Why use 23.97fps for downloads.

[noreaster]

I am becoming increasingly frustrated with the latest practice of making downloaded avi files in NTSC with a 23.98fps.

I am a retired analog Broadcast Engineer & I was under the impression Ntsc was transmitted 29.97fps and PAL at 25fps.

I understand the telecine process of pulldown but most of the programs transmitted are on Tape so why complicate it with a slower compicated fps. Any film is upconverted to 29.97fps at the transmission point. Isn't it?

Unless the transmission standards have changed dosn't NTSC transmit 29.97fps lets ignore progressive scan rates for the moment.

To have a program transmitted at 29.97fps then the person offering the copy converted to 23.98fps and to try to make a DVD of this is complicated and the results invariably have jerky playback on pans.

Why are we making the NTSC system so complicated. Transmit the program at 29.97fps save the file with the same fps and it will playback without any jerkiness.

I have had to resort to confuse my DVD player into thinking that it is recording 29.97fps with DVD Patcher. That way I get smooth playback.

Give me PAL anyday

[pijetro]

Well, then your frustration should be at the film industry, since they're the ones who created it..

Any film is upconverted to 29.97fps at the transmission point. Isn't it?

Ahh, there's the rub...
Essentially, your DVD player is playing a film rate, but repeating the frames, so you get a 29.97 playback..Sort of like fooling NTSC..

I sympathize with your thoughts on the issue, but the main reason many people prefer 23.976fps, is that, since you've removed reduntant information (ie Inverse Telecine), you can punch up the bitrate and get potentially better quality per disk..

[lordsmurf]

I don't have any sympathy for you. Zero.

Stop with the downloads.

Either buy it, wait for it to be released and buy/rent it then, or have enough forethought to record it off tv yourself (or get a friend to do the favor for you, or have friends with a similar interest, so that one of you gets it). VCRs, DVD recorders and TIVOs all have timers.

Even the best downloads tend to look like crap.

The issue you face is the suppliers of downloads (the original uploaders) usually don't know anything about video. They tend to be a bunch of stupid nerds (usually 14-22 age range) that think uploading is cool. Or they feel they must upload because of all the crap they download (leeching). There is also a huge laziness factor, with most of them unwilling to learn and having this careless "so what" sort of attitude as it relates to quality and proper video methods.

[guns1inger]

Look at most NTSC movies and you will find they have been encoded at 23.976, with pulldown flags inserted to tell the player how to playback the film for 29.976. I have had occassion to convert files like this in the past (public domain or done within copyright, Mr. Smurf), and I have been able to achieve smmoth output by encoding at 23.976, inserting the pulldown flags, and authoring. This is definately preferable to trying to encode them as 29.976, which invariably does lead to stutter.

You don't need to confuse your player, it is built to do this. You just need to tell it when (the pulldown flags). I suggest you look into DGPulldown and 23.976 encoding.

[Mr2001]

I understand the telecine process of pulldown but most of the programs transmitted are on Tape so why complicate it with a slower compicated fps. Any film is upconverted to 29.97fps at the transmission point. Isn't it

Yes, but remember, programs that are shot on film only have 24 "real" frames per second. The other 5.97 fps are created by the pulldown process using parts of other frames. There's no point in encoding those extra frames if you don't have to, since your DVD player can reconstruct them (and if you play back on a computer, you don't need them at all). As pijetro said, if you don't encode those redundant frames, you can get better quality on the frames you do encode.

To have a program transmitted at 29.97fps then the person offering the copy converted to 23.98fps and to try to make a DVD of this is complicated and the results invariably have jerky playback on pans.

Why are we making the NTSC system so complicated. Transmit the program at 29.97fps save the file with the same fps and it will playback without any jerkiness.

It shouldn't be complicated. Any decent DVD authoring software can deal with 23.976 fps video, because every film that comes out on region 1 DVD is 23.976 fps.

And if the IVTC/pulldown is done correctly, there should be no difference in "jerkiness" at all. The player will reconstruct the redundant frames exactly as they were broadcast.

Now, if the original NTSC broadcast was shot on video (most sitcoms, news reports, soap operas, porn...), then applying IVTC is inappropriate and it'll cause jerky motion in the end result. But no one should be doing that.

Either buy it, wait for it to be released and buy/rent it then, or have enough forethought to record it off tv yourself [...] Even the best downloads tend to look like crap.

Heh, you must be joking. Home recordings tend to look even worse unless your PVR can record an MPEG stream straight from satellite or digital cable. My TiVo recordings look like crap compared to every PDTV/HDTV rip I've ever seen.

[lordsmurf]

If your home recordings look worse than a download, you did something wrong. It's as simple as that. Period.

[Mr2001]

If your home recordings look worse than a download, you did something wrong. It's as simple as that. Period.

OK, please explain how I can make my analog TiVo recordings look better than an HDTV capture encoded in XviD. I'm all ears.

[canadateck]

I wish My captured Analog Video looked as good as HD.

[BobK]

OK, please explain how I can make my analog TiVo recordings look better than an HDTV capture encoded in XviD. I'm all ears.

Get rid of your analog TiVo and get capture HDTV yourself.

[lordsmurf]

Mr2001, you are arguing to merely argue. You're not getting HD XVID files, you're getting HD files that are downsized, often with added mattes to retain widescreen.

You can do that at home if you want, get a PVR computer system equipped with a HD capable card, and then encode to a true DVD spec (16:9 if you want). But do it to a good MPEG-2 encode. Not XVID.

While TIVO is certainly no pinnacle of video quality, it's certainly not "bad" by any means, and if it is, it may be defective or in need of repair. Also be sure to use the good quality mode, not the highly compressed modes.

[edDV]

For reference: I still like this writeup best for helping people understand progressive video on DVD players.

http://www.dvdfile.com/news/special_report/production_a_z/3_2_pulldown.htm

[Mr2001]

Mr2001, you are arguing to merely argue. You're not getting HD XVID files, you're getting HD files that are downsized, often with added mattes to retain widescreen.

I'm just trying to point out the fallacy of your statement. Downloaded files don't look bad in any objective sense. They might look bad to someone who's used to watching unadulterated HDTV streams, but those people are a minority. I would rather watch a resized XVID version of a show, captured from a digital source, than an original analog cable broadcast any day. (The deinterlacing might be a problem for sports, but I don't watch sports.)

You can do that at home if you want, get a PVR computer system equipped with a HD capable card, and then encode to a true DVD spec (16:9 if you want). But do it to a good MPEG-2 encode. Not XVID.

Unfortunately, all that high quality equipment comes at a price. Perhaps you should've said "Either buy it, wait for it to be released and buy/rent it then, or have enough forethought and money to record it off tv yourself".

And coming back to the OP... if you were to capture the HD streams yourself, you'd probably find that they were 24 or 23.976 fps anyway.

While TIVO is certainly no pinnacle of video quality, it's certainly not "bad" by any means, and if it is, it may be defective or in need of repair. Also be sure to use the good quality mode, not the highly compressed modes.

I use "high" quality. I've never noticed a difference between "high" and "best" except the file size. TiVo's MPEG encoder is infamous for its cheapness.

[edDV]

And coming back to the OP... if you were to capture the HD streams yourself, you'd probably find that they were 24 or 23.976 fps anyway.

I haven't seen one at 23.976 fps yet although they could within the ATSC standard. Typical HDTV broadcasts are

1080i (1920x1080) 29.97 fps with the same old 2:3 telecine field sequence if film.

720p (1280x720) usually at 59.94 progressive frames per second. In this case full progressive film frames are repeated in a 2:3 sequence in a similar manner to a progressive DVD player. Sometimes 1080i material (particularly film commercials) are converted to 720p and played at 29.97 fps.

[lordsmurf]

in any objective sense.

I would totally disagree with that. They often have audio level issues, glitches in the encodes, crappy editing jobs, and video/audio frame latencies that are AT LEAST 2-3 frames at best, often 10-30 frames at worst (meaning sync errors). Encoding methods also leave much to be desired. As I said earlier, clueless nerds.

In a "subjective" sense, sure. Some people are fine with crap. Look at all the people that deinterlace or make 6-hour DVDs and say "it's fine".

"Expense" is also a cumulative and subjective thing. The truth is, downloading and converting costs far more time and money than simply doing it yourself. Not to mention it stresses out and abuses Internet bandwidth. And we didn't even address legalities, it has plenty of negatives without that mess. You might also want to note that ADVOCATING WAREZ is against forum rules, and this is certainly coming close to that.

The current HDTV standard, as edDV just pointed out, really doesn't use, encourage or support 23.976. The reason people use 23.976 online is they simply don't know any better. When you download videos online, you're at the mercy of the encoders, and in most cases, that person is an idiot.

[Mr2001]

I haven't seen one at 23.976 fps yet although they could within the ATSC standard.

Interesting. Perhaps I'll learn about HDTV first-hand someday if the sets ever become affordable. I swear, someone must be sneaking into electronics stores at night and drawing extra zeros on those price tags...

Encoding methods also leave much to be desired. As I said earlier, clueless nerds.

Am I the only one who finds it hilarious that you're calling people "nerds" on a message board devoted to the intricacies of digital video?

In a "subjective" sense, sure. Some people are fine with crap. Look at all the people that deinterlace or make 6-hour DVDs and say "it's fine".

I guess I meant "absolute", not "objective". I've seen video that I had no problem calling "bad"... most TV downloads, IME, are only bad in comparison to extremely high-quality TV sources that most people have never seen.

You might also want to note that ADVOCATING WAREZ is against forum rules, and this is certainly coming close to that.

While I am certainly not suggesting that anyone break the law, it's important that we remain honest about what's out there. Just as we shouldn't spread misinformation about the dangers of illegal drugs, we shouldn't spread misinformation about the quality of illegally copied video.

The reason people use 23.976 online is they simply don't know any better.

Well, what frame rate would you suggest for a program that was shot on film and telecined before it was captured? Why bother encoding those redundant frames?

[lordsmurf]

You assume too much. Very little of what is shown on HD is telecined. Anything that has been edited (which is most content) or had CG added to it is usually done in the 29.97 domain. So your film was lost generations ago by the time it reaches your hands. Using 23.976 is something you would need to do on rare occasion. Surely not the norm. Not to mention telecining is a brutal process, and quite often leaves behind unsightly chroma interlace artifacts that cannot be compensated for.

The original poster asked a good question, which was quite honestly rhetorical. He's just looking for confirmation on his well-based assumptions. And the concurring response is "yes, people online do it wrong". I went one further by stating that you really should not be doing it anyway, especially for this reason.

Please read the dictionary for "nerd": nerd: A foolish, inept, or unattractive person. Please take note of the words "FOOLISH" and "INEPT". That would be what I am referring to. These P2P nerds do things without doing them properly.

[Shadowmistress]

Now boys.... play nice....

To answer the op's question, it's probably about filesize. You get "smooth enough" playback with a bonus reduction in avi filesize. Less to download.

I don't know anything about pulldowns and how my dvd player fakes 29.97 fps, but now I want to learn. If I can encode my mpgs to 23.976 non-interlace and have them play back properly, I can squeeze a whole shitload more onto a dvd. (Lordsmurf's probably about to pop a vein in his forehead now. ) I'm a recent VCD user so I don't care about perfect quality. :P

Can anyone pass me a link on where to start my learning process on this?

[jimmalenko]

Well .... its' obvious, isn't it ?


This is all in theory, mind you


Say you've got a bitrate of 3000kbps. Now you can stretch that bitrate over 29.976 frames (1 second of footage), or you can stretch it over 23.976 frames. Obviously the latter will allow more bits per frame, therefore resulting in better quality, or from the other angle, a smaller filesize than the 29.976 one, since you can reduce the bitrate on the 23.976 one to keep the same quality.

All you need to do is encode @ 23.976fps with a 3:2 pulldown on playback. Your DVD player should then play this back smoothly. TBH, we're not talking about "a whole shitload more" though - in effect, it's about another 20% while retaining the same (or similar) quality as I understand it.

[Shadowmistress]

20% is alot if you're putting upwards of 15 hrs on a dvd @ 29.97 fps.

--But thanks.

[jimmalenko]

20% is alot if you're putting upwards of 15 hrs on a dvd @ 29.97 fps.

Oh dear god !

"avert your eyes, children ..."


Are we talking SL or DL ?

[edDV]

...

I don't know anything about pulldowns and how my dvd player fakes 29.97 fps, but now I want to learn. If I can encode my mpgs to 23.976 non-interlace and have them play back properly, I can squeeze a whole shitload more onto a dvd. (Lordsmurf's probably about to pop a vein in his forehead now. ) I'm a recent VCD user so I don't care about perfect quality. :P

Can anyone pass me a link on where to start my learning process on this?

Start with the link I posted above for the big picture. There has to be a rather pure telecined film source to make IVTC to 23.976 work at all. I guess if you are trying to put more than two hours on a DVD, you don't care much about quality.

[edDV]

20% is alot if you're putting upwards of 15 hrs on a dvd @ 29.97 fps.

--But thanks.

If you are compressing that much why maintain 29.97? You get 50% improvement going to fields and another 50% dropping to 14.98 fps

[G)-(OST]

20% is alot if you're putting upwards of 15 hrs on a dvd @ 29.97 fps.

COOOOOL!!!! I think

[Shadowmistress]

@jim: . Single layer. 20x45min eps.

@ed-tv: really? What's fields? And I tried 14.98 on a re-writable before but my dvd player stuttered on playback.

Are you saying I can actually squeeze more out of it? Show me how and I'll love you forever!

If I could put all 7 seasons of ST:TNG on one disk and never have to worry about which ep is on which disk, I would. That would totally rock! But even I realize that's just a pipe dream.

[guns1inger]

How do you tell which blurry blob is who ?

[edDV]

...

@ed-tv: really? What's fields? And I tried 14.98 on a re-writable before but my dvd player stuttered on playback.

Sure it will stutter @14.98 fps.

If I could put all 7 seasons of ST:TNG on one disk and never have to worry about which ep is on which disk, I would. That would totally rock! But even I realize that's just a pipe dream.

Just wait for 50GB Blu-Ray.

[lordsmurf]

If I could put all 7 seasons of ST:TNG on one disk and never have to worry about which ep is on which disk, I would. That would totally rock!

Some of you people will never be satisfied.

A few years ago, the comment would have been "I wish I could put all of ST:TNG on one shelf".

Now it's "I wish I could put all of ST:TNG on one disc"

Next it'll be "I wish I could put all of the ST:TNG, ST:TOS, STS9, ST:VOY, and ST:ENT all on one disc"

Then it'll go "I wish I could put all my sci-fi shows on one disc".

Followed by "I wish I could put every video I have on one disc".

And eventually you'll get down to "I wish everything I have that can be digitized fit on one disc"

And let's not forget "I wish these discs weren't so big".

[Shadowmistress]

How do you tell which blurry blob is who ?

It's actually not that bad. It's not exactly good, mind you, but on a 27" tv when I just mostly have it running in the background for the sake of avoiding commercials and falling asleep to, it does the job.

Now my sister has one of those theatre type tv's and I wouldn't dare pop a disk like that into her dvd for fear of getting laughed right out of the neighborhood. When I make disks for her I barely go beyond 2 hrs maximum cause it REALLY looks crappy and even I wouldn't watch that.


@ed: thanks. :P

[Shadowmistress]

Next it'll be "I wish I could put all of the ST:TNG, ST:TOS, STS9, ST:VOY, and ST:ENT all on one disc"

Daaaaaamn..... smurf, you're killing me. Putting blasphemous thoughts into my head.

Actually, if they just made dvd players that held 15-20 disks so you don't have to actually load and unload them, that would probably solve alot of problems.


(But then of course, I'd want 50-100)

[jimmalenko]

@SM:

How does a DIVX/XVID settop player grab you ?