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-   -   FFMPEG: Ffvfw VIDEO CODEC (http://www.digitalfaq.com/archives/encode/7913-ffmpeg-ffvfw-video.html)

incredible 02-04-2004 06:25 PM

@ Racer 99

Thank you very much for the links!!! ;-)

But in CBR mode we don't suffer from that VBV issue any more.


But anyhow, thanks a lot.



Inc.

Hydeus 02-05-2004 04:41 AM

Quote:

Originally Posted by Krassi
I've just tested the 1-pass-quantizer-mode (@2)
At first view, it seems to be great. Filesize is about 40% less. I have to verify that 8O

Yes it is. Picture quality is also pretty acceptable (litle blured vs CBR). But again we have VBV at 7 as with Quality mode :(

For the other hand:
I've tested CBR mode with VBV 20 and 24. I always get bitrate peek at ~4000 even above 5000. I think that for KVCD this is unacceptable. Can I look forward for litle explanation (as short as possible) of VBV part in encode/decode process? Even with bitrate at this high level, this files are playable on standalone. Maybe I'm lucky :)

rds_correia 02-07-2004 07:27 PM

So,
No posts since 05-02...that's it :?:
Can't believe that the thread is dead 8O
Even because we're still missing 20 pages if we want to match the record of CQ vs CQ_VBR :!:
Come on guys. Cheer up and post your ideas.
C ya

Jellygoose 02-07-2004 07:45 PM

Well as for me, I'm done with this Codec... Sorry to say.

After heavy testing, I don't see a way to limit those bitrate peaks (15000 and more). When we find a way to fix that it'll be great. Until then, I already spent too much time on it! :wink:

kwag 02-07-2004 07:51 PM

Quote:

Originally Posted by Jellygoose
I don't see a way to limit those bitrate peaks (15000 and more)

8O I never had a peak of over ~8,500, when using KVCD's Q matrix :!:
Is that at 704x576 :?:
Maybe that's why, because at 704x480, I never reach the MAX (for DVD) which is ~9,000Kbps (9,800?, don't recall now).

-kwag

Jellygoose 02-07-2004 07:58 PM

That's 704x576 Quantisizer 2, with the 6000 something Bitrate set (for 224 kb VBV) and the Notch matrix and a simple resizing script. Even with Quantisizer set to 3 i get peaks of ~9000 and the texture quality for plain surfaces decreses a lot. :roll:

vhelp 02-07-2004 08:04 PM

Well, I don't seem to ahve any problems w/ this codec :P

It's ok, but I do have one or two quams about it..

1) - Debuging "blindly" is a prblem w/ me.. (ie, no PREVIEW on some items)

2) - it takes approx 1 minute for it to respond back, when I have to go back
and make a change in the compression. It's like it goes to sleep and then
finally wakes up, "oh, I'm ready now.. you mak enter.." or something like
that.

3) - I can't complain about quality. I found it very close to my TMPG encoding.
That's for MPEG-2 source. Can't say for MPEG-1, cause TMPG is suppose
to be much better w/ those :P but I'm not a fan of MPEG-1 anyways :P

4) - lacking in better interface. There's need for a GUI. I'd do it, but I'm
not familiar w/ this .dll communiction of opening up a codecs Config box
and directly modifying it contents (as though you went through the vdub
and Compression route. I know this is possible, because I've done it once
before (beta-testing an idea some time backwards ago) - - Like I said, I'd
cook one up if I knew how to call it from my Delphi app. As my understanding
goes, most of the settings get saved in the .reg file anyways. But, you still
have to call the Config (or is it Settings) to make the actual settings/changes.
Mind you, I was researching this, but then I thought it was more important
to find a MUX/deMUX/Multiplexer for these .avi wrapper files. (see below)

5) - better (cleaner) method to MUX/deMUX/Multiplex the source for a proper
DVD author project. Something needs to be created that will allow a user
to just drag 'n drop (my favorite app feature) and let it do it's thing (based
on a profile, that is user-configurable)

Basically, the above is a short recepee (or wish list) for tweaks/features.
Feel free to add to it, if need be.
.
.
My favorite are two.. Better GUI (need to create one) and MUX/Multiplexer

But, I still prefer my TMPG encodes to MPEG-2 in the mean time.
Well, we'll see what new things happen, but there's room for others here to
contribute (ideas/methods/process etc etc)

-vhelp

vhelp 02-07-2004 08:10 PM

@ jell and kwag..

In an effort to come to a resolution (not screen'wise) perhaps, if you both
agree w/ a DVD source, and both do the same scene, using the same params
and see where you both compare (or go off)

Next, you can then fine-tune the issues.

How does that sound to you guys ??
Heck, I'd jump in too, just to see what I get. Then, we three can post our
final BitrateViewer results here - - Yeah ??
I've lot loads of DVD's just aiking to be push into battle hehe..

-vhelp

Jellygoose 02-08-2004 06:31 AM

@vhelp: Well I'd surely join your testings, but I don't see how we can "fine-tune" that codec, so that it won't produce such high bitrate peaks. :roll:
Even if it will work with the material that we all use for testing, there's no way I can get my DVDs here to work with it. I limited the bitrate peaks to about 11.000 but that's not what I want at all... :?

vhelp 02-08-2004 05:54 PM

Hi Jellygoose,

Correct me if I'm wrong, but...

Shouldn't our goal be to "mimic" as closely the bitrate values that are in
the DVD, but at a lower projected size (ie, SVCD or re-encoded dvd proj) ??

I always thougth that as long as you maintained the same level of bitrate
spike (spike for spike) that, THAT is the ultimate goal. So, say our DVD
disk is spiking between 1kb through 7.4kb, that would be considered normal
for a DVD title.. BUT, now we want to re-encode to say, dvd (notice how I
use small letter to signify our re-encode) and our new goal is now to produce
bitrate spike (per our new encoding method/process plus N.Matrix) to our
new 700 to 4.5kb, we should now have the same spikes, but w/in a lower
threashold.
Now, I do realize that this may not work in our real-world encoding because
we have different MPEG encoding engines/algorithems etc., but I still think
we should always have the goal to come close. But still, it's prob. pointless
because we are encorporating Filters and different methods of resizing and
setting our Aspect Ratios, of which may alter the bitrate pathways etc.

Sheesh.. I hope I made some sense here. If not, blaim it on my NEW mobo..
I woke up to a dead pc this morning, and I was really pissed, cause I had
lots of things open that I needed to finish up on..
RaTs

-vhelp

Jellygoose 02-09-2004 06:05 AM

Well I agree with you in most parts vhelp. But that is exactly the problem of this Codec for me. It does NOT produce DVD-Compliant Bitrate peaks. On the other side it goes down to 200kb/sec and that is also not DVD compliant I believe. And I don't see a way how we can fix this yet.
So I'm asking you what you intended with your post. :roll:

vmesquita 02-09-2004 06:26 AM

Quote:

Originally Posted by kwag
8O I never had a peak of over ~8,500, when using KVCD's Q matrix :!:
Is that at 704x576 :?:
Maybe that's why, because at 704x480, I never reach the MAX (for DVD) which is ~9,000Kbps (9,800?, don't recall now).

-kwag

Just to clarify: the DVD bitrate peak is 9800, considering audio :!: So if you have a 192 kbps audio track for instance, your max peak for video should be 9608 kbps. :wink:

kwag 02-10-2004 11:35 AM

Quote:

Originally Posted by vmesquita
Just to clarify: the DVD bitrate peak is 9800, considering audio :!:

Actually, from the link below :arrow: "Maximum video bit rate is 9.8 Mbps."
http://www.dvddemystified.com/dvdfaq.html#3.4 ;)

-kwag

vmesquita 02-13-2004 10:19 PM

But it doesn't make sense... So if you decide to put eight 448 kbps audio tracks (in theory), total bitrate would go up to 13384... I'll mail the guy and confirm.

vhelp 02-13-2004 10:38 PM

Hay guys, TGIF..

I'm curious. I've ben still testing ffvfw out w/ my setup, and so far, I can't
really complain. But, ...

I'm wondering which movie's are giving your guys the high spike, and at
what bitrate were you using at the time ??

I'll give you an example of a scene for you guys to test this spike out with.
.
.
Good movie to test spike w/ is Fifth Element. Very end of Chapter 6, I believe.
If there is a spike lover in a given snenario, this is it. Just rip Chp 6/7
together, cause the spike runs through the transition to Chp 7. Only a minutes + worth of your encoding time :)

I'll post the spike, based off my ffvfw encode if you like !!
-vhelp

Hydeus 02-14-2004 03:22 AM

For me i get 4000 to 6000 bitrate spike at 352x288 res on cartoon (Futurama). And with movies i get the same values at DVD res. But i use quantizers no highrer than 3 or 4 (for beter quality). I know that rising quantizer to 6/7 gives reduced spikes to 50% of this.

Jellygoose 02-14-2004 11:35 AM

Quote:

Originally Posted by Hydeus
For me i get 4000 to 6000 bitrate spike at 352x288 res on cartoon (Futurama). And with movies i get the same values at DVD res. But i use quantizers no highrer than 3 or 4 (for beter quality). I know that rising quantizer to 6/7 gives reduced spikes to 50% of this.

This is just not what we aim for. If we lower the Quantisizer to 5/6 of course the spikes will be under 6000kb. But that is due to the lower AVERAGE bitrate. The spikes are still there, most likely as high as with Quantisizer 2 if you compare the spike to the average Bitrate.

vhelp 02-14-2004 12:12 PM

hay Jell..

question..

But, where are you getting the spikes from ??

I'm assuming that your spike issues are from scenes that are not "spike-worthy"

IOW.. are your scenes slow-moving, but spiking in them ??
Or, fast-moving, and spiking w/ good reason.. but maybe just TOO spiking ??

Here is screen pic of btviewer's results of my previous discussion of the
movie, "The Fifth Element" (chp 6/7) ...

http://www.digitalfaq.com/archives/error.gif

-vhelp

vhelp 02-14-2004 12:15 PM

Jell,

If you've sceen the scene, you'd understand why the bitrate went up that
high. Fire does that !! But, the nature of THAT scene called for such a high
bitrate. I agree w/ it's decision to 6.5k it.
.
.
But, w/ respect to that pic I posted above, and that scene, IMO, lowering
the spike (I mean, bitrate) would only make that scene blocky ??

I have the 4.1mb clip too.. if you wanna see that, but if you have the dvd,
then you don't need it, right ??

Anyways..
-vhelp

Jellygoose 02-14-2004 01:17 PM

@vhelp:

You're totally right, a spike of 6.5k in that scene (fire) is totally ok, and might be needed for such a scene.
The spikes I'm talking about DO appear in such high-action/movement scenes, and also might be totally rectified for such a scene. That doesn't change the fact that a spike of ~14.000 is just not DVD-compliant. By the way, I also got an average bitrate higher than yours, which totally fits my theory. for an average bitrate of 1663 a spike of 6500k is extremely high. almost 4x the average bitrate. Now if you need an average bitrate higher than that (noisier source for example), let's say 2100 kb/sec that would also be a spike of 8400kb/sec max. bitrate. and my spikes are even higher, as said.
:arrow: no way to specify max. bitrate :arrow: this sucks 8)


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