chore: update docs and demo media assets

scripts/mkv-to-readme-video.sh

@@ -11,11 +11,12 @@ Description:
   Generates two browser-friendly files next to the input file:
   - <name>.mp4  (H.264 + AAC, prefers NVIDIA GPU if available)
   - <name>.webm (AV1/VP9 + Opus, prefers NVIDIA GPU if available)
-  - <name>.gif  (palette-optimised, 15 fps)
   - <name>-poster.jpg (single frame for video poster fallback)
+  - <name>.webp (animated, only when --webp is provided)
 
 Options:
   -f, --force  Overwrite existing output files
+  -w, --webp   Generate animated WebP preview
 
 Encoding profile:
   - Crop: 1920x1080 at x=760 y=200
@@ -25,6 +26,7 @@ USAGE
 }
 
 force=0
+generate_webp=0
 input=""
 
 while [[ $# -gt 0 ]]; do
@@ -36,6 +38,9 @@ while [[ $# -gt 0 ]]; do
 		-f | --force)
 			force=1
 			;;
+		-w | --webp)
+			generate_webp=1
+			;;
 		-*)
 			echo "Error: unknown option: $1" >&2
 			usage
@@ -74,7 +79,7 @@ base="${filename%.*}"
 
 mp4_out="$dir/$base.mp4"
 webm_out="$dir/$base.webm"
-gif_out="$dir/$base.gif"
+webp_out="$dir/$base.webp"
 poster_out="$dir/$base-poster.jpg"
 
 overwrite_flag="-n"
@@ -83,7 +88,11 @@ if [[ "$force" -eq 1 ]]; then
 fi
 
 if [[ "$force" -eq 0 ]]; then
-	for output in "$mp4_out" "$webm_out" "$gif_out" "$poster_out"; do
+	outputs=("$mp4_out" "$webm_out" "$poster_out")
+	if [[ "$generate_webp" -eq 1 ]]; then
+		outputs+=("$webp_out")
+	fi
+	for output in "${outputs[@]}"; do
 		if [[ -e "$output" ]]; then
 			echo "Error: output exists: $output (use --force to overwrite)" >&2
 			exit 1
@@ -98,7 +107,6 @@ has_encoder() {
 
 crop_vf="crop=1920:1080:760:205"
 webm_vf="${crop_vf},fps=30"
-gif_vf="${crop_vf},fps=15,scale=960:-1:flags=lanczos,split[s0][s1];[s0]palettegen=max_colors=128[p];[s1][p]paletteuse=dither=bayer:bayer_scale=3"
 
 echo "Generating MP4: $mp4_out"
 if has_encoder "h264_nvenc"; then
@@ -159,10 +167,20 @@ else
 		"$webm_out"
 fi
 
-echo "Generating GIF: $gif_out"
-ffmpeg "$overwrite_flag" -i "$input" \
-	-vf "$gif_vf" \
-	"$gif_out"
+if [[ "$generate_webp" -eq 1 ]]; then
+	if ! has_encoder "libwebp"; then
+		echo "Error: encoder not found: libwebp" >&2
+		exit 1
+	fi
+	echo "Generating animated WebP: $webp_out"
+	ffmpeg "$overwrite_flag" -i "$input" \
+		-vf "${crop_vf},fps=24,scale=960:-1:flags=lanczos" \
+		-c:v libwebp \
+		-q:v 80 \
+		-loop 0 \
+		-an \
+		"$webp_out"
+fi
 
 echo "Generating poster: $poster_out"
 ffmpeg "$overwrite_flag" -ss 00:00:05 -i "$input" \
@@ -174,5 +192,7 @@ ffmpeg "$overwrite_flag" -ss 00:00:05 -i "$input" \
 echo "Done."
 echo "MP4:  $mp4_out"
 echo "WebM: $webm_out"
-echo "GIF:  $gif_out"
+if [[ "$generate_webp" -eq 1 ]]; then
+	echo "WebP:  $webp_out"
+fi
 echo "Poster: $poster_out"