FPGAs are flexible, reprogrammable chips which can do certain tasks faster than CPUs, for example, video encoding and other data-intensive tasks. Once the domain of expensive hardware broadcast appliances, FPGAs are now available in the cloud allowing for cheaper, more flexible encoding.
In fact, according to NGCodec founder Oliver Gunasekara, video transcoding makes up a large percentage of cloud work loads and this increasing year on year. The demand for more video and the demand for more efficiently-compressed video both push up the encoding requirements. HEVC and AV1 both need much more encoding power than AVC, but the reduced bitrate can be worth it as long as the transcoding is quick enough and the right cost.
Oliver looks at the likely future adoption of new codecs is likely to playout which will directly feed into the quality of experience: start-up time, visual quality, buffering are all helped by reduced bitrate requirements.
It’s worth looking at the differences and benefits of CPUs, FPGAs and ASICs. The talk examines the CPU-time needed to encode HEVC showing the difficulty in getting real-time frame rates and the downsides of software encoding. It may not be a surprise that NGCodec was acquired by FPGA manufacturer Xilinx earlier in 2019. Oliver shows us the roadmap, as of June 2019, of the codecs, VQ iterations and encoding densities planned.
The talk finishes with a variety of questions like the applicability of Machine Learning on encoding such as scene detection and upscaling algorithms, the applicability of C++ to Verilog conversion, the need for a CPU for supporting tasks.
The codec world is fragmenting. None of the new entrants on to the market is expected to ever gain the universal status that AVC enjoys. This panel from Streaming Media East takes a look at how to prepare for this.
The panel kicks off discussing the differences between AVC and HEVC, VP9 and AV1 and moves on to discuss the pros and cons of supporting multiple codecs. Tarek from Twitch explains its partial adoption of VP9 – the reasons that it makes sense but the overheads which it brings the business.
Vittorio Giovara from Vimeo explains their reasons for using HEVC including their drive to be able to encode and deliver 10-bit video. Ellation’s Subhrendu Sarakar makes the point that managing codec changes and bitrate changes needs to be done carefully to ensure viewers that notice the change understand them and don’t feel there has been a reduction of quality.
After a brief discussion of encoding strongly characterised video types such as anime and gaming, the conversation moves on to AV1 and migrating from VP9 and there is an audience question on HEVC licensing and the lack of use of SVC (Scalable Video Coding)
It’s now relatively well known that Twitch deployed VP9 using FPGAs rather than as a software encoder which was the only way to get the real-time speed at 1080p60. The panel discusses encoding speed both in the encoder and decoder for VP9 and AV1 then finishes with a Q&A from the audience.