[jmichaelf]

What are SDI data rates compared to a media like blu-ray. Maybe I'm asking a question that doesn't make sense, but I imagine that SDI's quality difference comes from a higher bandwidth potential.


Google's looking to roll out 1gbps internet to select cities in the coming months/years and they're talking about apps that would utilize pipes that fat. My immediate thought was the end of physical media. If we can get better data rates from streaming services than blu-ray, what's the point of storing anything locally?

 

[ChrisWiggles]



Quote:
If we can get better data rates from streaming services than blu-ray, what's the point of storing anything locally?

It would seem the only point to doing things on disc might be cost of the hardware, infrastructure etc to support that. Cost aside, seems like it would make a lot of sense to a lot of people.


But a lot of people still do like to have a physical "thing" they purchased that isn't tied to one particular internet connection.

 

[jmichaelf]

I'll let you know when I get a 100mbps LTE or whatever connection on my iPhone and battery life long enough to watch a couple of high bitrate movies in a single sitting.

 

[Glimmie]

SMPTE SDI RATES:


Composite NTSC: 143mbs

Composite PAL: 177mbs

Component 535/625: 270mbs

720p/1080i: 1.485gbs

1080p/1080i/444: 3.072gbs


Now here's the caveat with IP transmission. SDI is a full payload. Meaning just about all the bits are user data. In IP, the control protocol takes up significant bandwidth so you can't put 100mbs of user data over a 100mbs Ethernet link.


So as you can summarize, there is no way a 1gbs service could carry uncompressed HDSDI.

 

[ChrisWiggles]

But it could handle compressed BD.

 

[jmichaelf]

Okay, so no SDI. Thanks for the info anyway. Full on potential 400mbps blu-ray is doable though.

 

[PeterS]

Theoretically. Of course you would need a device with significant buffer space on the receiving end to account for latency and short-term dropout issues. A new protocol would have to be developed to account for this type of data as at that speed and size of information you need to account for a variety of potential corruption issues and you would want to avoid resends as much as possible - so you would have to develop some very advanced and elegant reduction algorithms to account for it.

 

[jmichaelf]

Is there something wrong with RTP for high data rate streams?

 

[donaldk]

Glimmie those are the net datarates, overall speeds are 1.5, 3 and 4.5 gigabit for HD SDI.

 

[Glimmie]



Quote:
Originally Posted by donaldk /forum/post/18110548


Glimmie those are the net datarates, overall speeds are 1.5, 3 and 4.5 gigabit for HD SDI.

I'm not following you? 1.485gbs is the EXACT datarate for single link HDSDI aka SMPTE292. Double that, 3.072gbs is 1080/60P or single link 1080i/444 RGB. 4.5gbs? I know of no such standard.

 

[Glimmie]



Quote:
Originally Posted by PeterS /forum/post/18109952


Theoretically. Of course you would need a device with significant buffer space on the receiving end to account for latency and short-term dropout issues. A new protocol would have to be developed to account for this type of data as at that speed and size of information you need to account for a variety of potential corruption issues and you would want to avoid resends as much as possible - so you would have to develop some very advanced and elegant reduction algorithms to account for it.

This has all been done by many vendors on the professional side. However it's expensive and far from a consumer price point. Persoanlly I don't expect to see anything higher than BluRAy for home video for some time. The demand for higher bit rates in terms of image quality is just not there to justify such an undertaking. If you are suggesting some new encoding scheme, then who is going to ingest the masters tapes (which are also 4:1 compressed) into this system? Somebody has to and it's big bucks.

 

[LoKi128]



Quote:
Originally Posted by jmichaelf /forum/post/18109479


Okay, so no SDI. Thanks for the info anyway. Full on potential 400mbps blu-ray is doable though.

According to the Wikipedia Bu-ray page , the max video data rate is 54Mbps, so it should be even easier to stream over the GoogleNet. After all, some people are already streaming it over regular consumer 100Mbps networks.

 

[Kamus]



Quote:
Originally Posted by jmichaelf /forum/post/18109479


Okay, so no SDI. Thanks for the info anyway. Full on potential 400mbps blu-ray is doable though.

400 mbits? that bitrate is too high even for old codecs like mpeg2, with x264 you can get really good quality 1080p video with only 16 mbits/sec.


I'll be very surprised if people could tell the difference between a heavily compressed x264 file and the uncompressed source, x264 is that good.


It's amazing google has to step in to show the telcos where they should be bandwidth-wise in 2010, for shame really.


Having such bandwidth would change how we use applications forever.

Can you imagine loading a game like say, World of Warcraft directly from the cloud and not have to worry about patching or slow hard drives?

Howbout high bitrate HDTV on demand with channels "a la carte" at much better prices?


Some people think that the internet is "fast enough for what they do", but then, what they do is designed for really slow "broadband" connections, and they don't know what they're missing.


I'm hoping that google has enough of an impact to encourage other telcos (or new commers) to catch up with the times... everything else in computing / interfaces has gone up in speed exponentially except for broadband, and google is about to show them that it's not because of technology limitations.

 

[jmichaelf]



Quote:
Originally Posted by LoKi128 /forum/post/18120051


According to the Wikipedia Bu-ray page , the max video data rate is 54Mbps...

Quote:
Originally Posted by Kamus /forum/post/18120160


400 mbits?

According to the blu-ray faq it's capable of 400mbps, though re-reading that's at 12x. So, realtime fast forward shouldn't be a problem either!