Re: BBQ Videos

From: jon@dakota-truck.net
Date: Wed Apr 13 2005 - 12:49:18 EDT


Walt@walt-n-ingrid.com wrote:
[...]
: Yea, but I only captured the clips with my truck so far (and two clips of me
: pulling Mike's Ram Charger) BTW, I got the tape Jon, Thanks. I'm still working
: on finding a decent .mpg to .wmv converter because the file sizes are coming
: out larger than I would like and don't seem to stream well. This is really my
: first attempt at playing with video so I'm still trying to figure it out. I'm
: hoping that if I can convert them to .WMV I can get the file sizes down some
: and they'll stream better.

: This is what I captured so far http://www.walt-n-ingrid.com/video.html
: (Bandwidth Alert, if your on dial-up, look at the file size before you attempt
: to watch one)

  Hi Walt,

  Looks like you're using 320x240, I think that's a good size for
these videos. 640x480 would be overkill, and would take up a lot
more disk space.

  You're actually getting a heck of a lot better compression than
I was on the videos (what are you using?) I used a freeware utility
I found called avi2mpg.

  As far as the streaming goes, I wasn't sure if you meant that
they don't stream well when playing from a web page or even when
they are downloaded and played from disk. I ran into a problem with
some of my videos in the past where they would start to "chunk", for
lack of a better term. (The video would drop frames and it looked
more like a stop motion animation than video.) This seemed to happen
in sectinos of the clip which had more action; it wasn't so bad
when things weren't moving around or the camera wasn't panning. I
found that I could eliminate this problem by increasing the bitrate.
Unfortunately, this also increased the file sizes. My normal procedure
was to encode all the videos at my "usual" compression level/bitrate,
then watch them and the ones that were stuttering, I just kept
increasing the bitrate until they were OK.

  I don't think I've encoded any Daktoberfest/BBQ vids for a
couple of years now, but since that time I have started to play
around with DivX a little bit, and if I were going to do it
again, that's what I would use. DivX is generally what is used to
encode full length feature films to a 600-700MB file size, while
still maintaining very good picture quality. (VHS or better)
So it might be worth your while to take a look at that. Depending
on what software you are using, you may be able to just download the
codec and go to town. You can find DivX info, download codecs,
etc. from http://www.divx.com.

  I noticed you mentioned looking for a .mpg to .wmv converter;
I'm guessing this means you are capturing directly into your
software and then exporting as MPEG? If you try to convert
the MPEG to WMV, you may notice some loss in quality. (Wether
whatever loss there might be is acceptable or not would be your
call.) In general, its recommended to go directly from the
original source to the final product in one (compression) step.
So in your case, wanting to do WMV, the best case would be if your
software could do the capture and export as WMV instead of saving
as MPEG and then converting it. If that is not an option, what you
can do is to capture and then save the result as an uncompressed AVI.
That's how I did the videos in the past - saved to uncompressed AVI,
then ran the avi2mpg converter directly on the full quality AVIs
to generate the final mpegs.

  Anyway, I think I said everything I meant to. :-) If you're
looking for smaller file sizes, I would definitely give DivX a
shot. If your software can't export to DivX, there are free
programs available which will work with the codec, such as
VirtualDub. So, at the very least, you can capture to full
quality, uncompressed AVI, then load those up in VirtualDub and
export to DivX. One catch with encoding as DivX is that anyone
who wants to watch them will need to install the DivX codec, but
its free and available for Windows and Mac from www.divx.com.

  Oh, one other thing on file sizes, make sure the audio is
being compressed also, and the settings on this can be pretty
low; it doesn't need to be CD quality - probably 8 bit 22kHz
will be more than adequate. Capturing as mono might save some
space too, since this is camcorder footage, there probably isn't
any advantage to using stereo. (I think the settings you
are using in your files were 44kHz, 16 bit, and it looks like
they were already in mono.) You should also make sure your
software is compressing the audio. Audio can take up a surprising
amount of room if it isn't compressed.

  I'm certainly no expert, but let me know if I can be of
any assistance. I wanted to try and find a video file to
do a quick test on, but the only uncompressed AVI I could
find was a 13 second capture of my cuda during the cam
break in. Unfortunately, there's almost no movement in the
file so its proably not a great indicator. Anyway, using
DivX and with MP3 audio of 24kbps, 22kHz, mono, the file
size came out to 240K (320x240). I also tried it out on
your 14 second dakclip01.mpg, (originally 3.67MB), it came
out to 730KB. (Just as an aside about audio compression, this
same file with DivX compression on the video but re-using the
audio as-is from your file came out to 2MB. So the audio is
probably what is inflating your file sizes.) I also tried it
out on your dakclip04.mpg (originally 50MB) and it came out to
7.4MB. If you want to check them out, I stuck them at
http://jonsteiger.com/temp/walt

  If you would like me to convert some more samples for you
at different settings or something, just let me know. Or,
if you don't want to mess with the DivX stuff or for some reason
it isn't compatible with your setup, I'd be glad to convert
your vids to DivX for you. Its really easy, once I get the
settings where I want in VirtualDub, I can just dump them
into the program and it'll churn through them all in batch
mode. So, it wouldn't be much trouble.

 TTYL!

-- 
                                          -Jon-

.-- Jon Steiger ---- jon@dakota-truck.net or jon@jonsteiger.com --. | 1970 Barracuda - 1990 Dakota 'vert - 1992 Ram 4x4 - 1996 Dakota | | 1996 Intruder 1400 - 1996 Kolb FireFly - 2001 Ram QC 3500 CTD | `------------------------------------ http://www.jonsteiger.com --'



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