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H264 vs XAVC vs ProRes


Max Field

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Hey, forgive me if I screw up any terminology, was just trying to see where the XAVC format many Sony cameras like to record in stands between H264 and ProRes in terms of raw image quality and work-ability in post. I know I could read advertised data rates, but some things optimize better than others.

Let's say if I had a chart like this:
H264 ------------------------------------------------------------------------------------ProRes422
about where would you place XAVC?


Thanks, and sorry if this is a jumbled mess.

Edited by Max Field
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the better xavc varieties may be visually very similar looking in quality compared to the prores422 unless you underexpose the xavc camera a lot which may generate weird compression artifacts like blue dots flashing around. I haven't pixel peeped them side by side with material shot in the same situation (would require the same camera to record both at the same time which has not been practical yet in projects I do) . 

nowadays I shoot a lot with an external recorder on Prores422hq and it is slightly better quality than xavc especially if underexposed though will take significantly more storage spage.

So I would put it pretty close to the Prores422 on that scale if it is properly exposed. workability in post is pretty much the same in most situations I think though you may find differences if the material is not optimally shot. this is for the 300-400Mbps 4k/UHD xavc varieties... if you shoot the more compressed ones like the 100Mbps ones then there is lots more difference

Edited by aapo lettinen
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XAVC Class 300 feels pretty comparable to standard Prores422 in terms of overall image quality. I haven’t compared them side by side, but I feel like I’ve encountered compression artefacts in similar levels from both. 

Prores422HQ I’d put it a bit above standard XAVC. 

Both are mastering codecs though, and far above a delivery codec like h264.

Prores is self-contained and drag-and-drop though, which makes it VASTLY easier to deal with in post than XAVC. 

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XAVC is a proprietary codec developed by Sony for their cameras. Like Pro Res, it has many variations based on bandwidth, progressive segmented frame or i-Frame 8 bit or 10 bit and of course frame size up to 4k. XAVC is part of the MPEG 4 family which includes .h264 and .h265. It was developed specifically for camera originals due to the efficiency and quality of the codec.

.h264 is an open source variant of the same MPEG 4 codec, only in most cases companies only use the lower end version of it; Long GOP 8 bit 4:2:0. 

 Pro Res is an entirely different codec. Unlike the MPEG 4 codec's, Pro Res is a video-only codec like DNX and JPEG2000. Pro Res has been built from the ground up to be a CPU decoding and encoding codec. This way, the GPU can be used for processing and the CPU can be used for encoding/decoding. Apple is the developer of the software and it's meant specifically for post production, not for camera original. It's a very high bandwidth codec, with 12 bit 444 color with added alpha channel capabilities. It's distributed multi-threaded capability makes high bandwidth decoding possible on low-end computers, which can't be said about the MPEG 4 codec's. Some people get confused about DNX and Pro Res because they have very similar codec layouts. DNX is actually JPEG 2000 in design, even though Avid own the licensing. DNX is a GPU encoded and decoded codec, like JPEG2000. 

Pro Res and DNX are the top deliverable codec's for everything but theatrical, which require DCP's which are JPEG2000. Most everyone delivers in 10 bit 444 codec's and require AIFF or WAV multi-track audio. 

In terms of quality, 12 bit Pro Res XQ is the highest quality standard codec available. The DNXHR varant is identical, so those two would be placed side to side. XAVC-I 400Mbps 10 bit 4:2:2 which is the standard for most cameras, isn't even remotely close to the quality of Pro Res XQ, there is banding/bleeding on the Red and Blue channels and of course with a 10 bit image, there can be banding in the grayscale as well depending on resolution (4k is a lot better with this). So if 8 bit 4:2:0 Long Gop .h264 is the lowest codec, then I'd say 10 bit 4:2:2 XAVC-I is close to the top, but not quite there. 

Remember, bandwidth is the most critical aspect, so all of the lower end codec's can look pretty damn good at super high bandwidth, but sadly the developers don't let the software ramp up that much. They restrict it purposely. 

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19 hours ago, Max Field said:

So do all the Sony mirrorless cameras record to that XAVC-I codec internally? Or do they record to an even farther crushed codec?

None of the Sony Mirrorless cameras record XAVC-I, they all record XAVC-S which is the shitty Long GOP 8 bit 4:2:0 .h264 variant. 

The only cameras that record XAVC-I are some of the Canon C series and Sony F/FS series + F65 and Venice. 

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31 minutes ago, Tyler Purcell said:

None of the Sony Mirrorless cameras record XAVC-I, they all record XAVC-S which is the shitty Long GOP 8 bit 4:2:0 .h264 variant. 

The only cameras that record XAVC-I are some of the Canon C series and Sony F/FS series + F65 and Venice. 

What are the tiny cameras with big sensors that record to something better than H264 internally?? If the pocket had a super 35 sensor it'd be perfect for me.

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1 hour ago, Max Field said:

What are the tiny cameras with big sensors that record to something better than H264 internally?? If the pocket had a super 35 sensor it'd be perfect for me.

Sony and Canon purposely hinder their cheaper cameras so people will buy the more expensive cameras if they want "quality". Blackmagic doesn't have that problem, they don't have a huge model lineup to compete with. So the difference in the cameras is minimal. 

I'm perfectly happy with a smaller imager camera, it's way easier to work with. 

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XAVC is a pretty solid codec, especially on a camera like the FS7. I did a heavy grade on a doc that was shot on XAVC and it looked great!

https://www.youtube.com/watch?v=bIv3GNKjlr8&feature=youtu.be

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I also would like to add that I believe the primary reason S35 sensors on DSLR's have, up until recently, been 8 bit h.264 is essentially about computing power. We're asking a lot for a tiny camera body to record in 10 bit codecs. However, the new Fuji and Panasonic S35/FF mirrorless cameras are quite promising!

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As above.. big fuss about the Panasonic GH shooting 10 bit ,so why can't A7,s..but as AJ says the big difference is the Gh have a tiny sensor .. which makes it a lot easier to achieve ..  and alot of it is marketing blurb.. most cased the 8 bit is fine .. if you want to grade heavily then better off with an actual video camera is the first place.. re the A7,s Id rather have the FF sensor 8 bit that 10bit Micro ⅔ .. but it will happen Im sure.. as long as they don't over heat the whole time !

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