Consumer Experience

Transcript

Consumer Experience Steven A. Silva FOX NE&O THAT’S WHY WE ARE HERE! Pre- DTV! Beautiful DTV! DTV System = Unlimited Choices         Analogue broadcasts ended on June 12, 2009 Unlimited choices began! DTV has transformed our TV viewing experience Enabled broadcasters to offer HDTV with surround sound Programming choices via multicasting & interactive capabilities i.e. 11.1, 11.2, 5.1, 5.2 & 5.3 VOD, etc Music channels DTV System = Unlimited Choices        We still have the 19.3 Mb/s broadcast pipe! (6Mhz) What about bigger channels i.e. > 6Mhz? 4K, 8K, 1080p60….need bigger channels! DTV by compressing the video & audio Video compression via MPEG 2 & 4, JPEG2000, etc. Audio compression via Dolby AC-3 Video & audio are combined in an HD-SDI multiplexer DTV System Pre DTV-Analog Mono TV DTV Surround Sound! DTV AC-3 System          Surround sound at the advent of HDTV Not intended to mimic the audio processing of analog TV Ability to provide consistent loudness between programs Allows listeners to select different Dynamic Ranges (DR) AC-3 system has the capability for 6 channels (5.1) Left, right, center, LFE (the .1 channel) , Ls and Rs Low frequency enhancement (LFE) for 20 to 120 Hz 48 KHZ sampling rate and up to 128kbps per channel I.E. Fox's bit rate for surround sound is 448kbps 5.1 Markets       FOX Broadcasting & FOX Cable that originates from L.A. is in 5.1 31 HDTV (720p) channels with surround 9 SD channels with 2.0 FOX Houston broadcasts 31 channels in HDTV (720p) FOX, NBC, ABC/ESPN, Turner and CBS all broadcast in HDTV with 5.1 Smaller markets down mix the surround to 2.0 Real time downmix  Instead of manually performing a down mix, a real time down mixer box can be employed  The downmixer automatically processes the signal to certain guidelines  Stereo  Lt/Rt  Low frequency enhancement is not used  The Dolby AC-3 stream has metadata values for the down mix It’s all about Metadata Management!  Metadata provides information, control and flexibility for the AC-3 stream  AC-3 allows up to 28 metadata parameters classified into 3 groups:  Informational metadata- 7 optional parameters which describe encoded audio  Basic control metadata- 19 parameters which determine dynamic range, compression, downmixing, matrix decoding & filtering  Critical control metadata- 2 parameters critical for proper encoding and decoding.  Channel mode: proper channel formatting for decoder (i.e. 1-6 channels)  Dialog level: dialnorm i.e. -24  Default values mostly used for other metadata parameters Dynamic Range Management      AC-3 is not intended to mimic analog TV’s limited dynamic range! AC-3 eliminates or minimizes traditional compression/limiting AC-3 is capable of delivering a Very Wide Dynamic Range (100dB) Provides producers with greater freedom to convey their artistic intent Allows listeners to have DR choices, with exceptions Dynamic Range Control  DRC modifies by reducing very loud portions and raising very low levels with reference to the dialnorm  Works via gain words in the AC-3 encoder which provide a “reversible” approach during decoding, allowing users to select a desirable dynamic range within their equipment and viewing environment  But can only be effective with an accurate dialnorm!  Home system users can use DRC on or in the off mode for the full dynamic range  Line mode- slightly reduces DR for directly connected audio components  RF mode- for more aggressive use with RF legacy loudness matching AC-3 DRC AC-3 DRC         AC-3 encoder calculates gain words for selected DR profiles Choice of the compression profile is up to the program producer 5 profiles: Music light, Music standard, Film light, Film standard & Speech “None” choice, inhibits the generation of DRC control words & DRC functionality None choice can be problematic due to being irreversible! Decoders have 2 required main “modes”, line and RF Listener has options from the AC-3 stream Loudness normalization is always applied AC-3 DRC DRC profiles Too LOUD!! Loudness Management      Loudness- That’s how we hear! Manage quality and hopefully, not a lot of complaints! Prevention is the key! Loudness specifications via broadcasters KEY: CONSISTENT & SIMPLISTIC measurements Loudness Terms       Dialogue, that’s what it’s all about or is it? Mixed content i.e. Fox series “Terra Nova” Target Loudness i.e. -24LKFS, in the specifications & goal of the mix Technical audio specifications should always state the Target loudness Anchor element, content mixed around, via target for overall loudness Dialnorm, average loudness of mix & that value placed in encoder Fox’s Consumer Challenges            Began 9 yrs ago with issues concerning loud commercials in FB games HDTV kickoff in 2004 What location do we make the measurements? Internal/External Large quantity of LM 100’s available Automated our LM100’s Leq A What is the anchor point? Dialogue centric? Do we measure just the center channel? Other combos? What about DR issues? What about silent periods? D/I challenges. What other meters have DI? Fox’s Consumer Challenges      LKFS has become the standard with gating Leq A’s plots closely mirror LKS & are generally ½ to 1½ dB greater Fox measure’s 5.0 Measure programs and interstitials as segments DI off for uniformity Thank You DTV Education       Broadcast realm It’s FREE! ATSC RP A/85 SVG’s DTV Audio Group via SVG Loudness online tutorial, released in 2011 In production on a “Surround Mixing” on line tutorial, which will be released earlier next year  3 E’s, Educate, evaluate, and enforce! Thank You