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Exasperated with Transcoding - What's the Secret?

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Andres Lopez-Ovejero
Exasperated with Transcoding - What's the Secret?
on Mar 29, 2011 at 2:00:07 pm

Ok, I'm not a video compression novice and i spend lot of time stalking these forums when i need help. but...

I was editing a piece for those kiosks in Times Sq for a client. Motion graphics and some time lapse photos. simple. put it together in After Effects. tried to output to H.264. total blocky garbage. ok fine. i don't really know the Adobe transcoder so well, so I output lossless and then convert to H.264 in Compressor. Spent time looking for best settings mix, outputted numerous versions. got a little bit of artifacting around the moving graphics but not too bad (even though the graphics came from Vector based files that shouldn't degrade) some color degradation, etc. then when i go to upload to the FTP for delivery i take a look at some of the other guys' stuff. totally pristine 30 sec segments, 1080p, under 20MB. motion graphics and video mix. We have the same datarate (5Mbps), same resolution, same framerate (30), same codec. what is the !#$% secret sauce for H.264 compression.

I almost created a problem because i spent so many hours (more like days) futzing around with the compression I delayed delivery a bit.

Look i know there is no one right set of settings, for anything. But is there some book, anything that I can use to study up on the methodology of compression so I can arm myself with some tools to apply in these situations. I mean I can't even make a standard SD MPG2 DVD look good unless I spend 36-48 transcoding it (and even then my text is all jagged). I also believe that I have all the right software, in addition to Compressor, i use Episode 6 and the Adobe Media Encoder. And i know the programs, for example, I set up Compressor clusters to distribute compression tasks across my network. I feel like I know what i'm doing and should be able to figure out the solutions but i still find myself in the office to 3 am futzing around with check boxes and still sometimes delivering what i feel is a substandard product.

I can post screen shots of the segments in question if it will help.

Any suggestions?


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Craig Seeman
Re: Exasperated with Transcoding - What's the Secret?
on Mar 29, 2011 at 2:59:16 pm

http://store.creativecow.net/p/64/internet_killed_the_video_star

Also Philip Hodgetts had a great eBook called Simple Encoding Recipes for the Web which seems impossible to find (apparently he's no longer selling it on his site) but if you Google it you might find some sites have archived it. You'd want the 2009 update, not the 2007 edition.

You really need to know your source and your target. You need to know how to analyze. It's never pushing buttons because there are many types of sources and the targets vary.

You need to know fundamentals such as deinterlacing when needed.
Data Rate times duration equals file size.
Bits per pixel impact quality. Frame size, frame rate, data rate in relation to bits per pixel.
H.264 use in various players.
The variety of H.264 implementations. They are not the same. Apple tends to be the worst. MainConcept is good. X264 can be good too. There are others as well.
CBR vs VBR and one pass, two pass, multi pass encoding.



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Brad Elliott
Re: Exasperated with Transcoding - What's the Secret?
on Mar 29, 2011 at 4:23:21 pm

Just out of curiosity what are the H264 files playing back on that requires 1080p?

Have you tried exporting ProRes422HQ from AE and then using the Compressor preset for H264?

The problem is most likely related to what is coming out of AE.

Are you able to export anything that looks correct out of AE?
Animation, Photo JPG, etc?


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Andres Lopez-Ovejero
Re: Exasperated with Transcoding - What's the Secret?
on Apr 1, 2011 at 7:58:00 pm

Do you know the Times Sq area? An organization called CEMUSA,they outfitted newsstands with 2X2 55" LCDS on the back (street facing), and one vertical 65" on each of the sidewalk facing sides.

These silly things:
http://en.ooh-tv.com/2010/09/14/usa-first-cemusa-digital-newsstand-installe...

Everything coming out of AE looks great but i'm sure what's happening is that i'm robbing the encoder of the ability to see what the separate elements are that make up the motion graphics. So for example AE knows when a graphic is a vector and can wait till the last second to render and encode it. When I output lossless and THEN encode, the encoder only sees a single image and encodes it as such. This in my mind is part of what is leading to the artifacting (esp. around edges). I would imagine it's like the difference between making a collage and then taking a picture of the collage once you've made it.

As I mentioned i outputted lossless, zero compression, no audio. 5.6GB for 30 secs. I couldn't even play it smoothly it was so large. do you think going ProRess in that situation would be a better option than lossless? I have not tried that route.

And yes i can make things look good out of AE sometimes. usually it's in DVCProHD is where i get good results. it's just that compression control options seem so LIMITED in AE (even compared to Adobe Media Encoder). So I can make things look good in AE, it's just that I can make them look a lot better elsewhere.


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Craig Seeman
Re: Exasperated with Transcoding - What's the Secret?
on Apr 1, 2011 at 8:24:50 pm

I'm not sure your assumption are correct about AE.

You need to understand the requirements for the specific playback device being used and encode appropriately. Instead of Animation Lossless you might consider outputting Uncompressed 4:2:2 8 bit (I'm not sure 10 bit would help in this case) or Apple ProRes HQ. You'd then target based on the capacity of the targeted device's playback ability.

I've output for digital signage (not animated source though) and H.264 high data rate was fine.



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Jason Brown
Re: Exasperated with Transcoding - What's the Secret?
on Mar 29, 2011 at 6:57:09 pm

I was in the same boat (sort-of)...I needed to do multiple tests and work to find the best quality for the content at the lowest file sizes. I can tell you that the 400 dollar CompressHD card revolutionized my life! Besides creating good looking transcodes...you can make several test files in minutes. So you can take their presets and if the file size is too large, just tweak it...then you can check the new file you create. h264 was a thorn in my side for many years...until I got this card, you'll save 400 dollars worth of time in one week if you do a lot of h264 encoding.

As far as your specific issues, I've found what works for me by doing multiple encodes and taking notes of my settings for each one and determining what was working for what type of content. I do a lot of different stuff, soft - doc style, long dissolves, moves on photos...all the way to people standing at a podium for and hour. I can tell you that extending your GOP and reducing the bit-rate can save you a ton of file size on a podium piece, but you'll hate the way it looks on more complicated stuff. You have to have sets of encoding settings to work with different content.

-Jason


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Craig Seeman
Re: Exasperated with Transcoding - What's the Secret?
on Mar 29, 2011 at 7:05:15 pm

Relating to Matrox CompressHD this might be worth a view
Review
http://library.creativecow.net/articles/seeman_craig/matrox_compressHD.php
Matrox H.264 Encoding Webinar
http://library.creativecow.net/scartozzi_francesco/h264-matrox-webinar/1

BTW I obviously use Matrox CompressHD (MXO2 with MAX as well) and it's blazing fast and the quality is excellent. The codec controls have become very deep and sophisticated since I wrote that review. It might be time to do an updated version on the new features.



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Andres Lopez-Ovejero
Re: Exasperated with Transcoding - What's the Secret?
on Apr 1, 2011 at 7:39:56 pm

@Craig Sheeman I did a search and not only pulled up the 2009 version but the 2010 as well. However it's hosted on the Telestream site and is specifically for Episode, was that the one that you were referring to? It looks like a really great, straight forward overview of standards, and best practices. Looking forward to reading it.

http://www.telestream.net/pdfs/user-guides/Simple-Encoding-Recipes-2010.pdf

and i'll check out the Compress HD review.


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Craig Seeman
Re: Exasperated with Transcoding - What's the Secret?
on Apr 1, 2011 at 8:17:50 pm

There's another version which has information for other apps as well such as Compressor, Squeeze and Adobe Media Encoder. I'm not sure why Philip Hodgetts pulled it.



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Andres Lopez-Ovejero
Re: Exasperated with Transcoding - What's the Secret?
on Apr 1, 2011 at 8:04:50 pm

@ Jason Thanks for the tip about the GOP. i was under the impression that extending the GOP (and leaving it open) simply allowed the file to be compressed more and had no significant impact on the look. most of what i need to do MPEG 2 compression for is sit down interview DVDs. any suggestions on settings?

and the CompressHD. I don't know if I do enough H.264 work to justify the speed, I don't have a slot in the Mac Pro, and quite frankly, I resent that I have to pay more money for something I feel like I should be able to do in software.


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Craig Seeman
Re: Exasperated with Transcoding - What's the Secret?
on Apr 1, 2011 at 8:37:20 pm

You MUST use closed GOP for DVD for "cue points."

[Andres Lopez-Ovejero] "and the CompressHD. I don't know if I do enough H.264 work to justify the speed

It's rare I hear anyone saying don't do enough H.264 work to justify speed. H.264 is ubiquitous. True non for DVD but it's used in Blu-ray and I've even used it for broadcast delivery on occasion. Some VOD situations call for H.264 Transport Streams as well.

[Andres Lopez-Ovejero] "quite frankly, I resent that I have to pay more money for something I feel like I should be able to do in software."

If speeds important you'll be a long way off on that. "Software" ALWAYS involves hardware. Matrox MAX even beats Virtual Cluster encoding on multicore Macs. You want faster you can get it if set up a multicomputer cluster. Episode Engine running on several computer (and many thousands of dollars for the software and the computers) is fast. Your computer is hardware. Encoding always involves hardware. It all depends on what you want to tie up to do the encode.



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Jason Brown
Re: Exasperated with Transcoding - What's the Secret?
on Apr 1, 2011 at 9:23:31 pm

Good points Craig, it reminds me of something I heard Aahron (sp?) say a long time ago--u can use a shoe to hammer a nail, but a hammer does it faster and better. Right tool for right job.

Craig, r u gonna be at nab? I'd like to meet u, I'm a fan! :)


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Jeff Greenberg
Re: Exasperated with Transcoding - What's the Secret?
on Mar 31, 2011 at 1:47:15 am

Sure. Can you get one of the [Andres Lopez-Ovejero] " of the other guys' stuff"?

Drop the h.264 into the Compressor Preset window - you'll get their exact formula.

I suspect that something else is going on; for example, using a cluster actually worsens compression because the 'VBR' part is limited to the segment each cluster gets.

First try their settings and then come back and report what happened (and what they were!)

Best,

Jeff G

Apple Master Trainer | Avid Cert. Instructor DS/MC | Adobe Cert. Instructor
------------
You should follow me (filmgeek) on twitter. I promise to be nice.
Come See me speak at NAB!
Compressor Essentials from Lynda.com
(older but still good) Marquee, Media Composer (3.5) and Basic/Advanced Color DVDs (1.0) from Vasst.com
Contact me through my Website


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Andres Lopez-Ovejero
Re: Exasperated with Transcoding - What's the Secret?
on Apr 1, 2011 at 8:45:18 pm

The first two are theirs

http://www.flickr.com/photos/andres_mlo/sets/72157626407552440/

it resized the images a bit, what is a better image host?

So you see, I have poor color reproduction, some haloing around the letters and artifacting around the 'museum of arts and design' logo element.

the VBR thing is something i will keep in mind, but in this situation, despite clustering I had a set data rate that stuck to.

besides clearly higher production values, it looks like the other company set key frames at 15 bumped the data rate up to 5259 (??) and only did a single pass (?). also they put it at 23.98 FPS which we were specifically asked not to do, but that would technically increase their per frame data rate. although that can't be the answer.

I'll try running the settings over the weekend.


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Craig Seeman
Re: Exasperated with Transcoding - What's the Secret?
on Apr 1, 2011 at 8:56:19 pm

[Andres Lopez-Ovejero] "what is a better image host?"

You can post images directly to the COW.




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Andres Lopez-Ovejero
Re: Exasperated with Transcoding - What's the Secret?
on Apr 2, 2011 at 12:04:33 am

thanks. unfortunately the images were over 500KB per. so it wouldn't allow me to upload them. my mistake, I should have mentioned that.


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Jeff Greenberg
Re: Exasperated with Transcoding - What's the Secret?
on Apr 2, 2011 at 1:42:46 am

[Andres Lopez-Ovejero] "it resized the images a bit, what is a better image host?
"

A file host - not an image host; dropbox, mobileme, yousend it. Something that leaves the file alone.


[Andres Lopez-Ovejero] "besides clearly higher production values, it looks like the other company set key frames at 15 bumped the data rate up to 5259 (??) and only did a single pass (?). also they put it at 23.98 FPS which we were specifically asked not to do, but that would technically increase their per frame data rate. although that can't be the answer."

Each of these, EACH, can make a difference.
HD? h.264 at 5mb/s ? Yup, that'll work. Single pass? Strange, but possible. 23.98? Well, if they shot it that way...it means every frame got 20% more information (than if they used the same exact settings at 29.97).
Production values? Well, a soft DOF means easier compression.

Best,

Jeff G

Apple Master Trainer | Avid Cert. Instructor DS/MC | Adobe Cert. Instructor
------------
You should follow me (filmgeek) on twitter. I promise to be nice.
Come See me speak at NAB!
Compressor Essentials from Lynda.com
(older but still good) Marquee, Media Composer (3.5) and Basic/Advanced Color DVDs (1.0) from Vasst.com
Contact me through my Website


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Craig Seeman
Re: Exasperated with Transcoding - What's the Secret?
on Apr 1, 2011 at 8:51:53 pm

[Jeff Greenberg] "Drop the h.264 into the Compressor Preset window - you'll get their exact formula."

Or for more detail VideoSpec
http://www.apple.com/downloads/macosx/video/videospec.html



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Eve Kinizo
Re: Exasperated with Transcoding - What's the Secret?
on Aug 9, 2011 at 8:04:28 pm

HI Craig,
Would you say that Internet killed the video star covers all types of compression techniques not just for the web?

also, when you call it for the "web" -do you only refer to small size files like youtube ,vimeo etc (although they allow HD hi res as well ) or would you say it also deals with specs for any Digital file to be launched online on any platform ,any size and codec?

thanks !

Eve


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Craig Seeman
Re: Exasperated with Transcoding - What's the Secret?
on Aug 9, 2011 at 8:44:48 pm

Web. Web can be all the way to 1080p these days. Basically web as opposed to Optical Disc (DVD/Blu-ray) or Broadcast delivery (Program and Transport streams). Web can include videos posted by broadcast channels though.

Since then a great book has come out, also on web. Highly recommended by me.
http://www.streaminglearningcenter.com/video-compression-for-flash-apple-de...



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