Panasonic Announces MPEG-4 Support in P2

editatjoes said:
Not sure if any of you have tried using H264 to encode media in Quicktime, but it is extremely slow going compared to many other codecs. It would be quite a feat if the HVX200 could encode realtime to H264, given how long it takes a dual processor G5. Not saying it's impossible, since I'm not an engineer, but I'm not getting my hopes up either.
Click to expand...
Oversimplifying:
Realtime interframe compression = bad quality
Slow encoding = good quality
 
Ahh, no!...That would be like recording a studio album in mp3 format as your master source...

H264 is still a lossy codec people, it is basically a glorified MP4 format, better than DivX format in between DivX and MPEG2 sizewise, but the quality is still lossy since you have a determinable bitrate, so sorry...I would much rather film 7 minutes of highquality than 30 or 60minutes or almost high quality

::: Connor
 
toke lahti said:
Oversimplifying:
Realtime interframe compression = bad quality
Slow encoding = good quality
Click to expand...

Ouch...the kind of says something about a G5 dual processor mac doesnt it?

Encoding on my AMD Dual Core PC is slightly over the 1:1 ratio. To encode a 10 minute length video file in Premiere Pro for H264 at 3000-8000 VBR takes about 10 minutes 15 seconds, or takes about 12 minutes for 2pass VBR, so I dont know what you are complaining about?

::: Connor
 
CORUSA Design said:
H264 is still a lossy codec people,
Click to expand...
? Every codec is lossy. MPEG-2 is lossy, HDCAM-SR is lossy, DVCPRO-HD is lossy, DV is lossy, DigiBeta is lossy, Wafian's Cineform codec is lossy, JPEG2000 is lossy, wavelet is lossy, HD-D5 is lossy. They all are.

The question is whether there's enough bandwidth allocated so that it's "visually" lossless. But unless it's something like a variant of LZW, there's going to be some loss in any video codec.
 
TSCC Techsmith is not lossy, Uncompressed AVI is not lossy, but apparently Mac's have problems with both of those formats. Glad I can work lossless on PC at least :)

::: Connor
 
toke lahti said:
Oversimplifying:
Realtime interframe compression = bad quality
Slow encoding = good quality
Click to expand...
Though of course realtime interframe compression CAN be high quality..... if you are a broadcaster and prepared to pay for the privilege.

By and large, quality, bitrate and complexity can be traded off one for the other, and a good system is one which strikes a good balance between them. Also, by and large, any overall improvement will come only by then throwing more money at the system, paying for either higher storage or more powerful processing. All too often blanket statements comparing inter- and intra- frame systems tend to compare them in terms of quality, which is meaningless without defining datarates and processing used. Like is not being compared with like.

What IS possible to say is that for intra- and inter- frame systems of comparable quality (say DVCProHD and MPEG2 at roughly 35-40 Mbs), the intra frame system will have a much higher bitrate, but be easier to edit, and require less effort to encode. For systems with the same bitrate, an interframe system will offer far higher quality, but be more complex (difficult to edit).

My understanding is that (like MPEG2, think Sony IMX) H264 can exist as I frame only, and this is what is proposed for P2 recording in the pro domain. Compared to MPEG2, many of the same arguments versus DVCProHD hold good. Same quality for lower bitrate, but more effort required to encode. Unlike with MPEG2, now in each case we are referring to an I frame only system.

I see it as maintaining the quality and ease of editing of DVCProHD, BUT at the expense of needing much more processing power, though with the benefit of lower data rate. With the improvements in computing power, and the biggest obstacle to P2 being cost of storage, it would seem a sensible way to go.

I would doubt it could be retrospectively applied to such as the HVX200, since I doubt the latter would be able to do the processing.
 
CORUSA Design said:
TSCC Techsmith is not lossy, Uncompressed AVI is not lossy, but apparently Mac's have problems with both of those formats. Glad I can work lossless on PC at least :)

::: Connor
Click to expand...

not really. I edit avi stuff all the time on FCP.
So you have to render...so what? Thats not an issue
with short form stuff (which 95% of mixed media is)
 
Doesn´t an even higher compressing codec than HDVs mpeg automatically lead to at least the same problems in post?
Like for CC?
 
Spartacus said:
Doesn´t an even higher compressing codec than HDVs mpeg automatically lead to at least the same problems in post?
Like for CC?
Click to expand...
Not necessarily, it's not just how much the signal is compressed, but HOW. A lower datarate may give better results with a more efficient codec, but I'd expect it come at the expense of more processing power needed.

Problems doing more than a limited amount of CC are more likely to be caused by 8 bit codecs, and I'm afraid here DVCProHD is likely to be no better than HDV. 8 bit is fine as a final recording/viewing quantisation, with enough leeway for steps not to be visible. But try manipulation (like CC) which effectively amplifies the steps, and that's when problems may occur which wouldn't with 10 bits. Hopefully this implementation of H264 will be 10 bit.
 
Spartacus said:
Doesn´t an even higher compressing codec than HDVs mpeg automatically lead to at least the same problems in post?
Like for CC?
Click to expand...
No, because the issues with HDV are sidestepped by avoiding the long-GOP structure. H.264 is a more efficient codec already, and then they're using a higher bandwidth to allow intraframe recording.

It's a year away anyway, so we'll see what happens when it comes out.
 
I hope the HVX200 processor is fast ennuf, but if it not, they could build a P2 card that does the h264 compression and send that output to the second P2 card. At 10mbits/sec of h264, that give you nearly 1 hours on 4gig. So I wouldn't too much mind loosing a card slot.
 
They wouldn't do anything like that though. Their h.264 implementation will be i-frame-only, so there's no way it'd be a 10mbit stream, I'm sure it'd be at least 50 megabits.

But there's basically no chance the HVX could encode h264 on the fly with the current hardware, and there's no chance they'd modify the card to do the encoding.

H.264 will be something reserved for future products, not the HVX.
 
penfever said:
mpeg-4 support -
this sounds like a HVX-200a feature to me...
Click to expand...

It is possible that that could be a NAB 2007 intro...

BUT we'll have to wait a year to see... :crybaby:

Worse yet, even after 1 year, we'll need to wait a while after that to see how the blind tests between 100 Mbs DVCPRO-HD and 50 Mbs MPEG-4, to see if there si any real difference.


Bob Diaz
 
BobDiaz said:
..........we'll need to wait a while after that to see how the blind tests between 100 Mbs DVCPRO-HD and 50 Mbs MPEG-4, to see if there si any real difference.
Click to expand...
I assume you're talking about picture quality. I suspect any differences will be slight, and one codec better in some areas, the other in others.

But in terms of real differences, the fact that the data rate is HALVED - for comparable quality - should be considered very significant in practical terms, and as regards making such as P2 universally viable. It means that a (much cheaper) 4GB card will have the same running time at comparable quality to a 8GB card now with DVCProHD.

It may also mean that Compact Flash becomes a more appropiate choice for 1/3" cameras than P2. With the reduced data rates that H264 would enable, CF would give more than adequate performance, at much less cost than P2, and with size/weight benefits in addition.
 
Well, back in December 2002, I started shooting video to Compact Flash using my Fuji Finepix 602 digital camera. The image was 640x480 @30FPS into an AVI file and 128MB gave me less than 2 minutes of video (with audio), but it was and is fun to play with...

The quality is NOT great, but it was only a matter of time that larger flash cards would make longer recording times and better quality possible.

I expect it's only a matter of time before we see a lot more cameras provide memory card recording.


Bob Diaz
 
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