Index: third_party/libwebp/utils/rescaler.h |
diff --git a/third_party/libwebp/utils/rescaler.h b/third_party/libwebp/utils/rescaler.h |
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index 0000000000000000000000000000000000000000..ef93d465f09b605a9181ea14b9e665d6d40f0e65 |
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+// Copyright 2012 Google Inc. All Rights Reserved. |
+// |
+// This code is licensed under the same terms as WebM: |
+// Software License Agreement: http://www.webmproject.org/license/software/ |
+// Additional IP Rights Grant: http://www.webmproject.org/license/additional/ |
+// ----------------------------------------------------------------------------- |
+// |
+// Rescaling functions |
+// |
+// Author: Skal (pascal.massimino@gmail.com) |
+ |
+#ifndef WEBP_UTILS_RESCALER_H_ |
+#define WEBP_UTILS_RESCALER_H_ |
+ |
+#if defined(__cplusplus) || defined(c_plusplus) |
+extern "C" { |
+#endif |
+ |
+#include "../webp/types.h" |
+ |
+// Structure used for on-the-fly rescaling |
+typedef struct { |
+ int x_expand; // true if we're expanding in the x direction |
+ int num_channels; // bytes to jump between pixels |
+ int fy_scale, fx_scale; // fixed-point scaling factor |
+ int64_t fxy_scale; // '' |
+ // we need hpel-precise add/sub increments, for the downsampled U/V planes. |
+ int y_accum; // vertical accumulator |
+ int y_add, y_sub; // vertical increments (add ~= src, sub ~= dst) |
+ int x_add, x_sub; // horizontal increments (add ~= src, sub ~= dst) |
+ int src_width, src_height; // source dimensions |
+ int dst_width, dst_height; // destination dimensions |
+ uint8_t* dst; |
+ int dst_stride; |
+ int32_t* irow, *frow; // work buffer |
+} WebPRescaler; |
+ |
+// Initialize a rescaler given scratch area 'work' and dimensions of src & dst. |
+void WebPRescalerInit(WebPRescaler* const wrk, int src_width, int src_height, |
+ uint8_t* const dst, |
+ int dst_width, int dst_height, int dst_stride, |
+ int num_channels, |
+ int x_add, int x_sub, |
+ int y_add, int y_sub, |
+ int32_t* const work); |
+ |
+// Import a row of data and save its contribution in the rescaler. |
+// 'channel' denotes the channel number to be imported. |
+void WebPRescalerImportRow(WebPRescaler* const rescaler, |
+ const uint8_t* const src, int channel); |
+ |
+// Import multiple rows over all channels, until at least one row is ready to |
+// be exported. Returns the actual number of lines that were imported. |
+int WebPRescalerImport(WebPRescaler* const rescaler, int num_rows, |
+ const uint8_t* src, int src_stride); |
+ |
+// Return true if there is pending output rows ready. |
+static WEBP_INLINE |
+int WebPRescalerHasPendingOutput(const WebPRescaler* const rescaler) { |
+ return (rescaler->y_accum <= 0); |
+} |
+ |
+// Export one row from rescaler. Returns the pointer where output was written, |
+// or NULL if no row was pending. |
+uint8_t* WebPRescalerExportRow(WebPRescaler* const wrk); |
+ |
+// Export as many rows as possible. Return the numbers of rows written. |
+int WebPRescalerExport(WebPRescaler* const wrk); |
+ |
+//------------------------------------------------------------------------------ |
+ |
+#if defined(__cplusplus) || defined(c_plusplus) |
+} // extern "C" |
+#endif |
+ |
+#endif /* WEBP_UTILS_RESCALER_H_ */ |