View Full Version : Problem with AVCHD transcoded footage


Giles Moriarty
April 2nd, 2009, 09:53 AM
hello all,

This is my first post in this forum, and I am asking for an opinion regarding AVCHD.
I have a Sony HDR SR5 camcorder.
The AVCHD footage looks very good when played back on my PS3.

However, when I edit the footage by importing it in to Mac applications, such as iMovie o8 or FCE4 the footage gets transcoded in to Apples' AIC codec.
After the edit, the resulting .MOV file or .MP4 file has quality issues.
When the camera pans, the focus is lost and items seem to 'drag' across the screen.
When I pause the footage during a pan an item in the field of view seems to have 3 images a central 'hard' image and a softer 'ghost' like image to it's immediate left and right.

This problem exists in both the AIC files and the subsequent output file which is an MP4 format for the PS3.

Since these issues only arose after the transcode to AIC and subsequent editing and transcoding again to .mp4 I was wondering if I purchased the application from Cineform, NeoScene, to perform the transcode to .mov, would this resolve my issue at all?

Or will I have to abandon my iMac and edit the footage on my XP windows machine using Sony Vegas?

Michael Murie
April 2nd, 2009, 11:49 AM
I think iMovie 08 doesn't convert at full resolution.

Do you have the latest update of FCE 4? you want to have 4.0.1 They added AVCHD 1920 x 1080 projects and you have to use that to get the same quality as is in the camera.

I'm not sure this will address your description of ghosting, but it's the first thing to start with.

Giles Moriarty
April 2nd, 2009, 12:21 PM
Hello,

The HDR-SR5 records in 1440 x 1080/50i.
So I told FCE to import 'AVCHD - Apple Intermediate Codec- 1440 x 1080 /50i'.
As far as I can tell this is the right import setting.
The movies imported OK, it's only after they get saved as AIC codec they go bad.
Personally I am starting to think this is a problem with interlaced footage then being treated as progressive. Could that be it?

Michael Murie
April 2nd, 2009, 01:54 PM
Ahh...I wasn't familair with the specs for the SR5..

What settings are you using to export the movie? Perhaps that's the problem. If you shoot in 1440 x 1080/50i, and you are editing and exporting in that format, then you shouldn't be able to see a significant difference between the original and the edited footage....

Giles Moriarty
April 2nd, 2009, 02:02 PM
Well, I have tried all sorts, all with the same issue,
MPEG4 at 1280x720 25fps
MPEG4 at 1440 x 1080 25fps
MPEG 4 at 960 x 540 25fps

Could it be that the 25fps is the problem (seeing as the footage was shot at 50i)?

Michael Murie
April 2nd, 2009, 02:20 PM
I supect it's interlacing you're seeing (there's an example in this discussion: De-interlacing? Final Cut Express? iMovie? Canon HV-10 - Mac Forums (http://forums.macrumors.com/showthread.php?t=317427)) Basically you are shooting an interlaced video, then outputting an MPEG4 as basically a progressive format....BUT you should basically see the same effect when playing back the original and the output....unless the PS3 is doing some kind of deinterlacing on the original (interlaced) files, and not on the progressive MPG4 files (which it might be.) Getting a bit out of my depth here, so take that as wild speculation...

There's some suggestions in the above thread about using QuickTime Pro to output the file and deinterlace it for you, which *might* solve the problem....

Giles Moriarty
April 2nd, 2009, 02:58 PM
Hello,

Yes, I am starting to suspect the interlacing may be the issue.
I guess I will start running tests with the de-interlace filter in FCE4.

Thanks for your replies, it's much appreciated.

Michael Murie
April 2nd, 2009, 08:10 PM
Basically, I think I need to do a better job of basically proofreading my comments before posting. Basically.

I must have had that word on the brain.


Hope you manage to figure it out. I'd be curious to find out what's going on.

Giles Moriarty
April 3rd, 2009, 12:05 AM
Michael,

So I am off to Scotland today, hoping to get some great footage of the Caingorm Mountains, and the lochs in Spring.
So I will have lots of footage to experiment with. I will let you know if I fix the issue, but I suspect I will have to use a mixture of iMac and Windows editing.

We will see.

Perhaps I should buy a new camera that shoots in progressive instead of interlaced, oh well too late now!

Bye for now...

Michael Murie
April 3rd, 2009, 07:27 AM
Wow, sounds like fun! I'd be interested to see what you come up with.

Though progressive might ultimately be a little more desirable, I think you should be able to solve the problems (or at least get around them) without going to Windows!!!

You might also want to post again your question in the Non-Linear Editing Mac section. Perhaps some people who don't check out this section will have some suggestions there!

Giles Moriarty
April 13th, 2009, 10:13 AM
Michael,

Well, back from Scotland. I have had some interesting video results.
I went to my PC and downloaded a trial copy of Sony Vegas Movie Studio Platinum 9.00. Let's call it SVMSP for ease of typing.
Next I used the Motion Picture Browser Software that came with the Camcorder and transferred the footage to my hard drive. This was really quick to do and very easy.

Next, I started SVMSP9.
I was able to select the clips, edit them, make transitions, add music, all the usual stuff.
Then I exported to disc still in the native AVCHD format (.m2TS).

Then I took that file and moved it to my PS3.
It played perfectly, absolutely perfect. It was interesting that the data rate was 15 MBPS while watching the footage - very high.

So, I would conclude for now, that the footage is best kept in the native AVCHD format, and until Apple come up with a suite that can handle AVCHD natively, I will be doing my editing in SVMSP9.
Looks like I am going to have to purchase a copy (boo!).

I am not giving up on MC editing, just have not found a solution to my issue yet.

If you would care to see the footage I will be glad to get it to you... somehow, any ideas (I will have to translate them to .mp2 unless you can play AVCHD .M2TS files).

regards

Giles Moriarty
April 16th, 2009, 12:41 AM
So,
I think I have found the answer to the problem with AVCHD footage in FCE or iMovie.
in each case I had the import setting set to 1920 x 1080.
My footage is 1440 x 1080 (older camcorder).
The next setting in iMovie is 960x540. If I import at 960 x 540, edit then export at 960 x 540 all the problems I had vanish like magic.

The same goes for FCE, I just had to select the correct input size (or lower) i.e. 1440 x 1080.

Actually I may well stick with 940 x 540 as I see precious little difference between the resolutions on my TV and the files are so much smaller and easy to manage.

Now to investigate iMovie 09, seeing as it has the ability to use chapter markers and archive AVCHD.

Excellent!

Ike Tamigian
April 21st, 2009, 09:28 PM
You may want to read this very interesting blog post(not mine):

Eugenia’s Rants and Thoughts Blog Archive Stay AWAY from iMovie/FCE (http://eugenia.gnomefiles.org/2009/04/11/stay-the-fuck-away-from-imoviefce/)



hello all,

This is my first post in this forum, and I am asking for an opinion regarding AVCHD.
I have a Sony HDR SR5 camcorder.
The AVCHD footage looks very good when played back on my PS3.

However, when I edit the footage by importing it in to Mac applications, such as iMovie o8 or FCE4 the footage gets transcoded in to Apples' AIC codec.
After the edit, the resulting .MOV file or .MP4 file has quality issues.
When the camera pans, the focus is lost and items seem to 'drag' across the screen.
When I pause the footage during a pan an item in the field of view seems to have 3 images a central 'hard' image and a softer 'ghost' like image to it's immediate left and right.

This problem exists in both the AIC files and the subsequent output file which is an MP4 format for the PS3.

Since these issues only arose after the transcode to AIC and subsequent editing and transcoding again to .mp4 I was wondering if I purchased the application from Cineform, NeoScene, to perform the transcode to .mov, would this resolve my issue at all?

Or will I have to abandon my iMac and edit the footage on my XP windows machine using Sony Vegas?

Giles Moriarty
April 24th, 2009, 11:20 AM
Thank you for the direction to these comments. They are absolutely right in what they say and what is said matches my experience exactly.
However, I have tried Sony Vegas on my PC, just as was suggested and I found that although I could edit the files just how I wanted them, another problem arose when playing the resulting files back on my Sony PS3.
It was really strange, at a given point in the movie (about 15 minutes I think) the file would start to play at double speed and the bit rate would drop by 50%! Nothing I could do would resolve this.

So, as I was using the trial of Sony Vegas I decided not to pay for the software as clearly there was an issue (either on the PS3 or with the files themselves).

So I have had to compromise. The iMovie 09 and FCE 4 that I have will just have to do until Apple decide to allow us to edit AVCHD in it's native form (if ever!).

I find that iMovie 09 is quite good and I am now willing to live with the compromise, especially regarding the file sizes.

It is a very poor show from Apple that they will not let us edit AVCHD in it's native form.
For now, I am going to 'live with it' and try to stop fretting over something I can't change.

Craig Hollenback
April 28th, 2009, 07:14 PM
We shoot only in 30p and it behaves fine in FCP 6.0?
Best, Craig