gv-4097m hqx whitepaper

7/29/2019 GV-4097M HQX Whitepaper

1/12

White paper

Introducing HQXWhat are the main eatures o Grass Valleys Intermediate

Codec, and or what projects is it the best choice?

ak tkmoo, Dsko & ens Soluons

Dcmb 2010

t codc you coos o us wn you NLe s bcomng ncsngly ccl nd conusng s gow

n y nd numb o nu oms s xcdd only by o dlvy oms you clns sk o.in s , w dscuss wc wokows bs svd by so-clld inmd Codc. W go on o

dfn ky ccscs o inmd Codcs nd noduc hQX, wc s ls gnon n

Gss Vllys hQ mly o codcs.

inmd Codc soluons om svl vndos n comd n ms o cu quly, xbly,

nd subly o us w gcs s wll s vdo. W fnd n lk-o-lk ss, hQX os cu

quly coms vobly w o oul inmd Codcs. W lso sow hQX s suo

mul-gnonl omnc, wc wn combnd w nd soluon xbly nd bul-n l

cnnl suo, concluson inmd Codc s bs coc o cv ss skng

bs ossbl mg quly.

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Contents

Introduction 1

Intermediate Codecs 1

Wn o Us n inmd Codc 2

poul inmd Codcs 2

HQX Evolution 3

Superior Perormance o 10-bit Codecs 3

Com pcson 4

HQX Architecture and Profles 5

hQX Dsgn Ccscs 5

Codec Perormance and 10-bit Precision 6

pncl #1: all mgs conn nomon 6

pncl #2: rndom nos s ll noy 7

pncl #3: Lossy codcs nd o dscd noy s wll s ddng 7

Picture Quality Comparisons 8

Sngl Gnon pomnc 8

t conym pSNr snds o pk Sgnl o Nos ro 8

Mul-gnon pomnc 9

Conclusion HQX Maximizes Your Creativity 10


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1

IntroducIng HQX

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i sms numb o dn soucs nd oms

conn oducs v o us s nu ml mulls

vy dy. You my b bngng n raW 4k conn om reD

On, o ullng n hD om Gss Vlly LDK 3000. a

sm m, you gcs dmn s ovdng you w

ml om a ecs. t om xloson on nu

sd s mod by gowng vy o dlvy oms

you clns wll sk o, w mns vdo fls, od-

css, wbsms, o os o o oms.

as n do, vlu you bng o you cln s you cvy,

combnd w bly o m xcng cncl oducon

vlus w on-m dlvy. W nk you cvy s

mxmzd wn you NLe s sonsv, so xmn-

ng w cool cs nd comosons dosn mn w-

ng ound o nds; nd you cn u sd wos bou

w lys you buldng u comomsng

mg d. ts ll dds u o good s o sons o us

n inmd Codc, suc s hQX. So ls s w n

ovvw.

11920x1080 xls x 30000/1001 ms scond x (1 + + ) comonns x 10 bs comonn 8,000,000 bs mgby.

2a sngl Sata d dsk cn jus bou su ~180 MB/s yscl ly scfd by Sata 1.0.

t omnc o n NLe wokson s dmnd by

s mg ocssng ow nd ow quckly conn cn b

movd n nd ou o sog. You wokson slows down

onc lm s cd. Uncomssd hD conn 155

MB/s

1

wll mx ou bndwd o mos sog sysms

2

.So, w you o us uncomssd hD, CpU would snd

mos o s m dlng wl wng o sog o cc u.

O cous, son uncomssd vdo s cv, n

oy, s s bs mg quly ossbl. inmd

Codcs v bn dvlod o solv oblm o sog

bndwd wl mnnng cu quly s vsully dn-

cl w uncomssd ms. ty s ollowng

ccscs:

enoug comsson o lv sog bndwd s

bolnck comsson os nd o b n 5:1 o 8:1

ng. t mns sngl Sata 1.0 dv cn now suo

ou o mo cnnls bo mxng ou, vn llowng

o ovd o sng bndwd

No su-comlcd bcus CpU s sll ndd o

cs nd dng, no jus comsson

tnsn mg quly inmd Codcs lossy,

bu muc lss ggssv n cquson o lyou

codcs

ts cvs blncd us o woksons ky soucs

(CpU nd sog bndwd) wou mkng unccbl

comomss w cus.

a ycl wokow uss n inmd Codc s

sgs:

1) Bows, log, nd m souc m l, nd conv

om cquson om o inmd om

2) t dng ssson

3) rnd fnsd c o qud dlvy om(s)

Bo fs nd ls ss cn b m-consumng, so

nx scon xlos y o ojcs w usng n

inmd Codc s g coc.

Introduction

Intermediate Codecs


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2

IntroducIng HQX

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Whe use a Iemeiae ce

t coc o codc coms down o cos:

1) Us Sysm Codc. i my b ossbl o us sm codc ws usd o cquson. ts s gnun dvngs

o s-un wok, sclly bo nu nd dlvy ml uss n dvncd codc suc s aVC-in. howv,

cquson codc uss comomss suc s cu sclng, und-smld com, o only 8-b smlng, s no so dvsbl.and, o cous, mxu o oms w usd o nu m l, s oc sn ossbl.

2) Us Mxd Foms. You cn coos o us mxd oms s-s, nd s s g coc o s-un wok bcus you cn

g sd g wy. ts coc loss s llu o jobs mo c ond nd mul-lyd bcus o ssus

wll b ncound s mull gnons o nu ml gnd by dng ocss.

3) t o coc, nd on o wc s o s s dvod, s o us n inmd Codc, wc dlvs s

mon bnfs:

all wos bou mngng cu quly wl buldng comlx ds lmnd, nd s nbls you o ocus on

cv ocss, no cncl on.

an inmd Codc s bsoluly ss wy o g conn o you d dv nd ono you scn. ts mns

wng o cs o nd sn n ssu, nd by kng wng ou o wokng you cn sy n momn nd you

mos cv ougou n dng ssson.

eDiUS 6 om Gss Vlly llows you mk ny nd ll o s cocs so you cn mc you wokow o y o job nd.

Ppla Iemeiae ces

tbl 1 noducs mn inmd Codcs n common us ody nd summzs ky ccscs.

CnFom nd hQX s mon us o:

Us-dfnbl comsson os, lus

Bul-n l cnnl suo

Wll cov wy l cnnl suo s usul o on o ncssy l n s .

No bo DNxhD nd pors422 only o fxd b s, nd n ovds l suo n vdo colo sc.

rmmb uos o n inmd Codc s o mul uncomssd hD. Uncomssd hD s 10-b smlng,

wc s wy mos o s suo ls s, w DNxhD bng xcon. t monc o os wo bs s covd

l.

Now ls by vw voluon o hQX.

Intermediate Codecs (cont.)

Codec Compression Range Bit Rate (Mb/s) Bit Depth Chroma Alpha Support

HQX From 25:1 to 2:1 45 to 600 10 4:2:2 YCbCr Yes, 10-bit

DNxHD 8:1 or

5:1

145

220

8

8 or 10

4:2:2 YCbCr

4:2:2 YCbCr

No

No

ProRes 8:1 ProRes422

5:1 ProRes422 (HQ)7:1 ProRes444

147

220330

10

10Up to 12

4:2:2 YCbCr

4:2:2 YCbCr4:4:4 RGB

No

NoYes

CineForm From 10:1 to 3:1 120 to 400 Up to 12 4:2:2 YCbCr or

4:4:4 RGB or

RAW

No

Table 1 Summary of Intermediate Codecs.


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IntroducIng HQX

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HQX Evolution

Wn cu s dgzd, os noducd by ocss o unng connuously vbl sgnl no ss o numbs

v fn cson. Fo xml, sy you v l-wold sgnl cn ng bwn 0 nd 1V. W g bs o c-

son, youd ssgn mnmum cod vlu (zo) o sn boom o ng (0V), nd mxmum vlu (255) o -

sn o o ng (1V). W 10 bs o cson, you sn 1V w mxmum cod vlu vlbl w 10 bs,

wc s 1023. an 8-b cod cn sn 256 dsnc lvls n 0-1V ng, bu 10-b on cn sn 1024 dsnc lvls.

Look w ns wn you ncod l-wold sgnl 0.489844V n c sysm:

W n 8-b ng o 0-255, dl codng s 125.4, bu n 8-b cod s o ck ns wol numb o 125. ts

cuss n ovll o o -1.563 mV.

W 10-b cson n ng o 0-1023, ou cod vlu s 503, oundd down om dl vlu o 503.0753. t o

noducd s jus 73.6 V.

in s xml, qunzon o o 8-b cson s oxmly 21 ms lg n o 10-b cson, wc s

somw o n xm! On vg, 8-b cson noducs qunzon os ou ms lg n os o 10-b

smlng. ts conc s llusd gclly n Fgu 1 nd Fgu 2.

hQX s ls sg n voluon o hQ mly o codcs v bn ovdd s o eDiUS NLe.

tbl 2 glgs mn dvlomns n hQ mly o codcs snc 2004. i sows suo o sdly ncsng solu-

ons nd ovson o l suo s ou comonn s bn bul g no codc nd s bn u o

hQ mly snc 2006. as wv dscussd bov, s s on o os us dsnguss u inmd Codc om

os dsgnd mo o cquson o nsmsson.

in ddon o ncsd soluon, mon ugd ncludd w hQX s 10-b vdo. Ls k clos look w bn-

fs os x bs bng o you dng ssson.

Qunzon s omd by cu dvcs suc s cms o fld cods, wc ncsngly cbl o cung c-

us w 10-b cson. t qunzon os (o nos) noducd by cu dvc unvodbl, bu only n

onc. W dos s v o do w inmd Codc usd? t nsw s w o no scond, muc nos s o

os s noducd wn n 8-b inmd Codc s usd o comss 10-b sgnl.

Superior Perormance o 10-bit Codecs

Table 2 HQX evolution.

Figure 1 10-bit vs. 8-bit quantization. Figure 2 Comparison of quantization errors.

Features Released Resolution Chroma Bit Depth Alpha Support

HQ 2004, EDIUS 3 1440x1080 4:2:2 8 No

HQ with Alpha 2006, EDIUS 4 1920x1080 4:2:2 8 Yes

HQX with Alpha 2010, EDIUS 6 Up to 4k 4:2:2 10 Yes

Original

Analog

Signal

8 Bit

Quantization

10 Bit

QuantizationError due to 10-bit

Quantization

Error due to 8-bit

Quantization


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IntroducIng HQX

Qunzon dds nos o you cu wc s on nocbl s vsbl bndng o conoung, oug somms ocss

clld o duson s usd o d conous so y lss nocbl, bu ol moun o nos s sll sn.

Wll dscuss wy s s so mon consdng no bnf usng 10-b cson ovds: mo ccu colos.

chma Peisi

Bcus wo comonns usd o cod com nomon, 8-b vdo cn sn, mos, 50,000 dn com vlus

(cod vlus blow 16 nd bov 240 no lgl, so 224, no 256 dn vlus ossbl o Cb nd C).

10-b vdo cn sn 16 ms s mny: s ov 800,000 dn com vlus

On o mon bnfs o snng colo mo cculy s wn ullng ms om gn scns (o blu, o

d) you cn g muc fn olncs on colos n o ou o m, wc mks you comosons look mo

convncng.

Now ls look sucu o hQX codc, vw s cbls, nd s wy usng 10-b cson ls codc dlv

nsn cu quly qud o inmd Codcs.

Fgu 3 lluss sul o s ocss, nd Fgu 4 sows cu sd-by-sd w nos n jus boom wo bs o

c xl3.

Superior Perormance o 10-bit Codecs (cont.)

www.grassvalley.com

Figure 3 Noise added by 8-bit quantization of 10-bit signal.

Figure 4 A picture and the noise in its bottom two bits.

3No: a gn o 40 s bn ld o mk nos sly vsbl.


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hQX s n ccu s common o mos vdo codcs bu dos u us n cg o wo ky ms v dlog

box sown n Fgu 5. t M m fxs mxmum b- s con o uncomssd . So, M=10, co-

sonds o 10:1 comsson, M=20 cosonds o 5:1 nd so on.

t Q m govns ow ggssvly lgom comsss mg, w g vlus o Q cosondng o mo

ggssv comsson.

5

IntroducIng HQX

HQX Architecture and Profles

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Figure 5 HQX codec architecture.

Table 3 HQX design characteristics.

Block

Transform

Quantizer Entropy Encoder

Rate control Q is

increased as frame

size limit is

approached

M Parameter

determines maximum

size of compressed

frames

Q Parameter

determines quantizer

aggressiveness

Uncomssd mgs fs sl no smll blocks, c o wc s nsomd. tnk o nsom s quvln o

kng lg moun o wok, nd song no wll-dsgnd flng sysm. i dosn k ny cu nomon wy,

bu by ognzng b, dos duc noy o noml cus. O cous, o nos, cn do s.

t Qunz s w dcsons md bou w nomon cn b dscdd. i dos s n n nllgn wy svs mos sgnfcn nomon.

t noy ncod s losslss, mc cod, sml o lgoms lk WnZ. t dbck loo cuss qunz o

bcom mo ggssv mxmum m sz could b xcdd.

t svl dcsons w ny codc ccu dmn ovll fcncy nd omnc o codc, nd

ndlng ccscs o comssd ml. tbl 3 summzs cocs w md o hQX.

Parameter HQX Setting Beneft

Resolution Flexible, with support or up to 4k Work with your content in its native resolution, but without the timepenalties o using a resource hungry-acquisition codec.

Chroma Sampling 4:2:2 Matches the chroma sampling o HD-SDI so no chroma inormation is

lost by HQX.Sampling Precision 10 bits Lower noise, better compression, avoids banding or contours, fner con-

trol on chroma keys, apply gain or level shits to eight-bit contributionmaterial (e.g., XDCAM) without introducing undesirable artiacts.

Alpha Support Yes, 10-bit Graphics are simple to work with once theyve been encoded as HQXbecause access is ast, and high picture quality is maintained.

Bit Rate User defned as a raction o the sourcematerials bit rate. Typical values or HD are145, 220, and 400 MB/s

The user decides the amount o compression thats right or the job.High bit rates are available when near-uncompressed quality is desired.

Bit Rate Variation VBR, with strict maximum Better pictures or the same number o bits compared to CBR schemes.Strict maximum avoids network and storage glitches that can be causedby sudden spikes in bit-rate exhibited by some Intermediate Codecs.

Frame Structure Intra coding only Easier clip management and editing.

HQX desi chaaeisis


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IntroducIng HQX

aloug mny dn mg nd vdo codc lgoms vlbl ody, w suos glgng cnol-

ogy usd, w b cls, wvls, o DCts, y ll o on common s o bsc ncls.

Piiple #1: All imaes ai ifmai

how muc nomon dnds on cu.

Fo nsnc, colo bs v vy ll nomon bcus s lmos vl o dc vlu o c xl bsd on sngbos.

hgly dld mgs conn los o fn xu conn muc mo nomon, bcus s no ll vl o dc

vlu o ny gvn xl w ccucy.

inomon scnss us wod noy s msu o moun o nomon n mg conns. in lymns

ms unxcdnss s good wy o undsndng noy. tngs unlkly nd undcbl conn mo nom-

on (nd noy) n ngs f n obvous n.

an noml wy o msu noy o n mg s o comss w losslss lgom suc s WnZ.

Fgu 6 nd tbl 4 sow moun o noy n c cu xssd s bs xl. and su noug, sows

colo bs nd ycl l cnnl conn conn dly ny noy, bu noml cus v qu lo, nd nos s no-

ng bu noy.

Codec Perormance and 10-bit Precision

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Name Bars Alpha Goldhill Lena Baboon Noise

Picture Size (bytes) 1,049,760 307,200 414,720 262,144 65,536 250,000

WinZip File Size(bytes)

9,780 10,077 337,947 224,019 61,299 246,572

Estimated Entropyper Pixel (bits)

0.22 0.26 6.51 6.83 7.48 7.89

Table 4 Entropy content of various images.

Figure 6 Entropy content of various images.


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IntroducIng HQX

Piiple #2: ram ise is all epy

in ly ms, losslss codcs lk WnZ wok by sng

noy n fl om ddng (.., wo x null bs

nsd nd o n 8-b wod o bcom 10-b wod).

t noy s svd no comssd fl, nd d-

dng cn b dscdd. Wn d-comssd, ddng su bck o xcly consuc ognl d.

Wn sgnl s ndom nos, s ll noy, so s no

ddng o dscd. By wy, s wy you cn com-

ss fls v ldy bn comssdo xml

zng JpeG ly gns you ny dsk scbcus

noy o JpeG fl s bn mxmzd o bs bly

o JpeG lgom.

Piiple #3: Lssy es ee isa

epy as well as pai

a losslss codc s dong wll cvs comsson o

o 2:1 (.., comssd fl s l sz o uncom-

ssd on). t comsson os usd by inmd

Codcs g n s, w os o 5:1 nd 8:1 n com-

mon us. ts mns inmd Codc mus dscd

noy w ddng, wc mks lossy codc.

O cous, mo noy ognl mg conns,

mo o wll v o b dscdd dung ncodng

ocss.

ts s wy s nong o b gnd gno ng 20% o you

mg dbcus dong so dds noug qunzon nos

o counc ny soug-o bnf suc s b cu qul-

y o mo codng fcncy. t somw coun-nuv

sul s , o sm mg quly, codcs usng 10-b

cson cn cv sm b-s s codcs only

us 8-b cson on 10-b nu d. ts fndng s dmon-

sd n tbl 5, wc sows long-un cu quly

o codcs w 10-b cson (hQX nd pors422) s vy

clos o DNxhD, wc s n 8-b codc n 8:1 clss o

comsson ofls.

So, s x wo bs cvly com o , wy no

k dvng o bnfs?

Codec Perormance and 10-bit Precision (cont.)

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IntroducIng HQX

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t noml wy o mkng objcv comsons bwn

dn vdo codcs s v k sgnl-o-nos

o (pSNr) omnc o som wll-known nc

squncs. aloug pSNr dos no modl wy n

wc umn vsul sysm cvs nos cd by

mg comsson, s bo objcv nd sgowd o

comu (s sdb). Dncs bwn codcs onlysgnfcn dnc n pSNr xcds oxmly

2 dB. is mon sm nc conn s usd

wn comng codcs bcus codc omnc s unc-

on o uncomssd mg.

t euon Bodcsng Unon mks vlbl s o

uncomssd nc squncs commonly usd

o vlu codc omnc.

t eBU squncs, comsng 1250 ms o vdo, w

usd o vlu wo ky omnc msus o numb

o inmd Codcs.

Sile geeai Pefmae

t fs omnc mc s o clcul sgnfcnc

o os noducd by sngl ncod/dcod

gnon o c codc.

Wv lod pSNr o c m n squnc o

inmd Codcs n s clsss o ncsng com-

sson o: 3:1, 5:1, nd 8:1. rmmb bgg numbs

b ln o o g sows codc w

bs cu quly on m-by-m bss.

to ovd long-un quly msu, vg pSNr o

c codc ov ll 1250 ms s lso bn comud. t

suls snd n tbl 5.

Picture Quality Comparisons

the aym PSnr sas f Peak Sial

nise rai

Its a handy, single-fgure measurement o how dierenta picture thats been through a codec is compared to the

uncompressed original.

Its calculation requires a ew simple steps:

1) Compress and decompress a reerence picture toproduce a resultant picture.

2) Subtract the resultant rom the original; the non-zero values in the resultant are errors that wereintroduced by the codec.

3) Square all the resultant pixels and add themtogether, then divide by the total number o pixelsto get a fgure or the Mean Square Error.

4) Form the Ratio by dividing the Mean Square Errorinto the Peak value a pixel can represent (SMPTE292 defnes peak white as code value 940, butprovides headroom up to 1019).

5) Express the ratio in dB.

MSE=1

N M

M

i=1

N

j=1

(refi,j resi,j)2

PSNR = 10 log10

Peak2

MSE

Figure 7 PSNR comparison of 5:1 class codecs, and HQX at 3:1.

Fgu 7 sns pSNr suls o ou s squnc o 1250 nc mgs. t c w bs pSNr s hQX 400

Mb/s w Q m s o zo nd M m s o 35. as you cn s, s muc b n o codcs

n s l bcus b s sgnfcnly g n os.

t cs o 5:1 clss sow hQX 220 Mb/s s combl o o inmd Codcs, nd nocbly b

n D5.

i w duc vg b , w ncoun clss o codcs usng n 8:1 o. t pSNr suls o wc sown n

Fgu 8.


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IntroducIng HQX

Picture Quality Comparisons (cont.)

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30

35

40

45

0 200 400 600 800 1000 1200

PSN

R

(dB)

Frame Number

HQX 145 ProRes422 DNxHD145 AVC-Intra 100

Figure 8 PSNR comparison of 8:1 class codecs.

Figure 9 Multi-generation performance of intermediate codecs.

h w s hQX s bs codc o som squncs, nd lwys vy clos o pors422 nd DNxhD codcs n s

comsson clss.

t long-un omnc o c codc s summzd n tbl 5. i sows hQX ovds combl quly o DNxhD nd

pors422 ov long un, combl b s. i lso sows hQX llows you o un quly dl ll wy u

sould you ojc m .

Fgu 9 sows hQX dos bs job o mnnng cu quly ov mull gnons, nd DNxhD nd

pors422 los cu quly qucklyvn ov fs wo o gnons.

Mli-eeai Pefmae

t scond ky omnc mc o inmd Codcs, n cul, s ow y bv wn cu s comssd

nd dcomssd svl ms. i you buld u you ds n lys, n s lkly you cng mull gnons o

ognl nu ml, nd s cuss comsson os o ccumul coss gnons. t omnc dncs

bwn inmd Codcs mo mkd s llusd n Fgu 9.

8:1 Class 5:1 Class 3:1 Class

Codec Mean bit rate Mean PSNR Mean bit rate Mean PSNR Mean bit rate Mean PSNR

HQX 145 38.9 dB 224 41.8 dB 400 46.4

DNxHD 145 38.6 dB 220 41.4 dB

ProRes422 147 39.1 dB 220 42.7 dB

AVC-Intra 100 37.4 dB

HD-D5 220 41.0 dB

Table 5 Summary of picture quality comparisons.


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IntroducIng HQX

SALES

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SuPPort

Local and regional support contacts can be ound by visiting

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Copyright 2010 Technicolor USA, Inc. dba Grass Valley. All rights reserved. EDIUS is a registered trademark and Grass Valley is trademark o TechnicolorUSA, Inc. All other tradenames reerenced are service marks, trademarks, or registered trademarks o their respective companies. Specifcations subject

to change without notice. GV-4097M

W v sown s mon o b

bl o mc codc you us o

wok you do. Fo s-un oons,

sysm codc, o usng mxd oms

s obbly bs coc; bu wn

mg quly nd cvy -

moun, n inmd Codc sould

b slcd bcus wll dlv s

mon bnfs:

inu soucs ndld

nsnly nd conssnly, vn

os ncludng l cnnls suc s

gcs

tcncl concns ov cu quly

sd om cv

ocss

an nmd codc s ss

wy o g g-lookng ml

bwn dsk nd scn

in ms o cu quly, hQX os

xclln omnc wn com-

d lk-o-lk w o mjo

inmd Codcs vlbl

om NLe mnucus, ncludng

pors422, nd DNxhD.

hQX os suo omnc n

ky s wn comd o o

inmd Codcs:

By ovdng dc suo o l

cnnls, s s nd sy o wok

w gcs wl mnng n

vdo colo sc

By mnmzng dgdon cusd

by mull gnons o ncodng

nd dcodng, cu quly o

you fnsd oduc wll b b

n mos o oul inmd

Codcs

By ung you, us, n cg o

b- nd qunzon oc

usd, hQX llows you o o you

clns cu quly s cl 10

dB b n you comos

So, wn cd w comlx sso-

mn o nu soucs, dmndng

cv b, nd g ddln,

sd nd nsncy bnfs o

inmd Codcs n gnl, u

og w hQXs suo o-

mnc n cul, om combnon

dds u o ncsd cvy o

you, nd ncsd vlu o you cln.

Conclusion HQX Maximizes Your Creativity

gv-4097m hqx whitepaper

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