“Comparison of H.264 and VC-1”的意思、由来-开放百科全书

H.264 and VC-1 are popular video compression standards gaining use in the industry {{as of|2007|lc=on}}.

Overview

VC-1

H.264

Goals

Designed to offer very high image quality with excellent compression efficiency^[1]

date=March 2008}}

Example industry use

Supports 4:2:0 compression / color space^[2]

Supports studio archiving requirements with 4:4:4 color space;
separate black and white (BW) video mode

Licensing costs

Similar^[3]^[4]^[5]

Documentation

Not free. Reference decoder, comes with external documentation.

?^[6] AVC/H264 Licensing costs and terms from MPEG LA.^[7] Reference encoder and decoder free as well.^[8] Additionally, JVT & M4IF mailing lists are available where one may receive answers on AVC related questions.

Terminology

All sources for the below information are from the respective specifications listed in the overview section.

Feature

VC-1

H.264

Partition sizes

16×16 and 8×8^[9]

16×16, 16×8, 8×16, 8×8, 8×4, 4×8, and 4×4

Integer transform

8×8, 4×8, 8×4, and 4×4

4×4; 8×8 available in High Profile only

Frame

Used for progressive or interlaced content

Macroblock sizes

16×16 only

Motion vector

Two dimensional vector offset from current position to reference frame

Picture

A field or frame

Skipped macroblock

No data is encoded for macroblock

Features

VC-1

H.264

Bitstream formats

single bit stream

NAL and byte stream

Bitstream format

In advanced profile, each Bitstream Data Unit has its own header.
Simple and Main profile provide neither sequence nor entry point headers.

SPS (sequence parameter set),
PPS (picture parameters set),
slice header, macroblock

Deblocking filter

In-loop filter and overlap transform

In-loop only

CABAC

Only supported in Main and higher profiles

Variable transform size

Yes

Only in High profile and above

Slice

Contiguous (integer number of macroblock rows only)

Contiguous or non-contiguous

Sub-pixel interpolation methods

bicubic, bilinear

6-tap filter for half pixels; averaging for quarter pixels

Variable Length Coding

Yes

B frame used for predicting other pictures

Yes

References

1. ^{{cite web | url = http://www.microsoft.com/windows/windowsmedia/howto/articles/vc1techoverview.aspx#Conclusion | title = VC-1 Technical Overview | first = Jay | last = Loomis |author2=Mike Wasson | publisher = Microsoft }}
2. ^{{cite book | title = SMPTE421M: SMPTE Draft Standard for Television | work = SMPTE Standard for Television: VC-1 Compressed Video Bitstream Format and Decoding Process | author = SMPTE Technology Committee C24 on Video Compression Technology | date = 2005-08-23 }}
3. ^{{cite web | url = http://www.mpegla.com/vc1/vc1web.ppt | format = PowerPoint | publisher = MPEG LA | title = VC-1 Patent Portfolio License Briefing | date = 2007-11-05 | deadurl = yes | archiveurl = https://web.archive.org/web/20070927035059/http://www.mpegla.com/vc1/vc1web.ppt | archivedate = 2007-09-27 | df = }}
4. ^{{cite web | url = http://www.microsoft.com/windows/windowsmedia/licensing/final.aspx | title = Windows Media Licensing Royalties for Final Products | publisher = Microsoft }}
5. ^{{cite web | url = http://www.mpegla.com/avc/avcweb.ppt | format = PowerPoint | publisher = MPEG LA | title = AVC Patent Portfolio License Briefing | date = 2007-12-12 | deadurl = yes | archiveurl = https://web.archive.org/web/20070731204707/http://www.mpegla.com/avc/avcweb.ppt | archivedate = 2007-07-31 | df = }}
6. ^{{cite web | url = http://www.mpegla.com/main/programs/AVC/Pages/FAQ.aspx | title = AVC/H264 Licensing costs and terms from MPEG LA}}
7. ^{{cite web | url = http://www.itu.int/rec/T-REC-H.264-200305-S | title = H.264: Advanced video coding for generic audiovisual services |date=March 2003}}
8. ^{{cite web | url = http://iphome.hhi.de/suehring/tml/ | title = H.264/AVC Software Coordination}}
9. ^{{cite web | url = http://www.iee.org/OnComms/PN/multimediacomms/Alois%20Bock.pdf | title = Advanced Compression Technologies for High Definition | first = Matthew | last = Goldman |author2=Alois Bock | publisher = TANDBERG Television}}

External links

AVC/H264 Licensing costs and terms from MPEG LA

EEtimes comparison of video codecs

{{webarchive |url=http://webarchive.loc.gov/all/20140118160449/http://www.m4if.org/exhibitions/NAB2005/presentations/session3-cvandusen.pdf |title=NAB2005 presentation: codec comparison slides 13-14 |date=2014-01-18}}

Codec challenge comparison on Doom9 with professional VC1 encoder, PeP, and x264 for H264 => x264 win the first round

Microsoft employee discusses differences between VC-1 and H.264

Comparison at Doom9

5 : MPEG-4|Multimedia software comparisons|Open standards covered by patents|Video codecs|Video compression