Xah Talk Show 2026-06-25 Ep797. write emacs lisp command to convert png to webp, of image tag in 10 thousand html files

https://youtu.be/ZOXCigQmVA0

Video Summary (Generated by AI, Edited by Human.)

In this episode (Ep797), Xah Lee demonstrates how to optimize a website by converting thousands of PNG images to the WebP format. He walks through his personal Emacs Lisp workflow for image processing and file management.

Key Highlights of the Process:

Image Conversion (0:52 - 19:54): Xah demonstrates using custom Emacs commands to convert images to lossless WebP, noting significant file size reductions (e.g., saving 20MB across a batch of images).
Batch Processing and Automation (16:33 - 19:48): He shows how to select files in Emacs, move them to temporary directories for bulk processing, and then "unravel" them back to their original locations.
Link Maintenance (11:25 - 34:35): After converting images, Xah uses a Go script to validate internal links across 13,000 HTML files, addressing broken paths created by the change in file extensions.
Tools and Philosophy: Xah highlights his reliance on custom, private Emacs packages and command-line tools from Google (cwebp). He discusses his lack of money for his previous open-source releases.
Discussion Topics:
Wolfram Language (34:57 - 42:17): Xah shares his perspective on Wolfram Language (Mathematica), emphasizing that it remains far superior to open-source alternatives like Python, SageMath, or Maxima for high-level mathematical computation.
AI in Coding (42:17 - 50:42): He expresses being impressed by AI's ability to generate tutorials (e.g., for Rust, CSS Grid, and Makefiles), noting that while AI has limitations, it often outperforms the "copy-paste" tutorials found on common web forums.
Generational Perspectives (50:42 - 56:42): Xah engages in a discussion regarding the impact of AI and modern technology on the capabilities of the younger generation, questioning whether the accessibility of information is leading to a decline in foundational problem-solving skills.

2026-06-16

demo emacs commands xah-dired-to-lossless-webp and xah-dired-to-lossy-webp

git commit xah lee dot info

convert all png to webp in talk show dir.

view and compare file size

fix all links in html

do a site link check
Golang: Validate Website Local Links 📜

2026-06-25

(defun xah-dired-to-lossless-webp (zfiles)
  "Create a webp version of images of marked files in `dired'.
Call external command cwebp.

Created: 2026-06-18
Version: 2026-06-21"
  (interactive
   (let ((xflist
          (cond
           ((eq major-mode 'dired-mode) (dired-get-marked-files))
           ((eq major-mode 'image-mode) (list buffer-file-name))
           (t (list (read-from-minibuffer "file name:"))))))
     (list xflist)))
  (let ((xoutbuf (get-buffer-create "*xah-dired output*" t)))
    (message "doing xah-dired-to-lossless-webp. wait")
    (mapc
     (lambda (x)
       (let ((xnewname (concat (file-name-sans-extension x) "_ll" ".webp")))
         (call-process "cwebp" nil xoutbuf nil "-lossless" x "-o" xnewname)))
     zfiles))
  (dired-revert))

Emacs: Xah Fly Keys 📦