Use demux API in SkWebpCodec
* Necessary to read ICC profiles
* Will be necessary to implement animation
* Requires consolidated data with length
Doesn't affect decode performance (thought I believe
our performance tests only cover SkStreams with memory
bases).
BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2311793004
Review-Url: https://codereview.chromium.org/2311793004
diff --git a/src/codec/SkWebpCodec.cpp b/src/codec/SkWebpCodec.cpp
index c28d077..c12b1df 100644
--- a/src/codec/SkWebpCodec.cpp
+++ b/src/codec/SkWebpCodec.cpp
@@ -7,6 +7,7 @@
#include "SkCodecPriv.h"
#include "SkWebpCodec.h"
+#include "SkStreamPriv.h"
#include "SkTemplates.h"
// A WebP decoder on top of (subset of) libwebp
@@ -36,26 +37,55 @@
SkCodec* SkWebpCodec::NewFromStream(SkStream* stream) {
SkAutoTDelete<SkStream> streamDeleter(stream);
- unsigned char buffer[WEBP_VP8_HEADER_SIZE];
- SkASSERT(WEBP_VP8_HEADER_SIZE <= SkCodec::MinBufferedBytesNeeded());
+ // Webp demux needs a contiguous data buffer.
+ sk_sp<SkData> data = nullptr;
+ if (stream->getMemoryBase()) {
+ // It is safe to make without copy because we'll hold onto the stream.
+ data = SkData::MakeWithoutCopy(stream->getMemoryBase(), stream->getLength());
+ } else {
+ data = SkCopyStreamToData(stream);
- const size_t bytesPeeked = stream->peek(buffer, WEBP_VP8_HEADER_SIZE);
- if (bytesPeeked != WEBP_VP8_HEADER_SIZE) {
- // Use read + rewind as a backup
- if (stream->read(buffer, WEBP_VP8_HEADER_SIZE) != WEBP_VP8_HEADER_SIZE
- || !stream->rewind())
+ // If we are forced to copy the stream to a data, we can go ahead and delete the stream.
+ streamDeleter.reset(nullptr);
+ }
+
+ // It's a little strange that the |demux| will outlive |webpData|, though it needs the
+ // pointer in |webpData| to remain valid. This works because the pointer remains valid
+ // until the SkData is freed.
+ WebPData webpData = { data->bytes(), data->size() };
+ SkAutoTCallVProc<WebPDemuxer, WebPDemuxDelete> demux(WebPDemuxPartial(&webpData, nullptr));
+ if (nullptr == demux) {
return nullptr;
}
- WebPBitstreamFeatures features;
- VP8StatusCode status = WebPGetFeatures(buffer, WEBP_VP8_HEADER_SIZE, &features);
- if (VP8_STATUS_OK != status) {
- return nullptr; // Invalid WebP file.
+ WebPChunkIterator chunkIterator;
+ SkAutoTCallVProc<WebPChunkIterator, WebPDemuxReleaseChunkIterator> autoCI(&chunkIterator);
+ sk_sp<SkColorSpace> colorSpace = nullptr;
+ if (WebPDemuxGetChunk(demux, "ICCP", 1, &chunkIterator)) {
+ colorSpace = SkColorSpace::NewICC(chunkIterator.chunk.bytes, chunkIterator.chunk.size);
}
- // sanity check for image size that's about to be decoded.
+ if (!colorSpace) {
+ colorSpace = SkColorSpace::NewNamed(SkColorSpace::kSRGB_Named);
+ }
+
+ // Since we do not yet support animation, we get the |width|, |height|, |color|, and |alpha|
+ // from the first frame. It's the only frame we will decode.
+ //
+ // TODO:
+ // When we support animation, we'll want to report the canvas width and canvas height instead.
+ // We can get these from the |demux| directly.
+ // What |color| and |alpha| will we want to report though? WebP allows different frames
+ // to be encoded in different ways, making the encoded format difficult to describe.
+ WebPIterator frame;
+ SkAutoTCallVProc<WebPIterator, WebPDemuxReleaseIterator> autoFrame(&frame);
+ if (!WebPDemuxGetFrame(demux, 1, &frame)) {
+ return nullptr;
+ }
+
+ // Sanity check for image size that's about to be decoded.
{
- const int64_t size = sk_64_mul(features.width, features.height);
+ const int64_t size = sk_64_mul(frame.width, frame.height);
if (!sk_64_isS32(size)) {
return nullptr;
}
@@ -65,6 +95,16 @@
}
}
+ // TODO:
+ // The only reason we actually need to call WebPGetFeatures() is to get the |features.format|.
+ // This call actually re-reads the frame header. Should we suggest that libwebp expose
+ // the format on the |frame|?
+ WebPBitstreamFeatures features;
+ VP8StatusCode status = WebPGetFeatures(frame.fragment.bytes, frame.fragment.size, &features);
+ if (VP8_STATUS_OK != status) {
+ return nullptr;
+ }
+
SkEncodedInfo::Color color;
SkEncodedInfo::Alpha alpha;
switch (features.format) {
@@ -98,30 +138,9 @@
return nullptr;
}
- // FIXME (msarett):
- // Temporary strategy for getting ICC profiles from webps. Once the incremental decoding
- // API lands, we will use the WebPDemuxer to manage the entire decode.
- sk_sp<SkColorSpace> colorSpace = nullptr;
- const void* memory = stream->getMemoryBase();
- if (memory) {
- WebPData data = { (const uint8_t*) memory, stream->getLength() };
- WebPDemuxState state;
- SkAutoTCallVProc<WebPDemuxer, WebPDemuxDelete> demux(WebPDemuxPartial(&data, &state));
-
- WebPChunkIterator chunkIterator;
- SkAutoTCallVProc<WebPChunkIterator, WebPDemuxReleaseChunkIterator> autoCI(&chunkIterator);
- if (demux && WebPDemuxGetChunk(demux, "ICCP", 1, &chunkIterator)) {
- colorSpace = SkColorSpace::NewICC(chunkIterator.chunk.bytes, chunkIterator.chunk.size);
- }
- }
-
- if (!colorSpace) {
- colorSpace = SkColorSpace::NewNamed(SkColorSpace::kSRGB_Named);
- }
-
SkEncodedInfo info = SkEncodedInfo::Make(color, alpha, 8);
- return new SkWebpCodec(features.width, features.height, info, colorSpace,
- streamDeleter.release());
+ return new SkWebpCodec(features.width, features.height, info, std::move(colorSpace),
+ streamDeleter.release(), demux.release(), std::move(data));
}
// This version is slightly different from SkCodecPriv's version of conversion_possible. It
@@ -158,7 +177,6 @@
&& dim.height() >= 1 && dim.height() <= info.height();
}
-
static WEBP_CSP_MODE webp_decode_mode(SkColorType ct, bool premultiply) {
switch (ct) {
case kBGRA_8888_SkColorType:
@@ -172,11 +190,6 @@
}
}
-// The WebP decoding API allows us to incrementally pass chunks of bytes as we receive them to the
-// decoder with WebPIAppend. In order to do so, we need to read chunks from the SkStream. This size
-// is arbitrary.
-static const size_t BUFFER_SIZE = 4096;
-
bool SkWebpCodec::onGetValidSubset(SkIRect* desiredSubset) const {
if (!desiredSubset) {
return false;
@@ -263,33 +276,31 @@
config.output.u.RGBA.size = dstInfo.getSafeSize(rowBytes);
config.output.is_external_memory = 1;
+ WebPIterator frame;
+ SkAutoTCallVProc<WebPIterator, WebPDemuxReleaseIterator> autoFrame(&frame);
+ // If this succeeded in NewFromStream(), it should succeed again here.
+ SkAssertResult(WebPDemuxGetFrame(fDemux, 1, &frame));
+
SkAutoTCallVProc<WebPIDecoder, WebPIDelete> idec(WebPIDecode(nullptr, 0, &config));
if (!idec) {
return kInvalidInput;
}
- SkAutoTMalloc<uint8_t> storage(BUFFER_SIZE);
- uint8_t* buffer = storage.get();
- while (true) {
- const size_t bytesRead = stream()->read(buffer, BUFFER_SIZE);
- if (0 == bytesRead) {
- WebPIDecGetRGB(idec, rowsDecoded, NULL, NULL, NULL);
+ switch (WebPIUpdate(idec, frame.fragment.bytes, frame.fragment.size)) {
+ case VP8_STATUS_OK:
+ return kSuccess;
+ case VP8_STATUS_SUSPENDED:
+ WebPIDecGetRGB(idec, rowsDecoded, nullptr, nullptr, nullptr);
return kIncompleteInput;
- }
-
- switch (WebPIAppend(idec, buffer, bytesRead)) {
- case VP8_STATUS_OK:
- return kSuccess;
- case VP8_STATUS_SUSPENDED:
- // Break out of the switch statement. Continue the loop.
- break;
- default:
- return kInvalidInput;
- }
+ default:
+ return kInvalidInput;
}
}
SkWebpCodec::SkWebpCodec(int width, int height, const SkEncodedInfo& info,
- sk_sp<SkColorSpace> colorSpace, SkStream* stream)
- : INHERITED(width, height, info, stream, colorSpace)
+ sk_sp<SkColorSpace> colorSpace, SkStream* stream, WebPDemuxer* demux,
+ sk_sp<SkData> data)
+ : INHERITED(width, height, info, stream, std::move(colorSpace))
+ , fDemux(demux)
+ , fData(std::move(data))
{}