commit b410cf6d30e70ae5057fc0698422c1f0b5e53858
parent 69259af52c815d64657b5c38782f08681c57c6e6
Author: Jack Mordaunt <jackmordaunt.dev@gmail.com>
Date: Wed, 26 Jan 2022 00:47:23 +0800
webp: add flags to control quality
Signed-off-by: Jack Mordaunt <jackmordaunt.dev@gmail.com>
Diffstat:
| M | main.go | | | 28 | ++++++++++++++++++++-------- |
1 file changed, 20 insertions(+), 8 deletions(-)
diff --git a/main.go b/main.go
@@ -1,6 +1,7 @@
package main
import (
+ "flag"
"fmt"
"image"
"os"
@@ -21,10 +22,17 @@ func main() {
}
func run(args []string) error {
- if len(args) < 1 {
+ var (
+ quality float64
+ lossless bool
+ )
+ flag.BoolVar(&lossless, "lossless", false, "lossless quality, ignores quality flag")
+ flag.Float64Var(&quality, "quality", 1.0, "quality from [0,1]")
+ flag.Parse()
+ if len(flag.Args()) < 1 {
return fmt.Errorf("provide image to encode as webp, try megopher.png")
}
- input := args[0]
+ input := flag.Args()[0]
srcf, err := os.Open(input)
if err != nil {
return fmt.Errorf("opening input file: %w", err)
@@ -42,8 +50,6 @@ func run(args []string) error {
}
}
var (
- quality = float32(100.0)
- lossless = int32(0)
// out buffer to contain webp data.
out *byte = nil
)
@@ -55,8 +61,6 @@ func run(args []string) error {
int32(rgbaImg.Stride),
// Function pointers are generated by taking a pointer to
// a struct who's first field is that function.
- // That being said, this could be nil because we don't actually
- // invoke it in our bsearch implementation.
*(*uintptr)(unsafe.Pointer(
&struct {
f func(tls *libc.TLS, picture uintptr, rgba uintptr, rgba_stride int32) int32
@@ -64,8 +68,9 @@ func run(args []string) error {
WebPPictureImportRGBA,
},
)),
- quality,
- lossless,
+ // quality for libwebp is [0,100].
+ float32(quality*100),
+ boolToInt32(lossless),
uintptr(unsafe.Pointer(&out)),
)
if size == 0 {
@@ -79,3 +84,10 @@ func run(args []string) error {
}
return nil
}
+
+func boolToInt32(b bool) int32 {
+ if b {
+ return 1
+ }
+ return 0
+}
