External video recorders improve video recording quality
This is part four in a five part series listing my picks for the top five video production industry news stories for 2011.
At NAB two types of solutions to replace tape-based workflows were presented. Both improved video quality dramatically. Externals HD recorders will be featured in with this selection and the other solution will be unveiled in part 5.
The problem with both tape based and internal codec video recording is that there just are not enough bits to go around and long GOP codecs are lossy and don’t hold-up well when you colour correct or key and re-encode. This is mostly because the internal codecs aren’t able to record all the detail with a limited bitrate but a contributing factor is that small sensor video cameras don’t natively resolve HD video and the processing required to scale the video from non-HD sensors results in a very noisy image.
Some higher-end video cameras (Sony XDCAM and Canon XF300) have higher bitrate recording options, but even though they double the bitrate of entry level professional video cameras, they still don’t have a high enough bitrate to handle both the detail and noise from tiny 1/3” and ½” sensors.
One solution is to record the video signal from the video camera’s HDMI or HD-SDI outputs on an external recorder that uses a much higher bitrate intraframe codec. The benefit of recording an HDMI or HD-SDI video signal is that these outputs leave the video camera BEFORE the signal is compressed for internal recording. This is why a live output on a monitor looks better than the recording – the recording is compressed but the live output isn’t.
Atomos was the first to bring affordable external recorders to market with their Ninja HDMI recorder and Samurai HD-SDI recorder. Both launched with the ProRes codec and later added the DNxHD codec for native Avid video editing. ProRes can be edited natively on both PC and MAC video editing software. I only point this out because ProRes is an Apple Codec and many video professionals don’t realize that Adobe Premiere Pro has worked on both the Mac and PC since CS3 in 2007. Similarly, many don’t realize that ProRes also works on the PC. Aja was technically first with an external recorder but their KiPro and newer KiPro Mini have much higher price points. Several other manufacturers launched HDMI and/or HD-SDI recorders in 2011 as well.
The nice thing about external HDMI video recorders is that they can improve the video recording quality on even older HD video cameras, as long as they have an HDMI or HD-SDI video output. I was an early adopter of the Atomos Ninja and I noticed that footage from my Sony Z7U video camera that I recorded on the Ninja was significantly higher in detail and overall quality when I was editing. This higher video quality carried over to my encodes as well but I would say this time the difference was even more dramatic. It is better to start off with a great video recording than it is to take a lossy video recording and convert it to a higher quality codec on export.
External HDMI and HD-SDI video recorders improve video recording quality and are my #4 video production industry trend of 2011.
Stay tuned for my fifth and final selection.