- Comparison of H.264 and VC-1
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H.264 and VC-1 are popular video compression standards gaining use in the industry as of 2007[update].
Contents
Overview
VC-1 H.264 Goals Designed to offer very high image quality with excellent compression efficiency[1] Designed to meet a variety of industry needs with many profiles and levels, allowing for varying compression, quality and CPU usage levels, where the lowest level is for portable devices, designed with low CPU usage in mind, while the high levels are designed with very high quality and compression efficiency in mind[citation needed] 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 modeLicensing 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 16x16 and 8x8[9] 16x16, 16x8, 8x16, 8x8, 8x4, 4x8, and 4x4 Integer transform 8x8, 4x8, 8x4, and 4x4 4x4; 8x8 available in High Profile only Frame Used for progressive or interlaced content Macroblock sizes 16x16 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, macroblockDeblocking filter In-loop filter and overlap transform In-loop only CABAC No 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
- ^ Loomis, Jay; Mike Wasson. "VC-1 Technical Overview". Microsoft. http://www.microsoft.com/windows/windowsmedia/howto/articles/vc1techoverview.aspx#Conclusion.
- ^ SMPTE Technology Committee C24 on Video Compression Technology (2005-08-23). SMPTE421M: SMPTE Draft Standard for Television.
- ^ "VC-1 Patent Portfolio License Briefing" (PowerPoint). MPEG LA. 2007-11-05. http://www.mpegla.com/vc1/vc1web.ppt.
- ^ "Windows Media Licensing Royalties for Final Products". Microsoft. http://www.microsoft.com/windows/windowsmedia/licensing/final.aspx.
- ^ "AVC Patent Portfolio License Briefing" (PowerPoint). MPEG LA. 2007-12-12. http://www.mpegla.com/avc/avcweb.ppt.
- ^ "AVC/H264 Licensing costs and terms from MPEG LA". http://www.mpegla.com/main/programs/AVC/Pages/FAQ.aspx.
- ^ "H.264: Advanced video coding for generic audiovisual services". March 2003. http://www.itu.int/rec/T-REC-H.264-200305-S.
- ^ "H.264/AVC Software Coordination". http://iphome.hhi.de/suehring/tml/.
- ^ Goldman, Matthew; Alois Bock. "Advanced Compression Technologies for High Definition". TANDBERG Television. http://www.iee.org/OnComms/PN/multimediacomms/Alois%20Bock.pdf.
External links
- AVC/H264 Licensing costs and terms from MPEG LA
- EEtimes comparison of video codecs [1]
- NAB2005 presentation: codec comparison slides 13-14
- 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
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