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Separate out mux and demux code and libraries:

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- Separate out mux.h and demux.h
- muxtypes.h: new header for data types common to mux/demux
- Move some misc read/write utilities to utils/utils.h
- Remove some duplicate methods.
- Separate out mux/demux libraries

Change-Id: If9b9569b10d55d922ad9317ef51710544315d6de
This commit is contained in:
Urvang Joshi
2012-11-19 11:21:37 -08:00
parent 90e5e3190c
commit 23782f95b4
20 changed files with 398 additions and 344 deletions
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171
src/webp/demux.h Normal file
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@ -0,0 +1,171 @@
// 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/
// -----------------------------------------------------------------------------
//
// Demux API.
// Enables extraction of image and extended format data from WebP files.
// TODO(urvang): Add an example code snippet (similar to mux.h).
#ifndef WEBP_WEBP_DEMUX_H_
#define WEBP_WEBP_DEMUX_H_
#include "./format_constants.h"
#include "./mux_types.h"
#if defined(__cplusplus) || defined(c_plusplus)
extern "C" {
#endif
#define WEBP_DEMUX_ABI_VERSION 0x0100 // MAJOR(8b) + MINOR(8b)
typedef struct WebPDemuxer WebPDemuxer;
#if !(defined(__cplusplus) || defined(c_plusplus))
typedef enum WebPDemuxState WebPDemuxState;
typedef enum WebPFormatFeature WebPFormatFeature;
#endif
typedef struct WebPIterator WebPIterator;
typedef struct WebPChunkIterator WebPChunkIterator;
//------------------------------------------------------------------------------
// Life of a Demux object
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.
};
// 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.
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
};
// 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;
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 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_ */

20
src/webp/format_constants.h
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@ -70,14 +70,18 @@ typedef enum {
#define FRGM_CHUNK_SIZE 6 // Size of a FRGM chunk.
#define VP8X_CHUNK_SIZE 10 // Size of a VP8X chunk.
// VP8X Feature Flags. These should be the same as the corresponding values in
// the 'WebPFeatureFlags' enum defined in mux.h.
#define FRAGMENTS_FLAG_BIT 0x01
#define ANIMATION_FLAG_BIT 0x02
#define XMP_FLAG_BIT 0x04
#define EXIF_FLAG_BIT 0x08
#define ALPHA_FLAG_BIT 0x10
#define ICC_FLAG_BIT 0x20
// VP8X Feature Flags.
#if !(defined(__cplusplus) || defined(c_plusplus))
typedef enum WebPFeatureFlags WebPFeatureFlags;
#endif
enum WebPFeatureFlags {
FRAGMENTS_FLAG = 0x00000001,
ANIMATION_FLAG = 0x00000002,
XMP_FLAG = 0x00000004,
EXIF_FLAG = 0x00000008,
ALPHA_FLAG = 0x00000010,
ICCP_FLAG = 0x00000020
};
#define MAX_CANVAS_SIZE (1 << 24) // 24-bit max for VP8X width/height.
#define MAX_IMAGE_AREA (1ULL << 32) // 32-bit max for width x height.

190
src/webp/mux.h
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@ -45,7 +45,8 @@
#ifndef WEBP_WEBP_MUX_H_
#define WEBP_WEBP_MUX_H_
#include "./types.h"
#include "./format_constants.h"
#include "./mux_types.h"
#if defined(__cplusplus) || defined(c_plusplus)
extern "C" {
@ -54,24 +55,13 @@ extern "C" {
#define WEBP_MUX_ABI_VERSION 0x0100 // MAJOR(8b) + MINOR(8b)
typedef struct WebPMux WebPMux; // main opaque object.
typedef struct WebPData WebPData;
#if !(defined(__cplusplus) || defined(c_plusplus))
typedef enum WebPMuxError WebPMuxError;
typedef enum WebPFeatureFlags WebPFeatureFlags;
typedef enum WebPChunkId WebPChunkId;
typedef enum WebPMuxAnimDispose WebPMuxAnimDispose;
#endif
typedef struct WebPMuxFrameInfo WebPMuxFrameInfo;
typedef struct WebPMuxAnimParams WebPMuxAnimParams;
typedef struct WebPDemuxer WebPDemuxer;
#if !(defined(__cplusplus) || defined(c_plusplus))
typedef enum WebPDemuxState WebPDemuxState;
typedef enum WebPFormatFeature WebPFormatFeature;
#endif
typedef struct WebPIterator WebPIterator;
typedef struct WebPChunkIterator WebPChunkIterator;
// Error codes
enum WebPMuxError {
WEBP_MUX_OK = 1,
@ -82,16 +72,6 @@ enum WebPMuxError {
WEBP_MUX_NOT_ENOUGH_DATA = -4
};
// Flag values for different features used in VP8X chunk.
enum WebPFeatureFlags {
FRAGMENTS_FLAG = 0x00000001,
ANIMATION_FLAG = 0x00000002,
XMP_FLAG = 0x00000004,
EXIF_FLAG = 0x00000008,
ALPHA_FLAG = 0x00000010,
ICCP_FLAG = 0x00000020
};
// IDs for different types of chunks.
enum WebPChunkId {
WEBP_CHUNK_VP8X, // VP8X
@ -107,27 +87,6 @@ enum WebPChunkId {
WEBP_CHUNK_NIL
};
// Data type used to describe 'raw' data, e.g., chunk data
// (ICC profile, metadata) and WebP compressed image data.
struct WebPData {
const uint8_t* bytes;
size_t size;
};
//------------------------------------------------------------------------------
// Manipulation of a WebPData object.
// Initializes the contents of the 'webp_data' object with default values.
WEBP_EXTERN(void) WebPDataInit(WebPData* webp_data);
// Clears the contents of the 'webp_data' object by calling free(). Does not
// deallocate the object itself.
WEBP_EXTERN(void) WebPDataClear(WebPData* webp_data);
// Allocates necessary storage for 'dst' and copies the contents of 'src'.
// Returns true on success.
WEBP_EXTERN(int) WebPDataCopy(const WebPData* src, WebPData* dst);
//------------------------------------------------------------------------------
// Life of a Mux object
@ -222,13 +181,6 @@ WEBP_EXTERN(WebPMuxError) WebPMuxDeleteChunk(
//------------------------------------------------------------------------------
// Images.
// Dispose method (animation only). Indicates how the area used by the current
// frame is to be treated before rendering the next frame on the canvas.
enum WebPMuxAnimDispose {
WEBP_MUX_DISPOSE_NONE, // Do not dispose.
WEBP_MUX_DISPOSE_BACKGROUND // Dispose to background color.
};
// Encapsulates data about a single frame/fragment.
struct WebPMuxFrameInfo {
WebPData bitstream; // image data: can either be a raw VP8/VP8L bitstream
@ -389,144 +341,6 @@ WEBP_EXTERN(WebPMuxError) WebPMuxNumChunks(const WebPMux* mux,
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)
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.
};
//------------------------------------------------------------------------------
// 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.
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
};
// 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;
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 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)

78
src/webp/mux_types.h Normal file
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@ -0,0 +1,78 @@
// 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/
// -----------------------------------------------------------------------------
//
// Internal header for some common data-types used by mux and demux libraries.
//
// Author: Urvang (urvang@google.com)
#ifndef WEBP_WEBP_MUX_TYPES_H_
#define WEBP_WEBP_MUX_TYPES_H_
#include <stdlib.h> // free()
#include <string.h> // memset()
#include "./types.h"
#if defined(__cplusplus) || defined(c_plusplus)
extern "C" {
#endif
// Create fourcc of the chunk from the chunk tag characters.
#define MKFOURCC(a, b, c, d) ((uint32_t)(a) | (b) << 8 | (c) << 16 | (d) << 24)
// Dispose method (animation only). Indicates how the area used by the current
// frame is to be treated before rendering the next frame on the canvas.
#if !(defined(__cplusplus) || defined(c_plusplus))
typedef enum WebPMuxAnimDispose WebPMuxAnimDispose;
#endif
enum WebPMuxAnimDispose {
WEBP_MUX_DISPOSE_NONE, // Do not dispose.
WEBP_MUX_DISPOSE_BACKGROUND // Dispose to background color.
};
// Data type used to describe 'raw' data, e.g., chunk data
// (ICC profile, metadata) and WebP compressed image data.
typedef struct WebPData WebPData;
struct WebPData {
const uint8_t* bytes;
size_t size;
};
// Initializes the contents of the 'webp_data' object with default values.
static WEBP_INLINE void WebPDataInit(WebPData* webp_data) {
if (webp_data != NULL) {
memset(webp_data, 0, sizeof(*webp_data));
}
}
// Clears the contents of the 'webp_data' object by calling free(). Does not
// deallocate the object itself.
static WEBP_INLINE void WebPDataClear(WebPData* webp_data) {
if (webp_data != NULL) {
free((void*)webp_data->bytes);
WebPDataInit(webp_data);
}
}
// Allocates necessary storage for 'dst' and copies the contents of 'src'.
// Returns true on success.
static WEBP_INLINE int WebPDataCopy(const WebPData* src, WebPData* dst) {
if (src == NULL || dst == NULL) return 0;
WebPDataInit(dst);
if (src->bytes != NULL && src->size != 0) {
dst->bytes = (uint8_t*)malloc(src->size);
if (dst->bytes == NULL) return 0;
memcpy((void*)dst->bytes, src->bytes, src->size);
dst->size = src->size;
}
return 1;
}
#if defined(__cplusplus) || defined(c_plusplus)
} // extern "C"
#endif
#endif /* WEBP_WEBP_MUX_TYPES_H_ */