Heated Debate

[davegee]

I have been looking once again at the settings available when making an H.264 MP4 Video.

The "standard" settings supplied by Igor for a 1920x1080 High Quality MP4 are:

Pan & Scan Enabled

1920x1080

FPS=30p

One-Pass Quality (Mode)

Quality=100

Audio 256 / 44100 / Auto

The one thing that I have yet to see a convincing description of is the MODE setting when using CUSTOM.

Options are:

One Pass - Quality 100

One Pass - Bit Rate with a variable Bit Rate value

Two Passes - Bit Rate with a variabe Bit Rate

The first option is obvious but the Bit Rate options are a little confusing.

Anyone have any insight into this?

DG

[Ken Cox]

DAVE

LOTS OF HITS HERE -- SEARCH WAS OPTIMUM SETTINGS FOR H 264

http://www.google.ca/#hl=en&sugexp=ppwl&cp=22&gs_id=29&xhr=t&q=OPTIMUM+SETTINGS+vH.26+MP4+Video.&pf=p&sclient=psy-ab&source=hp&pbx=1&oq=OPTIMUM+SETTINGS+vH.26+MP4+Video.&aq=f&aqi=&aql=&gs_sm=&gs_upl=&bav=on.2,or.r_gc.r_pw.,cf.osb&fp=da38295ad15965db&biw=881&bih=410&bs=1

KEN

[fh1805]

Dave,

Text below copied and pasted from Wikipedia entry for "Variable bit rate"

"Variable bitrate (VBR) is a term used in telecommunications and computing that relates to the bitrate used in sound or video encoding. As opposed to constant bitrate (CBR), VBR files vary the amount of output data per time segment. VBR allows a higher bitrate (and therefore more storage space) to be allocated to the more complex segments of media files while less space is allocated to less complex segments. The average of these rates can be calculated to produce an average bitrate for the file.

MP3, WMA, Vorbis, and AAC audio files can optionally be encoded in VBR.[1][2][3] Variable bit rate encoding is also commonly used on MPEG-2 video, MPEG-4 Part 2 video (Xvid, DivX, etc.), MPEG-4 Part 10/H.264 video, Theora, Dirac and other video compression formats."

Bearing that in mind, my understanding of the "varibale bit rate" you mentioned is that it is essentially a compression technique that will produce smaller files.

regards,

Peter

[davegee]

ah,

i was not talking of variable bit rate (i dont think?) .

you can vary the bit rate when making custom mp4 files.

which is best single or two passes.

default bit rate is 10000 - is lower or higher better - why?

dg

[Ken Cox]

DAVE

USING PETER'S EXAMPLE FROM

http://en.wikipedia.org/wiki/Variable_bitrate

BEFORE Igor supplied us with a burner, Hawk and I used Nero for burning shows and he swore by double pass - it made a better finished product tho' a bigger file - he had access to a wide screen tv long before the rest of us and he could see the difference and i dont know what Al Robinson used but i have a couple of his dvd disks from our testing days and the quality is superb

we might relate it to 100% saved jpg to a 50 % saved jpg more pixels in the 100%

ken

[Ken Cox]

Dave

here is an old thread

http://forum.videohelp.com/threads/192696-Encode-dv-to-mpeg2-or-mpeg4

and will leave you a bit confused

link from here

http://www.videohelp.com/search.php?cx=partner-pub-7958603558688719%3A6824369548&cof=FORID%3A9&ie=UTF-8&q=double+pass&sa=Search

[Conflow]

Hi Dave,

You Wrote..."One Pass -Bit Rate with a variable Bit Rate value"......."Two Passes -Bit Rate with a variabe Bit Rate"

Yes I can explain this to you: When your Video-Converter or Authoriser-Software is activated you may have a choice

of I-Pass or 2-Pass. (Some software's do not provide that choice).

* 1-Pass is where the System scans each Video-Frame just before Burning it.

* 2-Pass is where the System preliminary scans all Frames (Logs each) and then Burn's each in sequence.

2-Pass is the better of both as it tells the System the total 'Video File-size' of all Frames and each Frame size

consequently its more accurate and virtually error free ~ yes it occupies more space but its temporary whilst the

program is open.

Variable Bit-Rate:- Sometimes this is automatically applied (you have no choice) but good Programs allow you to

choose the limits of the Variable Bit-rate depending on the quality you want. Personally I use a maximum High of

8000kB/s and a low one of 2000kB/s which includes the Audio in AC3-Dolby. The reason for this is that I can nearly

guarantee a 90~95% Replay success-rate on virtually all modern DVD-Players and some not so new but at times

I do get failures on very old Players's. In essence VBR allows the System to calculate the averages of Frame-Data

content and when used with 2-Pass it can allocate more resources to more complex Frames and visa versa.

When it comes to Computer-Replay the sky is the limit up near 16,000.kB/s with PCM-Sound but it depends on the

Read/Write speed of the PC and (minimum) of Twin-Processors ++2.gB of RAM.

Its only really required with HD-Video of 1920x1080 with extremely good Photographs and Fades-to-Black (Top-End stuff)

and there's no guarantee that all modern DVD-Players will handle it ~ and that includes some PC-Monitors !!.

Hope this helps,

Brian. (Conflow)

[davegee]

Thanks guys,

It appears that I have used a word or phrase in (possibly) the wrong place and sent three of you off at a tangent and for that I apologise.

Let's re-group.

When making an H.264 MP4 file (in PTE) we are offered in the first instance some presets with which to work.

If we select a preset and then select Custom we can see what the settings are for that particular preset and we can "customise" them.

All of the presets use the "MODE 1" parameter of "One Pass - Quality" and we could, for instance choose to change the quality setting to a higher or lower value. We could also choose to alter the Audio quality.

I am going to assume, at this stage, that all of the presets and Mode 1 (One Pass - Quality) are VBR (because there is nowhere to specify a fixed Bit Rate).

If we choose to selet a different MODE - we are offered "One Pass - Bit Rate" and "Two Passes - Bit Rate" and the quality setting changes to a Bit Rate setting.

I am going to assume here that MODE 2 and MODE 3 are CBR because we are offered a fixed or CONSTANT Bit Rate (CBR).

It might be a good time to state here, Brian, that this thread/discussion has absolutely nothing to do with making a DVD of any description and therefore the quality of the non-existent DVD Player does not come into the equation. I realise that VBR and CBR might, originally, have been necessary for that purpose but that's not what we are going to do. We are going to make an H.264 MP4 - what we are going to do with it is irrelevant. However, Peter and I have both advocated at one time or another the use of MP4 files for playing on suitably equipped HDTVs and this is my primary use for the files.

So, to get back to my original (intended) question, is there any benefit, when making an H.264 MP4 file for showing on a computer or HD TV, in using the CUSTOM option and MODE 2 or MODE 3 - "One Pass - Bit Rate" and "Two Passes - Bit Rate".

I have already noticed that the default setting of the Bit Rate for the lowest quality file (800x600 - low quality) is 1300 for MODE 2 and MODE 3. The equivalent setting for the highest quality file (1920x1080 - high quality) is 10000 for both MODE 2 and MODE 3.

The Preset Options don't offer us One Pass or Two Pass variants.

So, I guess it boils down to this:

Is there any benefit, when making an H.264 MP4 file for showing on a computer or HDTV, in choosing MODE 2 or MODE 3?

Supplementary question:

Is there any point in setting a bit rate higher than 10000?

DG

[Ken Cox]

DAVE

as one of the threads i gave you stated - there are too many variables

and as the writer suggested start running tests yourself -- compare and what suits YOUR FANCY make future shows that way

ken

[Conflow]

Hi Dave,

You did ask the question about 1 and 2 Pass and 'Bitrates' and I replied in the context of DVD production

as you had not given a specification as what you wanted to do ~ Now thats cleared up in your last Post.

Irrespective whether its DVD or a HD-Mp4 PC-Reproduction the 1-Pass and 2-Pass and Bitrates still apply so

one has to really make up one's mind whether to use CBR or VBR, thats purely a matter of experimentation

to determine the best quality. That of course depends on the limits of the PC's capabilities.

As Ken said its a matter of testing and testing to find what suits you.

Brian.(Conflow)

[davegee]

Brian,

I pointed out that the "mistake" was mine - I mentioned varying the CBR value.

But I still haven't really had a definitive reply?

Assuming that my computer and HDTV are "up to it" is there any value in raising the Bit Rate in the CBR Modes from their default settings of 10000 to 100000 or somewhere in between?

Of course I can try it but there must be a point beyond which any increase in the Bit Rate has no further effect? ....and what applies to my computer / HDTV will not necessarily apply to someone else's Computer / HDTV.

Peter has stated elsewhere that he uses the presets and therefore presumably VBR. I'm tending to agree and no one seems to be able to say WHY those settings are OK and don't require customising.

On another point, Igor has, I think, said that there is little point in using anything larger than 1280x720 but my feeling is that I can see a difference between those settings and the 1920x1080 High Quality settings I am favouring. Is that because of my system or something else?

I thought perhaps we could debate it?

DG

[Ken Cox]

but Dave

Peter has said time and time again he has no interest in making video, has he changed his mind

or are you 2 planning on going on the road trip to Australia to give that fella a hand -- Peter the sound man and you the video man and you are just getting all the chips in order )

ken

[davegee]

Hi Ken,

I know where you are coming from BUT, if you examine Peter's posts carefully I think you'll find that what he actually said is that he has no interest in inserting video into his slide shows - whilst I feel the same way I feel that I need to know about it.

What I'm talking about here is creating H.264 MP4 Video from a "conventional" slide show (sans video) which can be played on a HDTV.

There is a difference.

I don't think that the ex-pat needs any help whatsoever - he is doing nicely (thank you).

DG

[Ken Cox]

Dave

long before video insertion came along Peter said time and again he had no interest in video -- he may have changed his thinking when he bought the new tele' tho' and seen what he was missing

ken

[Conflow]

Hi Dave,

Should have got back to you earlier but I needed some time to thing about your proposal HD-264 for 1920x1080 for TV.

I have been involved with on-going research about this for way over a year now, but unlike yourself I was concentrating

on HQ-(Hi-Quality) 1280x720 in Mp4-Container for TV 16:9 Wide-Screen reproduction which is the TV-entry level for HD.

Whereas you're coming from the PTE HD-Perspective ~ HD-264 1920x1080. I'm only familiar with BBC1-HD and BBC2-HD

and usually for 'run of the Mill stuff' they appeaar to be using 1280x720 but for features they use 1920x1080 as does

(Top-end) Home Cinema productions either on Disc or Transmitted by BBC or Sky.

Yes there is a hell of a difference between HD.1280x720 ~V~ HD.1920x1080 and from what I have researched so far its seems

that 1920x1080 is in RGB Colour-space whereas the lower formats are in sRGB Colour-space. That alone is a major difference.

To see the very real differences you need to have your PC-Monitor properly 'Gamma-corrected' as most are shipped with equal

Gamma for Red,Green,Blue of (approx) 1.19 (applied to LED and LCD Monitors). Proper Gamma is just on 2.2 with slight

variations for Red,Green,Blue ~ this depending on your ambient Workplace lighting and your personal eyesight.

The only problem here is: If your Workplace ambient lighting changes so does the percieved Gamma and PC users tend to see

quite dramatic Colour changes in HD.1920x1080 RGB colour space. The same happens to real HD-TV Programs because the

TV-Set is not Gamma adjusted to correct for colour saturation's in RGB colour-space

There is a heck of a lot more to this than realised ~ but from your point of view Gamma-correction is the 1st.Stop, whereafter its

down to how the Production is put together ~in particular the Codec's used to do that job ~ then and only then have I personally

found myself within 'Ballpark-figures' for Video.Kb's whether that be CBR of VBR. In my case its somewhere between 5600~6800.Kb

and as your 1920x1080 is 2.25 Form-factor greater, I would expect you would be running somewhere between 12600~15300 Kb/sec.

(The above comments are based on personal experiences solely)

Brian (Conflow)

P.S:- I can let you have some Gamma-Tools if needed.

[davegee]

brian,

i really cannot relate to all that.

i have been working with the exe file as my benchmark. i have been looking for a file which looks identical to the exe which can be played on my sony tv and be as near as possible to the benchmark.

let me say straight away that the issues are definitely not colour issues.

the differences i am seeing are mainly to do with gradation. a smooth gradation in the exe is stepped in the mp4. the optimum result is achieved with the high quality preset so hats off to igor for that.

to anyone who wants to go down this route i would urge that the tv be set up with a neutral colour setting. by all means calibrate your monitor but i work on the basis of all elements looking the same - camera nx2 and sometimes photoshop. srgb in camera prophoto rgb insoftware and output in srgb. i do not print.

after doing this since igor gave us the tools i think i am now happy with the result. i did a wedding recently and the customer certainly was happy.

dg

[Conflow]

Hi Dave,

I really appreciate what you are writing and understand your concept of similiarity EXE -to- Mp4 which is required.

Quote..."The differences I am seeing are mainly to do with gradation. a smooth gradation in the exe is stepped in

the Mp4. the optimum result is achieved with the high quality preset so hats off to igor for that"...unquote.

That "stepping" is very evident in Mp4 if you are going it alone,ie:- Doing it yourself with your own Programs/Codecs

etc; which I had thought you were doing ~ My assumption,my error. If you're happy with the PTE-Presets then go along

with them, they are very good, and in consideration that there is no 'Formal-TV Standards' for HD-TV.1920x1080 I also

reckon that the WnSoft-Team have done a great compromise job. I was on the verge of recommending the 'Western-Digital'

HDMI-Media Converter which Ken and others use but thats not a consideration now.

Best regards,

Brian.(Conflow)

[fh1805]

Ken/Dave/Brian,

Just to keep things clear for all; Dave's interpretation of my position is absolutely correct - I have no interest in including video clips in PTE sequences! There are two reasons for this:

- neither of my cameras has video capability

- my preferred AV style is that of documentary on historic subjects

To use digitised historic film clips would add yet another layer of complexity to the already complicated issues of copyright clearance.

However, what I have found an interest in since I got my new HD TV last Christmas is outputing HD video from PTE (via VideoBuilder). Using the HD High-quality Preset and then copying the MP4 file onto a USB stick, I can play my sequences back on the TV for friends to see. I don't have to go through the process of setting up all the computer/projector/speakers hardware; and I get a final result which, when viewed from across the lounge, looks just as good as the exe does when viewed up close on the PC monitor.

regards,

Peter

[Barry Beckham]

Peter.

Yes, I think I agree with you here. With the greatest respect to Igor and his team, video is not for me. I have done a little video to create tutorials, but at this present time, I doubt I will use video myself.

What appealed to me about AV and always has, is the quality of the images we can use. Video, just doesn't cut it, even HD. As for inserting poor quality video taken from the internet, well, what is the point.

There is enormous discussion about video, but is there anything really wow, that is worth seeing. If so lead me to it please.

[davegee]

I agree with both of you but in line with BB's comment I would encourage anyone, if they have the opportunity, to go to one of Andy Rouse's lectures to see how he has incorporated video into his presentations.

He is a MAC user and his presentations are about his photography and not any attempt at Audio Visual as we know it, but if he could only be persuaded to jump ship and become a PC user with PTE - WOW!!!

The other side of that coin is the continued reluctance of died-in-the-wool AV enthusiasts to accept anything new.

What we are seeing is "bad" examples of what can be achieved, but when the Video clips are of the standard that Andy shows that's a whole different ball game.

DG

P.S. Perhaps Howard (Bagshaw) could be persuaded to give us his take on how his incorporation of video was recieved recently when he did a show in Cardiff? I wasn't there but I have heard reports.

[Ken Cox]

DAVE

Some of us have thought that

"The other side of that coin is the continued reluctance of died-in-the-wool AV enthusiasts to accept anything new." many times

also

the ones that say " i would/will Never"

and then wont eat crow when they "see the light"

life is all about change !!!

ken

[davegee]

Ken,

You're so right!

DG

[Barry Beckham]

Dave

I expect you are right that people in general are reluctant to accept change, but if the comment was aimed at me, you couldn't be further from the truth. I am about to go into battle with some here who want to ban video from AV competitions. Although Video doesn't inspire me, the last thing that should be done is to ban it. However, that is the first reaction of the "photo establishment" who feel they must make rules for the rest of us to jump through, whenever anything new comes along.

While I don't personally care for video being mixed with stills much myself I am very careful, not to say "never" I am willing to be converted, to see something that makes me take stock and think again I might be wrong, but so far I havn't seen that from anyone.

[davegee]

bb

my comments were not directed at you.

far from it.

but i think that all should realise that just because we have not seen something does not mean that it does not exist. there are people out there doing wonderful things with the technology but because they do not post their work and have no interest in av or camera clubs it goes unseen by those who think that they might be leaders in the field.

i merely pointed toward one example that i thought was inspirational. his inclusion of video amongst his still shots had relevance and told a part of the story far better than stills alone could do. as you would expect from him the quality of the video matched the quality of the stills.

so based on just one example i am prepared to say that there is a place for video in av. but unless and until there is relevbance and quality in the work forget it. do not do it because it is fashionable or because everyone else is or because you want to be one of the first.

the last thing i want to see in this forum is that things should degenerate to a personal level.

dg

[Barry Beckham]

Fair enough, but you are now sounding a bit defensive and can only point to one example, hardly a landslide is it?

Surely its reasonable to assume that the vast majority of people like to see their Images, Slide shows, video seen by a wider audience. I offer this site and Beechbrook as evidence of that. I am sure there is a PSG one and others too. Many of the contributors here make their shows for others to see, some for camera clubs and some not.

I think that many people on this site, me included are not really sure what to do with our new video capabilities. We don't want to right it off, ban it or make some silly stand saying "I will never use it" just in case we are just not seeing the light yet.

I have to be careful in what I say because I am also turned off by many TV programs because they try to use ginmmicks and fast moving video to make up for lack of interest. Images flashing into negative, jumping across the screen with weird sound effects, then back to the normal video. No video take lasting more than 2 seconds.

So perhaps its just me.

But if it was, we would surely see some great examples posted here. Have I missed them.