Excellent. This may have one or two downsides (which may or may not matter to you). If you deinterlace to 50p, the file size usually doubles, but the quality is great (especially with a good deinterlace algorithm like yadiff2).
I'm not bothered about file size yet. If I have to use large files for the editing/production process and it makes it a more manageable process then I can accept it.
If you deinterlace to 25p, then you lose the feel of motion of 50i (like going from "soap opera" feel to "movie" feel) and you get more artifacts than just shooting 25p to start with.
I'm not sure what I'm deinterlacing to but believe and hope it is 50p.
The output from ffmpeg on the original file is:
Input #0, mpegts, from 'g-test1.MTS':
Duration: 00:00:12.55, start: 0.701467, bitrate: 16450 kb/s
Stream #0.0[0x1011]: Video: h264, yuv420p, 1920x1080 [PAR 1:1 DAR 16:9], 50 tbr, 90k tbn, 50 tbc
Stream #0.1[0x1100]: Audio: ac3, 48000 Hz, stereo, s16, 192 kb/s
The output from the transcoded avi file is:
Input #0, avi, from 'g-test1.avi':
Duration: 00:00:12.57, start: 0.000000, bitrate: 409239 kb/s
Stream #0.0: Video: huffyuv, yuv422p, 1920x1080, PAR 1:1 DAR 16:9, 50 tbr, 50 tbn, 50 tbc
Stream #0.1: Audio: ac3, 48000 Hz, stereo, s16, 192 kb/s
I haven't yet looked into the different figures but the only obvious other than bitrate is the tbn figure. Given that the original clip was created with the 'red' video button, I understand that that produces 50i. As I created the avi file with a deinterlace switch I hope that the new file is therefore 50p, but there isn't anything that confirms this.
I'll have to investigate a method of checking this.