Turns out that, if we don't use functions that ensure reading until the
very end of the buffer, we only end up getting the very beginning of
samples and fill the rest with uninitialized data.
While at it, make sure that we read the data that is little endian as a
LittleEndian.
We are currently setting the physical mouse position to the visual
cursor content location. In a line containing only a multi-code point
emoji, this would set the cursor to column 1 rather than however many
code points there are.
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.
