Aspect ratio issue

[Frederic]

Hi,
I am trying to capture a video from a Sony Digital 8 (NTSC) through Matrox video tools. I cannot seem to be able to capture the video in the right aspect ratio (320x240) in MJPEG format to then rework in MSP. Do I really have to capture in 352x240, then resize my final video in MSP to 320x240 or is there something I am missing? This seems to be a lot of trouble and time lost to have a video look like the original when played back on a PC screen...
Frederic

[SteveR]

I went through exactly the same issues. I need 320x240 format for display on PC but the MJPEG codec only allows 352x240 (or equivalent formats).

I normally capture uncompressed RGB at 320x240 using av_io, then use the Panasonic encoder to convert to mpeg after editing. Most of my stuff is short enough that the 2GB limit is not an issue. Otherwise the Panasonic encoder will resample a 352x240 to 320x240 while converting to mpeg at the expense of taking a longer time to do the conversion. (Who knows, maybe the panasonic folks will bring out a plug-in for MSP in addition to Premiere which will allow conversion of multiple 2GB avi's). I have also dropped capture rate to 15/sec on occasions to get more minutes into a 2GB file, and stitched mpegs using camels's mpeg join.

For other software codecs (or if you are prepared to use MSPs mpeg encoder) the 2GB is less of an issue as you can capture to multiple files using uncompressed RGB, do your editing then compress to the final file from MSP. If you do not need to edit you could try capturing directly to compressed RGB using a software codec with av_io. I have been able to capture to 320x240 at 25/sec without frame drops using Indeo 5 set to Quick Compress and 100% quality.

If you want to play the files on a PC other than your own then they would need to be highly compressed for portability anyway, and you would need to convert them to something other than Matrox MJPEG.

[fluggo99]

Well....I think it more depends on what your goal is.

If you're for presenting things on the PC or the web, then yes, you must either capture with MJPEG at 352x240 and scale down or you can try like SteveR and do RGB at 320x240. That is, if you want your video to look exactly like the original. The difference is so small to me I just leave it in the bite-size MJPEG format.

If you're for editing and putting back to tape, then just try to ignore the difference. It will appear on your TV the same way it appeared before it was captured onto your PC. (You would run into the same difficulties, I would imagine, using the DV port on your camcorder; the aspect ratio isn't right in the DV format, either.)

[Sinsurgent]

My problem is the oppostite, when I capture in mjpeg, it looks fine on the pc but the aspect is messed up on the tv.

[Frederic]

Thank you both for your responses,
I am finally back to my video edition project and yes, this is to render back to a PC screen rather than TV. I live in the US (NTSC) but send my videos back to my family in Switzerland (PAL) on CD because I don't have a way to record in PAL here.
I now understand better what I need to do to keep the image aspect as close to the original as possible thank to you.

Frederic