How to compile jpeg images into timelapse video, on-demand?

[OldGeek]

I would like to compile a series of webcam .jpg images into a video and serve it from my website host. The complication is that I want to do this, on-demand, so that the video is always current (i.e., the previous 3-hours).

Any assistance wil be appreciated.

[TreeTops]

Pretty sure that Sony Movie Studio can take a series of images and make a video. There are scripts that can do the video broadcasting from your website and update it at a time specified. The hard part is that you must upload a video every three hours or at least upload a series of videos that can be displayed at a time you pick. Lots of work involved here. Easier to just link to a embedded YouTube video and have the link change every 3 hours with a script (to another video)

[jagabo]

You could build the video from the images using ffmpeg but you'll need to figure out the names of the images that constitute the last three hours. They'll need to be sequentially numbered or you can put their names in an ordered list (text file). For example, this ffmpeg command line:

ffmpeg -f image2 -r 24.00 -i %%08d.jpg -vcodec libx264 -pix_fmt yuv420p -preset slow -crf 18 -sar 1:1 "output.mp4"

will build output.mp4 from:

00000000.jpg
00000001.jpg
00000002.jpg

until it reaches the last jpg file of the sequence.

[pandy]

You need some script capable to display sequence images... alternatively some video that can be reedited on the fly (similar to FIFO concept - new frame added, first frame removed)...

[OldGeek]

You could build the video from the images using ffmpeg but you'll need to figure out the names of the images that constitute the last three hours. They'll need to be sequentially numbered or you can put their names in an ordered list (text file). For example, this ffmpeg command line:

ffmpeg -f image2 -r 24.00 -i %%08d.jpg -vcodec libx264 -pix_fmt yuv420p -preset slow -crf 18 -sar 1:1 "output.mp4"

will build output.mp4 from:

00000000.jpg
00000001.jpg
00000002.jpg

until it reaches the last jpg file of the sequence.

This may work as the filenames will be fixed (a nice feature of Blue Iris). Any idea how ffmpeg would handle nonexistent or missing files (if any)?

Also, I would have to see if I can run FFmpeg on my host's server.

[jagabo]

ffmpeg will stop at a discontinuity in the sequence. Ie, the video will only include the images up to the discontinuity. I don't know if there's a switch to make it ignore discontinuities. Or you could build a list of filenames. The list would have the format:

file '00000000.jpg'
file '00000002.jpg'
file '00000003.jpg'

and it wouldn't matter if the list didn't include a particular number. Obviously, the missing file would not be in the resulting video. Replace the input specification on the command line from "-i %%08d.jpg" to "-i list.txt ..."

ffmpeg is cross platform so there should be a version for your OS.

[OldGeek]

ffmpeg will stop at a discontinuity in the sequence. Ie, the video will only include the images up to the discontinuity. I don't know if there's a switch to make it ignore discontinuities. Or you could build a list of filenames. The list would have the format:

file '00000000.jpg'
file '00000002.jpg'
file '00000003.jpg'

and it wouldn't matter if the list didn't include a particular number. Obviously, the missing file would not be in the resulting video. Replace the input specification on the command line from "-i %%08d.jpg" to "-i list.txt ..."

ffmpeg is cross platform so there should be a version for your OS.

Good info - sounds like it will take some time to sort out, but I'll work on it when I have some time. Thanks!

[Cornucopia]

The problem I see with this is that "time lapse" refers to a sequence of still images that when combined will play at faster than real-time. IOW, a sequence of 3000 pictures with one picture shot every second (equalling 3000 seconds, but played at 30 frames per second = 100 seconds' worth of video. But it is using TIME COMPRESSION. And at some point you are going to be running out of past events and will be in the present, and you cannot speed that up any further. From that point on, you cannot be doing a "time-lapse" in the same sense that you were.

Scott

[OldGeek]

The problem I see with this is that "time lapse" refers to a sequence of still images that when combined will play at faster than real-time. IOW, a sequence of 3000 pictures with one picture shot every second (equalling 3000 seconds, but played at 30 frames per second = 100 seconds' worth of video. But it is using TIME COMPRESSION. And at some point you are going to be running out of past events and will be in the present, and you cannot speed that up any further. From that point on, you cannot be doing a "time-lapse" in the same sense that you were.

Scott

Scott -

I understand your logic, however, for my purpose, "timelapse" means a series of images taken at fixed intervals, e.g., 1/minute. The capture device will always store the most recent 180 images (for 3-hours of data).

og

[Cornucopia]

But does each capture-by-the-minute shot play for 1 minute?

Scott

[OldGeek]

But does each capture-by-the-minute shot play for 1 minute?

Scott

No, each image only constitutes one frame.

[budwzr]

But does each capture-by-the-minute shot play for 1 minute?

Scott

No, each image only constitutes one frame.

Therein lies the rub.

[OldGeek]

@jagabo:

Thanks for pointing me in the right direction. I was able to create a video, locally, using this:

ffmpeg -y -f image2 -i f:\timelapse\cam6_%03d.jpg -filter:v "setpts=2.0*PTS"  -vcodec libx264 -an -pix_fmt yuv420p -preset fast -crf 23 -sar 1:1 "c:\temp\timelapse.mp4"

Now I have to see if I can install FFmpeg on the hosting server and create/deliver the video, on-demand.