diff options
Diffstat (limited to '.venv/lib/python3.12/site-packages/pypdf/generic/_image_inline.py')
| -rw-r--r-- | .venv/lib/python3.12/site-packages/pypdf/generic/_image_inline.py | 235 |
1 files changed, 235 insertions, 0 deletions
diff --git a/.venv/lib/python3.12/site-packages/pypdf/generic/_image_inline.py b/.venv/lib/python3.12/site-packages/pypdf/generic/_image_inline.py new file mode 100644 index 00000000..41826ac3 --- /dev/null +++ b/.venv/lib/python3.12/site-packages/pypdf/generic/_image_inline.py @@ -0,0 +1,235 @@ +# Copyright (c) 2024, pypdf contributors +# All rights reserved. +# +# Redistribution and use in source and binary forms, with or without +# modification, are permitted provided that the following conditions are +# met: +# +# * Redistributions of source code must retain the above copyright notice, +# this list of conditions and the following disclaimer. +# * Redistributions in binary form must reproduce the above copyright notice, +# this list of conditions and the following disclaimer in the documentation +# and/or other materials provided with the distribution. +# * The name of the author may not be used to endorse or promote products +# derived from this software without specific prior written permission. +# +# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" +# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE +# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR +# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF +# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS +# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN +# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) +# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE +# POSSIBILITY OF SUCH DAMAGE. + +import logging +from io import BytesIO + +from .._utils import ( + WHITESPACES, + StreamType, + read_non_whitespace, +) +from ..errors import PdfReadError + +logger = logging.getLogger(__name__) + +BUFFER_SIZE = 8192 + + +def extract_inline_AHx(stream: StreamType) -> bytes: + """ + Extract HexEncoded Stream from Inline Image. + the stream will be moved onto the EI + """ + data_out: bytes = b"" + # Read data until delimiter > and EI as backup + # ignoring backup. + while True: + data_buffered = read_non_whitespace(stream) + stream.read(BUFFER_SIZE) + if not data_buffered: + raise PdfReadError("Unexpected end of stream") + pos_tok = data_buffered.find(b">") + if pos_tok >= 0: # found > + data_out += data_buffered[: (pos_tok + 1)] + stream.seek(-len(data_buffered) + pos_tok + 1, 1) + break + pos_ei = data_buffered.find(b"EI") + if pos_ei >= 0: # found EI + stream.seek(-len(data_buffered) + pos_ei - 1, 1) + c = stream.read(1) + while c in WHITESPACES: + stream.seek(-2, 1) + c = stream.read(1) + pos_ei -= 1 + data_out += data_buffered[:pos_ei] + break + elif len(data_buffered) == 2: + data_out += data_buffered + raise PdfReadError("Unexpected end of stream") + else: # > nor EI found + data_out += data_buffered[:-2] + stream.seek(-2, 1) + + ei_tok = read_non_whitespace(stream) + ei_tok += stream.read(2) + stream.seek(-3, 1) + if ei_tok[0:2] != b"EI" or not (ei_tok[2:3] == b"" or ei_tok[2:3] in WHITESPACES): + raise PdfReadError("EI stream not found") + return data_out + + +def extract_inline_A85(stream: StreamType) -> bytes: + """ + Extract A85 Stream from Inline Image. + the stream will be moved onto the EI + """ + data_out: bytes = b"" + # Read data up to delimiter ~> + # see §3.3.2 from PDF ref 1.7 + while True: + data_buffered = read_non_whitespace(stream) + stream.read(BUFFER_SIZE) + if not data_buffered: + raise PdfReadError("Unexpected end of stream") + pos_tok = data_buffered.find(b"~>") + if pos_tok >= 0: # found! + data_out += data_buffered[: pos_tok + 2] + stream.seek(-len(data_buffered) + pos_tok + 2, 1) + break + elif len(data_buffered) == 2: # end of buffer + data_out += data_buffered + raise PdfReadError("Unexpected end of stream") + data_out += data_buffered[ + :-2 + ] # back by one char in case of in the middle of ~> + stream.seek(-2, 1) + + ei_tok = read_non_whitespace(stream) + ei_tok += stream.read(2) + stream.seek(-3, 1) + if ei_tok[0:2] != b"EI" or not (ei_tok[2:3] == b"" or ei_tok[2:3] in WHITESPACES): + raise PdfReadError("EI stream not found") + return data_out + + +def extract_inline_RL(stream: StreamType) -> bytes: + """ + Extract RL Stream from Inline Image. + the stream will be moved onto the EI + """ + data_out: bytes = b"" + # Read data up to delimiter ~> + # see §3.3.4 from PDF ref 1.7 + while True: + data_buffered = stream.read(BUFFER_SIZE) + if not data_buffered: + raise PdfReadError("Unexpected end of stream") + pos_tok = data_buffered.find(b"\x80") + if pos_tok >= 0: # found + data_out += data_buffered[: pos_tok + 1] + stream.seek(-len(data_buffered) + pos_tok + 1, 1) + break + data_out += data_buffered + + ei_tok = read_non_whitespace(stream) + ei_tok += stream.read(2) + stream.seek(-3, 1) + if ei_tok[0:2] != b"EI" or not (ei_tok[2:3] == b"" or ei_tok[2:3] in WHITESPACES): + raise PdfReadError("EI stream not found") + return data_out + + +def extract_inline_DCT(stream: StreamType) -> bytes: + """ + Extract DCT (JPEG) Stream from Inline Image. + the stream will be moved onto the EI + """ + data_out: bytes = b"" + # Read Blocks of data (ID/Size/data) up to ID=FF/D9 + # see https://www.digicamsoft.com/itu/itu-t81-36.html + notfirst = False + while True: + c = stream.read(1) + if notfirst or (c == b"\xff"): + data_out += c + if c != b"\xff": + continue + else: + notfirst = True + c = stream.read(1) + data_out += c + if c == b"\xff": + stream.seek(-1, 1) # pragma: no cover + elif c == b"\x00": # stuffing + pass + elif c == b"\xd9": # end + break + elif c in ( + b"\xc0\xc1\xc2\xc3\xc4\xc5\xc6\xc7\xc9\xca\xcb\xcc\xcd\xce\xcf" + b"\xda\xdb\xdc\xdd\xde\xdf" + b"\xe0\xe1\xe2\xe3\xe4\xe5\xe6\xe7\xe8\xe9\xea\xeb\xec\xed\xee\xef\xfe" + ): + c = stream.read(2) + data_out += c + sz = c[0] * 256 + c[1] + data_out += stream.read(sz - 2) + # else: pass + + ei_tok = read_non_whitespace(stream) + ei_tok += stream.read(2) + stream.seek(-3, 1) + if ei_tok[0:2] != b"EI" or not (ei_tok[2:3] == b"" or ei_tok[2:3] in WHITESPACES): + raise PdfReadError("EI stream not found") + return data_out + + +def extract_inline_default(stream: StreamType) -> bytes: + """ + Legacy method + used by default + """ + stream_out = BytesIO() + # Read the inline image, while checking for EI (End Image) operator. + while True: + data_buffered = stream.read(BUFFER_SIZE) + if not data_buffered: + raise PdfReadError("Unexpected end of stream") + pos_ei = data_buffered.find( + b"E" + ) # we can not look straight for "EI" because it may not have been loaded in the buffer + + if pos_ei == -1: + stream_out.write(data_buffered) + else: + # Write out everything including E (the one from EI to be removed). + stream_out.write(data_buffered[0 : pos_ei + 1]) + sav_pos_ei = stream_out.tell() - 1 + # Seek back in the stream to read the E next. + stream.seek(pos_ei + 1 - len(data_buffered), 1) + saved_pos = stream.tell() + # Check for End Image + tok2 = stream.read(1) # I of "EI" + if tok2 != b"I": + stream.seek(saved_pos, 0) + continue + tok3 = stream.read(1) # possible space after "EI" + if tok3 not in WHITESPACES: + stream.seek(saved_pos, 0) + continue + while tok3 in WHITESPACES: + tok3 = stream.read(1) + if data_buffered[pos_ei - 1 : pos_ei] not in WHITESPACES and tok3 not in { + b"Q", + b"E", + }: # for Q ou EMC + stream.seek(saved_pos, 0) + continue + # Data contains [\s]EI[\s](Q|EMC): 4 chars are sufficients + # remove E(I) wrongly inserted earlier + stream_out.truncate(sav_pos_ei) + break + + return stream_out.getvalue() |