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authorJuan Linietsky <reduzio@gmail.com>2014-02-09 22:10:30 -0300
committerJuan Linietsky <reduzio@gmail.com>2014-02-09 22:10:30 -0300
commit0b806ee0fc9097fa7bda7ac0109191c9c5e0a1ac (patch)
tree276c4d099e178eb67fbd14f61d77b05e3808e9e3 /drivers/webp/dec/webpi.h
parent0e49da1687bc8192ed210947da52c9e5c5f301bb (diff)
GODOT IS OPEN SOURCE
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+// Copyright 2011 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+// Internal header: WebP decoding parameters and custom IO on buffer
+//
+// Author: somnath@google.com (Somnath Banerjee)
+
+#ifndef WEBP_DEC_WEBPI_H_
+#define WEBP_DEC_WEBPI_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "../utils/rescaler.h"
+#include "./decode_vp8.h"
+
+//------------------------------------------------------------------------------
+// WebPDecParams: Decoding output parameters. Transient internal object.
+
+typedef struct WebPDecParams WebPDecParams;
+typedef int (*OutputFunc)(const VP8Io* const io, WebPDecParams* const p);
+typedef int (*OutputRowFunc)(WebPDecParams* const p, int y_pos);
+
+struct WebPDecParams {
+ WebPDecBuffer* output; // output buffer.
+ uint8_t* tmp_y, *tmp_u, *tmp_v; // cache for the fancy upsampler
+ // or used for tmp rescaling
+
+ int last_y; // coordinate of the line that was last output
+ const WebPDecoderOptions* options; // if not NULL, use alt decoding features
+ // rescalers
+ WebPRescaler scaler_y, scaler_u, scaler_v, scaler_a;
+ void* memory; // overall scratch memory for the output work.
+
+ OutputFunc emit; // output RGB or YUV samples
+ OutputFunc emit_alpha; // output alpha channel
+ OutputRowFunc emit_alpha_row; // output one line of rescaled alpha values
+};
+
+// Should be called first, before any use of the WebPDecParams object.
+void WebPResetDecParams(WebPDecParams* const params);
+
+//------------------------------------------------------------------------------
+// Header parsing helpers
+
+// Structure storing a description of the RIFF headers.
+typedef struct {
+ const uint8_t* data; // input buffer
+ size_t data_size; // input buffer size
+ size_t offset; // offset to main data chunk (VP8 or VP8L)
+ const uint8_t* alpha_data; // points to alpha chunk (if present)
+ size_t alpha_data_size; // alpha chunk size
+ size_t compressed_size; // VP8/VP8L compressed data size
+ size_t riff_size; // size of the riff payload (or 0 if absent)
+ int is_lossless; // true if a VP8L chunk is present
+} WebPHeaderStructure;
+
+// Skips over all valid chunks prior to the first VP8/VP8L frame header.
+// Returns: VP8_STATUS_OK, VP8_STATUS_BITSTREAM_ERROR (invalid header/chunk),
+// VP8_STATUS_NOT_ENOUGH_DATA (partial input) or VP8_STATUS_UNSUPPORTED_FEATURE
+// in the case of non-decodable features (animation for instance).
+// In 'headers', compressed_size, offset, alpha_data, alpha_size, and lossless
+// fields are updated appropriately upon success.
+VP8StatusCode WebPParseHeaders(WebPHeaderStructure* const headers);
+
+//------------------------------------------------------------------------------
+// Misc utils
+
+// Initializes VP8Io with custom setup, io and teardown functions. The default
+// hooks will use the supplied 'params' as io->opaque handle.
+void WebPInitCustomIo(WebPDecParams* const params, VP8Io* const io);
+
+// Setup crop_xxx fields, mb_w and mb_h in io. 'src_colorspace' refers
+// to the *compressed* format, not the output one.
+int WebPIoInitFromOptions(const WebPDecoderOptions* const options,
+ VP8Io* const io, WEBP_CSP_MODE src_colorspace);
+
+//------------------------------------------------------------------------------
+// Internal functions regarding WebPDecBuffer memory (in buffer.c).
+// Don't really need to be externally visible for now.
+
+// Prepare 'buffer' with the requested initial dimensions width/height.
+// If no external storage is supplied, initializes buffer by allocating output
+// memory and setting up the stride information. Validate the parameters. Return
+// an error code in case of problem (no memory, or invalid stride / size /
+// dimension / etc.). If *options is not NULL, also verify that the options'
+// parameters are valid and apply them to the width/height dimensions of the
+// output buffer. This takes cropping / scaling / rotation into account.
+VP8StatusCode WebPAllocateDecBuffer(int width, int height,
+ const WebPDecoderOptions* const options,
+ WebPDecBuffer* const buffer);
+
+// Copy 'src' into 'dst' buffer, making sure 'dst' is not marked as owner of the
+// memory (still held by 'src').
+void WebPCopyDecBuffer(const WebPDecBuffer* const src,
+ WebPDecBuffer* const dst);
+
+// Copy and transfer ownership from src to dst (beware of parameter order!)
+void WebPGrabDecBuffer(WebPDecBuffer* const src, WebPDecBuffer* const dst);
+
+
+
+//------------------------------------------------------------------------------
+
+#ifdef __cplusplus
+} // extern "C"
+#endif
+
+#endif /* WEBP_DEC_WEBPI_H_ */