Post on 18-Dec-2015
Cerify – File Based Quality Control
Yannick LE DREAU
Tuesday 18 April 2023
Outline
The Business Case
Cerify Workflows and Applications
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The Business Case
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Business types
Segmentation
– Business areas– Content Services– Traditional Broadcasters– Advertiser Services– VoD & IPTV– Post Production Houses
– Applications– Ingest– Repurposing– Delivery
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Business area examples
Segments include– Content Services
– Ingest once, re-purpose many– iTunes encoding and delivery– archive/asset management at high bitrate encoded video
– Traditional Broadcasters– Ingest once, re-purpose many– Ingest and playout of high bitrate encoded video
– Advertiser Services– Advertisement/commercial encoding and delivery
– VoD & IPTV– Encoding for web, VoD, mobile
– MPEG 2 Transport streams– 3GPP files– Windows Media
– Post Production Houses Content services– File based workflow and delivery to broadcaster
– Mainly commercials
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Typical Applications of different “SD” codecs
Video Codec Typical applications (new)
MPEG-2 Broadcast, cable, VOD, DVD
H.264 / AVC / MPEG-4 Pt 10
Broadcast, cable, VOD, HD, Internet, HD video disks*
WM9/VC-1 Broadcast, HD, Internet TV, HD video discs – Blu-Ray
DV/DVC-Pro 25/50 Broadcast, Acquisition, Editing
MPEG-4 Pt 2 Mobile
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Typical Applications of different “HD” codecs
Video Codec Typical applications (new)
DNxHD/VC-3 Editing, Broadcast Playout
AVC-Intra Acquisition, Editing
Pro-Res Editing, iTunes
JPEG 2000 D-Cinema, broadcast internal use/archive
DVC-Pro100 Acquisition, Editing, Broadcast Playout
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MPEG-2: Typical Configurations
SDTV, DVD– MP@ML, 720 × 576, 4:2:0 colour format, 25 fps
HDTV– MP@HL, 1920 × 1080i or 1280 × 720p, 4:2:0 colour format, 25 fps
Ingest SD (Sony IMX MPEG 2 I-Frame Only)
422P@ML, 720 × 608, 4:2:2 colour format, 25 fps
Ingest HD (Sony XD-Cam MPEG 2 long GOP)– 422P@HL, 1920x1080 4:2:2 colour format, 25fps
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AVC/H.264/MPEG4 part 10
Is an “open standard”, compared to closed formats, like Microsoft's Windows Media
Performs significantly better than any prior standard can, under a wide variety of circumstances in a wide variety of application environments
H.264 can often perform radically better than MPEG-2 video—typically obtaining the same quality at half of the bit rate or less
Can be carried by MPEG-2 Transport Streams making it increasingly used in HD VoD applications.
AVC-Intra is a Panasonic P2 implementation of Intra frame coded AVC. Gaining popularity for acquisition and editing.
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DNxHD/VC-3 Avid’s DNxHD is a HD codec technology engineered to create
mastering-quality HD media at reduced bit rates to allow HD editing and production using SD infrastructure.
In January 08 it was approved to be compliant with SMPTE 2019 VC-3
There is support from EVS and Omneon amongst others for playout.
Image © Avid.com
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DNxHD Key benefits
– Optimal mastering picture quality
– Reduced storage requirements – Enables real-time HD sharing and collaboration – Improved multi-stream performance
– Specifically engineered for multi-generation compositing and post production
– Full frame raster sampling
– Choice of 8- or 10-bit sampling as well as three user-selectable bit rates
– Open standard: HD Codec source code is licensable free of charge
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Apple Pro Res 422
Unlike DNxHD, ProRes 422 provides full functionality at advanced resolutions (2K and 4K cinema) and SD.
It is DCT based, and is therefore simpler to decode than distribution oriented formats like H.264.
Full-width 1920x1080 and 1280x720
4:2:2 chroma sampling
8 and 10-bit sample depth
I frame-only encoding
Variable bit-rate (VBR) encoding
Normal 145 Mbit/s and High-Quality 220 Mbit/s for HD resolution
Normal 42 Mbit/s and High-Quality 63 Mbit/s for SD resolution
Fast encoding and decoding (both at full size and half size)
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MXF – Wrapper
Media eXchange Format
Developed as a global wrapper format for all video, audio and metadata
Specification is layered. “OP1A” configuration is most commonly used today (simplest implementation of MXF)
File interchange for networked AV file distribution
Format independent– Picture Size – Interlaced or Progressive– Audio Sampling Rates
Wraps all formats– Current and future formats– Metadata only files allowed – Compressed and uncompressed
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Broadcast Operational challenges
Ingest and Playout are in transition– Analogue to Compressed Digital
Methods of storing video are changing– Tape to File based stored on video Servers
Many different new formats– Terrestrial, Satellite, Cable, VoD, IPTV– Sub SD, SD, HD,– MPEG-2, MPEG-4, H.264/AVC, VC-1 etc
Content is being re-purposed at different resolutions and frame rates, using new codecs and at different bit-rates, with different technical requirements
Explosion of content from many sources for different channels and in different formats
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The file based QC challenge
15
VisibleErrors
InvisibleErrors
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Broadcasting Human Quality Control Challenges
Human QC/play-out testing is time consuming and expensive
Visual/audio errors are easily missed with human play-out– just by blinking or losing concentration for a second– different skill level/experience/training of testers
Simple errors – human may not get constraints correct
Consistency – cannot repeat exactly the same test on content, day after day, week after week
Person cannot easily look inside the file for example:– correctness of encoding used for compression for video, audio– bit-rates of video, audio and overall– syntax errors in the file which may prevent it playing correctly– correct playtime of the video and audio– audio on correct channels– visual quality ...
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File Based video Quality Control
File Based Video QC Application Challenges– Traditional video T&M only checks baseband (luma/chroma/signal) levels
in analog and digital video streams– File-based video is different. It must be checked for
– Correct Encoding Syntax – at digital level, audio/video must be encoded without errors, so it plays out correctly at the Customer’s STB / playout device
– Correct Parameters – audio/video bitrates, GOP structure, Color-space, Color depth, Frame size, Frame rate, Aspect ratio, Quantization levels
– Correct Baseband and Quality levels - analog parameters for Signal levels, Luma, Chroma, Gamut and Quality levels of Black frames, Blockiness, Loss of audio, Audio clipping, Video/Audio playtime
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Video Quality Control Video QC is a delivery requirement by many
broadcasters. QC Operators would be looking at:
– Black and white level– RGB Gamut and possibly composite gamut– Number of audio channels, level and loudness
peaks, phase– Picture action and graphic safe areas in all
deliverable aspect ratios– Creative quality and attached metadata such as
program duration, commercial breaks and clock details
– Video blanking– Timecode presence and continuity– General picture quality, standards conversion and
compression artefacts, tape drop out
Some of the above can be automated
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Why Automate Quality Control?
We can automate our classic QC tools such as WFM and WVR– What do our customers do today?
– They use logging– They use SNMP traps
Broadcasters are moving to a Service Orientated Workflow– Using more file based technology
– File base acquisition– Panasonic P2 Cards– Sony XDCam SxS cards
– File based editing– Apple Final Cut Pro– Avid Media Composer
– File based archive– Isilon– Omneon MediaGrid
– File based Playout– Omneon Spectrum– Grass Valley K2
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Why Automate Quality Control
Save time– Non-linear workflow
– QC can happen at the same time as proxy creation/transcoding
Save resources– Skilled Quality Control operators are few and expensive– Automated QC is a tool for the department
Give Consistency– Repeatable results
QC Operators looking at a broadcast monitor cannot easily “look inside” the file
– Are the correct parameters of encoding used for compression for video, audio?
– Are the bit-rates of video, audio and overall correct?– Syntax errors in the encoding may prevent it playing correctly further on
in the workflow– Is the metadata correct?
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Content VerificationService Level Agreement (SLA) Audit Points
Cable
Cerify File based Audit point
PostEncode/Reformat
Ingest Edit /Transcode
PlayoutLibrary
Content On Demand On Line Service Provider
Ingest Edit /Transcode Playout
Broadcaster
Archive
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What does Cerify test?
Systems level tests– Correct Standard and integrity– File size, Bitrate, Playtime, Number of video/audio streams, CableLabs VOD
compliance, – Video and audio PIDs, Signalling of Closed captions– Playtime of video vs playtime of audio
Video Tests– Correct encoding Standard, Profile, Level and Syntax checks for encoding errors – GOP structure, Frame rate, Bitrate, Frame size, Interlaced/ progressive, Aspect
ratio– Baseband tests including Gamut levels, Luma, Chroma, Signal levels– Letterbox/ Pillarbox, Playtime– Freeze frame– Color depth, Color format (4:2:0, 4:2:2), Copyright– Field order, Telecine pulldown– Quality - Black frames (lead in, lead out and during the video), blockiness,
Quantization
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What does Cerify test? - cont
Audio Tests– Correct encoding Standard, Profile, and Syntax checks for encoder errors– Sample rate, Bitrate, Playtime– Number of Channels, Peak and Minimum Signal levels on each channel – Audio Silence (lead in, lead out, during video), clipping, mute, test tones
Reporting– Web based on-screen job reports and detailed drill down to error details– Copy or move file on success or error – Email alerts with test reports – CeriTalk API for fully automated working and integration with Automation /
Asset Management systems
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Benefits of Automated QC
Quality Control Strategy– Saves time and money over human playout testing– Works 24/7– Enables all of your file-based content to be checked all of the time
Provides a Content Filter to catch errors that people can easily miss, and perform repeatable objective testing
– Performs automatic, consistent and thorough checks of content files against user-defined templates
– Allows QC staff to concentrate on 5% of rejected files not watching the 95% of good files
Ingest / Transcode / Archiving– Check encoded content at ingest to resolve problems early – prevent problems from
entering your workflow– Monitor your Service Level Agreements and the quality of your supplier’s content– Check before and after transcode, edit and archiving
Playout– Check your files are ready to playout– Improves broadcast QoS by minimizing risk of transmission and reception defects
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Cerify Workflows and Applications
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Identifying the workflow
There are 3 main types of workflow available with Cerify– Manual job creation and results viewing
– Semi-automatic using Watchfolder/dropbox– Manual viewing of results in web GUI– Automatic email reports generated and sent– Automatic XML reports generated and saved on network– Custom Action Scripts
– CeriTalk API– Uses SOAP– Large list of members of the Cerify Developer Community – new Partners
added monthly– Best way to control Cerify– May require development effort from Automation/Asset Management Partner
Workflow chosen depends on application/size of facility
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Cerify Workflow – Network Setup
BROWSE STATIONS FILE SERVER
CERIFY CYC200
Gigabit Network
Gigabit Network
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Manual Workflow – monitoring results
Files are added to MediaSets manually
Jobs are created manually
Results are reviewed by an operator
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“See and Solve” Test Results Details of Cerify results are
displayed on the user GUI in levels
The amount of detail increases as you “drill down” to lower levels
Details of a specific error alert
Video thumbnails and audio waveform shown in frames surrounding the alert
Details for each file within the “Job”
Alerts for each error within the file
Test summary for each file in “Job”
Alert traffic lights
Thumbnail of erroneous frame
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Semi-Automatic Workflow – Cerify Email Reports
Files are added to MediaSets automatically using “watch folders” or “drop boxes”
Jobs are created manually using these mediasets
Results are sent by email and reviewed by an operator
The operator can “click through” from the email to the Cerify web GUI for thumbnail viewing
Tuesday 18 April 2023
Semi-Automatic Workflow – Cerify XML Reports
Files are added to MediaSets automatically using “watch folders” or “drop boxes”
Jobs are created manually using these mediasets
Results are stored on a server in XML
They can be reviewed by an operator or picked up by an asset management system
The operator can “click through” from the XML to the Cerify web GUI for thumbnail viewing or an asset management system can use these URLs to gather the thumbnails
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Automated Workflow – using the CeriTalk API
Tektronix has a Partner program to aid Cerify Integration– This is the Cerify Developer Community or CDC
3rd Party Applications (typically Asset Management) control Cerify– File is ingested– Job is created on Cerify by automation system– Results are fed back to automation system
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Cerify Developer Community - CDC
Note: The community is growing rapidly. Please check with Tektronix for latest list or visit http://www.tek.com/products/video_test/cerify/cdc.html
Working together for integrated solutions with Cerify automated QC
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Case Study - VoD
Overview– The customer encodes a master file in HD– SD and HD low bitrate versions are made from the master file– The master file is archived for later re-use
Workflow– High resolution/high bitrate master file ingested manually– Encoded file is moved to a high bitrate watch folder– Transcoder picks up the master file and creates 2 low bitrate versions– Auto Quality Check tests the files in these watch folders for encoding
syntax, parameters and various baseband values and sends emails on error to alert QC Operator
– Dolby DP600 used for Dolby AC-3 encoding, correction of audio metadata and levels
Cost benefits of auto QC– As volume of media goes up costs can remain low– The complete file is tested not just 3 or 5 point spot check
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Workflow Example - VoD
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Case Study – Broadcast Playout Centre
Overview– Tape and file ingest controlled by Media Asset Management and automation
system– Important decisions on the format taken e.g. AVC-Intra, IMX, MXF, XDCam– Can be complex and highly automated– Uses Cerify’s web services SOAP API– Low number of transcode/un-wrap/re-wrap steps
Workflow– Asset Management requests media to be ingested– After ingest job is created on Cerify for testing– Cerify is polled for the results/progress– Results are provided on completion as XML over SOAP– Results are displayed in GUI
Cost benefits of auto QC– Clear penalties for playout centre failing to schedule a show or commercial –
Service Level Agreements– Quality of the channel brand upheld
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Workflow Example - Broadcast Playout Centre
Tuesday 18 April 2023
How fast is Cerify?
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Cerify Benchmarks
Cerify Lite is difficult to bench mark because the hardware is customer supplied – it will process one file at a time
– Typically on a 3GHz processor with 2Gb RAM– 50Mb/s SD MPEG2 is realtime– 12Mb/s SD MPEG2 is 0.5 x realtime– 8MB/s SD H.264 is 2x realtime
CYC200 & CYM200 will process 4 files at the same time– 50Mb/s SD MPEG2 is realtime– 12Mb/s SD MPEG2 is 0.5 x realtime– 8MB/s SD H.264 is 2x realtime
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Cerify Processing
To define the speed– Firstly the codec
– MPEG2 is faster than H.264– The syntax testing takes the most time
– Secondly the bitrate and complexity– I frame only is simpler than long GOP– Low bitrate is quicker than high
– Thirdly the resolution– HD takes longer to process than SD
– Fourthly – the baseband tests– Colour Gamut and luminance tests take more processing power than black
frame detection
The most important test is the syntax– This takes most of the processing
Limit the number of tests switched on– Limit the baseband tests to those most appropriate
Tuesday 18 April 2023
Questions?