Hi all,
Anyone know of a library similar to OpenCV that can be used from D to create MP4 files from a series of images? I think I came across some mention of OpenCV bindings, but I can't find it now.

Any help would be most welcome and appreciated. Thanks.

On Monday, 19 August 2024 at 18:18:57 UTC, Ron Tarrant wrote:

dcv might be something you are interested in looking at.
I've used dmagick + process pipes to ffmpeg myself, and found it pretty straightforward (dmagick might be heavy for your use, if it's just simply image loading there'll be more lightweight libs available I imagine).

Jordan

On Tuesday, 20 August 2024 at 03:32:03 UTC, Jordan Wilson wrote:

Thanks, Jordan. I'll check those out.

On Monday, 19 August 2024 at 18:18:57 UTC, Ron Tarrant wrote:

If you know how to use ffmpeg as a library then there’s very good bindings in the form of ffmpeg-d. If you have never used ffmpeg as a library then I’ll send you a warning: the API is confusing, the documentation is vague, and every example you can find online will use deprecated/removed functionality somewhere.
Other than that, the existing options for encoding videos in D are pretty sparse. I would love to write some bindings to try and help the situation, but I’m not sure what libraries would be good. Are there any C/C++ libraries that developers prefer for video encoding, decoding, and manipulation?

On Thursday, 22 August 2024 at 14:01:50 UTC, IchorDev wrote:

Just to add that importC works pretty fine against ffmpeg, and it's a big plus as ffmpeg API is pretty fluid from release to release.

On Thursday, 22 August 2024 at 14:01:50 UTC, IchorDev wrote:

LOL! That's very comforting. :)

I saw an initial stab at creating OpenCV bindings, but it hasn't been touched in years. Perhaps that might be of interest?

On Wednesday, 11 September 2024 at 07:26:32 UTC, Ron Tarrant wrote:

I suggest to go directly for ffmpeg usage, importC is pretty usable with that.
It's pretty low level, but it's the common engine for a bazar of external tools.

/P

On Monday, 19 August 2024 at 18:18:57 UTC, Ron Tarrant wrote:

import std;

void main()
{

   // A mp4 1fps (-r 1) with standard settings
   auto pp = pipeShell("ffmpeg -y -r 1 -f png_pipe -c:v png -i - -c:v libx264 -crf 24 test.mp4", Redirect.all);

   // Feed frames from stdin
   pp.stdin.rawWrite(std.file.read("/path/to/your/frame1.png"));
   pp.stdin.rawWrite(std.file.read("/path/to/your/frame2.png"));
   pp.stdin.rawWrite(std.file.read("/path/to/your/frame3.png"));

   // Flush & close stdin
   pp.stdin.flush();
   pp.stdin.close();

   // Wait for ffmpeg to finish the job
   pp.pid.wait();
}

Andrea

On Wednesday, 11 September 2024 at 16:23:16 UTC, Andrea Fontana wrote:

import std;

void main()
{

   // A mp4 1fps (-r 1) with standard settings
   auto pp = pipeShell("ffmpeg -y -r 1 -f png_pipe -c:v png -i - -c:v libx264 -crf 24 test.mp4", Redirect.all);

   // Feed frames from stdin
   pp.stdin.rawWrite(std.file.read("/path/to/your/frame1.png"));
   pp.stdin.rawWrite(std.file.read("/path/to/your/frame2.png"));
   pp.stdin.rawWrite(std.file.read("/path/to/your/frame3.png"));

   // Flush & close stdin
   pp.stdin.flush();
   pp.stdin.close();

   // Wait for ffmpeg to finish the job
   pp.pid.wait();
}

If you want to create a .y4m file without ffmpeg, here is old code (probably doesn't really build anymore):

• https://github.com/p0nce/y4m-d let's you create a .y4m
• https://github.com/p0nce/y4m-tools for manipulating such files
• in particular, creating a YUV frame necessitate conversion from sRGB such as in https://github.com/p0nce/y4m-tools/blob/master/shader-capture/source/app.d#L359