I've been reviewing some technical info on framerates on NTSC Video. Due to a lot of framerate changes in videos, I've been using -fps 120000/1001 to get the 29.97fps rate for standard TVs. However, having seen a lot of the "telecine jitter" caused by the 3:2 pulldown process, I have some questions. Most films are 24fps. I watch almost everything on a computer or laptop, so I'm wondering if it's worth keeping Movies at 30fps(which would be good only if I actually used a TV) and instead keeping them at 24fps. TV shows are recoreded at 30fps anyway, so that's not an issue. Also, what about using an ATSC TV for HD at 480p? Would newer standards work better with 24fps? Any comments? Thanx
On 11-03-21 4:19 PM, larrystotler@netscape.net wrote:
I've been reviewing some technical info on framerates on NTSC Video. Due to a lot of framerate changes in videos, I've been using -fps 120000/1001 to get the 29.97fps rate for standard TVs.
However, having seen a lot of the "telecine jitter" caused by the 3:2 pulldown process, I have some questions.
Most films are 24fps. I watch almost everything on a computer or laptop, so I'm wondering if it's worth keeping Movies at 30fps(which would be good only if I actually used a TV) and instead keeping them at 24fps. TV shows are recoreded at 30fps anyway, so that's not an issue.
Also, what about using an ATSC TV for HD at 480p? Would newer standards work better with 24fps?
Any comments? Thanx 120000/1001 = 119.88 fps
I generally use this combination of things -fps 30000/1001 -vf pullup,softskip,harddup -ofps 24000/1001 to get to the actual original (assuming NTSC source material) film frame rate of 23.976 If your source material is variable frame rate, it's up to you to pick one - the safest bet is to keep it at 29.97 fps and use a deinterlace filter (such as yadif). Yadif isn't perfect, nothing is. You can use pp=lb but some people find the result too soft. If the source is mostly film, then use the pullup and softskip filters, but follow them up with yadif to clean up the few video frames that sneak in as best it can. And no, TV shows are not recorded at 30fps necessarily. Some are produced in HD at 24fps. Looks more "movie like" that way.
-----Original Message----- From: James Hastings-Trew <jimht@shaw.ca>
120000/1001 = 119.88 fps
Sorry. I use 120 to get the average of 24 & 30.
I generally use this combination of things -fps 30000/1001 -vf pullup,softskip,harddup -ofps 24000/1001 to get to the actual original (assuming NTSC source material) film frame rate of 23.976
Why are you using -fps & -ofps? An example is Willy Wonka. I've encoded it to 120, but the original looks like it's a 24fps. so, if I use 24000/1001 would I see less lag on wide panning slow scenes? I guess I'll have to watch the screen capture of the encoding to see if it switches up alot.
If your source material is variable frame rate, it's up to you to pick one - the safest bet is to keep it at 29.97 fps and use a deinterlace filter (such as yadif). Yadif isn't perfect, nothing is. You can use pp=lb but some people find the result too soft. If he source is mostly film, then use the pullup and softskip filters, but follow them up with yadif to clean up the few video frames that sneak in as best it can.
I generally don't use any extra options. I've started using -vf crop= on some things, but I haven't really decided it's worth. A lot of the options you are using are a little confusing to me. Of course, I've been using the same basic options since 2006 with XviD(I have a bunch of older machines that stutter using an h.264 codec - and my Axim plays better with them).
And no, TV shows are not recorded at 30fps necessarily. Some are produced in HD at 24fps. Looks more "movie like" that way.
True. Newer ones are moving to that. Which is why I was wondering about ATSC specs. What about cartoons? I've read that they generally use 12fps except for scenes with a lot of action. They seem to stutter at 30fps. Thanx
Hi!
I generally use this combination of things -fps 30000/1001 -vf pullup,softskip,harddup -ofps 24000/1001 to get to the actual original (assuming NTSC source material) film frame rate of 23.976
From your answer, I assume you do not know the pullup filter. Please test it with above command line on various telecined material, I believe it will answer many of your questions. (While de-interlacing always invents pictures that were not there before, the pullup filter should be able to output the original 24fps video, even for most badly cut source material.)
Carl Eugen
-----Original Message----- From: Carl Eugen Hoyos <cehoyos@ag.or.at>
From your answer, I assume you do not know the pullup filter. Please test it with above command line on various telecined material, I believe it will answer many of your questions. (While de-interlacing always invents pictures that were not there before, the pullup filter should be able to output the original 24fps video, even for most badly cut source material.)
No I didn't. I read about it and see the usage now. However, still have some questions: 1. the man pages said not to crop while using pullup. How would I crop? I've tried to go back and crop already encoded material, but it doesn't see to work. 2. The movie Blue Streak has a framerate switch at 4650.4 & 4650.8 seconds(to 30, back to 24). It happens at an explosion in the movie. How do I account for that? Is this what pullup is for? I don't really plan to go back and redo everything I already have unless it's a really big change. I use 2 pass XviD with 1 Thanx
On Tue, Mar 22, 2011 at 5:25 PM, <larrystotler@netscape.net> wrote:
-----Original Message-----
From: Carl Eugen Hoyos <cehoyos@ag.or.at>
From your answer, I assume you do not know the pullup filter. Please test it with above command line on various telecined material, I believe it will answer many of your questions. (While de-interlacing always invents pictures that were not there before, the pullup filter should be able to output the original 24fps video, even for most badly cut source material.)
No I didn't. I read about it and see the usage now. However, still have some questions:
1. the man pages said not to crop while using pullup. How would I crop? I've tried to go back and crop already encoded material, but it doesn't see to work.
use mplayer -vf cropdetect and let it run for a while. Get the values and supply them to the crop filter, which you place *after* pullup, eg -vf pullup,crop ....
2. The movie Blue Streak has a framerate switch at 4650.4 & 4650.8 seconds(to 30, back to 24). It happens at an explosion in the movie. How do I account for that? Is this what pullup is for?
Yes
I don't really plan to go back and redo everything I already have unless it's a really big change. I use 2 pass XviD with 1
Thanx
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-----Original Message----- From: Grozdan <neutrino8@gmail.com>
use mplayer -vf cropdetect and let it run for a while. Get the values and supply them to the crop filter, which you place *after* pullup, eg -vf pullup,crop .... Ahh....I see. I thought it meant seperately. Thanx
Hi guys I've re-encoded some of my stuff using the -vf pullup,softskip option and have run into an anomaly. I have all 7 seasons of NCIS on DVD. I re-ripped them and re-encoded them with the recommended settings for progressive videos. The first 6 seasons are fine, and all files seem to be around the same size of about 450MB using XviD 2 pass and 1280 bitrate. However, I have some strangeness in Season 7. Some of the files are around 400MB. I verified my scripts and I have bitrate=1280 specified on all episodes. However, when I use -identify on the ones that are smaller, I get lower bitrates reported. Episode 1 gives 1014.9kbps, where episode gives 1275kbps(which is about the average of the other season's episodes). I re-ran the encode and got the same results.... Any idea why these couple of episodes are showing lower file sizes and kbps? Episode 13 - 1037.9 Episode 12 - 1085.8 Episode 19 - 1180.1 Thanx
Hi guys
I've re-encoded some of my stuff using the -vf pullup,softskip option and have run into an anomaly.
I have all 7 seasons of NCIS on DVD. I re-ripped them and re-encoded them with the recommended settings for progressive videos. The first 6 seasons are fine, and all files seem to be around the same size of about 450MB using XviD 2 pass and 1280 bitrate. However, I have some strangeness in Season 7. Some of the files are around 400MB. I verified my scripts and I have bitrate=1280 specified on all episodes. However, when I use -identify on the ones that are smaller, I get lower bitrates reported. Episode 1 gives 1014.9kbps, where episode gives 1275kbps(which is about the average of the other season's episodes). I re-ran the encode and got the same results....
Any idea why these couple of episodes are showing lower file sizes and kbps?
Episode 13 - 1037.9 Episode 12 - 1085.8 Episode 19 - 1180.1
Thanx It won't use more bits than it has to. If those episodes contain a lot of dark scenes, or a lot of scenes with more static content, or blank sky, etc. then they will be smaller. The fads and styles of TV
On 11-03-31 12:33 PM, larrystotler@netscape.net wrote: production change... herky jerky constantly moving camera action gives way to more deliberate framing and more considered camera placement. A gritty urban look might get changed to a colour drenched "futuristic" look. Bright studio lighting gives way to available light or a darker mood. All of these esthetic changes will have an effect on video compression.
-----Original Message----- From: James Hastings-Trew <jimht@shaw.ca>
It won't use more bits than it has to. If those episodes contain a lot of dark scenes, or a lot of scenes with more static content, or blank sky, etc. then they will be smaller. The fads and styles of TV production change... herky jerky constantly moving camera action gives way to more deliberate framing and more considered camera placement. A gritty urban look might get changed to a colour drenched "futuristic" look. Bright studio lighting gives way to available light or a darker mood. All of these esthetic changes will have an effect on video compression.
So you are saying that if I encode a file at like 4096 bitrate, and it doesn't need it, it will actually use a lower overall bitrate? Thanx
On 1 Apr 2011, at 04:00, larrystotler@netscape.net wrote:
-----Original Message-----
From: James Hastings-Trew <jimht@shaw.ca>
It won't use more bits than it has to. If those episodes contain a lot of dark scenes, or a lot of scenes with more static content, or blank sky, etc. then they will be smaller. The fads and styles of TV production change... herky jerky constantly moving camera action gives way to more deliberate framing and more considered camera placement. A gritty urban look might get changed to a colour drenched "futuristic" look. Bright studio lighting gives way to available light or a darker mood. All of these esthetic changes will have an effect on video compression.
So you are saying that if I encode a file at like 4096 bitrate, and it doesn't need it, it will actually use a lower overall bitrate?
That, and unless you use two-pass encoding it can also happen if just the last part is much simpler to encode and similar.
participants (5)
-
Carl Eugen Hoyos -
Grozdan -
James Hastings-Trew -
larrystotler＠netscape.net -
Reimar Döffinger