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scott wrote:
>> The tool I was using *had* a GUI. With 50,000 options on it. None of
>> which appeared to affect image quality. (E.g., increasing the bitrate
>> or the "quality" settings made little to no difference.)
>
> Try XVid4PSP, it's free and so far I have never even needed to change
> any advanced settings. It has presets with names for each format. If
> you choose the format as plain AVI, under video encoding you can choose
> options like "FFV1 Lossless" or "xVid HQ Ultra" or "x264 HQ Ultra" etc.
> Under format you can also choose MP4 Mpeg1 Mpeg2 etc, it really is quite
> easy to use.
>
> It also accepts a huge range of input formats, including VOB if the
> "open file" dialog box is anything to go by.
>
> And of course if you feel like tinkering (I have never needed to), you
> can go and edit the details of each preset.
I installed FFDshow the other day. That seems to give me several
lossless codecs that are nice and easy to use.
According to what Gail said, the tool I used must have been the DivX
encoder. (Or rather, the trail version of it.) I'm going to give Xvid a
try later and see what that does...
(Of course, you never see DVDs that look blurry and messed up.
Presumably that means they figured out how to avoid that in MPEG2.
Unfortunately, MPEG2 is the hardest codec under the sun to find software
for - presumably because they use it on DVDs, so everybody wants to
charge you *money* for it...)
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> (Of course, you never see DVDs that look blurry and messed up. Presumably
> that means they figured out how to avoid that in MPEG2. Unfortunately,
> MPEG2 is the hardest codec under the sun to find software for - presumably
> because they use it on DVDs, so everybody wants to charge you *money* for
> it...)
Xvid4PSP offers MPEG2 PAL and NTSC format options, with encoding options
like "1-pass 8mbit", "2-pass 8mbit", "CBR 9.2mbit", and "copy" which
presumably does no reencoding if your source file is already MPEG2
compatible.
I would expect those would give the same results as a commerical DVD.
But for uploading to YouTube, I would use a more modern codec like xVid
(which they accept) that will give you smaller files for the same quality.
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Mueen Nawaz wrote:
> So I'll tell you what you were told before: MPEG1 sucks. MPEG2 is
> better. If mpeg4 is a headache for you, just do mpeg2.
MPEG2 is very hard to get hold of. It seems that because DVDs use it,
and DVD software costs money, it is not possible to get hold of a free
MPEG2 encoder.
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scott wrote:
>> (Of course, you never see DVDs that look blurry and messed up.
>> Presumably that means they figured out how to avoid that in MPEG2.
>> Unfortunately, MPEG2 is the hardest codec under the sun to find
>> software for - presumably because they use it on DVDs, so everybody
>> wants to charge you *money* for it...)
>
> Xvid4PSP offers MPEG2 PAL and NTSC format options, with encoding options
> like "1-pass 8mbit", "2-pass 8mbit", "CBR 9.2mbit", and "copy" which
> presumably does no reencoding if your source file is already MPEG2
> compatible.
>
> I would expect those would give the same results as a commerical DVD.
Heh. My DVD authoring software [came free with the DVD burner] doesn't
give me quality *quite* that good. (Although it is fairly close.)
> But for uploading to YouTube, I would use a more modern codec like xVid
> (which they accept) that will give you smaller files for the same quality.
At the moment, just getting good quality at all - at *any* filesize -
would be impressive.
What I can't figure out is this: There are dozens of audio codecs that
can take a sound file and make it *at least* 5x smaller with absolutely
_NO_ detectable loss of quality at all. (And far smaller still if you're
willing to sacrifice a little clarity.) But it seems there are no codecs
that can shrink video without a visible loss of quality. (Aside from a
few lossless codecs which usually give you about ~20% smaller or so.)
I guess video is just a much harder problem...
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> What I can't figure out is this: There are dozens of audio codecs that can
> take a sound file and make it *at least* 5x smaller with absolutely _NO_
> detectable loss of quality at all. (And far smaller still if you're
> willing to sacrifice a little clarity.) But it seems there are no codecs
> that can shrink video without a visible loss of quality. (Aside from a few
> lossless codecs which usually give you about ~20% smaller or so.)
Huh? Even MPEG2 (as used on DVDs) can reduce the raw bitrate from 240 Mbit
to 10 Mbit (so 24x smaller) with little detectable quality loss. More
recent codecs will definitely improve on this, like xVid and h264.
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scott wrote:
>> What I can't figure out is this: There are dozens of audio codecs that
>> can take a sound file and make it *at least* 5x smaller with
>> absolutely _NO_ detectable loss of quality at all. (And far smaller
>> still if you're willing to sacrifice a little clarity.) But it seems
>> there are no codecs that can shrink video without a visible loss of
>> quality. (Aside from a few lossless codecs which usually give you
>> about ~20% smaller or so.)
>
> Huh? Even MPEG2 (as used on DVDs) can reduce the raw bitrate from 240
> Mbit to 10 Mbit (so 24x smaller) with little detectable quality loss.
Now compare the MPEG2 video back-to-back with the uncompressed original.
Are you seriously telling me there is *no* detectable loss of quality?
Sure, it's a fairly small loss, but it *is* noticable. I wonder what the
bitrate would need to be increased to for it to be impossible to tell
the difference...
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"Invisible" <voi### [at] dev null> wrote in message
news:490ec9db$1@news.povray.org...
> Mueen Nawaz wrote:
>
>> So I'll tell you what you were told before: MPEG1 sucks. MPEG2 is
>> better. If mpeg4 is a headache for you, just do mpeg2.
>
> MPEG2 is very hard to get hold of. It seems that because DVDs use it, and
> DVD software costs money, it is not possible to get hold of a free MPEG2
> encoder.
http://www.google.com/search?q=free+mpeg2+encoder
The first hit is for the site www.free-codecs.com/download/FreeEnc.htm
"FreeEnc is a free MPEG-2 encoder, which uses avcodec library to encode.
This encoder takes AVISynth input(.avs) and outputs MPEG2 like QuEnc, but
the main difference is that every parameter is tweakable, plus it comes with
the optimized parameters of MencodeMe, which are known to produce great
quality."
The third hit is for www.videohelp.com/tools/HC
"HC is a free MPEG2 Encoder. Input can be a d2v project or input using
Avisynth. 2 pass VBR encoding."
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> Now compare the MPEG2 video back-to-back with the uncompressed original.
> Are you seriously telling me there is *no* detectable loss of quality?
Depends on the content - if your video consists of data you would typically
use PNG to encode rather than JPG, or where each frame is vastly different
from the previous one, then of course it's not going to compress well.
MPEG2 was designed to work well with real life captured video, and it does
that pretty well within the 10Mbit allocated by the DVD standard.
Another example, I made a video of some planets rolling about in POV, the
original uncompressed frames totalled 9.7 GB, after using MPEG4 the video
came out as 28MB, that's 350x smaller! Really, there is no noticeable
difference in quality, I can't tell the difference by looking at a
freeze-frame in VLC compared to the original BMP.
> Sure, it's a fairly small loss, but it *is* noticable. I wonder what the
> bitrate would need to be increased to for it to be impossible to tell the
> difference...
Depends on the content of course.
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scott wrote:
>> Now compare the MPEG2 video back-to-back with the uncompressed
>> original. Are you seriously telling me there is *no* detectable loss
>> of quality?
>
> Depends on the content - if your video consists of data you would
> typically use PNG to encode rather than JPG, or where each frame is
> vastly different from the previous one, then of course it's not going to
> compress well. MPEG2 was designed to work well with real life captured
> video, and it does that pretty well within the 10Mbit allocated by the
> DVD standard.
Commercial DVDs do seem to do this quite well. (For some reason, DVDs I
encoded myself aren't quite as good - although they're still not bad
considering the compression ratio.)
> Another example, I made a video of some planets rolling about in POV,
> the original uncompressed frames totalled 9.7 GB, after using MPEG4 the
> video came out as 28MB, that's 350x smaller! Really, there is no
> noticeable difference in quality, I can't tell the difference by looking
> at a freeze-frame in VLC compared to the original BMP.
That's some pretty steep claims. ;-)
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> That's some pretty steep claims. ;-)
Here's the difference scaled up by a factor of 32 from one frame. You
cannot see the difference even when studying the two stills closely.
Post a reply to this message
Attachments:
Download 'diff.png' (254 KB)
Preview of image 'diff.png'
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