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I've seen this post about what exactly "RAW" is.

My question is about the GoPro Hero 4, which comes with the Protune option for "advanced controls".


  • Is their "Camera_Raw" format a true RAW image format?
  • Since it's probably proprietary, will I be able to access the image data using third-party software?

In their description, GoPro uses the term "less compression", but I was under the impression that RAW meant NO compression at all.

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    It looks like CamRAW is access to uncorrected WB only. GoPro forums have a thread of interest: goprouser.freeforums.org/… – jdv Oct 19 '14 at 19:42
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    Raw does not mean "no compression at all", many raw formats are compressed - but with a lossless compression (like zip not jpeg) where there is no data loss - raw means unprocessed sensor output, it doesn't matter how that unprocessed data is stored in a file (compression, thumbnails, extra data in the file, etc.) – Nir Oct 19 '14 at 19:49
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    @Nir - RAW doesn't even mean that the compression is lossless, but rather that it hasn't been converted to image data yet. There are lossy RAW formats out there. RAW data just means that it describes the actual values captured by the sensor prior to applying any processing. The individual photosites are actually monochrome and get color from a pattern of colored filters over them. – AJ Henderson Oct 20 '14 at 6:02
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Camera raw sounds like it is effectively similar to RAW because it is describing the light data without any corrections. What comes in on the sensor is written out, but it does sound like it may be applying the filter, just using a mix of 1:1:1 for the color resolution. It's theoretically possible to work backwards from this to the full colors, but you may lose some bit depth if it goes from more than 8 bit sensor read out to 8 bit color encoding. Possibly even worse if it is encoding to 4:2:0 or 4:2:2.

The net effect of shifting color on this kind of a recording would be that there would be fewer total colors described after applying your corrections since you discard a portion of the possible colors that could be described by the format. (Where as your more traditional RAW doesn't discard any data, so you can be more selective about what you want to remove when you reduce the bit depth later in the process.)

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I believe the GoPro Hero 4 records in the h.264 format which is contained inside the MP4 Format. This codec is a Compression format and dependant on the recording bitrates.

h.264 is a universally accepted format that Allows for very large files to be compressed with minimal loss to the original content. The compression is dependant on the bitrate used; the higher the bitrate, the larger the file, and the lower the bit rate, the smaller the file. Satellite TV channels, although 1080p @24 FPS, are of a fairly low bitrate as they need to fit the bandwidth available. However, even then, sometimes images come across as blocky.

A Raw Image at full Bitrate will definitely be larger than the MP4 Image and taking into consideration, you can't have a video camera that can only take a few minutes of Film, the bitrate needs to be reduced to allow for longer footage.

If the Hero 4 is as good as the Hero 3, the loss of quality will not be something that will be noticeable and as good as if no compression had taken place.

Regarding editing, h.264/MP4 is pretty much the choice of all editing packages now. You may be required to install the latest version of Quicktime to ensure you have the latest codecs.

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    I wouldn't say that h.264 id a format "of choice" for editing packages. While it is a great delivery codec it isn't a good choice for editing. – stib Oct 20 '14 at 4:07
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    I stand corrected regarding my choice of words. h.264 is so common nowadays that one should not have an issue – Abdul N Quraishi Oct 20 '14 at 12:04
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    anq - you can edit your answer to include this. That may earn you upvotes... – Dr Mayhem Dec 19 '14 at 14:07

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