Live video capture of a GoPro HDMI stream to a Ninja

You have a GoPro HD Hero2 and an Atomos Ninja, a Cinedeck EX, or any other video field recorder that accepts a clean HDMI signal. Your GoPro HD Hero2 has a mini HDMI interface, but the user guide only refers to playing videos and photos to a TV set. Can you stream your video live to your Ninja? It depends — but with a few tweaks here and there, it’s possible.

Your GoPro HD Hero2 is first and foremost an action camera, and I don’t know about you, but I always associate the word “action” with me being the one who is making the effort — walking, running, jumping, driving… In those cases, you need your GoPro to be as lightweight and small as possible. The bulk of a Ninja dangling from your chest or attached to a helmet isn’t exactly going to contribute to spontaneity and it will seriously affect your stamina — unless your name is Arnold and you’re from Austria, of course.

But there’s nothing to keep you from using your GoPro HD Hero2 as a “static” action camera. It sure has good enough image quality and its field of view is large enough to capture more than an average video camera would. And when your GoPro is mounted on a tripod, a panorama pole like the Fanotec / Nodal Ninjas, or a Glidetrack or any other more or less static mechanism, wouldn’t it be nice to record straight into ProRes or DNxHD and benefit from these high-quality video formats?

I believe it would. But there are a few problems to overcome first. And if you’re in Europe, there’s one extra step to take before your Ninja (I don’t know about the Cinedeck EX) will recognise the GoPro’s signal.

Here is a step-by-step guide to having your GoPro HD Hero2 stream its video to a Ninja.

With OSD turned OFF.

But first, to make sure that you understand why you would do this, let me list the benefits:

  • A field recorder such as the Ninja, Samurai, Ninja-2, or Cinedeck EX, can record to a format with much higher bitrate and lower compression than the GoPro (or any compression-codec based video camera) can
  • Your Avid or Apple NLE (Media Composer, Symphony, Final Cut Pro X, Final Cut Pro 7…) can use the ProRes, DNxHD, or Uncompressed content you get from the recorder immediately without further transcoding
  • The higher bitrate of ProRes or DNxHD formats allow you to perform more dramatic colour grading and noise reduction.

And now the steps…

NOTE: I tested with a Ninja. If you own a Cinedeck EX, you should experiment with other settings as well.

PAL users should decide whether they insist on recording in PAL format or whether they are willing to switch (temporarily even) to NTSC. The Ninja does NOT recognise any of the GoPro’s PAL output. If your main output medium is the web — YouTube, Vimeo, etc. — you can switch to NTSC and won’t have to transcode to anything else. Any web video format is NTSC/PAL agnostic.

With OSD left ON.

However, if your aim is to broadcast your video for PAL TV, then you’ll either have to transcode to PAL before you start editing, or stick with GoPro’s H.264 format. If the higher bitrate is of any value to you, transcode to PAL using either Episode or Squeeze 8.x. They’re both capable of doing a great job.

Set the recording format to 720p or 1080p. The Ninja does not recognise WVGA at all — there’s simply no signal. It does recognise the 960 recording format, but reports it back as 1080p29.97.

The Ninja does make a difference between 720p29.97 and 720p60, so if you want to use slow motion anywhere in your clip, set the GoPro HD Hero2 to 720p60 and your Ninja will record at 60fps.

Go to the OSD setting on the GoPro HD Hero2. This is located under the tools menu in the More submenu. Turn OSD Off. If you leave it on, your Ninja will be recording the OSD icons from the GoPro.

That’s it. You can now start recording.

If you want to be sure the GoPro won’t turn itself off while you’re recording to the field recorder, and you don’t want to tamper with external batteries or power adapters, you should have the GoPro record to its SD as well.

However, for purely recording to the field recorder, the GoPro doesn’t need to be recording. You can even record to the Ninja or Cinedeck or whatever else you’re using with no SD card inserted in the GoPro HD Hero2 and it will work.

Comparable output quality with Cineform Studio Pro

If you look at the split-screen video sample link icon, the left is the ProRes 422HQ recording, while the right shows what the GoPro HD Hero2 made out of it, transcoded in Final Cut Pro X.

As you can see, the “GoPro version” is wildly saturated and leaves little room for de-noising and colour grading. The ProRes 422 HQ version looks less appealing at first sight, but allows for generous colour correcting, grading and noise reduction.

When I saw this, I was really curious to know if GoPro’s Cineform Studio Pro would be able to get the original GoPro footage closer to the ProRes footage. It seemed impossible, given that ProRes 422 HQ has a bitrate of over 100 Mb/sec and the H.264 file maxes out at 16 Mb/sec (Ed. – This is the bitrate before the Protune firmware becomes available; Protune will boost bitrates to 35Mbit/sec).

Yet, I could indeed produce a result that comes very close, although all colour grading and editing should best be done in Cineform Studio Pro, because — as I found out — grading the raw Cineform Studio transcoded file in Final Cut Pro X seemed to introduce new artefacts that simply aren’t there when you use the GoPro application.

I found the surefire way to get close to the ProRes result was to use a Log90 Encode Curve and a Cineon 1.7 Decode Curve.


One Reply to “Live video capture of a GoPro HDMI stream to a Ninja”

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