Decoding reads more bytes than necessary? about hdr

[mdouchement]

Hello, I think it's because rgbe.Decode uses a bufio.NewReader with a buffer of 4096 bytes. The next image has been partially read during the decoding of the first image.
Decoder assumes that only one image is read.

Alternatively, you can use a bytes.Reader that is seekable:

package main

import (
	"bytes"
	"image"
	"io"
	"os"

	"github.com/mdouchement/hdr"
	"github.com/mdouchement/hdr/codec/rgbe"
)

func main() {
	f, err := os.Open("memorial_o876.hdr")
	check(err)
	defer f.Close()

	m, _, err := image.Decode(f)
	check(err)

	img := m.(hdr.Image)

	var buf bytes.Buffer
	err = rgbe.Encode(&buf, img)
	check(err)

	n := buf.Len()

	err = rgbe.Encode(&buf, img)
	check(err)

	r := bytes.NewReader(buf.Bytes())

	_, err = rgbe.Decode(r)
	check(err)

	_, err = r.Seek(int64(n), io.SeekStart) // Set the start of the second image
	check(err)

	_, err = rgbe.Decode(r)
	check(err)
}

func check(err error) {
	if err != nil {
		panic(err)
	}
}

[NicolasBuecher]

Oh god, I didn't expect a response so fast and so complete.
So this a feature, not a bug! 😄

That was how I intended to go through the issue, but I couldn't sleep without understanding why I had to do that.

Thank you very much for your time!