How to stream?
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20 Mar 2012, 12:47
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Journals
Hello Crossfire!
Project #et.tv have a good feedback so I decide to create a tutoria/infol about streaming, because many people asking me about stream, quality, etc.
What is livestream?
Live streaming, delivering live over the Internet, involves a camera for the media, an encoder to digitize the content, a media publisher, and a content delivery network to distribute and deliver the content, it´s audiovisual.
I want to stream? What I need to do?
First, calm down! For streaming a live games or FPS games, you must have atleast decent computer, fast harddrive, good upload and very high bandwidth.
Streaming FPS games
Be sure that you have good CPU to handle FPS! FPS can´t be less than 30! (Recommended)
Internet, upload and bandwidth
If you have limited bandwidth, you are limited to stream. Streaming is dependent of bandwidth and upload speed.
Upload
A broadband speed of 2.5 Mbit/s or more is recommended for streaming movies, for example to an Apple TV, Google TV or a Sony TV Blu-ray Disc Player, 10 Mbit/s for High Definition content.
Bandwidth
Streaming media storage size is calculated from the streaming bandwidth and length of the media using the following formula (for a single user and file):
storage size (in mebibytes) = length (in seconds) × bit rate (in bit/s) / (8 × 1024 × 1024)
The calculation for Live streaming:
Assumptions: speed at the encoder, is 500 kbit/s.
If the show lasts for 3 hours with 3,000 viewers, then the calculation is:
Number of MiB transferred = encoder speed (in bit/s) × number of seconds × number of viewers / (8*1024*1024)
Number of MiB transferred = 500,000 (bit/s) × 3 × 3,600 ( = 3 hours) × 3,000 (nbr of viewers) / (8*1024*1024) = 1,931,190 MiB
Quality -XSplit Broadcaster
Many programs are using x264 encoder. Usually Quality that is set to about 7 to 8 will produce a good quality stream and will not suck you dry of bandwidth. VBV Max Bitrate should be set to your upload bandwidth or at maximum to what download bandwidth you will require from your viewers. (We recommend using the bandwidth tester to help you figure this out). But setting high quality without providing a high enough bitrate to accommodate this will not provide the desired results - for example, setting quality to 10, resolution to 720p and a VBV Max Bitrate to 200 kbps will be non-sense.
If you set quality between 7 to 8, then we have some very rough guidelines as to what bitrate may be required for video game streaming:
VBV Buffer should be set to a value corresponding to the Flash player buffer. In several cases, an "Unknown" so set it to 1 to 2 times the VBV Max Bitrate corresponding to a 1 to 2 second Flash player buffer.
The VBV Max Bitrate is the rate at which the buffer is filled, so, technically, you should get better results with a higher buffer as this will allow the discrete bitrate of your stream to fluctuate more (as required) to maintain your required quality. But if the Flash player buffer is set to 2 seconds, you should not set your VBV Buffer higher than 2 sec x VBV Max Bitrate. You must allow for audio, but try to stick with the default values for buffer, which is automatically changed to a suggested value as you change or set your VBV Max Bitrate.
As for the Preset, "veryfast" is a good start but you should choose a preset which is "slower" if you have enough processor power. Why? Because a slower preset means that the encoder is using more advanced and more demanding algorithms/methods to compress your stream. However, you must never let any of your cores to get to more than 70% because then your stream may start to lag.
If you want to know more about VBV-Buffer, Bitrate and quality, check this out: http://www.xsplit.com/blog.php?post_id=305 !!!
Progam to stream: XSplit Broadcaster
Streaming ET: You have to run it at 1280x720 resolution and windowed mode. (XSplit doesn´t support fullscreen streaming)
I´m using for stream own3d.tv, but there are also twitch or justin. Make your decision.
I´ll make a tutorial for XSplit later, this is just for some info. If you have some questions /Q me @ IRC.
btw: #et.tv quality will be improved asap, have some HW problem now...
Source: Xsplit FAQ, Xsplit community forums, Wikipedia, Google TV, Apple TV, Streaming user guides
e: XSPLIT supports fullscreen if you have premium.
Project #et.tv have a good feedback so I decide to create a tutoria/infol about streaming, because many people asking me about stream, quality, etc.
What is livestream?
Live streaming, delivering live over the Internet, involves a camera for the media, an encoder to digitize the content, a media publisher, and a content delivery network to distribute and deliver the content, it´s audiovisual.
I want to stream? What I need to do?
First, calm down! For streaming a live games or FPS games, you must have atleast decent computer, fast harddrive, good upload and very high bandwidth.
Streaming FPS games
Be sure that you have good CPU to handle FPS! FPS can´t be less than 30! (Recommended)
Internet, upload and bandwidth
If you have limited bandwidth, you are limited to stream. Streaming is dependent of bandwidth and upload speed.
Upload
A broadband speed of 2.5 Mbit/s or more is recommended for streaming movies, for example to an Apple TV, Google TV or a Sony TV Blu-ray Disc Player, 10 Mbit/s for High Definition content.
Bandwidth
Streaming media storage size is calculated from the streaming bandwidth and length of the media using the following formula (for a single user and file):
storage size (in mebibytes) = length (in seconds) × bit rate (in bit/s) / (8 × 1024 × 1024)
The calculation for Live streaming:
Assumptions: speed at the encoder, is 500 kbit/s.
If the show lasts for 3 hours with 3,000 viewers, then the calculation is:
Number of MiB transferred = encoder speed (in bit/s) × number of seconds × number of viewers / (8*1024*1024)
Number of MiB transferred = 500,000 (bit/s) × 3 × 3,600 ( = 3 hours) × 3,000 (nbr of viewers) / (8*1024*1024) = 1,931,190 MiB
Quality -XSplit Broadcaster
Many programs are using x264 encoder. Usually Quality that is set to about 7 to 8 will produce a good quality stream and will not suck you dry of bandwidth. VBV Max Bitrate should be set to your upload bandwidth or at maximum to what download bandwidth you will require from your viewers. (We recommend using the bandwidth tester to help you figure this out). But setting high quality without providing a high enough bitrate to accommodate this will not provide the desired results - for example, setting quality to 10, resolution to 720p and a VBV Max Bitrate to 200 kbps will be non-sense.
If you set quality between 7 to 8, then we have some very rough guidelines as to what bitrate may be required for video game streaming:
VBV Buffer should be set to a value corresponding to the Flash player buffer. In several cases, an "Unknown" so set it to 1 to 2 times the VBV Max Bitrate corresponding to a 1 to 2 second Flash player buffer.
The VBV Max Bitrate is the rate at which the buffer is filled, so, technically, you should get better results with a higher buffer as this will allow the discrete bitrate of your stream to fluctuate more (as required) to maintain your required quality. But if the Flash player buffer is set to 2 seconds, you should not set your VBV Buffer higher than 2 sec x VBV Max Bitrate. You must allow for audio, but try to stick with the default values for buffer, which is automatically changed to a suggested value as you change or set your VBV Max Bitrate.
As for the Preset, "veryfast" is a good start but you should choose a preset which is "slower" if you have enough processor power. Why? Because a slower preset means that the encoder is using more advanced and more demanding algorithms/methods to compress your stream. However, you must never let any of your cores to get to more than 70% because then your stream may start to lag.
If you want to know more about VBV-Buffer, Bitrate and quality, check this out: http://www.xsplit.com/blog.php?post_id=305 !!!
Progam to stream: XSplit Broadcaster
Streaming ET: You have to run it at 1280x720 resolution and windowed mode. (XSplit doesn´t support fullscreen streaming)
I´m using for stream own3d.tv, but there are also twitch or justin. Make your decision.
I´ll make a tutorial for XSplit later, this is just for some info. If you have some questions /Q me @ IRC.
btw: #et.tv quality will be improved asap, have some HW problem now...
Source: Xsplit FAQ, Xsplit community forums, Wikipedia, Google TV, Apple TV, Streaming user guides
e: XSPLIT supports fullscreen if you have premium.
still in beta but its available. 2 year license
Number of MiB transferred = encoder speed (in bit/s) × number of seconds × number of viewers / (8*1024*1024)
All you need to worry about is upload to the destination, in your case own3d. own3d then handles the distribution. Whether you have 1 or 1 million users your upload is the same.
I mean Add screen region, edited.
at all nice initiative!
huh?
If fps couldn't be less than 30 why do you recommend the lowest possible value?
One can use any resolution he or she desires to.
+ To your edit: Streaming on 25 FPS is smooth but if your GAME FPS drops from 30>x it´ll start doing lags (stream), but only video lags, audio will be fine...