Zarax
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Location: Italy
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 Posted: Thu Jun 16, 2005 7:49 pm Post subject: MSUN Newsletter – 06/2005 |
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| Code: | MSUN Newsletter – 06/2005
Welcome to the June MSUN newsletter!
As you may have noticed MSUN experienced some problems last month with the transfer which lead to downtime and greatly slowed down our work there, reason why there wasn’t a May edition.
This month we heavily focused on Windows Media Encoding, so our WME users will find something useful or maybe some stuff to be arguing with ;-)
1) Mastering Windows Media Encoder: Optimizing your settings, by Zarax
2) Windows Media Tips&Tricks, by McoreD
- Mastering Windows Media Encoder: Optimizing your settings
Hello everybody, this month we will focus on how to get the best results by optimizing your encoder settings for your different scenarios based on real life needs.
In the final part of this article we will also discuss some unorthodox low bit rate optimization for the special files that needs to squeeze the quality to the last bit.
- DVD and CD: The realms of high bit rate encoding
Encoding at high bit rates is often seen as an easy, piecemeal task.
Most scenarios are in fact quite straightforward, with usually enough bit rate to leave room to personal tastes.
Depending on the content duration CD size encodings typically range between 650 and 1200kbps, allowing DVD or near DVD quality, while DVD's size easily allows HiDef with a 4-10Mbps range.
Most encodings here are done with dual pass Variable Bit Rate and leaving the resolution close to the source size (around 720x576 for PAL and 704x576 for NTSC) with slight scaling down in some cases for the 650-800kbps range, usually to 640x480.
Audio is where personal tastes play their role.
While many retain the 128kbps setting from the old MP3 days, your ears are the best judge here.
My personal criteria is to use around 15% of the total bit rate with WMA STD (usually 96kbps), switching to the professional codec if there is enough space to allow at least 128kbps in stereo mode.
For higher bit rates, WMA Pro at 192kbps or more will do an excellent job with 5.1 (I’d go at 256kbps for 7.1) surround audio, giving you an amazingly good quality.
Finally, as WMV home players are reaching the market (and taking their sweet time in the process) it may be a sensible choice to use the peak VBR setting in WME as it will avoid stuttering due to excessive load in high motion scenes (just remember it's drive speed*150*8 for CD and around drive speed*1300*8 on DVD)... This is also a possible choice for lower bit rate settings as it will sacrifice some high motion quality to benefit the overall movie and also if you plan to play the content on older machines as requisites goes up with higher speeds.
- Broadband encoding techniques
For broadband encoding we mean the generic broadband bandwidths, ranging from 256kbps to 640 although the later ones are much faster and can be counted in the first category.
The average settings here are a resolution around 320x240 (but for the higher bit rates you may want to try 480x320) with an audio bit rate between 32 and 64kbps (the 15% rule works quite well here too).
As this kind of content is meant to be streaming media Constant Bit Rate encoding is the choice, with two pass encoding if you aren't using a live source.
- ISDN and medium bandwidth scenarios
While ISDN is being phased out, it's still worth of some attention as many businesses still uses it for their internal network (plus not everyone can afford to stream broadband content).
With 64 and 128kbps settings available, bit rate here starts to be quite scarce for video, so unless you're displaying very low motion content visual quality becomes secondary concern, while smoothness starts to be something to manage in order to avoid frame drops.
Resolution can be either 160x120 at 64kbps or 240x180 at 128kbps.
It might also be useful to reduce the frame rate a bit in order to preserve some visual crispness, settling for 15fps at 64kbps won't hurt with smoothness between 60 and 80.
Audio management also becomes much more important here.
As video quality becomes insufficient to effectively deliver the message it's important to focus on having at least a decent listening experience, so 20/25% of bit rate should be used for audio, meaning 32kbps at the higher setting while the lower one should really settle for WMA voice at 16kbps.
Using these bit rates also means that you have to be selective on the kind of content you want to publish: high motion, rich sound sources are most likely to give you very poor results here, while "simpler" content will degrade in a more acceptable way.
Again, as this kind of content is meant to be streaming media Constant Bit Rate encoding is the choice, with two pass encoding if you aren't using a live source.
- Dial-up: critical bandwidth balancing to maximize audience
Having video on dial-up is still a big challenge as you will have to work with really scarce resources, meaning you will have to put the focus on audio rather than video, and this is going to be voice audio unless you are forced to use more complex sources, leading usually to horrible results.
Dial-up lines, despite being "56k" most of the time can't effectively use more than 40kbps, reducing the already anemic bandwidth.
160x120 is going to be your resolution unless you're going to make slide-show like content, in that case you might obtain some extra room (but not more than 192x144 and this should already belong to low ISDN realm) using low frame rates (12-15fps).
WMA voice is going to be your only real choice, using 10-12kbps, while video smoothness shouldn't be more than 60 and it's likely to experience some (but acceptable in most cases) frame dropping.
- Extreme low band optimization tips
If you need this section you are either experiencing very though content on low to medium bandwidth or trying to impress someone boasting you can stream video under 28kbps (you can, but if you pretend to get decent quality here you're gonna need medical assistance) for the low-band nazis and GPRS videophones.
If all else fails and your content has a lower motion in the beginning you can try something quite unorthodox: use VBR.
Before raising your eyebrows, this method isn't guaranteed to work and gives its best on short, discontinuous motion content.
Peak VBR can give you some extra bits thanks to the fact WMP can use the extra bandwidth made available in low motion scenes, giving more where it's required.
This way you can "overrate" your bandwidth, giving up to 10% gain on short clips.
This means you will be able to give up to 3 extra kbps at 28k, with proportionally more or less depending on your available bandwidth.
If that is still not enough you can either try to use very low fps (around 5, virtually a slideshow) or make your life easier and opt for download&play later.
- Windows Media Tips&Tricks
What’s New in MSUN Guides and Tutorials?
Converting FLV (Flash Video) to (Windows Media Video) WMV
You might have come across some websites that have Flash Video which play in your browser. They get stored in your browser cache. If you are using Internet Explorer, they will be in your Temporary Internet Files folder.
If you ever wanted to know how to convert these Flash Video content to another format especially to Windows Media Video, here is how.
http://microsoftusernetwork.com/mcored/knowledgebase/kb-flvtowmv.html
Converting DTS to Windows Media Audio 9 Professional
As you might have seen in the forum converting DTS audio to any other format was not an easy task. Converting to Windows Media Audio with 5.1 audio was even more challenging. With a new freeware source solution called tranzcode this is now easy as converting AC3 to WMA 9 Professional.
http://microsoftusernetwork.com/mcored/knowledgebase/dtstowma9pro
What’s New in MSUN Tools and Apps?
DVD2WMV Assistant 1.1.7
DVD2WMV Tools is updated to version 1.1. A name change was required to avoid confusion with versioning of DVD2WMV Tools package. AviSynth Script Generator is now called DVD2WMV Assistant.
DVD2WMV Tools 1.4.2
This version adds DVD2WMV Assistant 1.1.0 and updates existing utilities: DGIndex to version 1.4.0 Beta 2 and WM9 Bitrate Calculator to version 2.2.
Donald Graft’s DGIndex now supports MPEG1 streams. This means you can use DGIndex to create a D2V project with several MPEG1 files as the source. Now you will be able to create an AviSynth script to load these MPEG1 files and convert them to WMV using Windows Media Encoder.
A very old calculator error for DVDR file sizes was fixed in WM9 Bitrate Calculator version 2.2.2.3. The error affected every version since 1.3.
Since a new shortcut name is added, it is recommended to uninstall older versions of DVD2WMV Tools to avoid creating duplicate shortcuts in your start menu.
http://www.microsoftusernetwork.com/mcored/downloads/dvd2wmvtools.zip
That’s all for this month, as always we wait for your feedback at www.microsoftusernetwork.com/forum
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