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authorLibravatar tobi <31960611+tsmethurst@users.noreply.github.com>2025-03-02 15:44:02 +0100
committerLibravatar GitHub <noreply@github.com>2025-03-02 15:44:02 +0100
commitd8bb1c391b06050d0cbde554d7ba2366384f2c7d (patch)
tree55c47be446ebbc1213c1ab4de0482430f18cdd14 /vendor/codeberg.org/superseriousbusiness/go-png-image-structure/v2/chunk_decoder.go
parent[chore] github.com/superseriousbusiness/httpsig -> codeberg.org/superseriousb... (diff)
downloadgotosocial-d8bb1c391b06050d0cbde554d7ba2366384f2c7d.tar.xz
[chore] Update exif terminator version with codeberg libraries (#3855)
Diffstat (limited to 'vendor/codeberg.org/superseriousbusiness/go-png-image-structure/v2/chunk_decoder.go')
-rw-r--r--vendor/codeberg.org/superseriousbusiness/go-png-image-structure/v2/chunk_decoder.go81
1 files changed, 81 insertions, 0 deletions
diff --git a/vendor/codeberg.org/superseriousbusiness/go-png-image-structure/v2/chunk_decoder.go b/vendor/codeberg.org/superseriousbusiness/go-png-image-structure/v2/chunk_decoder.go
new file mode 100644
index 000000000..518bc91ad
--- /dev/null
+++ b/vendor/codeberg.org/superseriousbusiness/go-png-image-structure/v2/chunk_decoder.go
@@ -0,0 +1,81 @@
+package pngstructure
+
+import (
+ "bytes"
+ "fmt"
+
+ "encoding/binary"
+)
+
+type ChunkDecoder struct {
+}
+
+func NewChunkDecoder() *ChunkDecoder {
+ return new(ChunkDecoder)
+}
+
+func (cd *ChunkDecoder) Decode(c *Chunk) (decoded interface{}, err error) {
+ switch c.Type {
+ case "IHDR":
+ return cd.decodeIHDR(c)
+ }
+
+ // We don't decode this type.
+ return nil, nil
+}
+
+type ChunkIHDR struct {
+ Width uint32
+ Height uint32
+ BitDepth uint8
+ ColorType uint8
+ CompressionMethod uint8
+ FilterMethod uint8
+ InterlaceMethod uint8
+}
+
+func (ihdr *ChunkIHDR) String() string {
+ return fmt.Sprintf("IHDR<WIDTH=(%d) HEIGHT=(%d) DEPTH=(%d) COLOR-TYPE=(%d) COMP-METHOD=(%d) FILTER-METHOD=(%d) INTRLC-METHOD=(%d)>",
+ ihdr.Width, ihdr.Height, ihdr.BitDepth, ihdr.ColorType, ihdr.CompressionMethod, ihdr.FilterMethod, ihdr.InterlaceMethod,
+ )
+}
+
+func (cd *ChunkDecoder) decodeIHDR(c *Chunk) (*ChunkIHDR, error) {
+ var (
+ b = bytes.NewBuffer(c.Data)
+ ihdr = new(ChunkIHDR)
+ readf = func(data interface{}) error {
+ return binary.Read(b, binary.BigEndian, data)
+ }
+ )
+
+ if err := readf(&ihdr.Width); err != nil {
+ return nil, err
+ }
+
+ if err := readf(&ihdr.Height); err != nil {
+ return nil, err
+ }
+
+ if err := readf(&ihdr.BitDepth); err != nil {
+ return nil, err
+ }
+
+ if err := readf(&ihdr.ColorType); err != nil {
+ return nil, err
+ }
+
+ if err := readf(&ihdr.CompressionMethod); err != nil {
+ return nil, err
+ }
+
+ if err := readf(&ihdr.FilterMethod); err != nil {
+ return nil, err
+ }
+
+ if err := readf(&ihdr.InterlaceMethod); err != nil {
+ return nil, err
+ }
+
+ return ihdr, nil
+}