HDMI Advice appreciated.

[cumbriasteve]

Well my problem has been solved, perhaps not solved but identified.

It appears my TV supports mpeg2 but nothing beyond that, the videos are mpeg4.

Tried two other TV's and all works well, this proves the tablets software or the lead is not the issue.

So mate is giving me a box of tricks that will accept usb and outputs with various formats of which at least one of them will provide me a picture and sound he reckons.

That will allow me to watch what I have downloaded at least.

 

[Flapdisk]

Good to hear mate, for anyone else with similar problems you can buy these little media players like on here http://www.amazon.co.uk/s/ref=nb_sb...field-keywords=media player&sprefix=media,aps

Even a £20 one will do the job and the beauty of them is that they connect to your tv and will play just about any format of video you can throw at it, plust audio and pictures. They are usualy remote controlled so you can control it from your armchair, some have internal hard disks to store your files on , some need you to plug in an external usb or network drive, most will accept a usb stick.
I have been using one for years and couldn't be without it, the one I have will even play stuff that vlc player on the pc won't.
Oh! and most of them will upscale to HD

 

[Rocketman]

I'd love to find a video from a guy from the organisation who sets the HDMI standard, unfortunately I just can't find it in a search anymore.

It was absolutely damming over expensive cables and pointed out that many of the expensive cables had just as many problems as the a really cheap one.

If a company makes a cable to the correct standards there should be zero problems and zero reason to spend a penny more.

What's laughable is the reviews of expensive cables giving better picture.

 

[DanielW]

Hah! cables,how about this one....

Bought an in car video display monitor off ebay for the headrest on back of seat,problem is there was no cable to hook it up to the video.

display was £15 thought I'd got a bargain till I contacted Panasonic for the cable....jaw dropping moment....£85.....Oh thats all right I'll have two please.

Unbelievable,its their own brand of cable and specific connector ie you can't buy the connector as its not common.
Blow that D/L wiring diagram opened the display up and permantly soldered a cable to the internal socket rails.

 

[pedrobedro]

Good to hear mate, for anyone else with similar problems you can buy these little media players like on here http://www.amazon.co.uk/s/ref=nb_sb_noss_1?url=search-alias=aps&field-keywords=media player&sprefix=media,aps

We got a similar player from ebuyer, £17.99 and it plays DVD and you can plug a USB stick with divx or xvid and it will play them as well. You can get something like divx converter which will change the file format so it can be played on other devices as well.

 

[Flapdisk]

Hah! cables,how about this one....

Bought an in car video display monitor off ebay for the headrest on back of seat,problem is there was no cable to hook it up to the video.

display was £15 thought I'd got a bargain till I contacted Panasonic for the cable....jaw dropping moment....£85.....Oh thats all right I'll have two please.

Unbelievable,its their own brand of cable and specific connector ie you can't buy the connector as its not common.
Blow that D/L wiring diagram opened the display up and permantly soldered a cable to the internal socket rails.

That's the kind of dirty trick they do mate and it's why there is no solid standard and so many types of connectors, everybody want's you to buy their one.

 

[cumbriasteve]

Good to hear mate, for anyone else with similar problems you can buy these little media players like on here http://www.amazon.co.uk/s/ref=nb_sb_noss_1?url=search-alias=aps&field-keywords=media player&sprefix=media,aps

Even a £20 one will do the job and the beauty of them is that they connect to your tv and will play just about any format of video you can throw at it, plust audio and pictures. They are usualy remote controlled so you can control it from your armchair, some have internal hard disks to store your files on , some need you to plug in an external usb or network drive, most will accept a usb stick.
I have been using one for years and couldn't be without it, the one I have will even play stuff that vlc player on the pc won't.
Oh! and most of them will upscale to HD

Yep that's the sort of thing my mate landed with, cost him about £25.. put a USB stick in and it worked great, will get myself one without a doubt.

 

[DanielW]

They really are taking the micheal when they pluck a price out of thin air.

If it was readlly available plug it would probably cost £1.70 summat like that and the cable about 85p

How do they justify something that can be manufactured for about £10 if that.....I blame it on the yuppies back in the 80's who thought they were above everyone else,idiots.

 

[tlovatt]

With regards to the quality of the leads it's all about capacitance and long term connectivity. A video lead is a bit like a TV aerial lead, a centre core with an insulating sheath around it and then a braid around that and then an outer insulating sheath, If you imagine it in cross section, you have the metal of the central core, then a gap with the insulator in then the metal of the braid.
Well this is a capacitor, and effectively all along the length of the cable and all the way around it you have thousands of capacitors.

This is not the structure used by HDMI cables, the primary data is transmitted over 4 twisted pairs with individual screening with an overall cable screen. A lot of the more expensive cables actually just have thicker plastic coating but the primary capacitance is dictated by the couple between the twisted pairs and their individual screens.

On a cheap made lead where the central core is close to the braid the capacitance is a high value and as a high frequency is passed along the cable the charging and discharging effect of the built in capacitance will slur the high frequencies.

An expensive cable has had a lot done to reduce the capacitance, the distance between the central core and the braid is greater, this has the effect of moving the capacitors plates apart and reducing the capacitance value, the insulator around the central core is usually made with holes in it instead of being solid, thus reducing the dialectic thus reducing the capacitance.

The capacitance of HDMI cables is not generally of concern, if you look at the output driver stats for HDMI devices you will find that there is no difference in output driver levels (often floating at around 3 or 4 on a sale of 1 to 10 for a 2m cable regardless of price) Crosstalk and variations in the impedance level of individual pairs would be of greater concern.

And the other thing is the cheap leads have tin connectors or something else cheap and the dear ones are gold. When you first plug in a cheap one or an expensive one it will seem like there is no difference, but try it several years down the road, the cheap one will likely be intermittent because of tarnished connections.

Whilst gold will oxidise less than a basic tin coating, in a domestic environment if the tin contacts are tarnishing to any extent you will have much bigger problems to worry about

The con in fact is that the difference between the two leads if they are a metre even two metres long will be marginal as the capacitance effect between the two could only really be seen by an expert but as the cable get's longer and the capacitance increases the more expensive lead will have a much more obvious effect on the picture quality.

Absolutely not, there is a very very small possibility that through bad routing and other problems you could experience the dropping of a pixel or 2 (HDMI sends data uncompressed) but for all practical purposes you will either get a picture or you will not. No cable will give you better colour, sharper pictures etc. Under 5m most cat 1 cables will actually work as a class 2 anyway

 

[Flapdisk]

This is not the structure used by HDMI cables, the primary data is transmitted over 4 twisted pairs with individual screening with an overall cable screen. A lot of the more expensive cables actually just have thicker plastic coating but the primary capacitance is dictated by the couple between the twisted pairs and their individual screens.

Yes I didn't want to make it this complicated so people without an electronics degree could follow. As you state each of the rgb cables have their own individual screening and then the bundle is screened. Think of what you are saying, "Each cable has individual screening" That's exactly what I said and the longer the cable the more the capacitance between the central core and the screen.

The twisting of the pairs is nothing to do with the capacitance it's to cancell noise or hum. Where did you get your electronics training?

 

[daleyd]

A HDMI cable doesn't have RGB cores, its a data cable. What you seem to be describing is co-ax, not a HDMI cable?

 

[Flapdisk]

Yes I know that, it's digital information to give rgb though isn't it, sheeesh!

 

[ajlelectronics]

You seem to be describing a quality SCART cable rather than HDMI. An HDMI cable is closer to CAT5 than co-ax.

 

[tlovatt]

Yes I didn't want to make it this complicated so people without an electronics degree could follow. As you state each of the rgb cables have their own individual screening and then the bundle is screened. Think of what you are saying, "Each cable has individual screening" That's exactly what I said and the longer the cable the more the capacitance between the central core and the screen.

The twisting of the pairs is nothing to do with the capacitance it's to cancell noise or hum. Where did you get your electronics training?

I did not say that twisted pairs were used to reduce capacitance, what I am pointing out is that the pairs are individually screened hence the capacitance for the pairs is primarily related to their individual screen. To be picky it is the differential voltages used with twisted pairs that provides most of the immunity to noise, the twisting of the pairs, whilst it helps to balance the interference on each core is primarily to minimise crosstalk hence why the twists are done at different rates on different pairs in the cable.

I got my electronics training from University.

 

[daleyd]

It used to be an issue with cable length and the quality of cable etc back in the days when we used coax and I seem to remember capacitance/impedance would occasionally be deemed to be an issue, though generally only on longer runs and where there was high network traffic.

Since we changed over to Cat5 (Twisted pair) type cables I don't even remember capacitance being mentioned as an issue? (I generally deal with industrial instrumentation networks, so over relatively long distances, I imagine over a short cable length as you would find in a home it would be almost irrelevant)

 

[MattF]

An expensive cable has had a lot done to reduce the capacitance, the distance between the central core and the braid is greater, this has the effect of moving the capacitors plates apart and reducing the capacitance value, the insulator around the central core is usually made with holes in it instead of being solid, thus reducing the dialectic thus reducing the capacitance.

Going back a good few years, regarding the solid vs air spaced insulator, we did run some tests on some type of cable to test that. The one with the solid foam type insulator gave a marked improvement over the standard hole/air type insulator. Can't remember the specifics though, as it's knocking on twenty years ago now.

Like Daley says, I'd be surprised if even the crappiest of cables was liable to give any problems in the type of length used within a household.

 

[daleyd]

I know what you mean Matt - I seem to remember doing some theory related to coax type cables when I did my apprenticeship, but since the advent of modern network cabling it just doesn't seem to be an issue nowadays, and I have long since dumped whatever it was I learned!!

Though occasionally we still come across older installations that are still running on coax, then it becomes a fight to remember it all again!!