With Panasonic TM700 as the popular camcorder in 2010, I also got one as 2011 New Year gift. I like the 1080/50p recording mode, and it provides great quality. I recently use Corel VideoStudio Pro X3 as my editing software, and it plays the .m2ts files from Panasonic TM700 cam quite fast and fluid. The real-time display of m2ts files at 50p is great. However, Corel X3 does not support converting the m2ts files to mp4 with frame rate higher than 30. At least, I do not find the way to get 50p mp4.
I also tried Sony Vegas, but it is very slow and horrible to use unless your computer is equipped with i7 or others. When looking for the workaround to keep 1080/50p from M2TS to MP4, I tried Aunsoft MTS/M2TS Converter, which does not include the annoying and silly limitation in the custom settings for MP4. Personally, I would give Aunsoft MTS/M2TS Converter almost 5 stars, but it does not include many editing functions like transitions, text. But it is still a good M2TS convert on Windows, and works as the alternative to Corel X3.
Below is the quick guide for my experience on converting Panasonic TM700 M2TS to 1080/50p MP4 on Windows.
Step 1. Download Panasonic 50p videos to Aunsoft MTS/M2TS Converter.
Connect Panasonic TM700 camcorder to computer via USB cable, copy and transfer the .m2ts files from cam to computer hard drive. Run Aunsoft MTS/M2TS Converter as the best 1080/50p M2TS converter on Windows 7, click the "Add" button to load the 1080p .m2ts videos. Alternatively, you can drag and drop the .m2ts files for conversion.
Step 2. Choose MP4 format with 1080/50p.
Click the "Format" option, and move the mouse cursor to HD Video > H.264 HD Video(*.mp4) as output format. You may also choose other formats like .mkv, .mov, .wmv according to your preferences.
Step 3. Set 1920x1080 video size.
To get 1080/50p videos, click the "Settings" button and type 50 as the frame rate. For users with 1080/60p videos, you can also type 60 as output video frame rate.
Step 4. Convert Panasonic M2TS to MP4 with 50fps on Windows.
Click the convert button under the preview window, the Panasonic M2TS converter will start the conversion from Panasonic HDC-TM700 M2TS to 1080/50p MP4 on Windows.
After the conversion, you will get MP4 videos with 50fps frame rate from the m2ts camcorder files.