Will 1080/50p 28Mbps from Camcorder playable on computer without re-encode

[skydutch]

I used to have Sanyo VPC-HD1000 and record at the highest rate 1920*1080 (don't know bitrate).

I can directly copy file *.mp4 from SDHC card and playable without re-encode by using software like VLC or else...

Also I can Direct stream cut, without re-encode by using software Boilsoft (http://www.boilsoft.com/videosplitter/)



I wonder will 1080/50p 28Mbps playable and stream cut without re-encode by using above software ???

If not why should I buy 1080/50p 28Mbps's comcorder ???

Thanks in advance

[jagabo]

Playable? Yes, if your computer is fast enough.

[edDV]

,,,

If not why should I buy 1080/50p 28Mbps's comcorder ???

Thanks in advance

50p/60p will give you better better vertical resolution vs 50i/60i and is more convenient for computer display (no deinterlace required). All give 50/60 motion samples per second so are good for hand held.

Downside of 1920x1080 50p/60p @28 Mb/s is increased compression artifacts vs 1280x720 50p/60p or 1920x1080 50i/60i. @24 Mb/s.

Bottom line, you are trading off vertical resolution vs compression artifacts.

Now if you can do 50p/60p at better than 35 Mb/s the compression artifacts reduce.

[smitbret]

,,,

If not why should I buy 1080/50p 28Mbps's comcorder ???

Thanks in advance

50p/60p will give you better better vertical resolution vs 50i/60i and is more convenient for computer display (no deinterlace required). All give 50/60 motion samples per second so are good for hand held.

Downside of 1920x1080 50p/60p @28 Mb/s is increased compression artifacts vs 1280x720 50p/60p or 1920x1080 50i/60i. @24 Mb/s.

Bottom line, you are trading off vertical resolution vs compression artifacts.

Now if you can do 50p/60p at better than 35 Mb/s the compression artifacts reduce.

Basically, you're playing back a Blu-Ray. So if your PC can handle that, then you're good to go.

[jagabo]

No. 1080p50 is about double what Blu-ray is capable of.

[edDV]

,,,

If not why should I buy 1080/50p 28Mbps's comcorder ???

Thanks in advance

50p/60p will give you better better vertical resolution vs 50i/60i and is more convenient for computer display (no deinterlace required). All give 50/60 motion samples per second so are good for hand held.

Downside of 1920x1080 50p/60p @28 Mb/s is increased compression artifacts vs 1280x720 50p/60p or 1920x1080 50i/60i. @24 Mb/s.

Bottom line, you are trading off vertical resolution vs compression artifacts.

Now if you can do 50p/60p at better than 35 Mb/s the compression artifacts reduce.

Basically, you're playing back a Blu-Ray. So if your PC can handle that, then you're good to go.

No. 1920x1080 50p/60p is outside and above the Blu-Ray spec.

[2Bdecided]

Downside of 1920x1080 50p/60p @28 Mb/s is increased compression artifacts vs 1280x720 50p/60p or 1920x1080 50i/60i. @24 Mb/s.

Bottom line, you are trading off vertical resolution vs compression artifacts.

You keep saying that, but I've not seen one jot of evidence that it's true. I've seen evidence of the opposite!

By not having interlace, and not forcing the H.264/MPEG-4 AVC compression to cope with interlacing, the quality is dramatically higher at reasonable bitrates. 28Mbps is a reasonable bitrate!

The proof of the pudding...
http://tech.ebu.ch/Jahia/site/tech/cache/offonce/news/ebu-shows-end-to-end-1080p50-sig...l-chai-12sep11

Cheers,
David.

[smitbret]

,,,

If not why should I buy 1080/50p 28Mbps's comcorder ???

Thanks in advance

50p/60p will give you better better vertical resolution vs 50i/60i and is more convenient for computer display (no deinterlace required). All give 50/60 motion samples per second so are good for hand held.

Downside of 1920x1080 50p/60p @28 Mb/s is increased compression artifacts vs 1280x720 50p/60p or 1920x1080 50i/60i. @24 Mb/s.

Bottom line, you are trading off vertical resolution vs compression artifacts.

Now if you can do 50p/60p at better than 35 Mb/s the compression artifacts reduce.

Basically, you're playing back a Blu-Ray. So if your PC can handle that, then you're good to go.

No. 1920x1080 50p/60p is outside and above the Blu-Ray spec.

I wasn't speaking of whether or not it met BR specifications, I merely answered his question on how to determine whether or not his PC could handle his playback. Since it is an AVC encoded 1080p file stream with roughly the same bitrate as a BR, then his PC should be able to play it back if he it will playback a BR disc.

[jagabo]

I wasn't speaking of whether or not it met BR specifications, I merely answered his question on how to determine whether or not his PC could handle his playback. Since it is an AVC encoded 1080p file stream with roughly the same bitrate as a BR, then his PC should be able to play it back if he it will playback a BR disc.

No. It's twice as many frames per second and that will have a big impact on playback. Each frame must be decompressed and displayed in 1/50 of a second vs 1/25 of a second for Blu-ray. That will require twice as much CPU/GPU power.

[smitbret]

I wasn't speaking of whether or not it met BR specifications, I merely answered his question on how to determine whether or not his PC could handle his playback. Since it is an AVC encoded 1080p file stream with roughly the same bitrate as a BR, then his PC should be able to play it back if he it will playback a BR disc.

No. It's twice as many frames per second and that will have a big impact on playback. Each frame must be decompressed and displayed in 1/50 of a second vs 1/25 of a second for Blu-ray. That will require twice as much CPU/GPU power.

That's why the bitrate is a factor. Since it is measures in seconds and not frames it should be similar to any other 25mbps video stream.

[jagabo]

Bitrate is a much smaller factor than frame rate in terms of CPU/GPU requirement.

[smitbret]

Bitrate is a much smaller factor than frame rate.

Please explain, because if that's the case, then why don't we just reencode BR rips to 48fps and reduce the overall bitrate to save space?

[edDV]

Downside of 1920x1080 50p/60p @28 Mb/s is increased compression artifacts vs 1280x720 50p/60p or 1920x1080 50i/60i. @24 Mb/s.

Bottom line, you are trading off vertical resolution vs compression artifacts.

You keep saying that, but I've not seen one jot of evidence that it's true. I've seen evidence of the opposite!

By not having interlace, and not forcing the H.264/MPEG-4 AVC compression to cope with interlacing, the quality is dramatically higher at reasonable bitrates. 28Mbps is a reasonable bitrate!

The proof of the pudding...
http://tech.ebu.ch/Jahia/site/tech/cache/offonce/news/ebu-shows-end-to-end-1080p50-sig...l-chai-12sep11

Cheers,
David.

Per that document, the transmission chain was an uncompressed 1920x1080 50p GV LDK-8000 camera up linked at 38.5 Mb/s to the demo in tandem with with a 1920x1080 50i encode.

My point was 28 Mb/s 1920x1080 50p/60p is on the low side for an acquisition format because it needs to be re-encoded at least once to an edit master or to a distribution format. 50p has twice the pixels to process vs 50i. In fact, one could consider 1920x1080 50i to be 1920x540 50p the way it is handled in Blu-Ray players and advanced HDTV sets, hence the vertical resolution issue.

I will grant you that 50p has 83% frame rate vs. 59.94p so it could be claimed it only requires 83% the bit rate. So 28.Mb/s @50p would be equivalent to 34 Mb/s @59.94 and may be adequate for a single re-encode.

A parallel issue is AVC codec efficiency advances over time and when the new codecs reach consumer hardware chips.

High end hardware broadcast encoders can perform at much higher compression than consumer camcorders and will improve over time. A key advantage for broadcast compression is uncompressed/low compressed acquisition and editing pre-encode.

720 50p www.itea2.org/project/result/download/result/5590

[edDV]

Alternate link
http://docs.google.com/viewer?a=v&q=cache:3OMZp385RZcJ:www.itea2.org/project/result/do...6NRkCP3Lci3KVg

[_Al_]

edDV - but there is final step you are not mentioning and this is final viewing, interlace footage needs to be deinterlaced, this is problem for PC realm and with cheaper TV's .... so at the end you can get some serious artifacts you are not calculating with ...

[edDV]

edDV - but there is final step you are not mentioning and this is final viewing, interlace footage needs to be deinterlaced, this is problem for PC realm and with cheaper TV's .... so at the end you can get some serious artifacts you are not calculating with ...

I agree PC software deinterlacers (e.g. Yadif) are still crude but recent HD display cards are doing better.

Blu-Ray players outputting 1080i as 50p/60p over HDMI and most 50/100 Hz and 60/120Hz HDTV sets simply separate and re-size fields for a perfect deinterlace to 50/60/100/120 progressive.

[jagabo]

Bitrate is a much smaller factor than frame rate.

Please explain, because if that's the case, then why don't we just reencode BR rips to 48fps and reduce the overall bitrate to save space?

I'm saying in terms of CPU usage doubling the bitrate has less of an effect than doubling the frame rate. Here's the CPU usage while playing same 60p source video encoded at 60 fps and decimated to 30 fps, both encoded at 30,000 kbps (CoreAVC with software decoding on a Core i5 2500K). The first half of the graph is the 30 fps playback, the second half the 60 fps playback:



The 60 fps playback obviously requires much more CPU power. Try it yourself if you don't believe me.

[2Bdecided]

most 50/100 Hz and 60/120Hz HDTV sets simply separate and re-size fields for a perfect deinterlace to 50/60/100/120 progressive.

That's hardly perfect!

[2Bdecided]

My point was 28 Mb/s 1920x1080 50p/60p is on the low side for an acquisition format because it needs to be re-encoded at least once to an edit master or to a distribution format.

If you have high standards, 1080i50 @ 24Mbps and 1080p50 @ 28Mbps are both junk for acquisition and subsequent re-encoding. If you have low standards, they're both wonderful.

In practice, 1080p50 @ 28Mbps is better. This isn't the Emporer's New Clothes - the latter format will win, not because people are being duped, but because it's better.

In fact, one could consider 1920x1080 50i to be 1920x540 50p

Not when talking about MPEG encoding. In a real 1920x540p50 source, if nothing moves, nothing changes. Whereas if you're talking about 1080i split to 540p, even if nothing moves, the entire 540p frame could change each and every time - certainly any details bits of it will be different from "frame" to "frame" because the frames are offset. That's quite a difference from a coding perspective: no change versus all change. Helps to explain why 1980x1080p50 works so well in comparison.


Of course, most consumers don't edit or re-encode. So...
"Perhaps surprising at first, initial tests at the EBU have shown that 1080p/50 will not require more bitrate than
1080i/25 for broadcasts, but naturally it will show better picture quality on large displays."
from http://tech.ebu.ch/docs/events/ibc11-ebutechnical/presentations/ibc11_10things_1080p50.pdf

It suggests bitrates for acquisition that are far higher than we're discussing here. As I said, some people will think either of the formats we're discussing is junk for acquisition. Though they agree with you that 50p will need more than 50i in the context of re-encoding - though they're talking about chains of multiple re-encoding cycles - something normal consumers never do (unless they're both stupid, and have too much time on their hands!).

Cheers,
David.

[edDV]

My point was 28 Mb/s 1920x1080 50p/60p is on the low side for an acquisition format because it needs to be re-encoded at least once to an edit master or to a distribution format.

If you have high standards, 1080i50 @ 24Mbps and 1080p50 @ 28Mbps are both junk for acquisition and subsequent re-encoding. If you have low standards, they're both wonderful.

In practice, 1080p50 @ 28Mbps is better. This isn't the Emporer's New Clothes - the latter format will win, not because people are being duped, but because it's better.

I agree 50/60p is a superior acquisition format to 50/60i. The point is whether 28 Mb/s is adequate especially for 60p given current h.264 codec performance. In time codec performance will improve but camcorder chip sets are not upgradable. You must buy a new camcorder.

Currently, editing AVCHD requires a re-encode unless one cuts on I frames with half second accuracy. There are no "smart render" cutters yet for AVCHD. Even if there were, 1080 50/60p is not supported for Blu-Ray or "AVCHD" discs or players. One is forced to re-encode to 50/60i or downsize to 1280x720p.

One huge advantage 50/60p has today is a superior downsize to a 720x576 50i or 720x480 60i DVD in programs like Vegas.

[edDV]

In fact, one could consider 1920x1080 50i to be 1920x540 50p

Not when talking about MPEG encoding. In a real 1920x540p50 source, if nothing moves, nothing changes. Whereas if you're talking about 1080i split to 540p, even if nothing moves, the entire 540p frame could change each and every time - certainly any details bits of it will be different from "frame" to "frame" because the frames are offset. That's quite a difference from a coding perspective: no change versus all change. Helps to explain why 1980x1080p50 works so well in comparison.

Of course, most consumers don't edit or re-encode. So...
"Perhaps surprising at first, initial tests at the EBU have shown that 1080p/50 will not require more bitrate than
1080i/25 for broadcasts, but naturally it will show better picture quality on large displays."
from http://tech.ebu.ch/docs/events/ibc11-ebutechnical/presentations/ibc11_10things_1080p50.pdf

It suggests bitrates for acquisition that are far higher than we're discussing here. As I said, some people will think either of the formats we're discussing is junk for acquisition. Though they agree with you that 50p will need more than 50i in the context of re-encoding - though they're talking about chains of multiple re-encoding cycles - something normal consumers never do (unless they're both stupid, and have too much time on their hands!).

The current Blue-Ray players and HDTV sets take the one line field to field vertical offset into account, otherwise you would see vertical jitter on still scenes. The Sony players at least do a correct field by field step advance for 50/60i or frame by frame for 50/60p source. The interpolation quality even in high detail slow moving areas is surprisingly good.

The EBU broadcasters can manage 50p from camera to HDTV tuner with one encode and have high quality hardware deinterlacers to cope with legacy 50i source.

That work flow does not exist for the AVCHD prosumer producer except when playing the camera file direct to the display. Every other path requires at least one re-encode.

HDV/XDCAM and AVC-Intra users have smart render cutters but at 1080 50/60p still can't use Blu-Ray without a re-encode.

[jagabo]

Of course, most consumers don't edit or re-encode.

Yes. I think edDV is stuck in a broadcast/professional mentality were acquisition needs to be very high quality to survive several generations of reencoding. 50p or 60p h.264 at 28 MB/s is sufficient for most consumers who won't be reencoding, or just reencoding transitions and a few cut GOPs. It gives them a sharp picture with smooth motion with very few macroblock and posterization artifacts. In most cases that leaves them with better picture quality than they get from their bitrate starved cable and satellite TV reception.

[edDV]

Of course, most consumers don't edit or re-encode.

...won't be reencoding, or just reencoding transitions and a few cut GOPs.

Someday that will be true but not yet. Any frame accurate editing of AVCHD requires a recode (all GOPs).

[jagabo]

Of course, most consumers don't edit or re-encode.

...won't be reencoding, or just reencoding transitions and a few cut GOPs.

Someday that will be true but not yet. Any frame accurate editing of AVCHD requires a recode (all GOPs).

VideoRedo has frame accurate editing of h.264 and only reencodes cut GOPs. But it's true that most editors don't.

In any case, most consumers don't need frame accurate editing. They don't care if there's a half second of junk here and there, or if a half second of something gets cut off. In fact, most consumers don't do any editing. They just shoot and throw the tapes in the closet. Or save the files they want from the memory card.

[edDV]

That would be true for "most consumers" but a prosumer producer has no way to deliver a 1920x1080 product without a re-encode unless shot 50/60i or 25/24p for Blu-Ray or AVCHD disc delivery. 1280x720 50/60p is also an option.

Other re-encode workflows
1080 60p -> AVC 1080 60i Blu-Ray
1080 60p -> MPeg2 480 60i DVD
1080 60i -> MPeg2 480 60i DVD
1080 24p -> MPeg2 480 progressive DVD
1080 60p -> AVC 1080 30p for Youtube
1080 60i -> AVC 1080 30p for Youtube
1080 24p -> AVC 1080 24p for Youtube

and similar for 25/50 fps.

[jagabo]

a prosumer producer has no way to deliver a 1920x1080 product without a re-encode unless shot 50/60i or 25/24p for Blu-Ray or AVCHD disc delivery. 1280x720 50/60p is also an option.

Yes.

[_Al_]

I do not understand why is YouTube waiting to allow 50p, they can start with 720p50,60 only for example, why not ?
They can drastically change this stalling game of broadcasters and BD specs creators (perhaps both are the same thing ) .

BD specs were changed anyway, it is not a strict norm like DVD video was. The more they postpone to allow their fw to play back 50p, 60p within BD structure, the sooner it will be death of BD for consumers later ... alternatives will pick up ...

[2Bdecided]

The simple point is, with fewer bits per original pixel, some would think that 1080p50 would look worse than 1080i50 at the same 20-something Mbps (i.e. show more artefacts), but in fact it looks better.

Something is going to come along to deliver this straight to ordinary consumers (I mean without actually hooking the original camcorder up). It always does.

Can't you just put it on a USB stick and plug it straight into a compatible TV already?
1080p50 is inevitable on BluRay - 3D/MVC is already doing effectively that (1080p48), but for a different purpose.

Next generation silicon is going to do 1080p60 for each eye (i.e. effectively 1080p120). That'll be fun.

Cheers,
David.

[edDV]

Most HDTV sets will take 1080 50/60p but want linear ts (mts, m2t) or mpg containers. Maybe newer ones like m2ts.

Blu-Ray players like linear ts and random access m2ts but may not play 1080 50/60p.

...
Can't you just put it on a USB stick and plug it straight into a compatible TV already?
1080p50 is inevitable on BluRay - 3D/MVC is already doing effectively that (1080p48), but for a different purpose.
...

That USB stick would need to be class 4-6 for 28 Mb/s

[deadrats]

Please explain, because if that's the case, then why don't we just reencode BR rips to 48fps and reduce the overall bitrate to save space?

in a way you are somewhat correct, but in a more accurate way you are taking an over simplified view of things.

yes, bit rate is the amount of data per given time unit (usually measured in seconds) of a particular stream; 25 mb/s literally means 25 million bits per second but how those bits are arranged also plays a factor in how much work a cpu and/or gpu has to do: if the video stream is all I frames, then the workload is reduced, if you also have P(redictive) frames then you have an additional workload, if you have B(i-directional) frames that increases the workload and reference frames increases the workload further still.

if you have 50 progressive frames per second you now have double the number of calculations that have to be done in the same unit of time versus 25 progressive frames per second; the data rate of 25 million bits per second implies that each individual frame of the 50p video will be of lower quality versus the 25p video but it also clearly implies that the amount of work needed to decode the 50p file is also greater.

in a nutshell it's idiotic beyond belief to use double the frame rate without also doubling the bit rate and it's also naive not to expect double the frame rate to require theoretically double computational power.