These are used for selecting the LiveView raw stream (aka "raw type", see PREFERRED_RAW_TYPE in raw.c).
There is a function that gives some more information about these modes: lv_select_raw in 70D, 80D, 750D/760D, 5D4 and 7D2. The debug strings also reference the PACK32 module (which is something that can write a raw image to memory), so probably this setting connects the input of PACK32 to various image processing modules from Canon's pipeline.
Some related pages: Register_Map, EekoAddRawPath, raw_twk, 12-bit raw video, mv1080 on EOSM...
The names appear to match between DIGIC 5 and 6 cameras, so here's a summary of the LV raw modes:
5D4 80D 760D 7D2M 70D 700D 100D 5D3
--------------------------------------------------------------------
0x00: DSUNPACK
0x01: UNPACK24
0x02: ADUNPACK
0x03: DARKSUB <- <- <- <-
0x04: SHADING <- <- <- <- SHADE <- <-
0x05: ADDSUB TWOLINEADDSUB <- <- <-
0x06: DEFC <- <- <- <-
0x07: DFMKII DEFMARK <- <- <- <- <-
0x08: HIVSHD <- <- <- <- <- <- <-
0x09: SMI <- <- <- <-
0x0a: PEPPER_CFIL <- <- <- <-
0x0b: ORBIT <- <- <- <- <- <- <-
0x0c: TASSEN <- <- <- <-
0x0d: PREWIN1 PEPPER_WIN <- <- <-
0x0e: RSHD <- <- <- <- <- <- <-
0x0f: BEATON <- <- <- <-
0x10: HEAD <- <- <- <- CCD <- <-
0x11: AFY <- <- <- <-
0x12: DEFOE <- <- <- <- DEFCORRE <- <-
0x13: ORBBEN <- <- <- <-
0x14: PEPPER_DOUBLE
0x15: JUSMI <- <- <- <-
0x16: SUSIE <- <- <- <-
0x17: KIDS <- <- <- <-
0x18: CHOFF <- <- <- <-
0x19: CHGAIN <- <- <- <-
0x1a: CAMPOFF <- <- <- <-
0x1b: CAMPGAIN <- <- <- <-
0x1c: DEGEEN1 <- <- <- <- DEGEEN <-
0x1d: DEGEEN2 <- <- <- <-
0x1e: YOSSIE <- <- <- <-
0x1f: FURICORE <- <- <- <-
0x20: EXPUNPACK
0x21: SUBUNPACK
0x22: PREFIFO INVALID,PRE_FIFO <- <- <-
0x23: SAFARI_IN <- <- <- <-
0x24: DPCM_DEC <- <- <- <-
0x25: MIRACLE
0x26: FRISK
0x27: CLEUR <-
0x28: OTHERS
0x29: SHREK SHREK_IN <- <- <-
0x2a: DITHER
0x2b: DFMKII2 DEFMARKII2 <- <-
0x2c: PREWIN2 PEPPER_WIN2 <- <-
0x2d: CDM <- <- <-
0x2e: LTKIDS_IN <- <- <-
0x2f: PREWIN3 PEPPER_WIN3 <- <-
0x30: SIMPPY
0x31: PEPPER_DIV_A
0x32: PEPPER_DIV_B
0x33: SUBSB_OUT
0x34: SIBORE_IN
0x35: PEPPER_DIV
DIGIC 4 has a different mapping. 60D:
RSHD => 0x0B
SHADE => 0x01
HIVSHD => 0x07
ORBIT => 0x09
DEFCORRE => 0x04
CCD => 0x05 (currently used)
DEFMARK => 0x06
There are more valid raw types than the ones named in the above tables. For example, on 5D3 (trial and error):
0x00 => valid image stream in some unknown format
0x01 => bad
0x02 => scaled by digital ISO (DEFCORRE?)
0x03 => bad
0x04 => SHADE (bad pixels, scaled by digital ISO)
0x05 => bad
0x06 => bad
0x07 => DEFMARK (bad pixels)
0x08 => HIVSHD (bad pixels, appears to fix some vertical stripes)
0x09 => bad
0x0A => bad
0x0B => bad
0x0C => bad
0x0D => bad
0x0E => RSHD (bad pixels, scaled by digital ISO)
0x0F => bad
0x10 => CCD (clean image, some vertical stripes in certain cases)
0x11 => bad
0x12 => DEFCORRE (scaled by digital ISO)
0x13 => bad
0x14 => valid image stream in some unknown format (different from 0)
0x15 => bad
0x16 => bad
0x17 => bad pixels
0x18 => bad
0x19 => bad
0x1A => bad
0x1B => bad
0x1C => bad pixels
0x1D => bad
0x1E => bad pixels
0x1F => bad
0x20 => valid image stream in some compressed format?
0x21 => bad
0x22 => clean image
0x23 => bad
0x24 => bad
0x25 => bad
0x26 => bad
0x27 => bad pixels
0x28 => valid image stream in some compressed format?
0x29 => bad
0x2A => some strange column artifacts
0x2B => bad
0x2C => bad
0x2D => bad
0x2E => some strange posterization
0x2F => bad
0x30 => valid image stream in some compressed format?
0x31 => bad
0x32 => clean image
0x33 => bad
0x34 => valid image stream in some unknown format
0x35 => bad
0x36 => bad
0x37 => bad pixels
0x38 => valid image stream with some missing columns?!
0x39 => same
0x3A => clean image
0x3B => bad
0x3C => bad pixels, strange column artifacts (like 0x2A, but with bad pixels)
0x3D => bad
0x3E => posterization (same as 46)
0x3F => bad
0x40 - 0x7F => same as 0x00 - 0x3F (checked most good modes and some bad modes)
On 5D3 and 60D, the raw type "CCD" is the one we are using for raw video.
On EOS M, the only valid raw types appear to be 7, 11, 48, 50, 75, 80, 87
according to dfort.
Would be nice if somebody has the patience to try all the raw types on the 70D, as it's the only camera that runs ML now and has lv_select_raw.