Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

  • Congratulations strongm on being selected by the Tek-Tips community for having the most helpful posts in the forums last week. Way to Go!

Decoding DD tape image of NIM 4.1 calls

Status
Not open for further replies.

ffulvio

Systems Engineer
Mar 19, 2019
1
0
0
IT
Hi all,
We had a problem with the recovery of some old recordings recorded on tspe, the problem was that the number of taoes is greater than the number of records in the NMI database where phone calls are recorded and therefore some records of the db have been overwritten.

So we have extracted a raw data file from a magnetic tape using the dd command
after the first block we see
BSRV Element Header and other data,s we e have converted hexdump in 32 bit unsigned integer (U32) with byte order Little-endian, and we can see the Logger' number, the channel' number and the start and end of one call. I attache the image.

We have do for test una tape whit one recorded call, we have extracted only the data file and after severals attemps we have decoded whit with the RAW to G729 format.
I have tryed whit
cat filedump | /home/g72x/decode-g72x -64 -l -R | sox -r 8000 -b 16 -c 1 -e unsigned-integer -t raw - -t wav filedump.wav but whit no results,

with VA_g729_decoder on Windows and and ffmpeg -i option on ubuntu machine whi have returned the same result.

I have opened the wav file decoded whit Audacity whit import raw otion and whit opening it with 8000 Hz frequency, Unsigned 8 Bit PCM and 1 Mono channel i see something close to reality

The problem is that when I listen, I hear the recorded voice well for 3 seconds and then I feel like the speed increases, then another 3 seconds of voice and after another noise

The question is: how do I extract the phone calls from the raw dump by separating the audio from the metadata and having the audio sorted? Is there any different recovery mode or some ad hoc decoder?
How are stored in magnetic tape the data? When i see BSRV Element are the Header of One single recorded call are stored in g729 format or are one NMF file?

Thanks in advance!!!!
fulvio


 
 https://files.engineering.com/getfile.aspx?folder=337bf3e0-d19c-4d40-bbc3-9f7036538cb6&file=decoded.JPG
I'd recommend talking to these guys:
[URL unfurl="true"]http://www.electricalscience.com/voice-logger/[/url]
I used them in the past to decode old NICE and MERCOM logger recordings. They do a great job and for the headaches they save you, it's worth every penny!

LoPath
Maintain HiPath 4000 V5 & V6, OpenScape Xpert V4 & V6, OpenScape Xpressions V7, OpenScape Contact Center V8, OpenScape Voice V9
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor

Back
Top