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Best compression for the web
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Guys,
Thank you very much for your replies. I got some good notions from them that helped clear things up.
Still the mystery of the unhappy client remains unrevealed…It all started because the client reported that , when viewing the video on his website (the 9megabyte sized, 586×320 framesized and 1m:35s long motion graphic presentation, delivered in streaming) it would start, and then stop a couple of times during playback; you know, as if it was waiting for the loading, and then continue until the end (always stopping and going).
My first two ideas were:
1) decrease file size
2)compress it with CBR (since i’d read that if you’re streaming it, you must use cbr).Yet you say that 9megabytes would present any problems, either in streaming or http video. So file size is not the issue ? Maybe the VBR vs CBR ? Any ideias?
note: i decreased the fps from 25 to 15 (still in AE) and i got a some reduction in file size but i also changed some other aspects so i really couldnt say its a magic potion. I guess compression is a “try, change and re-try” thing.
note 02: What i was trying to say with the noise was that the image gets pretty sloppy with compression. Pixelated. Not captured video noise. Could this be helped with compression filters ?
Sometimes it gets pixelated and then smooth out, to get pixelated again and so on – could this be related to the amount of keyframes we set in when compressing ?cheers
Tiago
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You really need to tell us how this file is really, truly, actually being delivered – either from a Flash Streaming Server OR from a web server using HTTP.
Then you need to tell us what the datarate of that file is. NOT its file size.
As I said in my last post if the file is 9 MegaBytes per second then most people will have a problem viewing it over the internet, streamed or downloaded.
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Sent from my iPad Nano. -
Its being delivered from a local web server, not the flash server.
800 MB avi uncompressed (original file)
compression: 250 kbps
keyframe every 300 frames
On2VP6 Pro 2 pass CBRGot an 9MB FLV.
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[Tiago Casais] “compression: 250 kbps
keyframe every 300 frames
On2VP6 Pro 2 pass CBRGot an 9MB FLV.”
and your frame size
586×320That’s a pretty low data rate given your frame size. You have two choices. Go to a smaller frame size or increase the data rate to get rid of pixilation.
If the viewer is seeing pauses at that data rate on a CBR file, there’s either an issue with the server or he’s got some serious issues on his computer or internet connection IMHO. Maybe he should empty his browser cache as well at progressive download is buffered.
Back to quality, I’d use H.264, not On2VP6. H.264 works fine in flash on modern computers with recent versions of Flash going back a couple of years. I’d recommend 2 Pass VBR encode so bits can be allocated to the parts of the content that need it.
Again if he’s getting pauses on a 250kbps CBR file from an HTTP server there’s problems that may not be related to the file.
What’s his internet speed? Even a 384kbps slow DSL connection should handle what’s being served though. BTW the speed his ISP tells him he has may not be reality.
Reality (speed)
https://www.speedtest.net/
Reality (ping and stability)
https://www.pingtest.net/ -
Im sorry, he was havind this issues with a VBR compressed file that was used earlier. The CBR compressed file im talking about is the new version that replaced the troubled one. I still havent got any reply on that matter so I cant say for sure if the “VBR to CBR” change was of any good at all. I also cant say anything about the clients connection at this moment, but im sure its not the best one since i never had any troubles viewing the flv at any time.
You say i should use VBR, and im sure that would improve quality, but isnt that the primary suspect for the stop/go problem the client had ?
Im still not sure about the relation between CBR/VBR vS streaming/http progressive(?). Can you give me some hints on when to use one or the other ?
Also, squeeze doesnt allow using h264 for flv delivery. only for .mov. Any other compression software you recommend?
cheers
Tiago -
Tell him to get faster internet connection 🙂 In all seriousness, it could be his connection. Also check the server. Is this your server? A friends host server? An actual company server? If so, big company or small? At my work we use a CDN just for the reason of delivering our videos. The CDN has server locations almost evenly spaced out over the US in major cities so the latency is reduced. I might start to sniff out if it’s a delivery issue because it sounds like you may have fulfilled your obligation.
Drew Jensen
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[Tiago Casais] “You say i should use VBR, and im sure that would improve quality, but isnt that the primary suspect for the stop/go problem the client had ? “
It could be if the client has a very slow or unreliable connection. The parts of the file that use more bits will take longer to buffer. If the buffer takes longer to fill at a given point, their playback will pause. It’s quite possible that a 250kbps file might have peaks that are several times that. In a professional compression utility you can constrain those peaks though. You REALLY need to know the target. It’s a MAJOR factor in your choices as a compressionist.
As someone who advises my clients, if I had a client with the experience your client is having, I’d have them run the aforementioned tests. If they don’t like the results they should contact their ISP and if the results aren’t satisfactory, they should switch ISPs. This is assuming video is important to them as it seems it is.
Imagine driving a car that stalls every 2 minutes. Now if you don’t really need to drive a car that often maybe you don’t care. If you do need to drive the car as part of your business you either get the car fixed or get another one.
If every time they ask someone to make a video file for them the provider (you in this case) has to spend 10 hours on what should be a one hour job, you’d stop wasting your time with him as well every other provider of video files. If his car can’t get him to the business meeting on time then his business will go under. And yours will too if you have to spend 10 hours on a job that bills one hour.
[Tiago Casais] “Im still not sure about the relation between CBR/VBR vS streaming/http progressive(?). Can you give me some hints on when to use one or the other ?”
Streaming servers need Constant Bit Rates. HTTP Progressive Download can handle Variable Bit Rates as long as the speed is fast enough that buffering happens faster than playback. VBR is generally better quality so fast action or transitions or motion FX that need more data for quality, can get those bits it needs.
[Tiago Casais] “Also, squeeze doesnt allow using h264 for flv delivery. only for .mov. Any other compression software you “
NO compression program should allow H.264 flv delivery. Adobe engineers recommend against it. Your REALLY should read the preceding posts. I already stated this but you seem to need it repeated.
Flash H.264 is EXTENSION AGNOSTIC. .mp4, mov, .f4v (and many other extensions) ALL WORK IN FLASH.
.flv is for Sorenson Spark (H.263) or On2VP6. Spark is long dead. On2VP6 is still good for Alpha Channel support but is not as efficient (quality at a given data rate) as H.264 on modern computers.
Squeeze uses .f4v for H.264 Flash but .mp4 and .mov will work just as well.
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Indeed i had much better results in the past using h264 than on2vp6. I just didnt know that i could deliver a mov to be integrated in the flash player.
Anyways thank you so much for your detailed explanations, they were very helpful.
cheers to all
Tiago
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If the web guys are not happy with large sizes, be careful of using .mov or .mp4, they tend to be larger, and can be quite larger than a .f4v counterpart. But, from my experience, quality is the trade off as usual.
Drew Jensen
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Data rate and duration roughly equal file size holds true across codecs. There can me differences due to metadata (.mov hinted metadata for example). The distance from my house to your house remains the same whether by car or by train, whether by miles or kilometers. The wrapper itself has little impact on file size.
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