Two FoxT2s playing through the same TV displaying differently

[Trev]

The other advantage of interlace in the old days was phase alternate line (PAL) whereby the phase of the coloyr info was reversed, so any phase error on the colour sub carrier signal was 'averaged' out, thus perceived colour rendering was improved considerably when compared with NTSC and SECAM

 

[Black Hole]

That's not an advantage of interlacing, it's using alternate fields to avarage out colour information transmission errors - that could be done just the same using a non-interlaced system.

For an interlaced system the fields are half-frames, so the colour content of a PAL system has half the spatial resolution and half the temporal resolution of the luminance content. If it were a non-interlaced system the colour would have full spatial resolution (but still half the temporal resolution).

This definitely wouldn't qualify as HiDef!

 

[prpr]

phase alternate line (PAL) whereby the phase of the colour info was reversed, so any phase error on the colour sub carrier signal was 'averaged' out

And generated a (mostly un-noticeable) saturation error instead of a (quite noticeable) hue error.

 

[EEPhil]

[Deja vu yet again] NTSC - Never Twice the Same Colour - known as that for a reason.

 

[Owen Smith]

Freeview HD channels switch dynamically between 1080p25 and 1080i50 depending on what the encoder thinks of the video. If you leave the Humax info display up you will sometimes see it change every few seconds between 1080p and 1080i, it doesn't show the frame rate. The most common change is at the end of a programme when the credits start, the channel switches from 1080p25 to 1080i50 because there is continuous motion in rolling credits and the encoders clearly think this is better at 1080i50.

 

[Black Hole]

1080p has twice the HDMI data rate of 1080i

Are you serious?
When all other aspects are equal the video data rates for a whole frame are the same.

OK, so when a V-FORMAT setting of 1080p results in the TV signal being obliterated, but 1080i solves the problem, that's because it has the same data rate is it?

(I bring this up now, because I have just had to do exactly that.)

 

[Owen Smith]

1080p as output by the HDR Fox T2 is 1080p50 which has twice the data rate of 1080i50.

Freeview HD broadcasts in either 1080i50 or 1080p25 switching on the fly depending on content. How well 1080i50 can convey 1080p25 is open to debate and the conversions in your TV, but if we're going to worry about time alignment of fields and frames we also have to consider how the encoder handled such issues.

 

[grahamlthompson]

OK, so when a V-FORMAT setting of 1080p results in the TV signal being obliterated, but 1080i solves the problem, that's because it has the same data rate is it?

(I bring this up now, because I have just had to do exactly that.)

After setting a HDR-FOX-T2 to output 1080p. The signal is deinterlaced to produce a 25fps progressive stream (if not already 25p) Each frame is then transmitted twice to create a 1080p50 data stream so it has twice the original data rate. A TV with a HDready 1080p spec is required to display 1080p50 (and also 1080p24). Guessing your TV is an older HD Ready design. These can display 1080i but not usually at a 1:1 source to display as these generally do not have 1920 x 1080 pixels. The pixels on such a display are not square.

See the table here comparing the two specs

HD ready - Wikipedia

en.wikipedia.org

 

[Stummery]

I said in a recent thread that jack616 taking 78 days to reply to a post might be a record.
We might have a new leader with BH taking 571 days

 

[Black Hole]

After setting a HDR-FOX-T2 to output 1080p. The signal is deinterlaced to produce a 25fps progressive stream (if not already 25p) Each frame is then transmitted twice to create a 1080p50 data stream so it has twice the original data rate. A TV with a HDready 1080p spec is required to display 1080p50 (and also 1080p24). Guessing your TV is an older HD Ready design. These can display 1080i but not usually at a 1:1 source to display as these generally do not have 1920 x 1080 pixels. The pixels on such a display are not square.

Are you saying the TV can control what the HDR-FOX actually sends on the HDMI? If not, it's irrelevant whether the TV is old or new. In fact, I have experienced this Lo(UHF)S with 1080p v 1080i on a Samsung UE32EH5000AK and a JVC LT-40C590 (neither of which are only "HD Ready"!!!).

 

[grahamlthompson]

Are you saying the TV can control what the HDR-FOX actually sends on the HDMI? If not, it's irrelevant whether the TV is old or new. In fact, I have experienced this Lo(UHF)S with 1080p v 1080i on a Samsung UE32EH5000AK and a JVC LT-40C590 (neither of which are only "HD Ready"!!!).

Of course the TV can control what the box outputs. It's all part of the HDCP handshaking between a source and a display device, Amazed you don't know this already.


All HD Tv's exchange this information during the HDCP handshake. If the TV says it cannot do 1080p 50, the source will withold the the video. If you split the hdmi out to feed 2 displays. The output of the box switches to the lowest common parameters. If you split the output of a HD channel a and both destinations do not support ac3. then the box switches to PCM stereo.

The destination device tells the source what it is capable of during the handshake. Look up EDID data.

If you connect a blu-ray player to a TV that can't synch to 24 HZ content the player uses pull down to output at 60Hz. This creates motion artefacts. Most bluray content is 1080p24. In fact blu-ray cannot do 1080p50.

 

[Black Hole]

That's as may be, but my TVs have no need to control the 'FOX output. Both the Samsung and the JVC report 1080i50 and 1080p50.