All the prefixes of the testGIF produce errors today,
but they differ wildly in which errors: some are io.EOF,
others are io.ErrUnexpectedEOF, and others are gif-specific.
Make them all gif-specific to explain context, and make
any complaining about EOF be sure to mention the EOF
is unexpected.
Fixes#11390.
Change-Id: I742c39c88591649276268327ea314e68d1de1845
Reviewed-on: https://go-review.googlesource.com/17493
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Compression of paletted images is more efficient if they are not filtered.
This patch skips filtering for cbP8 images.
The improvements are demonstrated at https://github.com/olt/compressbenchFixes#16196
Change-Id: Ie973aad287cacf9057e394bb01cf0e4448a77618
Reviewed-on: https://go-review.googlesource.com/29872
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Benchmarks are much better for opaque fills and slightly worse on non
opaque fills. I think that on balance, this is still a win.
When the source is uniform(color.RGBA{0x11, 0x22, 0x33, 0xff}):
name old time/op new time/op delta
FillOver-8 966µs ± 1% 32µs ± 1% -96.67% (p=0.000 n=10+10)
FillSrc-8 32.4µs ± 1% 32.2µs ± 1% ~ (p=0.053 n=9+10)
When the source is uniform(color.RGBA{0x11, 0x22, 0x33, 0x44}):
name old time/op new time/op delta
FillOver-8 962µs ± 0% 1018µs ± 0% +5.85% (p=0.000 n=9+10)
FillSrc-8 32.2µs ± 1% 32.1µs ± 0% ~ (p=0.148 n=10+10)
Change-Id: I52ec6d5fcd0fbc6710cef0e973a21ee7827c0dd9
Reviewed-on: https://go-review.googlesource.com/28790
Reviewed-by: David Crawshaw <crawshaw@golang.org>
This is an error according to the spec, but Firefox and Google Chrome
seem OK with this.
Fixes#15059.
Change-Id: I841cf44e96655e91a2481555f38fbd7055a32202
Reviewed-on: https://go-review.googlesource.com/22546
Reviewed-by: Rob Pike <r@golang.org>
cmd and runtime were handled separately, and I'm intentionally skipped
syscall. This is the rest of the standard library.
CL generated mechanically with github.com/mdempsky/unconvert.
Change-Id: I9e0eff886974dedc37adb93f602064b83e469122
Reviewed-on: https://go-review.googlesource.com/22104
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Use one comparison to detect underflow and overflow simultaneously.
Use a shift, bitwise complement and uint8 type conversion to handle
clamping to upper and lower bound without additional branching.
Overall the new code is faster for a mix of
common case, underflow and overflow.
name old time/op new time/op delta
YCbCr-2 1.12ms ± 0% 0.64ms ± 0% -43.01% (p=0.000 n=48+47)
name old time/op new time/op delta
YCbCrToRGB/0-2 5.52ns ± 0% 5.77ns ± 0% +4.48% (p=0.000 n=50+49)
YCbCrToRGB/128-2 6.05ns ± 0% 5.52ns ± 0% -8.69% (p=0.000 n=39+50)
YCbCrToRGB/255-2 5.80ns ± 0% 5.77ns ± 0% -0.58% (p=0.000 n=50+49)
Found in collaboration with Josh Bleecher Snyder and Ralph Corderoy.
Change-Id: Ic5020320f704966f545fdc1ae6bc24ddb5d3d09a
Reviewed-on: https://go-review.googlesource.com/21910
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Fixes#14522.
As I said on that issue:
----
This is a progressive JPEG image. There are two dimensions of
progressivity: spectral selection (variables zs and ze in scan.go,
ranging in [0, 63]) and successive approximation (variables ah and al in
scan.go, ranging in [0, 8), from LSB to MSB, although ah=0 implicitly
means ah=8).
For this particular image, there are three components, and the SOS
markers contain this progression:
zs, ze, ah, al: 0 0 0 0 components: 0, 1, 2
zs, ze, ah, al: 1 63 0 0 components: 1
zs, ze, ah, al: 1 63 0 0 components: 2
zs, ze, ah, al: 1 63 0 2 components: 0
zs, ze, ah, al: 1 10 2 1 components: 0
zs, ze, ah, al: 11 63 2 1 components: 0
zs, ze, ah, al: 1 10 1 0 components: 0
The combination of all of these is complete (i.e. spectra 0 to 63 and
bits 8 exclusive to 0) for components 1 and 2, but it is incomplete for
component 0 (the luma component). In particular, there is no data for
component 0, spectra 11 to 63 and bits 1 exclusive to 0.
The image/jpeg code, as of Go 1.6, waits until both dimensions are
complete before performing the de-quantization, IDCT and copy to an
*image.YCbCr. This is the "if zigEnd != blockSize-1 || al != 0 { ...
continue }" code and associated commentary in scan.go.
Almost all progressive JPEG images end up complete in both dimensions
for all components, but this particular image is incomplete for
component 0, so the Go code never writes anything to the Y values of the
resultant *image.YCbCr, which is why the broken output is so dark (but
still looks recognizable in terms of red and blue hues).
My reading of the ITU T.81 JPEG specification (Annex G) doesn't
explicitly say that this is a valid image, but it also doesn't rule it
out.
In any case, the fix is, for progressive JPEG images, to always
reconstruct the decoded blocks (by performing the de-quantization, IDCT
and copy to an *image.YCbCr), regardless of whether or not they end up
complete. Note that, in Go, the jpeg.Decode function does not return
until the entire image is decoded, so we still only want to reconstruct
each block once, not once per SOS (Start Of Scan) marker.
----
A test image was also added, based on video-001.progressive.jpeg. When
decoding that image, inserting a
println("nComp, zs, ze, ah, al:", nComp, zigStart, zigEnd, ah, al)
into decoder.processSOS in scan.go prints:
nComp, zs, ze, ah, al: 3 0 0 0 1
nComp, zs, ze, ah, al: 1 1 5 0 2
nComp, zs, ze, ah, al: 1 1 63 0 1
nComp, zs, ze, ah, al: 1 1 63 0 1
nComp, zs, ze, ah, al: 1 6 63 0 2
nComp, zs, ze, ah, al: 1 1 63 2 1
nComp, zs, ze, ah, al: 3 0 0 1 0
nComp, zs, ze, ah, al: 1 1 63 1 0
nComp, zs, ze, ah, al: 1 1 63 1 0
nComp, zs, ze, ah, al: 1 1 63 1 0
In other words, video-001.progressive.jpeg contains 10 different scans.
This little program below drops half of them (remembering to keep the
"\xff\xd9" End of Image marker):
----
package main
import (
"bytes"
"io/ioutil"
"log"
)
func main() {
sos := []byte{0xff, 0xda}
eoi := []byte{0xff, 0xd9}
src, err := ioutil.ReadFile("video-001.progressive.jpeg")
if err != nil {
log.Fatal(err)
}
b := bytes.Split(src, sos)
println(len(b)) // Prints 11.
dst := bytes.Join(b[:5], sos)
dst = append(dst, eoi...)
if err := ioutil.WriteFile("video-001.progressive.truncated.jpeg", dst, 0666); err != nil {
log.Fatal(err)
}
}
----
The video-001.progressive.truncated.jpeg was converted to png via
libjpeg and ImageMagick:
djpeg -nosmooth video-001.progressive.truncated.jpeg > tmp.tga
convert tmp.tga video-001.progressive.truncated.png
rm tmp.tga
Change-Id: I72b20cd4fb6746d36d8d4d587f891fb3bc641f84
Reviewed-on: https://go-review.googlesource.com/21062
Reviewed-by: Rob Pike <r@golang.org>
Ignore superfluous trailing IDAT chunks which were not consumed when decoding
the image. This change fixes decoding of valid images in which a zero-length
IDAT chunk appears after the actual image data. It also prevents decoding of
trailing garbage IDAT chunks or maliciously embedded additional images.
Fixes#14936
Change-Id: I8c76cfa9a03496d9576f72bed2db109271f97c5e
Reviewed-on: https://go-review.googlesource.com/21045
Reviewed-by: Nigel Tao <nigeltao@golang.org>
The tree's pretty inconsistent about single space vs double space
after a period in documentation. Make it consistently a single space,
per earlier decisions. This means contributors won't be confused by
misleading precedence.
This CL doesn't use go/doc to parse. It only addresses // comments.
It was generated with:
$ perl -i -npe 's,^(\s*// .+[a-z]\.) +([A-Z]),$1 $2,' $(git grep -l -E '^\s*//(.+\.) +([A-Z])')
$ go test go/doc -update
Change-Id: Iccdb99c37c797ef1f804a94b22ba5ee4b500c4f7
Reviewed-on: https://go-review.googlesource.com/20022
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Dave Day <djd@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This is a subset of https://golang.org/cl/20022 with only the copyright
header lines, so the next CL will be smaller and more reviewable.
Go policy has been single space after periods in comments for some time.
The copyright header template at:
https://golang.org/doc/contribute.html#copyright
also uses a single space.
Make them all consistent.
Change-Id: Icc26c6b8495c3820da6b171ca96a74701b4a01b0
Reviewed-on: https://go-review.googlesource.com/20111
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This makes NYCbCrA consistent with YCbCr.
Fixes#13706.
Change-Id: Ifced84372e4865925fa6efef9ca2f1de43da70e0
Reviewed-on: https://go-review.googlesource.com/18115
Reviewed-by: Rob Pike <r@golang.org>
This change addresses an integer underflow appearing only on systems
using a 32-bit int type. The patch addresses the problem by limiting the
length of unknown chunks to 0x7fffffff. This value appears to already be
checked for when parsing other chunk types, so the bug shouldn't appear
elsewhere in the package. The PNG spec recommends the maximum size for
any chunk to remain under 2^31, so this shouldn't cause errors with
valid images.
Fixes#12687
Change-Id: I17f0e1683515532c661cf2b0b2bc65309d1b7bb7
Reviewed-on: https://go-review.googlesource.com/14766
Reviewed-by: Nigel Tao <nigeltao@golang.org>
http://www.w3.org/TR/PNG/#11IHDR says that "Zero is an invalid value".
This change only affects the decoder. The encoder already checks
non-positive instead of negative.
Fixes#12545.
Change-Id: Iba40e1a2f4e0eec8b2fbcd3bbdae886311434da7
Reviewed-on: https://go-review.googlesource.com/14411
Reviewed-by: Rob Pike <r@golang.org>
We could undoubtedly squeeze even more out of these loops, and in the
long term, a better compiler would be smarter with bounds checks, but in
the short term, this small change is an easy win.
benchmark old ns/op new ns/op delta
BenchmarkFillOver-8 1619470 1323192 -18.29%
BenchmarkCopyOver-8 1129369 1062787 -5.90%
BenchmarkGlyphOver-8 420070 378608 -9.87%
On github.com/golang/freetype/truetype's BenchmarkDrawString:
benchmark old ns/op new ns/op delta
BenchmarkDrawString-8 9561435 8807019 -7.89%
Change-Id: Ib1c6271ac18bced85e0fb5ebf250dd57d7747e75
Reviewed-on: https://go-review.googlesource.com/14093
Reviewed-by: Rob Pike <r@golang.org>
Before, calling the RGBA method of YCbCr color would return red values
in the range [0x0080, 0xff80]. After, the range is [0x0000, 0xffff] and
is consistent with what Gray colors' RGBA method returns. In particular,
pure black, pure white and every Gray color in between are now exactly
representable as a YCbCr color.
This fixes a regression from Go 1.4 (where YCbCr{0x00, 0x80, 0x80} was
no longer equivalent to pure black), introduced by golang.org/cl/8073 in
the Go 1.5 development cycle. In Go 1.4, the +0x80 rounding was not
noticable when Cb == 0x80 && Cr == 0x80, because the YCbCr to RGBA
conversion truncated to 8 bits before multiplying by 0x101, so the
output range was [0x0000, 0xffff].
The TestYCbCrRoundtrip fuzzy-match tolerance grows from 1 to 2 because
the YCbCr to RGB conversion now maps to an ever-so-slightly larger
range, along with the usual imprecision of accumulating rounding errors.
Also s/int/int32/ in ycbcr.go. The conversion shouldn't overflow either
way, as int is always at least 32 bits, but it does make it clearer that
the computation doesn't depend on sizeof(int).
Fixes#11691
Change-Id: I538ca0adf7e040fa96c5bc8b3aef4454535126b9
Reviewed-on: https://go-review.googlesource.com/12220
Reviewed-by: Rob Pike <r@golang.org>
This rolls back most of golang.org/cl/8841, aka 2f98bac310, and makes a
different fix. It keeps the TestTruncatedSOSDataDoesntPanic test
introduced by that other CL, which obviously still passes after this CL.
Fixes#11650, a regression (introduced by cl/8841) from Go 1.4.
The original cl/8841 changed the image/jpeg not to panic on an input
given in #10387. We still do not panic on that input, after this CL.
I have a corpus of over 160,000 JPEG images, a sample of a web crawl.
The image/jpeg code ran happily over that whole corpus both before and
after this CL, although that corpus clearly didn't catch the regression
in the first place.
This code was otherwise tested manually. I don't think that it's trivial
to synthesize a JPEG input that happens to run out of Huffman data at
just the right place. The test image attached to #11650 obviously has
that property, but I don't think we can simply add that test image to
the repository: it's 227KiB, and I don't know its copyright status.
I also looked back over the issue tracker for problematic JPEGs that
people have filed. The Go code, after this CL, is still happy on these
files in my directory:
issue2362a.jpeg
issue3916.jpeg
issue3976.jpeg
issue4084.jpeg
issue4259.jpeg
issue4291.jpeg
issue4337.jpeg
issue4500.jpeg
issue4705.jpeg
issue4975.jpeg
issue5112.jpeg
issue6767.jpeg
issue9888.jpeg
issue10133.jpeg
issue10357.jpeg
issue10447.jpeg
issue11648.jpeg
issue11650.jpeg
There were other images attached in the issue tracker that aren't
actually valid JPEGs. They failed both before and after this CL:
broken-issue2362b.jpeg
broken-issue6450.jpeg
broken-issue8693.jpeg
broken-issue10154.jpeg
broken-issue10387.jpeg
broken-issue10388.jpeg
broken-issue10389.jpeg
broken-issue10413.jpeg
In summary, this CL fixes#11650 and, after some automated and manual
testing, I don't think introduces new regressions.
Change-Id: I30b67036e9b087f3051d57dac7ea05fb4fa36f66
Reviewed-on: https://go-review.googlesource.com/12163
Reviewed-by: Rob Pike <r@golang.org>
The one in misc/makerelease/makerelease.go is particularly bad and
probably warrants rotating our keys.
I didn't update old weekly notes, and reverted some changes involving
test code for now, since we're late in the Go 1.5 freeze. Otherwise,
the rest are all auto-generated changes, and all manually reviewed.
Change-Id: Ia2753576ab5d64826a167d259f48a2f50508792d
Reviewed-on: https://go-review.googlesource.com/12048
Reviewed-by: Rob Pike <r@golang.org>
The second (fallback) draw is a no-op, but it's a non-trivial amount of work.
Fixes#11550.
benchmark old ns/op new ns/op delta
BenchmarkPaletted-4 16301219 7309568 -55.16%
Change-Id: Ic88c537b2b0c710cf517888f3dd15cb702dd142f
Reviewed-on: https://go-review.googlesource.com/11858
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
It was otherwise not being preserved across
specific Decode->Encode->Decode calls.
Fixes#11287
Change-Id: I40602da7fa39ec67403bed52ff403f361c6171bb
Reviewed-on: https://go-review.googlesource.com/11256
Reviewed-by: Nigel Tao <nigeltao@golang.org>
These tests were broken by https://go-review.googlesource.com/#/c/11227/
which fixed the LZW encoder to reject invalid input.
For TestNoPalette, the LZW encoder with a litWidth of 2 now rejects an
input byte of 128, so we change 128 to 3, as 3 <= (1<<2 - 1).
For TestPixelOutsidePaletteRange, the LZW encoder similarly rejects an
input byte of 255. Prior to golang.org/cl/11227, the encoder (again with
a litWidth of 2) accepted the 255 input byte, but masked it with (1<<2 -
1), so that the 255 test case was effectively the same as the 3 test
case. After that LZW CL, the 255 input byte is simply invalid, so we
remove it as a test case. The test still tests pixels outside of the
palette range, since 3 >= the length of the global palette, which is 2.
Change-Id: I50be9623ace016740e34801549c15f83671103eb
Reviewed-on: https://go-review.googlesource.com/11273
Reviewed-by: David Symonds <dsymonds@golang.org>
A frame that tries to use the global palette when it has
not been given should result in an error, not an image
with no palette at all.
Fixes#11150.
Change-Id: If0c3a201a0ac977eee2b7a5dc68930c0c5787f40
Reviewed-on: https://go-review.googlesource.com/11064
Reviewed-by: Nigel Tao <nigeltao@golang.org>
isn't (0, 0).
Also fix a s/b.Min.X/b.Max.X/ typo in bounds checking.
Fixes#10676
Change-Id: Ie5ff7ec20ca30367a8e65d32061959a2d8e089e9
Reviewed-on: https://go-review.googlesource.com/9712
Reviewed-by: Rob Pike <r@golang.org>
global color table.
Change-Id: Ia38f75708ed5e5b430680a1eecafb4fc8047269c
Reviewed-on: https://go-review.googlesource.com/9467
Reviewed-by: Rob Pike <r@golang.org>
GIF's bounds.
Also change the implicit Config Width and Height to be the
Rectangle.Max, not the Dx and Dy, of the first frame's bounds. For the
case where the first frame's bounds is something like (5,5)-(8,8), the
overall width should be 8, not 3.
Change-Id: I3affc484f5e32941a36f15517a92ca8d189d9c22
Reviewed-on: https://go-review.googlesource.com/9465
Reviewed-by: Rob Pike <r@golang.org>
The previous CL implemented decoding, but not encoding.
Also return the global color map (if present) for DecodeConfig.
Change-Id: I3b99c93720246010c9fe0924dc40a67875dfc852
Reviewed-on: https://go-review.googlesource.com/9389
Reviewed-by: Rob Pike <r@golang.org>
call unreadByteStuffedByte.
If ensureNBits was due to an io.EOF that was translated to
jpeg.errShortHuffmanData, then we may have read no bytes, so there is no
byte-stuffed-byte to unread.
Fixes#10387
Change-Id: I39a3842590c6cef2aa48943288d52f603338b44d
Reviewed-on: https://go-review.googlesource.com/8841
Reviewed-by: Rob Pike <r@golang.org>
