diff options
Diffstat (limited to 'chromium/components/webp_transcode/webp_decoder.mm')
| -rw-r--r-- | chromium/components/webp_transcode/webp_decoder.mm | 252 |
1 files changed, 0 insertions, 252 deletions
diff --git a/chromium/components/webp_transcode/webp_decoder.mm b/chromium/components/webp_transcode/webp_decoder.mm deleted file mode 100644 index 38ae361e5d7..00000000000 --- a/chromium/components/webp_transcode/webp_decoder.mm +++ /dev/null @@ -1,252 +0,0 @@ -// Copyright 2013 The Chromium Authors. All rights reserved. -// Use of this source code is governed by a BSD-style license that can be -// found in the LICENSE file. - -#include "components/webp_transcode/webp_decoder.h" - -#import <Foundation/Foundation.h> -#include <stdint.h> -#import <UIKit/UIKit.h> - -#include "base/logging.h" -#include "base/metrics/histogram.h" - -namespace { - -const uint8_t kNumIfdEntries = 15; -const unsigned int kExtraDataSize = 16; -// 10b for signature/header + n * 12b entries + 4b for IFD terminator: -const unsigned int kExtraDataOffset = 10 + 12 * kNumIfdEntries + 4; -const unsigned int kHeaderSize = kExtraDataOffset + kExtraDataSize; -const int kRecompressionThreshold = 64 * 64; // Threshold in pixels. -const CGFloat kJpegQuality = 0.85; - -// Adapted from libwebp example dwebp.c. -void PutLE16(uint8_t* const dst, uint32_t value) { - dst[0] = (value >> 0) & 0xff; - dst[1] = (value >> 8) & 0xff; -} - -void PutLE32(uint8_t* const dst, uint32_t value) { - PutLE16(dst + 0, (value >> 0) & 0xffff); - PutLE16(dst + 2, (value >> 16) & 0xffff); -} - -void WriteTiffHeader(uint8_t* dst, - int width, - int height, - int bytes_per_px, - bool has_alpha) { - // For non-alpha case, we omit tag 0x152 (ExtraSamples). - const uint8_t num_ifd_entries = - has_alpha ? kNumIfdEntries : kNumIfdEntries - 1; - uint8_t tiff_header[kHeaderSize] = { - 0x49, 0x49, 0x2a, 0x00, // little endian signature - 8, 0, 0, 0, // offset to the unique IFD that follows - // IFD (offset = 8). Entries must be written in increasing tag order. - num_ifd_entries, 0, // Number of entries in the IFD (12 bytes each). - 0x00, 0x01, 3, 0, 1, 0, 0, 0, 0, 0, 0, 0, // 10: Width (TBD) - 0x01, 0x01, 3, 0, 1, 0, 0, 0, 0, 0, 0, 0, // 22: Height (TBD) - 0x02, 0x01, 3, 0, bytes_per_px, 0, 0, 0, // 34: BitsPerSample: 8888 - kExtraDataOffset + 0, 0, 0, 0, - 0x03, 0x01, 3, 0, 1, 0, 0, 0, 1, 0, 0, 0, // 46: Compression: none - 0x06, 0x01, 3, 0, 1, 0, 0, 0, 2, 0, 0, 0, // 58: Photometric: RGB - 0x11, 0x01, 4, 0, 1, 0, 0, 0, // 70: Strips offset: - kHeaderSize, 0, 0, 0, // data follows header - 0x12, 0x01, 3, 0, 1, 0, 0, 0, 1, 0, 0, 0, // 82: Orientation: topleft - 0x15, 0x01, 3, 0, 1, 0, 0, 0, // 94: SamplesPerPixels - bytes_per_px, 0, 0, 0, - 0x16, 0x01, 3, 0, 1, 0, 0, 0, 0, 0, 0, 0, // 106: Rows per strip (TBD) - 0x17, 0x01, 4, 0, 1, 0, 0, 0, 0, 0, 0, 0, // 118: StripByteCount (TBD) - 0x1a, 0x01, 5, 0, 1, 0, 0, 0, // 130: X-resolution - kExtraDataOffset + 8, 0, 0, 0, - 0x1b, 0x01, 5, 0, 1, 0, 0, 0, // 142: Y-resolution - kExtraDataOffset + 8, 0, 0, 0, - 0x1c, 0x01, 3, 0, 1, 0, 0, 0, 1, 0, 0, 0, // 154: PlanarConfiguration - 0x28, 0x01, 3, 0, 1, 0, 0, 0, 2, 0, 0, 0, // 166: ResolutionUnit (inch) - 0x52, 0x01, 3, 0, 1, 0, 0, 0, 1, 0, 0, 0, // 178: ExtraSamples: rgbA - 0, 0, 0, 0, // 190: IFD terminator - // kExtraDataOffset: - 8, 0, 8, 0, 8, 0, 8, 0, // BitsPerSample - 72, 0, 0, 0, 1, 0, 0, 0 // 72 pixels/inch, for X/Y-resolution - }; - - // Fill placeholders in IFD: - PutLE32(tiff_header + 10 + 8, width); - PutLE32(tiff_header + 22 + 8, height); - PutLE32(tiff_header + 106 + 8, height); - PutLE32(tiff_header + 118 + 8, width * bytes_per_px * height); - if (!has_alpha) - PutLE32(tiff_header + 178, 0); - - memcpy(dst, tiff_header, kHeaderSize); -} - -} // namespace - -namespace webp_transcode { - -// static -size_t WebpDecoder::GetHeaderSize() { - return kHeaderSize; -} - -WebpDecoder::WebpDecoder(WebpDecoder::Delegate* delegate) - : delegate_(delegate), state_(READING_FEATURES), has_alpha_(0) { - DCHECK(delegate_.get()); - const bool rv = WebPInitDecoderConfig(&config_); - DCHECK(rv); -} - -WebpDecoder::~WebpDecoder() { - WebPFreeDecBuffer(&config_.output); -} - -void WebpDecoder::OnDataReceived(const base::scoped_nsobject<NSData>& data) { - DCHECK(data); - switch (state_) { - case READING_FEATURES: - DoReadFeatures(data); - break; - case READING_DATA: - DoReadData(data); - break; - case DONE: - DLOG(WARNING) << "Received WebP data but decoding is finished. Ignoring."; - break; - } -} - -void WebpDecoder::Stop() { - if (state_ != DONE) { - state_ = DONE; - DLOG(WARNING) << "Unexpected end of WebP data."; - delegate_->OnFinishedDecoding(false); - } -} - -void WebpDecoder::DoReadFeatures(NSData* data) { - DCHECK_EQ(READING_FEATURES, state_); - DCHECK(data); - if (features_) - [features_ appendData:data]; - else - features_.reset([[NSMutableData alloc] initWithData:data]); - VP8StatusCode status = - WebPGetFeatures(static_cast<const uint8_t*>([features_ bytes]), - [features_ length], &config_.input); - switch (status) { - case VP8_STATUS_OK: { - has_alpha_ = config_.input.has_alpha; - const uint32_t width = config_.input.width; - const uint32_t height = config_.input.height; - const size_t bytes_per_px = has_alpha_ ? 4 : 3; - const int stride = bytes_per_px * width; - const size_t image_data_size = stride * height; - const size_t total_size = image_data_size + kHeaderSize; - // Force pre-multiplied alpha. - config_.output.colorspace = has_alpha_ ? MODE_rgbA : MODE_RGB; - config_.output.u.RGBA.stride = stride; - // Create the output buffer. - config_.output.u.RGBA.size = image_data_size; - uint8_t* dst = static_cast<uint8_t*>(malloc(total_size)); - if (!dst) { - DLOG(ERROR) << "Could not allocate WebP decoding buffer (size = " - << total_size << ")."; - delegate_->OnFinishedDecoding(false); - state_ = DONE; - break; - } - WriteTiffHeader(dst, width, height, bytes_per_px, has_alpha_); - output_buffer_.reset([[NSData alloc] initWithBytesNoCopy:dst - length:total_size - freeWhenDone:YES]); - config_.output.is_external_memory = 1; - config_.output.u.RGBA.rgba = dst + kHeaderSize; - // Start decoding. - state_ = READING_DATA; - incremental_decoder_.reset(WebPINewDecoder(&config_.output)); - DoReadData(features_); - features_.reset(); - break; - } - case VP8_STATUS_NOT_ENOUGH_DATA: - // Do nothing. - break; - default: - DLOG(ERROR) << "Error in WebP image features."; - delegate_->OnFinishedDecoding(false); - state_ = DONE; - break; - } -} - -void WebpDecoder::DoReadData(NSData* data) { - DCHECK_EQ(READING_DATA, state_); - DCHECK(incremental_decoder_); - DCHECK(data); - VP8StatusCode status = - WebPIAppend(incremental_decoder_.get(), - static_cast<const uint8_t*>([data bytes]), [data length]); - switch (status) { - case VP8_STATUS_SUSPENDED: - // Do nothing: re-compression to JPEG or PNG cannot be done incrementally. - // Wait for the whole image to be decoded. - break; - case VP8_STATUS_OK: { - bool rv = DoSendData(); - DLOG_IF(ERROR, !rv) << "Error in WebP image conversion."; - state_ = DONE; - delegate_->OnFinishedDecoding(rv); - break; - } - default: - DLOG(ERROR) << "Error in WebP image decoding."; - delegate_->OnFinishedDecoding(false); - state_ = DONE; - break; - } -} - -bool WebpDecoder::DoSendData() { - DCHECK_EQ(READING_DATA, state_); - int width, height; - uint8_t* data_ptr = WebPIDecGetRGB(incremental_decoder_.get(), nullptr, - &width, &height, nullptr); - if (!data_ptr) - return false; - DCHECK_EQ(static_cast<const uint8_t*>([output_buffer_ bytes]) + kHeaderSize, - data_ptr); - base::scoped_nsobject<NSData> result_data; - // When the WebP image is larger than |kRecompressionThreshold| it is - // compressed to JPEG or PNG. Otherwise, the uncompressed TIFF is used. - DecodedImageFormat format = TIFF; - if (width * height > kRecompressionThreshold) { - base::scoped_nsobject<UIImage> tiff_image( - [[UIImage alloc] initWithData:output_buffer_]); - if (!tiff_image) - return false; - // Compress to PNG if the image is transparent, JPEG otherwise. - // TODO(droger): Use PNG instead of JPEG if the WebP image is lossless. - if (has_alpha_) { - result_data.reset([UIImagePNGRepresentation(tiff_image) retain]); - format = PNG; - } else { - result_data.reset( - [UIImageJPEGRepresentation(tiff_image, kJpegQuality) retain]); - format = JPEG; - } - if (!result_data) - return false; - } else { - result_data.reset([output_buffer_ retain]); - } - UMA_HISTOGRAM_ENUMERATION("WebP.DecodedImageFormat", format, - DECODED_FORMAT_COUNT); - delegate_->SetImageFeatures([result_data length], format); - delegate_->OnDataDecoded(result_data); - output_buffer_.reset(); - return true; -} - -} // namespace webp_transcode |