mirror of
https://github.com/opencv/opencv.git
synced 2024-12-12 23:49:36 +08:00
215 lines
9.0 KiB
C
215 lines
9.0 KiB
C
// Copyright 2012 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.
|
|
// -----------------------------------------------------------------------------
|
|
//
|
|
// Demux API.
|
|
// Enables extraction of image and extended format data from WebP files.
|
|
|
|
// Code Example: Demuxing WebP data to extract all the frames, ICC profile
|
|
// and EXIF/XMP metadata.
|
|
//
|
|
// WebPDemuxer* demux = WebPDemux(&webp_data);
|
|
//
|
|
// uint32_t width = WebPDemuxGetI(demux, WEBP_FF_CANVAS_WIDTH);
|
|
// uint32_t height = WebPDemuxGetI(demux, WEBP_FF_CANVAS_HEIGHT);
|
|
// // ... (Get information about the features present in the WebP file).
|
|
// uint32_t flags = WebPDemuxGetI(demux, WEBP_FF_FORMAT_FLAGS);
|
|
//
|
|
// // ... (Iterate over all frames).
|
|
// WebPIterator iter;
|
|
// if (WebPDemuxGetFrame(demux, 1, &iter)) {
|
|
// do {
|
|
// // ... (Consume 'iter'; e.g. Decode 'iter.fragment' with WebPDecode(),
|
|
// // ... and get other frame properties like width, height, offsets etc.
|
|
// // ... see 'struct WebPIterator' below for more info).
|
|
// } while (WebPDemuxNextFrame(&iter));
|
|
// WebPDemuxReleaseIterator(&iter);
|
|
// }
|
|
//
|
|
// // ... (Extract metadata).
|
|
// WebPChunkIterator chunk_iter;
|
|
// if (flags & ICCP_FLAG) WebPDemuxGetChunk(demux, "ICCP", 1, &chunk_iter);
|
|
// // ... (Consume the ICC profile in 'chunk_iter.chunk').
|
|
// WebPDemuxReleaseChunkIterator(&chunk_iter);
|
|
// if (flags & EXIF_FLAG) WebPDemuxGetChunk(demux, "EXIF", 1, &chunk_iter);
|
|
// // ... (Consume the EXIF metadata in 'chunk_iter.chunk').
|
|
// WebPDemuxReleaseChunkIterator(&chunk_iter);
|
|
// if (flags & XMP_FLAG) WebPDemuxGetChunk(demux, "XMP ", 1, &chunk_iter);
|
|
// // ... (Consume the XMP metadata in 'chunk_iter.chunk').
|
|
// WebPDemuxReleaseChunkIterator(&chunk_iter);
|
|
// WebPDemuxDelete(demux);
|
|
|
|
#ifndef WEBP_WEBP_DEMUX_H_
|
|
#define WEBP_WEBP_DEMUX_H_
|
|
|
|
#include "./mux_types.h"
|
|
|
|
#if defined(__cplusplus) || defined(c_plusplus)
|
|
extern "C" {
|
|
#endif
|
|
|
|
#define WEBP_DEMUX_ABI_VERSION 0x0100 // MAJOR(8b) + MINOR(8b)
|
|
|
|
// Note: forward declaring enumerations is not allowed in (strict) C and C++,
|
|
// the types are left here for reference.
|
|
// typedef enum WebPDemuxState WebPDemuxState;
|
|
// typedef enum WebPFormatFeature WebPFormatFeature;
|
|
typedef struct WebPDemuxer WebPDemuxer;
|
|
typedef struct WebPIterator WebPIterator;
|
|
typedef struct WebPChunkIterator WebPChunkIterator;
|
|
|
|
//------------------------------------------------------------------------------
|
|
|
|
// Returns the version number of the demux library, packed in hexadecimal using
|
|
// 8bits for each of major/minor/revision. E.g: v2.5.7 is 0x020507.
|
|
WEBP_EXTERN(int) WebPGetDemuxVersion(void);
|
|
|
|
//------------------------------------------------------------------------------
|
|
// Life of a Demux object
|
|
|
|
typedef enum WebPDemuxState {
|
|
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;
|
|
|
|
// Internal, version-checked, entry point
|
|
WEBP_EXTERN(WebPDemuxer*) WebPDemuxInternal(
|
|
const WebPData*, int, WebPDemuxState*, int);
|
|
|
|
// Parses the full WebP file given by 'data'.
|
|
// 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 possibly incomplete 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 WebPFormatFeature {
|
|
WEBP_FF_FORMAT_FLAGS, // Extended format flags present in the 'VP8X' chunk.
|
|
WEBP_FF_CANVAS_WIDTH,
|
|
WEBP_FF_CANVAS_HEIGHT,
|
|
WEBP_FF_LOOP_COUNT,
|
|
WEBP_FF_BACKGROUND_COLOR,
|
|
WEBP_FF_FRAME_COUNT // Number of frames present in the demux object.
|
|
// In case of a partial demux, this is the number of
|
|
// frames seen so far, with the last frame possibly
|
|
// being partial.
|
|
} 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.
|
|
|
|
struct WebPIterator {
|
|
int frame_num;
|
|
int num_frames; // equivalent to WEBP_FF_FRAME_COUNT.
|
|
int fragment_num;
|
|
int num_fragments;
|
|
int x_offset, y_offset; // offset relative to the canvas.
|
|
int width, height; // dimensions of this frame or fragment.
|
|
int duration; // display duration in milliseconds.
|
|
WebPMuxAnimDispose dispose_method; // dispose method for the frame.
|
|
int complete; // true if 'fragment' contains a full frame. partial images
|
|
// may still be decoded with the WebP incremental decoder.
|
|
WebPData fragment; // The frame or fragment given by 'frame_num' and
|
|
// 'fragment_num'.
|
|
|
|
uint32_t pad[4]; // padding for later use.
|
|
void* private_; // for internal use only.
|
|
};
|
|
|
|
// Retrieves frame 'frame_number' from 'dmux'.
|
|
// 'iter->fragment' points to the first fragment on return from this function.
|
|
// Individual fragments may be extracted using WebPDemuxSetFragment().
|
|
// 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->fragment' 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->fragment' to reflect fragment number 'fragment_num'.
|
|
// Returns true if fragment 'fragment_num' is present, false otherwise.
|
|
WEBP_EXTERN(int) WebPDemuxSelectFragment(WebPIterator* iter, int fragment_num);
|
|
|
|
// Releases any memory associated with 'iter'.
|
|
// Must be called before any subsequent calls to WebPDemuxGetChunk() on the same
|
|
// iter. Also, must be called before destroying the associated WebPDemuxer with
|
|
// WebPDemuxDelete().
|
|
WEBP_EXTERN(void) WebPDemuxReleaseIterator(WebPIterator* iter);
|
|
|
|
//------------------------------------------------------------------------------
|
|
// Chunk iteration.
|
|
|
|
struct WebPChunkIterator {
|
|
// 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_;
|
|
};
|
|
|
|
// 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", "XMP ", "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_DEMUX_H_ */
|