Add an interface to decode frames beyond the first in SkCodec, and
add an implementation for SkGifCodec.
Add getFrameData to SkCodec. This method reads ahead in the stream
to return a vector containing meta data about each frame in the image.
This is not required in order to decode frames beyond the first, but
it allows a client to learn extra information:
- how long the frame should be displayed
- whether a frame should be blended with a prior frame, allowing the
client to provide the prior frame to speed up decoding
Add a new fields to SkCodec::Options:
- fFrameIndex
- fHasPriorFrame
The API is designed so that SkCodec never caches frames. If a
client wants a frame beyond the first, they specify the frame in
Options.fFrameIndex. If the client does not have the
frame's required frame (the frame that this frame must be blended on
top of) cached, they pass false for
Options.fHasPriorFrame. Unless the frame is
independent, the codec will then recursively decode all frames
necessary to decode fFrameIndex. If the client has the required frame
cached, they can put it in the dst they pass to the codec, and the
codec will only draw fFrameIndex onto it.
Replace SkGifCodec's scanline decoding support with progressive
decoding, and update the tests accordingly.
Implement new APIs in SkGifCodec. Instead of using gif_lib, use
GIFImageReader, imported from Chromium (along with its copyright
headers) with the following changes:
- SkGifCodec is now the client
- Replace blink types
- Combine GIFColorMap::buildTable and ::getTable into a method that
creates and returns an SkColorTable
- Input comes from an SkStream, instead of a SegmentReader. Add
SkStreamBuffer, which buffers the (potentially partial) stream in
order to decode progressively.
(FIXME: This requires copying data that previously was read directly
from the SegmentReader. Does this hurt performance? If so, can we
fix it?)
- Remove UMA code
- Instead of reporting screen width and height to the client, allow the
client to query for it
- Fail earlier if the first frame AND screen have size of zero
- Compute required previous frame when adding a new one
- Move GIFParseQuery from GIFImageDecoder to GIFImageReader
- Allow parsing up to a specific frame (to skip parsing the rest of the
stream if a client only wants the first frame)
- Compute whether the first frame has alpha and supports index 8, to
create the SkImageInfo. This happens before reporting that the size
has been decoded.
Add GIFImageDecoder::haveDecodedRow to SkGifCodec, imported from
Chromium (along with its copyright header), with the following changes:
- Add support for sampling
- Use the swizzler
- Keep track of the rows decoded
- Do *not* keep track of whether we've seen alpha
Remove SkCodec::kOutOfOrder_SkScanlineOrder, which was only used by GIF
scanline decoding.
Call onRewind even if there is no stream (SkGifCodec needs to clear its
decoded state so it will decode from the beginning).
Add a method to SkSwizzler to access the offset into the dst, taking
subsetting into account.
Add a GM that animates a GIF.
Add tests for the new APIs.
*** Behavior changes:
* Previously, we reported that an image with a subset frame and no transparent
index was opaque and used the background index (if present) to fill the
background. This is necessary in order to support index 8, but it does not
match viewers/browsers I have seen. Examples:
- Chromium and Gimp render the background transparent
- Firefox, Safari, Linux Image Viewer, Safari Preview clip to the frame (for
a single frame image)
This CL matches Chromium's behavior and renders the background transparent.
This allows us to have consistent behavior across products and simplifies
the code (relative to what we would have to do to continue the old behavior
on Android). It also means that we will no longer support index 8 for some
GIFs.
* Stop checking for GIFSTAMP - all GIFs should be either 89a or 87a.
This matches Chromium. I suspect that bugs would have been reported if valid
GIFs started with "GIFVER" instead of "GIF89a" or "GIF87a" (but did not decode
in Chromium).
*** Future work not included in this CL:
* Move some checks out of haveDecodedRow, since they are the same for the
entire frame e.g.
- intersecting the frameRect with the full image size
- whether there is a color table
* Change when we write transparent pixels
- In some cases, Chromium deemed this unnecessary, but I suspect it is slower
than the fallback case. There will continue to be cases where we should
*not* write them, but for e.g. the first pass where we have already
cleared to transparent (which we may also be able to skip) writing the
transparent pixels will not make anything incorrect.
* Report color type and alpha type per frame
- Depending on alpha values, disposal methods, frame rects, etc, subsequent
frames may have different properties than the first.
* Skip copies of the encoded data
- We copy the encoded data in case the stream is one that cannot be rewound,
so we can parse and then decode (possibly not immediately). For some input
streams, this is unnecessary.
- I was concerned this cause a performance regression, but on average the
new code is faster than the old for the images I tested [1].
- It may cause a performance regression for Chromium, though, where we can
always move back in the stream, so this should be addressed.
Design doc:
https://docs.google.com/a/google.com/document/d/12Qhf9T92MWfdWujQwCIjhCO3sw6pTJB5pJBwDM1T7Kc/
[1] https://docs.google.com/a/google.com/spreadsheets/d/19V-t9BfbFw5eiwBTKA1qOBkZbchjlTC5EIz6HFy-6RI/
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=2045293002
Review-Url: https://codereview.chromium.org/2045293002
Reason for revert:
Breaks Ubuntu and Mac CMAKE
Original issue's description:
> Make SkPicture/SkImageGenerator default to SkCodec
>
> Remove reference to SkImageDecoder from SkPicture. Make the default
> InstallPixelRefProc passed to CreateFromStream use
> SkImageGenerator::NewFromEncoded instead.
>
> Make SkImageGenerator::NewFromEncoded create an SkCodecImageGenerator.
> Remove the old version that used SkImageDecoder.
>
> Remove all versions of lazy_decode_bitmap/LazyDecodeBitmap. The default
> now behaves lazily.
>
> Update all clients to use the default.
>
> Move SkImageDecoderGenerator into KtxTest.cpp, and use it directly.
>
> BUG=skia:4691
> BUG=skia:4290
> GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1671193002
>
> Committed: https://skia.googlesource.com/skia/+/026388a01864c74208ad57d1ba4f711602d101c6TBR=msarett@google.com,reed@google.com,scroggo@google.com
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:4691
Review URL: https://codereview.chromium.org/1685963004
Remove reference to SkImageDecoder from SkPicture. Make the default
InstallPixelRefProc passed to CreateFromStream use
SkImageGenerator::NewFromEncoded instead.
Make SkImageGenerator::NewFromEncoded create an SkCodecImageGenerator.
Remove the old version that used SkImageDecoder.
Remove all versions of lazy_decode_bitmap/LazyDecodeBitmap. The default
now behaves lazily.
Update all clients to use the default.
Move SkImageDecoderGenerator into KtxTest.cpp, and use it directly.
BUG=skia:4691
BUG=skia:4290
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1671193002
Review URL: https://codereview.chromium.org/1671193002
Bump SK_IMAGE_VERSION to test the images in v2 in GoogleStorage, which
includes the images from v1 plus test images for SkRawCodec.
Only define skia_decodes_raw on platforms that support it, rather than
defining it always and checking additional conditions to determine
whether to support raw. Further, define it and SK_CODEC_DECODES_RAW
for all targets, so we can use the compile flag in other targets.
In DM, exclude the raw extensions if SK_CODEC_DECODES_RAW is not defined.
Blacklist raw extensions on NexusPlayer, which was running out of memory
when running them.
BUG=skia:4829
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1612113002
Review URL: https://codereview.chromium.org/1612113002
Reason for revert:
Speculative to fix windows bots
Original issue's description:
> Treat bad values passed to --images as a fatal error
>
> If an option is passed to --images that is either a non-existent path or
> a folder with no images matching the supported types, assume this is
> an error and exit, so they can supply a valid path instead.
>
> Share code between DM and nanobench in SkCommonFlags.
>
> nanobench now behaves more like DM - it will check a directory for
> images that match the supported extensions.
>
> Only consider image paths ending in RAW suffixes as images if
> SK_CODE_DECODES_RAW is defined. This prevents us from seeing failure
> to decode errors on platforms that cannot decode it.
>
> GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1611323004
>
> Committed: https://skia.googlesource.com/skia/+/7579786f3bd5a8fda84a1abc45b16213c3371f93TBR=mtklein@google.com,borenet@google.com,msarett@google.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
# Not skipping CQ checks because original CL landed more than 1 days ago.
Review URL: https://codereview.chromium.org/1653543002
If an option is passed to --images that is either a non-existent path or
a folder with no images matching the supported types, assume this is
an error and exit, so they can supply a valid path instead.
Share code between DM and nanobench in SkCommonFlags.
nanobench now behaves more like DM - it will check a directory for
images that match the supported extensions.
Only consider image paths ending in RAW suffixes as images if
SK_CODE_DECODES_RAW is defined. This prevents us from seeing failure
to decode errors on platforms that cannot decode it.
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1611323004
Review URL: https://codereview.chromium.org/1611323004
Local timing says this 4-byte Paeth function takes about 0.3x the time the serial libpng code does, dropping from ~10 cycles per byte to ~2.9.
bpp=4 is mainly an easy demo. This approach can work for any bpp up to 16, 1 pixel at a time, at roughly the same cost per pixel. Doing more than 1 pixel at a time is a tricky math problem I have yet to attempt to solve.
Everything here can be trivially downgraded to MMX, supporting bpp up to 8. It seems to be a little slower (~3.5 cycles per byte), but it would make the code compatible with every x86 that can still power on.
I've tried four approaches:
- this way;
- doing things naively in 16-bit;
- a 16-bit version that requires division by 3 (i.e. mulhi_epu16(..., 0x5580) );
- a mostly 8-bit version of the same.
They're all fine, but this one is consistently the fastest I've measured.
I'd be happy to settle on the naive 16-bit version too, which would have a very clear implementation that's only minorly slower than this version. The other two are way more complicated, and would require us to draw some serious ASCII diagrams to explain.
I have learned that the .skp serialization tests (serialize-8888) have a nice side effect of testing the correctness of these filters!
(Since writing the description above, I've bumped things up to {Paeth,Sub,Avg} x { 3 bpp, 4 bpp }.)
BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1573943002
Review URL: https://codereview.chromium.org/1573943002
Disable SkImageDecoder's code which relies on Android's customized
libpng and libjpeg. Build standard versions of libpng and libjpeg-turbo
everywhere. The SkImageDecoder code has been replaced with SkCodec, which
can decode subsets using standard library APIs
BUG=skia:
Review URL: https://codereview.chromium.org/1406153015
We will implement this API using SkCodecs.
SkAndroidCodecs will be used to implement the
BitmapRegionDecoder Java API (and possibly
BitmapFactory).
BUG=skia:
Review URL: https://codereview.chromium.org/1406223002
Rather than implementing some sort of "fill" in every
SkCodec subclass for incomplete images, let's make the
parent class handle this situation.
This includes an API change to SkCodec.h
SkCodec::getScanlines() now returns the number of lines it
read successfully, rather than an SkCodec::Result enum.
getScanlines() most often fails on an incomplete input, in
which case it is useful to know how many lines were
successfully decoded - this provides more information than
kIncomplete vs kSuccess. We do lose information when the
API is used improperly, as we are no longer able to return
kInvalidParameter or kScanlineNotStarted.
Known Issues:
Does not work for incomplete fFrameIsSubset gifs.
Does not work for incomplete icos.
BUG=skia:
Review URL: https://codereview.chromium.org/1332053002
Benefits:
- This mimics other decoding APIs (including the ones SkCodec relies
on, e.g. a png_struct, which can be used to decode an entire image or
one line at a time).
- It allows a client to ask us to do what we can do efficiently - i.e.
start from encoded data and either decode the whole thing or scanlines.
- It removes the duplicate methods which appeared in both SkCodec and
SkScanlineDecoder (some of which, e.g. in SkJpegScanlineDecoder, just
call fCodec->sameMethod()).
- It simplifies moving more checks into the base class (e.g. the
examples in skbug.com/4284).
BUG=skia:4175
BUG=skia:4284
=====================================================================
SkScanlineDecoder.h/.cpp:
Removed.
SkCodec.h/.cpp:
Add methods, enums, and variables which were previously in
SkScanlineDecoder.
Default fCurrScanline to -1, as a sentinel that start has not been
called.
General changes:
Convert SkScanlineDecoders to SkCodecs.
General changes in SkCodec subclasses:
Merge SkScanlineDecoder implementation into SkCodec. Most (all?) owned
an SkCodec, so they now call this-> instead of fCodec->.
SkBmpCodec.h/.cpp:
Replace the unused rowOrder method with an override for
onGetScanlineOrder.
Make getDstRow const, since it is called by onGetY, which is const.
SkCodec_libpng.h/.cpp:
Make SkPngCodec an abstract class, with two subclasses which handle
scanline decoding separately (they share code for decoding the entire
image). Reimplement onReallyHasAlpha so that it can return the most
recent result (e.g. after a scanline decode which only decoded part
of the image) or a better answer (e.g. if the whole image is known to
be opaque).
Compute fNumberPasses early, so we know which subclass to instantiate.
Make SkPngInterlaceScanlineDecoder use the base class' fCurrScanline
rather than a separate variable.
CodexTest.cpp:
Add tests for the state changes in SkCodec (need to call start before
decoding scanlines; calling getPixels means that start will need to
be called again before decoding more scanlines).
Add a test which decodes in stripes, currently only used for an
interlaced PNG.
TODO: Add tests for onReallyHasAlpha.
Review URL: https://codereview.chromium.org/1365313002
Will regress behavior on gold on test32bfv4.bmp, where we
will no longer fix transparent decodes.
TODO: Start fixing transparent decodes again, or decide
that we don't want to fix them and remove isTransparent
from SkSwizzler. I think this may become more clear when I
start implementing the scanline decoder.
BUG=skia:
Review URL: https://codereview.chromium.org/1258863008
Prior to this CL, if a client wanted to decode scanlines, they had to
create an SkCodec in order to get an SkScanlineDecoder. This introduces
complications if input data is not easily shared between the two
objects.
Instead, add methods to SkScanlineDecoder for creating a new one from
input data, and remove the creation functions from SkCodec.
Update DM and tests.
Review URL: https://codereview.chromium.org/1267583002
