Batch conversion to overwrite existing files in multiple folders and subfodlers

[kaledi]

I'd like to batch convert a very large number of JPEGs and these are held within multiple folders and subfolders within a root folder.
I can see how to load all files into the batch conversion tool, including those from subfolders. I can also see how to overwrite existing files. All good.
However, what I can't seem to find is the setting to set the output folder to be the same as where the file originated from the folder and file structure remains the same.

[Bhikkhu Pesala]

The Advanced Batch option [x] Create subfolders in destination folder does what you want, but if your source files are in My Pictures, it will recreate the full path in the destination folder, e.g. Users\Username\Pictures\JPEG\ ...

[FenceFurniture]

I have a similar (ish) problem to solve please. The overview of what I want to achieve is how do I get the files from more than one folder (on the same folder-tree level) into Irfan? I do not want to do all the folders on that level in one go (it will tie up the processor for too long, and is a bit risky - but I do have backups)

I have thousands of pics in a master folder (M:\2.2 Music ARTWORK\) which has hundreds of sub-folders.
They are mainly jpg but there are 875 png files that I want batch convert.
Not every sub-folder has png files in it, and there may be a mix of jpg and png in the same sub-folder.

I have isolated all the png files using the Win 10 search option in the folder, searching for *.png
I want to convert them to jpg, with a change of size, save the new jpg in the same folder, and delete the original png files.

I know I can open the first file in each folder in Irfan and batch that folder of png through, but that is going to be a bit slow and tedious (it was ok for doing the tif files because they were only in a handful of folders).

However, what I would like to do is:
NOT do all of the root folder "Include subfolders" which, as far as I can tell, will create a whole bunch of new sub-folders that I will then have to go and find to move around,
AND
NOT do them one folder at a time
I want to drag (say) 50 files at a time out of my *.png search into Irfan, change the size, save the new jpg in the same folder, and delete the original png files. These will come out of an unknown number of folders.

Can it be done? I'm thinking it probably can't because in Batch Conversion I can only look at one folder on that folder-tree level.

[JendaLinda]

IrfanView itself can't do that. You have to write a batch script to process the folders recursively and call IrfanView for each file. This example might be useful:

https://stackoverflow.com/a/25381530

[FenceFurniture]

IrfanView itself can't do that. You have to write a batch script to process the folders recursively and call IrfanView for each file. This example might be useful:
https://stackoverflow.com/a/25381530

Thanks for your reply. I'm afraid I have no knowledge on how to do that, and wouldn't know what to replace with what in that example, or where to execute it from, or how to call Irfan. That all means I could do significant damage!