Z-CAM E1 Camera 100 Mbps hack for 4K DCI (fw v0.31)

storyboardcreativity

@zcream, I worked on that for some time, but I need to disassemble Ambarella's DSP microcode in firmware. I can't understand, what is the instruction set in it.

@Leemuzhko, I now don't have much time for working on this firmware, sorry.

Additional info: I have a little inside from Z Cam - I spoke to one of the developers and he said that they don't like Ambarella SoC's very much. They said that their SDK is very buggy and they don't get any support from Ambarella. Now Z Cam change their vendor because of these problems.

zcream

Is it possible to set chroma 422 in mjpeg mode? Perhaps 420 error is only for h.264

Leemuzhko

@storyboardcreativity, thank you very much for this scripts! I've founded that HD resolutions don't freeze with CBR. Bitrate is lower (65543kbps), but it is far better than it was (15Mbps). And now HD resolutions are useable. And I lowered VBR multiplier for 4K resolutions to match my Samsung EVO cards. It is interesting, because this cards can handle 135Mbps from Yi4K+ but this camera says "slow card" Anyway it is way better than it was before. And can you help me to find 4K DCI @25fps mode?

pureaxis

Finally bought a used E1, and it seems to have a native 4:3 mode in 2k, I wonder if the resolution can be bumped up like the GH4 all photo mode

Vitaliy_Kiselev

@storyboardcreativity

Yep, you have lot of fun still awaiting you :-)

storyboardcreativity

Hey, have some news. H.264 is not limited by sd-card speed. I know, these words seems funny, but it's real. When I make card slower, H.264 recording says "slow card". But when I increase bitrate instead of slowing sd-card, I get camera frozen after some seconds of recording.

What can be the reason of this behavior?

I think, that there is a buffer between DSP and File-writing threads, that becomes full before file-writing thread catches blocks. I tried to change some bytes to non-instruction to watch behavior of camera when it reaches it. Same result. Camera is just frozen.

storyboardcreativity

Got some results! Overclocked sd-card bus from 72 MHz to 84 MHz.

But I have one problem: I don't know, how it affects read/write speed (no tools to check real I/O speed).

[UPDATE] To check I/O real speed I use recording in MJPEG (I change jpeg quality - it gives me determined bitrate). Just tried to change sd-card bus frequency to 10 MHz - it really works, "slow card" message appears immediately => my script with changing bus frequency works correctly. Now we just need to understand how high can we go.

storyboardcreativity

Got info from camera about sd-card frequency: it's 72 000 000 Hz (72 MHz). I use SanDisk Extreme 32GB card (UHS-I U3).

I'll try to increase frequency (now I have an ability to check, if it works or not).

storyboardcreativity

Just found maximum allowed settings for H.264 decoder in DSP by next debug strings:

HDEC_ERR: Only chroma 4:2:0 and mono supported, chroma_idc=%d

HDEC_ERR: Only High profile 4.2 is supported, profile_idc=%d

storyboardcreativity

@Vitaliy_Kiselev, as I see, half of the binary is made of debug strings :D

Vitaliy_Kiselev

@storyboardcreativity

In such LSI code only sets lot of parameters, and it is always hardware blocks that do almost all work.

storyboardcreativity

Yes, seems like Little-Endian ARM. It will take some time to understand, how it works...

storyboardcreativity

Just found a DSP microcode (that is used for H.264 and MJPEG hardware encoder). Maybe understanding what is in it can help us to make it work better. Now I don't know, what architecture does DSP have, but I hope it's ARM.

kurth

The fact that the 1080p hack froze my camera, versus recording 10 or so seconds like the 4k hacks gave me pause, and I tried multiple times with the same result. But It's good to hear you've tested all of them and they work on your card. Yes...I know what card I need already, thank you. But I live in Mexico and just can't creditcard amazon to bring it to my door. I was able to successfully download it using edge, so it was a browser problem, but vimeo also was windowing a message that said " sorry we have a small problem" or something to that effect. @jleo...thanks for thinking of that possibility.

jleo

some browsers can lose connection during a large download and can't resume downloading, if that keeps happening, a download manager like jdownloader might be better. Usually it resumes downloading after interruptions

http://jdownloader.org

markr041

@kurth If Vimeo is truly admitting to you it has problems, then I will report that to them - exactly because I pay money so that you can download. What country are you in?

I have tested all these hacks and they work fine on my u3 V30 Sandisk microsd card. If you are going to up the bitrate, you need a faster card that is reliable.

I strongly recommend a V30 u3 Sandisk card. For example, the DJI Osmo Pocket web site has a list of recommended cards. That camera shoots at 100 Mbps, just like the E1 with hack. Your card is not listed, mine is.

kurth

@markr041...well, I've tried 6 times and it gives me a message, we're having problems. Maybe you should pay them more, or maybe you should realize that the world is a big place and not every location is the same. ps....I get about 2/3's of the file before it fails. And I've got a 200mbps fiber optic connection. 7th attempt .....downloaded 2.6gb at 6mbps at 2:23 minutes...failed again. Usually I can download a 4 gb torrent in less than 5 minutes so it ain't my internet connection.

kurth

ok....fast test. 4k, uhd 24p and dci 24p appear to be functioning, as well as 720/120p. But my 1080 24p freezes after 3 seconds. I've only got a class10 card, but I get 10-11 seconds of 4k before it stops, and when it stops, it gives me a "slow card" warning, unlike the 1080 which just freezes, and then I've got to shutdown the camera to unfreeze it. Hopefully someone with an extreme microsd card will test.

markr041

@kurth Vimeo is NOT having problems. I just now downloaded the video from Vimeo. I pay a lot of money per year to Vimeo so that people can download original videos to assess quality. Assessing the compression ability of the camera (bitrate) cannot be done based on video streams, which severely re-compress. The original is 3.6 GBs and was rendered at the same bitrate as the camera in 4K - 100 Mbps.

kurth

@markr041..problem is download has failed 3x. I think vimeo is having problems.

markr041

@kurth Are you viewing the video by streaming, or did you download the (4K) original? You want to avoid the Vimeo compression to assess, of course.

kurth

@storyboardcreativity ....perfect ! You're the man...or woman? @markr041....thanks for the test. I don't have a 4k monitor but I'm thinking I still see a little mud in the water. Could be my comp though. I'm on an internet comp not my workstation. I'd like to hear what @LPowell thinks. And @storyboardcreativity....what were you running that got mjpeg at 200mbps ?

Robby953

@ storyboardcreativity 30-minutes time limit for video: I have a E1 EU version with this limit and it would be perfectly if i could do longer recordings... best Robert

storyboardcreativity

@markr041, good job! Thank you for the tests.

storyboardcreativity

@AdvUser, released cumulative patch. It forces 100 Mb/s and All-Intra for these modes:

4K DCI 24 fps
4K DCI 25 fps
4K UHD 23.976 fps
4K UHD 24 fps
4K UHD 25 fps
4K UHD 29.97 fps
FullHD 24 fps
FullHD 25 fps
FullHD 50 fps
HD 50 fps
HD 59.9401 fps
HD 119.88 fps
HD 239.76 fps

You can find "autoexec.ash" in repository. I did not test them, can't be sure that all works correctly. Check it by yourself.

Howdy, Stranger!

Categories

Tags in Topic

Top Posters