libervia-backend/libervia/backend/plugins/plugin_xep_0264.py
Goffi 33f9554b94 plugin XEP-0264: Convert image to RGB if there is transparency:
JPEG doesn't support transparency, which was resulting in exception if a preview of an
image with transparency was made. This is now checked, and the image is converted if
necessary.
2026-07-09 17:13:37 +02:00

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#!/usr/bin/env python3
# SàT plugin for managing xep-0264
# Copyright (C) 2009-2026 Jérôme Poisson (goffi@goffi.org)
# Copyright (C) 2014 Emmanuel Gil Peyrot (linkmauve@linkmauve.fr)
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Affero General Public License for more details.
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
from typing import Literal
from twisted.words.protocols.jabber.xmlstream import XMPPHandler
from libervia.backend.core.i18n import _
from libervia.backend.core.constants import Const as C
from libervia.backend.core.log import getLogger
log = getLogger(__name__)
from twisted.internet import defer, threads
from zope.interface import implementer
from tx_xmpp import disco, itx_xmpp
from libervia.backend.core import exceptions
import hashlib
try:
from PIL import Image, ImageOps
except:
raise exceptions.MissingModule(
"Missing module pillow, please download/install it from https://python-pillow.github.io"
)
#  cf. https://stackoverflow.com/a/23575424
from PIL import ImageFile
ImageFile.LOAD_TRUNCATED_IMAGES = True
MIME_TYPE = "image/jpeg"
SAVE_FORMAT = "JPEG" # (cf. Pillow documentation)
NS_THUMBS = "urn:xmpp:thumbs:1"
PLUGIN_INFO = {
C.PI_NAME: "XEP-0264",
C.PI_IMPORT_NAME: "XEP-0264",
C.PI_TYPE: "XEP",
C.PI_MODES: C.PLUG_MODE_BOTH,
C.PI_PROTOCOLS: ["XEP-0264"],
C.PI_DEPENDENCIES: ["XEP-0234"],
C.PI_MAIN: "XEP_0264",
C.PI_HANDLER: "yes",
C.PI_DESCRIPTION: _("""Thumbnails handling"""),
}
class XEP_0264(object):
SIZE_SMALL = (320, 320)
SIZE_MEDIUM = (640, 640)
SIZE_BIG = (1280, 1280)
SIZE_FULL_SCREEN = (2560, 2560)
# FIXME: SIZE_FULL_SCREEN is currently discarded as the resulting files are too big
# for BoB
# TODO: use an other mechanism than BoB for bigger files
SIZES = (SIZE_SMALL, SIZE_MEDIUM, SIZE_BIG)
def __init__(self, host) -> None:
log.info(_("Plugin XEP_0264 initialization"))
self.host = host
host.trigger.add("XEP-0234_buildFileElement", self._add_file_thumbnails)
host.trigger.add("XEP-0234_parseFileElement", self._get_file_thumbnails)
def get_handler(self, client) -> "XEP_0264_handler":
return XEP_0264_handler()
## triggers ##
def _add_file_thumbnails(self, client, file_elt, extra_args) -> Literal[True]:
try:
thumbnails = extra_args["extra"][C.KEY_THUMBNAILS]
except KeyError:
return True
for thumbnail in thumbnails:
thumbnail_elt = file_elt.addElement((NS_THUMBS, "thumbnail"))
thumbnail_elt["uri"] = "cid:" + thumbnail["id"]
thumbnail_elt["media-type"] = MIME_TYPE
width, height = thumbnail["size"]
thumbnail_elt["width"] = str(width)
thumbnail_elt["height"] = str(height)
return True
def _get_file_thumbnails(self, client, file_elt, file_data) -> Literal[True]:
thumbnails = []
for thumbnail_elt in file_elt.elements(NS_THUMBS, "thumbnail"):
uri = thumbnail_elt["uri"]
if uri.startswith("cid:"):
thumbnail = {"id": uri[4:]}
width = thumbnail_elt.getAttribute("width")
height = thumbnail_elt.getAttribute("height")
if width and height:
try:
thumbnail["size"] = (int(width), int(height))
except ValueError:
pass
try:
thumbnail["mime_type"] = thumbnail_elt["media-type"]
except KeyError:
pass
thumbnails.append(thumbnail)
if thumbnails:
# we want thumbnails ordered from smallest to biggest
thumbnails.sort(key=lambda t: t.get("size", (0, 0)))
file_data.setdefault("extra", {})[C.KEY_THUMBNAILS] = thumbnails
return True
## thumbnails generation ##
def get_thumb_id(self, image_uid, size):
"""return an ID unique for image/size combination
@param image_uid(unicode): unique id of the image
can be a hash
@param size(tuple(int)): requested size of thumbnail
@return (unicode): unique id for this image/size
"""
return hashlib.sha256(repr((image_uid, size)).encode()).hexdigest()
def _blocking_gen_thumb(
self,
source_path: str,
size: tuple[int, int] | None = None,
max_age: int | None = None,
image_uid: str | None = None,
fix_orientation: bool = True,
) -> tuple[tuple[int, int], str]:
"""Generate a thumbnail for image
This is a blocking method and must be executed in a thread
params are the same as for [generate_thumbnail]
@raise exception.DataError: Can't generate thumbnail.
"""
if size is None:
size = self.SIZE_SMALL
try:
img = Image.open(source_path)
except IOError as e:
raise exceptions.DataError("Can't open image") from e
img.thumbnail(size)
if fix_orientation:
img = ImageOps.exif_transpose(img)
uid = self.get_thumb_id(image_uid or source_path, size)
with self.host.common_cache.cache_data(
PLUGIN_INFO[C.PI_IMPORT_NAME], uid, MIME_TYPE, max_age
) as f:
# XXX: JPEG is used and doesn't support transparency, we need to convert
# convert to RGB. We may want to change that in the future if another format
# is used.
if img.mode in ("RGBA", "LA", "P"):
img = img.convert("RGB")
img.save(f, SAVE_FORMAT)
if fix_orientation:
log.debug(f"fixed orientation for {f.name}")
return img.size, uid
async def generate_thumbnail(
self,
source_path: str,
size: int | None = None,
max_age: int | None = None,
image_uid: str | None = None,
fix_orientation: bool = True,
) -> tuple[tuple[int, int], str]:
"""Generate a thumbnail of image
@param source_path: absolute path to source image
@param size: max size of the thumbnail
can be one of self.SIZE_*
None to use default value (i.e. self.SIZE_SMALL)
@param max_age: same as for [memory.cache.Cache.cache_data]
@param image_uid: unique ID to identify the image
use hash whenever possible
if None, source_path will be used
@param fix_orientation: if True, fix orientation using EXIF data
@return: tuple with:
- size of the thumbnail
- unique Id of the thumbnail
"""
return await threads.deferToThread(
self._blocking_gen_thumb,
source_path,
size,
max_age,
image_uid=image_uid,
fix_orientation=fix_orientation,
)
@implementer(itx_xmpp.IDisco)
class XEP_0264_handler(XMPPHandler):
def getDiscoInfo(self, requestor, target, nodeIdentifier=""):
return [disco.DiscoFeature(NS_THUMBS)]
def getDiscoItems(self, requestor, target, nodeIdentifier=""):
return []