[videoblogging] MPEG-4 settings

2005-09-08 Thread JD Lasica 
Today I spent a little while experimenting with MPEG-4 settings.
Because some people prefer MPEG4 to QuickTime, I've been hoping to do
more of my video in mp4, but I've never been pleased with the default
settings.

So, I thought I'd ask the wise people on this list for some advice or
pointers for MPEG-4 compression settings for publishing a video for
display on Ourmedia. (And, yes, I know all about Michael Verdi's PDF
primer on Video compression with 3iv ...
http://www.ourmedia.org/node/42835).

(1) The application.

I generally edit video on my Mac (OS 10.3.9) with imovie HD 5.0.2. I
also have a Sony Vaio desktop PC. So I'm open to using a different
application (I have Final Cut Pro, for eg, but haven't had time to
learn it), if that would be advisable. But I think I'm probably fine
with what I've got.

(2) The settings.

When I choose Share (to encode the video), under Options/MP4 Export
settings, I see ...

Video:
On a hunch, I chose MPEG-4 Improved (rather than MPEG-4 Basic)
Data rata 256 kbps (this was pre-entered)
Image Size: 320x240 QVGA
Frame rate: 12 (i use 15 when there's more movement in the video)
Key frame: every 75 frames (used this from a prior tutorial from Ryan)

Audio:
Audio format: AAC-LC (Music) (that's the only choice given for MPEG-4 Improved)
Date rate: see below
Channels: Mono/Stereo
Output sample rate: 44.1 kHz
Encoding qality: best (upped it from better)

Streaming:
Enable streaming? yes
maximum packe size: 1450 bytes
maximum packet duration: 100 ms
optimize for server? yes

I encoded an eight-minute video at 15fps, 64 kbps audio, mono, and it
came in at 27.8 mb:

http://www.archive.org/download/JDLasicaRUSiriusonpodcasting/RU_Sirius.mp4

I was happy with the video quality but unhappy with the audio.

So, I tried again, at 12fps, 96kbps audio, mono, and it came in at
40.8 mb. I was still happy with the video quality but still unhappy
with the audio.

I adjusted it to 128 kbps audio, stereo, and it came in at 44 mb. I
was happy with the video and audio quality. And I'm happy at how fast
the video starts playing. Here it is:

http://ia300112.us.archive.org/0/items/JDLasicaMondoGlobosRUSiriusonthepodcastingphenomenon/RU_Sirius_new.mp4

But I'm wondering if I should play with any of the other settings
above to reduce the file size without compromising audio or video in
any significant way and without reducing the window size. For example,
I need a primer on things like MPEG-4 Improved vs MPEG-4 Basic, data
rate, key frame, etc.

We're creating a knowledge base/learning center on Ourmedia, so I'm
hoping that any information shared on this list about this topic can
be shared on Ourmedia as well.

thanks!
jd
exec director, Ourmedia


 Yahoo! Groups Sponsor ~-- 
Fair play? Video games influencing politics. Click and talk back!
http://us.click.yahoo.com/T8sf5C/tzNLAA/TtwFAA/lBLqlB/TM
~- 

 
Yahoo! Groups Links

* To visit your group on the web, go to:
http://groups.yahoo.com/group/videoblogging/

* To unsubscribe from this group, send an email to:
[EMAIL PROTECTED]

* Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/

Re: [videoblogging] MPEG-4 settings

2005-09-08 Thread Adrian Miles 
around the 8/9/05 JD Lasica mentioned about [videoblogging] MPEG-4 
settings that:
Streaming:
Enable streaming? yes
maximum packe size: 1450 bytes
maximum packet duration: 100 ms
optimize for server? yes

if you are not delivering via RTSP turn this OFF. it adds a hint 
track to your mpeg4 file which will significantly add to final file 
size and is *useless* for http delivery :-)
-- 
cheers
Adrian Miles

hypertext.RMIT
URL:http://hypertext.rmit.edu.au/vlog


 Yahoo! Groups Sponsor ~-- 
Most low income households are not online. Help bridge the digital divide today!
http://us.click.yahoo.com/cd_AJB/QnQLAA/TtwFAA/lBLqlB/TM
~- 

 
Yahoo! Groups Links

* To visit your group on the web, go to:
http://groups.yahoo.com/group/videoblogging/

* To unsubscribe from this group, send an email to:
[EMAIL PROTECTED]

* Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/

Re: [videoblogging] MPEG-4 settings

2005-09-08 Thread Adrian Miles 
around the 8/9/05 JD Lasica mentioned about [videoblogging] MPEG-4 
settings that:
But I'm wondering if I should play with any of the other settings
above to reduce the file size without compromising audio or video in
any significant way and without reducing the window size. For example,
I need a primer on things like MPEG-4 Improved vs MPEG-4 Basic, data
rate, key frame, etc.

mpeg4 improved better. key frames. natural keyframes usually better 
than arbitrary setting. the best modern codecs work ouit for 
themselves where keyframes ought to go. if you add keyframes a lot 
then a) they add a lot to final size for *no* change i quality 
(talking head for 15 seconds, at 15ps, thats 225 frames, a decent 
codec needs one keyframe at start and that's it, so if you have one 
every 5 seconds (75 frames) you've added 2 additional keyframes that 
add a lot to file size but virtually nothing to perceptible quality.

finally I'd only be outputting audio at 44.1 if you are a) making 
high quality music or b) sound works and this is *very* important to 
you, otherwise you can drop that a lot, particularly if it is only 
voice.
-- 
cheers
Adrian Miles

hypertext.RMIT
URL:http://hypertext.rmit.edu.au/vlog


 Yahoo! Groups Sponsor ~-- 
Fair play? Video games influencing politics. Click and talk back!
http://us.click.yahoo.com/T8sf5C/tzNLAA/TtwFAA/lBLqlB/TM
~- 

 
Yahoo! Groups Links

* To visit your group on the web, go to:
http://groups.yahoo.com/group/videoblogging/

* To unsubscribe from this group, send an email to:
[EMAIL PROTECTED]

* Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/