AVCHD hell - please help « Videomaker Community Forums

arthouse
Member

Hi everyone.

I've looked on various posts relating to AVCHD issues but I still feel like these haven't addressed my specific problem and at the fear of repeating previous posts, I hope you don't mind me starting a new thread.

I've just finished the filming stage of a corporate video (as a project, unpaid) and now that I have come to the editing stage I seriously misunderstood the amount of PC power needed to edit in HD (having never shot in HD before).

As part of this project we were provided equipment by the college and as it turned out we were given SONY HDR-SR12 cameras which shoot in AVCHD at a frame rate of 60i (as I understand it) which were stored as a .m2ts file format. I shot in FULL HD - 1920 x 1080.

I usually edit with Adobe Premiere Pro CS3 by was horrified to find that CS3 doesn't support AVCHD. Even if I did edit in CS3, my PC hasn't been previewing the .m2ts files smoothly (in Sony's Picture Motion Brower - i.e - PMB) so my system would not be able to cope.

After discovering this, I took the footage into the college media suites which are fast Macs running Final Cut Pro. Again, I couldn't import AVCHD files natively. What am I supposed to do in this situation? I don't understand why the college would even use AVCHD cameras if their software don't support it.

So - after all of this, I've decided that my only real option is to convert the .m2ts files to standard definition so that I can edit them on my PC in Premiere Pro CS3 and so that the PC can actually manage the footage and get a workable edit.

In Sony's PMB there is an option to convert the .m2ts files to MPEG-2 but the results have been a little mixed. When I play back a converted MPEG-2, footage filmed with a tripod appears good quality but if for example the camera moves or it's handheld footage, the images flickers (horizontally) quite considerably. I'm confused as to whether this is due to the conversion settings (frame rate etc) or whether it is just because I am reviewing it on a computer. I've also looked at it through a standard flatscreen TV (via an HDMI cable from my PC) but it still flickers.

My questions are, should I be converting to MPEG-2?

The .m2ts video is 60i, 1920 x 1080.
The converted MPEG-2 video states that it is 25 fps, 720 x 576 (1.4587), Audio 48000, 32 bit.

Should this conversion be posing a problem?

Does 60i video need to be converted to a particular standard definition frame rate?

Bottom line is - can anyone tell me the exact conversion settings I need to convert AVCHD 60i .m2ts to standard definition? And what FREE software does this, enabling control over conversion settings?

Sorry for the long-winded post, I'm at my wits end!

Many thanks.

arthouse.

Posted 2 years ago #
birdcat
Moderator

I use a Sony SR11 (identical to the SR12 with a smaller hard drive).

The MTS files (AVCHD) are too compressed for my Pentium 4 w/1GB RAM to process - I use a product called AVCHD Upshift from NewBlueFX (http://www.newbluefx.com/avchd-upshift.html) which converts them to lightly compressed M2T (MPEG-2) files which Sony Vegas Pro 8 has no problems with on the same machine.

This will keep your project in HD and let you edit without problems (assuming you can use MPEG-2).

Bruce Paul
7Squared Productions
http://www.7squared.com

Posted 2 years ago #
Orram
Member

Hi,

I cant. see if you shooting pal or ntsc but you say that you shoot 60i so when you convert these m2ts files to mpeg2 they should be 29.97 frames instead of 25. Maybe that is the problem.

Posted 2 years ago #
arthouse
Member

I've managed to encode all of my .m2ts files to H.264 files as PAL DV Widescreen (using Adobe Media Encoder). This took a long time as you can imagine but during playback small horizontical lines appear periodically and seem to be more apparent when there is movement in the shot. I'm in the UK so we operate under the PAL system but should I be converting to NTSC (29.97 fps)? And would this solve the image issues?

Very confused on this. Any help would be great.

Also, as a separate query, if I want to burn my final edit onto a DVD, what format should I output to? I've tried AVI so far but the image is not as crisp as I would like it and any graphics I've created in Premiere Pro seem less crisp too (a little blurred).

Thanks.

Posted 2 years ago #
birdcat
Moderator

If you're going to standard DVD, your output should be MPEG-2 for video and AC3 for audio.

Posted 2 years ago #
Rob Grauert
Post Production Host

NTSC = 60i (which is the same as 29.97fps) 720X480 resolution

PAL = 50i (which is the same as 25fps) and 720X576 resolution

Look at the footage you shot and check what format you recorded. Make your project settings match your footage. A lot of these HD cameras can record both NTSC and PAL. So if you live in the UK and shot 60i, you shot the wrong format.

I suggest you edit in the format you recorded, and if it's the wrong format for your region, convert at the end of your project.

The problem with AVCHD is the compression, as stated above. It's too compressed. AVCHD, like MPEG, uses Long GOP compression. Frames of video share data with one another. So for the computer to display one video frame, it needs to pull data from MANY frames of video. That is a lot of data to sort through on the fly, which is why many computer cant handle it.

The BEST solution in my opinion is to convert to an i-frame codec before you begin editing. This is the opposite of Long GOP. Frames of video are encoded with all the data they need to be fully displayed, so now your computer only has to look at the one frame. Much easier for your CPU even though the file sizes are larger. I-frame codecs include DV, DVCPro50, DVCPro HD, and ProRes(FCP Only).

I dont suggest converting to MPEG. MPEG isn't even an editing codec. It uses Long GOP compression too. Just because you can bring it into an NLE, doesn't mean it's an ideal codec for editing! H.264 is not an editing codec either.

If you're going out to DVD, MPEG2 is the ONLY option for output. That is what DVD players read. And ONLY JUDGE THE QUALITY OF YOUR IMAGE BY LOOKING AT A BROADCAST MONITOR OR TV AT WORST!!!!!! Computer screens aren't accurate, especially if it's SD footage that you're lookin at.

Rob Grauert, Jr
http://www.robgrauert.com
http://command-r.tumblr.com

Posted 2 years ago #
claycope
Member

Just a quick thought on this. Another option is to download a trial version of Sony's Movie Studio, which handles the .mts files without conversion to do your editing. You can download a 30 day trial version or purchase a copy for under $100.

For reference, I record video with the Panasonic AG-HMC40 in 1920x1080 60i (also produces the .mts files), use a laptop (Intel dual core 2 GHz / 2G RAM) and it works with HD files just fine. It's not lightning fast, but it gets the job done. My 2nd camera is a consumer JVC HD camcorder, which produces .TOD files. Sony Movie Studio also works these files as well with no conversion. Good luck and let us know how you decided to progress.

Posted 2 years ago #