serious quality loss with MTS files and iMovie '11

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serious quality loss with MTS files and iMovie '11

Hello,
I have some issues with my brand new Panasonic HDC SD700 (a full HD camera)
I experience serious quality loss when I use iMovie to create a movie.
I did some tests, but still puzzled int this world of codecs and formats.
Maybe some of you can help.

I have made a short shot of 450 sec with highest mode (1080p 24fps)
It show is finder as a .MTS file size 99MB, I'm very happy with the quality when I play this with VLC.
iMovie turns this file into a .mov file with 635MB size, in Apple Intermediate Codec, Linear PCM, Timecode. This quality is already poor compared to original MTS file.
No wonder that the output file (select 1080p H.264 codecs) results also in unacceptable quality.

I'm running latest imOvie version with all updates etc.
I have no idea were to look to solve this issue. It is quite annoying since I have invested in a top Cam recorder. Not sure is Final cut express will sure the issue either.....

iMac 11.1 with quad core Intel i5, Mac OS X (10.6.5)

Posted on Dec 24, 2010 8:35 AM

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Answer 1

Filmpje Author

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Dec 24, 2010 12:47 PM in response to Filmpje

I did some more digging and read @ wiki the following

BEGIN excerpt
.Apple's Final Cut Express 4, Final Cut Pro 6.0.1, and iMovie '08-'09 (iMovie is bundled with all new Apple computers; Final Cut Express and Pro are sold separately) do not support editing of AVCHD clips directly. Imported AVCHD clips are automatically converted into the Apple Intermediate Codec format, which requires more hard disk space (40GB per hour as opposed to 13.5GB per hour for Standard Definition DV), a more powerful machine (an Intel-based Mac), and a more recent OS (Mac OS X 10.5). Final Cut Pro 6.0.5 "logs and transfers" the footage from AVCHD to AppleProRes by default and also gives the option of converting to the Apple Intermediate Codec. It does not allow native transferring of the *.m2ts clips nor directly editing them. The latest release of Apple's iLife suite (specifically, iMovie) has added support for AVCHD Lite cameras and camcorders.[69][70]

END excerpt
I'm not sure if this conversion is the cause of my quality drop ?
I was not aware that iMove could not handle native AVCHD footage, quite disappointing I must say

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Answer 2

Dec 24, 2010 11:39 PM in response to Filmpje

iMovie will not edit "native" HDV or AVCHD files because those codecs use interframe compression -- it is extremely difficult for a computer to make frame-by-frame edits since picture information spans several frames. Any such movie files have to be converted to an intraframe-based codec like ProRes (Final Cut Studio only) or AIC. (Back in the old standard-definition days, programs could edit standard DV because it used intraframe compression. In the days of HD, things are more complicated.)

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Answer 3

Filmpje Author

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Dec 25, 2010 12:20 AM in response to shaynewhite

Hello,

OK understood. Main questions remains my quality drop before and after iMovie with MTS footage shots. Is this translate the cause or is there something else I'm overlooking ?

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Answer 4

Dec 25, 2010 1:56 AM in response to Filmpje

Not sure what's happening with your set-up and workflow, but I recently imported to iMovie '11 some AVCHD clips (,MTS files) shot at Full HD (1920 x 1080). On import I used the Full setting and used various transitions and titles when editing. I exported at HD 1080p (1920 x 1080) using the preset under Share to Media Browser.

The exported movie showed excellent quality, particularly when viewed through my Western Digital TV Live HD Media Player on my widescreen LCD TV (HD 1366 x 768). The WD Media Player is capable of showing video at 1920 x 1080. Friends commented on how clear the video appeared on the TV.

Just wanted to reassure you that you can get excellent results with .MTS files, but it may be an "eye of the beholder" thing!

PS. I notice that you have posted in the iMovie '09 forum, but your question relates to iMovie '11 - so I guess you are, in fact, using iMovie '11.

John

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Answer 5

Dec 25, 2010 6:42 AM in response to John Cogdell

I exported at HD 1080p (1920 x 1080) using the preset under Share to Media Browser.

The video can be viewed here:
http://www.youtube.com/watch?v=E-62sN9yy_Q

If you are able, view as 1080p HD in Full Screen to see the full quality. Total running time is 3 minutes 25 seconds.

John

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Answer 6

Filmpje Author

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Dec 25, 2010 1:34 PM in response to John Cogdell

John,

Thx for your reply quite helpful to read that you do get good results. I did check the import settings, they were at full quality. I export as 1080p (same as original. My output is a bit blurry and colors are a bot pale. Your movie on youtube looks very good!
Not sure what others tuning I can do within iMovie. I did some more testing and noticed that I lease most of the quality after rendering not so much when the M<TS file is converted into the Apple footage.

And yes you are right I'm using IMovie '11, quite confusing that '11 means version 9.0 ;-(

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Answer 7

Dec 25, 2010 8:33 PM in response to Filmpje

I have made a short shot of 450 sec with highest mode (1080p 24fps)

Have you tried shooting at the PAL standard of 25fps? I checked the specs for your Panasonic but didn't see any mention of a 24fps mode, but most reviews seem to miss mentioning the shooting modes. If you did indeed shoot at 24fps, did you choose this frame rate when importing to iMovie '11?

I export as 1080p (same as original. My output is a bit blurry and colors are a bit pale.

Did you use the 1080p preset under Share to Media Browser, or Export using QuickTime? If the latter, be sure to select an appropriate data rate - if set too low this may result in poor quality output.

And yes you are right I'm using IMovie '11, quite confusing that '11 means version 9.0

Yes - very confusing! In the forums, iMovie versions are generally referred to by their year number, not version number. It's a pity that we have version 9.0 (iMovie '11) and iMovie '09.

Glad you liked the video - it looked very clear on YouTube at 1080p Full Screen, at least to my ageing eyes!

John

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Answer 8

Filmpje Author

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Jan 3, 2011 6:42 AM in response to John Cogdell

@

I did some more testing. My camera shoots 1920*1080 50i with 18MB/s bitrate.
When I try the option to export wiht QT 7 I do get better results still a degradation compared to original MTS file. I export with a MP4 container and H.264 codec at 1080p. Bitrate 24Mb/s seems to give best result. The colors are still plae compared to MTS file and I loose sharpness and detail. I would appreciate some input here as it feels like aiming with my eyes closed.

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Answer 9

Jan 6, 2011 2:45 AM in response to Filmpje

I may have missed this in earlier posts, but did you try exporting at HD 1080p using the preset under Share to Media Browser? That's how my YouTube video was shared and I am very happy with the result (even after processing by YouTube). AppleMan1958 has also reported that he is seeing excellent results using this export option, following imports at Full (1920x1080).

Having said this, your QuickTime 7 export settings look fine. I might try those settings on my Baby Animals video, just as a comparison with the HD 1080p preset. When done, I'll report back.

John

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Answer 10

Jan 6, 2011 4:32 AM in response to Filmpje

I don't think there is a 1080P preset in iMovie 09. I would try the following settings.

SHARE/EXPORT USING QUICKTIME
Choose QuickTime Movie, h.264, bit rate 20mbps, key frames automatic, or 10.

OR

Choose MPEG4, h.264, bit rate 20 mbps, key frames auto or 10.

If this produces acceptable results, you may be able to reduce the bit rate to 16 or even 8 to produce a smaller file.

==========

Another thing to check. When you import from the camera, be sure to import on Full (1920x1080), not LARGE (960x540).

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Answer 11

Jan 6, 2011 4:38 AM in response to AppleMan1958

I don't think there is a 1080P preset in iMovie 09

No, there isn't one in '09, but the OP is actually using iMovie '11 (I queried this earlier on). There's lots of confusion now with having version 9 (iMovie '11) and iMovie '09 and the OP has posted in the wrong forum unfortunately 🙂

John

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Answer 12

Jan 6, 2011 4:40 AM in response to John Cogdell

OK Sorry.

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Answer 13

Jan 6, 2011 5:00 AM in response to AppleMan1958

No worries AppleMan!

Actually, I noticed that when I looked at exporting my Baby Animals video using "Export Using QuickTime" (to test against my HD 1080p preset export), the current size showed as 960 x 540.

This is odd because I definitely imported as Full (1920 x 1080) and exported using the HD 1080p preset. The only conclusion I can come to is that the resolution was knocked down given that I had used a transition (Doorway) which uses scaling. Remember the posts by Steve Mullen where he recommended not to use certain titles, transitions, backgrounds etc.? He maintained that using these caused a drop in resolution and he mentions the issue in his e-book. This all related to iMovie '09, but may still be an issue with iMovie '11.

Are you also seeing this AppleMan - or perhaps you are not using any of the "troublesome" effects?

Note that I haven't proceeded with my QuickTime export as yet, as I haven't had a chance to get back to it.

John

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Answer 14

Filmpje Author

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Jan 6, 2011 2:09 PM in response to John Cogdell

Let me test these options and I will come back.
Thanks for your input!

PS: I did report this issue to Apple as it seems odd to me that 1080p export option gives such a bad result. It degraded a very good camera into a moderate video.

PS: I'm testing with a plain fragment, no editing

Regards from a rainy Netherlands

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Answer 15

Jan 6, 2011 4:37 PM in response to John Cogdell

I have not noticed this, but I will be watching for it. I haven't been able to get into iMovie today.

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