A fork of https://github.com/crosspoint-reader/crosspoint-reader
chore: drop JPEGDEC patch in favour of upstream fix (#1465)
## Summary
The progressive JPEG fixes (AC table skip, MCU_SKIP guard) from PR #1136
have been fixed upstream in bitbank2/JPEGDEC@8628297. Pin to that commit
and remove the pre-build patch script.
## Additional Context
Tested on Strange Pictures epub
---
### AI Usage
While CrossPoint doesn't have restrictions on AI tools in contributing,
please be transparent about their usage as it
helps set the right context for reviewers.
Did you use AI tools to help write this code? _**< PARTIALLY >**_
authored by
martin brook
and committed by
GitHub
b898d53f
c656673b
+1
-119
+1
-2
platformio.ini
+1
-2
platformio.ini
···
50
50
extra_scripts =
51
51
pre:scripts/build_html.py
52
52
pre:scripts/gen_i18n.py
53
-
pre:scripts/patch_jpegdec.py
54
53
pre:scripts/git_branch.py
55
54
56
55
; Libraries
···
62
61
bblanchon/ArduinoJson @ 7.4.2
63
62
ricmoo/QRCode @ 0.0.1
64
63
bitbank2/PNGdec @ ^1.0.0
65
-
bitbank2/JPEGDEC @ ^1.8.0
64
+
https://github.com/bitbank2/JPEGDEC.git#86282979224c8a32fd51e091ed5a35b0c699a52b
66
65
links2004/WebSockets @ 2.7.3
67
66
68
67
[env:default]
-117
scripts/patch_jpegdec.py
-117
scripts/patch_jpegdec.py
···
1
-
"""
2
-
PlatformIO pre-build script: patch JPEGDEC library for progressive JPEG support.
3
-
4
-
Two patches are applied:
5
-
6
-
1. JPEGMakeHuffTables: Skip AC Huffman table construction for progressive JPEGs.
7
-
JPEGDEC 1.8.x fails to open progressive JPEGs because JPEGMakeHuffTables()
8
-
cannot build AC tables with 11+-bit codes (the "slow tables" path is disabled).
9
-
Since progressive decode only uses DC coefficients, AC tables are not needed.
10
-
11
-
2. JPEGDecodeMCU_P: Guard pMCU writes against MCU_SKIP (-8).
12
-
The non-progressive JPEGDecodeMCU checks `iMCU >= 0` before writing to pMCU,
13
-
but JPEGDecodeMCU_P does not. When EIGHT_BIT_GRAYSCALE mode skips chroma
14
-
channels by passing MCU_SKIP, the unguarded write goes to a wild pointer
15
-
(sMCUs[0xFFFFF8]) and crashes.
16
-
17
-
Both patches are applied idempotently so it is safe to run on every build.
18
-
"""
19
-
20
-
Import("env")
21
-
import os
22
-
23
-
def patch_jpegdec(env):
24
-
# Find the JPEGDEC library in libdeps
25
-
libdeps_dir = os.path.join(env["PROJECT_DIR"], ".pio", "libdeps")
26
-
if not os.path.isdir(libdeps_dir):
27
-
return
28
-
for env_dir in os.listdir(libdeps_dir):
29
-
jpeg_inl = os.path.join(libdeps_dir, env_dir, "JPEGDEC", "src", "jpeg.inl")
30
-
if os.path.isfile(jpeg_inl):
31
-
_apply_ac_table_patch(jpeg_inl)
32
-
_apply_mcu_skip_patch(jpeg_inl)
33
-
34
-
def _apply_ac_table_patch(filepath):
35
-
MARKER = "// CrossPoint patch: skip AC tables for progressive JPEG"
36
-
with open(filepath, "r") as f:
37
-
content = f.read()
38
-
39
-
if MARKER in content:
40
-
return # already patched
41
-
42
-
OLD = """\
43
-
}
44
-
// now do AC components (up to 4 tables of 16-bit codes)"""
45
-
46
-
NEW = """\
47
-
}
48
-
""" + MARKER + """
49
-
// Progressive JPEG: only DC coefficients are decoded (first scan), so AC
50
-
// Huffman tables are not needed. Skip building them to avoid failing on
51
-
// 11+-bit AC codes that the optimized table builder cannot handle.
52
-
if (pJPEG->ucMode == 0xc2)
53
-
return 1;
54
-
// now do AC components (up to 4 tables of 16-bit codes)"""
55
-
56
-
if OLD not in content:
57
-
print("WARNING: JPEGDEC AC table patch target not found in %s — library may have been updated" % filepath)
58
-
return
59
-
60
-
content = content.replace(OLD, NEW, 1)
61
-
with open(filepath, "w") as f:
62
-
f.write(content)
63
-
print("Patched JPEGDEC: skip AC tables for progressive JPEG: %s" % filepath)
64
-
65
-
def _apply_mcu_skip_patch(filepath):
66
-
MARKER = "// CrossPoint patch: guard pMCU write for MCU_SKIP"
67
-
with open(filepath, "r") as f:
68
-
content = f.read()
69
-
70
-
if MARKER in content:
71
-
return # already patched
72
-
73
-
# Patch 1: Guard the unconditional pMCU[0] write in JPEGDecodeMCU_P.
74
-
# This is the DC coefficient store that crashes when iMCU = MCU_SKIP (-8).
75
-
OLD_DC = """\
76
-
pMCU[0] = (short)*iDCPredictor; // store in MCU[0]
77
-
}
78
-
// Now get the other 63 AC coefficients"""
79
-
80
-
NEW_DC = """\
81
-
""" + MARKER + """
82
-
if (iMCU >= 0)
83
-
pMCU[0] = (short)*iDCPredictor; // store in MCU[0]
84
-
}
85
-
// Now get the other 63 AC coefficients"""
86
-
87
-
if OLD_DC not in content:
88
-
print("WARNING: JPEGDEC MCU_SKIP patch target not found in %s — library may have been updated" % filepath)
89
-
return
90
-
91
-
content = content.replace(OLD_DC, NEW_DC, 1)
92
-
93
-
# Patch 2: Guard the successive approximation pMCU[0] write.
94
-
# This path is taken on subsequent scans (cApproxBitsHigh != 0), which we
95
-
# don't normally hit (we only decode first scan), but guard it for safety.
96
-
OLD_SA = """\
97
-
pMCU[0] |= iPositive;
98
-
}
99
-
goto mcu_done; // that's it"""
100
-
101
-
NEW_SA = """\
102
-
if (iMCU >= 0)
103
-
pMCU[0] |= iPositive;
104
-
}
105
-
goto mcu_done; // that's it"""
106
-
107
-
if OLD_SA in content:
108
-
content = content.replace(OLD_SA, NEW_SA, 1)
109
-
110
-
with open(filepath, "w") as f:
111
-
f.write(content)
112
-
print("Patched JPEGDEC: guard pMCU writes for MCU_SKIP in JPEGDecodeMCU_P: %s" % filepath)
113
-
114
-
# Apply patches immediately when this pre: script runs, before compilation starts.
115
-
# Previously used env.AddPreAction("buildprog", ...) which deferred patching until
116
-
# the link step — after the library was already compiled from unpatched source.
117
-
patch_jpegdec(env)