Python script to inject the EOI marker into panoramic photos created by the S7 camera. In addition the script allows to dump the Samsung specific data that is added to the image

fix_eoi.py

#!/usr/bin/python

# The Samsung trailer format is based on the implementation from ExifTool
# http://www.sno.phy.queensu.ca/~phil/exiftool/

import mmap
import struct
import os
import sys

if (len(sys.argv) < 2) or (len(sys.argv) > 3):
	print("Usage: fix_eoi.py <filename> [dump]")
	exit()

file = sys.argv[1]

if len(sys.argv) < 3:
	dump = 0
elif sys.argv[2] == "dump":
	dump = 1
else:
	print("Invalid argument")
	print("Usage: fix_eoi.py <filename> [dump]")
	exit()

(file_name, file_ext) = os.path.splitext(file)

with open(file, 'rb') as fh:
	m = mmap.mmap(fh.fileno(), 0, access=mmap.ACCESS_READ)
	b = bytearray(m)
	
	trailer_tail = b[-4:]
	
	if trailer_tail != 'SEFT':
		print("No valid Samsung trailer found")
		exit()
	else:
		print("Found SEFT")
	
	length = struct.unpack_from("<I",b[-8:-4])[0]	
	trailer = b[-(8+length):]
	
	endPos = len(b)
	dirPos = endPos-(8+length)
	
	if trailer[0:4] != 'SEFH':
		print("No valid Samsung trailer found")
		exit()
	else:
		print("Found SEFH")
	
	version = struct.unpack_from("<I",trailer[4:8])[0]
	if version != 101:
		print("Unknown Samsung trailer version")
		exit()
	
	count = struct.unpack_from("<I",trailer[8:12])[0]
	
	firstBlock = 0
	is_pano = 0
	
	for index in range(0, count):
		entry = 12 + 12 * index;
		
		type = struct.unpack_from("<H",trailer[entry+2:entry+4])[0]
		noff = struct.unpack_from("<I",trailer[entry+4:entry+8])[0]
		size = struct.unpack_from("<I",trailer[entry+8:entry+12])[0]
		
		if firstBlock < noff:
			firstBlock = noff
		
		entryPos = dirPos - noff
		entryLen = size
		
		data = b[entryPos:entryPos+entryLen]
		
		# Validate as the type has to match the SEFH/SEFT entry type
		entry_type = struct.unpack_from("<H",data[2:4])[0]
		if type != entry_type:
			print("Missmatch detected. Aborting!")
			exit()
			
		entry_offset = struct.unpack_from("<I",data[4:8])[0]
		entry_name = data[8:8+entry_offset].decode("utf-8") 
		
		if entry_name == "Panorama_Shot_Info":
			is_pano = 1
		
		entry_data = data[8+entry_offset:]
		
		if dump:
			print("Dumping: %s" % entry_name)
			with open(file_name + '_' + entry_name, 'wb') as f:
				f.write(entry_data)

	if not is_pano:
		print "No Panorama info found"
		exit()
	
	dataPos = dirPos - firstBlock
	dirLen = endPos - dataPos
	
	eoi = struct.unpack_from(">H",b[dataPos-2:dataPos])[0]
	if eoi == 0xffd9:
		print("Found EOI")
		exit()
	else:
		print("Inserting EOI")
		with open(file_name + '_pano' + file_ext, 'wb') as f:
				f.write(b[0:dataPos])
				f.write(bytearray(b'\xff\xd9'))
				f.write(b[dataPos:])
	

@O-Sullivan
Thanks, it works!

Great work! Thanks!

This is wonderful thank you, it's helping me import my panoramas into Shotwell on Linux. I'm wondering, if there is this extra MP4 track inside the JPEG (I didn't even know that was possible) and you can "dump" it to a separate file, could there be an option to exclude it from the corrected JPEG? I don't need that track and it's about a third of the whole file size.

@nrrkeene
The following command (if you have jpegtran) will strip the extra junk (after the file has been corrected):
jpegtran -copy all -optimize fixed.jpg > fixed_stripped.jpg

Added a fork that works w. S8+, plus some decorations for batch friendliness.

I made a rust version which can strip the files of the videos and reduce the size in about half. This version merely makes the file a valid JPEG file but the video remains in there. I also made some binaries if somebody is interested: https://github.com/frapa/sampan