Pretty much everyone has been comfortable with the concept of streaming media for a while now, but the current global health crisis has forced everybody to become good at it—whether they’re tech savvy or not. As we rely on streaming platforms for more of our interactions, we are reminded that transmitting and receiving high-quality audio isn’t always the easiest thing, especially if we are hampered by fluctuating network conditions and services that weren’t designed to deliver enterprise-grade performance.
“High-quality audio in streaming really follows the same ground rules as production audio always has, which is good source equals good delivery,” said Dave Van Hoy, president, Advanced Systems Group, an AV design and integration firm headquartered in Emeryville, CA. Because audio transmission requires less bandwidth than video, audio-only streaming is less challenging. “You’ve got to consider, How does sound go from being physical sound waves at its source to being electronic, and how does that then get transmitted? If you can solve for that, then the chances are pretty good that you’re going to have a good audio experience.”
But synchronizing audio with streaming video is another matter. “It’s a much harder problem to solve for because oftentimes much of it is out of your control,” Van Hoy acknowledged. The issue becomes more complex when multiple participants in a livestream must interact—especially if the desired production values exceed the quality of an average conference call. “If I want to go beyond that, I would have to begin to apply more traditional broadcast production audio methodologies, including the idea of foldback, and being able to hear the program without latency.”
Eduardo Martinez, director of technology at StreamGuys, a content delivery network (CDN) and streaming provider headquartered in Bayside, CA, concedes that some broadcasters are constrained to using a laptop with software-based encoding, though he argues that this setup is not ideal. “In a perfect scenario, we like to see customers with dedicated appliances for streaming,” he said. “In our eyes, that [removes] a lot of the management headaches from a broadcaster’s perspective. You don’t have to worry about, if it’s a local PC [for example], somebody else messing with the encoding.” He added that there are solutions to suit a wide range of budgets.
Martinez said that the development of dynamic stream splicing software—such as the Intraplex solution offered by StreamGuys partner Gates Air—helps to maintain quality audio when network conditions threaten to produce jitter and packet loss. “With [dynamic stream splicing], we’re able to offer extra resiliency at a network level because we’re able to send two streams—either over the same network, or via two different internet service providers,” he explained. He points out that a growing number of audio products manufacturers offer solutions based on the SRT (Secure Reliable Transport) protocol. “It’s reliable because it’s a purpose-built protocol that allows users to combat things like jitter and packet loss on the network.”
This is significant, Martinez said, especially for broadcasters located in remote areas where network conditions are inconsistent. “[We work with] broadcasters in really remote areas like Alaska that make great use of these technologies because the networks can be a little bit unreliable at times,” he said. “Ensuring that you have those extra layers of redundancy on the ingest side of things ultimately ensures the robust transmission of audio.”
Another factor that has made streaming audio easier, according to Van Hoy, is the sophistication of modern mobile devices. He added that available tools don’t require content creators to be overly technical to produce programming. To address the challenges faced by those working from home, his company released remote production kits that facilitate production and streaming, including lighting, laptops, microphones, and DSLR cameras with desktop tripods and prompters; the kits are configured with less-technical users in mind.
“Part of it is about giving people decent cameras and lights so they don’t look like they’re shooting in a cave, but the other part is making sure people are cognizant of audio, that they’re using a good microphone, and that they’re aware of the acoustics of the space they’re in,” Van Hoy explained. “It’s helping people deal with their acoustic environments and their microphones so that the audio starts out good––because if it doesn’t start good, it never gets better. It can’t.”
TVU Networks, an IP video solutions developer headquartered in Mountain View, CA, recently incorporated new audio mixer functionality into its TVU Producer 3.0 cloud production platform. The feature, which enables audio mixing to be done separately from video and graphics operation, allows for the monitoring of each video/audio production feed, adjustment of all audio input levels as well as master output, gain adjustments for each channel, channel assignment for each group for management of multiple sources, and individual muting for each channel.
Paul Shen, CEO at TVU Networks, noted that the audio mixer feature facilitates the audio production process for crew members who are confined to working from home (and thus stuck with the limitations of their residential internet connections) but are still responsible for producing high-quality broadcasts. “They have proxy audio so they can hear and assess the quality of the production, and the full production is in the cloud in whatever broadcast quality is required,” he explained. “In audio mixing, one of the big challenges is ensuring that the quality is good without overburdening the infrastructure.” With the proxy approach, Shen said that high-quality audio can be achieved in low-bandwidth conditions.
While a great deal of collaboration, presentations, lectures, and performances rely on both aural and visual communication, Van Hoy noted that achieving good-quality sound strengthens the message, no matter what it is. “You can have great content that’s audio-only. It is almost impossible to have great content that is video-only,” he said. “The little bit of effort it takes to make sure you are starting with good signals is important and will make a huge difference in your final product, whether it’s a Zoom call or a broadcast across the airwaves of an entire country. It’s impactful.”