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Lip-Sync issue

/df said:
5Select is a DVB-T2 channel where I've seen it, which is more significant for this issue than the actual resolution, I think, though the actual audio compression standard in use may be relevant. But of course there's no DVB-T equivalent for comparison.
Click to expand...
5Select is indeed on the BBC B multiplex; and in all Nations and Regions.

Digitalbitrate reports it as 96 kbit/s AAC. So it will be transcoded to DD 2.0 in any Freeview HD receiver.
HD channels are all 128 kbit (stereo 2.0) or 320 kbit/s for 5.1 surround. (Plus a 48 kbit Narration (audio description) data channel that can be mixed in to the main audio).
5Select had a PID for audio description allocated, but with zero data recorded; so might sometimes carry AD?

I'll be really interested in what the TV speakers vs the ARC out to soundbar gives with the Humax on bitstream and am rather surprised the OP has not already tried that test.

As other -T2 users aren't all complaining, it's either not an issue for them or - perhaps - OP is especially sensitive to lip sync errors.

I wonder if anyone here has a .TS file recording from when the BBC transmitted the HD Test Card and Lip Sync Test that could be used by OP (and other -T2 users) as a known sample programme? {Not the You Tube re-encoded copies out there.}
Assuming it was ever broadcast on terrestrial TV !?? (I have some, brief, DSat recordings of them but they aren't HE-AAC of course and it may be something to do with that transmission method.)
 
/df said:
5Select is a DVB-T2 channel where I've seen it, which is more significant for this issue
Click to expand...
I sincerely doubt that the modulation has any effect whatsoever. By the time the box gets round to attempting to decode the streams, the demodulation stage is history. If there was a DVB-T stream of it then the data received would be the same, all other things being equal.
 
Rodders53 said:
wonder if anyone here has a .TS file recording from when the BBC transmitted the HD Test Card and Lip Sync Test
Click to expand...
I recorded some of it on the last day of BBC HD. Running ffprobe on it generates this:
Code: 
Input #0, mpegts, from 'This Is BBC HD_20130326_0120.ts':
  Duration: 00:07:33.59, start: 35136.152344, bitrate: 2899 kb/s
  Program 17472 
    Metadata:
      service_name    : BBC HD
      service_provider: 
    Stream #0:0[0x65]: Video: h264 (High) ([27][0][0][0] / 0x001B), yuv420p(tv, bt709, progressive), 1920x1080 [SAR 1:1 DAR 16:9], 25 fps, 25 tbr, 90k tbn, 50 tbc
    Stream #0:1[0x66](eng): Audio: aac_latm (LC) ([17][0][0][0] / 0x0011), 48000 Hz, 5.1, fltp
    Stream #0:2[0x6a](eng): Audio: aac_latm (HE-AACv2) ([17][0][0][0] / 0x0011), 48000 Hz, stereo, fltp (visual impaired) (descriptions) (dependent)
    Stream #0:3[0x69](eng): Subtitle: dvb_subtitle ([6][0][0][0] / 0x0006)
 
... By the time the box gets round to attempting to decode the streams, the demodulation stage is history. ..
Click to expand...

The significance wouldn't arise from the modulation/demodulation itself, but the associated media encoding/decoding which are systematically associated.
 
prpr said:
I sincerely doubt that the modulation has any effect whatsoever.
Click to expand...
My concern is that the "test data" should have surround sound.

Rodders53 said:
As other -T2 users aren't all complaining, it's either not an issue for them or - perhaps - OP is especially sensitive to lip sync errors.
Click to expand...
I think that has been ruled out, the OP's co-residents complain so it's not just one, and I watch a lot of snooker so yes I would notice, but on the other hand I don't use a soundbar or surround.

A lot of material isn't well synced at source, but that tends to be news inserts and such like.

Come to think of it, the erratic lip sync I used to experience at a friend's was using a soundbar.
 
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prpr said:
I recorded some of it on the last day of BBC HD
Click to expand...
Great. The .TS file of the BBC Lip Sync segment could, perhaps, be shared with the OP (and others, myself included) to eyeball measure sound - vision delays?
All we'd need to do is upload it to our -T2s (or other Freeview HD PVRS, where they permit) and play it {may need AV2HDR for -T2 to generate sidecar files correctly?}.

(I would need to relocate my -T2 from Kitchen to Lounge if I needed to invoke my AVR in the test, and install the correct AV2HDR.)

Then we can all compare apples with apples (well, apart from TV brand/models and/or AV systems attached via optical/arc) and the BBC Test Card A/V sync test was known to be accurate within a millisecond back in 2008,
via satellite ;). See

BBC - BBC Internet Blog: A Christmas Present from the HD Channel!

...those of you who work in the business know the phrase
www.bbc.co.uk www.bbc.co.uk

(MediaInfo gives similar analysis readouts of -T2 HD files.)

Black Hole said:
My concern is that the "test data" should have surround sound.
Click to expand...
Not important IMHO. The OP has complained about a talking heads programme which will have been a 2.0 DD transcode not 5.1 surround. Also the BBC Wales' Scrum V programme mentioned would not be a likely candidate for 5.1 (expensive) production?
The BBC test card, though, is in 5.1 throughout; so your desire will be satisfied if we can get that as a file as a -T2 recording.

I'd obviously missed the importance of this bit from earlier though...
Sargan said:
It's also set for Samsung Q-Symphony ... https://tinyurl.com/4rk9p7yp where 5 speakers on TV become the central Ch and Soundbar gives more immersive sound, ( and it does sound good)
I know PVR won't support these, but perhaps that all this extra processing of the Audio is giving me the Lip-Sync delay.
Click to expand...
Certainly take that Q Symphony setting off to see if things change with the -T2 lip sync, as well as trying the TV speakers alone. Although I doubt it will make any difference. I suspect some sort of hdmi auto-lip sync delay mis-communication between the -T2 and TV over hdmi, only significant when bit-steaming DD, is the issue here and I'm not sure if that can be disabled?
 
@Black Hole :RTFM: page 48

In Humax speak
"Multichannel" = bitstream = Dolby Digital, except for MPEG audio when it's PCM out
"Stereo" = all are PCM stereo

Two channels can count as multichannel if you want to really try and split hairs.
 
If you're going to give anyone a bollicking, you had better get your facts right. This is page 50:

1680117177171.png

It seems you do, but I don't know the audio channel when a StDef broadcast is DVB-T2 isn't MP2.
 
I made a test recording from 5Select (teleshopping) and the soundtrack is reported as AAC-LATM. However, the smoking gun is that when viewing 5Select with Multi-channel selected, the volume control becomes inoperative (my TV does not action the volume control information).
 
Black Hole said:
It seems you do, but I don't know the audio channel when a StDef broadcast is DVB-T2 isn't MP2.
Click to expand...
You do if you do a minimum of investigation (e.g. check digutalbitrate link) and/or read the FFFFFFF thread properly where i stated (bold now added)
Rodders53 said:
5Select is indeed on the BBC B multiplex; and in all Nations and Regions.

Digitalbitrate reports it as 96 kbit/s AAC. So it will be transcoded to DD 2.0 in any Freeview HD receiver.
Click to expand...
AAC is not MPEG. Freeview HD spec doesn't permit any other audio format, nor any other video codec

Lord help us!!!

Black Hole said:
I made a test recording from 5Select (teleshopping) and the soundtrack is reported as AAC-LATM. However, the smoking gun is that when viewing 5Select with Multi-channel selected, the volume control becomes inoperative (my TV does not action the volume control information).
Click to expand...
That'll be a foible of your TV decoding the transcoded DD (AAC) bitstream... possibly.

Perfectly normal for the -T2 (or Foxsat) volume control to do nothing as DD is output fixed level. Too expensive to have a DD encoder in the boxes to enable that.
 
Rodders53 said:
The .TS file of the BBC Lip Sync segment could, perhaps, be shared with the OP (and others, myself included) to eyeball measure sound - vision delays?
Click to expand...
https://dl.dropbox.com/s/pk4bvdnqd6yttyn/This Is BBC HD_20130326_0120.zip
All we'd need to do is upload it to our -T2s (or other Freeview HD PVRS, where they permit) and play it {may need AV2HDR for -T2 to generate sidecar files correctly?}.
Click to expand...
Sidecar files included (for the T2). (AV2HDRT2 is only for masochists. Why not use Sidecar?)
 
Rodders53 said:
I wonder if anyone here has a .TS file recording from when the BBC transmitted the HD Test Card and Lip Sync Test that could be used by OP
Click to expand...
I do. It was recorded on my foxsat hd but crucially before nowster's patch was applied. Don't know if decrypting is possible.
 
prpr said:
https://dl.dropbox.com/s/pk4bvdnqd6yttyn/This Is BBC HD_20130326_0120.zip

Sidecar files included (for the T2). (AV2HDRT2 is only for masochists. Why not use Sidecar?)
Click to expand...
Thanks for the file(s).
My -T2 is under-used, in the kitchen and touring caravan mainly so I'm not fully au fait with all the -T2 features sadly. 😢
One day, maybe?

sine24 said:
I do. It was recorded on my foxsat hd but crucially before nowster's patch was applied. Don't know if decrypting is possible.
Click to expand...
I have similar Foxsat-HDR recordings, unencrypted. You can't decrypt Foxsat recordings after the event.

But the -T2 and Foxsat recorded transport streams are a bit different (satellite vs freesat specs) and a Foxsat recording would not test the issue wrt HE-AAC transcoding that I suspect is the OP's TV/Soundbar issue.
I suspect a Foxsat recording of it might even play in sync off the -T2.
 
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