HTTP Streaming Survey and Gap Analysis draftzonghttpstreaminggapanalysis01 Ning

HTTP Streaming Survey and Gap Analysis draft-zong-httpstreaming-gap-analysis-01 Ning Zong 2020/10/2 HTTP Streaming bar Bo. F, IETF 79 th

Outline n A brief survey of existing HTTP streaming standards and implementations. n A brief summary of the existing work. n The gap between existing work and possible working scope in IETF. 2020/10/2 HTTP Streaming bar Bo. F, IETF 79 th

n n 3 GPP: Adaptive HTTP Streaming (AHS) Defines Media Presentation Description (MPD) to characterize the structure and features of a media presentation. Some important elements in a MPD include: q q q q q multiple "Period" element; multiple "Representation" element; "bandwidth" attribute in “Representation”; "start. With. RAP" attribute in “Representation”; "quality. Ranking" attribute in “Representation”; "Trick. Mode" element in “Representation”; "Segment. Info" element; "duration" attribute in “Segment. Info”; “URLtemplate“ element, or "Url" elements in “Segment. Info”; 2020/10/2 Media Presentation HTTP Streaming bar Bo. F, IETF 79 th

3 GPP: Adaptive HTTP Streaming (AHS) MPD Generating a list of URI pointed to the segments Segment request Segment MPD Update Segment request Segment Client 2020/10/2 Server HTTP Streaming bar Bo. F, IETF 79 th

Open IPTV Forum (OIPF): HTTP Adaptive Streaming n Technical Specification has been published and includes "HTTP Adaptive Streaming”, which adopts 3 GPP AHS as basis and adds support for MPEG-2 Transport Stream. 2020/10/2 HTTP Streaming bar Bo. F, IETF 79 th

MPEG: HTTP Streaming of MPEG Media n A series of proposals have been proposed to address the background, objectives, use cases and requirements of the transport of MPEG media over HTTP. n The IETF has received from MPEG two liaison statements for our information. No actions from the IETF side are requested or required. Both statements will appear shortly on the IETF's liaison website https: //datatracker. ietf. org/liaison/. 2020/10/2 HTTP Streaming bar Bo. F, IETF 79 th

W 3 C: Video related work n Focus on client implementation built into browser, e. g. , q q video playback support using script and html, push notification support using API, video support using Media fragments URI. Websocket API 2020/10/2 HTTP Streaming bar Bo. F, IETF 79 th

Microsoft: Smooth Streaming n Defines each chunk as an MPEG-4 fragment box and stores it within a contiguous MP 4 file for easy random access. The MP 4 files are classified into two kinds. One is *. ismv file containing video and audio. Another is *. isma containing audio only. n Server manifest file (*. ism) describes the relationships between the media tracks, bit rates and files on disk. Client manifest file (*. ismc) describes the available streams to the client: the codecs used, bit rates encoded, video resolutions, markers, captions, etc. n Client requests fragments by URL including quality level and fragment offset. Server looks up the MP 4 file and figures out which fragment box corresponds to the requested offset. Server extracts the fragment box and sends it over the wire to the client. 2020/10/2 HTTP Streaming bar Bo. F, IETF 79 th

Adobe: Dynamic HTTP Streaming n File packagers translates either on-demand media files or ingested live streams over Real Time Messaging Protocol (RTMP) into fragments and writes the fragments to F 4 F files. n The F 4 M manifest file format contains information includes codecs, resolutions, and the availability of files encoded at multiple bit rates. 2020/10/2 HTTP Streaming bar Bo. F, IETF 79 th

Apple: HTTP Live Streaming n Stream segmenter reads the Transport Stream from the local network and divides it into a series of small media files (. ts files) of equal duration, and creates an index file containing a play-list of the media files, as well as meta-data information. The index file is in . M 3 U 8 format. 2020/10/2 HTTP Streaming bar Bo. F, IETF 79 th

Summary of Existing Work Produce segment files and manifest Stream segmenter Construct URIs pointed to the segment files manifest Choose file to be requested based on adaptation Segment request Look up segment file Segment Continue requesting … … Server Intermediary Nodes Client All the intelligence in current HTTP streaming design resides on the server and client software, rather than the network transport. 2020/10/2 HTTP Streaming bar Bo. F, IETF 79 th

Gap Analysis Characteristic If satisfied by existing work Adaptation bit-rate Yes Playback control Yes Use existing cache, CDN Yes client pull model Yes server push model No Reliable transmission in network Yes Real-time support in network No Qo. E improvement (e. g. startup) No Qo. E monitoring No More intermediary node support No Multicast support for scalability No Based on the above gap list, we can discuss more about the potential working scope in IETF to improve the transport part of HTTP streaming system. 2020/10/2 HTTP Streaming bar Bo. F, IETF 79 th

Thank you 2020/10/2 HTTP Streaming bar Bo. F, IETF 79 th

References n 3 GPP: q q n OIPF q n q q q http: //learn. iis. net/page. aspx/626/smooth-streaming-technical-overview/ Adobe q n http: //www. w 3. org/TR/html 5/video. html#media-elements http: //www. w 3. org/TR/2010/WD-media-frags-20100624 http: //www. w 3. org/TR/eventsource/ Microsoft q n http: //mpeg. chiariglione. org/working_documents/explorations/mmt/http_uc. zip http: //www-itec. uni-klu. ac. at/~timse/research/httpstreaming/http_req. zip W 3 C q n http: //www. oipf. tv/docs/Release 2/OIPF-T 1 -R 2 -Specification-Volume-2 a-HTTP-Adaptive-Streaming-V 2_02010 -09 -07. pdf MPEG q n http: //www. 3 gpp. org/ftp/Specs/html-info/26234. htm http: //www. 3 gpp. org/ftp/Specs/html-info/26244. htm http: //www. adobe. com/products/httpdynamicstreaming/ Apple q q http: //developer. apple. com/library/ios/#documentation/Networking. Internet/Conceptual/Streaming. Media. Guide/ HTTPStreaming. Architecture/HTTPStreaming. Architecture. html http: //tools. ietf. org/html/draft-pantos-http-live-streaming-04 2020/10/2 HTTP Streaming bar Bo. F, IETF 79 th