All posts by js
Below are all of js's postings, with the most recent are at the bottom of the page.
I think I've found the answer to a question I asked on here years ago.
I was puzzled by the different bitrates of BBC B and COM7/COM8.
At that time, the BBC B bitrate was 40.215 Mbps while the COM7/COM8 bitrates were 40.200 Mbps, yet both were said to be using the same T2 parameters.
I could find a T2 parameter set with a match of 40,214,645 bps for BBC B but nothing matched COM7/COM8.
Recently, the Winter Hill BBC B bitrate changed to 40.209 Mbps.
Strangely, the BBC B off Haslingden, which has parent transmitter Winter Hill, still had a bitrate of 40.215 Mbps.
I determined to find the reason why.
Now, Haslingden comes and goes with the wind, but a couple of weeks ago, I was able to record simultaneously, the full transport streams off Winter Hill and Haslingden without error.
The idea was to match them packet for packet.
I thought, that's easy, just find PCRs with the same time value.
I found that the PCRs were slightly different but I was able to find the same packets in each file.
I discovered the only difference, apart from the PCR values, was the number - and type* - of Null Packets.
The PCR values had to be different precisely to account for the different number of Null Packets.
So, it appears, the number of Null Packets explains these differences in measured bitrate.
Now, Null Packets are used to maintain a constant bitrate for the transport stream; if the input data to the multiplexer falls below the target bitrate then Null Packets are inserted as required.
So there it is. Someone at Arqiva had entered the round number 40.200 as the target bitrate for COM7/COM8, and someone else had entered the exact theoretical bitrate as the target bitrate for BBC B.
It was pretty thick of me not to realise that the measured bitrate of a transport stream is determined by what might be an essentially arbitrary value in the multiplexer configuration.
*The Null Packets off the Haslingden BBC B have headers 47 1F FF 10
*The Null Packets off the Winter Hill BBC B have headers 47 1F FF 1F
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ASTRA/BSkyB Diffs:
Smithsonian LCN changed from 195 to 160.
Sky News, Pick and Pick+1 changed transponder, moving from 12207V to 12071H:
Food Network (ROI) was placed on BSkyB 140 in region 50 - ROI:
Comparing files List ASTRA 06-03-2020 18 01.txt and List ASTRA 10-03-2020 18 01.txt
************************ CHANGED ************************
SERVICE NAME TYPE EPGID SID TSID ONID FREQ.P ENC EIT PROVIDER BOUQUETS LCN
Renamed, EPGID Change, Bouquet Change, LCN Change
2908 1 0000 2908 2035 2 12383H 0 1 BSkyB 000000000000000
Food Network 1 5617 2908 2035 2 12383H 0 1 BSkyB 000010001000100 140
LCN Change
Smithsonian 1 1089 52126 2108 2 11265V 0 1 BSkyB 111111111111111 195
Smithsonian 1 1089 52126 2108 2 11265V 0 1 BSkyB 111111111111111 160
Renamed, EPGID Change, Bouquet Change, LCN Change
5832 1 1202 5832 2019 2 12071H 0 1 BSkyB 000000000000010 1024
Pick 1 1832 5832 2019 2 12071H 0 1 BSkyB 111111111111111 152, 159
Renamed, EPGID Change, Bouquet Change, LCN Change
Sky News 1 1404 4704 2026 2 12207V 0 1 BSkyB 111111111111111 501, 875
6404 1 0000 4704 2026 2 12207V 0 1 BSkyB 000000000000000
Service ID Change, Transponder Move
Sky News 1 1404 4704 2026 2 12207V 0 1 BSkyB 111111111111111 501, 875
Sky News 1 1404 6404 2019 2 12071H 0 1 BSkyB 111111111111111 501, 875
Renamed, EPGID Change, Bouquet Change, LCN Change
6404 1 1449 6404 2019 2 12071H 0 1 BSkyB 000000000000010 1026
Sky News 1 1404 6404 2019 2 12071H 0 1 BSkyB 111111111111111 501, 875
Renamed, EPGID Change, Bouquet Change, LCN Change
5836 1 1453 5836 2019 2 12071H 0 1 BSkyB 000000000000010 1028
Pick+1 1 1836 5836 2019 2 12071H 0 1 BSkyB 111111111111111 252
Service ID Change, Transponder Move
Pick 1 1832 4751 2026 2 12207V 0 1 BSkyB 111111111111111 152, 159
Pick 1 1832 5832 2019 2 12071H 0 1 BSkyB 111111111111111 152, 159
Service ID Change, Transponder Move
Pick+1 1 1836 5107 2026 2 12207V 0 1 BSkyB 111111111111111 252
Pick+1 1 1836 5836 2019 2 12071H 0 1 BSkyB 111111111111111 252
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Freesat Diffs:
Live 360 launched on Freesat 176:
Comparing files List Freesat 09-03-2020 18 01.txt and List Freesat 10-03-2020 11 01.txt
************************ CHANGED ************************
SERVICE NAME TYPE EPGID SID TSID ONID FREQ.P ENC EIT PROVIDER BOUQUETS LCN
Bouquet Change
Live 360 1 13002 55180 2095 2 11553H 0 1 Freesat 1EEE1EEE1EEE 176
Live 360 1 13002 55180 2095 2 11553H 0 1 Freesat 111111111111 176
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Ken W: You could use Wake-on-LAN and Remote Desktop Connection if you have a machine with you.
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Bad Characters Update
It's interesting to look at these events on the Freeview site:
TV Guide | Freeview
When I looked on there a few weeks ago, they were displaying the correct characters. They now seem to be using the same corrupt data they transmit.
For example, take error event #327 below:
This is what's transmitted:
******************
Al Jazeera Eng, Fri 13 Mar 20:00 - 21:00: title = "The Coming War On China", description = "Journalist John Pilger, reveals what the news doesn't {--} that the world's greatest military power, the U.S. may well be on the road to war with China."
******************
Freeview site:
******************
The Coming War On China
13 Mar 2020 - 8:00pm - 9:00pm
Download our Freeview mobile app
Summary
Journalist John Pilger, reveals what the news doesn't that the world's greatest military power, the U.S. may well be on the road to war with China.
******************
Note how ungrammatical that is without the --
A shortened error report follows:
Invalid Character Codes in the EIT off North West multiplex BBC A. Date: 2020/03/11 02:31:50
It has become apparent through observation that invalid bytes in the Freeview EIT text strings are the low-order bytes of the Unicode General Punctuation Block:
Of course only bytes less than 0x20 qualify as invalid codes in the context of EIT text strings.
Since about April 2018, the following invalid codes have been found in the Freeview EIT text items:
0x01, substitute: {0x01} -> Unicode Character: "EM QUAD" (U + 2001)
0x08, substitute: { } -> Unicode Character: "PUNCTUATION SPACE" (U + 2008)
0x0B, substitute: {} -> Unicode Character: "ZERO WIDTH SPACE" (U + 200B)
0x10, substitute: {-} -> Unicode Character: "HYPHEN" (U + 2010)
0x13, substitute: {--} -> Unicode Character: "EN DASH" (U + 2013)
0x14, substitute: {---} -> Unicode Character: "EM DASH" (U + 2014)
0x18, substitute: {L'} -> Unicode Character: "LEFT SINGLE QUOTATION MARK" (U + 2018)
0x19, substitute: {R'} -> Unicode Character: "RIGHT SINGLE QUOTATION MARK" (U + 2019)
0x1C, substitute: {L''} -> Unicode Character: "LEFT DOUBLE QUOTATION MARK" (U + 201C)
0x1D, substitute: {R''} -> Unicode Character: "RIGHT DOUBLE QUOTATION MARK" (U + 201D)
There are 1235 invalid codes in the current EIT:
invalid code, count, percentage
0x13, 4, 0.32%
0x18, 25, 2.02%
0x19, 1144, 92.63%
0x1C, 31, 2.51%
0x1D, 31, 2.51%
There are 942 events with invalid codes in the current EIT.
The Culprits:
Format:
service_name, number of events containing errors
BBC World Sv., 6
BBC Radio 4, 1
BBC World Sv., 6
BBC Radio 4, 1
Yaaas!, 17
Blaze, 22
ADULT Studio 66, 32
Planet Knowledge, 24
Sports Channel Network, 112
Ketchup TV, 11
RNIB Connect, 3
Food Network, 1
Sony Movies, 21
POP, 69
Al Jazeera Eng, 4
PBS America, 4
Sony Channel +1, 24
POP Max, 126
Tiny Pop, 85
Sony Movies +1, 3
Sony Channel, 28
Sony Movies Classic, 2
That's TV, 48
Tiny Pop, 85
Sony Movies +1, 3
Sony Channel, 28
Sony Movies Classic, 2
That's TV, 48
Tiny Pop, 85
Sony Movies +1, 3
Sony Channel, 28
Sony Movies Classic, 2
PBS America +1, 8
Events with invalid codes in the eight-day EIT off multiplex BBC A at 2020/03/11 02:31:50:
#1: BBC World Sv., Wed 11 Mar 11:32 - 12:00: title = "13 Minutes to the Moon", description = "1/6. {L''}Houston, we've had a problem.{R''} To ignite catastrophe would take just the flick of a single switch. Why Nasa's third bid to land on the Moon was flawed from the start.", description error bytes: 0x1C, 0x1D
...
#4: BBC World Sv., Tue 17 Mar 04:32 - 05:00: title = "In the Studio", description = "Nicknamed the {L''}first lady of graffiti{R''}, Ecuadorian-American artist Lady Pink talks murals, music and money.", description error bytes: 0x1C, 0x1D
...
#7: BBC Radio 4, Sun 15 Mar 08:10 - 08:48: title = "Sunday Worship", description = "From St Patrick's Church, Coleraine, on the Lenten theme, {L''}Care for God's Creation{R''}.", description error bytes: 0x1C, 0x1D
...
#15: Yaaas!, Wed 11 Mar 00:30 - 01:00: title = "Wallace and Gromit's...", description = "... Cracking Contrapitions. From the Soccamatic to the 535 Crackervac, Wallace{R'}s inventions are truly imaginative if not always the most efficient!", description error byte: 0x19
...
#327: Al Jazeera Eng, Fri 13 Mar 20:00 - 21:00: title = "The Coming War On China", description = "Journalist John Pilger, reveals what the news doesn't {--} that the world's greatest military power, the U.S. may well be on the road to war with China.", description error byte: 0x13
...
#942: PBS America +1, Wed 18 Mar 15:20 - 15:55: title = "Steven Raichlen's...", description = "...Project Fire: Raichlen{R'}s Rules: In this episode, Steven looks at fundamental techniques that he has employed over the years. (Part 12 of 12)", Huffman coded, description error byte: 0x19
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ASTRA/BSkyB Diffs:
Smithsonian HD Transponder Move from 11171H to 11509V:
Comparing files List ASTRA 11-03-2020 18 01.txt and List ASTRA 12-03-2020 18 00.txt
************************ CHANGED ************************
SERVICE NAME TYPE EPGID SID TSID ONID FREQ.P ENC EIT PROVIDER BOUQUETS LCN
Service ID Change
55271 25 1196 55271 2092 2 11509V 0 1 BSkyB 000000000000010 1014
55271 25 1196 51110 2092 2 11509V 0 1 BSkyB 000000000000010 1014
Renamed, EPGID Change, Bouquet Change, LCN Change
55271 25 1196 55271 2092 2 11509V 0 1 BSkyB 000000000000010 1014
Smithsonian HD 25 5135 55271 2092 2 11509V 0 1 BSkyB 111111111111111 889
Service ID Change, Transponder Move
Smithsonian HD 25 5135 51110 2071 2 11171H 0 1 BSkyB 111111111111111 889
Smithsonian HD 25 5135 55271 2092 2 11509V 0 1 BSkyB 111111111111111 889
Video Bitrate (Mbps) sampled at 36 <= dPCR <= 40 ms intervals over 17 seconds for 11170.75 H 22000 5/6 DVB-S QPSK (13/03/2020 09:41:55)
maximum | minimum | average | service_name
01.723 | 01.445 | 01.559 | A1TV
03.331 | 03.090 | 03.187 | Racing TV [ENC]
02.007 | 01.100 | 01.486 | TCM Movies [ENC]
03.028 | 01.017 | 01.850 | Cartoonito [ENC]
03.471 | 01.224 | 01.799 | TCM Movies+1 [ENC]
03.799 | 01.467 | 02.403 | Boomerang [ENC]
03.367 | 01.254 | 01.913 | Boomerang+1 [ENC]
02.770 | 01.012 | 01.886 | Cartoon Netwrk [ENC]
04.547 | 01.793 | 03.093 | CN+1 [ENC]
11.345 | 09.561 | 10.418 | Null Packets
05.217 | 03.196 | 04.197 | All Other Streams
33.791 | 33.791 | 33.791 | TS Bitrate
Video Bitrate (Mbps) sampled at 31 <= dPCR <= 65 ms intervals over 16 seconds for 11508.50 V 23000 2/3 DVB-S2 8PSK (13/03/2020 09:42:40)
maximum | minimum | average | service_name
09.788 | 09.571 | 09.681 | eir Sport 1 HD (55276) [ENC]/eir Sport 1 HD (55275) [ENC]
08.689 | 08.527 | 08.600 | Smithsonian HD
11.947 | 11.055 | 11.630 | Racing TV HD [ENC]
08.602 | 07.363 | 08.433 | TRT World HD
04.923 | 01.588 | 02.967 | Null Packets
04.396 | 02.222 | 03.208 | All Other Streams
44.521 | 44.520 | 44.521 | TS Bitrate
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Chris.SE: I had the data on this so thought I'd try to see what's going on.
In the midnight and one am slots, they have series 16 running and in the 10pm and 11pm slots, series 17 running.
Series 16 ends on Fri 13 Mar 00:55 so the next programme in the slot should be S17 Ep 1, which it is, but with the crid for series 7.
Then, on Saturday, they change the time slots to 9pm and 10pm ... at which point, I abandon any further attempt at logical analysis.
It must be very confusing for viewers.
They use crids R7I2R for series 6 and R7I2S for series 7, rather than for the slots the viewer is following.
Presumably, a PVR record would record every episode with the same crid.
A dump from my EIT program follows:
EIT date: Wed 11 Mar 02:31
service_name = "5 USA"
programme = "Law & Order: Special Victims Unit"
{
crid = "/R7I2R", series, dates:
Wed 11 Mar 00:55, S16 Ep 19
Wed 11 Mar 23:55, S16 Ep 20
Thu 12 Mar 00:50, S16 Ep 21
Thu 12 Mar 23:55, S16 Ep 22
Fri 13 Mar 00:55, S16 Ep 23
crid = "/R7I2S", series, dates:
Wed 11 Mar 22:00, S17 Ep 9
Wed 11 Mar 22:55, S17 Ep 10
Thu 12 Mar 22:00, S17 Ep 11
Thu 12 Mar 22:55, S17 Ep 12
Fri 13 Mar 22:00, S17 Ep 13
Fri 13 Mar 23:00, S17 Ep 14
Fri 13 Mar 23:55, S17 Ep 1
Sat 14 Mar 00:55, S17 Ep 2
Sat 14 Mar 21:00, S17 Ep 15
Sat 14 Mar 22:00, S17 Ep 16
Sat 14 Mar 23:00, S17 Ep 3
Sat 14 Mar 23:55, S17 Ep 4
Sun 15 Mar 22:00, S17 Ep 17
Sun 15 Mar 22:55, S17 Ep 5
Sun 15 Mar 23:55, S17 Ep 6
Mon 16 Mar 22:00, S17 Ep 18
Mon 16 Mar 23:00, S17 Ep 19
Mon 16 Mar 23:55, S17 Ep 7
Tue 17 Mar 00:55, S17 Ep 8
Tue 17 Mar 22:00, S17 Ep 20
Tue 17 Mar 22:55, S17 Ep 21
Tue 17 Mar 23:55, S17 Ep 9
Wed 18 Mar 00:50, S17 Ep 10
Wed 18 Mar 22:00, S17 Ep 22
Wed 18 Mar 22:55, S17 Ep 23
Wed 18 Mar 23:55, S17 Ep 11
}
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Chris.SE: I haven't seen that. Can you give a specific example?
Quote: "On my set I can get programme info which often states the series and episode, whereas the EPG does not often give the same information."
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Friday 6 March 2020 7:24PM
ASTRA/BSkyB Diffs:
Pick was put on BSkyB 159 in region 34 - Channel Islands.
Entries for some defunct services were DELETED:
Comparing files List ASTRA 05-03-2020 18 01.txt and List ASTRA 06-03-2020 18 01.txt
************************ CHANGED ************************
SERVICE NAME TYPE EPGID SID TSID ONID FREQ.P ENC EIT PROVIDER BOUQUETS LCN
LCN Change
Pick 1 1832 4751 2026 2 12207V 0 1 BSkyB 111111111111111 152
Pick 1 1832 4751 2026 2 12207V 0 1 BSkyB 111111111111111 152, 159
************************ DELETED ************************
SERVICE NAME TYPE EPGID SID TSID ONID FREQ.P ENC EIT PROVIDER BOUQUETS LCN
5Spike+1 1 0000 7731 2057 2 10964H 0 1 BSkyB 000000000000000
V Channel 1 0000 50425 2067 2 11112H 0 1 BSkyB 000000000000000
Bible TV 1 0000 54227 2089 2 11464H 0 1 BSkyB 000000000000000
Heart TV 1 0000 8888 2095 2 11553H 0 1 BSkyB 000000000000000
CAPITAL TV 1 0000 55112 2095 2 11553H 0 1 BSkyB 000000000000000
Retail TV 1 0000 5005 2096 2 11568V 0 1 BSkyB 000000000000000
DirtyTalk 1 0000 54053 2102 2 11656V 0 1 BSkyB 000000000000000
BoXmas 1 0000 7210 2107 2 11265H 0 1 BSkyB 000000000000000