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90516ae8f5
so we can add few fields without breaking ABI + re-order fields + refresh the doc Change-Id: Id60ec33934f6346e35c95fcdb4abbe1bc7b50acb
604 lines
25 KiB
C
604 lines
25 KiB
C
// Copyright 2011 Google Inc. All Rights Reserved.
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//
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// This code is licensed under the same terms as WebM:
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// Software License Agreement: http://www.webmproject.org/license/software/
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// Additional IP Rights Grant: http://www.webmproject.org/license/additional/
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// -----------------------------------------------------------------------------
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//
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// RIFF container manipulation for WEBP images.
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//
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// Authors: Urvang (urvang@google.com)
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// Vikas (vikasa@google.com)
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// This API allows manipulation of WebP container images containing features
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// like Color profile, XMP metadata, Animation and Tiling.
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//
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// Code Example#1: Creating a MUX with image data, color profile and XMP
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// metadata.
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//
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// int copy_data = 0;
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// WebPMux* mux = WebPMuxNew();
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// // ... (Prepare image data).
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// WebPMuxSetImage(mux, &image, copy_data);
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// // ... (Prepare ICCP color profile data).
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// WebPMuxSetColorProfile(mux, &icc_profile, copy_data);
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// // ... (Prepare XMP metadata).
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// WebPMuxSetMetadata(mux, &xmp, copy_data);
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// // Get data from mux in WebP RIFF format.
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// WebPMuxAssemble(mux, &output_data);
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// WebPMuxDelete(mux);
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// // ... (Consume output_data; e.g. write output_data.bytes_ to file).
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// WebPDataClear(&output_data);
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//
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// Code Example#2: Get image and color profile data from a WebP file.
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//
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// int copy_data = 0;
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// // ... (Read data from file).
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// WebPMux* mux = WebPMuxCreate(&data, copy_data);
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// WebPMuxGetImage(mux, &image);
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// // ... (Consume image; e.g. call WebPDecode() to decode the data).
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// WebPMuxGetColorProfile(mux, &icc_profile);
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// // ... (Consume icc_data).
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// WebPMuxDelete(mux);
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// free(data);
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#ifndef WEBP_WEBP_MUX_H_
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#define WEBP_WEBP_MUX_H_
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#include "./types.h"
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#if defined(__cplusplus) || defined(c_plusplus)
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extern "C" {
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#endif
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#define WEBP_MUX_ABI_VERSION 0x0100 // MAJOR(8b) + MINOR(8b)
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// Error codes
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typedef enum {
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WEBP_MUX_OK = 1,
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WEBP_MUX_ERROR = 0,
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WEBP_MUX_NOT_FOUND = -1,
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WEBP_MUX_INVALID_ARGUMENT = -2,
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WEBP_MUX_INVALID_PARAMETER = -3,
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WEBP_MUX_BAD_DATA = -4,
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WEBP_MUX_MEMORY_ERROR = -5,
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WEBP_MUX_NOT_ENOUGH_DATA = -6
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} WebPMuxError;
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// Flag values for different features used in VP8X chunk.
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typedef enum {
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TILE_FLAG = 0x00000001,
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ANIMATION_FLAG = 0x00000002,
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ICCP_FLAG = 0x00000004,
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META_FLAG = 0x00000008,
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ALPHA_FLAG = 0x00000010
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} WebPFeatureFlags;
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// IDs for different types of chunks.
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typedef enum {
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WEBP_CHUNK_VP8X, // VP8X
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WEBP_CHUNK_ICCP, // ICCP
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WEBP_CHUNK_LOOP, // LOOP
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WEBP_CHUNK_FRAME, // FRM
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WEBP_CHUNK_TILE, // TILE
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WEBP_CHUNK_ALPHA, // ALPH
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WEBP_CHUNK_IMAGE, // VP8/VP8L
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WEBP_CHUNK_META, // META
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WEBP_CHUNK_UNKNOWN, // Other chunks.
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WEBP_CHUNK_NIL
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} WebPChunkId;
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typedef struct WebPMux WebPMux; // main opaque object.
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// Data type used to describe 'raw' data, e.g., chunk data
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// (ICC profile, metadata) and WebP compressed image data.
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typedef struct {
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const uint8_t* bytes_;
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size_t size_;
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} WebPData;
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//------------------------------------------------------------------------------
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// Manipulation of a WebPData object.
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// Clears the contents of the 'webp_data' object by calling free(). Does not
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// deallocate the object itself.
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WEBP_EXTERN(void) WebPDataClear(WebPData* webp_data);
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// Allocates necessary storage for 'dst' and copies the contents of 'src'.
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// Returns true on success.
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WEBP_EXTERN(int) WebPDataCopy(const WebPData* src, WebPData* dst);
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//------------------------------------------------------------------------------
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// Life of a Mux object
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// Internal, version-checked, entry point
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WEBP_EXTERN(WebPMux*) WebPNewInternal(int);
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// Creates an empty mux object.
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// Returns:
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// A pointer to the newly created empty mux object.
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static WEBP_INLINE WebPMux* WebPMuxNew(void) {
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return WebPNewInternal(WEBP_MUX_ABI_VERSION);
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}
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// Deletes the mux object.
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// Parameters:
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// mux - (in/out) object to be deleted
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WEBP_EXTERN(void) WebPMuxDelete(WebPMux* mux);
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//------------------------------------------------------------------------------
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// Mux creation.
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// Internal, version-checked, entry point
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WEBP_EXTERN(WebPMux*) WebPMuxCreateInternal(const WebPData*, int, int);
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// Creates a mux object from raw data given in WebP RIFF format.
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// Parameters:
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// bitstream - (in) the bitstream data in WebP RIFF format
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// copy_data - (in) value 1 indicates given data WILL copied to the mux, and
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// value 0 indicates data will NOT be copied.
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// Returns:
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// A pointer to the mux object created from given data - on success.
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// NULL - In case of invalid data or memory error.
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static WEBP_INLINE WebPMux* WebPMuxCreate(const WebPData* bitstream,
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int copy_data) {
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return WebPMuxCreateInternal(bitstream, copy_data, WEBP_MUX_ABI_VERSION);
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}
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//------------------------------------------------------------------------------
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// Single Image.
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// Sets the image in the mux object. Any existing images (including frame/tile)
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// will be removed.
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// Parameters:
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// mux - (in/out) object in which the image is to be set
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// bitstream - (in) can either be a raw VP8/VP8L bitstream or a single-image
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// WebP file (non-animated and non-tiled)
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// copy_data - (in) value 1 indicates given data WILL copied to the mux, and
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// value 0 indicates data will NOT be copied.
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// Returns:
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// WEBP_MUX_INVALID_ARGUMENT - if mux is NULL or bitstream is NULL.
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// WEBP_MUX_MEMORY_ERROR - on memory allocation error.
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// WEBP_MUX_OK - on success.
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WEBP_EXTERN(WebPMuxError) WebPMuxSetImage(WebPMux* mux,
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const WebPData* bitstream,
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int copy_data);
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// Gets image data from the mux object.
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// The content of 'bitstream' is allocated using malloc(), and NOT
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// owned by the 'mux' object. It MUST be deallocated by the caller by calling
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// WebPDataClear().
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// Parameters:
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// mux - (in) object from which the image is to be fetched
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// bitstream - (out) the image data
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// Returns:
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// WEBP_MUX_INVALID_ARGUMENT - if either mux or bitstream is NULL
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// OR mux contains animation/tiling.
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// WEBP_MUX_NOT_FOUND - if image is not present in mux object.
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// WEBP_MUX_OK - on success.
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WEBP_EXTERN(WebPMuxError) WebPMuxGetImage(const WebPMux* mux,
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WebPData* bitstream);
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// Deletes the image in the mux object.
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// Parameters:
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// mux - (in/out) object from which the image is to be deleted
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// Returns:
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// WEBP_MUX_INVALID_ARGUMENT - if mux is NULL
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// OR if mux contains animation/tiling.
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// WEBP_MUX_NOT_FOUND - if image is not present in mux object.
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// WEBP_MUX_OK - on success.
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WEBP_EXTERN(WebPMuxError) WebPMuxDeleteImage(WebPMux* mux);
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//------------------------------------------------------------------------------
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// XMP Metadata.
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// Sets the XMP metadata in the mux object. Any existing metadata chunk(s) will
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// be removed.
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// Parameters:
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// mux - (in/out) object to which the XMP metadata is to be added
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// metadata - (in) the XMP metadata data to be added
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// copy_data - (in) value 1 indicates given data WILL copied to the mux, and
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// value 0 indicates data will NOT be copied.
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// Returns:
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// WEBP_MUX_INVALID_ARGUMENT - if mux or metadata is NULL.
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// WEBP_MUX_MEMORY_ERROR - on memory allocation error.
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// WEBP_MUX_OK - on success.
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WEBP_EXTERN(WebPMuxError) WebPMuxSetMetadata(WebPMux* mux,
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const WebPData* metadata,
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int copy_data);
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// Gets a reference to the XMP metadata in the mux object.
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// The caller should NOT free the returned data.
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// Parameters:
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// mux - (in) object from which the XMP metadata is to be fetched
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// metadata - (out) XMP metadata
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// Returns:
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// WEBP_MUX_INVALID_ARGUMENT - if either mux or metadata is NULL.
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// WEBP_MUX_NOT_FOUND - if metadata is not present in mux object.
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// WEBP_MUX_OK - on success.
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WEBP_EXTERN(WebPMuxError) WebPMuxGetMetadata(const WebPMux* mux,
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WebPData* metadata);
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// Deletes the XMP metadata in the mux object.
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// Parameters:
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// mux - (in/out) object from which XMP metadata is to be deleted
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// Returns:
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// WEBP_MUX_INVALID_ARGUMENT - if mux is NULL
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// WEBP_MUX_NOT_FOUND - If mux does not contain metadata.
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// WEBP_MUX_OK - on success.
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WEBP_EXTERN(WebPMuxError) WebPMuxDeleteMetadata(WebPMux* mux);
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//------------------------------------------------------------------------------
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// ICC Color Profile.
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// Sets the color profile in the mux object. Any existing color profile chunk(s)
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// will be removed.
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// Parameters:
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// mux - (in/out) object to which the color profile is to be added
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// color_profile - (in) the color profile data to be added
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// copy_data - (in) value 1 indicates given data WILL copied to the mux, and
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// value 0 indicates data will NOT be copied.
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// Returns:
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// WEBP_MUX_INVALID_ARGUMENT - if mux or color_profile is NULL
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// WEBP_MUX_MEMORY_ERROR - on memory allocation error
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// WEBP_MUX_OK - on success
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WEBP_EXTERN(WebPMuxError) WebPMuxSetColorProfile(WebPMux* mux,
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const WebPData* color_profile,
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int copy_data);
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// Gets a reference to the color profile in the mux object.
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// The caller should NOT free the returned data.
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// Parameters:
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// mux - (in) object from which the color profile data is to be fetched
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// color_profile - (out) color profile data
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// Returns:
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// WEBP_MUX_INVALID_ARGUMENT - if either mux or color_profile is NULL.
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// WEBP_MUX_NOT_FOUND - if color profile is not present in mux object.
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// WEBP_MUX_OK - on success.
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WEBP_EXTERN(WebPMuxError) WebPMuxGetColorProfile(const WebPMux* mux,
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WebPData* color_profile);
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// Deletes the color profile in the mux object.
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// Parameters:
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// mux - (in/out) object from which color profile is to be deleted
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// Returns:
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// WEBP_MUX_INVALID_ARGUMENT - if mux is NULL
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// WEBP_MUX_NOT_FOUND - If mux does not contain color profile.
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// WEBP_MUX_OK - on success.
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WEBP_EXTERN(WebPMuxError) WebPMuxDeleteColorProfile(WebPMux* mux);
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//------------------------------------------------------------------------------
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// Animation.
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// Adds an animation frame at the end of the mux object.
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// Note: as WebP only supports even offsets, any odd offset will be snapped to
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// an even location using: offset &= ~1
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// Parameters:
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// mux - (in/out) object to which an animation frame is to be added
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// bitstream - (in) the image data corresponding to the frame. It can either
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// be a raw VP8/VP8L bitstream or a single-image WebP file
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// (non-animated and non-tiled)
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// x_offset - (in) x-offset of the frame to be added
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// y_offset - (in) y-offset of the frame to be added
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// duration - (in) duration of the frame to be added (in milliseconds)
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// copy_data - (in) value 1 indicates given data WILL copied to the mux, and
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// value 0 indicates data will NOT be copied.
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// Returns:
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// WEBP_MUX_INVALID_ARGUMENT - if mux is NULL or bitstream is NULL
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// WEBP_MUX_MEMORY_ERROR - on memory allocation error.
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// WEBP_MUX_OK - on success.
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WEBP_EXTERN(WebPMuxError) WebPMuxPushFrame(
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WebPMux* mux, const WebPData* bitstream,
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int x_offset, int y_offset, int duration, int copy_data);
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// TODO(urvang): Create a struct as follows to reduce argument list size:
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// typedef struct {
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// WebPData bitstream;
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// int x_offset, y_offset;
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// int duration;
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// } FrameInfo;
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// Gets the nth animation frame from the mux object.
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// The content of 'bitstream' is allocated using malloc(), and NOT
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// owned by the 'mux' object. It MUST be deallocated by the caller by calling
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// WebPDataClear().
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// nth=0 has a special meaning - last position.
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// Parameters:
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// mux - (in) object from which the info is to be fetched
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// nth - (in) index of the frame in the mux object
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// bitstream - (out) the image data
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// x_offset - (out) x-offset of the returned frame
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// y_offset - (out) y-offset of the returned frame
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// duration - (out) duration of the returned frame (in milliseconds)
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// Returns:
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// WEBP_MUX_INVALID_ARGUMENT - if either mux, bitstream, x_offset,
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// y_offset, or duration is NULL
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// WEBP_MUX_NOT_FOUND - if there are less than nth frames in the mux object.
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// WEBP_MUX_BAD_DATA - if nth frame chunk in mux is invalid.
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// WEBP_MUX_OK - on success.
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WEBP_EXTERN(WebPMuxError) WebPMuxGetFrame(
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const WebPMux* mux, uint32_t nth, WebPData* bitstream,
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int* x_offset, int* y_offset, int* duration);
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// Deletes an animation frame from the mux object.
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// nth=0 has a special meaning - last position.
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// Parameters:
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// mux - (in/out) object from which a frame is to be deleted
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// nth - (in) The position from which the frame is to be deleted
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// Returns:
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// WEBP_MUX_INVALID_ARGUMENT - if mux is NULL
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// WEBP_MUX_NOT_FOUND - If there are less than nth frames in the mux object
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// before deletion.
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// WEBP_MUX_OK - on success.
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WEBP_EXTERN(WebPMuxError) WebPMuxDeleteFrame(WebPMux* mux, uint32_t nth);
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// Sets the animation loop count in the mux object. Any existing loop count
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// value(s) will be removed.
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// Parameters:
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// mux - (in/out) object in which loop chunk is to be set/added
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// loop_count - (in) animation loop count value.
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// Note that loop_count of zero denotes infinite loop.
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// Returns:
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// WEBP_MUX_INVALID_ARGUMENT - if mux is NULL
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// WEBP_MUX_MEMORY_ERROR - on memory allocation error.
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// WEBP_MUX_OK - on success.
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WEBP_EXTERN(WebPMuxError) WebPMuxSetLoopCount(WebPMux* mux, int loop_count);
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// Gets the animation loop count from the mux object.
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// Parameters:
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// mux - (in) object from which the loop count is to be fetched
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// loop_count - (out) the loop_count value present in the LOOP chunk
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// Returns:
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// WEBP_MUX_INVALID_ARGUMENT - if either of mux or loop_count is NULL
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// WEBP_MUX_NOT_FOUND - if loop chunk is not present in mux object.
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// WEBP_MUX_OK - on success.
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WEBP_EXTERN(WebPMuxError) WebPMuxGetLoopCount(const WebPMux* mux,
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int* loop_count);
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//------------------------------------------------------------------------------
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// Tiling.
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// Adds a tile at the end of the mux object.
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// Note: as WebP only supports even offsets, any odd offset will be snapped to
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// an even location using: offset &= ~1
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// Parameters:
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// mux - (in/out) object to which a tile is to be added.
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// bitstream - (in) the image data corresponding to the frame. It can either
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// be a raw VP8/VP8L bitstream or a single-image WebP file
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// (non-animated and non-tiled)
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// x_offset - (in) x-offset of the tile to be added
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// y_offset - (in) y-offset of the tile to be added
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// copy_data - (in) value 1 indicates given data WILL copied to the mux, and
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// value 0 indicates data will NOT be copied.
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// Returns:
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// WEBP_MUX_INVALID_ARGUMENT - if mux is NULL or bitstream is NULL
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// WEBP_MUX_MEMORY_ERROR - on memory allocation error.
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// WEBP_MUX_OK - on success.
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WEBP_EXTERN(WebPMuxError) WebPMuxPushTile(
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WebPMux* mux, const WebPData* bitstream,
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int x_offset, int y_offset, int copy_data);
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// Gets the nth tile from the mux object.
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// The content of 'bitstream' is allocated using malloc(), and NOT
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// owned by the 'mux' object. It MUST be deallocated by the caller by calling
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// WebPDataClear().
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// nth=0 has a special meaning - last position.
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// Parameters:
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// mux - (in) object from which the info is to be fetched
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// nth - (in) index of the tile in the mux object
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// bitstream - (out) the image data
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// x_offset - (out) x-offset of the returned tile
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// y_offset - (out) y-offset of the returned tile
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// Returns:
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// WEBP_MUX_INVALID_ARGUMENT - if either mux, bitstream, x_offset or
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// y_offset is NULL
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// WEBP_MUX_NOT_FOUND - if there are less than nth tiles in the mux object.
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// WEBP_MUX_BAD_DATA - if nth tile chunk in mux is invalid.
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// WEBP_MUX_OK - on success.
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WEBP_EXTERN(WebPMuxError) WebPMuxGetTile(
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const WebPMux* mux, uint32_t nth, WebPData* bitstream,
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int* x_offset, int* y_offset);
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// Deletes a tile from the mux object.
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// nth=0 has a special meaning - last position
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// Parameters:
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// mux - (in/out) object from which a tile is to be deleted
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// nth - (in) The position from which the tile is to be deleted
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// Returns:
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// WEBP_MUX_INVALID_ARGUMENT - if mux is NULL
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// WEBP_MUX_NOT_FOUND - If there are less than nth tiles in the mux object
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// before deletion.
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// WEBP_MUX_OK - on success.
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WEBP_EXTERN(WebPMuxError) WebPMuxDeleteTile(WebPMux* mux, uint32_t nth);
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//------------------------------------------------------------------------------
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// Misc Utilities.
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// Gets the feature flags from the mux object.
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// Parameters:
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// mux - (in) object from which the features are to be fetched
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// flags - (out) the flags specifying which features are present in the
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// mux object. This will be an OR of various flag values.
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// Enum 'WebPFeatureFlags' can be used to test individual flag values.
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// Returns:
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// WEBP_MUX_INVALID_ARGUMENT - if mux or flags is NULL
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// WEBP_MUX_NOT_FOUND - if VP8X chunk is not present in mux object.
|
|
// WEBP_MUX_BAD_DATA - if VP8X chunk in mux is invalid.
|
|
// WEBP_MUX_OK - on success.
|
|
WEBP_EXTERN(WebPMuxError) WebPMuxGetFeatures(const WebPMux* mux,
|
|
uint32_t* flags);
|
|
|
|
// Gets number of chunks having tag value tag in the mux object.
|
|
// Parameters:
|
|
// mux - (in) object from which the info is to be fetched
|
|
// id - (in) chunk id specifying the type of chunk
|
|
// num_elements - (out) number of chunks with the given chunk id
|
|
// Returns:
|
|
// WEBP_MUX_INVALID_ARGUMENT - if either mux, or num_elements is NULL
|
|
// WEBP_MUX_OK - on success.
|
|
WEBP_EXTERN(WebPMuxError) WebPMuxNumChunks(const WebPMux* mux,
|
|
WebPChunkId id, int* num_elements);
|
|
|
|
// Assembles all chunks in WebP RIFF format and returns in 'assembled_data'.
|
|
// This function also validates the mux object.
|
|
// Note: The content of 'assembled_data' will be ignored and overwritten.
|
|
// Also, the content of 'assembled_data' is allocated using malloc(), and NOT
|
|
// owned by the 'mux' object. It MUST be deallocated by the caller by calling
|
|
// WebPDataClear().
|
|
// Parameters:
|
|
// mux - (in/out) object whose chunks are to be assembled
|
|
// assembled_data - (out) assembled WebP data
|
|
// Returns:
|
|
// WEBP_MUX_BAD_DATA - if mux object is invalid.
|
|
// WEBP_MUX_INVALID_ARGUMENT - if either mux, output_data or output_size is
|
|
// NULL.
|
|
// WEBP_MUX_MEMORY_ERROR - on memory allocation error.
|
|
// WEBP_MUX_OK - on success
|
|
WEBP_EXTERN(WebPMuxError) WebPMuxAssemble(WebPMux* mux,
|
|
WebPData* assembled_data);
|
|
|
|
//------------------------------------------------------------------------------
|
|
// Demux API.
|
|
// Enables extraction of image and extended format data from WebP files.
|
|
|
|
#define WEBP_DEMUX_ABI_VERSION 0x0100 // MAJOR(8b) + MINOR(8b)
|
|
|
|
typedef struct WebPDemuxer WebPDemuxer;
|
|
|
|
typedef enum {
|
|
WEBP_DEMUX_PARSING_HEADER, // Not enough data to parse full header.
|
|
WEBP_DEMUX_PARSED_HEADER, // Header parsing complete, data may be available.
|
|
WEBP_DEMUX_DONE // Entire file has been parsed.
|
|
} WebPDemuxState;
|
|
|
|
//------------------------------------------------------------------------------
|
|
// Life of a Demux object
|
|
|
|
// Internal, version-checked, entry point
|
|
WEBP_EXTERN(WebPDemuxer*) WebPDemuxInternal(
|
|
const WebPData*, int, WebPDemuxState*, int);
|
|
|
|
// Parses the WebP file given by 'data'.
|
|
// A complete WebP file must be present in 'data' for the function to succeed.
|
|
// Returns a WebPDemuxer object on successful parse, NULL otherwise.
|
|
static WEBP_INLINE WebPDemuxer* WebPDemux(const WebPData* data) {
|
|
return WebPDemuxInternal(data, 0, NULL, WEBP_DEMUX_ABI_VERSION);
|
|
}
|
|
|
|
// Parses the WebP file given by 'data'.
|
|
// If 'state' is non-NULL it will be set to indicate the status of the demuxer.
|
|
// Returns a WebPDemuxer object on successful parse, NULL otherwise.
|
|
static WEBP_INLINE WebPDemuxer* WebPDemuxPartial(
|
|
const WebPData* data, WebPDemuxState* state) {
|
|
return WebPDemuxInternal(data, 1, state, WEBP_DEMUX_ABI_VERSION);
|
|
}
|
|
|
|
// Frees memory associated with 'dmux'.
|
|
WEBP_EXTERN(void) WebPDemuxDelete(WebPDemuxer* dmux);
|
|
|
|
//------------------------------------------------------------------------------
|
|
// Data/information extraction.
|
|
|
|
typedef enum {
|
|
WEBP_FF_FORMAT_FLAGS, // Extended format flags present in the 'VP8X' chunk.
|
|
WEBP_FF_CANVAS_WIDTH,
|
|
WEBP_FF_CANVAS_HEIGHT,
|
|
WEBP_FF_LOOP_COUNT
|
|
} WebPFormatFeature;
|
|
|
|
// Get the 'feature' value from the 'dmux'.
|
|
// NOTE: values are only valid if WebPDemux() was used or WebPDemuxPartial()
|
|
// returned a state > WEBP_DEMUX_PARSING_HEADER.
|
|
WEBP_EXTERN(uint32_t) WebPDemuxGetI(
|
|
const WebPDemuxer* dmux, WebPFormatFeature feature);
|
|
|
|
//------------------------------------------------------------------------------
|
|
// Frame iteration.
|
|
|
|
typedef struct {
|
|
int frame_num_;
|
|
int num_frames_;
|
|
int tile_num_;
|
|
int num_tiles_;
|
|
int x_offset_, y_offset_; // offset relative to the canvas.
|
|
int width_, height_; // dimensions of this frame or tile.
|
|
int duration_; // display duration in milliseconds.
|
|
int complete_; // true if 'tile_' contains a full frame. partial images may
|
|
// still be decoded with the WebP incremental decoder.
|
|
WebPData tile_; // The frame or tile given by 'frame_num_' and 'tile_num_'.
|
|
|
|
uint32_t pad[4]; // padding for later use
|
|
void* private_;
|
|
} WebPIterator;
|
|
|
|
// Retrieves frame 'frame_number' from 'dmux'.
|
|
// 'iter->tile_' points to the first tile on return from this function.
|
|
// Individual tiles may be extracted using WebPDemuxSetTile().
|
|
// Setting 'frame_number' equal to 0 will return the last frame of the image.
|
|
// Returns false if 'dmux' is NULL or frame 'frame_number' is not present.
|
|
// Call WebPDemuxReleaseIterator() when use of the iterator is complete.
|
|
// NOTE: 'dmux' must persist for the lifetime of 'iter'.
|
|
WEBP_EXTERN(int) WebPDemuxGetFrame(
|
|
const WebPDemuxer* dmux, int frame_number, WebPIterator* iter);
|
|
|
|
// Sets 'iter->tile_' to point to the next ('iter->frame_num_' + 1) or previous
|
|
// ('iter->frame_num_' - 1) frame. These functions do not loop.
|
|
// Returns true on success, false otherwise.
|
|
WEBP_EXTERN(int) WebPDemuxNextFrame(WebPIterator* iter);
|
|
WEBP_EXTERN(int) WebPDemuxPrevFrame(WebPIterator* iter);
|
|
|
|
// Sets 'iter->tile_' to reflect tile number 'tile_number'.
|
|
// Returns true if tile 'tile_number' is present, false otherwise.
|
|
WEBP_EXTERN(int) WebPDemuxSelectTile(WebPIterator* iter, int tile_number);
|
|
|
|
// Releases any memory associated with 'iter'.
|
|
// Must be called before destroying the associated WebPDemuxer with
|
|
// WebPDemuxDelete().
|
|
WEBP_EXTERN(void) WebPDemuxReleaseIterator(WebPIterator* iter);
|
|
|
|
//------------------------------------------------------------------------------
|
|
// Chunk iteration.
|
|
|
|
typedef struct {
|
|
// The current and total number of chunks with the fourcc given to
|
|
// WebPDemuxGetChunk().
|
|
int chunk_num_;
|
|
int num_chunks_;
|
|
WebPData chunk_; // The payload of the chunk.
|
|
|
|
uint32_t pad[6]; // padding for later use
|
|
void* private_;
|
|
} WebPChunkIterator;
|
|
|
|
// Retrieves the 'chunk_number' instance of the chunk with id 'fourcc' from
|
|
// 'dmux'.
|
|
// 'fourcc' is a character array containing the fourcc of the chunk to return,
|
|
// e.g., "ICCP", "META", "EXIF", etc.
|
|
// Setting 'chunk_number' equal to 0 will return the last chunk in a set.
|
|
// Returns true if the chunk is found, false otherwise. Image related chunk
|
|
// payloads are accessed through WebPDemuxGetFrame() and related functions.
|
|
// Call WebPDemuxReleaseChunkIterator() when use of the iterator is complete.
|
|
// NOTE: 'dmux' must persist for the lifetime of the iterator.
|
|
WEBP_EXTERN(int) WebPDemuxGetChunk(const WebPDemuxer* dmux,
|
|
const char fourcc[4], int chunk_number,
|
|
WebPChunkIterator* iter);
|
|
|
|
// Sets 'iter->chunk_' to point to the next ('iter->chunk_num_' + 1) or previous
|
|
// ('iter->chunk_num_' - 1) chunk. These functions do not loop.
|
|
// Returns true on success, false otherwise.
|
|
WEBP_EXTERN(int) WebPDemuxNextChunk(WebPChunkIterator* iter);
|
|
WEBP_EXTERN(int) WebPDemuxPrevChunk(WebPChunkIterator* iter);
|
|
|
|
// Releases any memory associated with 'iter'.
|
|
// Must be called before destroying the associated WebPDemuxer with
|
|
// WebPDemuxDelete().
|
|
WEBP_EXTERN(void) WebPDemuxReleaseChunkIterator(WebPChunkIterator* iter);
|
|
|
|
//------------------------------------------------------------------------------
|
|
|
|
#if defined(__cplusplus) || defined(c_plusplus)
|
|
} // extern "C"
|
|
#endif
|
|
|
|
#endif /* WEBP_WEBP_MUX_H_ */
|