As you probably have guessed from the latest developments (
QEMU,
EDMAC graphs,
JPCORE,
EEKO), our understanding on how LiveView works has improved considerably. Finally, all my fiddling with QEMU,
at first sight with little or no purpose for the everyday users, starts paying off.
Today, Magic Lantern proudly announces new ground-breaking features that were previously thought impossible or very hard to achieve.We proudly present....4K RAW Video Recording! 
DOWNLOADTwitter announcement
On the 5D Mark III, you now have the following new resolutions:
* 1920x960 @ 50p (both 1:1 crop and full-frame - 3x3 pixel binning) - continuous
*)* 1920x800 @ 60p (same as above) - continuous
*)* 1920x1080 @ 45p and 48p (3x3 binning) - continuous at 45p
*)* 1920x1920 @ 24p (1:1 square crop) - continuous
*)* 3072x1920 @ 24p (1:1 crop)
* 3840x1536 @ 24p (1:1 crop) (corrupted frames at 1600)
* 4096x2560 @ 12.5p (1:1 crop) - continuous
*) at 8 FPS
* 4096x1440 @ 25p (1:1 crop)
* Full-resolution LiveView: 5796x3870 at 7.4 fps (128ms rolling shutter) - continuous
*) at 5 FPS!
* Full-width LiveView - decrease vertical resolution in the crop_rec submenu, all the way to 5796x400 @ 48 fps
The last feature complements the well-known
full-resolution silent pictures - the new implementation will be usable at fast shutter speeds, without the
exposure gradient - but with rolling shutter (just like regular LiveView frames).
*) Continuous recording for the above resolutions can be achieved as long as you can get a
LJ92 compression ratio (compressed / 14-bit uncompressed) of about 50-55%, with preview set to Frozen LV (previously known as Hacked Preview) for an additional speed boost. Otherwise, you'll have to reduce the resolution or the frame rate.
The following table shows how compression rate changes with ISO and bit depth; please check the figures for your particular scene in the raw video submenu, as they can vary a lot, depending on the scene content.
Bits per pixel 14 12 11 10 9 8
ISO 100 1/100 61% 53% 50% 48% 46% 43%
ISO 200 1/200 62% 54% 51% 49% 47% 44%
ISO 400 1/400 63% 54% 51% 49% 47% 45%
ISO 800 1/800 65% 55% 52% 50% 48% 46%
ISO 1600 1/1600 67% 56% 53% 50% 48% 46%
ISO 3200 1/3200 70% 57% 53% 50% 49% 47%
ISO 6400 1/6250 76% 60% 55% 52% 50% 48%
ISO 12800 1/12500 79% 63% 57% 53% 50% 49%
Credits: Greg (
full-width LiveView), g3gg0 (
video timer,
DIGIC registers documentation and lots of other low-level insights).
Complete list of new video modes:
/* 24p 25p 30p 50p 60p */
[CROP_PRESET_3X_TALL] = { 1920, 1728, 1536, 960, 800 }, /* 1920 */
[CROP_PRESET_3x3_1X] = { 1290, 1290, 1290, 960, 800 }, /* 1920 */
[CROP_PRESET_3x3_1X_48p] = { 1290, 1290, 1290, 1080, 1080 }, /* 1920; 1080p45/48 <- 50/60p in menu */
[CROP_PRESET_3K] = { 1920, 1728, 1504, 760, 680 }, /* 3072 */
[CROP_PRESET_UHD] = { 1536, 1472, 1120, 640, 540 }, /* 3840 */
[CROP_PRESET_4K_HFPS] = { 2560, 2560, 2500, 1440, 1200 }, /* 4096 half-FPS */
[CROP_PRESET_FULLRES_LV] = { 3870, 3870, 3870, 3870, 3870 }, /* 5796 */
What else could you wish for?
FAQWhere's the catch?This is only a very rough proof of concept. It has not been battle-tested and has many quirks. Some of them may be easy to fix, others not so. In particular:
* It feels quite buggy. I'm still hunting the issues one by one, but it's hard, as Canon's LiveView implementation is very complex, and our understanding on how it works is still very limited.
* Write speeds are high. For example, 10-bit 4096x2500 at 15 fps requires 180 MB/s. 1080p45 should be a little more manageable at 111 MB/s.
* Canon preview is broken in most modes; you need to use the grayscale preview in the raw recording module.
* High-resolution modes (in particular, full-res LiveView) may cause trouble with memory management. This is very tricky to solve, as we only get 3 full-resolution buffers in LiveView, with restrictions on the order in which they must be freed, and lots of other quirks.
* Since these settings were pushed to limit, the risk of corrupted frames is high. If it happens, decrease the vertical resolution a bit (
from the crop_rec submenu).
* When refreshing LiveView settings, the camera might lock-up (no idea why). Pressing MENU twice appears to fix it.
May I fine-tune the new modes?Yes! I've included some of the knobs on the user interface. Normally you shouldn't need to touch these buttons, but if you do, you might be able to squeeze a few more pixels.
Does it work with FPS override?Sort of. It's not reliable at this point, so it's best not to try yet.
Overheating?During my tests, I didn't manage to get a sensor temperature higher than 60 degrees. Your mileage may vary.
Risks?This mod changes some low-level sensor parameters that are not well understood. They were all figured by trial and error, and there are no guarantees about the safety of these changes.
As usual, if it breaks, it's your fault, sorry.
Will it work on other camera models?I hope so; however, this is an area where I hope to get contributions from others (yes, from you). If these new features don't motivate you to look into it, I wonder what else will.
I'll explain how all this works in the coming days or weeks.
Is it difficult to port to other camera models?So far, the 3x3 720p mode from crop_rec was ported to EOS M (rbrune), 700D (dfort) and 100D (nikfreak). So it shouldn't be that hard...
Will you port this to my camera model, please?No, sorry. I have better things to do - such as, preparing the April 1st prank for next year
Wait a minute, didn't you say you are primarily a still photo user? Why are you even doing this?If you look close, the usefulness for video is fairly limited, as the write speeds (and therefore the recording times) are not practical.
But the full-resolution LiveView is - in my opinion - very useful for still photo users. Although the current implementation is not very polished (it's just a proof of concept), I hope you'll like the idea of a 7.4 FPS burst mode, 100% silent, without shutter actuations.
Right now, you can take the mlv_lite module with pre-recording and half-shutter trigger: at 10 bits per pixel, you get 5 frames pre-recorded, and saved to card as soon as you touch the half-shutter button. Or, you can capture one frame for each half-shutter press, with negative shutter lag! (since the captured frame will always be pre-recorded).
And if a burst at 7.4 fps is not enough, you may also look at the 4K modes (12-15 fps).
(I know, I know, GH4 already does this, at much higher frame rates...)
The help menu for full-res LiveView says 5796x3870, but MLV Lite only records 5784x3856. What's going on?The raw recording modules have a couple of alignment constraints (e.g. can only start cropping from a multiple of 8 pixels, and the size of the cropped area (that goes into the MLV file) must be multiple of 16 bytes (that is, W*bpp/8 + H mod 16 must be 0).
To capture the full resolution, you may use the silent picture module. However, this module is not the best when it comes to memory management and buffering. Currently, you'll get an impressive buffer of 2 frames in burst mode
But hey - it outputs lossless DNG!
What about that lossless compression routine?It's included, although I didn't manage to test it much. There is a lot of room for improvement, but for a proof of concept, it seems to work.
update: also got lossless compression at reduced bit depths (8...12-bit).
P.S. The initial announcement was disguised as an April Fools joke, just like the original
crop_rec.
Twitter announcementFrom original April Fools post:
With our latest achievements in wizardry with ARM programming and DIGIC reverse engineering, we can speak of a new era of raw video recording.
On models like the 5D Mark III, the next upcoming releases will feature an improved version of our crop_rec module that delivers the following new resolutions:
* 1920x960 @ 50p (both 1:1 crop and full-frame - 3x3 pixel binning)
* 1920x800 @ 60p (same as above)
* 1920x1080 @ 45p and 48p (3x3 binning)
* 1920x1920 @ 24p (1:1 square crop)
* 3072x1920 @ 24p (1:1 crop)
* 3840x1600 @ 24p (1:1 crop)
* 4096x2560 @ 12.5p (1:1 crop)
* Full-resolution LiveView: 5796x3870 at 7.4 fps (128ms rolling shutter).
The last feature complements the well-known full-resolution silent pictures - the new implementation will be usable at fast shutter speeds, without the exposure gradient - but with rolling shutter (just like regular LiveView frames).
Please understand that providing the source code for those highly DIGIC optimized routines is a bit troublesome and will need some extra legal care. After this step is taken and as soon we are finished with ensuring the product quality you are used from Magic Lantern, we will upload the code to our repository.
Consider this being a huge leap towards our next mind boggling goal:
8K RAW Video Recording!
Sample DNG from 5D Mark III, to show that our proof of concept is working:
8k.dng
Stay tuned for more information!
