Commit graph

55 commits

Author SHA1 Message Date
Nico Weber
953f6c5d9b LibPDF+LibGfx: Pass jbig2-filtered data to JBIG2ImageDecoderPlugin
Except for /JBIG2Globals, which we bail out on for now. In my 1000
files, 13 use JBIG2, and of those, 2 use JBIG2Globals (0000372.pdf e.g.
page 11 and 0000857.pdf e.g. page 1), and only one (the latter) of the
two uses the same JBIG2Globals stream for more than a single image.

JBIG2ImageDecoderPlugin cannot decode the data yet, so no behavior
change, but with `#define JBIG2_DEBUG 1` at the top of that file,
it now prints segment header info for PDFs containing JBIG2 data :^)
2024-03-09 16:01:22 +01:00
Nico Weber
b1fdc33a22 LibGfx/JBIG2: Decode all segment headers
With `#define JBIG2_DEBUG 1` at the top of the file:

    % Build/lagom/bin/image --no-output \
       .../JBIG2_ConformanceData-A20180829/F01_200_TT10.jb2
    JBIG2LoadingContext: Organization: 0 (Sequential)
    JBIG2LoadingContext: Number of pages: 1
    Segment number: 0
    Segment type: 48
    Referred to segment count: 0
    Segment page association: 1
    Segment data length: 19
    Segment number: 1
    Segment type: 39
    Referred to segment count: 0
    Segment page association: 1
    Segment data length: 12666
    Segment number: 2
    Segment type: 49
    Referred to segment count: 0
    Segment page association: 1
    Segment data length: 0
    Runtime error: JBIG2ImageDecoderPlugin: Draw the rest of the owl
2024-03-09 16:01:22 +01:00
Nico Weber
177664cfae LibGfx/JBIG2: Add an initial decode_segment_header()
With `#define JBIG2_DEBUG 1` at the top of the file:

    % Build/lagom/bin/image --no-output \
        .../JBIG2_ConformanceData-A20180829/F01_200_TT10.jb2
    JBIG2LoadingContext: Organization: 0 (Sequential)
    JBIG2LoadingContext: Number of pages: 1
    Segment number: 0
    Segment type: 48
    Referred to segment count: 0
    Segment page association: 1
    Segment data length: 19
    Runtime error: JBIG2ImageDecoderPlugin: Draw the rest of the owl
2024-03-09 16:01:22 +01:00
Nico Weber
5cefcad2fe LibGfx/JBIG2: Decode the file header
Running `image` with `#define JBIG2_DEBUG 1` now prints number of pages.
2024-03-09 16:01:22 +01:00
Nico Weber
58838db445 LibGfx: Add the start of a JBIG2 loader
JBIG2 is infamous for two things:

1. It's used in xerox scanners were it falsifies scanned numbers:

https://www.dkriesel.com/en/blog/2013/0802_xerox-workcentres_are_switching_written_numbers_when_scanning

2. It was allegedly used in an iOS zero day, in a very cool way:

https://googleprojectzero.blogspot.com/2021/12/a-deep-dive-into-nso-zero-click.html

Needless to say, we need support for it in Serenity. (...because it's
used in PDF files.)

This adds all the scaffolding, but no actual implementation yet.

It's enough for `file` to print the mime type of .jb2 files, but `image`
can't do anything with the files yet.
2024-03-09 16:01:22 +01:00