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Discussion Starter · #1 ·
I'm not sure if this has been discussed in another thread, but I just did a rough calculation on the Replay 4000 sharing feature.


Basic Assumption:

1 hour = 1 Gigabyte (let's forget about Extended/Medium/High for now)


1 Gigabyte = 1,000,000,000 bytes (let's not discuss the 1024 versus 1000 for now).


For a 2-hour movie:

2 hours = 2 * (1GByte/hour) = 2 GBytes

2 GBytes = 2 GBytes * (8-bit/byte) = 16 Gbits


For wired, home network, at 100MBit/sec:

Time = 16Gbits / (100Mbits) = 160 sec = 2 min 40 sec


For wired, home network, at 10MBit/sec:

Time = 16Gbits/ (10Mbits) = 1600 sec = 26 min 40 sec


To transfer this movie over the internet (to friend's house), at Cable Modem (1.5Mbit/sec):

Time = 16Gbits/ (1.5Mbits) = 10,666 sec =~ 3 hours


============================================


Of course, all of the above numbers are theoretical limits, which in real life are not achievable under uncontrolled circumstances:


For wired, home network: It looks like this is a reasonable amount of time, even if the network is not at peak bandwidth. Since it is basically a point-to-point copy, it is reasonable to assume that one can expect to run at close to theoretical limit. Thus, this feature is achievable and is useful.


For internet transfer: Based on personal experience as well as internet research, it seems that under normal network traffic load, one can get around only 1/3 of the theoretical limit (500Mbit/sec). You have to realize that you need this bandwidth over an extended number of hours here. Thus with this information in mind, it would take 9 hours to transfer a movie over the internet. Thus I think this feature is limited to short (30min or less) shows or for internal home use only. If possible, it would make more sense for the other side (with the Replay) to re-record the movie.


Summary:

The sharing of videos over the internet is possible only if the bandwidth is available (which we are limited by the cable modem/dsl), or we limit the content size (MPEG4). To send raw (even though it is MPEG2) video through the internet is, in my opinion, wasteful.


While we're on this subject, I would assume that the Replay 4000 must have the feature which allows a transfer to be resumed if being interrupted...


Please let me know if any of my calculations are incorrect or my reasoning invalid... Thanks...
 

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It's been established in other posts that for in-home network sharing, the video is not copied but streamed real time.
 

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Discussion Starter · #4 ·
nkopas,


You are absolutely right, I totally forgot about that. The number which I posted I was referring to the normal download speed. Thus, given that information, that would kind of make internet sharing feature (sending to a friend's house) impossible.


Also after I posted I looked at the FAQs again and found that the 1 Gigabyte = 1 hour is really for Extended recording. Thus, for Medium and High recording, it is even worse.
 

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Discussion Starter · #5 ·
BaysideBas,


I do have to admit that I did not read the other posts regarding the sharing in the home, but I disagree with the streaming of video.


Even though the wired home network do have enough bandwidth to handle the video stream, my understanding is that a "copy" actually occur, for a couple of reason:


* The time to copy is reasonable.

* The bandwidth required for streaming is significant. Using Extended quality, 20% of the theoretical limit of 10Mbit network.

* By copying, it free up the source Replay unit which might not have enough resource to handle streaming plus normal operation (viewing/recording...).


Summary: I think the entire show is actually copied from one machine to another. This free up the source machine after the copying has occurred and also free up the network bandwidth.
 

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Quote:
Originally posted by bigd
The sharing of videos over the internet is possible only if the bandwidth is available (which we are limited by the cable modem/dsl), or we limit the content size (MPEG4). To send raw (even though it is MPEG2) video through the internet is, in my opinion, wasteful
Just means it's not gonna be Napster. But you could still send something important in the background. I don' think this will be any replacement for MPEG4... nor was it intended? (Well maybe the i-channels?)
 

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Quote:
Originally posted by bigd
BaysideBas,


I do have to admit that I did not read the other posts regarding the sharing in the home, but I disagree with the streaming of video.


Even though the wired home network do have enough bandwidth to handle the video stream, my understanding is that a "copy" actually occur, for a couple of reason:


* The time to copy is reasonable.

* The bandwidth required for streaming is significant. Using Extended quality, 20% of the theoretical limit of 10Mbit network.

* By copying, it free up the source Replay unit which might not have enough resource to handle streaming plus normal operation (viewing/recording...).


Summary: I think the entire show is actually copied from one machine to another. This free up the source machine after the copying has occurred and also free up the network bandwidth.
For In-Home Video Sharing, the show is not copied from the remote machine, the data is sent directly across the network as it is watched.
 

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Quote:
Originally posted by bigd
BaysideBas,


I do have to admit that I did not read the other posts regarding the sharing in the home, but I disagree with the streaming of video.


Even though the wired home network do have enough bandwidth to handle the video stream, my understanding is that a "copy" actually occur, for a couple of reason:


* The time to copy is reasonable.

* The bandwidth required for streaming is significant. Using Extended quality, 20% of the theoretical limit of 10Mbit network.

* By copying, it free up the source Replay unit which might not have enough resource to handle streaming plus normal operation (viewing/recording...).


Summary: I think the entire show is actually copied from one machine to another. This free up the source machine after the copying has occurred and also free up the network bandwidth.
I guess that you know better than the Replay folk who have stated otherwise:D :D :D


Well, that's what happens when you're interrupted while formulating a reply. Never mind, ReplayPatrick beat me to the punch.


And put on your thinking cap for a moment. Copying the program for shared watching would mean tying up recording space on the remote machine. Not so smart, is it?
 

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As for the high quality show soaking up a startling N% of your 10Mb/sec ethernet:


I think that's why they put a 10/100 ethernet on it.
 

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I'd say they put in a 10/100 because with todays hardware, a 10mb would probably cost more than the current standard 10/100 cards on the market. Having used an early 10mb networked MP3 player, the extra headroom of 100mb will be much better for these units when downloading data to/between units and PC's that 10x speed increase is great.
 

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This still doesn't examine the sharing speed...


Road Runner in Austin is quoted as having upload speeds of up to 300 Kbps....


Looking at the a two hour movie, and using the fun and handy convert.exe program "computer" tab (A VERY good program, it is free at http://www.joshmadison.com/software/convert/ )


1 Gigabyte = 8,388,608 kilobits


A two hour movie will be:


Standard: 16,777,216 kilobits (2 gigabytes)

Medium: 33,554,432 kilobits (4 gigabytes)

High: 50,331,648 kilobits (6 gigabytes)


So, on my Road Runner system, it will take me 15-1/2 hours at standard, 31 hours at medium, and just over 46-1/2 hours at high, to send a two hour movie -- ASSUMING, that I get the maximum upload speed possible.


This also assumes they send the raw mpeg 2 video files.


Half-hour shows are more reasonable, taking 1/4 the time above. That's still nearly 4 hours for a 1/2 hour show recorded at standard.


In addition, in the "acceptable use policy", subscribers agree to not "Connect High Bandwidth server applications on their Residential or Road Runner Business Pro Account. This includes but is not limited to the running of servers for FTP; HTTP, IRC, DHCP, Mail and multi-user interactive forums (i.e. game servers)"

This isn't exactly a server application, but if I am uploading video at 300 Kbps for 15-50 hours they may take notice.


At 100 Mbps, home lans may be able to transfer streaming video -- but will broadband file transfer be real?


Joe
 

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Discussion Starter · #12 ·
DrJoe,


The numbers are really scary, isn't it?. After analyzing all these numbers, I don't think "internet sharing" is a possible thing, at least not yet.


For one thing, I really don't want my neighbor (who is sharing my cable modem bandwidth) to send 10Gigs down the pipe...:D


Any ReplayTV application engineer please comment...
 

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I agree that those numbers are scary, but assuming your ISP doesn't care, I don't see why anyone here would. So what if it takes long. I have downloaded stuff off of Morpheus that took 3 days. You just let it run in the background. In fact, you won't even notice it on your PC. I think the benefits are huge. It can take care of conflicts if you find a partner willing to record the other show for you. Then just send it to eachother, wait a day, and its there. I like it!
 

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Quote:
Originally posted by bigd
The numbers are really scary, isn't it?. After analyzing all these numbers, I don't think "internet sharing" is a possible thing, at least not yet.


For one thing, I really don't want my neighbor (who is sharing my cable modem bandwidth) to send 10Gigs down the pipe...:D
Keep in mind this will not be your primary source of content. And do you think @ this price range more of your rr neighbors will be sending 100k/sec of these (round the clock) than are already sending 100k/sec of WinMX/KaZaa/Bearshare/ who knows what?? round the clock? Think of this (internet send) as an added feature not a replacement to the MPEG4's you already send down @ 10 gigs per xx?? :cool:?? Just a perspective...
 

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Other than the transfer feature why would one buy a 4000? I use a device I got from X10.com called a video sender that works great and cost about $80. I see little for $700 and up to make me want a 4000



Sundance
 

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Sundance you can check these:
http://www.replaytv.com/partners_products/features.html

If none of those interest you or are of use to you then maybe you won't need one.

I will be curious about the Commercial Advance in addition to the line doubler and since I can't tolerate the video quality of the X10 solution I prefer a digital transfer so I am interested in the "housewide" ethernet connectivity.
 
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