+ All Categories
Transcript
Page 1: Stefan slivinski lifesize video coding

1 © 2014 Lifesize, a division of Logitech. All Rights Reserved. Confidential.

Video Coding: Current and Next

Generation

Stefan Slivinski

Distinguished Engineer

Lifesize Communications

Page 2: Stefan slivinski lifesize video coding

2 © 2014 Lifesize, a division of Logitech. All Rights Reserved. Confidential.

Overview Video Coding – Past, Present and Future

“Pretty Soon We Wont Need Video Compression”

Page 3: Stefan slivinski lifesize video coding

Video Compression

Past, Present and Future

Page 4: Stefan slivinski lifesize video coding

4 © 2014 Lifesize, a division of Logitech. All Rights Reserved. Confidential.

Types of

Compression

Lossless

• Original information

is recoverable

Lossy

• Information is lost

Not specific to Video

Compression

Page 5: Stefan slivinski lifesize video coding

5 © 2014 Lifesize, a division of Logitech. All Rights Reserved. Confidential.

Lossy Video

Compression

Incapable of seeing high

details

More sensitive to light

than it is to color

can only fully perceive

about 15fps

Exploiting the

limitations of the human

visual system

Page 6: Stefan slivinski lifesize video coding

6 © 2014 Lifesize, a division of Logitech. All Rights Reserved. Confidential.

Video

Compression

Spatial compression

Temporal compression

Discrete cosine

transform (DCT)

Quantization (lossy)

Entropy coding

It’s all pretty similar

Page 7: Stefan slivinski lifesize video coding

7 © 2014 Lifesize, a division of Logitech. All Rights Reserved. Confidential.

Video

Compression Macroblocks

Spatial and

Temporal

Quantization

Entropy coding

Past

H.261 (1988)

MPEG-2 (1995)

H.263 (1996)

MPEG4 Part 2 (1999)

Page 8: Stefan slivinski lifesize video coding

8 © 2014 Lifesize, a division of Logitech. All Rights Reserved. Confidential.

Video

Compression

Multiple intra prediction modes

Up to 16 motion vectors per

macroblock

4x4 and 8x8 fixed point transform

Multiple block sizes include non-

square blocks

Adaptive Inloop deblocking filter

Arithmetic entropy encoding

Halfpel and quarterpel pixel

interpolation

Present

H.264 / MPEG-4 AVC

(2003)

Page 9: Stefan slivinski lifesize video coding

9 © 2014 Lifesize, a division of Logitech. All Rights Reserved. Confidential.

Video

Compression

Very large block sizes (up to

64x64)

4 transforms sizes 4x4, 8x8,

16x16, 32x32)

coding tree units (CTU)

Parallel processing tools adapted

to multicore or hardware

architectures

Bit depths beyond 10bit, full

chroma (unsubsampled)

Future

H.265 (2013)

Page 10: Stefan slivinski lifesize video coding

“Pretty Soon We Won’t Need Video Compression”

--some guy I saw at a trade show

Page 11: Stefan slivinski lifesize video coding

11 © 2014 Lifesize, a division of Logitech. All Rights Reserved. Confidential.

Need to answer

3 questions

How much resolution is

enough?

How much

compression is

enough?

How much bandwidth is

enough?

Page 12: Stefan slivinski lifesize video coding

12 © 2014 Lifesize, a division of Logitech. All Rights Reserved. Confidential.

How much resolution is enough?

Page 13: Stefan slivinski lifesize video coding

13 © 2014 Lifesize, a division of Logitech. All Rights Reserved. Confidential.

How much

resolution is

enough

The average human eye can resolve 300 pixels per inch (ppi) at a distance of 12 inches

The first retina iPhone (iPhone 4) had 326ppi

A 60” 4K television

• Has a ~73 ppi

• THX recommended viewing distance of 6-9’

• At 6’ the average human can resolve 40 ppi

• You would need to sit at a distance of 3.25’ (39 inches) or closer to see all 73 ppi

Page 14: Stefan slivinski lifesize video coding

14 © 2014 Lifesize, a division of Logitech. All Rights Reserved. Confidential.

How much bandwidth /

Compression is enough?

Page 15: Stefan slivinski lifesize video coding

15 © 2014 Lifesize, a division of Logitech. All Rights Reserved. Confidential.

Availability of

bandwidth

20-30mbps in developed

world

Developing World much

further behind

Page 16: Stefan slivinski lifesize video coding

16 © 2014 Lifesize, a division of Logitech. All Rights Reserved. Confidential.

Video

Compression 4Kp30 bandwidth

• H.265: 2-4mbps

• H.264: 4-8mbps

• MPEG4: 8-16mbps

Video Communication

Content

Page 17: Stefan slivinski lifesize video coding

17 © 2014 Lifesize, a division of Logitech. All Rights Reserved. Confidential.

How big is

uncompressed

video?

4Kp30

• 3840 x 2160 @ 30fps @ 422

• 3.9 gbps uncompressed

720p60

• 1280x720, 60 fps @ 422

• 844 mbps uncompressed

CIF resolution

• 352 x 288 @ 30fps @ 422

• 48.6 mbps uncompressed

QCIF resolution

• 176 x 144 @ 30fps @ 422

• ~12 mbps uncompressed

Page 18: Stefan slivinski lifesize video coding

18 © 2014 Lifesize, a division of Logitech. All Rights Reserved. Confidential.

Conclusion Television resolution

peaking

Bandwidth still poor

Compression peaking in

developed world

Page 19: Stefan slivinski lifesize video coding

Questions?


Top Related