libwebp/src/webp/mux.h

// Copyright 2011 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/
// -----------------------------------------------------------------------------
//
//  RIFF container manipulation for WEBP images.
//
// Authors: Urvang (urvang@google.com)
//          Vikas (vikasa@google.com)

// This API allows manipulation of WebP container images containing features
// like Color profile, XMP metadata, Animation and Tiling.
//
// Code Example#1: Creating a MUX with image data, color profile and XMP
// metadata.
//
//   int copy_data = 0;
//   WebPMux* mux = WebPMuxNew();
//   // ... (Prepare image data).
//   WebPMuxSetImage(mux, &image, copy_data);
//   // ... (Prepare ICCP color profile data).
//   WebPMuxSetChunk(mux, "ICCP", &icc_profile, copy_data);
//   // ... (Prepare XMP metadata).
//   WebPMuxSetChunk(mux, "META", &xmp, copy_data);
//   // Get data from mux in WebP RIFF format.
//   WebPMuxAssemble(mux, &output_data);
//   WebPMuxDelete(mux);
//   // ... (Consume output_data; e.g. write output_data.bytes to file).
//   WebPDataClear(&output_data);
//
// Code Example#2: Get image and color profile data from a WebP file.
//
//   int copy_data = 0;
//   // ... (Read data from file).
//   WebPMux* mux = WebPMuxCreate(&data, copy_data);
//   WebPMuxGetFrame(mux, 1, &image);
//   // ... (Consume image; e.g. call WebPDecode() to decode the data).
//   WebPMuxGetChunk(mux, "ICCP", &icc_profile);
//   // ... (Consume icc_data).
//   WebPMuxDelete(mux);
//   free(data);

#ifndef WEBP_WEBP_MUX_H_
#define WEBP_WEBP_MUX_H_

#include "./types.h"

#if defined(__cplusplus) || defined(c_plusplus)
extern "C" {
#endif

#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;
#endif
typedef struct WebPMuxFrameInfo WebPMuxFrameInfo;

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,
  WEBP_MUX_NOT_FOUND          =  0,
  WEBP_MUX_INVALID_ARGUMENT   = -1,
  WEBP_MUX_BAD_DATA           = -2,
  WEBP_MUX_MEMORY_ERROR       = -3,
  WEBP_MUX_NOT_ENOUGH_DATA    = -4
};

// Flag values for different features used in VP8X chunk.
enum WebPFeatureFlags {
  TILE_FLAG       = 0x00000001,
  ANIMATION_FLAG  = 0x00000002,
  ICCP_FLAG       = 0x00000004,
  META_FLAG       = 0x00000008,
  ALPHA_FLAG      = 0x00000010
};

// IDs for different types of chunks.
enum WebPChunkId {
  WEBP_CHUNK_VP8X,     // VP8X
  WEBP_CHUNK_ICCP,     // ICCP
  WEBP_CHUNK_LOOP,     // LOOP
  WEBP_CHUNK_ANMF,     // ANMF
  WEBP_CHUNK_FRGM,     // FRGM
  WEBP_CHUNK_ALPHA,    // ALPH
  WEBP_CHUNK_IMAGE,    // VP8/VP8L
  WEBP_CHUNK_META,     // META
  WEBP_CHUNK_UNKNOWN,  // Other chunks.
  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

// Internal, version-checked, entry point
WEBP_EXTERN(WebPMux*) WebPNewInternal(int);

// Creates an empty mux object.
// Returns:
//   A pointer to the newly created empty mux object.
static WEBP_INLINE WebPMux* WebPMuxNew(void) {
  return WebPNewInternal(WEBP_MUX_ABI_VERSION);
}

// Deletes the mux object.
// Parameters:
//   mux - (in/out) object to be deleted
WEBP_EXTERN(void) WebPMuxDelete(WebPMux* mux);

//------------------------------------------------------------------------------
// Mux creation.

// Internal, version-checked, entry point
WEBP_EXTERN(WebPMux*) WebPMuxCreateInternal(const WebPData*, int, int);

// Creates a mux object from raw data given in WebP RIFF format.
// Parameters:
//   bitstream - (in) the bitstream data in WebP RIFF format
//   copy_data - (in) value 1 indicates given data WILL be copied to the mux
//               and value 0 indicates data will NOT be copied.
// Returns:
//   A pointer to the mux object created from given data - on success.
//   NULL - In case of invalid data or memory error.
static WEBP_INLINE WebPMux* WebPMuxCreate(const WebPData* bitstream,
                                          int copy_data) {
  return WebPMuxCreateInternal(bitstream, copy_data, WEBP_MUX_ABI_VERSION);
}

//------------------------------------------------------------------------------
// Non-image chunks.

// Note: Only non-image related chunks should be managed through chunk APIs.
// (Image related chunks are: "ANMF", "FRGM", "VP8 ", "VP8L" and "ALPH").
// To add, get and delete images, use APIs WebPMuxSetImage(),
// WebPMuxPushFrame(), WebPMuxGetFrame() and WebPMuxDeleteFrame().

// Adds a chunk with id 'fourcc' and data 'chunk_data' in the mux object.
// Any existing chunk(s) with the same id will be removed.
// Parameters:
//   mux - (in/out) object to which the chunk is to be added
//   fourcc - (in) a character array containing the fourcc of the given chunk;
//                 e.g., "ICCP", "META" etc.
//   chunk_data - (in) the chunk data to be added
//   copy_data - (in) value 1 indicates given data WILL be copied to the mux
//               and value 0 indicates data will NOT be copied.
// Returns:
//   WEBP_MUX_INVALID_ARGUMENT - if mux, fourcc or chunk_data is NULL
//                               or if fourcc corresponds to an image chunk.
//   WEBP_MUX_MEMORY_ERROR - on memory allocation error.
//   WEBP_MUX_OK - on success.
WEBP_EXTERN(WebPMuxError) WebPMuxSetChunk(
    WebPMux* mux, const char fourcc[4], const WebPData* chunk_data,
    int copy_data);

// Gets a reference to the data of the chunk with id 'fourcc' in the mux object.
// The caller should NOT free the returned data.
// Parameters:
//   mux - (in) object from which the chunk data is to be fetched
//   fourcc - (in) a character array containing the fourcc of the chunk;
//                 e.g., "ICCP", "META" etc.
//   chunk_data - (out) returned chunk data
// Returns:
//   WEBP_MUX_INVALID_ARGUMENT - if either mux, fourcc or chunk_data is NULL
//                               or if fourcc corresponds to an image chunk.
//   WEBP_MUX_NOT_FOUND - If mux does not contain a chunk with the given id.
//   WEBP_MUX_OK - on success.
WEBP_EXTERN(WebPMuxError) WebPMuxGetChunk(
    const WebPMux* mux, const char fourcc[4], WebPData* chunk_data);

// Deletes the chunk with the given 'fourcc' from the mux object.
// Parameters:
//   mux - (in/out) object from which the chunk is to be deleted
//   fourcc - (in) a character array containing the fourcc of the chunk;
//                 e.g., "ICCP", "META" etc.
// Returns:
//   WEBP_MUX_INVALID_ARGUMENT - if mux or fourcc is NULL
//                               or if fourcc corresponds to an image chunk.
//   WEBP_MUX_NOT_FOUND - If mux does not contain a chunk with the given fourcc.
//   WEBP_MUX_OK - on success.
WEBP_EXTERN(WebPMuxError) WebPMuxDeleteChunk(
    WebPMux* mux, const char fourcc[4]);

//------------------------------------------------------------------------------
// Images.

// Encapsulates data about a single frame/tile.
struct WebPMuxFrameInfo {
  WebPData    bitstream;  // image data: can either be a raw VP8/VP8L bitstream
                          // or a single-image WebP file.
  int         x_offset;   // x-offset of the frame.
  int         y_offset;   // y-offset of the frame.
  int         duration;   // duration of the frame (in milliseconds).

  WebPChunkId id;         // frame type: should be one of WEBP_CHUNK_ANMF,
                          // WEBP_CHUNK_FRGM or WEBP_CHUNK_IMAGE
  uint32_t pad[3];        // padding for later use
};

// Sets the (non-animated and non-tiled) image in the mux object.
// Note: Any existing images (including frames/tiles) will be removed.
// Parameters:
//   mux - (in/out) object in which the image is to be set
//   bitstream - (in) can either be a raw VP8/VP8L bitstream or a single-image
//               WebP file (non-animated and non-tiled)
//   copy_data - (in) value 1 indicates given data WILL be copied to the mux
//               and value 0 indicates data will NOT be copied.
// Returns:
//   WEBP_MUX_INVALID_ARGUMENT - if mux is NULL or bitstream is NULL.
//   WEBP_MUX_MEMORY_ERROR - on memory allocation error.
//   WEBP_MUX_OK - on success.
WEBP_EXTERN(WebPMuxError) WebPMuxSetImage(
    WebPMux* mux, const WebPData* bitstream, int copy_data);

// Adds a frame at the end of the mux object.
// Notes: (1) frame.id should be one of WEBP_CHUNK_ANMF or WEBP_CHUNK_FRGM
//        (2) For setting a non-animated non-tiled image, use WebPMuxSetImage()
//            instead.
//        (3) Type of frame being pushed must be same as the frames in mux.
//        (4) As WebP only supports even offsets, any odd offset will be snapped
//            to an even location using: offset &= ~1
// Parameters:
//   mux - (in/out) object to which the frame is to be added
//   frame - (in) frame data.
//   copy_data - (in) value 1 indicates given data WILL be copied to the mux
//               and value 0 indicates data will NOT be copied.
// Returns:
//   WEBP_MUX_INVALID_ARGUMENT - if mux or frame is NULL
//                               or if content of 'frame' is invalid.
//   WEBP_MUX_MEMORY_ERROR - on memory allocation error.
//   WEBP_MUX_OK - on success.
WEBP_EXTERN(WebPMuxError) WebPMuxPushFrame(
    WebPMux* mux, const WebPMuxFrameInfo* frame, int copy_data);

// Gets the nth frame from the mux object.
// The content of 'frame->bitstream' is allocated using malloc(), and NOT
// owned by the 'mux' object. It MUST be deallocated by the caller by calling
// WebPDataClear().
// nth=0 has a special meaning - last position.
// Parameters:
//   mux - (in) object from which the info is to be fetched
//   nth - (in) index of the frame in the mux object
//   frame - (out) data of the returned frame
// Returns:
//   WEBP_MUX_INVALID_ARGUMENT - if mux or frame is NULL.
//   WEBP_MUX_NOT_FOUND - if there are less than nth frames in the mux object.
//   WEBP_MUX_BAD_DATA - if nth frame chunk in mux is invalid.
//   WEBP_MUX_OK - on success.
WEBP_EXTERN(WebPMuxError) WebPMuxGetFrame(
    const WebPMux* mux, uint32_t nth, WebPMuxFrameInfo* frame);

// Deletes a frame from the mux object.
// nth=0 has a special meaning - last position.
// Parameters:
//   mux - (in/out) object from which a frame is to be deleted
//   nth - (in) The position from which the frame is to be deleted
// Returns:
//   WEBP_MUX_INVALID_ARGUMENT - if mux is NULL.
//   WEBP_MUX_NOT_FOUND - If there are less than nth frames in the mux object
//                        before deletion.
//   WEBP_MUX_OK - on success.
WEBP_EXTERN(WebPMuxError) WebPMuxDeleteFrame(WebPMux* mux, uint32_t nth);

//------------------------------------------------------------------------------
// Animation.

// Sets the animation loop count in the mux object. Any existing loop count
// value(s) will be removed.
// Parameters:
//   mux - (in/out) object in which loop chunk is to be set/added
//   loop_count - (in) animation loop count value.
//                Note that loop_count of zero denotes infinite loop.
// Returns:
//   WEBP_MUX_INVALID_ARGUMENT - if mux is NULL
//   WEBP_MUX_MEMORY_ERROR - on memory allocation error.
//   WEBP_MUX_OK - on success.
WEBP_EXTERN(WebPMuxError) WebPMuxSetLoopCount(WebPMux* mux, int loop_count);

// Gets the animation loop count from the mux object.
// Parameters:
//   mux - (in) object from which the loop count is to be fetched
//   loop_count - (out) the loop_count value present in the LOOP chunk
// Returns:
//   WEBP_MUX_INVALID_ARGUMENT - if either of mux or loop_count is NULL
//   WEBP_MUX_NOT_FOUND - if loop chunk is not present in mux object.
//   WEBP_MUX_OK - on success.
WEBP_EXTERN(WebPMuxError) WebPMuxGetLoopCount(const WebPMux* mux,
                                              int* loop_count);

//------------------------------------------------------------------------------
// Misc Utilities.

// Gets the feature flags from the mux object.
// Parameters:
//   mux - (in) object from which the features are to be fetched
//   flags - (out) the flags specifying which features are present in the
//           mux object. This will be an OR of various flag values.
//           Enum 'WebPFeatureFlags' can be used to test individual flag values.
// Returns:
//   WEBP_MUX_INVALID_ARGUMENT - if mux or flags is NULL
//   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)

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
};

// 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 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_;            // for internal use only.
};

// 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.

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", "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_ */