dtt trial - no picture from mpeg4

Valentia · 26-04-2007 12:39am #1

I just set up the new box and all is working well except C25, the mpeg4 feed is giving me sound and no picture. I am using a Hyundi and HDMI connection. Is there something I should do or are is the box and TV incompatible?

DigiDec · 26-04-2007 8:36am

Are you part of the dtt trial?

watty · 26-04-2007 3:18pm

The MPEG4 is encrypted. Also you need an MPEG4 capabile box. Any bought retail locally or UK aren't

Valentia · 26-04-2007 4:12pm

I'm part of the trial so the box should work. As I said all the other channels are ok. ?? The Hyundi is the TV in case there was confusion.

watty · 26-04-2007 9:56pm

Is your viewing card in the right way up and right way round?

Of course sometimes they simply don't transmit properly!

Mossy Monk · 26-04-2007 9:59pm

Valentia wrote:

I'm part of the trial so the box should work. As I said all the other channels are ok. ?? The Hyundi is the TV in case there was confusion.

Perhaps it is like this for everyone else on the trial?

Valentia · 26-04-2007 10:35pm

Thanks lads. I think the card must be in right or else I wouldn't be getting the other channels? Yeah, I wonder if is it the same for everybody else. Sound (Sky News) but no picture. Anyone else on the trial getting this?

watty · 27-04-2007 7:44am

Some of the channels (RTE, TG4, TV3) work with no card.

Valentia · 27-04-2007 3:03pm

I know

I have them all (encrypted too) except C25 has sound and no picture., the mpeg 4 test channel. As you say it may be the same for everyone. All I was wondering was if there is any technical reason, provided the decoder and receiver are working properly, why it was not working.

I have gone through the DTT stickies but they are so off topic I gave up.

DMC · 27-04-2007 3:59pm

Hi Valentia, its a bit of a maze here, as there are not many trailists posting here. I've no way of knowing if the MPEG4 channels is working, but are you getting sound on it when not connected to a HD source? iirc, Sky News sound was on it.

Valentia · 27-04-2007 4:23pm

DMC wrote:

Hi Valentia, its a bit of a maze here, as there are not many trailists posting here. I've no way of knowing if the MPEG4 channels is working, but are you getting sound on it when not connected to a HD source? iirc, Sky News sound was on it.

Thanks DMC. I only have it connected through the HDMI. I'll try a scart over the weekend. As it is I'm getting the sound from Sky news and no picure. The TV is HD ready but I was thinking that maybe for some reason the TV is the cause as I have never tried HD with it before. If only my son would get that PS 3 he has been talking about I might be able to try a Blu-Ray DVD thingy on it;)

watty · 27-04-2007 5:37pm

No HD on SCART ever. May or may not give a downscaled picture.

If the TV is "HD Ready" and you have HDMI cable, then it is more likely there is no picture than it "broken" at your end.

I havn't seen any BD titles yet in my local Tesco or Heatons

Valentia · 27-04-2007 6:05pm

watty wrote:

I havn't seen any BD titles yet in my local Tesco or Heatons

I believe Xtravision are renting them.

watty · 27-04-2007 10:47pm

I don't rent.
My motto is that if it is worth watching once, then I'll watch it again. I got 4 Bing Crosbys on one package for 8.50 last time. "Pennies from Heaven" has an impossibly young Louis Armstrong and Bing Crosby.

It's been a while since I checked Xtravision's previously viewed stock as often the same thing, new, was in Heitons at same or cheaper price!

Valentia · 28-04-2007 3:47am

Yep, but I was only thinking of doing it for experimental purposes. Forking out on a BR now seems like madness. Betamax II could appear and blow it away!

maxg · 28-04-2007 8:27am

Valentia wrote:

Thanks DMC. I only have it connected through the HDMI. I'll try a scart over the weekend. As it is I'm getting the sound from Sky news and no picure. The TV is HD ready but I was thinking that maybe for some reason the TV is the cause as I have never tried HD with it before. If only my son would get that PS 3 he has been talking about I might be able to try a Blu-Ray DVD thingy on it;)

If the copy protection bit is not set you get a downscaled picture via scart for a HDTV channel from your humax box.
If you get a picture via scart there is a problem with the HDMI compatibility.
For instance such compatibility problems between Humax HDCI 1000 and older HDTV ready tellies are pretty common at the continent.
Maybe there is a software update available for your TV.
Ask your TV dealer if you cannot solve your problem by yourself.

Zaphod · 28-04-2007 9:43am

Is the MPEG4 stream definitely encrypted - does the sound disappear when you pull out the card?

And I thought they were testing SD over MPEG4 and not HD?

watty · 28-04-2007 12:11pm

I've received plenty encrypted channels with only video stream, encrypted, sound clear.

watty · 28-04-2007 12:15pm

Zaphod wrote:

Is the MPEG4 stream definitely encrypted - does the sound disappear when you pull out the card?

And I thought they were testing SD over MPEG4 and not HD?

They will "test" both, as there is no real plan and they can.

In reality the enn article is daft. MPEG4 is not "next generation" it's out there now.

The BBC HD is only a trial and not a real service due to delay in the whole Freesat thing due to changeover from Governors to Trust

Valentia · 28-04-2007 2:14pm

Sound goes when the card is removed.

I've tried a scart. Still the same. Sound & no picture. The problem is probably at the transmission end or the Humax box can't decode mpeg4. It is marked as mpeg4 compatoble though.

Thanks for the help.

maxg · 28-04-2007 3:51pm

Normally the audio stream is also encoded in mpeg4. It looks like a problem at the transmission end with the picture.

watty · 28-04-2007 4:44pm

Encryption is a separate issue to MPEG.
MPEG4 is a video Codec and TS definition. There is no such thing as MPEG4 audio.

You can have MPEG4 video (encrypted or clear) or MPEG2 Video and Audio (encrypted or clear) in a variety of codecs in a MPEG2 TS or MPEG4 TS.

You can have multiple different audio streams.

Each thing: Interactive, video, audio, surround, Teletext and or EPG is a separate stream. Each stream has to be separately encrypted (if desired).

watty · 28-04-2007 4:49pm

Valentia wrote:

Sound goes when the card is removed.

I've tried a scart. Still the same. Sound & no picture. The problem is probably at the transmission end or the Humax box can't decode mpeg4. It is marked as mpeg4 compatoble though.

Thanks for the help.

The Humax definitely does MPEG4 for SD and HD.

Zaphod · 29-04-2007 9:45am

watty wrote:

I've received plenty encrypted channels with only video stream, encrypted, sound clear.

Yes, for PowerVu and Cryptoworks which leave the audio unencrypted but not Conax as #20 confirms.

Anyone with a compatible PCI or USB DVB-T tuner could use a copy of TSReader to see if any video data is being transmitted and what the bit rate is like.

maxg · 29-04-2007 3:41pm

watty wrote:

Encryption is a separate issue to MPEG.
MPEG4 is a video Codec and TS definition. There is no such thing as MPEG4 audio.

You can have MPEG4 video (encrypted or clear) or MPEG2 Video and Audio (encrypted or clear) in a variety of codecs in a MPEG2 TS or MPEG4 TS.

You can have multiple different audio streams.

Each thing: Interactive, video, audio, surround, Teletext and or EPG is a separate stream. Each stream has to be separately encrypted (if desired).

List of audio mpeg formats:

MPEG-1 Audio Layer 1
MPEG-1 Audio Layer 2
MPEG-1 Audio Layer 3
MPEG-2 BC Multichannel
MPEG-2 AAC
MPEG-4 AAC
MPEG-4 ALS

For HDTV channels mpeg1 audio layer2 with ac3 or mpeg4 aac-he is in use.
Which format is in use for the irish mpeg4 trial you have to check by yourself.

dtt trial - no picture from mpeg4

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