240 fps rendering with Sony vegas pro 12 and other good Q's

[Muffdiever]

Hi everyone. I'm totally new to video editing. I've entrenched myself into reading and learning over this Xmas break and have learned a lot but have a ton more to understand that I could use experienced people's help with.

For example:

I like to take a lot of smooth slow motion vids. So I shoot with my gopro hero3 at 480p 240 fps. I open it in vegas 12, have presets match video source and start editing (slowing parts down, speeding up etc) . When I get done and want to render, I currently go to Sony avc, and customize the settings. My questions are should I want to preserve the 240 fps, or should I render in a 1080p 30 fps or other option? How does what I render to affect my slow motion quality, if at all? Should I render in 480p? If so I cannot find an 848x480 setting, nor can I find a 240 fps setting.

So in summary, do I need to render 480p 240 fps source footage to the same specs to preserve the slow motion quality?

PS: Some side question? What is the point of a velocity envelope if it reduces (in the case of slowing a clip down) the amount of the clip that I see. If I want to show the entire clip in slow motion velocity seems useless. If I have 240 fps and my goal is to play at 10% speed and then render in 24 fps so it matches I cant figure out how I would do that. Velocity cuts it short. Playback rate only slightly above .1 and if I stretch it I can't tell the percentage I slowed it down. I also can't find an alternative to stretching where the audio gets slowed down as well. Playback rate and velocity seem to not affect audio at all. But stretching does.

A lot of questions, but anxious to learn. I read somewhere that I should up res my go pro vids before editing. Don't even know how to up res and if I could use vegas 12 to do that. Thanks in advance!!

[_Al_]

load your 240 fps clip into VirtualDub and change fps to 30, export lossless or uncompressed and load in into Vegas , 30p project

or within Vegas
-Velocity envelope can slow down your clip,
-CTRL + drag right end of your clip to the right, you can stretch it only 4x

you can combine those last two but it will give you headache to keep certain start and end of your clip an also you have to carefully calculate to get final fps so Vegas will not have to blend fields,

better to do it quick in VirtualDub

I just notice, checking Vegas, thinking it cannot be that it is so lame to work with slo-mo, ...., there is "playback rate" and "undersample rate" within properties for the clip (right clip/properties) so definitively try that !

[jagabo]

The camera shoots at 240 fps but the files it produce are marked for playback at 30 fps (or maybe 60 fps). That's why they play back in slow motion. Otherwise the software would attempt to play them at 240 fps and the video would appear at normal speed on the screen.

[deadrats]

The camera shoots at 240 fps but the files it produce are marked for playback at 30 fps (or maybe 60 fps). That's why they play back in slow motion. Otherwise the software would attempt to play them at 240 fps and the video would appear at normal speed on the screen.

with 3d the refresh rate of the monitor acts as the limiting factor of how fast a scene can be displayed, so lets assume you're playing a game and the internal frame counter says your system is rendering at 240fps, the screen can only display at the refresh rate (in my monitors case 60fps) and the rest gets queried to the back buffer, then the frame buffer and as the backlog builds up frames just start being drop (or else you would run out of video memory and eventually system memory.

doesn't a similar thing happen with video? in other words if one was to try to view a 240fps movie on a high end monitor that could do 120hz, would frames eventually start being drop, resulting in a choppy playback? would the media player freeze up, basically i'm wondering if it's even possible to view 240fps video smoothly, with no dropped frames or choppy playback, on regular consumer monitors and tv's?

[Muffdiever]

Thanks guys. So two things. One, is to the first reply. Why doesn't rendering in Vegas to 30fps do the same as virtualdub?
2nd is for 2nd reply. The 240 fps clip I take with gopro does play in 240. It is normal speed. If I render as is in Vegas to 1080p 30fps, it still plays at normal speed. Need to use velocity and or playback rate.

So to not have Vegas do the work I have to calculate that if it is 240 footage I can only play at 10% speed at 24 fps. Right?

[jagabo]

2nd is for 2nd reply. The 240 fps clip I take with gopro does play in 240. It is normal speed.

Odd. The high speed videos I've seen are marked as lower speed.

One, is to the first reply. Why doesn't rendering in Vegas to 30fps do the same as virtualdub?

In VirtualDub you can tell the program to assume the frame rate of the source is 30 fps (or whatever frame rate you want) rather than 240 (or whatever it actually is). Your 240 fps source will play back in slow motion at 30 fps. Or you can have it decimate frames to change the output frame rate. In that case the action will play at normal speed but at 30 fps (ie, 7 of every 8 frames of the source will be discarded).

I don't know exactly what Vegas does.

So to not have Vegas do the work I have to calculate that if it is 240 footage I can only play at 10% speed at 24 fps. Right?

Yes. Changing the source frame rate from 240 to 24 will give you 1/10 speed.

[Cornucopia]

I'm pretty sure that, assuming the 240fps really was "interpreted" as 240, Vegas would either straight decimate to the project's (and/or render's) framerate, or would do an interpolated/blended decimate. It would only slo-mo if those other parameters (velocity, playback rate) were changed.

Vdub (and AVISynth) is primarily a processor, and as such it works with the incoming framerate (until you tell it differently), whereas Vegas (Premiere, etc) are primarily NLEs and work according to the project (and/or render) framerate, interpreting the incoming as it can (unless otherwise specified).

Scott

[_Al_]

I have to calculate that if it is 240 footage I can only play at 10% speed at 24 fps. Right?

I'd try
for 30p project, change playback rate to 0.125 to get 30p and slow-mo, then drag right end of a clip to the right to stretch it fully
for 24p project, change playback rate to 0.1 to get 24p

not sure how resample behaves here, better to disable it for this clip I think (right above "playback rate")

[poisondeathray]

doesn't a similar thing happen with video? in other words if one was to try to view a 240fps movie on a high end monitor that could do 120hz, would frames eventually start being drop, resulting in a choppy playback? would the media player freeze up, basically i'm wondering if it's even possible to view 240fps video smoothly, with no dropped frames or choppy playback, on regular consumer monitors and tv's?

Yes it does. But you know there are commonplace 600Hz consumer displays now, right ?

And it's rare to view a 240fps movie at 240fps. People use typically higher framerates for slow motion

The "choppiness" comes when you have non evenly divisible multiples of frames displayed, so a frame might be displayed fractionally longer than others . When you get to higher range of FPS, the effect isn't as noticable . This is what some people might percieve as "stuttering" even though the minimum frame rate might never drop that low . There are a bunch of articles on tech sites in regards to GPU's and video games on this topic if you search (they compared Nvidia cards and AMD cards with high speed camera to see the stuttering)

[jagabo]

But you know there are commonplace 600Hz consumer displays now, right ?

No there are not. The 600 Hz sub-field spec in plasma displays (if that's what you're talking about) is not the number of frames per second being displayed. Even the 120-240 Hz LCD displays do not accept 120-240 Hz input.

On a typical computer display set to 60 Hz output, and a player with VSync enabled, you will only see every 4th frame of a 240 Hz video. If you disable Vsync you will get 4 tears in the picture.

[poisondeathray]

not sure how resample behaves here, better to disable it for this clip I think (right above "playback rate")

At even multiples , it will take whole frames e.g. 1/10th of 240 is 24

The resampling setting takes effect when he ramps speed changes. The "inbetween" frames are either blends (smart resample on), or duplicate frames (resample off).

[poisondeathray]

But you know there are commonplace 600Hz consumer displays now, right ?

No there are not. The 600 Hz sub-field spec in plasma displays is not the number of frames per second being displayed. Even the 240 Hz LCD displays do not accept 240 Hz input, or even 120 Hz input.

Yes you're right, HDMI spec doesn't go that high

What does that figure represent ? duplicates ?

[jagabo]

Plasma manufacturers are very evasive when discussing exactly what the number means -- they just want to advertize a number that's higher than LCD's 120-240 Hz number. As near as I can tell, the 600 Hz sub-field spec of plasma TVs is the number of times per second the signal is electrically pulsed to the display. When a plasma element receives and electrical pulse it glows for a short period of time, then fades (much like the phosphors on a CRT). To reduce flicker and increase brightness, the elements are pulsed at a rate higher than the displayed frame rate. So a 60 Hz display is pulsed 10 times per frame to give a 600 Hz sub-field number. But there are not 600 different pictures being displayed. Actually, I think it's less than that because the display is broken up into bands and each region is pulsed individually (probably a matter of power consumption). So if the display is split into 5 bands each band is pulsed twice per frame (120 Hz).

[Muffdiever]

I have to calculate that if it is 240 footage I can only play at 10% speed at 24 fps. Right?

I'd try
for 30p project, change playback rate to 0.125 to get 30p and slow-mo, then drag right end of a clip to the right to stretch it fully
for 24p project, change playback rate to 0.1 to get 24p

not sure how resample behaves here, better to disable it for this clip I think (right above "playback rate")

Thanks Al. Please clarify if you can:

If I right click on clip and change playback rate it doesn't allow the audio to play at this same rate. Only if I stretch does it allow me to do this. How do I solve that? Now the clarity part. Since .125 would bring me in alignment with 30p why do I then need to stretch it fully? And as for .1, vegas doesn't allow me to adjust playback rate to .1. To play at 10% i would have to use a velocity envelope.....but then if i did set that envelope to 10% speed, it would also reduce my clip by 90%. I don't know the best way to achieve playing at .1, having it not reduce my clip size, and having the audio slowed down to 10% as well.

[_Al_]

ok, I see it doesn't allow to set playback rate that low,
so for 30p you use CTRL+drag to just strech it 4x and then you use velocity to 50%:

details if you are not sure:
-click on the clip, place cursor at the end, CTRL+C, CTRL+V 3times, press "M" (make mark),delete those copies of a clip you just made
-press CTRL and drag the end of clip to the mark (4time strech,..., coincidentally 4x is a maximum anyway so you could skip that above process of making that mark)
-select that clip, make sure the cursor is at the end ,Ctrl+C, Ctrl+V, press"M", delete that copy of your clip you just created
-insert Velocity , set 50% - RIGHT click on the first point and , set to .., manualy input 50,
-drag the end of clip to the mark (do not press CTRL at the same time, this time you are not stretching, you just reveal that slowed down clip further)

this will slo-down your clip to exactly 12.5%


For 24p, you use CTRL+drag to just stretch it 4x also and then you use velocity to 40%

in both cases you should have exactly one unique frame of you original for your new video,
if you start to change numbers to your liking some interpolations or dropping frames will occur, but Vegas in not bad to do this, so results might be ok too, maybe this fuss is for nothing really,..

[Muffdiever]

ok, I see it doesn't allow to set playback rate that low,
so for 30p you use CTRL+drag to just strech it 4x and then you use velocity to 50%:

details if you are not sure:
-click on the clip, place cursor at the end, CTRL+C, CTRL+V 3times, press "M" (make mark),delete those copies of a clip you just made
-press CTRL and drag the end of clip to the mark (4time strech,..., coincidentally 4x is a maximum anyway so you could skip that above process of making that mark)
-select that clip, make sure the cursor is at the end ,Ctrl+C, Ctrl+V, press"M", delete that copy of your clip you just created
-insert Velocity , set 50% - RIGHT click on the first point and , set to .., manualy input 50,
-drag the end of clip to the mark (do not press CTRL at the same time, this time you are not stretching, you just reveal that slowed down clip further)

this will slo-down your clip to exactly 12.5%


For 24p, you use CTRL+drag to just stretch it 4x also and then you use velocity to 40%

in both cases you should have exactly one unique frame of you original for your new video,
if you start to change numbers to your liking some interpolations or dropping frames will occur, but Vegas in not bad to do this, so results might be ok too, maybe this fuss is for nothing really,..

Hmm. I tried this earlier today, So For 24p or 30, why wouldn't we just set the envelope at 10% (.1 x 240 fps = 24) or the 12.5% for 30p, and not stretch/play around with playback rate at all? Curious

My reason i dont even use velocity in this case is I want the audio to be slow as well and match, which velocity doesn't allow you to do. So hitting control and stretch/drag has been my only option except the limit hits a playback rate of 25% (4x) not 10% like I need.

I even tried saying screw the audio and let's go to properties, do 40% on the playback rate, and 25% on the velocity envelope, which should get me to 24p. Here is a problem I saw. The clip which is 58 secs should be 10x longer at 10% ( 9min 40'). But actual I had to extend it to 9around min 30'. Something is off and I don't think it is my math....could be..Correct me if I'm wrong. Try testing that out if you can and see if vegas shows it correctly. Do need to figure out how to make the audio slowed that much as well..

Thanks for the time on this and all worth the fuss! ; ) hate not knowing how to do something. Had someone say today that up res'ing the gopro video and then editing is the best way to edit. Now have to figure out what upresing exactly is, why it is done, and what tool do I need to do it and how do I do it with that tool. Jeez..

[_Al_]

for some reason I thought that I cannot input 10% for velocity,

you can use audacity, to slow down audio and keep pitch,I just google it quickly, http://acapella.harmony-central.com/showthread.php?2772355-Audacity-Slow-down-songs-but-keep-pitch

or just do it couple of times in Vegas - slowdown 4x - lossless export, import and again slow-down again ...
or you can load vegas project , *.veg (4time slow-mo) into another project , try that ...