AVCHD vs HDV

AVCHD is H.264, isn't it? If so, that's going to put an even larger load on the CPU for editing than HDV does. My P4-3.06 can barely handle two HDV streams for realtime effects.

Also, can any current editing programs actually edit the stuff?

If you look here:
http://ex-blog.panasonic.co.jp/exhibition/en/2006/10/ceatec_video_digest.html
you will see a video commentary (with an English translation) which describes the Panasonic range displayed at the recent CEATEC exhibition. This includes pictures of the forthcoming Panasonic AVCHD camera which captures to SD cards - it is about 2mins 40secs into the clip which covers the whole range of Panasonic products displayed.

Like you I do this as a hobby. If I do upgrade from DV to HD (still a big if because of the cost) it would be with a camera like this to replace my GS400. Canopus are now listed as supporters of the format so you, and I, would continue to be able to edit with Edius - presumably via the HQ codec.

Another, more useful, link about this new camera. The rep says it is due out by the end of the year.
http://gizmologia.com/2006/10/ceatec-2006-video-de-la-camara-avchd-de-panasonic

It seems to me to be too early to compare codecs. Don`t we need some production samples first?

So, I have some calls into Sony to help me understand how these two codec's differ. I have read that there is some good futures in AVCHD yet HDV is better today- I do not know. One thing I need to know is that with AVCHD, that either gets onto a DVD directly or onto a camera located hard drive. I am assuming that you cannot simply move that data onto my PC hard drive and start to edit, that you have to play back the data to run thru the codec and then capture the video/audio; is that correct?

That probably sums it up pretty well. I can well believe AVCHD is inherently more efficient, and that is equally likely to mean it will require more power to deal with it. Hence HDV may well be the best choice for today.

I doubt that is necessarily true, any more so than HDV and MPEG2. Even so, don't some solutions transcode HDV to a less compressed form for editing, to lesser the load on the computer?

Correct.

For example, Edius can ingest and edit MPEG footage, no problem except the time it takes to decode each 12-frame GoP for display or processing. So you have the option of transcoding it into an I-frame coding (such as Canopus HQ, or a lossless version) for editing. It takes more disk space (about 4 times more), but storage is very cheap these days.

More precisely, to move the load from the CPU to the hard disk :). Which is probably a bad idea with dual-core and better CPUs out now or in the near future... CPUs generally seem to improve faster than disks.

Great inputs from all. Upon further investigation I spens some time looking around the Siny web site and found this with paper on HDV, "Development of high-performance HDV™
devices based on the HDV 1080i specification for acquisition and production applications" which answered quite a few questions that I posed here. Based on the white paper, HDV is an MPEG 2 stream, and a GOP of 15. Of course that is recorded to a miniDV tape so you have to play that back to get it on your editing station.

The other Sony HD camcorders (consumer) that use the AVCHD codec also are MPEG2 data formats. What I remail concerned about is that these use a AVCHD codec to build the MPEG2 stream and I am assuming that when recorded video is played back on that camera the video is run back through the AVCHD codec to expand the data. If that is true, then simply moving the data from the camera to your hard drive, directly or indirectly, does not allow the AVCHD codec to decode the stream and thus you edit the encoded data.

Now, I may be completely wrong about here the codec gets involved; that is what I am trying to learn. I have a conference call set up with a Sony DV expert later this week to get some of these questions answered. Of course, all these questions are based on the need to know in order to select the right camera. My TRV-900 lasted 8 years and I hope to make an informed choice so my next investment lasts as long!

Again, the FX1, and thus the FX7 are too big for my applications. So, I am looking at Sony, Panasonic, JVC, Canon, . . . to find the either the best prosumer DV or HD camera wheresize makes sense; camera cost is a second order effect.

HDV GoP is 15 for the NTSC variants, 12 for the "PAL" variants. A half second of video.

Obviously, you have to use the correct decoder to decode, whether it be HDV or AVCHD. And it doesn't matter whether the footage is on tape or hard-drive.

Cineform's Aspect HD will transcode HDV to their intermediate codec for editing in Adobe Premiere Pro 1.5/2.0. Its very kind to old PCs like my 3.2GHz P4 (Core Mono ?!), which will play back 3 HDV streams with no problems. Cineform are now claiming here ...

http://www.dvinfo.net/conf/showthread.php?t=78027

that the latest versions of Aspect HD and Connect HD (for Sony Vegas) will also transcode AVCHD in the same way, allowing it to be edited in PremPro too. This is all untested as yet, but Cineform are very good at what they do, and if they say it can be done then you had better believe them.

I'm looking for a companion for my Sony FX1, and I've been looking at their CMOS chipped HDV cameras, but the idea of an HDD camera that avoids having to capture and whose output can be edited alongside HDV is very tempting.

Tony

No, not true. AVCHD is a codec in it's own right, exactly as is MPEG2. An AVCHD camera compresses to the AVCHD spec, MPEG2 is nowhere in sight. (AVCHD is a variant of AVC (or H264), with certain parameters defined.)

Perhaps simplistically, but let's say AVCHD and MPEG2 do the same job, with a given quality being achieved with a lower bitrate in the case of AVCHD. Unfortunately, you never get anything for nothing, and so too here. In this case, coding AVC is more complex than MPEG2 and requires more processing power.

You might also find that you have access to some of the best DV/HD experts in the world right on this forum.
Sharyn

Indeed, AVCHD, being a variant of H.264 is MPEG4 not MPGE2. And that means it can deliver the same image quality using about 70% of the bit-rate of MPEG2, assuming that it uses all the processing tools in the H.264 tool-set. The price is in the coding/decoding, MPEG4 takes far more grunt than MPEG2 does.

so here's something I think I already know, but you know, ask a stupid question...

I have premiere pro, 7.0, so basically not 1.5 or 2.0. I imagine that I won't be able to edit HDV in premiere, unless I upgrade to 2.0? There seem to be no patches/updates for older versions of premiere to give them HDV compatibility. This is lamesauce, because I am already in the boat of needing a new camera (dropped and broke my vx700 recently, and figure I should upgrade), but after purchasing that I won't even have the $200 or more to upgrade my software. Any thoughts on this? I'm guessing I'm going to be better off just going with a miniDV cam still...

Well - you can still get an HDV camera and just set it to record in standard DV mode until you upgrade your computer. Or maybe better, record in HDV and downconvert on capture - then the original tapes are in HD if you want to revisit them in the future. HDV models are also inherently widescreen, and with the vast majority of TVs now sold being 16:9, that must be seen as a factor, even if you remain in SD.

The situation's not quite so clear in the US. Although it's where there's most HD broadcasting, the penetration of real HD displays and receivers is still pretty low, so there's not quite the same impetus behind HDV as we've got in the UK (and that still surprises me a lot, considering there's no free OTA HD in the UK) because HD-ready displays are now outselling SD.

gotcha. that does sound like a plan... would I be able to capture in premiere (not version 1.5 or 2.0, I won't have the $200 to upgrade that for a few), or do these cams come with software for capturing that I could then use that footage in premiere?

thanks for the input... this is a dizzying situation for me.

All the HDV camcorders will record either in HDV (that's 1080 or 720 line formats) or in SD to DV/DVCAM. That measn they can downconvert the HD camera for recording to SD tape. They can also use that same downconverter to generate SD from an HD recording, so you can decide whether you want an SD tape that'll just work as any othyer would, or an HDV tape that you can use as SD by downconverting in ingest to the editor aznd hold onto for ,possible future editing in HD. It's your choice.

Leaving High Definition out of it for the moment, shooting widescreen is generally a good way to go at the moment, as 4:3 material derived from 16:9 by cropping is generally better than 16:9 derived from 4:3. (The line structure, interlace, etc is irrelevant in the former case, so no rescaling, only simple cropping.) If the material is ultimately intended for DVD that's especially true - make a widescreen DVD and the player will automatically crop or letterbox if you set it up with 4:3 in the output menu, and use a 4:3 TV.

You do of course have to make an allowance when filming - don't have anything vital at the edge of the screen. Most UK TV for broadcast has been shot like this for a long time now - shot 16:9, for digital broadcast, but allowance made for it being cropped for the existing analogue networks.

AVCHD is mpeg4 AVC H.264 codec: Doesn't it not have an mpeg2 transport stream header? (not codec , mind)

wow, this thread got pretty technical pretty quick :)

I have a more general question: I decided to go HDV ( I like tape, it's good for amateur use i.e. me...) and have just replaced my old PC100e with a HC7e. Purchase decision was based on a lot of external factors the most pressing being I had to have the camera in the next couple of weeks, which did narrow the field quite quickly.

oops, got to go, my camera is arriving now!

cool, it's arrived, very nice. But I wish it had the multi-function ring like the HC1 I looked at in the shop yesterday...the HC7 is MUCH smaller though.

anyway my question is, would it be better to shot in 720p or 1080i? is the p better than the higher res?

Surely, it's a Sony - and only 1080i is available?

I think you're right, as I can't find a setting for it! not a big problem though, best make sure any TV's I get are 1080...

I'm curious...

What exactly was the point of the AVC HD format?

Yes it uses MPEG4, which is more efficient (but that depends if you implement the advanced parts of MPEG4). However, it is intraframe instead of interframe, which reduces its efficiency.

The only benefit of intraframe compression is that it's easier to edit. However, with AVC HD being a new format, it will be more difficult to edit initially. Whereas most NLE vendors now have realtime MPEG2/HDV editing. So as far as I see it, AVC HD was a pretty pointless format???

b- Perhaps its only saving grace is that it supports higher bitrates and 4:2:2, so theoretically you can get better quality. For consumer applications, I think that this is unnecessary. For professional applications, I think I would prefer some sort of (intraframe) wavelet-based compression (especially Cineform, or perhaps Redcode).

Wavelet compression tends to remove noise, which is good when you need to pull keys or perform secondary color correction. If you aren't doing those things, then MPEG2 is fine to begin with. I mention Cineform specifically, since it would be nice if the industry could standardize on a smaller # of formats. Cineform is here now, and it works and is supported.

2- There are too many formats in the world IMO. This is another unnecessary format.

3- Perhaps I could be wrong...?

Glenn, there are two variants of the AVCHD - a consumer long gop version and a "pro" I frame version. I guess you're getting them mixed up?

Cineframe is not I frame only BTW.

Yes, wavelets tend to look better than block based codecs as they degrade. Much nicer to have a touch of softness than a nasty macroblock or mosquito type noise.

Graeme

That's the point, we criticise codecs not when they work (they all work well when they work well) but when they fail due to over-complex input. In those conditions, all variants of MPEG make horrid pictures with clearly visible blocking, but wavelets just make softer pictures which are far less worrying.

Ah ok, I wasn't aware that there were two versions.

I'll go eat some of my own words now...

Hi, I know its been some time since ayone has replied to this thread, but I would like some advice on whether I should go for a AVCHD or HDV camera.
I am an amateur, who video,s the family etc, but would like to progress to more serious stuff, with the right equipment.
Now as far as I know HDV records in MPEG2 whilst AVCHD is MPEG4. Both are lossy, and I think that MPEG4 is more lossy. Am I correct?

So I think the best option for quality should be the HDV format.

Also if the camera's processor is having to work harder for the AVCHD codec, then are we at the stage where rapid movements will overpower the codec, and result in blockiness?

Thanks,
John.:confused:

Editing is certainly an issue in considering your choice even tho both codecs are heavily compressed. Also bear in mind that HDV is a tape based format whereas AVCHD is recorded to solid state cards. This greatly simplifies capture to a pc but raises other issues about long term storage because you will want to reuse your SD card. The current crop of AVCHD cameras has not yet reached the full potential of the codec - the best are now at about 17Mbps whereas the format spec supports up to 25Mbps.

Like you I do this as an amateur so I have one chance to get it right. My choice, right now, is to stick with DV and wait until AVCHD cameras reach their full potential; at which time there may well be a better range of cameras on offer.

Editing is only an issue until the computers and software catch up which shouldn't be too long now -- long-GOP MPEG2 editing is standard now and well within the reaches of the average computer. The same should be true for AVCHD and the top end machines available now, which will be tomorrow's low end :)

SD cards are dropping in price rapidly and so can easily be considered their own storage medium and there are plenty of alternative storage mediums you could use to put footage on too. Bluray writeables are rapidly dropping in price (I think they currently cost about £2 each in the shops) and should hold about two hours of footage (and be replayable on your TV via a PS3!)

Steven

In broad-brush terms, MPEG4 produces the same image quality as MPEG2 at 3/4 the bit-rate. They are bot GoP-based coding systems, taking a group of frames (typically half a second) and coding them as a group. So, any uncorrectable error in half a second can cause a problem that lasts half a second. So, you need the storage medium to be rather more robust than for DV recording.

Most HDV camcorders are quite capable DV camcorders as well.

Although HDV is the "lowest level" of hi def for any serious recording , it is reasonable well implemented .
The Sony series A1, FX7, V 1, Z1, (even the enthusiast FX1) as well as Canon series XH A1 XHG1 and XLH1 are examples of well made HDV camcorders all of which use this same compressed format but are quite respectable AFAIK

AVCHD as implemented in consumer camcorders is really a consumer format to get Hi def to the masses in an easy to transfer "tapeless" medium.
I recently trialled Canons HG10 (which is one of the formats better examples). It has enormous fun value and in good light , with very careful panning impressive output on an HDTV but I think the AVCHD format is its achilles heel for any serious work

And that's why the higher level camcorders are using AVC-I, intra-frame only.

Interesting , I have the FX1 and HC1 but didnt think the FX 1 recorded diferently, just better because of superior optics and 3CCD
I would assume then that the DVCAM-HD is even better.
Unless you refer to XDCAM and HDCAM /SR ect
Does anyone know if the A1 is significantly different from the HC1 apart from the obvious physical differences 9 microphone ect?

The current A1 is indeed the discontinued HC1, and they both ran alongside one-another for some time. So the lens/chip assembly is identical.

Thanks

AVC-HD is more a collection of formats of differing data rates, and hardly surprisingly the quality varies with the rate. At the higher rates it should offer as good, if not better than HDV quality at a still lower bitrate - the downside being the additional computing needed to handle it. I haven't seen the camera you refer to, but suspect that (as with most cameras at this price) it's performance will be far more determined by the front end than the recording codec, at least if the higher data rates are used.

I wouldn't promote AVC-HD as a top end format - and neither do Panasonic, that's what AVC-I is intended for - but it should best be seen as comparable to HDV, and both a good match for 1/3" and lower type cameras.

AVCHD or HDV? It depends where you are starting from.

If you already have a DV camera and editing set-up, I'd say HDV is the best choice, since it is compatible with what you already have, in two important ways:
1) It will play your existing DV tape archive;
2) It will provide DV input to your existing editing system to cover any gap between upgrading the camera and upgrading the computer and software. You can either shoot DV with the camera or (as I would advise) shoot HDV and down-convert in camera when capturing to the editor.

If you are starting from scratch, I think HDV is still preferable, but it's not so clear cut. At the moment, HDV is easier to edit - it needs less CPU power to encode and decode, and it is supported by more software. These issues will become less important over time. Because it is recorded on tape in the camera, there is no need for an extra archiving stage. As the price of sold-state memory cards falls, this will also be less important. I'm not sure how far away we are from a 1-hour card costing £5. When we reach that point, tape becomes less attractive than memory cards.

I don't think there's much point having an AVCHD camera that records to DVD. However, hard-disc or BluRay cameras might be worth considering?