Hi Thierry,

I'm running the latest commit cf6d072 with the new -b and libacars.
Previous versions have used about 45% of cpu on my Raspberry Pi v3.
When using 'top', this latest version appears to be running at 195% cpu; although I assume it is spread across all cpu's.
Why is the CPU use so high?
Regards
Stuart

When one has multiple dongles connected using the device ID can be confusing.
Please implement the use of serialnumber.
There are several examples on github that have this feature (like dumpvdl2)..

Cheers,
Dick

It is generally accepted that the aircraft identifier/ModeS/ICAO24 e.g. 400dad, and VDL2 ground station identifiers are usually displayed with upper case characters e.g. 400DAD.

Can vdlm2dec be changed accordingly?

A Broadcast Message transmitted from a VDL2 ground station usually contains a local airport name and location e.g a 4 character ICAO code (EGLC) and a latitude and longitude location.
Can vdlm2dec also decode this data and add it as minimum to the "-v 1" normal output logs?

A Broadcast message in vdlm2dec -v 3 format from vdl2 ground station 260F37 EGLC.

ppm -0.2
#5 19/01/2018 11:03:44.292
Command from Ground: 260f37 to: ffffff 
Frame-U: -/- XID
Parameter set ID
Procedure classes
HDLC options
Specific options: VDA:ESN:IHN:BHN:BCN
unknown private id c1
c1 04 45 47 4c 43                                  |..EGLC..........|
unknown private id c4
c4 06 53 49 54 00 00 01                            |..SIT...........|
unknown private id c5
c5 04 94 00 00 00                                  |................|
unknown private id c8
c8 03 20 30 00                                     |.. 0............|
-----------------------------------------------------------------------

The definition is in RTCA DO 224C.

The 4 character ICAO airport code EGLC is fairly obvious!

The latitude and longitude are encoded in the last 3 bytes or your message above e.g. 20 30 00
12 bits for the latitude, 12 bits for longitude.
First bit is sign; 0 = positive = North or East.
If sign = 1 = negative = South or West. Then need twos-compliment.
Remaining 11 bits are the value.
For EGLC latitude value is 515 = 51.5N, longitude = 0 = 0.0E (maybe not the best example to use!)

It looks like there's some kind of header issue with timeval on Alpine Linux.

#34 3.586 [ 15%] Building C object CMakeFiles/vdlm2dec.dir/crc.c.o
#34 3.660 [ 23%] Building C object CMakeFiles/vdlm2dec.dir/d8psk.c.o
#34 4.231 [ 30%] Building C object CMakeFiles/vdlm2dec.dir/label.c.o
#34 4.255 In file included from /vdlm2dec/label.c:5:
#34 4.255 /vdlm2dec/vdlm2.h:47:17: error: field 'tv' has incomplete type
#34 4.255   struct timeval tv;
#34 4.255                  ^~
#34 4.258 In file included from /vdlm2dec/label.c:6:
#34 4.258 /vdlm2dec/acars.h:47:24: error: field 'ts' has incomplete type
#34 4.258          struct timeval ts,tl;
#34 4.258                         ^~
#34 4.258 /vdlm2dec/acars.h:47:27: error: field 'tl' has incomplete type
#34 4.258          struct timeval ts,tl;
#34 4.258                            ^~
#34 4.268 make[2]: *** [CMakeFiles/vdlm2dec.dir/build.make:102: CMakeFiles/vdlm2dec.dir/label.c.o] Error 1
#34 4.270 make[1]: *** [CMakeFiles/Makefile2:73: CMakeFiles/vdlm2dec.dir/all] Error 2
#34 4.270 make: *** [Makefile:130: all] Error 2

No output from vdlm2dec after few hours but instantly got output from acarsdec using rtlsdr.

Hi

When running V2.3 and adding the ground station messages to the command (-G), a segmentation fault is thrown. Is this obsolete? Maybe this can cause problems with -g (gain)? I suppose the readme documentation might need an updated arguments list.

Thanks!

My Raspberry Pi box has 8 character hostname 'acarspi3', that does not fit in the given buffer with the terminating null character. In principle hostname() function should care of that, but the glibc implementation has an undefined behaviour in this case and omits the terminator, resulting garbage as station id in JSON output. The following modification solved the issue:

char sys_hostname[9];
sys_hostname[sizeof(sys_hostname) - 1] = '\0';
gethostname(sys_hostname, sizeof(sys_hostname) - 1);

Dates are not is standard format and not easily machine-sortable.

current notation:

[#1 (F:136.725 P:-0.9) 08/10/2018 17:44:41.050

Better to start each line with a ISO8601-compliant date:

2018-10-08T17:44:41,050 [#1 (F:136.725 P:-0.9)

That way we can sort and purge log files very easily, and still keep good human redability.

Hi Thierry,
This evening I upgraded using git pull which showed:
78b23c5..7dc3a78 master -> origin/master

• [new tag] v2.1 -> v2.1
  Updating 78b23c5..7dc3a78

I added the -G option which makes the command that is run from a .sh script looks like this:
/home/pi/vdlm2dec/vdlm2dec -v -G -j 176.9.123.123:60003 -l "/home/pi/vdlm2dec/logs/vdl2_rtlsdr-11_$(date +"%Y%m%d").log" -p -1 -r 00000011 136.725 136.775 136.825 136.875 136.975 >> "/home/pi/vdlm2dec/logs/process-vdlm2dec.log" 2>&1 &

The .sh script is coded so that it will restart the program when it fails.
The last few hours it has failed and restarted 6 times..
The previous version ran 24/7 without any problems.

I can't find anything in any of the logfiles.

Let me know if I can be of any help.

Cheers,
Dick

Would it be possible to implement this acarsdec feature also in vdlm2dec?

-n ipaddr:port : send acars messages to addr:port via UDP in planeplotter compatible format

Cheers,
Dick

Hi Thierry,
As well as the normal acars data, you have included an additional packet in the JSON outputs (-j and -J) containing the destination. For completeness would it be possible to enhance the JSON outputs (-j and -J) to include all aviation related data for all messages e.g. Aircraft ICAO, Ground Station Id, Direction/Uplink/Downlink indicator, Location (Lat & Lon), altitude and destination.

Examples.

[#5 (F:136.975 P:-6.6) 08/02/2018 00:00:13.620 --------------------------------
Response from Aircraft:987654 (airborne) to GroundD:214A77
Frame-S: Nr:1 RR

JSON output would include Date, Time, Channel, Frequency, Aircraft ICAO, Ground Station Id, Direction/Uplink/Downlink indicator.

[#5 (F:136.975 P:-4.7) 08/02/2018 00:01:40.879 --------------------------------
Command from Aircraft:3C66B8 (airborne) to GroundD:10980A
Frame-U: XID
Connection management: HO|VDA|ESN
XID sequencing 0:3
Specific options: GDA:ESN:IHS:BHN:BCN
Destination airport EGCC
Aircraft Position 51.3 4.0 alt: 36000

JSON output would include Date, Time, Channel, Frequency, Aircraft ICAO, Ground Station Id, Direction/Uplink/Downlink indicator, Latitude, Longitude, Altitude and Destination.

Thanks
Stuart

Inside of in_callback() the IQ values get adjusted by 127.37..

How did you determine this is a correct value to adjust them?

Thanks.

static void in_callback(unsigned char *rtlinbuff, uint32_t nread, void *ctx)
{
..
	for (i = 0; i < RTLINBUFSZ;) {
		float r, g;
		r = (float)rtlinbuff[i] - **(float)127.37;**
		i++;
		g = (float)rtlinbuff[i] - **(float)127.37;**
		i++;
		Cbuff[i / 2] = r + g * I;
	}
..
}

My RPi uses timezone Amsterdam which is CEST.
The current version of vdlm2dec logs the messages in UTC but creates a new logfile at midnight CEST.
Please create a new logfile at midnight UTC.

Thanks,
Dick

The CMakeLists.txt is only looking for libacars, and not libacars-2 (which is the latest from https://github.com/szpajder/libacars )

This diff will check for acars-2, first, and then acars, before giving up on that library.

(Forgive the indenting, please adjust as you'd like)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index c619ab7..b86ea58 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -5,13 +5,20 @@ add_compile_options(-Ofast -march=native )

 add_executable(vdlm2dec cJSON.c  crc.c  d8psk.c  label.c  main.c  outacars.c  out.c  outxid.c  rs.c  vdlm2.c  viterbi.c )

-find_library(LIBACARS acars)
-if(LIBACARS)
-message ( STATUS "Using libacars")
-add_definitions(-DHAVE_LIBACARS )
-target_link_libraries( vdlm2dec acars)
+find_library(LIBACARS2 acars-2)
+if(LIBACARS2)
+       message ( STATUS "Using libacars-2")
+       add_definitions(-DHAVE_LIBACARS )
+       target_link_libraries( vdlm2dec acars-2)
 else()
-message ( STATUS "Not using libacars")
+       find_library(LIBACARS acars)
+       if(LIBACARS)
+               message ( STATUS "Using libacars")
+               add_definitions(-DHAVE_LIBACARS )
+               target_link_libraries( vdlm2dec acars)
+       else()
+               message ( STATUS "Not using libacars (v1 or v2)")
+       endif()
 endif()

 option(rtl "Compiling for rtl sdr" )

Sometimes the udp feed just stops working, until the process is killed and re-started. It can work for 30 days and suddenly stop. Local decoding and logging to text file continues normally.

As there is no state of a UDP connection that can be monitored it is hard to detect and restart.

command line is

/usr/local/bin/vdlm2dec -l /var/log/vdlmlog.txt -g 430 -p 60 -i P-ESSN9-V -j 176.9.123.123 60003 -G -r 1 136.725 136.775 136.825 136.875 136.975

Using vdlm2dec, I'm receiving acars messages similar to ...

[#5 (F:136.975 P:-5.2) 01/02/2018 06:35:57.089 --------------------------------
Command from Aircraft:4B17E5 (airborne) to GroundD:10902A 
Frame-I: Ns:5 Nr:4
ACARS
Aircraft reg: HB-JBH Flight id: LX0450
Mode: 2 Msg. label: H1
Block id: 7 Ack: !
Msg. no: 701A
Message :
#T7B- R001
ACARS Header
 HB-JBH,5318410-02,649537,200637,01631,LSZH,EGLC,06:13:14,2018:02:01,00000000
000010,152000
    0.76 (06:21:35)
0.000,0.000,0.000,0.000,03b15,03aa5,00001,0.312,0.000,21.984,22.727,00001

Block End

and ...

[#5 (F:136.975 P:-5.2) 01/02/2018 06:36:14.522 --------------------------------
Command from Aircraft:4B17E5 (airborne) to GroundD:10902A 
Frame-I: Ns:1 Nr:0
ACARS
Aircraft reg: HB-JBH Flight id: LX0450
Mode: 2 Msg. label: H1
Block id: 1 Ack: !
Msg. no: 701E
Message :
#T7B99.625,98.578,159.688,70.375,2.844,2.250,535.562,530.812,124.953,130.031
101.781,97.516,99.750,102.250,-113.000,-54.000,88.250,88.250,1800.000,1869.500
397.500,386.500,1674.000
ACARS Footer:  

I assume that the text 'ACARS' defines the start of an acars message, but what are 'ACARS Header' and 'ACARS Footer'? Are they part of the actual aircraft acars message or debug information? Can they be removed?

Likewise there are number of messages that end with a 'Block End' text. Is this part of the acars message or debug info?

Stuart

My airspy only supports 10 and 2.5MSPS, but in vdl2.h I see:

#define SDRINRATE 5000000
#define SDRCLK 1250

So when I build for airspy and run, it says it can't find the requested scan rate. Using what you did for the Mini, I tried 2500000/625 and commented out the two calls to airspy_r820t_write() and now it opens the device, but doesn't seem to decode any data?

`$ airspy_info
airspy_lib_version: 1.0.7

Found AirSpy board 1
Board ID Number: 0 (AIRSPY)
Firmware Version: AirSpy NOS v1.0.0-rc1-2-g64b62c3 64b62c3-dirty 2014-11-24
Part ID Number: 0x6906002B 0x00000030
Serial Number: 0x440464C83868664F
Supported sample rates:
10.000000 MSPS
2.500000 MSPS
Close board 1`

./vdlm2dec -a -r 0 136.725 136.775 136.875 136.975
Read async -1

The above error appears and does not allow the program to start.
The other 3 on the web page work without any problems.
-a appears to be the problem ?????

Hi,
The current version which I downloaded and compiled this morning does not decode at all..
The most simple variant
./vdlm2dec -r 11 136.975

Found 1 device(s):
0: Realtek, RTL2838UHIDIR, SN: 00000011

Using device 0: Generic RTL2832U OEM
Found Rafael Micro R820T tuner
Tuner gain : 49.600000
Set center freq. to 137025000Hz
Exact sample rate is: 2000000.052982 Hz

Does not result in any decodes..
I suppose you already know that, but just to be sure.....

Maybe you can start using the 'Master' and 'Unsafe' feature in Github. That way one can always easily fallback to the Master (working) version.

[#1 (F:136.975 P:-20.2) 08/09/2018 22:36:08.327 --------------------------------
Command from Aircraft:344583 (airborne) to GroundD:10F65A
Frame-I: Ns:3 Nr:6
unknown data

or

[#1 (F:136.975 P:-21.7) 08/09/2018 22:35:53.483 --------------------------------
Response from GroundD:10F65A (on ground) to Aircraft:3C5EED
Frame-S: Nr:4 RR

I reiceive more and more lines like these above.
Can I have the choice to store the data (or a track of it) in the database's acarsserv? I use your software and it's great!

Trying to use the -g attribute but so far failed.
Tried different places in the string like:
/home/pi/vdlm2dec/vdlm2dec -g 280 -r 00000011 136.725 136.775 136.875 136.975
/home/pi/vdlm2dec/vdlm2dec -r 00000011 -g 280 -p -1 136.725 136.775 136.875 136.975
etc.

I always get warnings and/or only the "usage" display.

The JSON outputs (-j and -J) have the aircraft ICAO code included as a decimal value. It would be clearer to include the icao code as it's normally displayed as a Hex character string e.g. 400DAD ?

Stuart

Not sure how high priority this is, but unlike acarsdec, vdlm2dec doesn't compile without modification since macOS Darwin doesn't implement POSIX thread barriers. There seem to be projects out there that have implemented this functionality easily themselves to avoid this compatibility issue, and thought it might be great if new users could just compile without problems.

This project for instance implemented pthread barriers to fix the compatibility issue:
pmwkaa/ioarena#10

Another example implementation:
https://github.com/ademakov/DarwinPthreadBarrier

References to pthread_barrier_t:

vdlm2.h:88:8:
extern pthread_barrier_t Bar1, Bar2;

main.c:187:2:
pthread_barrier_init(&bar1, NULL, nbch + 1);

main.c:188:24:
pthread_barrier_init(&Bar2, NULL, nbch + 1);

Also noticed that the build throws an error on the use of the undeclared identifier "HOST_NAME_MAX"

main.c:98:27: error: use of undeclared identifier 'HOST_NAME_MAX'
char sys_hostname[HOST_NAME_MAX+1];

Installed the Latest commit 45c3248 from scratch
and using these options
/home/pi/vdlm2dec/vdlm2dec -v -j 176.9.123.123:60003 -l "/home/pi/vdlm2dec/logs/vdl2_rtlsdr-11_$(date +"%Y%m%d").log" -p -1 -r 00000011 136.725 136.775 136.825 136.875 136.975
Found 1 device(s):
0: Realtek, RTL2838UHIDIR, SN: 00000011

Using device 0: Generic RTL2832U OEM
Found Rafael Micro R820T tuner
Tuner gain : 49.600000
Set center freq. to 137025000Hz
Exact sample rate is: 2000000.052982 Hz

the program aborts with errors like these:
75
Read async -1

pi@MYPI-16B:~/vdlm2dec $ vdlm2dec: no process found
75
Read async -1

pi@MYPI-16B:~/vdlm2dec $ 100
Read async -1

I'm an aviation enthusiast, not a C developer.

Issue 1
No mention of the -v options in the README although they appear in usage()
The -v output options shows 3 values 0, 1 & 2. Source code allows for an additional 4th option "-v 3". What is this?

Issue 2
Need to add a date and time stamp (in UTC) to every message for all output formats.

Issue 3
I'd prefer the frequency in place of the channel number. See issue on the 'acarsdec' Github.

Issue 4
The aircraft 6 character identifier (ModeS/ICAO24) appear to be incorrect. Example ...

#1 Command from Aircraft: 50a130 to: 08100a
Frame-I: -/- Ns:4 Nr:6
ACARS
Aircraft reg: G-EZFN Flight id: U229PF
Mode: 2 ......

The message above shows the aircraft registration as G-EZFN. According to look-up sites the Identifier/ModeS/ICAO24 for G-EZFN should be 406130. You have 50a130.

Issue 5
A VDL2 broadcast message from a ground station e.g.

#5 Command from Ground: 278f37 to: ffffff
Frame-U: -/- XID
Parameter set ID
Procedure classes
HDLC options
.....

shows the ground station id as 278f37. This is my local EGLC ground station which should have an id of 260F37

Issue 6
For broadcast messages, other VDL2 decoding software decode the the data in the broadcast message e.g.
Name: EGLC
Location: 51.5N 0.0E

Issue 7
Add a UDP output. There have been various discussions regards UDP output for 'acarsdec' on Github. Maybe similar for this application.

Stuart

As discussed previously, and acarsdec issue #22, is it possible to include the received frequency in both the -j and -J JSON outputs.
Thanks
Stuart

Hi

I would like to request the following arguments to synchronise them with your acarsdec software:

1. possibility to have daily and hourly log files. I did not get the sql server up and running, so now I am logging the messages daily in json format instead. Arguments; -D and -H

2. possibility to change the sample rate to reduce CPU load. Like with the latest acarsdec files, you can pass the sample rate to the software.

Thanks!

The readme and help state:
-g gain : set rtl preamp gain in tenth of db (ie -g 90 for +9db).

In acarsdec this attribute mentions:
-g gain : set rtl preamp gain in tenth of db (ie -g 90 for +9db). By default use maximum gain
Based on the messages vdlm2dec displays at startup
"Tuner gain : 49.600000"
I assume the "By default use maximum gain" is also true for vdlm2dec.

Hi Thierry,
Not sure how to contact you directly, so I just created an "issue" ;-)
You mention "decode more vdlm2 protocols (looking for info)"
Have you seen the dumpvdl2 project of Tomasz?
He has implemented a lot of messages as well as multiple freq decoding.
I have been running it for several months now and also went to EHAM to catch upload and broadcast messages.

Cheers,
Dick

The current logging mechanism creates a log file when vdlm2dec starts, and continues to append to it until the application is stopped.
Would it be possible to enhance the logging option so that a new file is created at midnight UTC so that we get daily log files. (also applies to acarsdec) e.g. 20180120.txt, 20180121.txt etc.

When you view a vdlm2dec log it shows the received channel number.
Is it possible that the received frequency could be be included in the output logs (similar to acarsdec) in addition to the channel number?

Hello,

First of all - thank you for your efforts in developing this great software.
Is it possible to also add support for AirSpy MINI - it differs from the regular AirSpy R2 in terms of the supported sample rates:

### Regular AirSpy R2
Board ID Number: 0 (AIRSPY)
Firmware Version: AirSpy NOS v1.0.0-rc10-3-g7120e77 2018-04-28
Supported sample rates:
	10.000000 MSPS
	2.500000 MSPS

### AirSpy MINI
Board ID Number: 0 (AIRSPY)
Firmware Version: AirSpy MINI v1.0.0-rc10-3-g7120e77 2018-04-28
Supported sample rates:
	6.000000 MSPS
	3.000000 MSPS

I was able to compile and run vdlm2dec by changing SDRINRATE in file "vdlm2.h" from "5000000" to "6000000", but not sure this is the only change that is needed.

#ifdef WITH_AIR
#define SDRINRATE 6000000
#define SDRCLK  1250
#endif

Thanks in advance!

When I start vdlm2dec this way:
/home/pi/vdlm2dec/vdlm2dec -v 2 -r 11 -p -1 136.725 136.775 136.825 136.875 136.975 -l "/home/pi/vdlm2dec/logs/vdl2_rtlsdr-11.log" >> "/home/pi/vdlm2dec/logs/process-vdlm2dec.log" 2>&1 &

The program starts and works as expected but gives 4 warnings:
Found 1 device(s):
0: Realtek, RTL2838UHIDIR, SN: 00000011

Using device 0: Generic RTL2832U OEM
Found Rafael Micro R820T tuner
Tuner gain : 49.600000
WARNING: Invalid frequency 0
WARNING: Invalid frequency -1000000
WARNING: Invalid frequency 0
WARNING: Invalid frequency 0
Set center freq. to 137025000Hz
Exact sample rate is: 2000000.052982 Hz

2 of the warnings go away when I remove the "-p -1" part like this:
/home/pi/vdlm2dec/vdlm2dec -v 2 -r 11 136.725 136.775 136.825 136.875 136.975 -l "/home/pi/vdlm2dec/logs/vdl2_rtlsdr-11.log" >> "/home/pi/vdlm2dec/logs/process-vdlm2dec.log" 2>&1 &

All warnings go away if the arguments are move to another place like this:
/home/pi/vdlm2dec/vdlm2dec -v 2 -l "/home/pi/vdlm2dec/logs/vdl2_rtlsdr-11.log" -p -1 -r 00000011 136.725 136.775 136.825 136.875 136.975 >> "/home/pi/vdlm2dec/logs/process-vdlm2dec.log" 2>&1 &

Cheers,
Dick

Hi Thierry,

The -i command line option is not working.

With my limited knowledge of c, I think the problem is in main.c
getopt(argc, argv, "vqrp:g:l:Jj:iGEU"))

Should the 'i' have a colon after it so that reads the station id argument?

Stuart

The "Command from Ground: 3C4AAB to 214AB7 " suggest that 3C4AAB is a ground station, which is not the case.
A compare with the dumpvdl2 log shows that the aircraft reports an "on the ground" status.

vdlm2dec message:
[#5 (F:136.975 P:-5.1) 25/01/2018 12:01:10.361 --------------------------------
Command from Ground: 3C4AAB to 214AB7
Frame-I: Ns:0 Nr:0
ACARS
Aircraft reg: D-ABUK Flight id: DE2062
Mode: 2 Msg. label: Q0
Block id: 5 Ack: !
Msg. no: S24A
Message :

Same message but now from dumpvdl2:
[2018-01-25 12:01:10 GMT] [136.975] [-45.6/-52.3 dBFS] [6.7 dB]
3C4AAB (Aircraft, On ground) -> 214AB7 (Ground station): Command
AVLC type: I sseq: 0 rseq: 0 poll: 0
ACARS:
Reg: .D-ABUK Flight: DE2062
Mode: 2 Label: Q0 Blk id: 5 Ack: ! Msg no.: S24A
Message:

gcc -Ofast -Wall -pthread -D WITH_RTL -I /usr/local/include/librtlsdr -c -o label.o label.c
label.c:5:22: fatal error: acarsdec.h: No such file or directory
#include "acarsdec.h"

Apparently some acardec files are needed/referenced..

Would it be possible to enhance vdlm2dec messages to include whether an id is an aircraft (and it's status) or a ground station? I think this information is avilable to you when decoding the VDL2 message.
As an example the current message format shows
Command from : 406CD0 (on ground) to : 10919A

Could this be changed to show something similar to
Command from : 406CD0 (aircraft, on ground) to : 10919A (ground station)
or
Command from : 406CD0 (aircraft, airborne) to : 10919A (ground station)
or
Command from : 10919A (ground station) to : 406CD0 (aircraft, on ground)
or
Command from : 10919A (ground station) to : 406CD0 (aircraft, airborne)

Thanks
Stuart

Hey @TLeconte,

I'm building some packages for vdlm2dec and acarsdec for inclusion on ReceiverOS (previously AROS, a project from https://github.com/airframesio). Do you think we can start adding version tags on the repository again? I'd like to be able to properly version the packages against known releases.

Thanks!

Hi Thierry,
Found a couple of these messages in the log using version V2.0 (ab8896d)
Observe the "T0" between "to" and ":0A0010"..

[#5 (F:136.975 P:-3.9) 02/02/2018 11:02:16.690 --------------------------------
Response from Aircraft:AA6C50 (airborne) to T0:0A0010
Frame-U: DM

Dumpvdl2 shows them with a status "Reserved".
[2018-02-02 11:02:16 GMT] [136.975] [-42.1/-51.8 dBFS] [9.6 dB]
AA6C50 (Aircraft, Airborne) -> 0A0010 (reserved): Response
AVLC: type: U (DM) P/F: 0

Cheers,
Dick

Hi Thierry,

The JSON UDP -j output is currently truncating UDP packets at 500 bytes.
I'm not an expert in using 'c' , but found in 'out.c' there was a line which reads
char pkt[500];.
So I changed my copy to 1000, recompiled and it worked -- until I got a UDP packet that was greater than 1000 bytes!!
The message had an acars message of 985 characters; when you add the preceding data in JSON format it broke the 1000 barrier.
I know in traditional (analogue/2400bps) acars messages the maximum length of the acars message is 220 bytes. Is there a corresponding maximum length (1024?) defined for VDL2 processing?

Regards
Stuart

Hi,

Any chance you could support SDRPlay or SoapySDR APIs?

Thanks!

Hi Thierry,

The master shows 2.1 but the program displays 2.0.
And in your last commit it seems you have changed it back from 2.1 to 2.0

Cheers,
Dick

The code in outacars.c for int outacars(flight_t *fl,unsigned char *txt, int len) looks like this:

if(oooi.epu) {
    fl->oooi.epu=oooi.epu;
    fl->oooi.lat=oooi.lat;
    fl->oooi.lat=oooi.lon;
}

Should set oooi.lon, not oooi.lat, on the last line.

Is it possible to output multiple UDP such as -j 192.168.1.2:8880 -j feed.acars.io:5550

Hi Thierry,

My vdlm2dec command line has the first frequency defined as 136.725.
The default log file output shows this as

[#1 (F:136.725 P:-1.5) 10/02/2018 ..... i.e <channel 1>

The equivalent JSON output shows as "

channel":0,"freq":136.725, ..... i.e. <channel 0>

The default log file appears to show the channel number as base 1. The JSON output appears to be base 0.
Both outputs are independant so it doesn't really make any significant difference, but would it be better for consistency if they were both base 0 or 1?

I haven't checked yet if this also applies to acarsdec.
edit -- same applies to acarsdec
Regards
Stuart

Hi Thierry,

I've found some JSON format error / duplicated acars output in the JSON output.
There are 2 examples below. I've included them in this 1 Github issue as I suspect that are all closely linked to one area of the source code.

The examples include the default log file output and the equivalent JSON output.

Example 1

BA018F (Msg No M33A) sent an FST01 message.
There were then 2 acars messages without an actual acars message.
Then BA13GV (Msg. no: D00A) sent a long H1 acars message.

[#4 (F:136.875 P:1.8) 14/02/2018 15:14:47.266 --------------------------------
Command from Aircraft:400D89 (airborne) to GroundD:262243 
Frame-I: Ns:2 Nr:1
ACARS
Aircraft reg: G-MEDL Flight id: BA018F
Mode: 2 Msg. label: 15
Block id: 9 Ack: !
Msg. no: M33A
Message :
FST01EGLLEGPDN052435W0007268236  94  16- 3C 61273      388  16071514

[#5 (F:136.975 P:-2.4) 14/02/2018 15:14:47.282 --------------------------------
Command from Aircraft:3C5EF4 (airborne) to GroundD:10983A 
Frame-I: Ns:5 Nr:5

[#5 (F:136.975 P:-2.1) 14/02/2018 15:14:47.788 --------------------------------
Command from Aircraft:461F30 (airborne) to GroundD:214AB7 
Frame-I: Ns:6 Nr:7

[#5 (F:136.975 P:-4.7) 14/02/2018 15:14:48.314 --------------------------------
Response from Aircraft:406230 (airborne) to GroundD:260F37 
Frame-U: DM

[#4 (F:136.875 P:1.9) 14/02/2018 15:14:48.577 --------------------------------
Response from Aircraft:400D89 (airborne) to GroundD:262243 
Frame-S: Nr:2 RR

[#5 (F:136.975 P:-2.0) 14/02/2018 15:14:49.101 --------------------------------
Response from Aircraft:461F30 (airborne) to GroundD:214AB7 
Frame-S: Nr:0 RR

[#5 (F:136.975 P:-0.4) 14/02/2018 15:14:50.165 --------------------------------
Command from Aircraft:4074B0 (airborne) to GroundD:10902A 
Frame-I: Ns:0 Nr:3
ACARS
Aircraft reg: G-EZRR Flight id: U289DM
Mode: 2 Msg. label: _d
Block id: 4 Ack: O
Msg. no: S87A
Message :


[#2 (F:136.775 P:-3.6) 14/02/2018 15:14:50.819 --------------------------------
Response from Aircraft:4BAA6B (airborne) to GroundD:275D25 
Frame-S: Nr:2 RR

[#5 (F:136.975 P:-4.2) 14/02/2018 15:14:50.836 --------------------------------
Response from Aircraft:3C5EF5 (airborne) to GroundD:10914A 
Frame-S: Nr:5 SREJ

[#5 (F:136.975 P:-2.2) 14/02/2018 15:14:50.885 --------------------------------
Response from Aircraft:3C5EF4 (airborne) to GroundD:10983A 
Frame-S: Nr:6 RR

[#5 (F:136.975 P:-2.2) 14/02/2018 15:14:51.065 --------------------------------
Command from Aircraft:3991E9 (airborne) to GroundD:10919A 
Frame-I: Ns:6 Nr:7
ACARS
Aircraft reg: F-HEPJ Flight id: AF1069
Mode: 2 Msg. label: _d
Block id: 7 Ack: B
Msg. no: S46A
Message :


[#4 (F:136.875 P:-3.8) 14/02/2018 15:14:51.625 --------------------------------
Command from Aircraft:406B5B (airborne) to GroundD:261EE1 
Frame-I: Ns:6 Nr:5
ACARS
Aircraft reg: G-GATL Flight id: BA13GV
Mode: 2 Msg. label: H1
Block id: 1 Ack: !
Msg. no: D00A
Message :
#DFBA04/A32004,1,4/CCG-GATL,FEB14,151421,EGKK,LSGG,0000/
C105,18500,4000,03,0100,0,0110,03,X/
CE0067,00701,158,242,6259,303,I20A10/
EC011288,44532,25676,23/
EE017312,08989,04610,23/
N101,13,01,04,07,47,52,65,4795,4800/
N201,13,01,04,08,45,54,64,4620,4630/
S11305,4790,0813,0886,3594,1426,1305/
S21305,4615,0814,0882,3472,1427,1307/
T13465,4665,032,14914,0071,20003/
T23543,4620,025,14906,0071,19921/
V103D01,00404,08000,239,084,0003,1,1/
V203D01,00404,08000,245,084,0005,1,1/
V3011,002,182,XXX,0349,0/
V4002,002,296,XXX,0350,0/

The equivalent JSON output shows

{"timestamp":1518621287.27252,"station_id":"Pi3","channel":3,"freq":136.875,"icao":4197769,"mode":"2","label":"15","block_id":"9","ack":"!","tail":"G-MEDL","flight":"BA018F","msgno":"M33A","text":"FST01EGLLEGPDN052435W0007268236  94  16- 3C 61273      388  16071514","depa":"EGLL","dsta":"EGPD"}
{"timestamp":1518621290.1720109,"station_id":"Pi3","channel":4,"freq":136.975,"icao":4224176,"mode":"2","label":"_d","block_id":"4","ack":"O","tail":"G-EZRR","flight":"U289DM","msgno":"S87A"}
{"timestamp":1518621291.0586081,"station_id":"Pi3","channel":4,"freq":136.975,"icao":3772905,"mode":"2","label":"_d","block_id":"7","ack":"B","tail":"F-HEPJ","flight":"AF1069","msgno":"S46A"}
{"timestamp":1518621291.615262,"station_id":"Pi3","channel":3,"freq":136.875,"icao":4221787,"mode":"2","label":"H1","block_id":"1","ack":"!","tail":"G-GATL","flight":"BA13GV","msgno":"D00A","text":FST01EGLLEGPDN052435W0007268236  94  16- 3C 61273      388  16071514","depa":"EGLL","dsta":"EGPD"}

The long BA13GV H1 message has been replaced with the original BA018F FST message and the json format has been corrupted to show "text":FST01EGLL . It's missing the " at the start of the FST message.

Example 2

AC0855 (Msg No D74M) sent a message starting with #DFB37 13 12 12 131334
There were then 2 acars messages without an actual acars message.
Then W609AY (Msg. no: D02A) sent a H1 acars message with #DFBA321,007163,1,1,TB0.

[#1 (F:136.725 P:-0.2) 14/02/2018 14:49:11.506 --------------------------------
Command from Aircraft:C023BD (airborne) to GroundD:11983A 
Frame-I: Ns:5 Nr:4
ACARS
Aircraft reg: C-FNNW Flight id: AC0855
Mode: 2 Msg. label: H1
Block id: 6 Ack: !
Msg. no: D74M
Message :
#DFB37 13 12 12 131334
002211  0  01001000045474532 13 12 12 131332
002211  0  01001000045314529 13 12 12 131331

[#5 (F:136.975 P:-2.3) 14/02/2018 14:49:11.571 --------------------------------
Response from Aircraft:4408D7 (airborne) to GroundD:10983A 
Frame-S: Nr:7 RR

[#5 (F:136.975 P:-1.1) 14/02/2018 14:49:11.833 --------------------------------
Command from GroundD:260F37 (on ground) to Aircraft:406099 
Frame-I: Ns:0 Nr:1

[#4 (F:136.875 P:-2.6) 14/02/2018 14:49:12.359 --------------------------------
Response from Aircraft:461F65 (airborne) to GroundD:262242 
Frame-S: Nr:4 RR

[#5 (F:136.975 P:-1.7) 14/02/2018 14:49:13.111 --------------------------------
Command from Aircraft:A4E822 (airborne) to GroundD:10983A 
Frame-I: Ns:3 Nr:3
ACARS
Aircraft reg: N415QS Flight id: GS415Q
Mode: 2 Msg. label: _d
Block id: 2 Ack: K
Msg. no: M60A
Message :


[#1 (F:136.725 P:-0.1) 14/02/2018 14:49:13.653 --------------------------------
Response from Aircraft:C023BD (airborne) to GroundD:11983A 
Frame-S: Nr:5 RR

[#5 (F:136.975 P:-0.5) 14/02/2018 14:49:13.995 --------------------------------
Command from Aircraft:40612C (airborne) to GroundD:10987A 
Frame-I: Ns:3 Nr:3

[#1 (F:136.725 P:-2.3) 14/02/2018 14:49:14.800 --------------------------------
Command from Aircraft:4400B9 (airborne) to GroundD:11909A 
Frame-I: Ns:3 Nr:5

[#5 (F:136.975 P:-0.9) 14/02/2018 14:49:14.864 --------------------------------
Command from Aircraft:4B18F4 (airborne) to GroundD:10983A 
Frame-I: Ns:7 Nr:3

[#5 (F:136.975 P:-1.1) 14/02/2018 14:49:14.962 --------------------------------
Command from GroundD:29D1D7 (on ground) to Aircraft:4401DC 
Frame-I: Ns:7 Nr:2

[#5 (F:136.975 P:-1.3) 14/02/2018 14:49:15.077 --------------------------------
Command from GroundD:29D1D7 (on ground) to Aircraft:FFFFFF 
Frame-U: XID
Specific options: VDA:ESN:IHN:BHN:BCN
Airport coverage : EGSS 
ATN router nets : ADM: 534954 ARS : 000001
Station system mask : 200000
Station Position 51.9   0.3

[#1 (F:136.725 P:0.9) 14/02/2018 14:49:15.094 --------------------------------
Command from Aircraft:40600F (airborne) to GroundD:1191EA 
Frame-I: Ns:0 Nr:0
ACARS
Aircraft reg: G-EZTE Flight id: U214MX
Mode: 2 Msg. label: Q0
Block id: 1 Ack: !
Msg. no: S78A
Message :


[#1 (F:136.725 P:-2.1) 14/02/2018 14:49:15.177 --------------------------------
Command from Aircraft:3C65C4 (airborne) to GroundD:11983A 
Frame-I: Ns:5 Nr:1

[#5 (F:136.975 P:-1.5) 14/02/2018 14:49:15.651 --------------------------------
Command from Aircraft:471F73 (airborne) to GroundD:2651D7 
Frame-I: Ns:3 Nr:4
ACARS
Aircraft reg: HA-LXR Flight id: W609AY
Mode: 2 Msg. label: H1
Block id: 2 Ack: !
Msg. no: D02A
Message :
#DFBA321,007163,1,1,TB000000/REP048,00,00,1/HA-LXR,14FEB18,144905,EGGW,EPKT,W60009/TIA05WIZ090501,01,  5.00,  6.25/HA14133718,134309,14134341,134638/HB14143142,143320,14143454,14144846,1/AA134139,0,134703,0/AB141007,0,144117,0/AC000000,0,000000,0/AD000000,0,000000,0/KA134143,0,134700,0/KB141015,0,144117,0/KC000000,0,000000,0/KD000000,0,000000,0/BA141020,144018,  8.38,  4.75/BB000000,000000,  0.00,  0.00/BC000000,000000,  0.00,  0.00/BD000000,000000,  0.00,  0.00/CA134653,0,142718,0/CB000000,0,000000,0/CC000000,0,000000,0/CD000000,0,000000,0/DA134700,0,141015,0/DB000000,0,000000,0/DC000000,0,000000,0/DD000000,0,000000,0/EA000/EB000/EC000/ED035/EE035/EF029/EG023/EH040/FA01146,03157/FB01146,03159/FC07099/GA0139/MA  527/NA  51.8804, 0.000168/PA-  0.3746, 0.000092/QA035,000/RA 19.75, 19.00, 19.50, 18.75/SA1433,1469/TA135018,0,141153/UA135022,0,141146,  8440/:

The equivalent JSON output shows

{"timestamp":1518619751.496139,"station_id":"Pi3","channel":0,"freq":136.725,"icao":12592061,"mode":"2","label":"H1","block_id":"6","ack":"!","tail":"C-FNNW","flight":"AC0855","msgno":"D74M","text":"#DFB37 13 12 12 131334\r\n002211  0  01001000045474532 13 12 12 131332\r\n002211  0  01001000045314529 13 12 12 131331"}
{"timestamp":1518619753.1174209,"station_id":"Pi3","channel":4,"freq":136.975,"icao":10807330,"mode":"2","label":"_d","block_id":"2","ack":"K","tail":"N415QS","flight":"GS415Q","msgno":"M60A"}
{"timestamp":1518619755.657136,"station_id":"Pi3","channel":4,"freq":136.975,"icao":4661107,"mode":"2","label":"H1","block_id":"2","ack":"!","tail":"HA-LXR","flight":"W609AY","msgno":"D02A","text"::"#DFB37 13 12 12 131334\r\n002211  0  01001000045474532 13 12 12 131332\r\n002211  0  01001000045314529 13 12 12 131331"}

The W609AY H1 message has been replaced with the original AC0855 '#DFB37 13 12 12 1313...' message and the json format has been corrupted to show "text"::"#DFB37 13 12 1 . It's now got 2 colons after the text token.

I can supply more examples if required.
I haven't checked yet if this also applies to acarsdec.
Regards
Stuart