• Compression Techniques

  Noise in dark areas FCPX -> Compressor 4

  Posted by Alya Flanke on August 19, 2013 at 11:03 am

  Hello,

  I use FCPX 10.0.6 with Compressor 4.
  The problem which I am not able to solve is that whenever I export my project from Final Cut with Compressor, one dark shot always comes out with noise.
  The different grey tones (it’s in black and white shot with the canon 5d) do not seem to merge neatly but build separated zones.

  This is what it looks like:

  

  When looking at the same shot in FCPX however, it looks smooth and those lines are not there.
  This is the same shot what it looks like with Final Cut:

  

  I exported with the following settings:

  File Extension: mpeg
  Estimated size: 6.2 GB
  Type: MPEG-2 program stream
  Video Encoder
  Width: 1920
  Height: 1080
  Pixel aspect ratio: Square

  Frame rate: 24
  Frame Controls On:
  Retiming: (Better) Motion Compensated
  Resize Filter: Statistical Prediction
  Deinterlace Filter: Better (Motion Adaptive)
  Adaptive Details: Off
  Antialias: 0
  Detail Level: 0
  Field Output: Progressive
  Start timecode from source

  Field dominance: Automatic:
  Selected Progressive
  Average bit rate: 10 (Mbps)
  1 Pass VBR enabled
  Maximum bit rate: 15.1 (Mbps)
  High quality
  Best motion estimation
  Closed GOP Size: 12, Structure: IBBP

  AND

  File Extension: mov
  Estimated size: unknown
  Audio Encoder
  16-bit Integer (Big Endian), Stereo (L R), 48,000 kHz
  Video Encoder
  Width: 1440
  Height: 1080
  Pixel aspect ratio: HD (1440×1080)
  Crop: None
  Padding: None
  Frame rate: (100% of source)
  Frame Controls On:
  Retiming: (Best) High quality Motion Compensated
  Resize Filter: Linear Filter
  Deinterlace Filter: Fast (Line Averaging)
  Adaptive Details: Off
  Antialias: 0
  Detail Level: 0
  Field Output: Same as Source
  Codec Type: HDV 1080p24
  Multi-pass: Off, frame reorder: On
  Pixel depth: 24
  Spatial quality: 50
  Min. Spatial quality: 0
  Key frame interval: 24
  Temporal quality: 50
  Min. temporal quality: 0

  Maybe someone knows the problem and can help me!
  If you need any more information please let me know.

  Thanks in advanced!

  Ivan Myles replied 13 years ago 2 Members · 3 Replies
• 3 Replies

• 

  Ivan Myles

  August 20, 2013 at 5:33 pm

  Looks like banding and quantization artifacts. This behavior is inherent to high compression encoding. Here are some options:

  Encoding:
  – Increase the quality levels (I’m not familiar with HDV settings, but you might want to boost the minimum levels and maximize the upper levels)
  – enable multi-pass VBR
  – increase the encoding bitrate
  – reduce the key frame distance

  Editing:
  – add light grain or noise
  – replace the soft gradient with a texture or solid color

  Also, is the source material progressive or interlaced?
• 

  Alya Flanke

  August 20, 2013 at 9:30 pm

  Hi,

  Are the options that you suggest right for mpeg 2?

  Is multi-pass VBR the same as Two pass?
  Where do i find in compressor the key frame distance?

  Is there on the camera a precise option for shooting in progressive?
  I shoot with mark ii at 24 frame per second with pal system.
  I edited wit native camera format and the project in final cut pro it is in progressive.

  Could that be caused by an excess of Noise reduction plug in?

  Thanks
• 

  Ivan Myles

  August 22, 2013 at 4:21 am

  Note that my previous recommendations were not encoder-specific. I shall defer to other posters regarding instructions for Compressor.

  Are the options that you suggest right for mpeg 2?

  – Yes. The biggest factors will be bitrate and quality level.

  Is multi-pass VBR the same as Two pass?

  – For the purpose of this discussion, yes.

  Where do i find in compressor the key frame distance?

  – In your previous post refer to the MPEG parameter “Closed GOP Size” and the HDV setting “Key Frame Interval.”

  Is there on the camera a precise option for shooting in progressive?

  – I believe the Mark ii shoots progressive.

  Could that be caused by an excess of Noise reduction plug in?

  Anything is possible, but the most likely causes are low bitrate and quality levels.

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