Pre transcoding question(s)

I'm totally newbie so have patience please?
Sony BDP-S5100


Wow, exciting to have found mezzmo - to be able to browse my movies via my Sony DVD player.
I'm having fun but I thought that mezzmo can stream the .iso files. I tried to play one but it didn't work "There is no playable file." So I thought I would transcode it to MKV using the pre transcode feature.

I ripped the DVD using DVDFab 8. I rip only the main movie, not the entire DVD.

1. I wanted to pre transcode my .iso movie. I selected the one and the choice was to add it to the pre transcode list, so I did that. Then it asks which device so I picked my Sony DVD player. I chose to transcode to MKV. But surprisingly Mezzmo added lots of files to the list, none of them with .iso extensions but with .avi, .mp4, .mkv, and others.
What I was expecting is that one single .iso file to be pre transcoded. Did I make some silly mistake?

2. Does pre transcoding make a new different file and then delete the original? If so, I don't want my original .iso files to be deleted.

Some answers:

• Mezzmo does stream DVD ISO files directly to your device(s). If your device supports playing DVD ISO video, then your DVD ISO videos are streamed directly or, if not supported, then Mezzmo will transcode them on-the-fly so they can be played.
• To transcode just one video, right-click on the video in Mezzmo and click 'Pre-transcode Files'. In the Pre-transcode Files dialog, select your device and click 'Choose Formats'. In the Pre-transcode Formats dialog, select the bolded format and click OK. Then click OK to start transcoding. Your file will be listed in the Transcoding pane in Mezzmo. Once transcoding has completed, try streaming your video now.
• If you have lots of files mistakenly listed (queued up) in the Transcoding pane, you can remove them right-clicking the Transcoding pane and clicking 'Delete All'.
• When Mezzmo transcodes a file, it makes a new file and stores it in your transcoding folder. The location and size of this folder can be set in the Transcoding Settings dialog in Mezzmo. Mezzmo never deletes or replaces your original files.