Improve DjVu support

README.md

@@ -30,7 +30,6 @@ Bitcoin: 17jaxj26vFJNqQ2hEVerbBV5fpTusfqFro
 | Package | Version tested | Required for |
 | --- | --- | --- |
 | python-pymupdf | 1.14.5 | PDF support |
-| python-numpy | 1.16.2 | DjVu support |
 | python-djvulibre | 0.8.4 | DjVu support |
 
 ## Support

TODO

@@ -89,6 +89,7 @@ TODO
                 Have them save to memory
         ✓ fb2 support
             ✓ Images need to show up in their placeholders
+        ✓ djvu support
     Other:
         ✓ Define every widget in code
     Bugs:
@@ -121,10 +122,11 @@ TODO
         Goodreads API: Ratings, Read, Recommendations
         Get ISBN using python-isbnlib
         Use embedded fonts + CSS
-        txt, doc, chm, djvu support
+        txt, doc, chm, markdown support
         Include icons for filetype emblems
         Comic view modes
             Continuous paging
+            Image rotation
         Ignore a / the / numbers for sorting purposes
         ? Add only one file type if multiple are present
         ? Create emblem per filetype

lector/contentwidgets.py

@@ -106,7 +106,7 @@ class PliantQGraphicsView(QtWidgets.QGraphicsView):
 
                 elif self.filetype == 'djvu':
                     page_data = self.book.pages[page]
-                    pixmap = render_djvu_page(page_data, '/tmp')
+                    pixmap = render_djvu_page(page_data)
 
                 return pixmap
 
@@ -183,12 +183,10 @@ class PliantQGraphicsView(QtWidgets.QGraphicsView):
 
         # TODO
         # Get caching working for double page view
-        # Get caching working for DjVu files
 
         # All of these must be True
         caching_conditions = (
             not double_page_mode,
-            not self.filetype == 'djvu',
             self.main_window.settings['caching_enabled'])
 
         if False not in caching_conditions:

lector/parsers/djvu.py

@@ -17,33 +17,23 @@
 import os
 import collections
 
-import numpy
 import djvu.decode
 from PyQt5 import QtGui
 
-djvu_pixel_format = djvu.decode.PixelFormatRgbMask(0xFF0000, 0xFF00, 0xFF, bpp=32)
-djvu_pixel_format.rows_top_to_bottom = 1
-djvu_pixel_format.y_top_to_bottom = 0
-
 
 class ParseDJVU:
-    def __init__(self, filename, temp_dir, file_md5):
+    def __init__(self, filename, *args):
         self.book = None
         self.filename = filename
 
-        # Create the temporary directory where
-        # rendered pngs will be stored
-        # This may be skipped in case QImage to QPixmap conversion
-        # stops segfaulting
-        self.extract_dir = os.path.join(temp_dir, file_md5)
-        os.makedirs(self.extract_dir, exist_ok=True)
-
     def read_book(self):
         self.book = djvu.decode.Context().new_document(
             djvu.decode.FileURI(self.filename))
         self.book.decoding_job.wait()
 
     def generate_metadata(self):
+        # TODO
+        # What even is this?
         title = os.path.basename(self.filename)
         author = 'Unknown'
         year = 9999
@@ -51,7 +41,7 @@ class ParseDJVU:
         tags = []
 
         cover_page = self.book.pages[0]
-        cover = render_djvu_page(cover_page, self.extract_dir, True)
+        cover = render_djvu_page(cover_page, True)
 
         Metadata = collections.namedtuple(
             'Metadata', ['title', 'author', 'year', 'isbn', 'tags', 'cover'])
@@ -60,46 +50,49 @@ class ParseDJVU:
     def generate_content(self):
         # TODO
         # See if it's possible to generate a more involved ToC
-
         content = list(range(len(self.book.pages)))
         toc = [(1, f'Page {i + 1}', i + 1) for i in content]
 
         # Return toc, content, images_only
         return toc, content, True
 
-def render_djvu_page(page, extract_dir, for_cover=False):
 
+def render_djvu_page(page, for_cover=False):
     # TODO
     # Figure out how to calculate image stride
-    bytes_per_line = 13200
+    # and if it impacts row_alignment in the render
+    # method below
+    # bytes_per_line = 13200
 
-    # Yes, but why?
+    djvu_pixel_format = djvu.decode.PixelFormatRgbMask(
+        0xFF0000, 0xFF00, 0xFF, bpp=32)
+    djvu_pixel_format.rows_top_to_bottom = 1
+    djvu_pixel_format.y_top_to_bottom = 0
+
+    # ¯\_(ツ)_/¯
     mode = 0
 
     page_job = page.decode(wait=True)
     width, height = page_job.size
     rect = (0, 0, width, height)
-    color_buffer = numpy.zeros((height, bytes_per_line), dtype=numpy.uint32)
-    page_job.render(
-        mode, rect, rect, djvu_pixel_format,
-        row_alignment=bytes_per_line,
-        buffer=color_buffer)
-    color_buffer ^= 0xFF000000
+    output = page_job.render(
+        mode, rect, rect, djvu_pixel_format)
+        # row_alignment=bytes_per_line)
 
     imageFormat = QtGui.QImage.Format_RGB32
-    pageQImage = QtGui.QImage(color_buffer, width, height, imageFormat)
+    pageQImage = QtGui.QImage(output, width, height, imageFormat)
+
+    # Format conversion not only keeps the damn thing from
+    # segfaulting when converting from QImage to QPixmap,
+    # but it also allows for the double page mode to keep
+    # working properly. We like format conversion.
+    pageQImage = pageQImage.convertToFormat(
+        QtGui.QImage.Format_ARGB32_Premultiplied)
 
     if for_cover:
         return pageQImage
 
-    # TODO
-    # Converting from the QImage to the QPixmap directly
-    # outright segfaults sometimes.
-    # This damages caching, speed and my ego
-
-    outfile = os.path.join(extract_dir, 'temporaryPNG.png')
-    pageQImage.save(outfile)
     pixmap = QtGui.QPixmap()
-    pixmap.load(outfile)
+    pixmap.convertFromImage(pageQImage)
 
     return pixmap

lector/readers/read_epub.py

@@ -89,7 +89,7 @@ class EPUB:
                     return i
 
         # If the file isn't found
-        logger.error(filename + ' not found in ' + self.book_filename)
+        logger.warning(filename + ' not found in ' + self.book_filename)
         return False
 
     def generate_toc(self):
@@ -109,7 +109,7 @@ class EPUB:
 
             if not toc_filename:
                 if not toc_filename_alternative:
-                    logger.error('No ToC found for: ' + self.book_filename)
+                    logger.warning('No ToC found for: ' + self.book_filename)
                 else:
                     toc_filename = toc_filename_alternative
 

lector/sorter.py

@@ -62,14 +62,13 @@ else:
     print(error_string)
     logger.error(error_string)
 
-# numpy and djvu - Optional
-numpy_check = importlib.util.find_spec('numpy')
+# djvu - Optional
 djvu_check = importlib.util.find_spec('djvu.decode')
-if numpy_check and djvu_check:
+if djvu_check:
     from lector.parsers.djvu import ParseDJVU
     sorter['djvu'] = ParseDJVU
 else:
-    error_string = 'numpy / djvulibre is not installed. Will be unable to load Djvu files.'
+    error_string = 'djvulibre is not installed. Will be unable to load Djvu files.'
     print(error_string)
     logger.error(error_string)
 

lector/threaded.py

@@ -25,11 +25,17 @@ from PyQt5 import QtCore, QtGui
 from lector import sorter
 from lector import database
 
+# The following have to be separate
 try:
     from lector.parsers.pdf import render_pdf_page
 except ImportError:
     pass
 
+try:
+    from lector.parsers.djvu import render_djvu_page
+except ImportError:
+    pass
+
 logger = logging.getLogger(__name__)
 
 
@@ -165,6 +171,10 @@ class BackGroundCacheRefill(QtCore.QThread):
                 page_data = self.book.loadPage(current_page)
                 pixmap = render_pdf_page(page_data)
 
+            elif self.filetype == 'djvu':
+                page_data = self.book.pages[current_page]
+                pixmap = render_djvu_page(page_data)
+
             return pixmap
 
         remove_index = self.image_cache.index(self.remove_value)