Infoseite // VHS capture - + bitrate VBR / CBR + "video encoder quality"

Frage von Sess:


Hi,


I would like to digitize my VHS tapes. In my capture device (; USB 2.0 with SCART input) I can in the software (; magix adjust) the bitrate. As there is only MPEG2 codec.

Then there is "Quality Encoder". Standard on 4, 15 is max. What exactly does this control, I do not know.

But is synonymous with VHS, the higher the bit rate the better the Quallität conservation of the source material?

On the phone said the support type at a higher bit rate would not VHS as the standard 4500 well, the result would be even worse.


What do you think?
Should I stick with 4500 or go for more Quallität but on 6000 and set this 15?

Then there was the question of the bottom or top field first.
As what I should add or cut out in accordance with the export?

By default it takes top to bottom and then exports.

Regards,
Sess



Antwort von tommyb:

The support has no idea.






In general, a higher bit rate is always better, because the bit rate is set too low, the encoder starts s.Artefakte produce. Especially with the MPEG2 Picture suffers greatly, since artifacts can arise block. That is, to muddy Picture of VHS (blurred, indistinct edges) is still synonymous to the ugly block formation of MPEG2.

However: s.einer given bit rate the picture is hardly better. You notice then synonymous forget that if the encoder delivers 15 Mbit despite setting just with large files such as 8 Mbit.

In principle, therefore, is the question: What will happen with the material?

Should it be archived to save space as possible: it extends a bit rate of 4000 Mbit / s, in fact,

Should it turn weiterverabeitet and as with Avisynth filter, then they should be as high as possible.

Will you just burn the stuff only on DVD at maximum quality, it definitely goes a bit rate of 6 to 7 Mbit / s out.





Regarding Top or Bottom:
MPEG2 is really top-Field, but may be forced to be synonymous to bottom-field. I suggest you stay in Top-Field - bottom-field is only required for DV.



Antwort von Sess:

Thank you for your reply.

The support argued something like this: "VHS has had little image information. If one were now the bitrate superscript would be included as bits" so to speak, filled gaps (because so little information). " Irgendsowas ..

The goal is to achieve the optimal Quallität. The size is less important.

I do the recording with Magix. This software is compatible with my capture device.

My preferences would be:


MPEG Type: MPEG-2
Video Format: PAL
Video Bitrate: 6000 kbit / s (of 192 to 15000)
Video Encoder Quallität:? (Of 0 to 15) -> No idea what that is.

Resolution: 720x576
Frame rate: 25
Aspect ratio: 4:3

GOP structure:
I-frames: 12
Auto-GOP: No
Every N-th GOP include: 1
P-frames: 3

Bit rate mode: Variable Bit Rate
Max: 15000
mid: 6000
: 192 min

Audio is 48,000 with 224'er bitrate.

Then there yet multiplex settings, but I guess times are not so important, or the standart is all right.


Is retained on the question of this encoder Qualliät. The numbers seem even multiples of the bit rate to be. But the regulator is not automatic. with high bit rate as soon as I Lifting ..

Somehow confusing?



Antwort von srone:

"Sess" wrote:
My preferences would be:


MPEG Type: MPEG-2
Video Format: PAL
Video Bitrate: 6000 kbit / s (of 192 to 15000)
Video Encoder Quallität:? (Of 0 to 15) -> No idea what that is. adjusting it to 15

"Sess" wrote: Resolution: 720x576
Frame rate: 25
Aspect ratio: 4:3

GOP structure:
I-frames: 12
Auto-GOP: No
Every N-th GOP include: 1
P-frames: 3

Bit rate mode: Variable Bit Rate
Max: 15000
mid: 6000
: 192 min
better constant bitrate 7000, if not possible mid max 9000 7000 5000 min

lg

SRone



Antwort von soan:

I really do not know why the "support" compares the VHS DATA RATE of about 4MBs with a process that converts analog data into digital data and anything else complicated quantization calculations procedures.

I am not an electrical engineer, physicist or anything, but the data rate of the bit rate of VHS her be converted to today's compression methods is surely full of incompetent.



Antwort von Sess:

Why a constant bit rate?

As I just ergoogle there are under constant bit rates Quallitätseinbußen. (Even if I understand it can not, since all the max. Bitrate value is assigned, no preference how much information is being processed). But still, I read das.


Why should I use your knowledge to a constant?



Antwort von srone:

the quality loss is discussed the case of constant bitrate, relates to low data rates (; high compression files) and / or small, if you are bitrate, however, at constant a high, just 7000, choose to create no such qulitätsverlust, which will file just one what little bit bigger so you do not mind as you were writing above. the demand for the constant bitrate why can not necessarily justify technical:
a) saves the rausrendern about 50% of the render time, as only a passage needed
b) produced on playing with one player probably last less cpu when decoding, details of which I suspect synonymous with encode, ie, the risk of misfires on weak calculators is lower
c) gives me a better feeling about the constancy of the quality (the subjective opinion)
point a) does not concern you and the other two points you can connect yourself synonymous or not.

lg

SRone



Antwort von Sess:

All right, thank you for your answer.


If someone else known to his knowledge could do that would be very, very helpful for me. (On the subject of VBR / CBR).

Good night,
Sess


EDIT: One question is whether the above settings only applies to the export or synonymous for the capture? The above settings I have the capture. Can I take there, then export the same as the later? (With respect to VBR / CBR, top field ...)



Antwort von srone:

counter-question you want to edit and cut the material?

I would choose full lotte for capture, ie 15,000 to have corrections if necessary to cbr of room for, and export for the above settings.

lg

SRone






Antwort von Sess:

It will only cut (front and back a few frames off). For the time being. Whether this will aufgebessert later, I do not know.

15,000? So much? G * Fits all still by my USB -2.0 channel?


Remember, if anyone still experiences and knowledge relating to CBR / VBR incl What bit rate can bring in what mode, I would be happy about it much. :)
I sit on hot coals, so to speak, had little time for the whole Capturing and would still like to hear a second opinion.

Regards,
Sess



Antwort von Sess:

Achso, you think I should take only 15,000 if I still want to edit in step BEFORE you export.

Since this is not the case, should I continue to work with 7000 (capture / export).


* Only waiting for CBR / VBR Notes *


EDIT: I once tested:

VBR/7000/4min = 214 MB = 216 MB --- CBR/7000/4min
Then VBR recommended but rather because the place is indeed identical. Only available in hectic scenes more bitrate.



Antwort von tommyb:

There is a CBR mode and two VBR modes.

CBR is, as already mentioned, just the constant bit rate, so it will be at each frame always uses the default bit rate. If you are already so can s.der system limit (max. 8000 kbit / s for copied DVDs, at higher rates it in the jerk Hardware DVD Players), have you a consistently high quality.

Advantage: File size is difficult to predict (kbit 7000: 8 = 875 n.pro seconds, about 3 GB per hour).
Disadvantage: total black passages or those which are not complex, take too kbit 7000 / s. Here we have definitely not in quality.



Then there are the ONE-Pass VBR mode. Here, the bit rate is divided variable, you define a Höchstbitrate, which is as at 7000 and a minimum bitrate (for compatibility reasons it should not be 0). Then there is still dependent on the encoder a "quality factor" to decide whether the work will tend in the high bit rate range, or rather in the low.

Advantage:
Complex passages to get the maximum s.Bitrate, ie here scrape s.der system boundary. Passages which are less complex, eg dark, black, faded images, get far less bitrate. So that the file is only as great as the encoder considers it necessary - the quality of the images, however, remains consistently at the same level.

Disadvantage:
File size is not at all be estimated, it may possibly lead to fluctuations in quality between complex and less complex passages (depending of the "quality factor"). If necessary. Problems cutting of such material.


Now there is the two-pass mode. He acts exactly like the one-pass VBR mode, but just something different.

Suppose you 3 hours Material (without sound) has. If you want to get this on a DVD5 (4480 MB size), one would have a CBR bitrate of about 3300 kbit / s enter (as I said, no sound!). But this would lead with high probability to very miserable quality.

When two-pass, this would be 3300 kbit / s, the average bit rate. In addition, we defined a Höchstbitrate still synonymous, eg 7000 kbit / s and a minimum bit rate, eg 500 kbit / s.

The encoder is now launching its first pass (1st pass) and analyzed the video. It is simply seen only what frames are more complex and what not. The encoder will determine if necessary in the first pass, that 80% of the material is not complex, 15% "means complex" and 5% are very complex.

In the second pass is then encoded. The rechtnet off, how much bit rate of each frame (or GOP) gets dependent of its complexity. 80% of the material is encoded with a bitrate IN 3300, exactly 15% with 3300 kbit / s and 5% have a bit rate between 3300 and 7000 kbit / s.

Advantage:
You get a lot of material in very good quality on a DVD, something not possible with CBR and VBR with one-pass would lead to many Encodingversuche (unvorhersehrbare file size!).

Disadvantage:
It takes twice as long to encode the material - it must eventually go through twice.



Now the question: How exactly should you capture?

You want your material so incised a little, that is, the principle would be the highest quality not that wrong BUT ... You want to cut ONLY yes and no color correction to make turn, right?

If you want to cut only, then it is enough if you kbit CBR with 7000 / s would take. One-Pass VBR falls flat here, because there can be possible problems when cutting.

Note here only that you

1) need an editing program which controls smart rendering (ie passages without color correction and effects are simply assumed to be encoded with no new)

2 get) a maximum of 80 minutes of your material on a DVD5 will




Do you want a little instead s.der Color rotate a little brightening and then burn the 5 hours back to Spain-holiday-movie then DVD, then it is advisable to capture with a maximum bit rate and later - for the final DVD - in Two Pass mode all over again to re-encoding.



Antwort von tommyb:

"Sess" wrote: Then VBR recommended but rather because the place is indeed identical. Only available in hectic scenes more bitrate.
Just thought wrong rum.

In 7000 hectic scenes are available, less hectic scenes at less than 7000 used.



Antwort von Sess:

I want the VHS archive material.

Any I'll get it out again at a iiirgendwann rumzufummeln drann little.


I have a VBR mode 1, but a synonymous fashion 128th (Bitsteuerung) from ONE and TWO, I let nothing pass. Den I can not use it well.

-

If I but at a variable rate as of 7000 had a large file, such as CBR, then I understand why I should take niciht CBR? VBR distributed it better?



Antwort von tommyb:

Please read my post to you through, I'm not free to leave time for writing it (keyword: compatibility).

Two-Pass VBR is the capturing of course not possible.



Antwort von Sess:

I thought this would be a copied text. You've written anything for me? Thank you. :)


Have him carefully perused and understood synonymous.
But a reference to the substance, the file is the same size in cbr / vbr I did not find.


EDIT: Because I have asked the regulator to Quallität-15 is the same size file as VBR uses only the 7000?

Then would one with the highest VBR Quallität almost a CBR?



Antwort von Sess:

1) The material should only be filed in high Quallität.
2) It depends on hard drive, so space is of only secondary importance.


3) I understand now the CBR and VBR modes of thanks to your help. But I still have no idea of which method is for my scenario, the reason most advantageous.


What makes me more Quallität the capture and export?

CBR or VBR 7000 7000?
(And why not VBR when both files were the same size but it does distribute vbr better?)

The time sitting me extremely in the neck, I can hardly sit still and constantly update the Page look here to see if anyone has responded. : \



Antwort von tommyb:

Suppose you have a surveillance video with 1 minute length.

In the first 15 seconds nothing happens, there is no movement, dead trousers. Then, ten sprayer and spray a wall full 30 seconds. You are leaving, we again have 15 seconds a standing Picture.

We hunt now by the encoder.

CBR with 7000 kbit / s:
The file is about 52 MB. All passages are with 7000 kbit / s coded. All passages are looking very good.

One-Pass VBR with Min: 500 kbit / s, Max: 7000 kbit / s and quality factor of 1 (1 = very variable, 15 = no variable):
The file is expected to be 28 MB in size. The passage is 30 sec with 7000 kbit / s coded. The quiet passages with 500 kbit / s coding, because the encoder has so decided (by the quality factor).


One-Pass VBR with Min: 500 kbit / s, Max: 7000 kbit / s and quality factor of 15 (1 = very variable, 15 = no variable):
The file is expected to be 50 MB in size. The passage is 30 sec with 7000 kbit / s coded. The quiet passages with 6800 kbit / s coding, because the quality factor expresses the same time, much of the bit rate encoder can vary as is the quiet passages still bit rate uses more than is necessary, perhaps.



In summary:
This quality set the value you can influence, perhaps really can vary greatly ONLY as the bit rate. So when you start with 1, then vary the bit rate between 500 and 7000th This is actually quite good, because then the encoder responds very dynamically to the image content.

Is set instead 15, then the encoder is working almost as strict as he would run in CBR. That is, the bit rate varies between 6800 and 7000th So you get at your attempt synonymous with a file of almost identical size.


With regard to CBR or VBR:
When using VBR and cut this material, it is possible that some editing programs (especially older versions of them) come with the frames a little confused. Wweil the time stamps are sometimes calculated purely from the bit rate is read completely s.Anfang in the header, then it comes to problems with VBR. Somewhere in the middle of the file changes the bit rate, the editing program that does not respond because it reads this value and already there are problems.

So synonymous CBR.


If your editing program with VBR MPEG2 clearly comes, you take just VBR, but in no case shall this variable bit rate-factor 15, because then you can take immediately synonymous CBR. If value = 1, it could be that although the encoder allocates less complex scenes synonymous less bit rate, bit rate, but this is in fact a little too little. So you probably should work with a value such as 7th






Antwort von Sess:

Thank you again for your time and answer!
Like I can finally get started. :)


Capturing:
VBR (The editing is programmed to clear)
7000 (min 3000 7000 max mid 9500)
Quality standard in 6000 is 4 Actually, in all settings of the standard 4th Get a value between 4 and take your proposal 7th
Top field first

Export:
VBR
7000 (min 3000 7000 max mid 9500)
Quality: 4-7
But which field first? Strangely, the default is for capturing the same "MPEG DVD" bottom field first.

such a conversion is actually useful?



Antwort von tommyb:

No, a conversion should not take place - must keep in Top Field First.

The settings are otherwise so fine.



Antwort von Sess:

Roger that.


Thank you for your help! This brings me good progress in my project.


Regards,
Sess