How to solve HDMI signal(format 1920x1080 60Hz) from graphic card not display absolute black

Related models

LVP605/LVP615 series/LVP515/LVP909 ect (HDMI input port), LVP7000/LVP609 series(DVI input port)

Phenomenon description

Connect DVI\HDMI signal(format 1920x1080_60Hz) from desktop computer or laptop with processor, output image of processor looks brighter. Even source is all black image, pixels of LED screen light up.

Analysis of cause

First is mechanism of how graphic card read EDID. HDMI input port of LVP615 support almost all resolutions below 1920x1080_60Hz of PC and television video signal format, these information are contained in EDID of corresponding port. After DVI or HDMI output port of graphic card connect with processor, computer read DVI/HDMI EDID data of processor, then output signal supported by processor.

Resolution 1920x1080_60Hz exist in both PC(VESA) and television video format, in general, including RGB Full color (0~255)，RGB Limited color (16~235), YCbCr(4: 4: 4) and YCbCr(4: 2: 2) and other different formats.

If DVI or HDMI port of these models only support one of PC or television standards, then graphic card read corresponding EDID, output only corresponding format, "not absolute black" issue will not occur. But these models support both two standards, after graphic card read EDID information, it will by default output wrong signal format, causing "not absolute black" issue.

Solution

To solve this issue, need to change DVI/HDMI color parameters of graphic card. Commonly, change output settings to RGB Full (0~255) or YCbCr will get things work. Different brands of graphic cards, even different graphic cards of same brands, settings need to be changed are not same. In the following, introduce setup steps using different graphic cards.

Intel Graphic Card 1

Steps:

In desktop mode, right-click the Desktop. Then, select “Intel® Graphics Settings” to enter control panel of Intel graphic card. "Display" - “Information”, select corresponding display(connect with LVP615-HDMI, so select this display).

Under "Color" interface, click checkbox of "YCbCr" to turn it on.

Intel Graphic Card 2

Steps:

In desktop mode, right-click the Desktop. Then, select “Intel® Graphics Settings” to enter control panel of Intel graphic card. "Display" - "General Settings" menu, select corresponding display(connect with LVP615-HDMI, so select this display), under "Quantization Range", click checkbox  of "Full Range". Or under "Color Settings" menu, click checkbox “Enable” of "YCbCr". Both methods can solve issue.

NVIDIA Graphic Card

Steps:

In desktop mode, right-click the Desktop. Then, select "NVIDIA Control Panel", under "Change resolution" menu, select corresponding display(connect with LVP615-HDMI, so select this display), under color settings, select "RGB" for Output Color Format and "FULL" for Output Dynamic range or select YCbCr444、YCbCr422 and "FULL" for Output Dynamic range, then click "Apply".

AMD Graphic Card

Steps:

Right click on your desktop and select AMD Radeon Settings, click on the Radeon Additional Settings, Radeon Additional Settings menu should open up in a separate window. Then enter "My Digital Flat-Panels" - "Pixel Format": change to "RGB 4:4:4 Pixel Format PC Standard(Full RGB)", click "Apply".

Note:interface of different graphic cards maybe not same, please search patiently, if got no relative options, please try to update driver for graphic card.

With the development of tech and market, LED display screen pitch is getting smaller and smaller. And the size is growing bigger and bigger. The led video processors which support ultra resolution cater to this demand and get more and more popular.LVP605 and LVP515, which could control 3840 horizontally or 1920 vertically, are the prominent models.The guide for controlling ultra width or ultra height is shared below.

custom resolution setting range

LVP605 and LVP515 custom max output horizontal width is 3840.And custom output vertical height is 1920.But it is limited by the processor main chip bandwidth. The max output resolution need follow the below formula.

25999000 Hz< Dot Clock < 164999000 Hz

therein，

Dot Clock = Htotal x Vtotal x field frequency,

HTotal = Width + 184，Vtotal = height + 45 ,

Field frequency is 23~80Hz adjustable

From formula above, due to bandwidth limitation, when field frequency is 60Hz, output width can be 3840 pixels and the output height is maximally 638 pixles.When height reach maximum1920, the output width is maximally 1214 pixles. So for super big output resolution, we need decrease field frequency.

Using Limitation

Under super Width or Super height output resolution, main chips of led video processor are working under special circumstances. So,parameters setting has certain limitation. If setting improper, output width and height are more than 1920 pixles. LVP605 and LVP515 series perhaps has below abnormal display images.

the botton line is repeatedly displayed

Bottom image displayed at the top of screen

Not display full input image on the whole screen(Bottom part missing)

This is because ultra width or ultra height output resolution are special working conditions for processor. It has certain limitation. Specifically, when output width and input width are more than 1920 pixels.  processor only works under partly display condition and can not display the full input image.

Solution:

According to the actual led resolutions to choose corresponding custom output format and EDID.

Take 2144*768 led screen for example, we could set the output resolution and custom EDID as 2144*768 60Hz. Therefore, EDID of DVI input port has 2144*768 60HZ output format. and computer graphic card could output corresponding resolution. Then the incomplete display will not happen and could realize clear pitch to pitch display on led screen.

Now. Our processor can output at least 1920*1080HD. And new processors like lvp605 serial and  lvp515 serial can support 2560*816 or 2304*1152 or bigger. Under these situation, we need use 2 sending cards to work together. And how to connect these two sending cards? Many customers do not know how to reach big output format. Here, we will explain step by step.

There are two pcs TS802 which has red button on the cards. Linsn TS801 does not have this button. And two pcs TS801 cannot work together.

Two sending cards work together. We need know which one is card 1 and which one is card 2. We keep the switch on the bottom and do not change the setting. It will be card 1. Like the above pic.

We move the number 1 switch up and number 2 switch down. The card will be named as card2. Like the above pic.

We use one cable to connect card 1 and card 2 together. Pay attention to the turn. The red color on the cable must be at the same side.  The hardware connection is finished. Then we need set the parameters in the led studio

Then we fix two sending cards in our processor like above pic. LVP605 can control 2304*1152pixels screen.

LVP605 serial has LVP605, LVP605S and LVP605D.  Only LVP605S is with SDI input. Different

From LVP603 and LVP603S motherboard structure, the SDI input board of LVP605S is seperated from

the main mother board. Customer can change LVP605 to LVP605S by adding SDI input board. Here, we

Will introduce how to change.

1、Remove the fixed screws of cover

2、Take down the cover

3、Remove the screws which fixed the video input card

4、Remove the fixed PCB screws

5、Take out video board carefully

6、7、Install SDI board

8、Fix the SDI board carefully.

9、10、Fix the screws

11、 Fix the cover screws

1、Under normal working station（NO PIP and MOSAIC），press SETUP to enter menu.  And press UP to item 20.(different version, different item No.)

2、3、4、Press 5 times V1 without stop. Press UP to item 24 (different version, different item NO.)“EXT model VIDEO”。

5、6、7、Adjust the knob to find “EXT model SDI”

8、Press SAVE（knob）to save. SDI input can work now.

Simple Introduction : The screen resolution is 2176*1280.  Customer wanna open different windows to show several SDI input on the screen.  We introduce LVP86XX to customer.

LVP86XX simple introduction: LVP86XX max 7 input cards. And each card has 1* VIDEO, 1*VGA,1* DVI and 1* SDI inputs. So it has 7*SDI,7*DVI, 7*VGA, 7*VIDEO inputs.  LVP86XX has 4 output cards. Each output card supports 4*DVI output(1920*1080). So it has 16*DVI(1920*1080) and can be used to mosaic very big led screen.

Realization:

Out_M  (configuration mode 6)

1 ) Output card Out_M has 4 input channels of In1 In2 In3 and In4, according to the relationship to configure input card to input channel, Input_A to In1, Input_B to In2, Input_C to In3, Input_D to In4.

2 ) Output card Out_M has 4 Output channels of CH1 CH2 CH3 and CH4, according to the relationship to configure input channel to output channel, In1 to CH1, In2 to CH2, In3 to CH3, In4 to CH4.

Out_N  (configuration mode 6)

1 ) Output card Out_N has 4 input channels of In1 In2 In3 and In4, according to the relationship to configure input card to input channel, Input_E to In1, Input_F to In2, Input_G to In3 (Input_G has opened PIP,PIP signal choose DVI), the signal of Out_M loops to In4.

2 ) Output card Out_N has 4 Output channels of CH1 CH2 CH3 and CH4, according to the relationship to configure input channel to output channel, In1 to CH1, In2 to CH2, In3 to CH3, In4 to CH4 (In4= M CH1 + M CH2 + M CH3 + M CH4 = N CH4 = M loop).

Out_L  (configuration mode 6)

1 ) Output card Out_L has 4 input channels of In1 In2 In3 and In4, because Out_L needs to achieve preview, you can configure the signal from ( Input_A, Input_B, Input_C, Input_D, Input_E, Input_F, Input_G) to input channel (In1 In2 In3 In4), which one you want to watch then configure which one.

2 ) Output card Out_L has 4 Output channels of CH1 CH2 CH3 and CH4, according to the relationship to configure input channel to output channel, In1 to CH1, In2 to CH2, In3 to CH3, In4 to CH4.

Out_K  (configuration mode 1)

1 ) Out_K achieves mosaic to drive LED screen (2176 x 1280), the signal from Out_N loops to 4 input channels of Out_K, Out_N to (In1 In2 In3 In4).

2 ) Output card Out_K has 4 Output channels of CH1 CH2 CH3 and CH4, according to the relationship to configure input channel to output channel, In1 to CH1, In2 to CH2, In3 to CH3, In4 to CH4.