nsBMPEncoder produces either BMPv3 or BMPv5 files. (See the Version enum which
only has VERSION_3 and VERSION_5 values, and ParseOptions()'s handling of the
|version| parameter.
Nonetheless, there is some code to handle encoding of BMPv2 files. This patch
removes this.
The FileHeader and V5InfoHeader structs are shared by the BMP decoder and
encoder. But most of the fields within those structs are actually unused by the
decoder. It makes things clearer if we create a decoder-only struct that
contains the used fields, and then make FileHeader and V5InfoHeader only used
by the encoder. This patch does that.
This patch also renames BMPFileHeaders.h as BMPHeaders.h, which is now a better
name for it.
The wrinkle here is that while we can pass a UniquePtr to
ConvertHostARGBRow, we can't pass UniquePtr to
EncodeImageDataRow{24,32}, as the latter get called with raw pointers
out of our control.
This patch is a major overhaul of nsBMPDecoder.
The patch improves the code in the following ways.
- It converts nsBMPDecoder to use StreamingLexer, which makes it much easier to
read.
- It adds a detailed comment about the BMP format at the top of
nsBMPDecoder.cpp.
- It fixes lots of inconsistent indenting.
- It moves |bihsize| from |mBFH| to |mBIH| to match the file format and common
sense. The avoids the need for the confusing LENGTH/INTERNAL_LENGTH
distinction.
- It renames most of the types in BMPFileHeader.h, so they have better names,
in StudlyCaps form, and within the new |bmp| namespace.
- It removes the BMP_HEADER_LENGTH struct and inlines its values directly into
the two places they were used.
- It removes the MOZ_LOG logging done on some of the failure cases. (Most
failure cases lacked logging so why bother with some?)
- It removes over 200 lines of code, despite the addition of the big format
comment.
The patch changes the way BMPs are decoded as follows.
- It adds stricter testing of the InfoHeader length, rejecting files with bad
values.
- It moves all header sanity checking that can lead to file rejection into the
metadata decode phase. (Previously, bpp/compression consistency checking did
not occur during a metadata decode.)
- It removes BMPINFOHEADER::ALPHABITFIELDS, which was (a) a weird WinCE-only
thing, and (b) we didn't actually allow it, and (c) we used the value 4
instead of 6(!).
- It rejects the previously-accepted compression==RLE4 && bpp=1 combination
because it doesn't make sense.
- It removes a fudge in RLE absolute mode handling that permitted one pixel too
many in a row but only if the row's width was odd(!)
- It now rejects a file with a negative gap between the color table and the
pixel data.
The patch leaves the following problems unaddressed.
- If bpp==32 we totally ignore compression==BITFIELDS and treat it like
compression=RGB.
- Transparency as specified in WinBMPv{4,5} isn't handled at all.
These will be fixed in follow-ups.
All these changes affect (for the better) the results of the following tests
that will be added in part 2:
- g/pal8v4.bmp
- g/pal8v5.bmp
- q/pal8os2sp.bmp
- q/pal8os2v2.bmp
- q/pal8os2v2-16.bmp
- b/badheadersize.bmp
- b/badpalettesize.bmp
- b/badrle.bmp
The patch removes 455 occurrences of FAIL_ON_WARNINGS from moz.build files, and
adds 78 instances of ALLOW_COMPILER_WARNINGS. About half of those 78 are in
code we control and which should be removable with a little effort.
This is straightforward mapping of PR_LOG levels to their LogLevel
counterparts:
PR_LOG_ERROR -> LogLevel::Error
PR_LOG_WARNING -> LogLevel::Warning
PR_LOG_WARN -> LogLevel::Warning
PR_LOG_INFO -> LogLevel::Info
PR_LOG_DEBUG -> LogLevel::Debug
PR_LOG_NOTICE -> LogLevel::Debug
PR_LOG_VERBOSE -> LogLevel::Verbose
Instances of PRLogModuleLevel were mapped to a fully qualified
mozilla::LogLevel, instances of PR_LOG levels in #defines were mapped to a
fully qualified mozilla::LogLevel::* level, and all other instances were
mapped to us a shorter format of LogLevel::*.
Bustage for usage of the non-fully qualified LogLevel were fixed by adding
|using mozilla::LogLevel;| where appropriate.
This is straightforward mapping of PR_LOG levels to their LogLevel
counterparts:
PR_LOG_ERROR -> LogLevel::Error
PR_LOG_WARNING -> LogLevel::Warning
PR_LOG_WARN -> LogLevel::Warning
PR_LOG_INFO -> LogLevel::Info
PR_LOG_DEBUG -> LogLevel::Debug
PR_LOG_NOTICE -> LogLevel::Debug
PR_LOG_VERBOSE -> LogLevel::Verbose
Instances of PRLogModuleLevel were mapped to a fully qualified
mozilla::LogLevel, instances of PR_LOG levels in #defines were mapped to a
fully qualified mozilla::LogLevel::* level, and all other instances were
mapped to us a shorter format of LogLevel::*.
Bustage for usage of the non-fully qualified LogLevel were fixed by adding
|using mozilla::LogLevel;| where appropriate.
This is straightforward mapping of PR_LOG levels to their LogLevel
counterparts:
PR_LOG_ERROR -> LogLevel::Error
PR_LOG_WARNING -> LogLevel::Warning
PR_LOG_WARN -> LogLevel::Warning
PR_LOG_INFO -> LogLevel::Info
PR_LOG_DEBUG -> LogLevel::Debug
PR_LOG_NOTICE -> LogLevel::Debug
PR_LOG_VERBOSE -> LogLevel::Verbose
Instances of PRLogModuleLevel were mapped to a fully qualified
mozilla::LogLevel, instances of PR_LOG levels in #defines were mapped to a
fully qualified mozilla::LogLevel::* level, and all other instances were
mapped to us a shorter format of LogLevel::*.
Bustage for usage of the non-fully qualified LogLevel were fixed by adding
|using mozilla::LogLevel;| where appropriate.
The distinction between moz_malloc/moz_free and malloc/free is not
interesting. We are inconsistent in our use of one or the other, and
I wouldn't be surprised if we are mixing them anyways.
