labmeeting - 20150831 - overhead and performance of low latency live streaming using mpeg-dash

NTUST - Mobilizing Information Technology Lab

Overhead and Performance of Low Latency Live Streaming using MPEG-DASH

Bouzakaria, N.; Concolato, C.; Le Feuvre, J.The 5th International Conference on Information, Intelligence, Systems and Applications, IISA 2014,

Advisor： Jenq-Shiou LeuStudent： Bing-Syuan WangDate： 2015/8/31National Taiwan University of Science and Technology

NTUST - Mobilizing Information Technology Lab 2

Outline• Introduction• Related Works• Live Dash Streaming Latency• Experimentations and Results• Conclusion


Introduction• HTTP Streaming technologies have been introduced recently to deliver

multimedia streams.

• An important standard in the field of HTTP streaming is the MPEG Dynamic Adaptive Streaming over HTTP (DASH) standard.

• HTTP/TCP vs RTP/UDP


Introduction• DASH is not initially adapted for low latency.

• Using “chunked-transfer encoding” over HTTP 1.1.

• Using low latency video coding tools.-H.264/MPEG-4 AVC standard.


Related Works• An HTTP streaming chain with typical segment duration of 1s would introduce

a delay in the order of 3s compared to RTP.

• With chunked-transfer encoding and with a proper download strategy, the latency depends on the duration of the HTTP chunks.

• The average bitrate loss of GDR(Gradual Decoding Refresh) compared to periodic IDR(Instantaneous Decoding Refresh) was between 11 and 17%


Related Works• Using the ISO Base Media File Format (lSOBMFF) in HTTP streaming

systems, including DASH.

• The goal of this paper:HTTP streaming using DASH with the combined usage of HTTP "chunked-transfer" encoding, GDR encoding and the ISO Base Media File Format.


Live DASH Streaming Latency• Basic DASH Latency

-Client, MPD(Media Presentation Description), MPD@availabilityStartTime

• Low Latency DASH-Segments are further divided in smaller parts and these parts delivered using HTTP chunks-availabilityStartTimeOffset (ASTO)


Live DASH Streaming Latency• Segment duration (ds)• Fragment duration (dc)• λ represents a margin introduced in the computation of ASTO to cope with

UTC mismatch between the client and the server


Experimentations• 1) Content generation:

-encoding, GDR, ISOBMFF, MPD

• 2) Content distribution: -”chunked-transfer” encoding

• 3) DASH client: -processing incomplete segments


Results


Conclusion• HTTP Streaming is the new approach for streaming video over the Internet, for

live and on demand cases.

• This paper described an implementation of a streaming system comprising a DASH live encoder generator, a DASH-aware web server and a DASH client.

• This paper validated the approach for very low latency streaming in local networks, with latency as low as 240 ms.

labmeeting - 20150831 - overhead and performance of low latency live streaming using mpeg-dash

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