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Confused over streaming compression settings
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david Eadenhall What is the difference between progressive download and streaming. When i am compressing my video, how do I know what type of download I am compressing for (progressive or streaming)? I have a streaming server set up so that my users can use the ‘seek’ function, will both these types of download be compatible with this, or is there one in particular that i should go for?
Some of this may not be technically perfect, but it’s a general explanation of the difference.
Progressive download sends the file (usually to a temporary location on your computer) to each end user, while true streaming feeds the video in real-time to end users (often called Video on Demand or VOD) or multicasts it to many users without having to actually cache or download it to your computer.
When they’re both done correctly, end users usually don’t see a difference between the two, as they both play the video as if it’s in real-time.
Streaming is usually used for live webcasting, like what CBS did with the NCAA basketball tournament and NBC the Olympics, while progressive download is typically used for produced content.
There are exceptions of course, like when a corporation conducts traning via the internet and hundreds or even thousands of employees watch a pre-produced video. Of if your videos are so popular that hundreds of people may be watching your videos simultaneously. Or when a company does an online web event or promotion.
Streaming is usually more expensive because to do it reliably requires server side software and programming, and sometimes even special server hardware. It also uses a special transport protocol. Progressive download is less complicated and uses regular HTTP for sending files, and videos can often be stored right on your web server. Again…there are exceptions, as freely available software has streaming server capabilities built in, like VLC and others, but it’s not for the faint of heart to set up.
Progressive download will start playing after only a few seconds of video has downloaded and continues to play as long as the download stays ahead of playback. You can also program in buffer or load times into flash metadata (the instructions that are typically part of a player skin that wraps the flash video) to ensure that a certain amount of the file downloads before playback begins, which helps keep the download ahead of playback. Some of the Flash encoding apps even offer simple options that allow you to specify the buffer time when encoding the video.
There are probably some technical things I haven’t got quite correct, but that’s the basic difference.
Here’s some quick, concise articles that are helpful in explaining things further.
https://www.mediacollege.com/video/streaming/server.html
https://www.streamingmedia.com/article.asp?id=10952&page=1
As for encoding your video, virtually all the encoding we do is for progessive download, so I’m no help when it comes to preparing media for true streaming. But I don’t think there’s a whole lot of difference other than making sure it’s coded to stream, and it’s data rate is constant (CBR) as opposed to variable (VBR).
Others can probably explain the requirements better. But more than likely, progressive download will work for the majority of web video.
Chris Blair
Magnetic Image, Inc.
Evansville, IN
http://www.videomi.com -
There are a few major differences between Progressive Download and Streaming.
Progressive Downloads can be delivered from a normal webserver via HTTP
Streaming requires a dedicated streaming server and uses RSTP (Real Time Streaming Protocol)Progressive Download saves a file to the viewers hard drive, as such it’s very difficult to stop that file being copied.
Streaming delivery saves nothing to the hard drive.With progressive download, you as the content creator, or owner controls the quality of the picture, users on all types on connection speeds see the same quality picture. Those on slow connections have to wait longer before they can start playing the video.
With streaming, the quality of the picture is determined by the viewers connection speed, those on slower connections sometimes see little more than digital soup, or if they do get a picture it seems more like a sequence of pixilated stills.
Progressive download is not suitable for long clips. say over 15 minutes
Streaming is suitable for long clips, even full length movies.Most Flash delivery is progressive download.
VoD, or Video on Demand can be either.
Compressing for each is roughly the same only that when compressing for Streaming you have to pay strict attention to realworld bitrates. If for example you are targeting users on a 500kb/s connection, you wouldn’t want the total datarate (audio & video) of your video to go over 425kb/s. With progressive download that could be as high as 1500kb/s.
When compressing for progressive download you can use CBR or VBR rate control, with streaming you can only use CBR.
There’s much more, but those are the basics.
Hope that helps.
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Two years from now, spam will be solved. – Bill Gates, World Economic Forum 2004 -
[Chris Blair] ” while true streaming feeds the video in real-time to end users (often called Video on Demand or VOD”
Not quite, VOD has nothing to do with this, VoD is simply a type of service and can use either type of delivery method.
[Chris Blair] “When they’re both done correctly, end users usually don’t see a difference between the two, as they both play the video as if it’s in real-time. “
Progressive downloads will generally always be higher quality. Full HD can be delivered easily by progressive download, that’s nearly impossible for most people via RTSP.
[Chris Blair] “Progressive download will start playing after only a few seconds of video has downloaded and continues to play as long as the download stays ahead of playback.”
Not quite, the time it takes for the clip to start to play is based on a combination of the viewers connection speed, the size of the file, and the length of the clip .
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Two years from now, spam will be solved. – Bill Gates, World Economic Forum 2004 -
Dear Chris and Daniel
I just cant believe this site – the fact that two pros are taking the time to explain all this to me. I have spent months reading and re-reading up on all this and have not been able to take in this info. Its only since you both have taken the time to help me that I can finally understand this. Sorry to sound like a broken record, but thank you ever so much.
Well I have a server with a Wowza media streaming server installed. The reason that we went for a media streaming server is so that my viewers would be able to ‘seek’ to any part of the video and have it download from that point. I like the idea of being able to set my own bit rate to force the video to play at, so that I know how the end result for my viewers will look. So the sacrifice of this is that users with slower connections will have to wait longer before being able to start viewing if I go the progressive route?
Can one use the progressive download option with a media streaming server, or is that only for real streaming?
Am I right to believe that using a VBR is better than a CBR for progressive download?
I have tried compressing videos using Final Cut Pro, Quicktime Pro, Mpeg Streamclip and Adobe Media Encoder but there has been no apparent setting to choose whether my final compressed video is going to be for progressive download or true streaming – am I missing a setting here or do other parameters govern this? Maybe I have overlooked something here. I only seem to be able to set frame rates, data rates, frame sizes, quality, deinterlacing, CBR/VBR etc.
Thank you again
Dan
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[david Eadenhall] “So the sacrifice of this is that users with slower connections will have to wait longer before being able to start viewing if I go the progressive route?”
Yes.
[david Eadenhall] “Can one use the progressive download option with a media streaming server, or is that only for real streaming?”
No need (you just need a simple webserver for progressive download) but it’s probably possible, have a chat with the Wowza support guys.
[david Eadenhall] “Am I right to believe that using a VBR is better than a CBR for progressive download?”
It depends on the kind of content; a simple interview, for example, will not benefit from VBR, an action movie would.
VBR will make for a far more efficient encode, meaning the file size will generally be smaller, as it has allocated data more meaningfully. 2-Pass is the the best way to encode VBR. Actually 2-pass is the best for CBR too. If you have the luxury of time.Final Cut, MPEG Streamclip and Quicktime Pro are not the tools of choice here. Adobe Media Encoder is pretty good and should have presets for both streaming and download, I don’t use it so I can’t be sure.
The best tools for the job are Apple compressor (which you should have) and Episode.
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Two years from now, spam will be solved. – Bill Gates, World Economic Forum 2004 -
Hi there Daniel and Chris
I would ideally like to make my videos available via progressive download as the idea that I can control the quality that ALL my viewers will see, really appeals to me. I wouldnt really be happy knowing that if I stream my material, some viewers will think my videos are poor quality because they dont realise that the speed of their connection is making these videos look bad. The picture quality of my videos is very important really, as its a shame to destroy the quality from our HD source.
I would also like to make my videos available for download to a hardrive (in a zip folder) as well as for immediate viewing online. That way I can be confident that whatever set up our user will have, they will be able to actually view the videos in some way.
My question is if I offer a video for progressive download and also for download via zip, am I effectively going to double my bandwidth usage (users might progressively view the video online, then decide to download a copy to their hardrive). If I decided to stream the video instead, so the user could still view the video right away before deciding whether to also download a zip copy, would that use up alot less bandwidth?
If one views progressive downloads in a normal browser, can you still have the option of being able to maximise the video to full screen, or are you limited to the exact frame size of your original video file in the browser?
Once again, thank you ever so much for all your help over the last week, Im just so appreciative to you!
Dan
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[david Eadenhall] “My question is if I offer a video for progressive download and also for download via zip, am I effectively going to double my bandwidth usage”
Yes, pontetially if it the same video you use for both types of downloads.
[david Eadenhall] “If I decided to stream the video instead, so the user could still view the video right away before deciding whether to also download a zip copy, would that use up alot less bandwidth?”
Yes, if the streaming clip is at a much lower datarate than the downloadable zip version.
[david Eadenhall] “If one views progressive downloads in a normal browser, can you still have the option of being able to maximise the video to full screen, or are you limited to the exact frame size of your original video file in the browser?”You are limited by the capabilities of the browser and the browser plug-in. What player are you considering using? If it is a Flash player you’ll need to script a button that will allow it to playback at fullscreen.
Alternatively, look at the way Apple delivers it’s HD Quicktime movies: https://www.apple.com/trailers/#section=justhd
Anyone with Quicktime Pro (or Quicktime Alternate) can save any of these movies directly to their hard drives and only use up the bandwidth once.
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Two years from now, spam will be solved. – Bill Gates, World Economic Forum 2004 -
Hi there Daniel
I cant believe how quickly you responded!!!!!
I have Flowplayer on my server that I am currently testing with our videos. Is this s a good choice?
Those Apple trailers consistently stun me, the quality, the content, the immediacy etc – sensational! What sort of compression techniques do they use, its unbelievable?
How have they been able to allow the users to only use the bandwidth once by watching and saving the file in one go – that sounds like the perfect solution?
Thank you so much my friend
Dan
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I don’t have any direct expereince with Flowplayer but it appears to have a fully featured toolset including a bandwidth checker:
https://flowplayer.org/plugins/streaming/bwcheck.html
[david Eadenhall] “Those Apple trailers consistently stun me, the quality, the content, the immediacy etc – sensational! What sort of compression techniques do they use, its unbelievable?”
They get hold of the best quality source content to start with and have a team of skilled compressionists working to generate the outputs using a variety of software encoders including compressor and cleaner. Nearly all content is encoded to H.264.
[david Eadenhall] “How have they been able to allow the users to only use the bandwidth once by watching and saving the file in one go – that sounds like the perfect solution?”
As the file is being progressively downloaded, it’s already there on the hard drive, the Quicktime player then just enables the saving (moving) of it to a convienient location for the user.
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Two years from now, spam will be solved. – Bill Gates, World Economic Forum 2004 -
“As the file is being progressively downloaded, it’s already there on the hard drive, the Quicktime player then just enables the saving (moving) of it to a convienient location for the user.”
Is this possible to set up on my server, or is this a very complicated process to go through? This surely would be an ideal solution.
Take care my friend
Dan
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