dave maccarn wgbh thomas edwards pbs carl fleischhauer library of congress an overview of mxf and...

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

An Overview of MXF and the Search for the Video

File Wrapper.

NDIIPPPreserving Digital Public

Television

JTS 2007Toronto

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

Universal Preservation Format

• Self describing storage– Must know the coding of the file.– Must know the coding of the essence

within the file.

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

Universal Preservation Format

• Wrapper contains both essence and metadata– Must know the location of the essence

and metadata within the file.

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

Open Source Codecs

• Report on File Formats and Packages– http://www.ptvdigitalarchive.org

• VLAN– http://www.videolan.org/

• FFMPEG– http://ffmpeg.sourceforge.net/index.php

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

Source Code Links

• http://www.free-codecs.com/• http://www.avsmedia.com/downloads/

codecs.aspx• http://forum.doom9.org/• http://sourceforge.net/projects/libdv/• http://www.openquicktime.org/

– http://www.free-codecs.com/download/QuickTime_Alternative.htm

• http://dirac.sourceforge.net/• http://www.avid.com/forms/DNxHDinfo.asp

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

MXF Background & MXF - AS/PBS

Thomas EdwardsPBS

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

MXF – What is It?

• Material eXchange Format• Influenced by the “EBU/SMPTE Joint

Task Force for Harmonised Standards for the Exchange of Television Programmes as bit streams”

• A “wrapper format” that ties together essence and metadata elements into a coherent whole

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

What can you do with MXF?

• Store simple completed works with metadata

• Store files in a streamable format• Wrap up a playlist/EDL and essence

with synchronization information• Wrap a wide variety of compression

formats

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

KLV Coding (SMPTE 336M)

– K= Key: a unique identifier– L= Length: how long is the field

Encoded with ASN.1 BER, so can be as big as needed

– < 0x80 is actual length (0-127 decimal)– 0x8Y implies next Y bytes contain actual length– Example: 0x82.10.00, length is 0x1000 = 4096

decimal

– V= Value: what is the value of the field

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

KLV Using SMPTE MDD

06.0E.2B.34.01.01.01.02.01.05.08.00.00.00.00.00

SMPTE Designator SMPTE Item

14 47 6F 6E 65 20 57 …

Length

“Colonial House”(in ISO-7 bit code)

Value

“Version Title”

UL – SMPTE Universal Label

(16 bytes)

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

Simple Versus Complex

• MXF files can be very simple– “Just wrap up my essence”– E-VTRs, Video Servers

• MXF files can be very complex– EDL’s, alternate packages– Self-referential clips– Software implementations

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

Simple MXF File

• Partitions– Logical division of a file for easier parsing

• Header– Has metadata about whole file

• Body– Contains essence

• Footer– Terminates file & can have updated metadata

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

Metadata in MXF• Structural Metadata

– Capability of a file & how it is constructed

• Descriptive Metadata– Editorial aspects of the file– Several “schemes” available, such as DMS-1

• Dark Metadata– Metadata unknown by some applications

• Static Metadata– Doesn’t change over entire output– e.g. Show title, producer, etc.

• Time-Dependent Metadata– Timeline or Event– e.g. “This part was shot by Bob”

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

MXF Object Model

• Packages– A logical grouping of metadata sets

• Material Package– Represents output timeline– Owns Tracks

• File Package– Represents actual essence in the file

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

Physical vs Logicalphysical - how the bytes are stored (essence container)

logical - what the bytes are intended to represent (packages)

PartitionPack

SoundElementK L fil

lK L

Hdr.

set

PictureElementK L

Hdr.

set

K L

Hdr.

set

K L

Hdr.

set

K L K L K L

Stored Picture Track

Stored Sound TrackFile Package

“played” PictureTrack“played” SoundTrack

Material Package

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

MXF Object Model cont.

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

“Frame Wrapped”

“Clip Wrapped”

KLV Wrapping of Essence

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

MXF Standards• SMPTE 377M MXF File Format

Specification • Essence Containers:

– SMPTE 385M SDTI-CP – SMPTE 381M MPEG (including long-GOP) – SMPTE 382M AES3 and Broadcast Wave Audio – SMPTE 383M DV 25/50 – SMPTE 386M D-10 (IMX 50 Mbps I-frame

MPEG2) – SMPTE 387M D-11 (HDCAM)

• Descriptive Metadata – SMPTE 380M MXF Descriptive Metadata

Scheme - 1 (DMS-1)

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

Why Bother?

• MXF is a good way to wrap up video essence into files

• MXF is a good way to link rich metadata to video essence

• MXF has support from many vendors for interoperation (but this is a work-in-progress)

• MXF and file transfer may provide significant benefits for an IT-oriented workflow

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

PBS File Delivery Project(NGIS)

• Distribute long-form, broadcast-quality video as files

• To 180 independent public television organizations

• Five major video server vendors, and some smaller vendors

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

NGIS in Operation

Cloud

LBand

Station Equipment

NGIS Equipment

PBS

VPN

Demod Reception/Deletion/Server

4 TB

Request Automation

TrafficServerConfirmation

ArrivalNotice

TransferCommand

Monitor &Resend

OfferSchedule

FTP / CIFS

Translation(if needed)

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

MXF Format Woes

• MXF can wrap many different types of audio and video essence

• There are a number of ways that variable size edit unit essence can be indexed

• MXF has ten different “Operational Patterns” (OPs)

• MXF can carry a wide range of descriptive metadata schemes

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

MXF – AS/PBS

• An MXF Application Specification for PBS• Base Requirements:

– Single file per program distribution mechanism.

– Direct play back (or import) into MXF compatible servers

– Otherwise easy to translate into non-MXF compatible servers

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

AS-PBS Development

• Began in 2004 based on “AS-CNN”

• Five key server vendors to public television initially involved

• Expanded to include other server and translation vendors

• Iterative process w. teleconferences and email distribution

• SD targeted first

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

MXF/AS-PBS Essence

• Video essence type:– MPEG-2 4:2:0

• Video bitrate:– 8 Mbps

• Audio essence type:– Uncompressed, 16-bit PCM audio in BWF

• VBI (CC/XDS):– SMPTE 334M ANC carried in SMPTE 436M for

MXF

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

MXF/AS-PBSMXF Features

• OP1a

• Partitions no longer than 30 minutes

• Index Table segments in partition after the Essence they index

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

MXF/AS-PBS Future

• To be defined:– HD Version– Archive version

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

MXF/AS-PBS

• Short “Golden Files” available

• Actual full-length program example to be distributed shortly (MPEG pre-charge issue being worked out)

• AS-PBS specification is available to those who want to see it, email:

tedwards@pbs.org

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

Library of Congress Stake

Carl Fleischhauer

National Digital Information Infrastructure and Preservation

Program

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

Video Reformatting at the National Audio-Visual Conservation Center

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

From SMPTE 390M

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

Concern for born-digital content

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

Born digital examples(not moving image)

GIS

Still imageMark Yankus

Web harvest

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

http://www.ptvdigitalarchive.org/

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

Preservation FormattingWorking Scorecard

• Interoperability very important• From-the-hip scorecards for

– Wrapper– Essence– Profiles/Application Specs– Metadata

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

Wrapper Scorecard

• No-wrapper vs. with-wrapper• Proprietary vs. open specification• Sizing up ISO/IEC 15444-3

Motion JPEG 2000

• AAF/MXF is attractive

• How settled in the community? Moderately

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

Picture Essence Scorecard

• MPEG (ITU-T) family– MPEG-2 (H.262)– MPEG-4 (H.263 but mostly H.264)– All I-frame possible (preservation value)

• JPEG 2000 family– Frame image encoding– Possible wrapper– Less adoption in still photography than some wish

• How settled in the community? Not bad, no need for one size to fit all

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

Profile/App Spec Scorecard

• Important part of MPEG family from an early day– Several ISO/IEC profiles and levels– SMPTE added one for 4:2:2 @ high level

• MXF is complex– Will benefit from application specification– Good example from PBS discussed today

• JPEG 2000 family– Digital Cinema Initiative has established two profiles– LC has one for its newspaper scanning project

• How settled in the community? In the early stages

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

Metadata Scorecard

• Metadata for management, support long-term preservation

• Technical characteristics– SMPTE RP-210 data dictionary (“parametrics”)– Public Broadcasting PB Core (“instantiation”)

• Preservation support– Includes preceding– Library community PREMIS project, e.g., fixity– Specifications, source code for readers/transformers

• How settled in the community? Not very

Dave MacCarnWGBH

Thomas EdwardsPBS

Carl FleischhauerLibrary of Congress

Preserving DigitalPublic Television

http://www.ptvdigitalarchive.org/