Created
August 28, 2016 14:58
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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
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#!/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:]) | |
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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