Menu

Show posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

Show posts Menu

Topics - blindcat

#1
Scripting Q&A / Exposure - PowerSave - Math
August 21, 2013, 08:12:03 AM
Hi there,
I am going to create a video bracket script. It should take automatic short clips around sunset. In the moment it is just a static script with videorecording and sleeps() with static durations. I would like to make it more flexible. But there are a few problems I have with it. I could make a thread for every single one, but I don't do it :-) It's all here.

Problem 1: With a static script my battery was empty at around 3,5 hours. But the script was not finished. Thats a problem with a static script because you can't restart it. So I have questions on power saving. Currently  a snippet of the script for one recording looks like:


// ****
movie_start(); // 17:00
sleep(180);
movie_end();
printf("Video 01 taken, wait 17 min! \n");
display_off();
lv_pause();

sleep(1020); // wait 17 min

display_on();
lv_resume();

// ****
movie_start(); // 17:20
....


and so on ... Display on/off and lv pause/resume are the only functions listed in alex api description. In fact the display was not off during the waiting times. The display went black, yes, but in the upper left corner there where always the last three lines of console output (e.g. printf statements) visible. If I would code not a static output of the waiting time, but a countdown this would be nice. But if it prevents me from powersaving, and I could do all my clips with one battery, I would prefer this. So the question: Display was not really off, did I do something wrong? Order of statements? And is there more I can do to save power?

Problem 2: Unfortunatly I haven't found a good ressource on PicoC in general. Are there any math methods usable in PicoC? I am looking explicit for trigonometric functions like sin(), cos(), arccos() and calc of degrees (rad and deg). If not, are arrays supported to create my own tables (or is this out of reach with memory?)?

Problem 3: PicoC (I use nighly build from 1st may 2013 on 5D2) is the best documented scripting opportunity here in the forum. Unfortunatly it's not in the nightly builds anymore and it is said that it will be replaced with tcc. I read that tcc is available in some builds but I haven't found some so far. On the other hand tcc scripting is nearly not documented anywhere in the forum. As far as I understood the PicoC API(?) is not ported to tcc yet. What I interpret as there are no functions like get_iso() or set_iso() etc.. And I don't understand if I compile in camera or have to precompile in a linux environment. At the moment I can't setup a linux environment. So the question is what is the future of PicoC (It has no future as I can read :-((( ... and when will tcc will be fit enough to replace PicoC with all the functionality PicoC had in it's last development milestone? And when will TCC will be as documented as PicoC is now (what is not perfect but a good point to start)?

Problem 4: Back to some practical: I need some information on the current exposure for my script. I want to calculate the main settings for exposure by some math functions depending on the date and time of the recording. But I can only do this for sunny weather. Clouds are changing the game, and so it would be usefull to read something from the camera for the exposure in reality. Then I can compare that to calculated values and correct them on the fly for cloudy days. Thats the idea for the script (btw. when I did some tests ... I was stepping through a value. When I checked the images on the computer, I see that the values have not been set ... bug? timing? I had secondlong sleeps between the calls).
Audionuts pointed me to the auto exposure module from pradovmil. That's a nice module but I am not sure in the moment how it interacts with videorecording? And in the future there is hopefully a script function like  start_raw_movie(), a auto-exposure for the settings in raw video mode and so on ... so I dont stick to the h.264 canon video.

I know there are several new ideas and alpha functions for all this cool fancy stuff like scripting, raw recording, exposure auto and ettr, dual iso and more to come. I understand that they are just in development and interaction especially of new ideas and functions is therefore everything else than perfect. On the other hand I don't understand why something thats working quite good as the PicoC Interpreter is out of the game. Especially when there is no equal replacement.
Thanks for patience ...
- Frankie