Output as H.264 - blurry | default folder

Question

I am an occasional user of Premiere CS4 on Mac OS 10.6.8, with no in-depth knowledge of the technical aspects of video export. In the past, I have used the default settings with one difference (see below) to achieve good results. In my current project, which uses exactly the same workflow as previous ones, I encounter 2 difficulties:
The output is blurry
AME insists on using the same folder for saving the output files as for the previous project. I have over 500 files to save, and I don't want to have to select the right folder manually each time.
Here's a screenshot comparing the source and the output, and showing the settings:
http://dev.lexogram.com/forum/h264Export.jpg
The only change from the standard H.264 format is the dimensions: 320 x 240 pixels. This has not caused blurriness in previous projects.
To avoid black lines around the output, I need to choose 360 x 245 pixels as the source area (or a similar ratio). Why is that? Does this give a clue as to what the problem is?
Many thanks in advance for insights into how to solve these two problems.
James

Answer 1

Hi able123,
Thanks again for your input and your support with this issue.
able123 wrote:
your source stuff is 720x480 according to your posted pic. You seem to be sorta framing the mouth of person for export at 320x240 ? How about trying 360x240 which would "halve" your source size ?
The output format is required to be 320 x 240. 360 x 240 would have worked, but it wasn't the choice that was made at the start of the project.
are all your clips going to be mouth shots of people talking and do they need to be separate movies ?
It's all the same person and yes, it needs to be separate movies. It's for an application to help people who have suffered from a stroke to see which muscles they need to move to create each kind of sound. The user can play the same short video over and over again to understand the movements.
If your clips are all similar to the one posted...why not start a project that is 360x240 ... Does that work ?? 
That would mean starting over again from the beginning. I have already created over 500 subclips and tweaked the In and Out points, and it took several days of work. It would be great just to be able to export the existing subclips without any blur, just as I did for previous versions of this product in other languages.
From what you say, I am guessing that the blur comes from the changed ratio of the image. To get an output at 320 x 240, with no black borders, I need to crop the source at 360 x 245 (or a similar ratio). This is what I don't understand: why is the output not the same ratio as the source? How can I export, pixel for pixel, a cropped section of the source?
I am hoping that there is some simple setting that I have modified by mistake, and which I can simply set right and all will work the way it did before. However, the video was not recorded with the same camera. The 3 previous versions were recorded on 3 different cameras, and this version on a fourth. It was recorded on tape and then imported from the camera into iMovie. I don't know how the previous recordings were made. Is this likely to be an issue?