1. Victor Stinner
  2. hachoir


hachoir / hachoir-tools / hachoir-strip

haypo f6c98f9 
jm 8bfaf70 

haypo af62d52 
jm 8bfaf70 
haypo 6e4ac19 
jm 8bfaf70 

haypo bcaff00 
jm 8bfaf70 

haypo bcaff00 

jm 8bfaf70 

haypo f5debec 

haypo 410acea 
jm 8bfaf70 

haypo bcaff00 

jm 8bfaf70 

haypo bcaff00 

haypo 15e92f6 
haypo bcaff00 

jm 8bfaf70 

haypo bcaff00 
jm 8bfaf70 

haypo bcaff00 
jm 8bfaf70 

haypo bcaff00 

jm 8bfaf70 

haypo bcaff00 

jm 8bfaf70 

Binary striper: remove metadata, producer information, useless padding, etc.
from binary files.

Author: Victor Stinner
Creation: 17 september 2006

from hachoir_core.field import MissingField
from hachoir_core.cmd_line import unicodeFilename
from hachoir_editor import (createEditor,
    NewFieldSet, EditableInteger, EditableBytes)
from hachoir_core.stream import FileOutputStream, StringOutputStream
from hachoir_core.tools import humanFilesize, makePrintable
from hachoir_core.i18n import _, getTerminalCharset
from hachoir_parser import createParser
from optparse import OptionGroup, OptionParser
import hachoir_core
import sys

# File formats
from hachoir_parser.archive import TarFile
from hachoir_parser.audio import AuFile
from hachoir_parser.image import PngFile, JpegFile
from hachoir_parser.container import RiffFile
from hachoir_parser.audio import MpegAudioFile

# Constants
__version__ = "0.1"
WEBSITE = "%s/wiki/hachoir-strip" % hachoir_core.WEBSITE

# Strip what?
STRIP_USELESS  = 0x01   # Useless padding, useless duplicate information, etc.
STRIP_METADATA = 0x02   # Timestamp, author, producter, comment, etc.
STRIP_INDEX    = 0x04   # Index in video

class BasicStripper:
    def __init__(self, editor, level, verbose=False):
        self.editor = editor
        self.level = level
        self.verbose = verbose
        self._is_dirty = False
        self._removed_bytes = 0

    def __call__(self):
        self.stripped_bytes = self.strip()
        if self.stripped_bytes:
            self._is_dirty = True
        return self._is_dirty

    def info(self, message):
        if self.verbose:
            print message

    def strip(self):
        Strip input editor. Returns number of remove bits.
        raise NotImplementedError()

    def removeField(self, field, editor=None):
        if not editor:
            editor = self.editor
        self.info("Remove field %s" % field.path)
        size = field.size
        del editor[field.name]
        return size

    def removeFields(self, fields, editor=None):
        if not editor:
            editor = self.editor
        return sum(self.removeField(field, editor) for field in fields)

class CheckStripper(BasicStripper):
    def checkField(self, field):
        Check if a field of the root have to be removed or not.
        Returns boolean.
        raise NotImplementedError()

    def strip(self):
        fields = (field for field in self.editor if self.checkField(field))
        return self.removeFields(fields)

class PngStripper(CheckStripper):
    def checkField(self, field):
        if self.level & STRIP_METADATA:
            name = field.name
            if name.startswith("text["):
                return True
            if name == "time":
                return True
        return False

class JpegStripper(CheckStripper):
    def checkField(self, field):
        if self.level & STRIP_METADATA:
            if field.name.startswith("comment"):
                return True
            return field.name in ("photoshop", "exif", "adobe")
        return False

class MpegAudioStripper(CheckStripper):
    def checkField(self, field):
        if self.level & STRIP_METADATA:
            return field.name in ("id3v1", "id3v2")
        return False

class AuStripper(BasicStripper):
    def strip(self):
        if self.level & STRIP_METADATA and "info" in self.editor:
            size = self.editor["info"].size
            self.editor["data_ofs"].value -= (size // 8)
            return self.removeField(self.editor["info"])
            return 0

class RiffStripper(BasicStripper):
    def stripSub(self, editor, names):
        remove = []
        total = 0
        for field in editor:
            if field.name in names:
                tag = field["tag"].value
            except MissingField:
            if self.level & STRIP_USELESS and tag in "JUNK":
            if tag == "LIST" and field.name != "movie":
                # Strip a chunk list
                size = self.stripSub(field, names)
                if size:
                    # Update chunk list size
                    field["size"].value -= (size // 8)
                total += size
        total += self.removeFields(remove, editor)
        return total

    def strip(self):
        names = []
        if self.level & STRIP_USELESS:
        if self.level & STRIP_METADATA:
        if self.level & STRIP_INDEX:
            if "/headers/avi_hdr/has_index" in self.editor:
                self.editor["/headers/avi_hdr/has_index"].value = False
        size = self.stripSub(self.editor, names)
        if size:
            # Update file size field
            self.editor["filesize"].value -= (size // 8)
        return size

class MpegAudioStripper(CheckStripper):
    def checkField(self, field):
        if self.level & STRIP_METADATA:
            return field.name in ("id3v1", "id3v2")
        return False

def usage():
    print "Usage: %s filename" % sys.argv[0]

class TarStripper(BasicStripper):
    def strip(self):
        for file in self.editor.array("file"):

    def fixChecksum(self, file):
        file["check_sum"].value = " " * 8
        stream = StringOutputStream()
        data = stream.readBytes(0, 512)
        checksum = sum( ord(character) for character in data )
        file["check_sum"].value = ("0%o\0" % checksum).ljust(8, " ")

    def stripFile(self, file):
        empty32 = "\0" * 32
        uid = "0000000\0"
        file["uid"].value = uid
        file["gid"].value = uid
        file["mtime"].value = "00000000000\0"
        file["uname"].value = empty32
        file["gname"].value = empty32
        self._is_dirty = True

strippers = {
    AuFile: AuStripper,
    RiffFile: RiffStripper,
    PngFile: PngStripper,
    JpegFile: JpegStripper,
    MpegAudioFile: MpegAudioStripper,
    TarFile: TarStripper,

def stripEditor(editor, filename, level, verbose):
    cls = editor.input.__class__
        stripper_cls = strippers[cls]
    except KeyError:
        print "Don't have stripper for file type: %s" % editor.description
        return False
    stripper = stripper_cls(editor, level, verbose)

    if stripper():
        filename, realname = unicodeFilename(filename), filename
        output = FileOutputStream(filename, real_filename=realname)
        size = stripper.stripped_bytes
        if size:
            percent = "%.1f%%" % (float(size) * 100 / editor.input.size)
            if size%8 and size < 128:
                print _("Remove %u.%u bytes (%s)") \
                    % (size//8, size%8, percent)
                print _("Remove %s (%s)") % (humanFilesize(size//8), percent)
        print _("Save new file into %s") % \
            makePrintable(filename, getTerminalCharset(), to_unicode=True)
        print _("Stripper doesn't touch the file")
    return True

def displayVersion(*args):
    print _("Hachoir strip version %s") % __version__
    print _("Hachoir library version %s") % hachoir_core.__version__
    print _("Website: %s") % WEBSITE

def parseOptions():
    parser = OptionParser(usage="%prog [options] filename")

    common = OptionGroup(parser, "Hachoir strip")
    common.add_option("--strip", help=_("Data types to remove: useless, metadata, index (default: all). Use comma to specify two or more."),
        type="str", action="store", default="metadata, useless, index")
    common.add_option("--quiet", help=_("Be quiet"),
        action="store_true", default=False)
    common.add_option("--version", help=_("Display version and exit"),
        action="callback", callback=displayVersion)

    values, arguments = parser.parse_args()
    if not arguments:
    return values, arguments

def main():
    # Parse arguments and read filenames
    values, filenames = parseOptions()
    level = 0
    for item in values.strip.split(","):
        item = item.strip()
        if item == "useless":
            level |= STRIP_USELESS
        elif item == "metadata":
            level |= STRIP_METADATA
        elif item == "index":
            level |= STRIP_INDEX
    if not level:
        print _("Nothing to do, exit")
    ok = True
    charset = getTerminalCharset()
    for filename in filenames:
        filename, real_filename = unicodeFilename(filename), filename
        print "[+]", (_("Process file %s") % filename)
        parser = createParser(filename, real_filename=real_filename)
        if parser:
            editor = createEditor(parser)
            ok &= stripEditor(editor, real_filename+".new", level, not(values.quiet))
            ok = False
    if ok:
if __name__ == "__main__":