Mobile Content Processing

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Mobile Content Processing

• David Brooks
• VP Systems Architecture
• Snell Wilcox

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Mobile Customer Satisfaction

• The quality of the mobile viewing experience is
  determined by
• the editorial decisions made in producing the
  content for the small screen
• the fluidity of the motion
• the consistency of image quality / lack of
  compression artifacts at the low bitrates needed

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TV is also Changing BUT there are Conflicting
Drivers
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Content Creation is Changing

• In a 43 TV production, the camera tracks the
  action (e.g. ball, skater etc)
• But more and more content creation is moving to
  HDTV 169
• In 169 productions, the director lets the action
  run through the screen
• As a result there are many more wide shots which
  are great for high resolution 169 displays, but
  not so good for small screens like mobile phones

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Best Mobile Practice

• Live Content - Sports
• Use an additional camera, mounted above the
  broadcast camera, but taking tighter shots
• Additional camera height changes the angle of the
  shot, so the background is grass, not crowds
• Add second production team to re-cut live show on
  the fly
• Tighter shots, special graphics etc

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Benefits

• Both techniques reduce the percentage of the
  screen occupied by any background crowd, the
  random nature of which is difficult to compress
• This allows the limited bandwidth available for
  streaming to mobile phones to be put to best use
  by more accurately portraying the sport action
• Downside
• The additional cost of extra people and
  production hardware required for mobile version

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Helios Mobile Content Processor

• Uses SW technologies to create a mobile content
  processor
• Reduce noise (and compression artifacts)
• Dynamic re-framing
• Intra-image adaptive pre-processing
• Stabilise the image
• Flo-mo processing for smooth motion
• Compress to MobileTV specs

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Helios Dynamic Re-framing
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Helios Mobile Content Processor

• Automatic Dynamic Re-framing

No Processing
Mobile Phone 176 x 144
SW Re-frame
SDTV Image 720x576
(images to scale)
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Helios Mobile Content Processor

• Intra-Image adaptive pre-processing

Image Analysis
Input
Area of Interest Switching Mask
pre-processed output (exaggerated to show
principle)
Filtered version
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Helios Mobile Content Processor

• So far we have optimised the spatial
  characteristics of each image for easy
  compression
• The final step is to optimise the temporal
  characteristics of the image sequence
• by removing undesired jerky movements by image
  stabilisation (long camera lenses, poor panning)
• by using Flo-mo technology to produce a smooth
  motion sequence matched to the capabilities of
  the mobile TV video compressor.

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Flo-mo smooth motion processing
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Mobile Content Processor

• Encoding to H.264 _at_ 256Kb/s 15fps

Reframe
Pre-process
H264 Enc Dec
H264 Enc Dec
SW Mobile Content Processor
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Mobile Content Processor

• Encoding to H.264 _at_ 128Kb/s 15fps

Reframe
Pre-process
H264 Enc Dec
H264 Enc Dec
SW Mobile Content Processor
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Mobile Content Processor

• Encoding to H.264 _at_ 64Kb/s 15fps

Reframe
Pre-process
H264 Enc Dec
H264 Enc Dec
SW Mobile Content Processor
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Thank youAny Questions?

• To see the moving images
• visit the SW Booth - SU156
• or the Advanced Content Delivery Showcase
• in the South Hall