diff --git a/removeads.py b/removeads.py
index c45ac86..9a7f3af 100755
--- a/removeads.py
+++ b/removeads.py
@@ -7,7 +7,7 @@ from datetime import datetime,timedelta,time
 import coloredlogs, logging
 from functools import cmp_to_key
 from subprocess import Popen, PIPE
-from os import read, write, lseek, pipe, set_inheritable, memfd_create, SEEK_SET, close, unlink
+from os import read, write, lseek, pipe, set_inheritable, memfd_create, SEEK_SET, close, unlink, fstat, ftruncate
 import os.path
 from io import BytesIO, TextIOWrapper
 import json
@@ -190,7 +190,7 @@ def getFormat(ffprobe, inputFile):
     logger = logging.getLogger(__name__)
         
     infd = inputFile.fileno()
-    inputFile.seek(0,0)
+    lseek(infd, 0, SEEK_SET)
     set_inheritable(infd, True)
     with Popen([ffprobe, '-loglevel', 'quiet', '-show_format', '-of', 'json', '-i', '/proc/self/fd/%d' % infd], stdout=PIPE, close_fds=False) as ffprobe:
         out, _ = ffprobe.communicate()
@@ -206,7 +206,7 @@ def getStreams(ffprobe, inputFile):
     logger = logging.getLogger(__name__)
         
     infd = inputFile.fileno()
-    inputFile.seek(0,0)
+    lseek(infd, 0, SEEK_SET)
     set_inheritable(infd, True)
     with Popen([ffprobe, '-loglevel', 'quiet', '-show_streams', '-of', 'json', '-i', '/proc/self/fd/%d' % infd], stdout=PIPE, close_fds=False) as ffprobe:
         out, _ = ffprobe.communicate()
@@ -483,10 +483,10 @@ def extractMKVPart(mkvmerge, inputFile, outputFile, begin, end):
     logger = logging.getLogger(__name__)
     
     logger.info('Extract video between I-frames at %s and %s' % (begin,end))
-    inputFile.seek(0,0)
-    outputFile.seek(0,0)
     infd = inputFile.fileno()
     outfd = outputFile.fileno()
+    lseek(infd, 0, SEEK_SET)
+    lseek(outfd, 0, SEEK_SET)
     set_inheritable(infd, True)
     set_inheritable(outfd, True)
     warnings = []
@@ -518,8 +518,9 @@ def extractMKVPart(mkvmerge, inputFile, outputFile, begin, end):
 def extractPictures(ffmpeg, inputFile, begin, nbFrames, width=640, height=480):
     logger = logging.getLogger(__name__)
         
-    inputFile.seek(0,0)
+
     infd = inputFile.fileno()
+    lseek(infd, 0, SEEK_SET)
     outfd = memfd_create('pictures', flags=0)
     set_inheritable(outfd, True)
     # PPM header
@@ -549,9 +550,9 @@ def extractPictures(ffmpeg, inputFile, begin, nbFrames, width=640, height=480):
 def extractSound(ffmpeg, inputFile, begin, outputFileName, packetDuration, subChannel=0, nbPackets=0, sampleRate=48000, nbChannels=2):
     logger = logging.getLogger(__name__)
     
-    inputFile.seek(0,0)
     outfd = memfd_create(outputFileName, flags=0)
     infd = inputFile.fileno()
+    lseek(infd, 0, SEEK_SET)
     set_inheritable(infd, True)
     set_inheritable(outfd, True)
     sound = bytes()