AVCHD editing and conversion

[alaskamovieguy]

I am producing a 52 min avchd to dvd project, editing in PE7, exporting out as H264 and then authoring in Corel as avchd onto dvd. I've been doing this successfully for awhile now but never this large of a project before. I divided the editing into 2 seperate parts so as to have smaller projects and then combined them into 1 52 min project. My main question is about all the converting that takes place and wondering if I can reduce it somewhere. I am starting with avchd, rendering it in PE7 which creates dv-avi, ( conversion # 1 ), exporting as H264 ( conversion # 2 ), converting back to avchd in Corel ( conversion # 3 ). Also, when I render in PE7 creating dv-avi and then export as H264, does PE7 convert straight to H264 or does it re-render to dv-avi a second time and then convert to H264? Additionally, sometimes ( as in this project ) when I export from PE7 ( 11 hours! ), the program hangs in the last 5 seconds and I loose the conversion ( very frustrating! ) Any help would be appreciated!
Bob

[Bob]

Hi Bob,

As long as you have selected an AVCHD project preset and aren't exporting to DV-AVI, PE7 isn't converting your AVCHD footage to DV-AVI. As for AVCHD to H.264 conversions, AVCHD uses H.264 so there won't be a conversion there either. However, there may be recompressions when you export from PE7 and when Corel creates the avchd dvd.

It's not clear why the program hangs at the end. Do you have enough free disk space on both your system drive and your video work drives?

[alaskamovieguy]

Thanks for the response Bob. In Steve's book about PE7, on page 102, he says "Everything goes thru the process of becoming a DV-AVI before PE7 encodes it as anything else". So..if that's correct, and if I'm understanding this correct, when I render the files while editing so the avchd plays more smoothly, that is converting the avchd into dv-avi? I'm wondering now if I should just export the edited product out of PE7 as a dv-avi and then let corel convert that to avchd for the burn, thereby eliminating one conversion. Also, my understanding of avchd is that it is a futher compression of H264, so that even if I didn't render the avchd file while editing when I export it as a H264 it is making a conversion? As for my system drive available disk space, I had about 20 GB while I had tons of space on my external drive which has the source files.

[Chuck Engels]

Technically there isn't any conversion going on that you can really use.
Premiere Elements creates AVI preview files that it uses to playback the project timeline.
This happens when there is a red line above your clips on the timeline and you press the Enter key to render the timeline. The files are created for preview purposes only not for anything else.

[John 'twosheds' McDonald]

..... Additionally, sometimes ( as in this project ) when I export from PE7 ( 11 hours! ), the program hangs in the last 5 seconds and I loose the conversion ( very frustrating! )Bob

Hi Bob. Sometimes it looks like the program may have 'stalled' but it is still running. Is any error or other message produced? How long do you wait before deciding that the program has hung?

As for my system drive available disk space, I had about 20 GB while I had tons of space on my external drive which has the source files.

If I have understood correctly you have 20Gb available on the system drive(?). It could be that the 20Gb on the system drive just isn't enough space for workfiles/temp files for this particular project. Can you free up any more space on that drive? (I suggest this as a possible cause as I recently partitioned my system drive to enable a temporary dual boot whilst I migrate to Win 7. I now have 15Gb available as workspace and I am having similar problems).

[alaskamovieguy]

Thanks Chuck. That explains the 'render' process. I thought an actual conversion to dv-avi was taking place.

[alaskamovieguy]

Thanks John. There were no error windows but I let it run for about 15 min with no change. It got down to the last 5 seconds when it hung. I will clear up more space on my HDrive and see if that makes a difference. Another question...When I try to export as a dv-avi, either from the share option or file/export movie, I am not given the 1920 x 1280 option, only 720 x 480? My source file is 1920 x 1280, my project settings are avchd full HD 1920 x1280. I hadn't realized this until now, after I broke my project into 2 halves, the second half being the dv-avi added back into the first halve which was avchd. So my question is, it doesn't appear that I can use Steve's suggestion of breaking a large project into parts, 1 part being a dv-avi when using the 1920 x 1280 dimensions?

[Bob]

I don't know when it changed, but recent versions of Premiere Elements support TWO preview file formats -- AVI and MPEG2. High definition projects, including AVCHD, will get MPEG2 preview files. You can easily verify that by looking in the project preview files folder after rendering previews.

Don't confuse rendering preview files with rendering your exported video files. When rendering your exported files, Premiere Elements goes back to the source media files, decodes them as needed applying any edits or effects, and encodes the output frames to the target format as needed. You don't get intermediate conversions/compressions.

[alaskamovieguy]

I don't know when it changed, but recent versions of Premiere Elements support TWO preview file formats -- AVI and MPEG2. High definition projects, including AVCHD, will get MPEG2 preview files. You can easily verify that by looking in the project preview files folder after rendering previews.

Your correct Bob! I checked those files in the project preview folder and they are mpeg. Any idea why I can only export 720x480 when I export as dv-avi?, either using the 'share' method or file/export/movie.

[Bob]

Any idea why I can only export 720x480 when I export as dv-avi?

NTSC DV-AVI is fixed at that resolution by the dv specification. If you want a different resolution, you'll need to use something else.

If you aren't going to be importing/exporting many cycles, mpeg2 would work. If you are, converting to a lossless (or near lossless) intermediate codec such as cineform or lagerith would be worthwhile. Many convert avchd to the cineform intermediate codec (not free) for editing to ease the processing overhead of avchd. Search this site for neoscene or cineform for in-depth discussions.

[Chuck Engels]

I always thought you could change the size of the AVI to anything you wanted under that advance options.
Can't you make the AVI export 1440 x 1080 or anything else? It isn't really stuck to just 720 x 480 is it?
What about PAL format AVI, that's bigger.

[Bob]

DV-AVI is constrained by the specification. If you export or share a DV-AVI file, you can't change the frame size. And, yes, ntsc and pal have different frame sizes as defined by the specification.

If, instead of Microsoft DV-AVI, you select Microsoft AVI as the file type when using file>export>movie, you can specify larger frame sizes. However, those are not DV-AVI files and use a different codec. Share only provides for DV-AVI.

[Chuck Engels]

Ahhh, now I understand. Thanks Bob

[Chuck Engels]

In version 8 all of the AVI options are under the Share tab, no more File/Export/Movie

[alaskamovieguy]

Thanks to all for clairifying some issues I had. I think I will just export my sections as H264 and then combine them in Corel where I burn to dvd. If I have problems with that, which I don't expect I will, then I'll try the cineform. Again, thanks.