Best compression for the web

[Daniel Low]

Here’s a good start
https://forums.creativecow.net/readpost/20/862224

1024×576 is PAL square pixel – not 1050×576

Do not reduce your frame rate.
Resize in AE
Export as ProRes if you have it or PhotoJPEG at 90% or uncompressed

[Tiago Casais] “Any commonly known way to reduce noise while preparing the comp to render within AE?(some filter or some other ae feature i should know about?)”

Noise in motion graphics? What do you mean?

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[Tiago Casais]

Hi, and thanks for your answer.

What i meant with the “noise” was if there are particular things you can do ( such as changes in the lights, be carefull with moving backgrounds, dont allow very dark areas, dont use gradients etc etc) so that your video maintains good quality when compressed, thus avoiding pixelation and artifacts in the final compressed version. I cant find any documentation on that.

Should i make the ae render in flv, or avi/mov and then transform to flv in the compressor ?
Why not change the frame rate ? I tried it and the playback seems fine.

note: palwidescreen square changed from 1024 to 1050 in cs4

cheers

[Daniel Low]

[Tiago Casais] “Should i make the ae render in flv, or avi/mov and then transform to flv in the compressor ?”

Make the AE render in AVI or mov – like I said in my previous post.

There is no need to change the frame rate – why would you want to?

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[Drew Jensen]

Q: Reduce frame size to half – should i be doing this in ae or squeeze ?
A: I haven’t used squeeze so I will abstain from answering.

Q: Reduce fps from 25 to 15 or 12 – is it any good at reducing file size maitaining playback?
A: No frame rate reduction. Keep frame rate same as original for best results. File size shouldn’t differ much if reducing.

Q: Since the goal is an flv file, should i be rendering from AE in flv or in an uncompressed format such as AVI or MOV and then convert it to flv within squeeze ?
A: Always keep in uncompressed (or near) format(avi,mov,etc) until putting to final codec,size,etc. NEVER re-compress files ESPECIALLY from FLV to FLV. That would be ridiculously crappy.

Q:Compression always CBR (since its for streaming)?
A: I actually use VBR, and it seems to work best for my particular product and method of delivery. I think most would say there is technically no wrong answer as long as it suits what YOU have and need to happen.

Q: Is a compressor like SSQ the best tool to reduce the file size ?
A: Have not used and will abstain from answering.

Q: And which is the best FLV codec ?
A: Confusion of codec and wrapper. FLV is a wrapper and the codec you usually see is On2 VP6, Sorenson Spark, etc. As far as the best… from what I’ve seen, heard and read, miles may vary so again, what works best for what you need. Try some variations.

Q: Any commonly known way to reduce noise while preparing the comp to render within AE?(some filter or some other ae feature i should know about?)
A: I’m with Daniel… ????

Q: Im getting 7/9mbytes flv files, could this be considered heavy for web streaming playback?
A: Not heavy, but on the upper end. What bitrate are you using? Codec? Audio bitrate? Etc… I could go on for quite a while.

Hope this is of some help.

-Drew
Just a beggar telling another beggar where to find bread.

Drew Jensen

[Craig Seeman]

I’d thought I’d give my slightly different answers and I applaud Drew for posting in a form Q&A which is much easier to handle than the OP.

[Drew Jensen] “Q: Reduce frame size to half – should i be doing this in ae or squeeze ?”

I too can’t tell you which product but what you need to test is which does better scaling. One learns by doing a test.

[Drew Jensen] “Q: Reduce fps from 25 to 15 or 12 – is it any good at reducing file size maitaining playback?”

File size is primarily determined by duration and data rate. I’m not sure where the myth about frame rate (on it’s own) as a method to determine file size began. It can impact quality and sometimes people will also drop data rate but I don’t want to go there unless asked.

[Drew Jensen] “Q: Since the goal is an flv file, should i be rendering from AE in flv or in an uncompressed format such as AVI or MOV and then convert it to flv within squeeze ?”

Actually I’m going to return the volley with a question. Why is the goal FLV?
If the goal is Flash it’s not necessarily FLV at all. Squeeze is a compression tool and it’s going to be more capable for many reasons then AE. AE uncompressed in either AVI or MOV. Then Squeeze.

[Drew Jensen] “Q:Compression always CBR (since its for streaming)?”

Again I return this with a question. Do you know the difference between streaming and progressive download? Generally people should not ask questions based an assumptions which may well be wrong and the resultant answers not relevant.

If it’s from a streaming server than CBR. If it’s HTTP generally VBR is better.

[Drew Jensen] “Q: And which is the best FLV codec ?”

There are basically two FLV codecs. One is based on Spark (H.263) and the other is On2VP6. There’s no reason to use Spark. On2VP6 is only useful when there’s a need for Alpha Channel support or targeting some very very old computers. H.264 is the codec that should be used today and it generally can be wrapped in .f4v, .mp4, .mov (but there are certainly others that work). Flash H.264 support is extension agnostic.

[Drew Jensen] “Q: Any commonly known way to reduce noise while preparing the comp to render within AE?(“

You got noise? That’s usually from live video sources. How you reduce it depends on the processing filters in your compression app. It can range from using Black Restore to Noise Reduction and sometimes Gamma can even help because it depends on where the noise is.

[Drew Jensen] “Q: Im getting 7/9mbytes flv files, could this be considered heavy for web streaming playback?”

Incomplete question. Are those file sizes or data rates? 9 mega bytes a second! 9 mega bits a second is extremely high. 9 mega bytes a second wouldn’t even work on a Blu-ray disc. That’s like 72 mega bits a second.

[Drew Jensen]

“File size is primarily determined by duration and data rate. I’m not sure where the myth about frame rate (on it’s own) as a method to determine file size began. It can impact quality and sometimes people will also drop data rate but I don’t want to go there unless asked.”

I’ve heard, again heard that it may differ slightly. By slightly I mean we’re talking about overall size of a few KB because of amount of keyframes. I don’t know if I buy it or not. But like you said, it’s the duration and data rate.

Drew Jensen

[Craig Seeman]

The story behind the misconception of frame rate vs size as I know it.

If you decrease the frame rate you have more bits per frame. At that point you haven’t changed the file size but you’ve increased the quality of each frame and the cost of temporal motion.

If your goal is not to increase quality but to decrease size, with a lower frame rate you can lower the bit rate to maintain quality. The problem is that it’s not a proportional decrease in bit rate.

If you’ve cut the frame rate in half you’ve also just increased the amount of change from frame to frame. If it’s talking heads it’s still not too much change. If it’s something with more action there’s a heck of a lot more change. The result is that depending on the content, you may not really be able to lower the bit rate that much.

Again the actual change in data rate you can get away with is dependent on content.

A vaguely remember hearing in a past life that you could lower the data rate from about 10% to about 30% (depending on the content) to maintain the same quality when cutting the frame rate in half.

This was critical back in the days when people would view video with dial-up connections and/or servers had very very very limited space for files.

Some compression apps, depending on the codec and the app, will do the “maintaining” of quality for you so if you were to lower the frame rate and target a quality settings it would lower the data rate (and hence the file size) for you.

So the short answer is you might save 10%-30% in file size if you were to maintain frame quality when cutting the frame rate in half.

You might even find a few local news sites still doing this because they serve a rural or low income (dial-up) region or they have such high volumes of material (most of it talking head) and want to save server space. I’ve found that the last few of those sites I personally know of have changed that around two years ago.

For various reasons most sites have no interest in serving those still on dial up (certainly worth a brief separate topic). These days even people on slower broadband can handle full frame rates at reasonable frame sizes.

For example, typical live stream video on Livestream’s free live service might be 448×336 25fps at 500kbps and that looks fine. A typical 480×360 YouTube video is running at full frame rate and looks fine as well.

Except in the most extreme circumstances in which you must reach dial up users and have limited server space, there’s really no reason to drop the frame rate. There’s very little file size to save and the temporal motion loss is just not worth it.

[Daniel Low]

[Drew Jensen] “Q:Compression always CBR (since its for streaming)?
A: I actually use VBR, and it seems to work best for my particular product and method of delivery. I think most would say there is technically no wrong answer as long as it suits what YOU have and need to happen.”

Are you sure you’re talking about streaming, not progressive download? – RTSP requires CBR, VBR would almost certain fail to deliver.

[Drew Jensen] “Q: Im getting 7/9mbytes flv files, could this be considered heavy for web streaming playback?
A: Not heavy, but on the upper end. What bitrate are you using? Codec? Audio bitrate? Etc… I could go on for quite a while.”

Utter confusion here! ‘7-9Mbytes’ refers to a file size (without a per second or /s at the end). File size has no relevance if the file is being streamed, that is if you are using the word ‘streaming’ in the true sense of the terminology. If the file is being delivered as a progressive download otherwise known as HTTP stream then it has a relevance.
As such, if it is a 9MB file delivered over HTTP then it is a very low demand delivery. If it’s a 9MB per second file delivered of RTSP – true streaming then it’s an impossibly heavy delivery 9MB/s = 72Mbits per second.

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[Daniel Low]

Dropping the frame rate was also a requirement when the playback device simply couldn’t cope with a full frame rate due to lack of processor power. This is simply not the case anymore.

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[Drew Jensen]

My bad, I forgot to mention that important aspect. Yeah, I use it for progressive. As for the second part, I assumed the size, which I have to teach myself constantly that that is not a good thing to do.

Drew Jensen