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Discussion Starter · #1 ·
Hi all,

Can someone help explain briefly about bit rates and HD resolution (ie 480/720/1080) with respect to streaming content to a HDTV.


My confusion arises due to the fact that streaming sites such as netflix stream at rates between 300Kbps to 3600Kbps(approx). But most people refer to content by its resolution ie 720/1080p and that bit rates for SD TV/DVD/and HD are as follows(approx)...

3.5 Mbit/s std def

9.8 Mbit/s DVD

10-20 Mbit/s for 720-1080


Basically, I am trying to understand the quality level of a video stream when advertised as Kbps(as netflix above), in terms of how it will look on a HDTV.ie will is be 480/720 or 1080p quality


thanks
 

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You are already understanding it pretty well. However the encoded rate is not the same as streaming. Streaming is just the speed at which the content server and your ISP can deliver the video to your computer. Netflix does not stream High Def, so 720 and 1080 are out. There quality is just below DVD quality.


To get true hd stream you would need a about a 20 Meg pipe, and for some titles that would still require a buffer to play. That's not to say a 5 Meg pipe couldn't stream a bluray quality movie, it would just require alot of buffer before hitting play.


1024 Kbps= 1 Mbps
 

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Quote:
Originally Posted by TornadoTJ /forum/post/19621029


They do, actually.

And that gets into "what really is HD". All the providers/marketers go simply by resolution. 1080p at 5mbps is not HD in my eyes when broadcast is 4 times that and Blu-Ray 10 times that. (Granted there are different codecs/compression schemes).
 

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Discussion Starter · #5 ·
forgive me if I'm missing something, but hulu's website says they use"between 480Kbps and 700Kbps", so that would be half of std def and netflix delivers up to approx 3600kbps which is barely stdef, correct?


Vudu claims they broadcast HD upto 1080p but this would require a connection speed of at least 30Mbps which very few people have. Something is not adding up


3.5 Mbit/s std def

9.8 Mbit/s DVD

10-20 Mbit/s for 720

30 Mbps for 1080p

40 Mbps for BD


capaill
 

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Quote:
Originally Posted by capaill /forum/post/19621903


forgive me if I'm missing something, but hulu's website says they use"between 480Kbps and 700Kbps", so that would be half of std def and netflix delivers up to approx 3600kbps which is barely stdef, correct?


Vudu claims they broadcast HD upto 1080p but this would require a connection speed of at least 30Mbps which very few people have. Something is not adding up


3.5 Mbit/s std def

9.8 Mbit/s DVD

10-20 Mbit/s for 720

30 Mbps for 1080p

40 Mbps for BD


capaill

What you found is correct. HD has become nothing but a marketing term and poor quality. HD is now in the eye of the beholder.
 

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Quote:
Originally Posted by primetimeguy /forum/post/19621167


And that gets into "what really is HD". All the providers/marketers go simply by resolution. 1080p at 5mbps is not HD in my eyes when broadcast is 4 times that and Blu-Ray 10 times that. (Granted there are different codecs/compression schemes).

You tell me, the full quote says "720 and 1080 are out". But that's not true. It may have a low bitrate, but 720 and 1080 are possible on Netflix.
 

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Quote:
Originally Posted by capaill /forum/post/19621903


forgive me if I'm missing something, but hulu's website says they use"between 480Kbps and 700Kbps", so that would be half of std def and netflix delivers up to approx 3600kbps which is barely stdef, correct?


Vudu claims they broadcast HD upto 1080p but this would require a connection speed of at least 30Mbps which very few people have. Something is not adding up


3.5 Mbit/s std def

9.8 Mbit/s DVD

10-20 Mbit/s for 720

30 Mbps for 1080p

40 Mbps for BD


capaill

Resolution are different, and completely indepenent things, you can't equate one to another. For example raw SD video is about 10Mbps, which is actually more data than some HD content.


The way it works is:

SD refers to 480i or [email protected]

"ED" which was a popular term before HD sets really took of is [email protected]

HD is basically anything 720p and up.

"Full HD" is generally 1920x1080p (either either 24p or 30p).


Separate from that there is bitrate, which affects (but is not necessarilly a measure of) quality at a given resolution. This is where things get very fuzzy because bitrate, resolution, source quality and compression scheme all factor into final image quality.


Realistically, with modern codecs (H.264, VC1, etc) you can get reasonable quality SD with as little as maybe 300kbps.


Netflix does reasonable quality 720p HD with 3.5Mbps or so, satellite providers tend to give more like 5-6Mbps for H.264 HD (1080i).


1080p could quite easilly be done in the
 

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Discussion Starter · #9 ·
stanger89, thanks

how did you get netflix's bit rate?
 

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Discussion Starter · #10 ·
Anyone willing to suggest a minimum bit rate that will look watchable (I know this is up for debate, lets just say not stuttering/blurry/no dropped frames) on a 50"HDTV


I understand this depends on 1. Internet Bandwidth, 2. Computer processing power.

Assuming bandwidth is fine, if my PC is running at 80-90% (worst case) will this only result in dropped frames only or will the bit rate also get re-adjusted.
 

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Quote:
Originally Posted by stanger89 /forum/post/19622295



Personally I rank netflix's 3.5/3.6Mbps "HD" as roughly "DVD Quality" it's got a similar amount of detail and artifacts, despite being higher resolution.

Exactly. They market it is HD and 1080p, but it is no better than DVD.
 

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Quote:
Originally Posted by capaill /forum/post/19622493


stanger89, thanks

how did you get netflix's bit rate?

I've seen it posted a few times on the forums. I think on the PC you can pick quality, which is where the info was gleaned from. It's possible standalones have a higher bitrates available but I've never really checked.

Quote:
Originally Posted by primetimeguy /forum/post/19622633


Exactly. They market it is HD and 1080p, but it is no better than DVD.

Right, but that's different than (in the context of this threads question at least) saying it's not "HD". HD is just a simple metric describing resolution, nothing more.
 
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