberhard102906

TI__Guru 59700 points

From the logs the grey bar is due to the following:

1. Capture channel 0 has valid video signal and is PAL.

2. CaptureLink is configured for isPALMode. This means all capture channels are PAL.

3. Video Signal is not present in channel 1 - N.

4.TVP outputs NTSC solid color when no signal is detected.

5. This causes only 480 lines to be filled by TVP but the SWMS input width is still 576 lines.

6. This causes grey band for remaining 96 lines.

Solutions are:

1. Configure TVP to output PAL when no signal is detected _if_ first channel is PAL (Basically is capture was created for isPALMode).

2. Use DVRRDK 4.0 and configure capture runtime resolution to NTSC for channels which dotn have video to reflect real incoming resolution.

As you don't want to migrate to DVRRDK 4.0 the change you have done is correct.

0 Holger Eberhard102906 over 11 years ago in reply to Badri Narayanan

Genius 4570 points

Thanks for the detailed information.
Migration to DVRRDK 4.x is planed but not for the current used branch.
In future we will use the new features of 4.x, currently we take
the first solution.

Best regards

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Gray bars