Audio Catches Up: Online Video Rocks with Multichannel Audio
As movies move online and go mobile, sound gets some respect with updated codecs, more TLC, and a better attitude.
The next time you walk past the hollowed-out hulk of a Blockbuster store in your neighborhood, you’ll be reminded that there is a war going on. Actually, the format wars have been going on for decades now, but the debris left behind by the physical media era underscores how the battles have migrated to the virtual realm now. One of the defining characteristics of this epoch of the conflict, though, is that it’s becoming less about the origin of the content, or even the format it takes in its travels, and more about the places that it ends up. Streaming to an ever-widening selection of devices and platforms puts content under a variety of pressures, and while the HD video dogfights get all the glory, audio— media’s perennial underdog—has some pretty capable allies of its own.
“Streaming services like Vudu and others are realizing that a two-channel, low bit-rate audio stream with the video simply isn’t enough for their customers,” says Craig Eggers, senior manager of consumer electronics partner marketing at Dolby, who enumerates several of the partnerships that are applying Dolby Digital Plus to the audio components of their content streams, including Rovi and phone makers such as Nokia. “People are expecting to get a cinematic experience with their streamed video, even if a movie is being streamed to a mobile device, and the trick is to do that without taking bits away from the HD video,” he explains.
The streaming environment will get a long- term boost from the current administration’s plan to extend high-speed wireless internet service to 98% of Americans over the next 10 years. President Barack Obama has proposed investing $5 billion into a fund that will ensure fast wireless technology is made available to rural areas across the country. The Federal Communications Commission is looking to “repurpose” 120 megahertz of spectrum through incentive auctions where television broadcasters would voluntarily give up spectrum in exchange for a portion of the auction proceeds.
That expansion of the wireless spectrum will be needed to support the mobile devices that consumers and media are migrating to. According to IDC (International Data Corp.), smartphone manufacturers shipped 100.9 million devices in 4Q 2010, while PC manufacturers shipped 92.1 million units worldwide—meaning that smartphones actually outsold PCs for the first time ever. The number of smartphones sold in 4Q 2010 was up 87.2% from the 53.9 million sold in 4Q 2009. By contrast, 4Q 2010 PC shipments were up only 5.5% versus the same period in 2009. And this is where movies—and their sound—are going.
Audio-for-Video in Hand
Video on mobile devices is already entering the 3D realm—the LG Optimus, released in February, plays back and shoots in 3D—though audio for video remains mired mainly in stereo. But that’s rapidly changing. Earlier this year, MP3 developer Fraunhofer-Gesellschaft announced that it has partnered with Texas Instruments, Inc. (TI) to allow MPEG surround audio streaming on TI’s DSP platform. Using the technology, internet broadcasters and other streaming music services will be able to provide a surround audio experience at bitrates as low as 64Kbps for 5.1 channels. Surround audio’s six tracks are downmixed in the codec to a stereo pair plus a metadata track that provides the decoder with the proper time, coherence, and spatial and other parameters to re-create the surround field for the listener.
With consumers now expecting a multichannel audio experience with their entertainment content, regardless of the platform they view it on, others are entering that same arena. New Hampshire-based Akita Blue, Inc. creates and licenses digital audio software that expands stereo sound into discrete surround audio. The company’s Vector Engine upmix technology is an algorithm that accepts XML metadata that can be used to indicate the type of source material (e.g., stereo music, Lt-Rt encoded movie soundtrack), as well as detailed controls for channel extraction and cross- mixing. Content providers and streamers can determine the level of control they want over the audio for a picture, ranging from “set-and- forget” type controls for consumers to complete controls that are suitable for audio remastering engineers. The engine is productized as the Au7, designed for applications such as Internet TV and streaming devices under Windows and Linux. Other variants are targeted for automotive and set-top box applications.
“There’s a tremendous amount of interest to get all audio-for-video into a surround environment as simply and effectively as possible,” says Akita Blue CTO Jay Frigoletto. “The problem is, most of the infrastructure for streaming movies now is built for stereo.”
Frigoletto says that even Netflix, Inc. and iTunes, the biggest player in movie streaming and the world’s biggest music and video store, respectively, are hard pressed to deliver a true discrete multichannel audio experience, with the surround channels essentially interpolated using what he refers to as a “1970’s technology” such as phase shifting, smearing, and matrixing. Dolby Digital can handle a fully discrete surround soundtrack, but Frigoletto says that mobile applications don’t always offer the bandwidth needed to pass that through. “1080p is everywhere, even on handsets now, but getting 5.1 across is harder,” he says, referencing the perennial second-class status that many audiophiles believe sound is relegated to when it’s synced to picture.
When the Music’s the Thing
While streamed movies have been the biggest focus in the media recently, the reality is that music videos on iTunes, YouTube, and other streaming outlets remain the single largest category of audio-for-video entertainment content products. VEVO— which some describe as being a Hulu for music videos—is a music video website that’s been trying to elevate the sonic quality of the audio it streams. The year-and-a-half-old site, which gets content from Sony Music Entertainment, Universal Music Group, and EMI Group Ltd. (Warner Music, Inc. was initially reported to be considering hosting its content on VEVO but subsequently formed a rival alliance with MTV Networks) has approximately 23,000 videos available. VEVO president and CEO Rio Caraeff says that the sound quality is critical for the success of any streaming venture, music or otherwise. “We’ve seen that, historically, audio has never been prioritized over video,” he says. “Our studies have shown that if you take poorly compressed video but pair it with high-quality audio, people perceive the video to be of higher quality than it actually is. Conversely, if you have well- compressed video but it has poor quality audio, the overall perception of the video is diminished by viewers. The quality of the audio greatly affects the overall perception of the video experience.”