This type of image isn't common, and you can probably only find one by
generating it yourself. It can be done using `cjpeg` with the -scan
argument.
This image has been generated with the following scan file:
0: 0 63 0 0;
1: 0 63 0 0;
2: 0 63 0 0;
Scan with only one component are by definition not interleaved, meaning
that each value is linearly ordered in the stream. Grayscale images
were supported thanks to a hack, by forcing the subsampling to 1.
Now we properly support grayscale image with other subsampling (even if
it doesn't make sense) and more generally scans with only one component
and any sampling factors.
While this solution is more general than the last one it also feels a
bit hackish. We should probably refactor the way we iterate over
components and macroblocks. But that's work for latter, especially when
we will add support for other subsampling than 4-2-2.
Huffman streams are encountered in the scan segment. They have nothing
to do outside this segment, hence they shouldn't outlive the scan.
Please note that this patch changes behavior. The stream is now reset
after each scan.
A scan can contain fewer components that the full image. However, if
there is multiple components, they have to follow the ordering of the
frame header. It means that we can loop over components of the image
and skip those that doesn't correspond.
For now, we exit after the first scan without needing to parse `EOI`.
However, to read scans in a loop we will need to properly detect and
parse `EOI`.
This patch brings us closer to the spec point of view. And while it
makes no functional changes, it reduces the number of places where you
can misuse scan-specific data and improve support for multiple scans.
10ms (the default) is ridiculous and causes all kinds of glitches if we
actually want to have a low-latency queue.
<https://gitlab.com/qemu-project/qemu/-/issues/1076#note_996636777>
suggests 2ms (and no lower than 1ms). This improves audio glitch
resistance at our current 512 sample buffer size, but going lower is
still not possible.
Nobody made use of the ErrorOr return value and it just added more
chance of confusion, since it was not clear if failing to sniff an
image should return an error or false. The answer was false, if you
returned Error you'd crash the ImageDecoder.
This object is responsible for handling async functions in bytecode,
and this commit fully rewrites it, now it does:
* creates and keeps alive a top level promise, which callers can attach
their `then` clauses
* creates and clear a handle to itself, to assure that it does not get
garbage collected
* properly handles all possible ways a async function could halt and
when possible continues the execution immediately
We use generators in bytecode to approximate async functions, but the
code generated by AwaitExpressions did not have the value processing
paths that Yield requires, eg the `generator.throw()` path, which is
used by AsyncFunctionDriverWrapper to signal Promise rejections.
This uses a newly added instruction `ScheduleJump`
This instruction tells the finally proceeding it, that instead of
jumping to it's next block it should jump to the designated block.
To achieve this it now uses recursive descend, to make the state
managements easier.
With this we now correctly handle try-catch-finally blocks correctly,
modeling all possible controll flows between these blocks, which allows
analysis and optimization passes to make more accurate descisions about
accessibility of the enclosed blocks
The output of the DeprecatedString::bijective_base_from() is now
correct for numbers larger than base^2.
This makes column names display correctly in Spreadsheet.
Turns out extended-lossless-animated.webp did have a loop count of 0.
So I opened it in Hex Fiend and changed the byte at position 42
(which is the first byte of the little-endian u16 storing the loop
count) to 0x2A, so that the test can compare the loop count to something
not 0.
This commit adds a "Apply Mask" action which merges the active layer
mask with the layer bitmap. The option is only displayed if the active
layer is masked.
Imported functions in Wasm may throw JS exceptions, and we need to
preserve these exceptions so we can pass them to the calling JS code.
This also adds a `assert_wasm_result()` API to Result for cases where
only Wasm traps or values are expected (e.g. internal uses) to avoid
making LibWasm (pointlessly) handle JS exceptions that will never show
up in reality.
