moq C. Jennings Internet-Draft Cisco Intended status: Standards Track 21 October 2024 Expires: 24 April 2025 Serialization of MoQ Objects to Files draft-jennings-moq-file-00 Abstract This specification provides a way to save the meta data about each MoQ Object in one or more files as well as pointers to other files that contain the contents of the object. Separating of the meta data and payload data allow the payload data to remain in files that are used for other purposes such as serving HLS/DASH video. This format makes it easier to test and develop caching relays and create test data they can serve to client. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on 24 April 2025. Copyright Notice Copyright (c) 2024 IETF Trust and the persons identified as the document authors. All rights reserved. Jennings Expires 24 April 2025 [Page 1] Internet-Draft Moq Object Files October 2024 This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/ license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. JSON Meta Object . . . . . . . . . . . . . . . . . . . . . . 2 3. File Naming . . . . . . . . . . . . . . . . . . . . . . . . . 3 4. MOQT Track DataFile . . . . . . . . . . . . . . . . . . . . . 3 5. Playback . . . . . . . . . . . . . . . . . . . . . . . . . . 4 6. Example . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 6.1. Time Object Example . . . . . . . . . . . . . . . . . . . 4 7. IANA . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 8. Security Considerations . . . . . . . . . . . . . . . . . . . 4 9. Normative References . . . . . . . . . . . . . . . . . . . . 4 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 5 1. Introduction This specification defines a way of serializing the MoQ Objects defined in [MOQT] into files. The payload data and the meta data are separated into separate files to allow reuse of existing files with the payload data. 2. JSON Meta Object The .moq files consist of an array of one or more JSON objects. Each JSON object contains information about the MOQT object as well as pointers to the where the original data can be found. The follow fields are defined for JSON object: * namesSpace: Array of strings that have a Base64 encoded version of the data in each tuple of MOQT Track Namespace. * trackName: string with Base64 encoded version of the MOQT TrackName. * objectID: integer corresponding to the MOQT ObjectID * groupID: integer corresponding to the MOQT GroupID Jennings Expires 24 April 2025 [Page 2] Internet-Draft Moq Object Files October 2024 * subGroup: integer corresponding to the MOQT SubGroup * publisherPriority: integer corresponding to the MOQT Object publisherPriority * maxCacheDuration: integer corresponding to the MOQT maxCacheDuration * publisherDeliveryTimeout: integer corresponding to the MOQT publisherDeliveryTimeout * receiveTime: time was created or time original was received received by the relay. This is in milliseconds since the unix epoch. * dataFile: string with relative path name to the file that stores the MOQT Object, including header and its payload data. * dataOffset: number of bytes into file where objects starts ( 0 is first byte of file ) * dataLength: number of bytes of data in the object Any extension attributes should also be saved using a field name formed by the string "ext" then the base 10 integer representation of the extension type ID. 3. File Naming It is RECOMMENDED to use a URL encoding version of the FullTrackName with a suffix of ".moq" as the file name for the meta file. In this context FullTrackName is concatenation of Track Namespace with the TrackName, separated by "/". Optionally, the filename can be extended with information about group as needed. 4. MOQT Track DataFile When saving a whole MOQT Track to a file, a common way to do this would be to make one ".dat" file with all the object data and another ".moq" file with all the array of JSON object for each MOQT Object. An implementation can choose to have one file per MOQT group. In such a case, it does so by creating one metadata (".moq") file and one datafile (".dat") containing data for each object in the MOQT group. Jennings Expires 24 April 2025 [Page 3] Internet-Draft Moq Object Files October 2024 5. Playback Some use cases will want to just load a file into the relay as quickly as possible. Other may decide to remade the track name to a new track name publish the objects at a rate based on differences of the receiveTime of the JSON objects. 6. Example TODO More complete example 6.1. Time Object Example Data file named time1.dat contains: {"time":17294570764566} Metadata file contains: [ { "namesSpace": "bW9xOi8vbW9xLXRpbWUuYXJwYS90aW1lLXYxLw=", "trackName": "bWFjOjcyOjVjOmYwOjdjOmJmOmIw", "objectID": 0, "groupID": 123, "subGroup": 0, "publisherPriority": 0, "maxCacheDuration": 3600000, "publisherDeliveryTimeout": 60000, "receiveTime": 1729457464000, "dataFile": "time1.dat", "dataOffset": 0, "dataLength": 25 } ] 7. IANA TODO file extension registrations. 8. Security Considerations TODO 9. Normative References Jennings Expires 24 April 2025 [Page 4] Internet-Draft Moq Object Files October 2024 [MOQT] Curley, L., Pugin, K., Nandakumar, S., Vasiliev, V., and I. Swett, "Media over QUIC Transport", Work in Progress, Internet-Draft, draft-ietf-moq-transport-06, 19 September 2024, . Author's Address Cullen Jennings Cisco Email: fluffy@iii.ca Jennings Expires 24 April 2025 [Page 5]