I am trying to understand the way in which Movie Studio ( v12 Platinum) deals with high fps. So for example I can shoot at 25fps, 50fps, 100 fps. If I play any of that footage on my PC it plays at normal speed. If I import any of that into the MS timeline ( 25fps project) , it plays at normal speed. I have a couple of ways to create slowmo using these faster framespeeds...either transcoding in cineform and changing the framespeed to create a slowmo clip which I then import to MS , or if I import my cam output direct to MS I can rubber band.
I assume playback on my PC is at the framerate of the clip...therefore it plays at normal speed.
My question is how does MS deal with that faster framerate? Is it dropping frames.....e.g for 50fps footage dropping every other frame....or maybe selecting 25 frames with a little more intelligence than that? What happens if that clip is then rubber banded? Are some of the missing frames then reinserted?
I am happy with how I handle faster framerates within MS. If I transcode using cineform I leave the original framerate as is, (unless I am creating a slowmo clip), and regardless whether that is 50 or 100 fps, MS just deals with it, even if there is a mix of those framerates. Very impressive. But I would like to know what techniques it is using and whether those techniques are common to the main NLEs or whether MS has a different approach.
I don't know, but afaik there are only 2 ways convert 50fps footage to 25fps. Either:
a) drop every second frame, or
b) create new frames by blending together adjacent frames.
One way to determine what actually occurs would be to start with footage where each frame is clearly numbered. Then, do what you want (e.g. loading a 50fps footage into a 25fps project; or using the slow motion effects), and finally re-examine the output.
To make this easier; you may want to use these two test videos. Simply download them and use them for your tests. www.tima.uk.com website
What your taking about is called pull down, if you Google this term you will see there are standard pull downs for different frame rate conversions. Like 30fps to 25 fps etc. Like Tim I presume a 50 to 25 will take out every other frame but I'm not an expert is these matters. Just make sure you disable re sample when you go from 50 to 25 fps as you should get better results.
Thanks both. I ran the test and the answer is that Movie Studio blends frames.....so in the test one clip was 300 frames at 50fps, the other 300 frames at 25 fps. Import both to
a 25 fps project.
Preview of the 25fps clip is predictable......300 individual frames.
Preview of the 50 fps clip was converted to 150 frames each containing 3 frames ( except the first). So frame numbering was:-
01 123 345 567 789 and so on.
I am encouraged by this since it means no frames are lost, so if the timespan is increased to create slowmo, those extra frames are available.
I am now wondering what technique Gopro Cineform Studio uses! I typically use that to create slowmo because it gives me the ability to select a greater range of slowmo than the 4x in Movie Studio.
I also transcode all my other footage to Cineform avi so it means I have a common format that I am importing. I do leave the framerate as per original in cineform however except if I need slowmo....and
the above test seems to confirm that is the best workflow.
I cannot answer the question posed by mikerb, but it's a fact that NLEs and indeed movie cameras don't (cf Cinecamera), record actual frames, except every-so-often, with in-between "frame data" amounting to the picture difference. The actual technique will depend on the nature of the compression, since it is this objective that is used to enable us to get so much stuff on a tiny memory-card.
All of those software programs use techniques which understand this and must juggle the full-frames and the inbetween "frames" - what I'm quite unclear about is the mechanism used by Sony Movie Studio, as this appears to have a limited range of speeds - I wonder if that is simply to address the Enthusiest Market and provide differentiation with the Vegas "Pro" software.
This situation is about to change when BlackMagic (style) cameras become the norm. For I understand these do record complete frames, presumably because the SSD memory used has much greater capacity (than SDHC cards) . . . . or perhaps it's just SSD is far more convenient in Pro circles. With full frames "in the can" it is possible to urtilise compression (or not) on the basis of the effects demanded by Production.
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Last edited by vidmanners; 04-02-2013 at 01:09 AM.
Yes...goodness know what exactly happens in h264 encoding but my quest started when I wanted to know how best to treat 50 fps ( progressive) footage. A previous thread on here and another forum answered that for me. Both 50fps and 100fps outputs from my camera pose no problems to Movie Studio.
I transcode everything in Cineform before importing to Movie Studio but I leave framerates as they are originally. They go into a 25p project and provided resample is disabled, the results are brilliant both in preview and in render. It seems however that simply importing 50 or 100 ( 60 /120) into other NLEs like Adobe Premier, results in the footage playing in slow motion.....I am no expert on Premiere but it appears you have to create a sequence and tell Premiere what fps is being imported in order to prevent that happening. SV1 AP 0!.
The Cineform codec produces avi at a much lower compression than h264 so how the real and infil frames are then made up is anyone's guess!! That is my next test.....to see what happens to 50fps avi footage in MS....will it be the same triplet technique???