On Tue, Mar 21, 2023 at 04:57:49PM +0000, monkyyy via Digitalmars-d-learn wrote:
> My current method of making videos of using raylib to generate screenshots, throwing those screenshots into a folder and calling a magic ffmpeg command is ... slow.
[...]

How slow is it now, and how fast do you want it to be?

One possibility is to generate frames in parallel... though if you're recording a video of a sequence of operations, each of which depends on the previous, it may not be possible to parallelize.

I have a toy project that generates animations of a 3D model parametrized over time. It generates .pov files and runs POVRay to generate frames, then calls ffmpeg to make the video.  This is parallelized with std.parallelism.parallel, and is reasonably fast. However, ffmpeg will take a long time no matter what (encoding a video is a non-trivial operation).


T

-- 
Try to keep an open mind, but not so open your brain falls out. -- theboz

On Tuesday, 21 March 2023 at 17:18:15 UTC, H. S. Teoh wrote:
> On Tue, Mar 21, 2023 at 04:57:49PM +0000, monkyyy via Digitalmars-d-learn wrote:
>> My current method of making videos of using raylib to generate screenshots, throwing those screenshots into a folder and calling a magic ffmpeg command is ... slow.
> [...]
>
> How slow is it now, and how fast do you want it to be?
> T

I vaguely remember an hour and half for 5 minutes of video when its extremely lightweight and raylib trivially does real-time to display it normally and realistically I wouldn't be surprised if it could do 1000 frames a second.

Coping several gb of data to disk(that probably asking the gpu one pixel at a time) to be compressed down into a dozen mb of video is just... temp shit. I should just do something that isnt stressing hard drives extremely unnecessarily.

On Tue, Mar 21, 2023 at 05:29:22PM +0000, monkyyy via Digitalmars-d-learn wrote:
> On Tuesday, 21 March 2023 at 17:18:15 UTC, H. S. Teoh wrote:
> > On Tue, Mar 21, 2023 at 04:57:49PM +0000, monkyyy via Digitalmars-d-learn wrote:
> > > My current method of making videos of using raylib to generate screenshots, throwing those screenshots into a folder and calling a magic ffmpeg command is ... slow.
> > [...]
> > 
> > How slow is it now, and how fast do you want it to be?
> > T
> 
> I vaguely remember an hour and half for 5 minutes of video when its extremely lightweight and raylib trivially does real-time to display it normally and realistically I wouldn't be surprised if it could do 1000 frames a second.
> 
> Coping several gb of data to disk(that probably asking the gpu one pixel at a time) to be compressed down into a dozen mb of video is just... temp shit.  I should just do something that isnt stressing hard drives extremely unnecessarily.

You could try to feed the frames to ffmpeg over stdin instead of storing the frames on disk. See this, for example:

	https://stackoverflow.com/questions/45899585/pipe-input-in-to-ffmpeg-stdin

Then you can just feed live data to it in the background while you generate frames in the foreground.


T

-- 
Lottery: tax on the stupid. -- Slashdotter

On Tuesday, 21 March 2023 at 17:46:00 UTC, H. S. Teoh wrote:
> On Tue, Mar 21, 2023 at 05:29:22PM +0000, monkyyy via Digitalmars-d-learn wrote:
>> On Tuesday, 21 March 2023 at 17:18:15 UTC, H. S. Teoh wrote:
>> > [...]
>> 
>> I vaguely remember an hour and half for 5 minutes of video when its extremely lightweight and raylib trivially does real-time to display it normally and realistically I wouldn't be surprised if it could do 1000 frames a second.
>> 
>> Coping several gb of data to disk(that probably asking the gpu one pixel at a time) to be compressed down into a dozen mb of video is just... temp shit.  I should just do something that isnt stressing hard drives extremely unnecessarily.
>
> You could try to feed the frames to ffmpeg over stdin instead of storing the frames on disk. See this, for example:
>
> 	https://stackoverflow.com/questions/45899585/pipe-input-in-to-ffmpeg-stdin
>
> Then you can just feed live data to it in the background while you generate frames in the foreground.
>
>
> T

This is how I use pipe process with d and ffmpeg. I am reading video frames but other way may work too.
https://github.com/aferust/oclcv/blob/main/examples/rgb2gray-video/source/app.d