Double Frame Rate to Eliminate Staggering on Camera Fly by

[Adam Trachtenberg]

It isn’t clear to me if the stuttering is caused by the playback device as opposed to the actual frame rate. I’d load the uncompressed frames into AE and see what it looks like under RAM preview.

[Douglas Kerr]

Hey Adam,

thanks for getting back to me. I imported two RPF sequences at 50FPS and 25FPS into After Effects. The 25FPS looked just the same whilst the 50FPS looked better but not perfect. Yet I know I’ve had smoother camera fly pasts out of After Effects.

I tried adding motion blur in C4D but it seems to take alot of fine tuning.

It doesn’t seem to be a frame rate issue but that’s as far as I’ve got.

any ideas?

[Douglas Kerr]

I’ve done lots of renders now in 25fps,50fps,60fps and slowed down the camera move and it is still juddering badly.

I’ve been rendering uncompressed Animation QTs and some have been watching through Quicktime some ok but others getting 2 sec lag between judders mid-way through clips.

I’ve also tried H264 but no better

Could it be a quicktime data stream issue?

VLC shows a frozen screen with ‘error ocurred’ late video..more than 5 secs of lag..etc.

[Adam Trachtenberg]

It does sound like a QT issue, or possibly hardware. Hard to say….

[Brian Jones]

What’s the hardware you are trying to play back on? CPU? Graphics card? How much memory?
What is the resolution of the render?

Your link plays pretty smooth here (full screen 1920×1200). But a lot of things affect playback, if the res/file size is too big you need fast bus/mem/hd if you compress to bring down file size you have to watch which codec since almost anything that compresses really well is processor intensive, some are better than others for decompress speed (I’d have to look it up) so here CPU speed is important… So how big is this beast?

Have you tried putting it to DVD – check out playback on a purpose built device?

[Douglas Kerr]

thanks guys, I checked on a cheap domestic DVD player, looks much the same as playback through Mac. Which means its not a playback issue, must be in the render stage or before, is that right???

I’m am running a
2 x 3GHZ Dual Core Zeon Mac Pro,
8GB 667MHz DDR2.
NVIDIA GeForce 7300 GT.
SATA 2 (16mb cache I think) 750GB drive

The renders are 1280 x 720 Progressive, QT Animation codec.
The data rate for a full render is showing 495.78.mbits/Sec. 2:10 duration / 7.79 GBs

Is it possible you can achieve different results from the hardware you use to render out??? I thought it only effected time taken to process.

Is there an effective way to test what the max data rate my system can handle??
(better than this way I mean!!)

Anyone know of a good online guide to video codecs?

thanks again.

[Douglas Kerr]

I’ve posted 2 examples of rendered clips. (file size 25MB)

https://www.yousendit.com/transfer.php?action=download&ufid=Y2o4UGhYTWNxRTJ4dnc9PQ

If anyone could tell me their opinion, that would be great..

[Brian Jones]

Animation codec that big is going to have trouble playing off anything. The SATAII bus is plenty fast but 62 MB/sec (496/8) is right in the range between min and Max sustained transfer rate for most 7200 rpm drives and those numbers are generated under perfect conditions with non-fragmented data, which this almost certainly is. So for the perfect quality Animation version expect it to not play back smoothly.

For compressed versions your processor should be fast enough, I don’t have enough knowledge of video cards to know if the 7300 is quick enough for that but it probably is.

I have the 8 core 2.8 Mac with an ATI 3870 and the HDV 720p 25 plays smoothly though I do see a slow down at the end of the 1st Calvin Klein it looks like the spline the camera is following is not set to Uniform, not a missed frame (or frames) in playback. That’s with VLC for playback and VLC won’t play the second test (I don’t have the full suite of codecs here at home – I assume I’m missing some of the FCP codecs)

The best guide I knew of is gone, though siggraph’s codec central here – https://www.siggraph.org/education/materials/HyperGraph/video/codecs/Default.htm – has some info though it’s getting seriously dated now. There are probably others I don’t know about, anybody?

[Brian Jones]

A couple things I should have thought of yesterday

– if you step through the Animation codec version frame by frame is it still jerky?
– what did you use to compress to DVD and what were the settings? With that much motion you’d want to keep the mp2 at not too high a bitrate

[Douglas Kerr]

Thanks Brian,

The real problem is still uncertain.

I think it was a combination of trying to render out using unrealistic Animation codec settings and unrealistic expectations of a fast and sharp render at 25FPS.

I have rendered out DVCPROHD 60FPS and it plays nicely with the 30FPS footage I have tested it with in After Effects.

I’m still experimenting with different renders so maybe i’ll discover other contributors

When I step through frame-by-frame I can see very noticeable movement.