Understanding the Enigma2 Blindscan Plugin

[el bandido]

14045

The enigma2 blindscan could be thought of as an user interface for the blndscan bin file that is provided by the receiver manufacturer. The blindscan plugin allows us to set or control some variables such as scan start - scan stop frequencies, or upper and lower symbol rate parameters. The actual blindscan process is mainly controlled by the manufactures blindscan bin file

Actual blindscan speed, or the speed of finding transponders goes pretty quick in enigma2. Problems with overall blindscan speed usually begin when the transponders that are found during the blindscan transponder search are scanned for channels. The Service scan that searches for channels may be extremely fast, or extremely slow. The Service scan was probably designed based on Dreambox receivers that were in production several years ago. The Service scan also has to work for many different brands of receivers.

We may not be able to adjust the Service scan speed in this forum, but we can add features or scan filters to the blindscan plugin to help speed the overall scan time up.Transponders for the satellites are normally stored in the satellies.xml file located in the "etc/tuxbox" folder. When a channel is scanned, transponder information for the channel is stored in the lamedb file located in the "etc/enigma2" folder. Filters may be added in the blindscan plugin to delete the transponders from the blindscan that are found at either of these locations. I see very little need to rescan a transponder that already has channels stored in the receiver for most scans, and fewer transponders that need a Service scan will result in a faster blindscan time.

We may also customize what we search for. Several enigma2 receivers now have 16/32 apsk capabilities, and we can add a filter to blindscan only for 16/32 apsk transponders. Filters are also available that compare the stored transponders for satellites up to 3 degrees away, and delete any duplicate transponders that are in neighboring satellites from the blindscan transponder list.

A while back or a year or two ago, lnbs that have a l.o. of 10750 were added to the blindscan plugin. A few math calculations were needed to do this, along with starting the scan in the blindscan plugin at 11550 MHz so transponders at or near 11700MHz would be found. To use this feature, Circular lnb type must be selected in antenna setup.

Changes to the blidnscan plugin are being made regularly by the developers. Some of the changes help us in North America, while other changes may not really benefit us. As an example, recently all default blndscans except those using the Universal lnb type are set to circular output in the blindscan plugin. Using circular settings in the blindscan plugin for linear satellites will cause scanning issues!

In the past, I have modified the blindscan plugin with features designed for use in North America. However, I see little need to do this now unless the features that I add will be used. I also adjust settings and defaults of the blindscan plugin to my personal wants or likes. I will be glad to help anyone that would like more or different features.

I have uploaded a couple of videos to demonstrate the blindscan. in enigma2 receivers. The first video in the link below shows a blindscan of 97 West Ku, and shows how to properly set the 10750 l.o. in enigma2.
The second video is around 17-18 minutes long and shows the enigma2 blindscan of 105 West C band that yields over 2500 tv and radio services. Enigmna2 is the only system I know of that is capable of blind scanning the 105W satellite and returning this amount of channels in a single scan.

97W_Ku_BS-10750_20170409_0342.ts
[Only registered and activated users can see links]!rhkgWb5Y!ElQAZLrTV1ANm6tj8UTnZbKjR4o_QanGq1FjSt4 Bl80

105W_BS_20170408_1956.ts (522.0 MB)
[Only registered and activated users can see links]!LhlEhRKL!pgslm2sU4oIyM5bBWwDsrwNyKm4UEodbjnrbNZE bA4E





The purpose of this thread is to discuss the use of the blindscan plugin. Anyone that has suggestions, questions, or comments about the blindscan plugin is welcome to post in this thread. EB

[el bandido]

Here is video that shows a search for 16/32 APSK transponders. C band satellites at 101,99,97, and 95 West were searched in the video with 16APSK channels being found at 95W.


16_32_APSK_BS_20170412.ts 331.4 MB
[Only registered and activated users can see links]!Gp8FUTrK!M3kHkbVKahxzEAlLyJIKo0u4jj1Nko4iJMl6k0h 7SLw

[el bandido]

As an example, I deleted all the channels from the enigma2 receiver, and did a blindscan of 105 West Ku band. Channel information is stored in the lamedb file located in the etc/enigma2 folder. The contents of the lamedb file after this blindscan are listed in the quote.


eDVB services /4/
transponders
09f60000:0001:0fa4
s 11826000:7232000:1:0:-1050:0:1
/
09f6adf0:0441:0000
s 11760000:29996000:1:7:-1050:0:1:1:1:0:0
/
09f6ae4f:0001:0001
s 11855000:3546000:1:0:-1050:0:1
/
end
services
0001:09f60000:0001:0fa4:1:0:0
Shaw Sports
p:Shaw Television Mobile,c:0001e1,c:010100,c:0301e1,c:050001,f:40
0004:09f6ae4f:0001:0001:1:0:0
MACYS 4
p:,c:00006e,c:010064,c:03006e,f:40
0006:09f6ae4f:0001:0001:1:0:0
Macy's Core Music
p:,c:01012d,c:03012d,f:40
0007:09f6ae4f:0001:0001:1:0:0
Macy's Contemporary Music
p:,c:01012f,c:03012f,f:40
000c:09f6ae4f:0001:0001:1:0:0
Macy's Hawaii
p:,c:0100ca,c:0300ca,f:40
0010:09f6ae4f:0001:0001:1:0:0
Macy's Backstage
p:,c:010066,c:030066,f:40
5014:09f6adf0:0441:0000:100:0:0
11760V SID 0x5014
p:DVB-S2 QPSK 11760V 255.0°E,c:031fff,f:40
9c40:09f6adf0:0441:0000:100:0:0
11760V SID 0x9c40
p:DVB-S2 QPSK 11760V 255.0°E,c:031fff,f:40
end
Have a lot of bugs!
This particular blindscan returned about 8 channels or services on 3 transponders. The transponders are listed in red in the quote.

If I tell the plugin to ignore or not to blindscan the transponders in lamedb, then the 3 transponders listed in the above quote would not be scanned or saved in the blindscan. (See Screenshot below). I do not see a need to rescan these transponders. BUT if a new channel or service was added to one of these transponders, then that new service or channel would not be found. It should be noted that new services or channels are not added to transponders very often.

14063

[el bandido]

Another filter we can use is not to scan transponders located in satellites.xml for the satellite being scanned.
The satellites.xml file is located in etc/tuxbox, but I usually modify this file and then move it to the etc/enigma2 folder. Moving the satellites.xml file to the etc/enigma2 folder hides this file during online updates so it will not be overwritten or changed during routine image upgrades.

My current satellites.xml file contains these transponders for 105 West Ku.

<sat name="105.0W AMC 15/18 Ku Band" flags="1" position="-1050">
<transponder frequency="11856000" symbol_rate="3548000" polarization="1" fec_inner="0" system="0" modulation="1"/>
<transponder frequency="12123000" symbol_rate="1000000" polarization="0" fec_inner="0" system="0" modulation="1"/>
</sat>


My enigma2 debug log shows these four transponders being found in a 105W Ku blindscan:

[Blind scan] cnt : 10 , data : ['OK', 'VERTICAL', '11760000', '29996000', 'DVB-S2', 'INVERSION_OFF', 'PILOT_OFF', 'FEC_3_5', 'QPSK', 'ROLLOFF_20']
[Blind scan] cnt : 10 , data : ['OK', 'VERTICAL', '11826000', '7232000', 'DVB-S', 'INVERSION_OFF', 'PILOT_OFF', 'FEC_3_4', 'QPSK', 'ROLLOFF_35']
[Blind scan] cnt : 10 , data : ['OK', 'VERTICAL', '11855000', '3546000', 'DVB-S', 'INVERSION_OFF', 'PILOT_OFF', 'FEC_3_4', 'QPSK', 'ROLLOFF_35']
[Blind scan] cnt : 10 , data : ['OK', 'VERTICAL', '12040000', '29994000', 'DVB-S2', 'INVERSION_OFF', 'PILOT_OFF', 'FEC_3_4', '8PSK', 'ROLLOFF_25']
[Blind scan] cnt : 10 , data : ['OK', 'VERTICAL', '12130000', '2498000', 'DVB-S', 'INVERSION_OFF', 'PILOT_OFF', 'FEC_1_2', 'QPSK', 'ROLLOFF_35']

The current blindscan plugin has some routines that check for duplicate transponders. The 11855 transponder listed in the above quote would be discarded and would not be scanned if the blindscan plugin was set to not scan the transponders stored in satellites.xml. (See screenshot below.)
14064

[el bandido]

14065

We can also filter the satellite transponders that are stored in satellites.xml for satellites up to three degrees.
The setting pictured above will filter all transponders that are in satellites.xml from these satellites;

107.4W, "107.3W Anik F1R C Band"
105.1W, "105.0W AMC 15/18 C Band"
103.1W, "103.0W SES 3 C Band"
103.0W, "103.0W SES 3 Ku Band"

The blindscan plugin does not care that three of the satellites listed above are for c band. The plugin will still search those c band satellite entries for transponders that match what is found during the blindscan and will discard any duplicates.

[el bandido]

In the past, one blindscan test for closed source receivers would be to delete all the transponders for a satellite, then do blindscan. Deleting all the transponders that were stored in the receiver was done to keep the receiver from somehow Cheating, and scanning the transponders that were already stored in the receiver's satellite file. Deleting all the stored transponders supposedly demonstrated that the receiver was a "True" or "Hardware" blindscan receiver. IMO, those days are long gone! Doing something like that today makes no sense.

At any Rate, Enigma2 Does Not Work That Way!
The only way you can delete the transponders that are stored in enigma2 is by deleting the transponders that are stored in the receiver's satellite.xml file(s). The satellite.xml file may be stored in one or two locations. Then you would also have the transponders that are stored in the lamedb file that was discussed earlier.

No modern enigma2 receiver that I know of cheats by looking at the stored transponders for a satellite during a blindscan. Trying to delete all the transponder information in an enigma2 receiver would be a waste of time, and could cause the blindscan to have problems. The blindscan plugin looks for transponder information to make decisions on what satellite is being viewed (Motorized Systems), and the correct band to blindscan.
It is simple enough to look at the output of the enigma2 blindscan to determine that it is indeed a "True" blindscan that is not using Smoke and Mirrors.

[el bandido]

14066

A channel file will get all sorts of dead feeds in it if it is used for multiple blindscans over a period of days, weeks, or months. Duplicate channels are a big problem in many closed source receivers when multiple blindscans are done.

We can save our channel information and restore it quickly in enigma2. This allows us to do blindscans or other tasks, then restore the receiver to what we had before we started the tasks. The satellite and channel information is stored under settings. About every enigma2 image will have a feature or a menu similar to what is shown above to save or restore settings.

[el bandido]

Probably the most common l.o. frequency for a linear ku lnb that is used in North America will be 10750 MHz. This was covered in post #1 of this thread, but many get confused on how to make the 10750 lnb blindscan and give the correct frequency output. Here is a quote from the NimManager file.

elif currLnb.lof.value == "circular_lnb":
sec.setLNBLOFL(10750000)
sec.setLNBLOFH(10750000)
sec.setLNBThreshold(10750000)

The meaning of that code is simple: The circular lnb setting in antenna setup has a l.o. of 10750 MHz. I found this bit of code some time ago, and was able to get the 10750 lnb added to most blindscan plugins. Follow these two steps in order to use a 10750 l.o. lnb in blindscan. (1) Select the Circular setting for the lnb in antenna setup, and (2) Make sure you are scanning Horizontal and Vertical transponders in the blindscan plugin menu.

A couple of lines of code were added recently to the blindscan plugin that sets the default polarity to circular instead of Horizontal and Vertical when a Circular lnb type is used in antenna setup. Circular polarities have also been made the default in the blindscan plugin when a C Band lnb is used in antenna setup. Blindscanning with the wrong polarity type will cause problems with the blindscan data or output!

Correct LNB Setting for 10750 L.O.
14069


Correct Polarity Type for Horizontal and Vertical Transponders:
14067


WRONG Polarity Type for Horizontal and Vertical Transponders:
14068

Pay Attention!
Little details will make or break the blindscan data or output.

[el bandido]

I am sure that someone will look at this thread and decide that the blindscan plugin is too complicated, They will say not many people can understand it because it has too many features. For those people, look in the screenshot below.

14080

Not much of a way to get it any simpler than that.
We can set the plugin and many parts of the image to be very simple.

[Megatron817]

I had been just setting the scan stop frequency 12200 for KU but about a week ago I tested 12050 as the stop and it found a channel at 12189 so I now use 12050 as the stop frequency and the blind scan seems faster and more reliable.

[el bandido]

Setting the stop frequency at 12200 should find a transponder at 12189 because 12189 is less than 12200.

Setting the stop frequency at 12050 should not allow a transponder at 12189 to be registered. Here are the code lines in the blindscan plugin that would not let that happen:

if freq >= self.blindscan_start_frequency.value and freq <= self.blindscan_stop_frequency.value and symbolrate >= self.blindscan_start_symbol.value * 1000 and symbolrate <= self.blindscan_stop_symbol.value * 1000:
add_tp = True
else:
add_tp = False

[Megatron817]

That's what I thought but it must be 150mhz off. 12050= 12200
There is a game on 91w Ku at 12120 tonite do a blind scan with 12050 as the stop and see if you get it.
open pli 6.2 release is what i use with VU+ zero 4K.
attached some scans and you can see setting the stop at 11960 did not find tp 12120 where setting the stop at 11975 did find the tp 12120.
that shows it is around 150 mhz off.

[el bandido]

Are you using Circular for lnb type in antenna setup?

[Megatron817]

yes, still using Circular settings.

[el bandido]

I need to think about that a minute, and it is a little late to do that today. But you are correct about the 150 MHz.
The enigma2 plugin thinks the lnb is universal, so we have to trick it to run the standard 10750 lnb... We tell it to start 150 MHz lower--which makes it scan 150 MHz higher... We can add a few lines to the plugin file and fix this. Or run it like it is and understand the problem.

While we are at it, we can fix it where it shows 11700 for a start frequency instead of 11550 in the blindscan logs, but that will take a few more lines of code. Maybe this winter I will have time to go back through the plugin file and fix some of these items.