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Streaming bitrates

5767 Views 8 Replies 6 Participants Last post by  Hyrax
Can anyone tell me what sort of bit rates to expect from HD videos Netflix and Amazon?

I've got them available on my Roku 2, PS3, and my Tivo and I'd like to know if a movie is available on both services which service should I choose. When I look at them they look pretty similar, but there are sections in some videos where things look a little fuzzy at times. Comparing them side by side is impossible, so I was thinking I should just go with the one that is most likely to have the highest bit rates. I've got a high speed internet connection that seems to be very stable - I almost never see the video quality change after a few moments of the start while watching a video.

Thanks in advance.
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Netflix uses an adaptive speed technology. Its bitrate depends on the quality of your network connection. I don't know for sure about Roku, but I suspect it does, too. They'll both vary depending on the time of day and how busy your local network is.

In other words, if you want the best reliable video and audio quality, you need to use "shiny discs."

Originally Posted by Selden Ball  /t/1414999/streaming-bitrates#post_22121467

In other words, if you want the best reliable video and audio quality, you need to use "shiny discs."
would that I could. There are a surprising number of movies that I can stream in HD, but I can only buy a terrible quality DVD. 'The Black Stallion' is one such movie, it isn't even anamorphic. Why Francis Ford Coppola has not reissued the movie is beyond me.

My question really is which service tries to deliver the highest bit rates assuming that adaptive speed technology does not kick in and slow things down.

Zune/Vudu/itunes deliver 1080p at about 10 mbit.... Netflix/Amazon/HBOGO/etc all deliver 720p at roughtly 5 mbit.
Good info, thanks. I assume you mean HDX is 10 mbit. Do you know the bit rate of their (Vudu) 720P streams?
As an aside...I noticed Zune's download size (for purchase) for movies averaged 9-10GB. Of late, many of the movies I have DVR'ed from Dish are only around 3gb. Older movies I have recorded averaged about 4GB. I watched Mission Impossible 4 (HDX) on VUDU (PS3) and the quality was pretty good. I haven't seen the Bluray yet though.
This topic has been touched on many times in other threads, 'michaelscott' is pretty much the resident expert when it comes to bit rate information on the various services.

Last night I watched an HD (stereo) title on Netflix using my WDTV Live streamer. Here is the graphic taken off my router using the Tomato firmware.

You can see the adaptive streaming at work which is quite different from VUDU HDX which seems to lock in at a high bitrate and stays there until the downstream completes.

Netflix HD

netflix_HD_bitrate.jpg 105k .jpg file


vudu_stream.jpg 71k .jpg file


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Sorry--I haven't checked this forum since the forum software change. I answered a similar question recently in another thread:
Originally Posted by michaeltscott  /t/1348657/official-roku-2-media-streamer-thread/600_100#post_22110403

Originally Posted by Andy's Woodwork  /t/1348657/official-roku-2-media-streamer-thread/600_100#post_22110194

Anyone know the Minimum MBPS for the Roku ?......

Roku runs dozens of different video services and all of them will have different bandwidth requirements. Presuming that you're talking about Netflix (and this goes for any device streaming Netflix, not just Roku), a title with HD video will have encodings at 235-, 375-, 560-, 750-, 1050-, 1400-, 1750-, 2350-, 3600- and 4800 Kpbs. 2350 and 3600 are 720p24, 4800 is 1080p24 and all the rest are 480p24 (p30 for older TV or p25 for British content). Add 192 for stereo sound or 384 for 5.1 channel DD+ (for that subset of titles with 5.1 sound). Multiply by 1.3 and you'll get roughly the amount of bandwidth necessary to sustain that encoding. This will vary a little with the title, since the encodings are typically highly variable bit rate; you might manage to stream the 1080p encoding of a non-action title for significantly less bandwidth than the 6.7 Mbps that my forumula indicates.

There are so many encodings because Netflix on newer devices (and PS3, Xbox and the PC web player) uses some tech called Adaptive Bit Rate Streaming. To put it in simple terms, the player will read content as fast as it can until it fills it's buffer; if it cannot keep the buffer full with its currently selected encoding it will request the next lower quality, lower bit rate encoding; if it's keeping the buffer full easily it will try a higher bit rate encoding with higher picture quality. If it changes encodings it will do it smoothly without pausing; on the best players this looks like the focus of a lens becoming gradually sharper or softer. The bit rate that a player can keep up with depends on multiple factors, principally available bandwidth on your connection to Netflix's servers and those servers' current responsiveness; if you can accept content faster than your server can find time to shovel it to you, it won't do you any good. Note that available bandwidth on your connection to Netflix's servers is somewhat independent of your Internet service's rated speed--that's only a limit, and you're not guaranteed to get that on a connection to any arbitrary node on the net.

VUDU tops out at around 9 Mbps and Zune at around 10 Mbps for 1080p24 with various kinds of digital surround sound. iTunes gets up to about 5.4 Mbps. All of these are as calculated from downloaded file sizes by msgohan in his " Netflix PS3 streaming comparison PIX " thread, cited at the top of posts like this one.
Thanks for all of the great information. From experience it seems to me that the Roku 2 and the PS3 both do a good job with Netflix HD material (I've been using the Roku 2 mostly). The Tivo usually does a good job, but there are occasional black outs during prime time that drive me nuts. My 2011 Panasonic BRD does the worse job, but I never intended it to be used for streaming - I keep it offline to speed up its startup. I'm too cheap to pay for Vudu's HDX titles, but those data rates make it look tempting.

I just tried HBO Go, and my first impression was that it looked really good. I'm going to compare their Game of Thrones to my Blu-Ray version and see how different it might be.
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