Timelapse shorter intervals Than 0,5? Script/firmware

[fuyghjb]

You DO realize you are trying to lecture a guy.....

I realize )) This "guy "very good programmer , but not so good technician ... and its ok .

You really do not need to lecture me

ok

 

[Andy_S]

i am not a programmer, i am a hw IT specialist / unix admin.

 

[nklh]

Shutter has to be WAy faster Than 0,5 to capture sports an such..
The camera can do burst with 7 pics pr sec.
Know there will be memorycards and memoryhandling issues

so to get back to original question.

burst mode just fill the Free ram with 7 RAW of 30MB each (210MB approx)
then processing run to convert to jpeg (of 4MB approx) so 7x4 = 28MB (210 + 28 = 238MB of RAM so onlly left 18MB of ram for system)
need a UHS-3 µSD (minimal 30MB/S continuous write) to store non stop burst mode. SO if the YI does not support UHS a burstMode timelapse is impossible.
And so for a 0,2s timelapse (5FPS) you need 20MB/s write at least for the µSD.
As the YI support class10 µSD that is 10Mo/S the limite is 2 pics/s maybe 3 or 4 with peak writting but don't think it can handle it continuously.
That's why the Yi actually stay busy for a while after a burst shot.

Only way to technicaly do such things is to drop the JPEG from the RAM through the USB interface (480mbps = 60MB/s) on a device that support 30MB/s write assuming that the internal DSP + RAM can handle up those continus 7 fps ( storage + jpeg processing) so it's not possible.

 

[Andy_S]

Sadly USB can't be hooked like that - there is an option "Linux USB" for it, but it does nothing at all and does not produce any result whatsoever. . .
True, now when i think of it, i didn't test it with OTG cable & flashdrive for example... Silly me. Gotta test it today, would be lovely.

 

[fuyghjb]

burst mode just fill the Free ram with 7 RAW of 30MB each (210MB approx)

Do you really think that DSP cant converting raw to jpg in "realtime" ??

 

[nklh]

Do you really think that DSP cant converting raw to jpg in "realtime" ??

I know it does but you can't transfer it to the SD card at the same transfer rate.
And maybe the firmware is not good to handle it. as we can drop RAW from RAM from debug options, I think they are keept here until je JPEG is fully transfered.
Even with this solved with an optimised firm (no RAW possibilities), you can't transfer more than 2 JPEG(16MPix > 4MB file) by second according to class10 guaranteed writing rate.

 

[fuyghjb]

I think they are keept here until je JPEG is fully transfered.

I think it can be comressed from sensor with dsp hardware in real time , and debug function just "say" to dsp create raw file without compression. I say more . For axample ( its just examle) gopro 3+ can 4k capture with 15(?)fps . You think 8mp pictures " go to" ram in raw mode ? ) then compressed in movie )) ??

 

[nklh]

gopro had 512Mb and even the DSP use buffer. the DSP is just good at signal treatment. there is many I/O ops.
The way a video is made is not image by image to compress it has to calculate similarity between following ones and other stuffs. that's why a H264 video don't weight that much. it's complex mathematics and compression stuffs.

 

[fuyghjb]

The way a video is made is not image by image to compress it has to calculate similarity between following ones and other stuffs.

Image from sensor in raw ))) "Calculate similarity" h264 codec! and it is last stage of processing ... its after geting image from sensor , and after all image corrections ( and all this do dsp in real time )

DSP is just good at signal treatment. there is many I/O ops.

DSP its specialized chipset with codecs and specific modules realized in hardware. Its can be h264 codec, or image comressor, or sound comressor, or etc.

 

[nklh]

DSP can work in realtime but in fact the data doest not follow this way : sensor > isp > SDCard ...chipset have failure too so you need to keep the datas in highspeed memory (RAM) at least the time they are processed to prevent failure. there is security manywhere and buffer are used to.
there is electronic interferences, error and else...you have to deal with it. realtime is more like unperceptible treatment by human capacity.

 

[fuyghjb]

DSP can work in realtime but in fact the data doest not follow this way : sensor > isp > SDCard ...chipset have failure too so you need to keep the datas in highspeed memory (RAM) at least the time they are processed to prevent failure. there is security manywhere and buffer are used to.
there is electronic interferences, error and else...you have to deal with it. realtime is more like unperceptible treatment by human capacity.

I dont say that dsp not needed in ram at all, but it neds not much like you think. And not in ram problem . Problem in dsp hardware, supported or not some modes. If a7 not supported 2.7k 60 we have not cameras with a7 and 2.7k 60 )) If a9 support 2.7k 60 we have gopro 4be ))

 

[nklh]

Yes DSP is not really adaptable. but In fact it can do full HD at 60fps and the sensor can do it too. but for now it's upscalled so firmware is not fully efficient .
If the A7LS can do 4K a 15fps like the A7 does, actually it's not listed in the firmware.
Anyway we are melting thread here but to return back to timelapse possibility.
photo time lapse under 0.5s is impossible due to SD writing limits, time lapse video under 0.5s should be possible.