Hello, 

a brief introduction of myself: I have completed about a dozen smaller
video editing project with Cinelerra since a couple of months and am
overally very pleased with program. With my fellow instructors in a
media program in an art school, I'm introducing the program into our
course and teaching it to students. (Thanks to our colleagues and
friends from CONSTANT Brussels to ultimately pointing us to Cinelerra as
a matured and viable video editing solution.)

However, in my work with the program I'm hitting the following
obstacles. I am using Cinelerra 2.1.0 in the Subversion snapshot from
20/5/2007 (Pentium M-optimized kiberpipa.org Debian package) under
Debian GNU/Linux unstable on a 1.6 Ghz, 32-bit Core Duo desktop PC with
2 GB RAM.

- Exporting 16:9 video:
  Anamorphic 16:9 video projects get exported with a 4:3 ratio as soon
  as any effects or compositing are applied, even if the "Format"
  preference is set to 16:9. The material has been properly recorded and
  captured as 16:9 PAL DV. 

- Color space issues:
  Color quality is the best using the RGBa-float color space and
  degrades to paler, slightly greenish colors when setting it to
  YUVa-8bit. But since I have the same issue when I export to QuickTime
  with uncompressed RGB and transcode to MPEG2/MPEG4 (YUV) with ffmpeg,
  it might be an issue of the color spaces, and a limitation of YUV, per
  se?

- Drag-and-drop editing behavior
  A common situation: Two clips are on the same video track, with a gap
  in between them. If one drags the left handle of the second clip
  across the gap, the behavior is not as expected: The clip doesn't
  expand to the left, but keeps the gaps and expands to the right.

- Background rendering: Background-rendered [jpeg] sequences drop frames
  in playback; I thus switched the feature off. On top of this, the
  background renderer is not very smart, re-rendering an entire track
  when only small parts of it have been changed.

- Combination of deinterlacing and slow motion: It would seem logical
  that chaining the "Frames to fields" filter and a 50% slow motion via
  "Reframe RT" would result in smooth 25fps slow motion, but this is not
  the case. My ultimate solution was to set the project to 50 fps, apply
  "Frames to fields", export as 50fps QuickTime, reimport into a 25fps
  project and set the clip frame rate from 50fps to 25fps; working, but
  not very elegant.

- Confusing settings of "Reframe RT" (video) and "Time Stretch" (audio):
  one would normally expect these filters to correspond to each other.
  However, the aforementioned slow-mo requires a "50%" setting in
  "Reframe RT", but "200%" in "Time Stretch". What's more, the audio
  filter has an impractical/imprecise analog knob widget vs. the more
  precise numerical input widget of "Reframe RT".
 
  The use of either filters results in thumbnails/curves in the timeline
  getting out of sync. The expected behavior is that clips react to the
  timing changes, and that their edges can be dragged accordingly - but
  this is not the case. Instead, both the clip handles and the brown
  effect widget have to be moved independently.

- The "white balance" option in the "Color Balance" filter doesn't work
  at all, but turns the picture green.

- Playback precision: Playback often does not stop immediately when
  hitting the space bar. Frame-by-frame stepping is not reliable; for
  example, when stepping back from the end of a video track to its
  (seemingly) last frame, stepping right reveals still another frame -
  even when the source material and the project have the same frame
  rate.

Playback performance is an issue, too - the program just feels sluggish
-, but I guess I just have to wait for lowres-dummy editing, or for
quadcore 64bit PCs to become more affordable.

Florian


-- 
http://cramer.plaintext.cc:70
gopher://cramer.plaintext.cc

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