mirror of
https://github.com/superseriousbusiness/gotosocial
synced 2024-12-23 15:08:32 +01:00
94e87610c4
* add back exif-terminator and use only for jpeg,png,webp * fix arguments passed to terminateExif() * pull in latest exif-terminator * fix test * update processed img --------- Co-authored-by: tobi <tobi.smethurst@protonmail.com>
86 lines
2.3 KiB
Go
86 lines
2.3 KiB
Go
/*
|
|
exif-terminator
|
|
Copyright (C) 2022 SuperSeriousBusiness admin@gotosocial.org
|
|
|
|
This program is free software: you can redistribute it and/or modify
|
|
it under the terms of the GNU Affero General Public License as published by
|
|
the Free Software Foundation, either version 3 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU Affero General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Affero General Public License
|
|
along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
package terminator
|
|
|
|
import (
|
|
"io"
|
|
|
|
pngstructure "github.com/superseriousbusiness/go-png-image-structure/v2"
|
|
)
|
|
|
|
type pngVisitor struct {
|
|
ps *pngstructure.PngSplitter
|
|
writer io.Writer
|
|
lastWrittenChunk int
|
|
}
|
|
|
|
func (v *pngVisitor) split(data []byte, atEOF bool) (int, []byte, error) {
|
|
// execute the ps split function to read in data
|
|
advance, token, err := v.ps.Split(data, atEOF)
|
|
if err != nil {
|
|
return advance, token, err
|
|
}
|
|
|
|
// if we haven't written anything at all yet, then
|
|
// write the png header back into the writer first
|
|
if v.lastWrittenChunk == -1 {
|
|
if _, err := v.writer.Write(pngstructure.PngSignature[:]); err != nil {
|
|
return advance, token, err
|
|
}
|
|
}
|
|
|
|
// Check if the splitter now has
|
|
// any new chunks in it for us.
|
|
chunkSlice, err := v.ps.Chunks()
|
|
if err != nil {
|
|
return advance, token, err
|
|
}
|
|
|
|
// Write each chunk by passing it
|
|
// through our custom write func,
|
|
// which strips out exif and fixes
|
|
// the CRC of each chunk.
|
|
chunks := chunkSlice.Chunks()
|
|
for i := v.lastWrittenChunk + 1; i < len(chunks); i++ {
|
|
chunk := chunks[i]
|
|
|
|
if chunk.Type == pngstructure.EXifChunkType {
|
|
// Finally, some exif data! Terminate it!!
|
|
if err := terminateEXIF(chunkSlice); err != nil {
|
|
return advance, token, err
|
|
}
|
|
|
|
// Update chunk crc.
|
|
chunk.UpdateCrc32()
|
|
}
|
|
|
|
// Write this new chunk.
|
|
if _, err := chunk.WriteTo(v.writer); err != nil {
|
|
return advance, token, err
|
|
}
|
|
v.lastWrittenChunk = i
|
|
|
|
// Zero data; here you
|
|
// go garbage collector.
|
|
chunk.Data = nil
|
|
}
|
|
|
|
return advance, token, err
|
|
}
|