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Broadcast formats (video/audio)

  • Onderwerp starter Onderwerp starter ajs
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ajs

Hello,

I picked up one of these set-top boxes earlier in the week and have been tinkering with things in the meantime. A lot of my observations seem to be well known, but I haven't seen any information about what form of video/audio is actually being broadcast by Ziggo. (I was formerly with Casema.)

In particular, there's no way (despite what the manual says) to pass through the video as-is ("original") on HDMI. I find this quite annoying because my TV seems to have far better scaling/processing than the Cisco unit itself. For normal SD stations, I'm guessing 576p is the way to go. But then HD stations are downscaled, which defeats the purpose of receiving anything HD. Does anyone know what format the HD stations are broadcasting? 760p? 1080i? A mixture? There doesn't seem to be any way that I can see to get the Cisco unit to display this.

Secondly, I've noticed that the EPG displays a Dolby-Digital logo next to some programs. However when I choose these, my amp still claims 2-channel PCM is being sent. (Granted my TV is receiving this via HDMI and passing out as SPDIF, but the TV is configured to pass audio through without down-mixing.) Is this consistent with what other people see? Is there a trick to getting multi-channel DD? I notice in the AV Settings that "Stereo" is the only option; it cannot be changed.

Finally, an observation on lip-sync. I've noticed that it's terrible at times and varies between stations. Changing the lip-sync option in AV settings helps a bit, at the expense of hiccups every 10 seconds or so when this setting is non-zero. I'm aware that the manual advises leaving it as 0, but does anyone have any tips for in this area?

Cheers,
- Andrew
 
Secondly, I've noticed that the EPG displays a Dolby-Digital logo next to some programs. However when I choose these, my amp still claims 2-channel PCM is being sent. (Granted my TV is receiving this via HDMI and passing out as SPDIF, but the TV is configured to pass audio through without down-mixing.) Is this consistent with what other people see? Is there a trick to getting multi-channel DD? I notice in the AV Settings that "Stereo" is the only option; it cannot be changed.

Kijk hier eens: https://ziggo-gebruikers.nl/forum/showpost.php?p=126804&postcount=214
 
Normal channels broadcast in 576i.

here is a list in what format the HD channels are broadcasting:
https://en.wikipedia.org/wiki/List_of_Ziggo_channels

as you can see, most populair HD channels use 1080i.

The problem is, that you can only choose ONE particular setting, for every channel. The cisco will NEVER adjust it automatically to the source signal. The advantage of this is, that the cisco will never suddenly change to a signal that your TV doesn't support. But a disadvantage is that if you claim your scaler of your TV is better, you have to manually change the output format of the cisco every time you change to a channel with a different source signal.

I also favor an option to let the cisco just propagate the source format so you can fully benefit the scaler of your TV if you disire so.
 
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Ok, so the verdict is that some programs have Dolby Digital but it's not the default audio stream. It turns out my TV (Philips) is doing the down-mixing to stereo. Apparently the HDCP part of HDMI forbids audio pass-through to SPDIF. (That's a fail, really.) Apparently some Philips sets (xxPFL9603/9703) used to unofficially allow it on their HDMI3 input but subsequent firmware updates removed this "feature".

On the video format topic, I agree it's a huge pity the Cisco won't simply use the program format. Especially since it varies per channel, and in my testing so far my TV upscaler is significantly better than the Cisco one.

Even if it did this, there should never be a risk of the Cisco switching to a format not supported by the TV: HDMI allows the Cisco to enquire about supported formats. (Sensible behaviour when the TV doesn't support the current broadcast behavior is debatable, but not terribly complicated.)

As a workaround, discrete IR codes for switching the video format would be most welcome. I probably wouldn't mind the lack of an "original" option if it wasn't such a pain to change via the menus. ;)
 
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