combatentropy
Veteran
I predict 2016 will be the Year of the Firmware Updates.
New Sony FS E-mount 4K camcorder to be announced at IBC
- Thread starter Rishaar
- Start date
I predict 2016 will be the Year of the Firmware Updates.
andykwilkinson
Well-known member
Yes, but knowing Canon, I think they would announce that a firmware update is coming (for some kind of limited QFHD upgrade for the C100 MkII) towards the end of 2016 for release in Spring 2017. Ha!
By then I will have lost interest as my FS5 (that I ordered immediately on it's launch day) will be my main tool - and my much loved original C100 (which would never get any firmware upgrade now) will be relegated to C cam - its worth more to me to keep it than sell it now.
Mind you, if the FS5 is as laggy and buggy as the FS7, then I might be wishing for a Sony firmware update ASAP - although initial reports suggest the FS5 is very menu responsive. Time will tell regarding bugs.
By then I will have lost interest as my FS5 (that I ordered immediately on it's launch day) will be my main tool - and my much loved original C100 (which would never get any firmware upgrade now) will be relegated to C cam - its worth more to me to keep it than sell it now.
Mind you, if the FS5 is as laggy and buggy as the FS7, then I might be wishing for a Sony firmware update ASAP - although initial reports suggest the FS5 is very menu responsive. Time will tell regarding bugs.
Long-GOP shouldn't make any difference, and the workhorse broadcast camera in the UK at the moment is probably the PMW500 - XDCAM 422, and also long-GOP.
There seems to be a common misconception that in terms of quality "long-GOP means not as good", and that simply is not true. It's quite possible for a long-GOP codec to be more robust than an I-frame only codec, it'll depend on other factors, overall bitrate, and codec efficiency being maybe the most obvious. I suspect the misconception arose because in the past camera codecs did tend to be I-frame, long-GOP being used where low bitrate was important (streaming etc) - but as a rule of thumb a long-GOP codec will give equivalent quality to an I-frame codec at with something like a 2-3x bitrate saving.
There are occasions where an I-frame only codec is desirable - it means easier processing in an NLE, and is more appropriate for use in video servers. In which case it may be more convenient to originate in the native format, but such will likely be less convienient in terms of bitrate and file sizes in camera. Hence it's common to shoot in something like XDCAM422, and transcode for post.
I think the basic answer to your question is that the FS5 codec is fully acceptable in terms of quality for mainstream HD broadcast - the long-GOP aspect is here irrelevant - but may need transcoding for post etc for reasons of convenience.
andykwilkinson
Well-known member
Regarding the Sony FS5, the other factor to bear in mind is that it uses dual-pass encoding as outlined by the Senior Sony Manager at around 6 minutes 20 seconds in this video clip. This could be a MAJOR technological advantage for the quality of footage this cam is capable of encoding internally using it's particlar implementation of XALC-Long GoP - for the "relatively low" bit-rates it uses for 1080p (50Mbps) and QFHD (at 100Mbps) - and 4K in the future.
https://vimeo.com/138861804
He clearly states that this feature is unique to Sony - I'm not sure if it is unique to the FS5 or is used in other Sony cams though.
https://vimeo.com/138861804
He clearly states that this feature is unique to Sony - I'm not sure if it is unique to the FS5 or is used in other Sony cams though.
dmitrizigany
Veteran
In HD it's 10bit 4:2:2. In 4K its 8bit 4:2:0
Bern Caughey
Veteran
While discussing the FS7, Sony's Juan Martinez wrote, "Without going into a significant amount of detail, both XAVC Intra and Long use the dual pass encoding technology originally developed for BluRay encoding".
https://community.sony.com/t5/FS7/PXW-FS7-USER-MANUAL-for-DOWNLOAD/td-p/470195
Imagine the F5 & F55 use the same tech.
alex1
Well-known member
Thanks. Do you have a source?
andykwilkinson
Well-known member
Just watch the video I posted at #186 for this (and many other) technical details on the FS5.
Danilo Del Tufo
Well-known member
I've read about Sony FS5 that at 720p the variable framerates are continuos without burst mode, is true?
Here's all the continuous frame rates on the FS5 according to Sony Pro UK:
[TABLE="class: table-type1, width: 906"]
[TR]
[TH]Recording Frame Rate[/TH]
[TD]XAVC QFHD (3840 x 2160) @29.97p, 25p, 23.98p 100Mbps/60Mbps
XAVC HD (1920 x 1080) @59.94p, 50p, 50Mbps/35Mbps
XAVC HD (1920 x 1080)@59.94i, 50i, 50Mbps/35Mbps/25Mbps
XAVC HD (1920 x 1080)@29.97p, 25p, 23.98p, 50Mbps/35Mbps
XAVC HD (1280 x 720)@59.94p, 50p, 50Mbps
AVCHD (1920 x 1080)@59.94p, 50p, PS mode(28Mbps)
AVCHD (1920 x 1080) @59.94i/50i/29.97p/25p/23.98p,
FX mode (24Mbps)
FH mode(17Mbps)
AVCHD (1280 x 720)@59.94p, 50p,
FX mode(24Mbps)
FH mode(17Mbps)
HQ mode(9Mbps)[/TD]
[/TR]
[/TABLE]
Danilo Del Tufo
Well-known member
Sorry for misunderstanding, I was referring to super slow motion mode (100-200 fps) as continuos in 720p
andy-
i apologize for my naiveté but can you give me a rough idea why this technology would benefit the footage from the fs5?
thanks in advance.
be well.
rob
smalltalk productions/nyc
i apologize for my naiveté but can you give me a rough idea why this technology would benefit the footage from the fs5?
thanks in advance.
be well.
rob
smalltalk productions/nyc
dmitrizigany
Veteran
It's been discussed a lot on this forum, poke around and you'll find sources too!
andykwilkinson
Well-known member
Simply put, double-pass encoding will result in better results for any given bit rate over single pass...that's why we all use it (or perhaps even better, multi-pass) when exporting, for example, from our NLE's for anything we care about. The fact that some Sony XAVC cameras can use this efficient way of encoding is interesting.
Now we know Sony are using it for the FS5, FS7 (and I would assume their higher end F series cams) I would love to know how far DOWN in their range this dual-pass XAVC encoding trick goes.
Does it happen in the Sony X70 for example - as a way of squeezing the very best results out of its paultry 60Mbps MXF wrapped XAVC codec?
Does my PMW-300 use dual-pass when I run it in XAVC mode - rather than in XDCAM 50Mbps 422?
And what about the AX100 with its consumer variant XAVC-S codec - at up to 100Mbps? Does this cam and XAVC-S also use dual-pass encoding?
I don't know the answers to these questions - only Sony techies will - but I do know that I am very happy to learn that the FS5 will have some technological edge to help it make the best use of its designated, and otherwise rather modest, encoding bit rates.
This subject really needs the input from some of you codec gurus.
Me no Andy.
But, in DVD's, dual-pass allows for a more efficient allocation of bandwidth/bit rate. It slows down when there's less need for it. It speeds up when there's a demand for it. Rough example - let's say the bit rate is 100 Mbps on average but it can slow down to 80 on some slow changing scenes and speed up to 120 on others. In a live recording mode, this is accomplished by increasing the buffer, so it's kind of/ sort off not quite live but it is more efficient. Naturally, for that, a camera needs more memory and processing power too.
(the search function doesn't always deliver instant results)
PS. That "real" Andy just posted too ... but I ain't deleting mine. And I ain't no guru.
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To add to the previous two comments, then in conventional 2-pass encoding the first pass "analyses" what is to be encoded, especially where there is a lot of movement, and where scenes are pretty static. It then allocates the available bitrate accordingly - more to the former, less to the latter. Hence the AVERAGE bitrate is very much lower than PEAK, yet the quality suffers little compared to if the whole file had been encoded at peak rate. Hence it makes far more efficient use of a given bitrate.
And it's yet another reason why simple bitrate comparisons between codecs are pretty meaningless, quite apart from differences between MPEG2 and H264 etc.
What Sony seem to be doing is taking things to another level. In HDV days, the bitrate allocation between I frames and difference frames was fixed. A big step forward was to make it dynamic - change the ratio according to scene content. So in a static scene a lot is allocated to I frames, in a scene with a lot of movement the difference frames get a far higher proportion.
Which is why XDCAM performed so much better than HDV - in spite of them both being MPEG2 and XDCAM EX not being that much higher bitrate than HDV.
This seems to be taking that principle to a higher level. As DLD says, in a (near) real time system like a camera encoder it can't get the efficiency of true two pass as used in encoding such as a DVD - but buffering could still gain a significant improvement, the bigger the buffer, the more it'll be.