Exam Revision Flashcards
What does the SMPTE 2022 standard define?
- It is a suite of standards which describe sending video over an IP network.
- Uses Forward Error Correction.
- MPEG 2 and SDI are supported.
What is Key Lenth Value Coding and how does it address data in the file?
- The purpose of KLV is to segment information packets that are joined together as continuous bytes.
- A KLV is a triplet composed of a key which identifies what comes next, a length and the actual data.
- The structure of this means that should a decoder not understand the data which is outlined in the Key, it can skip over it using the designated length.
Explain the purpose of the MXF body.
- Contains the media essence and any additional metdata.
What does a HTTP Response include?
- The version of HTTP being used.
- A response status code that gives the result of the request.
- An English reason phrase describing the status code.
Why was Application Specification 02 (AS-02) developed?
- AS-02 was developed in order to enable content versions and inventories to be stored for delivery to different platforms and devices.
What are Mezzanine formats and how are they used?
- In keeping with Business Process Management (BPM), all ingested and contributed video formats are converted into a single mezzanine format.
- This is so that testing can be done on the footage far more efficiently, and to ensure that all NLE suites have the correct codecs, thus speeding up production.
- Industry has also adopted this phrase as a synonym for proxies, whereby compressed video (which is still sufficient to edit with) can be accessed in post production, following which the EDL can be applied to the uncompressed version of the video.
Define a Private Cloud.
The cloud infrastructure is operated solely for an organization. It may be managed by the organization or a third party and may exist on premise or off premise.
Explain the purpose of the MXF Footer.
- Contains file information that may not have been present when the heder was created.
- Explicitly signals the end of the file.
Who are Ontologies governed by?
- Resource Description Framework (RDF) and Web Ontology Language (OWL).
What is Horizontal Scaling?
- Horizontal scaling means that you scale by adding more machines into your pool of resources.
- Horizontal scaling means that you can clone the existing OS onto a new machine to add resources without having to force a reboot.
What is Forward Error Correction (FEC)?
- Forward error correction (FEC) is a special code for error detection and correction.
- The sender adds parts of the data again, this is called redundancy.
- In certain cases, the receiver can correct the error, without the need for a retransmission.
What does the MPEG 21 standard define?
MPEG-21 is based on two essential concepts
- Definition of a Digital Item (a fundamental unit of distribution and transaction).
- Users interacting with Digital Items.
In an ontology, what is a triple?
- A triple describes the instantiation of two classes which hold a relationship together.
- This takes the form of Subject –> Predicate –> Object.
What characteristics define Ontologies?
- Granularity: Extent to which the objects are precisely and formally defined.
- Formality: Extent to which the objects are described in a formal language.
- Coverage: Which percieved usage scenarios are covered by the ontology.
- Specificity: To what extent the objects are precisely defined.
What are the disadvantages of Audio Fingerprinting?
- The content must be unique, in the case of tv show intros and compilation episodes this is not the case.
- Can’t be done on a live tv show.
What is Audio Fingerprinting?
- This is method whereby content is identified through the analysis of the content’s audio frequency spectrum.
- From this, unique identifiers can be used to create a unique ID by which the content can be recognised.
- The fingerprint is robust and can still be recognisable despite background noise and variance in amplitude.
What does the MPEG 7 standard define?
- MPEG-7 is a multimedia content description standard, formally called the Multimedia Content Description Interface.
- A Description consists of a Description Scheme (structure) and the set of Descriptor Values (instantiations) that describe the Data.
- It uses XML to store metadata and can be attached to timecode in order to tag particular events. It can be used in tandem with MPEG 4.
Define a Community Cloud.
The cloud infrastructure is shared by several organizations and supports a specific community that has shared concerns (e.g., mission, security requirements, policy, and compliance considerations). It may be managed by the organizations or a third party and may exist on premise or off premise.
Explain the purpose of the MXF Partitions.
- Used to divide the file into defined entities.
- Can be used to cause files to conform to transmission requirements (file size).
- Defines the data sequence. (Header/Body Partition Packs).
- All files MXF only require a header partition.
What are the MXF OP Patterns?
Explain the concept of Linked Open Data (LOD).
- The web is traditionally html documents which are interconnected through http, whereas LOD is RDF semantically linked data on HTTP.
- The Open part means that is openly licensed and therefore freely usuable and available.
- Allows semantic connections to be made, typically interconnected RDF triples.
- Uses Uniform Resource Identifiers (URIs) to address/locate data.
- Searches promote linkages to relevant results for specific searches.
What is On-Demand Self-Service?
A consumer can unilaterally provision computing capabilities, such as server time and network storage, as needed automatically without requiring human interaction with each service’s provider.
Define a Public Cloud.
he cloud infrastructure is made available to the general public or a large industry group and is owned by an organization selling cloud services.
Use a diagram to explain the construction of an MXF file.
What are the common timecodes?
- Timecode is generally carried as a dedicated metadata item.
- Film 24fps progressive
- UK tv 25 fps interlaced.
- US tv 29.97 fps interlaced.
What does the SMPTE 2110 standard define?
- The transportation of uncompressed elementary streams over IP.
- Allows traffic shaping and delivery timing.
- Better for a production environment as audio doesn’t need to be embedded/de-embedded.
- Uses SMPTE 2059 for the clock sync.
- Uses AES67 for uncompressed audio.
- Uses RFC 4175 for RTP payload format for uncompressed video.
- Relies on AMWA’s NMOS IS-04, despite not being part of the standard.
What is the structure of an AAF file?
What do the Networked Media Open Specifications (NMOS) define?
- The goal is to provide open interoperability between suppliers of IP as a replacement for SDI.
- The Joint Taskforce-Netoworked Media (JT-NM) created the four layer Reference Architecture (RA) model.
- They did so to address interoperability in networked media environments as current standards don’t tackle control or application planes.
Draw a diagram detailing the contribution chain through playout.
