Video optimization

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Video optimization refers to a set of technologies used by mobile service providers to improve consumer viewing experience by reducing video start times or re-buffering events. The process also aims to reduce the amount of network bandwidth consumed by video sessions. [1]

Contents

While optimization technology can be applied to videos played on a variety of media-consuming devices, the costliness of mobile streaming and increase in mobile video viewers has created a very high demand for optimization solutions among mobile service providers. [2]

When streaming over-the-top (OTT) content and video on demand, systems do not typically recognize the specific size, type, and viewing rate of the video being streamed. Video sessions, regardless of the rate of views, are each granted the same amount of bandwidth. This bottlenecking of content results in longer buffering time and poor viewing quality. [3] Some solutions, such as upLynk and Skyfire’s Rocket Optimizer, attempt to resolve this issue by using cloud-based solutions to adapt and optimize over-the-top content. [4] [5] [6]

History

The spike in mobile video streaming has come about as a result of the development of the smartphone. Smartphones registered a 5% to 40% market penetration between 2007 and 2010 in the United States. [7] In the third quarter of 2011, smartphone sales increased by 42% from 2010. [8]

Mobile operators are facing an explosion in wireless data use, which is projected to grow 18-fold from 2011 to 2016 per the latest Cisco VNI forecast. [9]

With the use of mobile devices increasing so rapidly, and almost half of the traffic on mobile internet networks being accounted for by video sessions, mobile service providers have begun to recognize the need to provide higher quality video access while using the lowest possible bandwidth. [8] [10]

With the release of the iPhone 5 in September 2012, it has been predicted that LTE networks might experience decreased data speeds as streaming multimedia begins to tax the 4G network. [11] Cloud-based content optimizers that reduce the strain of over-the-top multimedia streaming could provide potential relief to mobile providers. [4] [12]

Techniques

With the recent studies, it is evident that the average attention span of the web audience is gradually decreasing. [13]

Pacing

A variety of techniques used for reducing traffic over a mobile network infrastructure is called pacing. Pacing is a special form of rate limiting, where traffic delivery to a device is slowed down to a point, that "just in time" delivery takes place. The idea behind pacing is to avoid traffic bursts and even the data flow. If an object is delivered in its entirety, pacing provides no benefit. Where pacing can offer savings is when the object is "abandoned" part way through. When abandonment occurs, the portion of the object left in the receiving device buffer is effectively wasted. [3] [14]

Transrating

Another technique used in video optimization is known as video transrating, which involves modifying the video input stream. This modification is accomplished through an analysis of either "content" (to determine if bit rate on a particular video can be lowered without altering viewing quality), "device" (to recognize a specific streaming device and reduce bit rate based on resolution and screen size), or "network" (in which conditions of the network are estimated and adjustments in bit-rate are made to accommodate to varying network speeds without detracting from viewing experience). Average transrating savings are typically less than 30% per video. [3] Transrating only allows modification to video quantization parameters and does not allow for modifications to the video resolution, codec, and other parameters. [15]

Transcoding

In contrast to transrating, transcoding converts data from one encoding to another. The two-step process of decoding and recoding digital media is typically performed to accommodate for specific target devices or workflows, but it can also be utilized for low-grade streaming optimization. [15] [16]

Full transcoding

Full transcoding offers optimization rates of 60-80% per video by completely decoding and recoding digital media while allowing for changes in codec and resolution. [3] [13] [15] The flexible conversion techniques associated with full transcoding result in higher optimization savings without impacting the quality of the original media. [16] [17] While full transcoding is more taxing on central processing units than transrating, there are cloud-based solutions, such as Skyfire, that allow network architectures with inexpensive CPUs to utilize full transcoding. [4] [15] [16]

Adaptive bitrate techniques

Adaptive bitrate (ABR) video streaming technology was implemented to solve some of the challenges with streaming high bitrate videos.

Videos streamed using traditional formats such as progressive download and RTSP have a common challenge; any given video must be encoded at a specific target bitrate (e.g., 500 kbps) – and that is the bitrate regardless of the access network over which it is delivered.

If the chosen target bitrate is too high, the video will not be delivered smoothly over lower-speed networks and there will be slow start times and re-buffering throughout the video. Even on fast networks like LTE 4G, slow start times and re-buffering will occur during times of congestion or high network utilization.

If the chosen bitrate is low, on the other hand, the video quality will be lower – thereby reducing the customer’s quality of experience.

There are a number of ways of dealing with these challenges. One way is to take the YouTube approach. YouTube uses HTTP progressive download, and makes multiple versions of the video available at different resolutions and bitrates. Users themselves can then select the quality / bitrate that works best for them. If stalling or rebuffering occur, then can select the next lower resolution and continue viewing the video.

Adaptive bitrate effectively automates these resolution / quality adjustments on behalf of the user. Each ABR video is encoded at multiple bitrates, each broken into "chunks" of varying lengths (e.g., Apple’s HTTP Live Streaming generally uses 10s chunks). If network bandwidth is insufficient to deliver the video at this bitrate, the client will request the next "chunk" to be at a lower bitrate; quality of video will be reduced, but re-buffering will be avoided. Conversely, if the network can deliver at higher than the current bitrate, the client will request the next chunk to be at a higher bitrate, and quality will increase. [18] [19] [20]

Cloud

A newer approach is to perform video and multimedia optimization in "the cloud" – data centers either operated by the service provider or by a third party. The major benefits of this technique are that it allows smoother bit rate adaptation and utilizes transcoding and caching methods to distribute resources only when and where they are needed. [14]

Related Research Articles

A codec is a device or computer program which encodes or decodes a data stream or signal. Codec is a portmanteau of coder/decoder.

Digital video is an electronic representation of moving visual images (video) in the form of encoded digital data. This is in contrast to analog video, which represents moving visual images in the form of analog signals. Digital video comprises a series of digital images displayed in rapid succession.

Video on demand Systems which allow users to select and watch video or listen to audio content on demand

Video on demand (VOD) is a media distribution system that allows users to access videos without a traditional video playback device and the constraints of a typical static broadcasting schedule. In the 20th century, broadcasting in the form of over-the-air programming was the most common form of media distribution. As Internet and IPTV technologies continued to develop in the 1990s, consumers began to gravitate towards non-traditional modes of content consumption, which culminated in the arrival of VOD on televisions and personal computers.

In telecommunications and computing, bit rate is the number of bits that are conveyed or processed per unit of time.

Transcoding is the direct digital-to-digital conversion of one encoding to another, such as for movie data files, audio files, or character encoding. This is usually done in cases where a target device does not support the format or has limited storage capacity that mandates a reduced file size, or to convert incompatible or obsolete data to a better-supported or modern format.

Evolution-Data Optimized

Evolution-Data Optimized is a telecommunications standard for the wireless transmission of data through radio signals, typically for broadband Internet access. EV-DO is an evolution of the CDMA2000 (IS-2000) standard which supports high data rates and can be deployed alongside a wireless carrier's voice services. It uses advanced multiplexing techniques including code-division multiple access (CDMA) as well as time-division multiplexing (TDM) to maximize throughput. It is a part of the CDMA2000 family of standards and has been adopted by many mobile phone service providers around the world particularly those previously employing CDMA networks. It is also used on the Globalstar satellite phone network.

Streaming television Distribution of television content via the public internet

Streaming television is the digital distribution of television content, such as TV shows, as streaming media delivered over the Internet. Streaming TV stands in contrast to dedicated terrestrial television delivered by over-the-air aerial systems, cable television, and/or satellite television systems. The use of streaming online video and streaming television is concentrated on streaming video on demand platforms such as Netflix, iWantTFC, Tubi, Crackle, Hulu, Amazon Prime Video, HBO Max, Vudu, Showmax, Peacock, Disney+, Apple TV+, BET+, and Paramount+.

Adaptive Multi-Rate Wideband (AMR-WB) is a patented wideband speech audio coding standard developed based on Adaptive Multi-Rate encoding, using similar methodology as algebraic code-excited linear prediction (ACELP). AMR-WB provides improved speech quality due to a wider speech bandwidth of 50–7000 Hz compared to narrowband speech coders which in general are optimized for POTS wireline quality of 300–3400 Hz. AMR-WB was developed by Nokia and VoiceAge and it was first specified by 3GPP.

Α video codec is software or a device that provides encoding and decoding for digital video, and which may or may not include the use of video compression and/or decompression. Most codecs are typically implementations of video coding formats.

Mobile web

The mobile web refers to browser-based World Wide Web services accessed from handheld mobile devices, such as smartphones or feature phones, through a mobile or other wireless network.

HD Lite is the re-transmission of a particular HDTV channel at reduced picture quality compared to the source.

Mobile broadband

Mobile broadband is the marketing term for wireless Internet access via mobile networks. Access to the network can be made through a portable modem, USB wireless modem, or a tablet/smartphone or other mobile device. The first wireless Internet access became available in 1991 as part of the second generation (2G) of mobile phone technology. Higher speeds became available in 2001 and 2006 as part of the third (3G) and fourth (4G) generations. In 2011, 90% of the world's population lived in areas with 2G coverage, while 45% lived in areas with 2G and 3G coverage. Mobile broadband uses the spectrum of 225 MHz to 3700 MHz.

Uncompressed video is digital video that either has never been compressed or was generated by decompressing previously compressed digital video. It is commonly used by video cameras, video monitors, video recording devices, and in video processors that perform functions such as image resizing, image rotation, deinterlacing, and text and graphics overlay. It is conveyed over various types of baseband digital video interfaces, such as HDMI, DVI, DisplayPort and SDI. Standards also exist for the carriage of uncompressed video over computer networks.

A mobile content delivery network or mobile content distribution network is a network of servers - systems, computers or devices - that cooperate transparently to optimize the delivery of content to end users on any type of wireless or mobile network. Like traditional CDNs, the primary purpose of a Mobile CDN is to serve content to end users with high availability and high performance. In addition, Mobile CDNs can be used to optimize content delivery for the unique characteristics of wireless networks and mobile devices, such as limited network capacity, or lower device resolution. Added intelligence around device detection, content adaptation can help address challenges inherent to mobile networks which have high latency, higher packet loss and huge variation in download capacity.

Adaptive bitrate streaming is a technique used in streaming multimedia over computer networks. While in the past most video or audio streaming technologies utilized streaming protocols such as RTP with RTSP, today's adaptive streaming technologies are almost exclusively based on HTTP and designed to work efficiently over large distributed HTTP networks such as the Internet. It works by detecting a user's bandwidth and CPU capacity in real time and adjusting the quality of the media stream accordingly. It requires the use of an encoder which can encode a single source media at multiple bit rates. The player client switches between streaming the different encodings depending on available resources. "The result: very little buffering, fast start time and a good experience for both high-end and low-end connections."

Dynamic Adaptive Streaming over HTTP (DASH), also known as MPEG-DASH, is an adaptive bitrate streaming technique that enables high quality streaming of media content over the Internet delivered from conventional HTTP web servers. Similar to Apple's HTTP Live Streaming (HLS) solution, MPEG-DASH works by breaking the content into a sequence of small segments, which are served over HTTP. Each segment contains a short interval of playback time of content that is potentially many hours in duration, such as a movie or the live broadcast of a sport event. The content is made available at a variety of different bit rates, i.e., alternative segments encoded at different bit rates covering aligned short intervals of playback time. While the content is being played back by an MPEG-DASH client, the client uses a bit rate adaptation (ABR) algorithm to automatically select the segment with the highest bit rate possible that can be downloaded in time for playback without causing stalls or re-buffering events in the playback. The current MPEG-DASH reference client dash.js offers both buffer-based (BOLA) and hybrid (DYNAMIC) bit rate adaptation algorithms. Thus, an MPEG-DASH client can seamlessly adapt to changing network conditions and provide high quality playback with few stalls or re-buffering events.

Skyfire is a software company founded in 2007, and acquired by Opera Software ASA, now Otello Corporation, in 2013. In 2015, the company became the Network Solutions division of Opera, and ceased using the Skyfire brand name. They offer network optimization technologies including video optimization and monetization tools for carriers. Skyfire discontinued its Skyfire Web Browser in 2014 in order to consolidate its focus on its mobile operator technology. Skyfire was funded by venture capital, and was acquired by Opera Software ASA in March 2013.

In the fields of broadcasting and content delivery, multiscreen video describes video content that is transformed into multiple formats, bit rates and resolutions for display on devices such as televisions, mobile phones, tablets and computers. Additional devices may include video game consoles such as the Xbox 360, or internet enabled television.

An online video platform (OVP), provided by a video hosting service, enables users to upload, convert, store and play back video content on the Internet, often via a structured, large-scale system that may generate revenue. Users generally will upload video content via the hosting service's website, mobile or desktop application, or other interface (API). The type of video content uploaded might be anything from shorts to full-length TV shows and movies. The video host stores the video on its server and offers users the ability to enable different types of embed codes or links that allow others to view the video content. The website, mainly used as the video hosting website, is usually called the video sharing website.

JPEG XS is an interoperable, visually lossless, low latency and lightweight image and video coding system that targets mezzanine compression within any AV application. Applications of the standard include streaming high quality content for virtual reality, drones, autonomous vehicles using cameras, gaming, and broadcasting. In this respect, JPEG XS is unique, being the first ISO codec ever designed for this specific purpose. JPEG XS, built on core technology from both intoPIX and Fraunhofer IIS, is formally standardized as ISO/IEC 21122 by the Joint Photographic Experts Group with the first edition published in 2019. Although not official, the XS acronym was chosen to highlight the eXtra Small and eXtra Speed characteristics of the codec. Today, the JPEG committee is still actively working on further improvements to XS, with the second edition scheduled for publication and initial efforts being launched towards a third edition.

References

  1. ↑ John Giere (October 16, 2012). "Reality Check: The role of video optimization in developed versus emerging markets". RCRWireless. Retrieved November 12, 2012.
  2. ↑ Gareth Spence (February 21, 2011). "Are we closer to solving the mobile bandwidth crunch?". ADVA Optical Networking. Retrieved November 12, 2012.
  3. 1 2 3 4 "Mobile Video Optimization: Concept and Benefits" (PDF). Tellabs Operations Inc. Retrieved November 12, 2012.
  4. 1 2 3 Jeff Glueck (September 19, 2012). "How Operators Can Prepare Their Networks for the iPhone 5". SkyFire. Retrieved November 12, 2012.
  5. ↑ Ricardo Bilton (October 11, 2012). "Skyfire gets another $10M to ease network data strain". VentureBeat. Retrieved November 12, 2012.
  6. ↑ Ricardo Bilton (October 11, 2012). "Trouble managing Internet video? Skyfire raising money, expanding". MedCity News. Retrieved November 12, 2012.
  7. ↑ Sebastian Anthony (May 9, 2012). "Smartphones set to become the fastest spreading technology in human history". ExtremeTech. Retrieved November 12, 2012.
  8. 1 2 "Gartner Says Sales of Mobile Devices Grew 5.6 Percent in Third Quarter of 2011; Smartphone Sales Increased 42 Percent". Gartner. November 15, 2011. Retrieved November 12, 2012.
  9. ↑ "Cisco Visual Networking Index Forecast Projects 18-Fold Growth in Global Mobile Internet Data Traffic From 2011 to 2016". Cisco - The Network. February 14, 2012. Retrieved November 12, 2012.
  10. ↑ "Video Optimization". Flash Networks. Retrieved November 12, 2012.
  11. ↑ Chris Ziegler (September 13, 2012). "Will LTE buckle under the iPhone 5's weight?". The Verge. Retrieved November 12, 2012.
  12. ↑ Greg Kumparak (July 28, 2011). "Skyfire's VideoQ Lets You Save Flash Videos To Watch On Your iPhone Later". Tech Crunch. Retrieved November 12, 2012.
  13. 1 2 "What Is The Main Purpose Of Video Advertising Services?". Adopsmind.com. June 28, 2012. Retrieved November 12, 2012.
  14. 1 2 "User-aware Video Optimization". Mobixell. Retrieved November 12, 2012.
  15. 1 2 3 4 "SkyFire Whitepapers". SkyFire. Retrieved November 12, 2012.
  16. 1 2 3 Daniel Taylor (June 22, 2010). "An Overview of Audio and Video Transcoding". Longtail Video. Retrieved November 12, 2012.
  17. ↑ Ivory King (October 16, 2012). "For carriers, video optimization can be an answer to "mobile warming"". Atelier. Retrieved November 12, 2012.
  18. ↑ Kelly Hodgkins (December 16, 2011). "Skyfire: companies need to do a better job streaming mobile video". IntoMobile. Retrieved November 12, 2012.
  19. ↑ "Skyfire Report reveals that Adaptive Bit Rate Usage is Still Low". CDN-Advisor. December 18, 2012. Retrieved November 12, 2012.
  20. ↑ "Only 18% Using Adaptive Streaming, Says Skyfire Report". Streaming Media. December 14, 2011. Retrieved November 12, 2012.
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