In my TV dir:
3310 avi
86 mp4
56 mkv
13 MPG
Note that pretty much all new SD TV is switching from xvid/avi to x264/mp4 currently/in the near future, so that ratio will start to slowly change. eg: Game of Thrones switched to mp4 with s02e07, and I havent tried that yet since I'm not that far in the show.
The one I'm currently trying to get working is an avi with a .sub (I said .srt before, I was mistaken). I can't run any actual tests till I get home tonight, but here's a silly amount of info till then.
When I get home, I'll set it to always convert, restart MC and the Xbox just to be sure, and see if I can't get some output after doing that.
Subtitle Mode: Show subtitiles only if selected... or if subtitles are in a sidecar file
Default Sub language: English
Default audio language: English
mediainfo Game\ of\ Thrones\ -\ s01e07\ -\ You\ Win\ or\ You\ Die\ -\ SD\ DVD.avi:
Complete name : Game of Thrones - s01e07 - You Win or You Die - SD DVD.avi
Format : AVI
Format/Info : Audio Video Interleave
File size : 550 MiB
Duration : 55mn 25s
Overall bit rate : 1 387 Kbps
Writing application : VirtualDubMod 1.5.10.2 (build 2540/release)
Writing library : VirtualDubMod build 2540/release
Video
ID : 0
Format : MPEG-4 Visual
Format profile : Advanced Simple@L5
Format settings, BVOP : 2
Format settings, QPel : No
Format settings, GMC : No warppoints
Format settings, Matrix : Default (H.263)
Muxing mode : Packed bitstream
Codec ID : XVID
Codec ID/Hint : XviD
Duration : 55mn 25s
Bit rate : 930 Kbps
Width : 624 pixels
Height : 352 pixels
Display aspect ratio : 16:9
Frame rate : 25.000 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Compression mode : Lossy
Bits/(Pixel*Frame) : 0.169
Stream size : 369 MiB (67%)
Writing library : XviD 64
Audio
ID : 1
Format : AC-3
Format/Info : Audio Coding 3
Mode extension : CM (complete main)
Codec ID : 2000
Duration : 55mn 25s
Bit rate mode : Constant
Bit rate : 448 Kbps
Channel(s) : 6 channels
Channel positions : Front: L C R, Side: L R, LFE
Sampling rate : 48.0 KHz
Bit depth : 16 bits
Compression mode : Lossy
Stream size : 178 MiB (32%)
Alignment : Split accross interleaves
Interleave, duration : 40 ms (1.00 video frame)
Interleave, preload duration : 500 ms
mediainfo Game\ of\ Thrones\ -\ s01e07\ -\ You\ Win\ or\ You\ Die\ -\ SD\ DVD.sub
General
Complete name : Game of Thrones - s01e07 - You Win or You Die - SD DVD.sub
Format : MPEG-PS
File size : 54.7 MiB
Text #1
ID : 189 (0xBD)-32 (0x20)
Format : RLE
Format/Info : Run-length encoding
Muxing mode : DVD-Video
Text #2
ID : 189 (0xBD)-33 (0x21)
Format : RLE
Format/Info : Run-length encoding
Muxing mode : DVD-Video
Text #3
ID : 189 (0xBD)-34 (0x22)
Format : RLE
Format/Info : Run-length encoding
Muxing mode : DVD-Video
Text #4
ID : 189 (0xBD)-50 (0x32)
Format : RLE
Format/Info : Run-length encoding
Muxing mode : DVD-Video
Text #5
ID : 189 (0xBD)-51 (0x33)
Format : RLE
Format/Info : Run-length encoding
Muxing mode : DVD-Video