Real World Video Compression

27August2008

Telestream Buys Makers of ScreenFlow

Posted by andybeach under: Announcements; Ramblings.

Telestream buys European streaming-video firm - Sacramento Business Journal:

I’ve mentioned Screenflow here repeatedly - well Telestream, makers of Flipfactory & Episode have now purchase Vara Software who make it, along with 2 other product - Video Cue & Wirecast.

Telestream has done a pretty good job with its purchases (Episode was originally Compression Master, and application by Pop Wire who were also purchased by Telestream) so i’ll be curious to see where this goes.

27August2008

Mac Encoder Shootout Redux

Posted by andybeach under: Research; Software.

note: apologies on the delay in posting this - between the trip to the west coast i’m on, tied with a SQL burp, I lost this post twice before i got it posted!

Matt Jeppsen from FreshDV made the requested that I follow up last weeks encoder shootout with new settings where I attempt to closely match the settings of each application so the results could then be compared.  I took this to heart, though I didn’t attempt to necessarily identically match the settings verbatim.  Here is why - as I noted last time, the tools each obviously run a wide gamut of prices and as one would expect, they also vary a great deal in what they allow you to do to the video.  I didn’t necessarily want to intentionally cripple an application that had taken the time to either create or at least expose to the user a feature that dramatically helped improve the quality or speed of the encode.

So with that in mind, I have rerun my tests with each application.  I have targeted the same approximate data rate and screen resolution for each setting.  However, I have enabled some color/luma settings, specific deinterlace, and crop options where they exist.  Effectively, I created the settings I would ideally want to use for each application to get what isn’t necessarily the best results, but is the right mix of quality, speed of encode, and file size that I decided I like the best.  This may not be quite what Matt was hoping for, but I just don’t believe an apples to apples comparison of these is quite possible, especially having now run the tests twice.

One more note - I didn’t bother running Turbo.264 again in this test.  While its true you can make some custom settings in Turbo, as I began truly exploring this area, I found them to not particularly help improve anything.  At minimum I wanted to crop this content to remove the letterbox introduced in the edit process.  This prove impossible as far as I could tell, which was a bit disappointing.  With that in mind, I saw no benefit in rerunning identical results and therefore disqualified it from this round.  While I found this to be one of the fastest options possible before, the fact that the encode settings were so basic makes it less useful.

Speed Results

As we look at the results, here were the things that stood out for me  - all the times were closer to one another than the last test.  True, Compressor still took the longest, but it definitely closed the gap.  Both it and Episodes times fell and were more consistent this go around (notice neither had an extremely long run as they did before).  Visual Hub’s time did increase, which I expect, though not very much.

Let’s factor one more element into the time results which are not documented in the chart - setup time.  Very quickly I realized I needed to limit the number of attempts I made before deciding on the most optimized settings (in the past, I’ve literally spent whole days just tweaking the settings until I was satisfied).  Since I was under the gun to get these results in before a trip, I limited myself to 3 tests max per application.  Even in limiting to 3 goes, I found the time spent in trying settings (or in some case looking for the settings I wanted to try).  Despite having a huge amount of knobs and dials to play with, I was able to breeze through Episodes settings fairly quick.  I attribute this less to a clean interface (I’ve never accused EP of that!) and more with my experience with the application.  Interface-wise it has changed very little since it was originally launched and having used it quite a bit now, i can run through it very quickly.  The first time you try some of the more advanced settings, it can be quite intimidating, but once you know what to look for (and what to avoid) its fairly smooth sailing.

Visual Hub has very few advanced settings, so this also didnt take that long to run through and in fact it only took 2 tries to hit a file i was happy with.  Compressor however, did take longer to fully get setup.  I haven’t used Compressor a whole bunch professionally since it updated to 3.0 so i’m not sure if things moved since I last used it a great deal, or if the amount of time since I used it caused me to forget some things.  I also got confused by a screen bug I saw on my MacPro that I didn’t see on the MacBook Pro.  Once I cropped the image and set the new correct size and aspect ratio, I was getting a strange stretched version of the image that didn’t match my settings.  After struggling with it for awhile, I discovered that the exported file didn’t actually contain this, so I ignored it (again, this bug never appeared on the MBP).  All in all, I’d say I spent about 45 minutes on Compressor getting setting optimized while both Visual Hub and Episode Pro took about 20-25 minutes.  Most of this time is tweaking settings, as I only encoded 30 second clips for testing.  It was much easier to do this in Compressor and Episode Pro, which allowed me to set in and out points than in Visual Hub, where I actually made a quick reference file of the 30 seconds i wanted to test.

Quality Results

I’ve documented the results less here than I did before, but I did want to show the metal grate that highlighted the different results in the previous test.

In dealing with the interline twitter, I thought the new settings were definitely better in Episode Pro, slightly better in Compressor, and worse in Visual Hub (click through to see the full size screen shot.

In an overall quality comparison, I also thought Episode came out looking best, followed by Visual Hub and Compressor.  There is a sharpness to the image (both video and gfx) in the Episode Pro encode that the other two don’t have (again, check out the full screen to really see the difference).

Conclusions

As I more or less originally stated, if you want full control of the settings -   a high end application is worth the money.  Episode assuredly stands out, though it takes someone with experience and confidence in the settings they are applying to get the results they want.  Compressor, as an essentially free product (as its bundled with Final Cut Studio)  has a number or advanced settings, though the set up wasn’t as intuitive, nor the results as pleasing.  Visual Hub, despite its lack of control, still turned out a fairly decent product, given the price tag though it just could achieve quality i really wanted with the settings i needed.  As was just noted in a meeting I had the other day, a professional compressionist likes to have a lot of tools at his finger tips for encoding and while some may get used more than others, each has their place.

26August2008

site back up

Posted by andybeach under: Ramblings.

big thanks to mjz for helping get my sql problems sorted out and rwvc.tv restored!

21August2008

Yahoo & Intel Seek to Annoy Us More?

Posted by andybeach under: Announcements.

Yahoo& Intel announced a new chip technology geared towards set top boxes and TV’s that enable a “widget channel.” I’m hoping to learn more about this, but all the screen shots displayed so far just look like interactive versions of those lower thid advertisements that have gotten out of control lately (i’m looking at you USA networks).

Being the geek that I am, I love anytime you make my video more interactive, but please for the love of Odin’s Beard (yes I stole that from Buzz Out Loud episode #792) please do not just implement that interactivity in pop up ads and weather trackers - i have enough of both, thank you.

21August2008

More Silverlight Details from NBCOlympics.com

Posted by andybeach under: Links.

NBCOlympics.com Update

Silverlight evangelist Eric Schmidt stopped in at Channel 9 (Microsoft’s Developer Network forum) and recorded an interview about some of the details that went into how Silverlight was used to present the Olympics, including some of the touchy areas like full screen mode and Geo restrictions. He makes a comment about there being contractual reasons about why true full screen wasn’t implemented and I wish he’d have elaborated, but good info regardless.