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-   -   Finally got the HV10 (https://www.dvinfo.net/forum/canon-vixia-series-avchd-hdv-camcorders/90622-finally-got-hv10.html)

Raphael Ranola April 4th, 2007 08:25 AM

Finally got the HV10
 
After many long hours of searching, reading reviews and asking forums, I finally made the purchase on a HV10. I was looking at the Sony HDC5 and 7 but with the price difference of the 3, I thought the Canon was a much better deal. Despite it's ergonomics, I LOVE this camera. Very clear when I hook it up to my HDTV via component. I am an amateur and the only thing I have done to cameras is press the record button. I want to learn how to use this camera to its full potential and I believe I can do so by reading through this forums. Anybody have a guide or anything like that?

Oh yeah, I went to BestBuy to get it price matched with CircuitCity, BestBuy still had it for 1399.99, CircuitCity had it for 899.99, since BB does price match I went through them (since I have that rewards card thing). Funny thing is the guy did the calculations in his head, and gave me the camera for $759.99!!!!!!!!!!! I did not say anything, lol. So I left BB with the camera and two Hidef tapes for 849 and some change!!! not a bad deal for me, especially since I went to BB.

Oh yeah, I would have waited for the HV20, but my wife is having our baby girl anytime now, I couldn't wait and take the risk of not taping her birth in HIDEF!!! lol...

Prech Marton April 4th, 2007 01:15 PM

Congratulation for your HV10!
I also buy one last week, and i'm very happy with it!
Our daughter is 1 year old.
2 screengrab here:
http://www.relaxvideo.hu/hv10-1.jpg
http://www.relaxvideo.hu/hv10-2.jpg

Amazing!

Question: can i cut the native m2t file so, that i dont need to reencode?
i just want to drop unwanted scenes.

Rune Austefjord April 4th, 2007 06:19 PM

Why edited HDV is always recompressed on export:
 
With the HDV codec, each frame is compressed, and in addition each frame inherits data from the previous few frames and on to the next few frames. The frames are compressed into GOPs (Group Of Pictures) like any MPEG2 transport stream. This means that to get valid GOPs and a valid transport stream after cutting certain frames/scenes, you need to reencode the rest, cause else you won't have a valid series of GOPs. An invalid GOP may be missing keyframes, so in playback it will appear to freeze the video until the next keyframe comes along.
That's why the editing apps like Premiere Pro and others always recompress the HDV video after editing even if you just want to export the edited HDV footage back to tape. If you have a moderately fast computer like mine, expect rendering/recompression time to be around 2x realtime, so if you have a 30 minute clip it'll render and recompress in about an hour, then export to tape.

With standard def DV recompression is not neccesary, cause each frame is compressed by itself, and only transitions and effects are recompressed. So with standard def DV export back to tape or out to DV AVIs is much quicker, in fact almost instantaneous for short clips, because the only limitation is the speed of your harddrives, and usually less than a minute for long clips (30 minutes clips or so).

Colin Gould April 4th, 2007 10:46 PM

Quote:

Originally Posted by Rune Austefjord (Post 654021)
With the HDV codec, each frame is compressed, and in addition each frame inherits data from the previous few frames and on to the next few frames. The frames are compressed into GOPs (Group Of Pictures) like any MPEG2 transport stream. This means that to get valid GOPs and a valid transport stream after cutting certain frames/scenes, you need to reencode the rest, cause else you won't have a valid series of GOPs. An invalid GOP may be missing keyframes, so in playback it will appear to freeze the video until the next keyframe comes along.
That's why the editing apps like Premiere Pro and others always recompress the HDV video after editing even if you just want to export the edited HDV footage back to tape. If you have a moderately fast computer like mine, expect rendering/recompression time to be around 2x realtime, so if you have a 30 minute clip it'll render and recompress in about an hour, then export to tape.

With standard def DV recompression is not neccesary, cause each frame is compressed by itself, and only transitions and effects are recompressed. So with standard def DV export back to tape or out to DV AVIs is much quicker, in fact almost instantaneous for short clips, because the only limitation is the speed of your harddrives, and usually less than a minute for long clips (30 minutes clips or so).

This can't be true- certainly you have to rebuild the cut GOP, but it can be shorter than a norm (15), right? the rest of the video after the rebuilt cut GOP section is just copied through unchanged (else every MPEG editor would be lossy and suckless performance.)
Admitted this is not as perfect/seamless as intraframe-compression/frame accurate DV editing, but I don't know editors that recompress EVERYTHING after a cut? certainly if you used an intermediate codec, yes, but not native M2T (Vegas) or MPEG editors (Ulead etc)..?
(for MPEG editors, you do need to recompose it back into an M2T transport not program stream, but that's just rebuilding packets not re-compressing the visual data- also fast and no PQ loss... right?)

Rune Austefjord April 4th, 2007 11:48 PM

If they just inserted a keyframe at the beginning of the cut GOP in order to retain the visual integrity of the GOP, that GOP would not be HDV compliant. Sure there are editors that do this, but they're not fully HDV compliant. You could take such a stream and transcode it to HD WMV or MOV, and it would look fine, and you could probably export it to tape too, but it would still not be fully HDV compliant.
Premiere Pro 2.0 exports fully HDV compliant MPEG2 streams back to camera deck, or exports MPEG2 to disk in an MPEG2 compliant format, that is including full GOPs determined by the contents of the videostream at the time of export. This means recoding of the entire stream. For HDV this means creating a 25mbit/sec HDV compliant MPEG2 stream, and at that bitrate the rate of loss is very small.

Some others (don't have much experience with vegas or ulead) may opt not to recompress each frame, and it may be called an MPEG2 Transport Stream, but I can't imagine it being fully HDV compliant, even though the software edits the M2T file directly, cause the signature long GOP of HDV would occasionally not be all there. This is for frame accurate editing. If you choose to do GOP accurate editing, the 60i GOP is 12 frames, and the 50i GOP is 15 frames, so you'd probably have more success editing if your source material was in 60i. GOP accurate editing is not a widely used term, but it would keep the integrity of all keyframes, I-frames, B-frames and so on within each GOP.

For true HDV format compliant export after frame-accurate editing though, you'd have to rebuild each affected GOP, and that means all GOPs after the first edited one. That's what Premiere Pro 2.0 does, and that's why it takes a while to export back to tape.


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