: HTPC Tools For Ottawa OTA Analysis


roger1818
2011-08-23, 08:35 AM
ashtonp, In what way were the locals more reliable with the CM7777 vs. the Kitz200 (you only talk about local signal levels without an amp).

Also, how did you read the "max signal level of 0xFA" for Global with the 950Q? Is this a feature in MythTV or did you use some other program?

ashtonp
2011-08-23, 12:19 PM
Roger, for the local HC digitals except OMNI2, the reliability didn't really improve (they were already pretty solid), but I did see an improvement in the reported signal levels). The local HC analogues were visibly improved, but I don't have a way of measuring their levels.

To read the 950q signal levels, I use "scan" to create a channels list:
scan us-ATSC-center-frequencies-8VSB -o zap -a 0 | tee ~/channels_herbertscorners_2011Aug23.conf
then "azap":
azap -c ~scales/channels_herbertscorners_2011Aug23.conf -r -a 0 "CITYHD"
Unfortunately, the reported values are not normalized, so you cannot compare results from a 950Q vs a HVR1950, for example.
(Off topic, but perhaps useful for Linux users trying to optimize Global.)

flavoie
2011-08-23, 01:03 PM
Mike, would you mind trying tsreader (i think Lite is free) and posting what it outputs for the Global Ottawa channel ? It may help figuring out where there's a potential problem in the Psip info. I recall Peter Near spotting unmatched tsid in different sections making wmc fail certain channels, for example. I wish I could locate his past blog posts about it.

OTAJuncqui
2011-08-23, 01:29 PM
here ya go:
http://www.flickr.com/photos/6603455...n/photostream/ (http://www.flickr.com/photos/66034556@N05/6073395207/in/photostream/)

TSReader screen cap of Global Ch 6

(pls excuse sloppy double post)

flavoie
2011-08-23, 01:33 PM
cool ! are you able to convert (or export) to HTML for a "fuller" info dump ?

flavoie
2011-08-23, 02:21 PM
Let's see if I my own post works. OTAJuncqui has trouble posting the text info here, THANKS OTAJuncqui for the fuller info dump !!!

I was reading a bit on it vs a similar issue I had seen reported before. We could have have the same problem here. The Transport Stream ID (0x0001) does not match the Terrestrial Virtual Channel Table TSID (0x432b).

*Program Association Table*

PAT Version Number: 5
Transport Stream ID: 1 (0x0001)

PMT PID 48 (0x0030) - Program 1 CIII-HD

*Program Map Table(s)*

Program Number: 1 CIII-HD
PCR PID: 0x0031

Stream Type: 0x02 MPEG-2 Video PID 49 (0x0031)
MPEG Video: Bitrate 24.000 Mbps Resolution 1920 x 1080i
MPEG Video: Framerate 29.97 fps Aspect Ratio 16:9 Chroma Format 4:2:0

Stream Type: 0x81 AC-3 Audio PID 52 (0x0034)
AC3: Bitrate 384 Kbps Sample Rate 48 KHz
AC3: Mode complete main Coding 3/2 5 L, C, R, SL, SR
Descriptor: ISO639 Language Descriptor
Language: eng
Audio type: undefined
Descriptor: ATSC AC-3 audio Descriptor
ATSC AC3 Descriptor

Stream Type: 0x81 AC-3 Audio PID 53 (0x0035)
AC3: Bitrate 192 Kbps Sample Rate 48 KHz
AC3: Mode complete main Coding 2/0 L, R
Descriptor: ISO639 Language Descriptor
Language: eng
Audio type: undefined
Descriptor: ATSC AC-3 audio Descriptor
ATSC AC3 Descriptor

*Terrestrial Virtual Channel Table*

Channel 1
Service Name: CIII-HD
TSID: 17195 (0x432b)
Channel Number: 6.1
Carrier Frequency: 0
Modulation Mode: ATSC (8 VSB)
Source ID: 1
Descriptor: ATSC Service Location Descriptor
Service Location Descriptor:
PCR PID 0x0031
Stream Type 0x02 (MPEG-2 Video) ESPID = 0x0031 Language =
Stream Type 0x81 (AC-3 Audio) ESPID = 0x0034 Language = eng
Stream Type 0x81 (AC-3 Audio) ESPID = 0x0035 Language = eng

*Event Information Table*

*MPEG-2 Statistics*

*Table**Sections Processed**CRC Errors*PAT1.4k0CAT00PMT20ETT1790PSIP9650EIT2980
Continuity errors: 1
TEI errors: 1
Sync Losses: 0
Calculated multiplex rate: 19392862 bps

*General Information*

Source: ATSC BDA Source
Tuner: Channel 6 (85 Mhz)
Signal: Locked: 79% ( 0.036 dBm)
Network Type: ATSC
Run Time: 000:01:26

*PID Usage Chart*

0x0000 (0.13% ~ 0.03 Mbps)0x0000 MPEG-2 Program Assocation Table0x0030 (0.13% ~ 0.02 Mbps)0x0030 MPEG-2 PMT for program 10x0031 (81.07% - 15.73 Mbps) *1/00x0031 MPEG-2 Video for program 10x0034 (2.04% ~ 0.39 Mbps)0x0034 AC-3 Audio for program 10x0035 (1.02% ~ 0.20 Mbps)0x0035 AC-3 Audio for program 10x0041 (11.75% - 2.28 Mbps)0x0041 Unknown usage0x0044 (1.02% ~ 0.20 Mbps)0x0044 Unknown usage0x0045 (1.02% ~ 0.20 Mbps)0x0045 Unknown usage0x0071 (0.00% ~ 0.00 Mbps) *0/10x0071 Unknown usage0x1d00 (0.02% ~ 0.00 Mbps)0x1d00 ATSC EIT-00x1d01 (0.01% ~ 0.00 Mbps)0x1d01 ATSC EIT-10x1d02 (0.00% ~ 0.00 Mbps)0x1d02 ATSC EIT-20x1d03 (0.00% ~ 0.00 Mbps)0x1d03 ATSC EIT-30x1e00 (0.01% ~ 0.00 Mbps)0x1e00 ATSC Event ETT-00x1e01 (0.00% ~ 0.00 Mbps)0x1e01 ATSC Event ETT-10x1e02 (0.00% ~ 0.00 Mbps)0x1e02 ATSC Event ETT-20x1e03 (0.00% ~ 0.00 Mbps)0x1e03 ATSC Event ETT-30x1ffb (0.09% ~ 0.02 Mbps)0x1ffb ATSC Base PID (TVCT, MGT, RT, STT)0x1fff (1.70% ~ 0.33 Mbps)0x1fff MPEG-2 NULL Packet

vejostde
2011-08-25, 11:40 PM
There are some useful linux tools available in the downloads section of pchdtv.com. Not all the tools work with all atsc cards, but it works with cards that will report signal and snr levels. It works on my Dvico Fusion HDTV5 RT Gold tuner card, and my Hauppauge HVR-950q. It does not work with the Air2PC card or the HVR-950 (with the older chipset).

I found dtvnsr useful to aim my antenna to get Global on channel 6 in Ottawa.

/dvb-atsc-tools-1.0.7$ ./dtvsnr -dvb 3 6
using '/dev/dvb/adapter3/frontend0' and '/dev/dvb/adapter3/demux0'
tuning to 85000000 Hz
video pid 0x0021, audio pid 0x0024
dtvsnr ver 1.0.7 - by Jack Kelliher (c) 2006-2007
channel = 6 freq = 85000000Hz
dB -10 0 10 20 30 40
SNR: | | | | | |
SNR: 017 ============================


dtvsignal is similar, getatsc will dump the data stream, and atscpackets counts the packets received for each PID.
There's also a scan tool, dtvscan.

vejostde
2011-08-25, 11:57 PM
This is a simple tool that tries to get current program info from a specified frequency and subchannel. It doesn't always work, and many stations don't send useful program info, but someone might find some use for it.

$ ./simpguide
incorrect usage. do ./simpguide <rf channel> <virtual subchannel>
$ ./simpguide 25 1
Current time: Thu Aug 25 23:53:04 2011

4.1 - Current program: Ha!ifax Comedy Festival
Running until Fri Aug 26 00:00:00 2011
Description: No description given.


I found it here. http://polypux.org/projects/dtv/