Cracking the encoder/decoder code

TV Technology

With software solutions now in abundance, encoding and decoding have come a long way from the metal boxes of a decade ago. But is software always better?

http://www.tvtechnologyeurope.com/buyers-guide/cracking-the-encoder-decoder-code/01176

The need to deliver to more and more devices is complicated by the rise of video quality expectations for 'TV everywhere'. Consumers want to experience ever-better HD or UHD quality on any screen. These higher expectations are intimately linked with the question of ensuring delivery to a maximum number of consumers through low bandwidth mobile networks where the threat of limited access, slow playback capabilities and unreliable connections is constantly looming.

Multi-screen encoding and transcoding solutions are key to helping broadcasters, programmers, content owners and their multichannel video programme distributors (MVPDs) – such as cable, DTH satellite or telecoms operators – and OTT players to overcome the numerous challenges of delivering reliable, high quality video content to a wide variety of devices.

For ATEME, the proliferation of those screens across different networks – payTV, OTT, and 3G/4G – calls for an increasing number of video formats to be produced at the video head end. Its multi-screen solutions address those challenges with a particular focus on video quality at the lowest bitrates.

Its TITAN Live is a real-time multi-channel/format encoder claiming the highest bandwidth efficiency on the market powered by home-grown encoding technology. TITAN embeds up to 48x3G-SDI inputs and can also receive IP sources from satellite, making it a convergent solution for complex video head ends.

The top two buying criteria for broadcast customers with multiplatform distribution needs are simplicity of use and flexibility. “Getting more done with the same, or even fewer, resources requires software that is easy to use and capable of shielding the complexity of the underlying operation,” says Mark Senecal, manager of product management, Imagine Communications. “In terms of flexibility, broadcast customers require solutions that are able to adapt to new platform launches with new codecs or additional processing requirements, without making compromises on any platform.”

Imagine's key products are SelenioFlex Live addressing multiplatform delivery for linear streams and SelenioFlex File, optimised for handling file-based workflows. The underlying architecture is Zenium, the company's modular software that enables customers to use multiple codecs to address the specific application and desired platforms for delivery, whether for SD, HD or UHD, to any device.

But is a software solution always the answer? There are two sides to this story. It is possible to make the case that with a fixed receiver platform (such as a Roku box) it can be more economical to include hardware decode. But most vendors contend that using software to encode is a much better solution.

“By their very nature, software solutions are more flexible than the hardware equivalent, as they can be updated 'on the fly' without worrying if the hardware acceleration has enough horsepower to accommodate the change,” says Paul Turner, vp of enterprise product management, Telestream. “And the one thing that is constant in this industry is change – new formats are coming out all the time.”

Telestream offer a version of Vantage targeted at the creation of multiscreen assets. It also offers GPU-accelerated Lightspeed encoding. Explains Turner; “The principle here is that if each individual job can complete more quickly via our Lightspeed servers, then the customer can achieve more throughput per hour, with lower CDN costs per delivered hour, all of which contributes to an improved bottom line for our customers.”

But Matrox notes that purpose built, hardware-based encoders for live applications can sometimes offer an advantage. A small, embedded encoder is less exposed to network and internet risks than a general-purpose computing platform running software, says Dan Maloney, senior technical marketing manager.

“At the transcoder level, software will almost always be the preferred solution from a flexibility standpoint, but hardware will come into play when executing latest-generation video processes that surpass the capabilities of standard CPUs. For example, 4Kp60 H.264 Long GOP encoding requires hardware (as provided by Matrox M264 H.264 encoding accelerator) particularly if quality and real time encoding are important.”Clearly, if a hardware solution is selected, be aware that these devices cannot easily be reprogrammed should tech trends change. “Particularly when you need more power for peak seasons, scalability and flexibility of solutions needs to be taken into consideration,” says Jiri Matela, CEO of Czech firm Comprimato. “For this, a software solution is more appropriate.”

Comprimato claims to market “the fastest, standard compliant, JPEG2000 software encoder and decoder” around. Its software codec leverages the performance of GPUs and CPUs to speed up video and image compression and can be used in combination with the video processing GStreamer framework. Comprimato says its codec helps cut infrastructure costs by 70 percent, while reducing development cycles by 50 percent therefore enabling new revenue streams such as UHD video in real-time, High Dynamic Range (HDR) and High Frame Rate (HFR) video.

“By separating the software and hardware aspects of these solutions, it is possible for broadcasters to have different budget cycles for the two components for a single application/solution,” says Tom Lattie, VP, market management at Harmonic. “Typically the software component has a very long lifecycle with minimal ongoing investment, usually in the form of a service level agreement. This allows the broadcaster to receive continuous innovation with little disruption and no significant incremental capital outlay. Conversely, broadcasters can replace lower cost general IT infrastructure components on a more frequent or as needed basis.”

Harmonic says that its Electra X advanced media processor is the industry’s first fully converged platform for broadcast and OTT delivery of SD, HD and UHD content. The appliance features real-time encoding of SD, HD and UHD media, integrated with high-quality branding and graphics, and reliable transport stream playout. Under the hood, the Electra X is driven by Harmonic's PURE compression, the company's proprietary encoding engine.

Harmonic’s Electra X3 was a key element in enabling NASA to deliver UHD video quality at minimum bandwidth, on its new NASA TV UHD channel, transmitted via the AMC-18C satellite. The Electra X encoding technology supports resolutions up to 2160p60 for broadcast and OTT multiscreen delivery. NASA and Harmonic have also begun discussions about adding high dynamic range (HDR) and expanded colour-space technologies to the channel as standards emerge.

“Clearly, broadcasters need an encoder that features codec diversity, offering support for formats such as MPEG-2 and AVC with a non-forklift path to HEVC,” offers Lattie. “The encoder should also support simultaneous generation and output of streams to enable traditional broadcast distribution as well as adaptive bitrate.”

With the industry transitioning to IP workflows, it is equally important that encoding/decoding devices support both IP and traditional SDI interfaces, giving broadcasters the flexibility to deploy in architectures today and migrate to IP when appropriate.