Re: What is so special about AVI?
- From: Andy <nomail@xxxxxxxxxx>
- Date: Sat, 22 Apr 2006 20:43:02 +0100
Richard thank you for your useful reply. You made many points. They
seem to center upon not having enough info on quite what codecs are used
by the AVI and those which are on my PC.
In addition you mention that my replay codecs may be a factor.
You asked some useful questions but I am going to snip your text out for
the sake of clarity to let me give you the codec data more clearly.
Your text is attached below.
On 22 Apr 2006, Richard Crowley<rcrowley@xxxxxxxxx> wrote:
You can use a utility (like FREE Gspot) to look inside
your AVI file and see which codec it uses, and what
corresponding codecs are available on your PC to play
it with.
The AVI is a download I got from the Usenet of an adult movie. I
assumed it was made by someone using their own PC to rip an original CD.
At least that is how it sounded from the postings discussing it.
However I get the same poor reply result with most long AVIs I download
from the Usenet: difficult to start in a new position without a very
long pause, after trying new potions I sometimes get a change in the
replay smoothness, etc).
The original AVI is 701 MB and the extracted MPEG-1 is 791 MB. I used
Blaze Media Pro to do the conversion.
If I use GSPOT and AVI CODEC and run them against the AVI then I get the
output I list below.
I also ran Sherlock to list the codecs on my machine. I have chopped
out most of its output as it seemed irrelevant and included below what
was left.
The video players I might use are as follows:
I usually use Media Player Classic (v6.4.8.4) by Gabest.
Sometimes I use Zoom (v4.3) by Inmatrix.
Sometimes I use Windows XP's own Media Player (v10.0000.3390).
If I need to I might use:
VLC (v0.8. 2) by VideoLAN or even Irfanview (v3.97).
I hope this gives you some codec data to work with.
Thanks to you or to anyone else for any feedback.
Andy
----
Output from GSpot v2.21 b030711 ..................
stream type & AV interleave
type==OpenDML AVI, IMRR=1.00
I/L=2 vid frames (67 ms) Split: No
---
comments / metadata
ISFT - software - VirtualDubMod 1.5.10.1b2519
IAS1 = first language - English
JUNK - ASCII
JUNK - ASCII
---
4CC=XVID
5 compatible codecs installed
runtime=00:56:54 (102,322 fr)
640x480
bitrate=1589 kb/s, fps=29.970, 0.173 bits/pixel
---
audio: 0x0055(MP3) ID'd as MPEG-1 Layer 3
2 compatible codecs installed
bitrate=128 kb/s (64/ch, stereo) CBR
Fs=48000 Hz
END OF GSPOT DATA
----------------
Output from AVI Codec v1.1.0.4 (http://avicodec.duby.info).......
video codec=XVID MPEG-4
audio 1 codec=MPEG layer 3
---
Video: 648 MB, 1594 Kbps,
29.970 fps, 640*480 (4:3),
XVID = XVID Mpeg-4,
Supported
---
Audio : 52 MB, 128 Kbps,
48000 Hz, 2 channels,
0x55 = MPEG Layer-3,
Supported
---
File : 701 MB (701 MB),
duration: 0:56:54, type: AVI,
1 audio stream(s),
quality: 75 %
END OF AVI CODEC DATA
=====original email included here for completeness=======
"Andy" wrote...
Recently I downloaded a 700 MB AVI file.
As I played it, I wanted to jump backwards & forwards
in the movie clip. Often when I did this there was a long
pause (5 or more seconds) and then playback resumed
although sometimes it was not smooth.
AVI is not a file format (codec). It is a "container file"
which can hold any of hundreds of kinds of audio/video,
etc files. Actually, both AVI and WAV are particular kinds
of "RIFF" files. http://en.wikipedia.org/wiki/RIFF
You may not have the right codec installed on your PC
for optimal playback performance.
You can use a utility (like FREE Gspot) to look inside
your AVI file and see which codec it uses, and what
corresponding codecs are available on your PC to play
it with.
I got a converter utility and extracted the MPEG-1 file
from the AVI. The MPEG-1 is about 790 MB, so it is
14% bigger than the AVI. But I can jump back and forth
with no problem and no delay.
It is possible but unlikely that your AVI file contained an
MPEG-encoded video stream. More likely you converted
the video in your AVI file to MPEG. And you appear to
have a better MPEG viewer than whatever (unidentified)
codec your AVI file is using.
For the extra 14% i would say it is worth having the movie
as an MPEG rather than an AVI. Would playback quality
of the MPEG-1 be less than the AVI?
Possibly. But the size of your file seems strange. MPEG is
usually smaller than most AVI codecs (and with corresponding
loss of visual quality). But the fact that your MPEG file is
actually slightly larger demonstrates that there are whole
bunches of unkowns here. Of course, the final decision of
whether it looks better or worse is YOU viewing it on your
own screen computer and/or TV screen.
My PC is not fast and maybe I notice those awful delays
more than other people do.
There is likely much more to it than you percieve.
You didn't mention where you got this AVI file?
You didn't mention what software you are using to
view the file?
My question is ... what is it about AVI which makes it
so popular?
It is generally much higher quality than MPEG and is much
more easily edited without further loss of quality. AVI is
much more popular as an acquisition and editing format,
and MPEG as a (final-step) release format. MPEG is
generally much more compressed than AVI, including
temporal compresssion (where not every frame of video
is actually stored in the file, only the difference info from
the preceeding frame, etc.)
There must be many others with a modest PC and who
also find AVIs too demanding.
MPEG files are pretty predictable. An AVI file could have
any of 100 or more different kinds of video inside. It is rather
surprising that you could play it at all without knowing which
codec it uses.
=====end of original email included here for completeness======
.
- References:
- What is so special about AVI?
- From: Andy
- Re: What is so special about AVI?
- From: Richard Crowley
- What is so special about AVI?
- Prev by Date: Re: Upgrading to Hauppauge help please
- Next by Date: Re: Internal video capture card
- Previous by thread: Re: What is so special about AVI?
- Next by thread: Re: What is so special about AVI?
- Index(es):
Relevant Pages
|
Loading
