Intel Quick Sync Video isIntel's brand for its dedicatedvideo encoding and decoding hardwarecore. Quick Sync was introduced with theSandy Bridge CPU microarchitecture on 9 January 2011 and has been found on thedie of Intel CPUs ever since.
The name "Quick Sync" refers to the use case of quicklytranscoding ("converting") a video from, for example, aDVD orBlu-ray Disc to a format appropriate to, for example, asmartphone, in situations where speed is more important than the best possible quality.
Unlike video encoding on a CPU or ageneral-purpose GPU, Quick Sync is a dedicated hardwarecore on the processordie. This allows for much more power-efficient video processing.[1][2]
Quick Sync Video is available on Core i3, Core i5, Core i7, and Core i9 and new Core Ultra processors starting with Sandy Bridge, and Celeron & Pentium processors starting with Haswell.[3][4]
Like most desktop hardware-accelerated encoders, Quick Sync has been praised for its speed.[5] The eighth annual MPEG-4 AVC/H.264 video codecs comparison showed that Quick Sync was comparable tox264 superfast preset in terms of speed, compression ratio and quality (SSIM);[6] tests were performed on an IntelCore i7-3770 (Ivy Bridge) processor. However, Quick Sync could not be configured to spend more time to achieve higher quality, whereas x264 improved significantly when allowed to use more time using the recommended settings.[6]
A 2012 evaluation byAnandTech showed that QuickSync on Intel's Ivy Bridge produced similar image quality compared to theNVENC encoder on Nvidia's GTX 680 while performing much better at resolutions lower than 1080p.[7]
Quick Sync was first unveiled at Intel Developer Forum 2010 (September 13) but, according toTom's Hardware, Quick Sync had been conceptualized five years before that.[1] The olderClarkdale microarchitecture had hardware video decoding support, but no hardware encoding support;[5] it was known asIntel Clear Video.
Quick Sync was initially built into someSandy Bridge CPUs, but not into Sandy Bridge Pentiums or Celerons. It addsH.264/AVC encoding andVC-1 decoding acceleration.[8]
TheHaswell microarchitecture implementation addsH.262/MPEG-2 Part 2 encoding acceleration.[1] An open-source hybrid driver was developed which supports partialVP8 encoding andVP9 decoding acceleration under Linux by utilizing both the integrated GPU and CPU[10][11], although as of 2023 Intel had explicitly abandoned both this driver[12] and pre-Kaby Lake accelerated VP8 encoding.[13] Starting from Haswell, Pentiums and Celerons have included QSV technology.[14]
TheBroadwell microarchitecture implementation adds VP8 hardware decoding.[15] Also, it has two independentbit stream decoder (BSD) rings to process video commands on GT3 GPUs; this allows one BSD ring to process decoding and the other BSD ring to process encoding at the same time.[16]
TheSkylake microarchitecture implementation adds a full fixed-functionH.265/HEVC 8-bit 4:2:0 decoding and encoding acceleration, hybrid and partial HEVC 10-bit decoding acceleration,JPEG encoding acceleration for resolutions up to 16,000×16,000 pixels, and partial VP9 decoding and encoding acceleration[17], although on Linux Intel has explicitly abandoned both the required "hybrid" driver[18] and Skylake accelerated VP9 decoding.[19]
TheKaby Lake,Coffee Lake,Whiskey Lake andComet Lake microarchitectures implementation adds full fixed-function H.265/HEVC 10-bit 4:2:0 decoding and encoding acceleration, and full fixed-function VP9 8-bit and 10-bit decoding acceleration and 8-bit encoding acceleration.[20][21]
TheIce Lake microarchitecture implementation adds VP9 8-bit and 10-bit decoding and encoding acceleration, H.265/HEVC 8-bit and 10-bit decoding and encoding acceleration with 4:2:2 and 4:4:4 chroma subsampling,[22] HDR10 Tone Mapping[23] and Open Source Media Shaders.[24] HEVC hardware encoding quality has also been improved.[25]
TheTiger Lake,Rocket Lake,Alder Lake &Raptor Lake microarchitectures implementation adds VP9 12-bit & 12-bit 4:4:4 hardware decoding and HEVC 12-bit 4:2:0, 4:2:2 and 4:4:4 hardware decoding.[26] Gen12 Xe will also support native AV1 decode, which includes 10-bit 4:2:0 16K stills and 10-bit 4:2:0 8K, 4K and 2K video.[27] Hardware encoding for VP8 was dropped and hardware decoding is only available on Tiger Lake.[22]
The Quick Sync VideoSIP core needs to be supported by thedevice driver. The device driver provides one or moreinterfaces, for exampleVDPAU,Video Acceleration API (VA-API) orDXVA for video decoding, andOpenMAX IL or VA API for video encoding. One of these interfaces is then used by end-user software, for exampleVLC media player orGStreamer, to access the Quick Sync Video hardware and make use of it.
Quick Sync support onLinux is available by both Intel VAAPI Driver (legacy, pre-Broadwell) and Intel Media Driver (Broadwell and newer) which also usesVA-API,[30][31] and through the Intel Media SDK.
Microsoft offers support for Quick Sync in Windows (inWindows Vista and later) based on supporting driver software from Intel and support through bothDirectX as well as WMF (Windows Media Foundation). A wide range of applications are based upon this base support for the technology in Windows.
Support for Quick Sync hardware accelerated decoding of H.264, MPEG-2, and VC-1 video is widely available. One common way to gain access to the technology on Microsoft Windows is by use of the freeffdshow filter. Some other free software likeVLC media player (since version 2.1.0 "Rincewind") supports Quick Sync as well. Many commercial applications also benefit from the technology today, including CyberLinkPowerDVD, CyberLink PowerDirector and MacroMotion Bogart "gold" edition.
According to theffdshow documentation, Quick Sync has very low CPU utilization while being about twice as fast aslibavcodec.[32]
The following table shows fixed-function encode/decode support for various Intel platforms.[41][42] Support for hybrid and/or partial decode/encode are not detailed.
Certain low-end and high-end parts (including multi-socketXeons and some Extreme Edition CPUs expected to be used with a dedicated GPU) do not contain the hardware core to support Quick Sync.
