Sony's HDRSR1 vs HC3

Quote:
I just picked one up from Fry's in Renton, WA last night. Too soon for much

real comment, but here's my opening .02 :


(1) Video quality HDMI to my Hi-Def (720p) home theater projector (AE900U) is pretty stunning. Not perfect, but WAY ahead of anything I've ever seen for $1500 .


(2a) The utilities supplied with the HDR-SR1, well, they work. Mostly. You can play native AVCHD files burned to special-format DVD's on computers, albeit a few caveats. Transcoding to WMV-HD or other capable formats isn't available yet that I can tell. I did send off emails to Sony (Vegas) and Nero asking when the format would be supported. No answers as yet.


(2b) The supplied utilities WILL transcode to standard DVD-format MPEG2 with the 5.1 AC3 audio track intact. That's a biggie for me, your mileage may vary. (Being a DSP audio engineer and surround junkie makes me less than objective on this one)


(2c) After transcode, the resultant MPEG file is... Well, it's "ok". Motion and other artifacts abound, as one would expect from a freebie MPEG encoder.


(3) I personally LOVE the touch screen and new ergonomic features. Other people don't.


MY BOTTOM LINE:

[dot] It takes KILLER video, but you may have to wait a few months before you can do any real editing.


[dot] It's MPEG4 (yay!) and the AVCHD format supports native multichannel audio, which HDV does NOT.


[dot] I have one, neener-neener.


--jim

Quote:
The "Picture Motion Browser" software that comes with the camera allows you to do VERY basic "trimming", yes. You can save clips (native format) and also save individual frames as JPEG files.


The camera mounts easily as a USB drive once the packet driver is installed with the software. The software optionally uses a "calendar" still image indexing scheme that looks like it might actually be a good idea for those that keep track of images on some kind of timeline.


I've been playing with the various recording "quality" (compression) settings and found there's a huge difference between the default 7mbps rate and the highest quality "XP" 15mbps rate. I'm going to do a few experiments over the next few days to see if I've given a bum steer on the MPEG2 transcode quality. I need to be sure I have a good feel for the difference between artifacts and noise in the MPEG4 compression versus additional junk introduced by the transcode. Obviously there's a loss there going down to DVD resolution, but I need to make sure I'm giving the transcode a fair shake. Very subjective stuff compressing and re-compressing with different codecs.


--jim

Jim,


can u upload a sample clip at 15Mbps? i'm wondering what's the pq compared with canon HV10 which seems to have good reputation on its PQ.


thx

BXZ



Quote:

Quote:
I can do that in the next day or so, but the only way to play the clips for now is with a player that can handle the AVCHD format. The codec is H.264, but Matsushita and Sony decided to make the carrier format just enough different that none of the common MPEG4 players/utilities will play it correctly. The only other thing I can think of would be for me to post an ISO DVD image that should play on a Blu-Ray player, assuming anyone has one of those. I say "should" because Sony says it works. I can't verify it here yet. Ideas, anyone?


WARNING: RAMBLE ALERT, THINKING OUT LOUD

One thing I haven't mentioned here so far is that any number of pundits have waxed lyrical about the potential of the AVCHD format "failing". Since only the file container format is different from other MPEG4 implementations, the very worst thing that *could* happen is that someone would need to write a quickie converter from AVCHD to some other MPEG4 format(s). It would be lossless, since there would be no transcoding required. The host player or NLE would need a multichannel AC3 decoder, but I at least don't believe that's a real problem considering the camera is a "pro-sumer" device. If a bottom-end player and NLE like Nero 7 can afford royalties for both AC3 decoder and encoder, then the rest of the crowd can too.


Again, though, all of this is speculation about an absolute worst case. There's no real reason why the format should fail. It's H.264 at a fair data rate and it supports multichannel audio. Those who are comparing it to MPEG2 at 15Mbps are either forgetting or ignoring the differences between the two codecs. Someone correct me if I'm wrong, but aren't network ATSC MPEG2 TS single streams 14Mbps? Leno ain't pretty at any resolution, but H.264 at 15Mbps should be at least potentially a lot better.


So... The sooner AVCHD support gets into everone's favorite NLE, transcode utility and codec/format stack the better everyone will feel. I can't say when that will be, but I suspect Vegas 7 at least will have it RSN.


My completely subjective, self-serving, rambling and unadjusted for inflation .02,

--jim

Quote:


Jim,


If you'd indulge a neophyte here...


I've been waiting for a HDD HD camera, and this one seems to be a great first-to-market effort by Sony.


Can you offer a simple layman's explanation of what AVCHD is? I'm concerned about compatability issues (such as Blu-Ray vs HDDVD)


Also:


1. are there compatability issues in saving to a PC HDD? In other words, if saved to a computer HDD, and then from there output to a PJ (Infocus 7210 in my case, @ 720p max resolution), would you retain the 1080i resolution? (I guess this presupposes your computer will output @ 1080i, perhaps another subject...)



2. Would I be correct in assuming the only way to convert to a DVD and retain the resolution would be to have an HDDVD burner? (I have an HDDVD player, & not interested in Blu-Ray)


Thanks... Alvin

Quote:
Alvin,

Good questions! Please bear in mind that I'm a signal-processing guy, not a specific expert on codecs and transport formats. With that in mind:


AVCHD stands for "Advanced Video Coding, High Definition". Internally, it uses AVC/H.264/MPEG4 (all the same thing) compression for the video. The multichannel audio stream is compressed and stored using Dolby Digital 5.1 (AC3). Sony and Matsushita (Panasonic) created a new, only slightly different file/transport format for this and decided to call it AVCHD. Very confusing thing to do, in my opinion. The format is only slightly different than other "mainstream" MPEG4 transport formats, and including the codec name as part of the transport stream name is, well, not something I would have done.


Your question #1:

Let's break compatibility down a bit -

(A) Using a Windows box to store/scale/convert/render 1080i AVCHD isn't trivial in the least. It requires pretty much the very latest CPU, RAM, disk and video card technologies to be able to keep up in realtime while still doing all the other things that a Windows box has to do internally. When I say "latest" I do in fact mean CPU's like Intel's dual-core (Conroe) or quad-core (Kentsfield) with FAST DDR2 memory and SATA-3 or SATA 3GB disks. Both ATI and NVIDIA have capable video chipsets now at the high end of their offerings. (note to AMD fanatics - they may have something that will work as well, I just don't know as much about them)


(B) You can either have the PC render the video and output to the native projector format, or use a pass-through if the projector has ability to convert formats internally. Experience shows that using the PC is normally a much higher quality solution, although the conversion yet again adds to the processing load.


(C) There currently aren't any straightforward AVC-compatible players for Windows Media Center, or really any very good ones for HTPC use at all. That will change, but in the meantime one possible (if technically complicated) solution might be to use Elecard's MPEG decoder and H.264 plug-in with someone else's player.


Your question #2:

AVCHD is most directly compatible with Blu-Ray, sorry. Sony packages a utility with the camera that will burn AVCHD directly to standard DVD-format disks that can be played (they claim) in any Blu-Ray player. Using standard DVD media will limit runtime to around 20 minutes for single-layer disks at the highest quality 15Mbps setting. I don't know yet if the utility supports dual-layer DVD media. If so, you can double that to roughly 40 minutes.


Converting to HDDVD may become possible in the future, but it'll be tricky business. Here's why:

(A) HDDVD uses the VC-1 compression "standard". The spec claims compatibility with AVC, but you may run into undiscovered country.

(B) A transcode from AVC to HDDVD-native VC-1 would be the most compatible, but there would be losses since AVC and VC-1 are only cousins, not directly compatible.


DISCLAIMER:

These are the facts as I currently know 'em. If anyone has solid info please feel free to correct me.


--jim

Quote:
Thanks very much, Jim...


Since I don't have the latest/greatest processor such as a dual-core (I ALMOST bought one with my 6-8 month ago Lenovo notebook, but I didn't think I'd ever be doing anything that required that much processing power... oh, well...) then it sounds like I'd need to stick with some other type of data saving device.


If a transcode from AVC to VC-1 might be problematic or lossey, then trying to save to DVD (HDDVD) seems inadvisable also.


Which, ultimately & unfortunately, might mean the Sony is not for me.


Dang Sony --- great, leading edge stuff, but not compatible with the rest of the world (which I guess is their intent).


Two other questions: If I wanted to gamble that a lossless VC-1 transcode might be possible some time in the future (unless everyone thinks this is highly unlikely), could I save the camcorder data to a portable hard drive without data loss? Then, I'd just be limited to standard def playback until that day arrived, but all my video would be recorded & stored in HD.


I'm not at all in touch with the rumor mill about any other manufacturer plans for Hi Def HDD camcorders. Do you (or other forum members) have insights in that regard? (Other than the Canon, which stores on mini-DV)

Quote:
Alvin,


I only have a few additonal comments, then I'll quit hoggin' the floor and let someone else express an opinion...


(1) Sure, you can store as much vidoe as you want on portable drives without loss, assuming you can back it up as data to some other media. (hard disk crash would otherwise wipe you out) It's when you convert formats that the losses occur.


(2) A completely lossless AVC to VC-1 transcode can't happen, because the

DCT compression schemes aren't directly compatible. At the risk of being flamed into eternal hell, I'll also point out that MPEG4 was a standard long before April of this year. OTOH, *assuming* one can trust the HDDVD spec sheet and that manufacturers implement the entire spec, it *should* be possible in the future to create a HDDVD-format disk using AVC compression and have it play on a HDDVD player without loss. That will require a conversion (not lossy transcoding) utility, tho.


(3) No specific knowledge of other HD hard disk camera offerings, although I have heard a -rumor- that Panasonic is working on one that will use AVCHD.


My .02, going back to work now on deliverables for Monday. (groan...)

--jim

AVCHD is *not* a proprietary format. Its really a set of specifications (which is why AVC is in the name) based on open standards. It itself is also an open standard-- so anybody can make software that works with it, provided they have licenses to the standard codecs it supports (H.264 and AC3)


I'm not sure why they went with a different transport format, but I am pretty sure that it was chosen due to technical requirements of DVD writers or flash memory-- as these two forms of storage impose constraints on datatreams, and also, it is a big thing to do real time H.264 encoding in hardware in a camcorder...at any rate, the quicktime file format (Which the MPEG-4 file format is based on) is not necessarily well suited to writing out in real time when you don't know how long the movie is going to be, etc.


AVCHD is based on the AVC profile (a profile of MPEG-4, the standard) which specifies H.264 (the codec) and stores in a new AVCHD transport stream format. So, MPEG-4 is both a specficiation and a file format (but not a codec or compression scheme, though people often say MPEG-4 when they mean H.264... but you can have an MPEG-4 file with MPEG-1 video, and this would be a quicktime mov file since the MPEG4 file format is based on quicktime)



So, Sony and Panasonic went as far towards embracing open standards as I believe was technically possible in these products, and it should be no time before lossless converters exist to move the transport stream files into proper MPEG-4 formated files.

Quote:
Ok... Doesn't seem to be inconsistent with what we've been discussing. ?

The "lossy" conversions we're talking about are to VC-1. (ala HDDVD)

--jim

Quote:
No way to know for sure without a lot more info. The HDDVD spec supports MPEG2 *also*, so if the export from HDV to HDDVD is done in the software in MPEG2 a lossless transfer to theoretically possible. If the program is transcoding the HDV MPEG2 stream to VC-1, then the conversion is definitely lossy.


Same thing applies to the Sony camera. Again in theory, HDDVD supports AVCHD/MPEG4/H.264 . If a utility existed to build a HDDVD-format disk using the Sony-native AVCHD stream, a lossless transfer could again be accomplished.


Unfortunately, this is all speculation until software is created to do all the above. Whether the manufacturers implement the standards completely and correctly is anyone's guess until these things are actually tried.


So to specifically answer your question: It's theoretically possible, but software does not currently exist, nor have the 1st-generation players been tested in this manner that I know of.


--jim

I purchased the HDR-HC3 from Amazon on 10/12/06, so I have about ten days left in my return period. I needed the camcorder right away to flim some college stuff, so I could not wait for the HDR-SR1.


I am familiar with the comparison, such as SR1 supports Dolby Digital 5.1, SR1 has a hard drive of course, SR1 has a removable microphone input. In fact, Amazon is throwing in a blue tooth mic if you buy the SR1. You can currently edit HDV using Premiere (at least, I think you can), but you cannot do much editing with the SR1 format just yet. SR1 has a bigger view finder. SR1 has record stills on its hard drive, while the HC3 requires separate media, which is not included with the camcorder.


However, the big question is picture quality. Has anyone done a direct comparison between the two camcorders. In my judgement, the bottom line is always picture quality. When I look at the movies ten years from now, I am not going to care much what the specs were, just what I am seeing. Any thoughts or opinions would be greatly appreciated, as I have a small window to return my HC3.