Archive for the ‘SmoothCam’ Category

NLE Adulteration of Source Media: Potential Workflow-Issues

Friday, September 13th, 2013

I highlighted in (10 months ago) that Adobe Premiere etc. can adulterate media files, in terms of metadata and/or sidecar-files (depending on user-configurations of these applications.  I indicated that, regardless of the reasonableness of at least some of these actions, this could potentially cause problems to other applications.

Validating that concern, I note a post (2012-06-12) by Matt Davis on Philip Bloom’s website, stating (my italics):

  • …if sharing assets with FCPX and Adobe Premiere, Adobe ‘touches’ (resets the modification date) of each file without doing anything else to it, but also sprinkles sidecar files into directories of transcodable files for metadata, thus sending any returning FCPX activity into a tailspin, requiring a re-linking session. It’s oddities like these which haunt the implementation of FCPX in a wider system and make system managers wonder if FCPX is actually worth implementing in its current state.

That was over a year ago, and so the issue may or may not exist for the current version of FCPX.

As users, whether or not the actions of one application adhere to standards and another don’t, what we as users ultimately care about is workflow, which in this case translates to “does it connect up with my other tools/processes?”.  So we have to maintain a “situational awareness” of potential interoperability pitfalls.

Incidentally, I recall that FCPX’s predecessor (in history at least, if not development-line) FCP7 could adulterate source directories with its own sidecar files, produced by its SmoothCam effect.  Not knowing anything further for sure, I nevertheless wondered (at that time) what it might be doing “under the hood” of the QuickTime [.mov] wrapper.

Glide-shots: Steady-Shot / Smooth-Deshake-Stabilize / SteadyCam

Sunday, July 25th, 2010

Which is best?   Depends on the camera, scene and shot dynamics I guess.  The same point is queried at the following thread:

Some general advice from a computer-post-savvy author: definitely use the camera’s SteadyShot:

Limitations of post

  • Stabilization necessitates motion estimation and image reconstruction, which are extremely CPU-heavy, hence really slow to execute.
  • Most stabilization apps (in post) can’t currently cope with motion-blurred edges or parallax effects (though both should be possible in principle, by deconvolution and 3D modelling both informed from multiple frames).
  • For rolling-shutter-ed footage (e.g. CMOS sensors as in Sony Exmor as in Sony XDCAM-EX e.g. EX1 & EX3), there exist options to reduce the effect (don’t expect perfection, but may suffice):

My experiences:

  • Stabilizing Tools:
    • Gunnar Thalin’s Deshaker works really well.  And it is multi-threaded, really speeds up the process.  The author says it is more intended for handheld pans etc. than fast-shaking shots from vehicles etc. (but has nevertheless seen good results in such situations).
      • The author says [] to try “to stabilize only on the most distant parts in the frames, since the moving inwards-effect is less there”.  And “you should probably increase the value for [discard motion of blocks that move > X pixels in wrong direction]. That’s to allow the blocks to move “freely” a little, since Deshaker can’t handle the “moving inwards”-effect.
      • Possibly equally applicable to other smooth/stabilize/deshake tools ?
    • Boris’s Optical/Motion Stabilizer (in Boris Red 4.3.3 on XP) is only single-threaded and I find it slower, clunkier and less intuitive than Deshaker.  Has a Smooth mode, which is like the others here, as well as a Stabilize mode (try to keep frame static, no good for motion then).  The other tools can be configured to do the same thing.
    • Mercalli in Sony Vegas has no mode for 720p50 but otherwise is pretty good and very intuitive and configurable.
    • FCP’s SmoothCam Effect worked best for a challenging clip for wobbly-hand-held camera tracking close past an object (a Formula-1 car) hence huge degree of moving-inwards effect.  The default settings worked straight away.  The result quality was way above that of the other tools.  On the other hand sometimes it’s not the best (sorry, forgot the exact situation).
  • Cameras & Shots:
    • Historically, using a TRV33 DV HandyCam indoors (hence low-light hence long shutter time):
      • Way back in the past, using a (now ancient) TRV33 DV handy-cam (which has huge sensor margin i.e. spare pixels), when I shot big zooms to lecture audience individuals (e.g. question-time) I had the camera’s steady-shot (digital, not mirror) enabled  and used Gunnar Thalin’s Deshaker (VirtualDub plugin) also.  The result was astoundingly steady.
      • The same arrangement worked OK with hand or shoulder mounted cam for walk-throughs past nearby objects (e.g. walls, people, furniture).
      • An attempt to do the same thing without steady-shot enabled on the camera resulted in seriously motion-blurred edges.
    • Now, using a Sony EX3:
      • With camera Steady-Shot set to Medium, hand-held pans and motion past nearby objects seem to acquire a positional instability, as if the camera feedback mechanism needs greater damping. Maybe the camera’s internal mirror “suspension” has to be tighter (than the TRV33 digital equivalent) because it lacks the generous pixels margin of the TRV33?  or maybe something to do with the mirror’s inertia?  Or (real-time-constrained) processing-power?
        • Experimentation is needed with the camera’s other SteadyShot modes (High, Low).
        • In the absence of more generous sensor pixel margins, I wish it could be loosened-up e.g. to allow black borders (to crop in post) so as to permit smoother rides overall.