1// Copyright 2011 Google Inc. All Rights Reserved. 
2// 
3// Use of this source code is governed by a BSD-style license 
4// that can be found in the COPYING file in the root of the source 
5// tree. An additional intellectual property rights grant can be found 
6// in the file PATENTS. All contributing project authors may 
7// be found in the AUTHORS file in the root of the source tree. 
8// ----------------------------------------------------------------------------- 
9// 
10// RIFF container manipulation and encoding for WebP images. 
11// 
12// Authors: Urvang (urvang@google.com) 
13// Vikas (vikasa@google.com) 
14 
15#ifndef WEBP_WEBP_MUX_H_ 
16#define WEBP_WEBP_MUX_H_ 
17 
18#include "./mux_types.h" 
19 
20#ifdef __cplusplus 
21extern "C" { 
22#endif 
23 
24#define WEBP_MUX_ABI_VERSION 0x0108 // MAJOR(8b) + MINOR(8b) 
25 
26//------------------------------------------------------------------------------ 
27// Mux API 
28// 
29// This API allows manipulation of WebP container images containing features 
30// like color profile, metadata, animation. 
31// 
32// Code Example#1: Create a WebPMux object with image data, color profile and 
33// XMP metadata. 
34/* 
35 int copy_data = 0; 
36 WebPMux* mux = WebPMuxNew(); 
37 // ... (Prepare image data). 
38 WebPMuxSetImage(mux, &image, copy_data); 
39 // ... (Prepare ICCP color profile data). 
40 WebPMuxSetChunk(mux, "ICCP", &icc_profile, copy_data); 
41 // ... (Prepare XMP metadata). 
42 WebPMuxSetChunk(mux, "XMP ", &xmp, copy_data); 
43 // Get data from mux in WebP RIFF format. 
44 WebPMuxAssemble(mux, &output_data); 
45 WebPMuxDelete(mux); 
46 // ... (Consume output_data; e.g. write output_data.bytes to file). 
47 WebPDataClear(&output_data); 
48*/ 
49 
50// Code Example#2: Get image and color profile data from a WebP file. 
51/* 
52 int copy_data = 0; 
53 // ... (Read data from file). 
54 WebPMux* mux = WebPMuxCreate(&data, copy_data); 
55 WebPMuxGetFrame(mux, 1, &image); 
56 // ... (Consume image; e.g. call WebPDecode() to decode the data). 
57 WebPMuxGetChunk(mux, "ICCP", &icc_profile); 
58 // ... (Consume icc_data). 
59 WebPMuxDelete(mux); 
60 WebPFree(data); 
61*/ 
62 
63// Note: forward declaring enumerations is not allowed in (strict) C and C++, 
64// the types are left here for reference. 
65// typedef enum WebPMuxError WebPMuxError; 
66// typedef enum WebPChunkId WebPChunkId; 
67typedef struct WebPMux WebPMux; // main opaque object. 
68typedef struct WebPMuxFrameInfo WebPMuxFrameInfo; 
69typedef struct WebPMuxAnimParams WebPMuxAnimParams; 
70typedef struct WebPAnimEncoderOptions WebPAnimEncoderOptions; 
71 
72// Error codes 
73typedef enum WebPMuxError { 
74 WEBP_MUX_OK = 1, 
75 WEBP_MUX_NOT_FOUND = 0, 
76 WEBP_MUX_INVALID_ARGUMENT = -1, 
77 WEBP_MUX_BAD_DATA = -2, 
78 WEBP_MUX_MEMORY_ERROR = -3, 
79 WEBP_MUX_NOT_ENOUGH_DATA = -4 
80} WebPMuxError; 
81 
82// IDs for different types of chunks. 
83typedef enum WebPChunkId { 
84 WEBP_CHUNK_VP8X, // VP8X 
85 WEBP_CHUNK_ICCP, // ICCP 
86 WEBP_CHUNK_ANIM, // ANIM 
87 WEBP_CHUNK_ANMF, // ANMF 
88 WEBP_CHUNK_DEPRECATED, // (deprecated from FRGM) 
89 WEBP_CHUNK_ALPHA, // ALPH 
90 WEBP_CHUNK_IMAGE, // VP8/VP8L 
91 WEBP_CHUNK_EXIF, // EXIF 
92 WEBP_CHUNK_XMP, // XMP 
93 WEBP_CHUNK_UNKNOWN, // Other chunks. 
94 WEBP_CHUNK_NIL 
95} WebPChunkId; 
96 
97//------------------------------------------------------------------------------ 
98 
99// Returns the version number of the mux library, packed in hexadecimal using 
100// 8bits for each of major/minor/revision. E.g: v2.5.7 is 0x020507. 
101WEBP_EXTERN int WebPGetMuxVersion(void); 
102 
103//------------------------------------------------------------------------------ 
104// Life of a Mux object 
105 
106// Internal, version-checked, entry point 
107WEBP_EXTERN WebPMux* WebPNewInternal(int); 
108 
109// Creates an empty mux object. 
110// Returns: 
111// A pointer to the newly created empty mux object. 
112// Or NULL in case of memory error. 
113static WEBP_INLINE WebPMux* WebPMuxNew(void) { 
114 return WebPNewInternal(WEBP_MUX_ABI_VERSION); 
115} 
116 
117// Deletes the mux object. 
118// Parameters: 
119// mux - (in/out) object to be deleted 
120WEBP_EXTERN void WebPMuxDelete(WebPMux* mux); 
121 
122//------------------------------------------------------------------------------ 
123// Mux creation. 
124 
125// Internal, version-checked, entry point 
126WEBP_EXTERN WebPMux* WebPMuxCreateInternal(const WebPData*, int, int); 
127 
128// Creates a mux object from raw data given in WebP RIFF format. 
129// Parameters: 
130// bitstream - (in) the bitstream data in WebP RIFF format 
131// copy_data - (in) value 1 indicates given data WILL be copied to the mux 
132// object and value 0 indicates data will NOT be copied. 
133// Returns: 
134// A pointer to the mux object created from given data - on success. 
135// NULL - In case of invalid data or memory error. 
136static WEBP_INLINE WebPMux* WebPMuxCreate(const WebPData* bitstream, 
137 int copy_data) { 
138 return WebPMuxCreateInternal(bitstream, copy_data, WEBP_MUX_ABI_VERSION); 
139} 
140 
141//------------------------------------------------------------------------------ 
142// Non-image chunks. 
143 
144// Note: Only non-image related chunks should be managed through chunk APIs. 
145// (Image related chunks are: "ANMF", "VP8 ", "VP8L" and "ALPH"). 
146// To add, get and delete images, use WebPMuxSetImage(), WebPMuxPushFrame(), 
147// WebPMuxGetFrame() and WebPMuxDeleteFrame(). 
148 
149// Adds a chunk with id 'fourcc' and data 'chunk_data' in the mux object. 
150// Any existing chunk(s) with the same id will be removed. 
151// Parameters: 
152// mux - (in/out) object to which the chunk is to be added 
153// fourcc - (in) a character array containing the fourcc of the given chunk; 
154// e.g., "ICCP", "XMP ", "EXIF" etc. 
155// chunk_data - (in) the chunk data to be added 
156// copy_data - (in) value 1 indicates given data WILL be copied to the mux 
157// object and value 0 indicates data will NOT be copied. 
158// Returns: 
159// WEBP_MUX_INVALID_ARGUMENT - if mux, fourcc or chunk_data is NULL 
160// or if fourcc corresponds to an image chunk. 
161// WEBP_MUX_MEMORY_ERROR - on memory allocation error. 
162// WEBP_MUX_OK - on success. 
163WEBP_EXTERN WebPMuxError WebPMuxSetChunk( 
164 WebPMux* mux, const char fourcc[4], const WebPData* chunk_data, 
165 int copy_data); 
166 
167// Gets a reference to the data of the chunk with id 'fourcc' in the mux object. 
168// The caller should NOT free the returned data. 
169// Parameters: 
170// mux - (in) object from which the chunk data is to be fetched 
171// fourcc - (in) a character array containing the fourcc of the chunk; 
172// e.g., "ICCP", "XMP ", "EXIF" etc. 
173// chunk_data - (out) returned chunk data 
174// Returns: 
175// WEBP_MUX_INVALID_ARGUMENT - if mux, fourcc or chunk_data is NULL 
176// or if fourcc corresponds to an image chunk. 
177// WEBP_MUX_NOT_FOUND - If mux does not contain a chunk with the given id. 
178// WEBP_MUX_OK - on success. 
179WEBP_EXTERN WebPMuxError WebPMuxGetChunk( 
180 const WebPMux* mux, const char fourcc[4], WebPData* chunk_data); 
181 
182// Deletes the chunk with the given 'fourcc' from the mux object. 
183// Parameters: 
184// mux - (in/out) object from which the chunk is to be deleted 
185// fourcc - (in) a character array containing the fourcc of the chunk; 
186// e.g., "ICCP", "XMP ", "EXIF" etc. 
187// Returns: 
188// WEBP_MUX_INVALID_ARGUMENT - if mux or fourcc is NULL 
189// or if fourcc corresponds to an image chunk. 
190// WEBP_MUX_NOT_FOUND - If mux does not contain a chunk with the given fourcc. 
191// WEBP_MUX_OK - on success. 
192WEBP_EXTERN WebPMuxError WebPMuxDeleteChunk( 
193 WebPMux* mux, const char fourcc[4]); 
194 
195//------------------------------------------------------------------------------ 
196// Images. 
197 
198// Encapsulates data about a single frame. 
199struct WebPMuxFrameInfo { 
200 WebPData bitstream; // image data: can be a raw VP8/VP8L bitstream 
201 // or a single-image WebP file. 
202 int x_offset; // x-offset of the frame. 
203 int y_offset; // y-offset of the frame. 
204 int duration; // duration of the frame (in milliseconds). 
205 
206 WebPChunkId id; // frame type: should be one of WEBP_CHUNK_ANMF 
207 // or WEBP_CHUNK_IMAGE 
208 WebPMuxAnimDispose dispose_method; // Disposal method for the frame. 
209 WebPMuxAnimBlend blend_method; // Blend operation for the frame. 
210 uint32_t pad[1]; // padding for later use 
211}; 
212 
213// Sets the (non-animated) image in the mux object. 
214// Note: Any existing images (including frames) will be removed. 
215// Parameters: 
216// mux - (in/out) object in which the image is to be set 
217// bitstream - (in) can be a raw VP8/VP8L bitstream or a single-image 
218// WebP file (non-animated) 
219// copy_data - (in) value 1 indicates given data WILL be copied to the mux 
220// object and value 0 indicates data will NOT be copied. 
221// Returns: 
222// WEBP_MUX_INVALID_ARGUMENT - if mux is NULL or bitstream is NULL. 
223// WEBP_MUX_MEMORY_ERROR - on memory allocation error. 
224// WEBP_MUX_OK - on success. 
225WEBP_EXTERN WebPMuxError WebPMuxSetImage( 
226 WebPMux* mux, const WebPData* bitstream, int copy_data); 
227 
228// Adds a frame at the end of the mux object. 
229// Notes: (1) frame.id should be WEBP_CHUNK_ANMF 
230// (2) For setting a non-animated image, use WebPMuxSetImage() instead. 
231// (3) Type of frame being pushed must be same as the frames in mux. 
232// (4) As WebP only supports even offsets, any odd offset will be snapped 
233// to an even location using: offset &= ~1 
234// Parameters: 
235// mux - (in/out) object to which the frame is to be added 
236// frame - (in) frame data. 
237// copy_data - (in) value 1 indicates given data WILL be copied to the mux 
238// object and value 0 indicates data will NOT be copied. 
239// Returns: 
240// WEBP_MUX_INVALID_ARGUMENT - if mux or frame is NULL 
241// or if content of 'frame' is invalid. 
242// WEBP_MUX_MEMORY_ERROR - on memory allocation error. 
243// WEBP_MUX_OK - on success. 
244WEBP_EXTERN WebPMuxError WebPMuxPushFrame( 
245 WebPMux* mux, const WebPMuxFrameInfo* frame, int copy_data); 
246 
247// Gets the nth frame from the mux object. 
248// The content of 'frame->bitstream' is allocated using WebPMalloc(), and NOT 
249// owned by the 'mux' object. It MUST be deallocated by the caller by calling 
250// WebPDataClear(). 
251// nth=0 has a special meaning - last position. 
252// Parameters: 
253// mux - (in) object from which the info is to be fetched 
254// nth - (in) index of the frame in the mux object 
255// frame - (out) data of the returned frame 
256// Returns: 
257// WEBP_MUX_INVALID_ARGUMENT - if mux or frame is NULL. 
258// WEBP_MUX_NOT_FOUND - if there are less than nth frames in the mux object. 
259// WEBP_MUX_BAD_DATA - if nth frame chunk in mux is invalid. 
260// WEBP_MUX_MEMORY_ERROR - on memory allocation error. 
261// WEBP_MUX_OK - on success. 
262WEBP_EXTERN WebPMuxError WebPMuxGetFrame( 
263 const WebPMux* mux, uint32_t nth, WebPMuxFrameInfo* frame); 
264 
265// Deletes a frame from the mux object. 
266// nth=0 has a special meaning - last position. 
267// Parameters: 
268// mux - (in/out) object from which a frame is to be deleted 
269// nth - (in) The position from which the frame is to be deleted 
270// Returns: 
271// WEBP_MUX_INVALID_ARGUMENT - if mux is NULL. 
272// WEBP_MUX_NOT_FOUND - If there are less than nth frames in the mux object 
273// before deletion. 
274// WEBP_MUX_OK - on success. 
275WEBP_EXTERN WebPMuxError WebPMuxDeleteFrame(WebPMux* mux, uint32_t nth); 
276 
277//------------------------------------------------------------------------------ 
278// Animation. 
279 
280// Animation parameters. 
281struct WebPMuxAnimParams { 
282 uint32_t bgcolor; // Background color of the canvas stored (in MSB order) as: 
283 // Bits 00 to 07: Alpha. 
284 // Bits 08 to 15: Red. 
285 // Bits 16 to 23: Green. 
286 // Bits 24 to 31: Blue. 
287 int loop_count; // Number of times to repeat the animation [0 = infinite]. 
288}; 
289 
290// Sets the animation parameters in the mux object. Any existing ANIM chunks 
291// will be removed. 
292// Parameters: 
293// mux - (in/out) object in which ANIM chunk is to be set/added 
294// params - (in) animation parameters. 
295// Returns: 
296// WEBP_MUX_INVALID_ARGUMENT - if mux or params is NULL. 
297// WEBP_MUX_MEMORY_ERROR - on memory allocation error. 
298// WEBP_MUX_OK - on success. 
299WEBP_EXTERN WebPMuxError WebPMuxSetAnimationParams( 
300 WebPMux* mux, const WebPMuxAnimParams* params); 
301 
302// Gets the animation parameters from the mux object. 
303// Parameters: 
304// mux - (in) object from which the animation parameters to be fetched 
305// params - (out) animation parameters extracted from the ANIM chunk 
306// Returns: 
307// WEBP_MUX_INVALID_ARGUMENT - if mux or params is NULL. 
308// WEBP_MUX_NOT_FOUND - if ANIM chunk is not present in mux object. 
309// WEBP_MUX_OK - on success. 
310WEBP_EXTERN WebPMuxError WebPMuxGetAnimationParams( 
311 const WebPMux* mux, WebPMuxAnimParams* params); 
312 
313//------------------------------------------------------------------------------ 
314// Misc Utilities. 
315 
316// Sets the canvas size for the mux object. The width and height can be 
317// specified explicitly or left as zero (0, 0). 
318// * When width and height are specified explicitly, then this frame bound is 
319// enforced during subsequent calls to WebPMuxAssemble() and an error is 
320// reported if any animated frame does not completely fit within the canvas. 
321// * When unspecified (0, 0), the constructed canvas will get the frame bounds 
322// from the bounding-box over all frames after calling WebPMuxAssemble(). 
323// Parameters: 
324// mux - (in) object to which the canvas size is to be set 
325// width - (in) canvas width 
326// height - (in) canvas height 
327// Returns: 
328// WEBP_MUX_INVALID_ARGUMENT - if mux is NULL; or 
329// width or height are invalid or out of bounds 
330// WEBP_MUX_OK - on success. 
331WEBP_EXTERN WebPMuxError WebPMuxSetCanvasSize(WebPMux* mux, 
332 int width, int height); 
333 
334// Gets the canvas size from the mux object. 
335// Note: This method assumes that the VP8X chunk, if present, is up-to-date. 
336// That is, the mux object hasn't been modified since the last call to 
337// WebPMuxAssemble() or WebPMuxCreate(). 
338// Parameters: 
339// mux - (in) object from which the canvas size is to be fetched 
340// width - (out) canvas width 
341// height - (out) canvas height 
342// Returns: 
343// WEBP_MUX_INVALID_ARGUMENT - if mux, width or height is NULL. 
344// WEBP_MUX_BAD_DATA - if VP8X/VP8/VP8L chunk or canvas size is invalid. 
345// WEBP_MUX_OK - on success. 
346WEBP_EXTERN WebPMuxError WebPMuxGetCanvasSize(const WebPMux* mux, 
347 int* width, int* height); 
348 
349// Gets the feature flags from the mux object. 
350// Note: This method assumes that the VP8X chunk, if present, is up-to-date. 
351// That is, the mux object hasn't been modified since the last call to 
352// WebPMuxAssemble() or WebPMuxCreate(). 
353// Parameters: 
354// mux - (in) object from which the features are to be fetched 
355// flags - (out) the flags specifying which features are present in the 
356// mux object. This will be an OR of various flag values. 
357// Enum 'WebPFeatureFlags' can be used to test individual flag values. 
358// Returns: 
359// WEBP_MUX_INVALID_ARGUMENT - if mux or flags is NULL. 
360// WEBP_MUX_BAD_DATA - if VP8X/VP8/VP8L chunk or canvas size is invalid. 
361// WEBP_MUX_OK - on success. 
362WEBP_EXTERN WebPMuxError WebPMuxGetFeatures(const WebPMux* mux, 
363 uint32_t* flags); 
364 
365// Gets number of chunks with the given 'id' in the mux object. 
366// Parameters: 
367// mux - (in) object from which the info is to be fetched 
368// id - (in) chunk id specifying the type of chunk 
369// num_elements - (out) number of chunks with the given chunk id 
370// Returns: 
371// WEBP_MUX_INVALID_ARGUMENT - if mux, or num_elements is NULL. 
372// WEBP_MUX_OK - on success. 
373WEBP_EXTERN WebPMuxError WebPMuxNumChunks(const WebPMux* mux, 
374 WebPChunkId id, int* num_elements); 
375 
376// Assembles all chunks in WebP RIFF format and returns in 'assembled_data'. 
377// This function also validates the mux object. 
378// Note: The content of 'assembled_data' will be ignored and overwritten. 
379// Also, the content of 'assembled_data' is allocated using WebPMalloc(), and 
380// NOT owned by the 'mux' object. It MUST be deallocated by the caller by 
381// calling WebPDataClear(). It's always safe to call WebPDataClear() upon 
382// return, even in case of error. 
383// Parameters: 
384// mux - (in/out) object whose chunks are to be assembled 
385// assembled_data - (out) assembled WebP data 
386// Returns: 
387// WEBP_MUX_BAD_DATA - if mux object is invalid. 
388// WEBP_MUX_INVALID_ARGUMENT - if mux or assembled_data is NULL. 
389// WEBP_MUX_MEMORY_ERROR - on memory allocation error. 
390// WEBP_MUX_OK - on success. 
391WEBP_EXTERN WebPMuxError WebPMuxAssemble(WebPMux* mux, 
392 WebPData* assembled_data); 
393 
394//------------------------------------------------------------------------------ 
395// WebPAnimEncoder API 
396// 
397// This API allows encoding (possibly) animated WebP images. 
398// 
399// Code Example: 
400/* 
401 WebPAnimEncoderOptions enc_options; 
402 WebPAnimEncoderOptionsInit(&enc_options); 
403 // Tune 'enc_options' as needed. 
404 WebPAnimEncoder* enc = WebPAnimEncoderNew(width, height, &enc_options); 
405 while(<there are more frames>) { 
406 WebPConfig config; 
407 WebPConfigInit(&config); 
408 // Tune 'config' as needed. 
409 WebPAnimEncoderAdd(enc, frame, timestamp_ms, &config); 
410 } 
411 WebPAnimEncoderAdd(enc, NULL, timestamp_ms, NULL); 
412 WebPAnimEncoderAssemble(enc, webp_data); 
413 WebPAnimEncoderDelete(enc); 
414 // Write the 'webp_data' to a file, or re-mux it further. 
415*/ 
416 
417typedef struct WebPAnimEncoder WebPAnimEncoder; // Main opaque object. 
418 
419// Forward declarations. Defined in encode.h. 
420struct WebPPicture; 
421struct WebPConfig; 
422 
423// Global options. 
424struct WebPAnimEncoderOptions { 
425 WebPMuxAnimParams anim_params; // Animation parameters. 
426 int minimize_size; // If true, minimize the output size (slow). Implicitly 
427 // disables key-frame insertion. 
428 int kmin; 
429 int kmax; // Minimum and maximum distance between consecutive key 
430 // frames in the output. The library may insert some key 
431 // frames as needed to satisfy this criteria. 
432 // Note that these conditions should hold: kmax > kmin 
433 // and kmin >= kmax / 2 + 1. Also, if kmax <= 0, then 
434 // key-frame insertion is disabled; and if kmax == 1, 
435 // then all frames will be key-frames (kmin value does 
436 // not matter for these special cases). 
437 int allow_mixed; // If true, use mixed compression mode; may choose 
438 // either lossy and lossless for each frame. 
439 int verbose; // If true, print info and warning messages to stderr. 
440 
441 uint32_t padding[4]; // Padding for later use. 
442}; 
443 
444// Internal, version-checked, entry point. 
445WEBP_EXTERN int WebPAnimEncoderOptionsInitInternal( 
446 WebPAnimEncoderOptions*, int); 
447 
448// Should always be called, to initialize a fresh WebPAnimEncoderOptions 
449// structure before modification. Returns false in case of version mismatch. 
450// WebPAnimEncoderOptionsInit() must have succeeded before using the 
451// 'enc_options' object. 
452static WEBP_INLINE int WebPAnimEncoderOptionsInit( 
453 WebPAnimEncoderOptions* enc_options) { 
454 return WebPAnimEncoderOptionsInitInternal(enc_options, WEBP_MUX_ABI_VERSION); 
455} 
456 
457// Internal, version-checked, entry point. 
458WEBP_EXTERN WebPAnimEncoder* WebPAnimEncoderNewInternal( 
459 int, int, const WebPAnimEncoderOptions*, int); 
460 
461// Creates and initializes a WebPAnimEncoder object. 
462// Parameters: 
463// width/height - (in) canvas width and height of the animation. 
464// enc_options - (in) encoding options; can be passed NULL to pick 
465// reasonable defaults. 
466// Returns: 
467// A pointer to the newly created WebPAnimEncoder object. 
468// Or NULL in case of memory error. 
469static WEBP_INLINE WebPAnimEncoder* WebPAnimEncoderNew( 
470 int width, int height, const WebPAnimEncoderOptions* enc_options) { 
471 return WebPAnimEncoderNewInternal(width, height, enc_options, 
472 WEBP_MUX_ABI_VERSION); 
473} 
474 
475// Optimize the given frame for WebP, encode it and add it to the 
476// WebPAnimEncoder object. 
477// The last call to 'WebPAnimEncoderAdd' should be with frame = NULL, which 
478// indicates that no more frames are to be added. This call is also used to 
479// determine the duration of the last frame. 
480// Parameters: 
481// enc - (in/out) object to which the frame is to be added. 
482// frame - (in/out) frame data in ARGB or YUV(A) format. If it is in YUV(A) 
483// format, it will be converted to ARGB, which incurs a small loss. 
484// timestamp_ms - (in) timestamp of this frame in milliseconds. 
485// Duration of a frame would be calculated as 
486// "timestamp of next frame - timestamp of this frame". 
487// Hence, timestamps should be in non-decreasing order. 
488// config - (in) encoding options; can be passed NULL to pick 
489// reasonable defaults. 
490// Returns: 
491// On error, returns false and frame->error_code is set appropriately. 
492// Otherwise, returns true. 
493WEBP_EXTERN int WebPAnimEncoderAdd( 
494 WebPAnimEncoder* enc, struct WebPPicture* frame, int timestamp_ms, 
495 const struct WebPConfig* config); 
496 
497// Assemble all frames added so far into a WebP bitstream. 
498// This call should be preceded by a call to 'WebPAnimEncoderAdd' with 
499// frame = NULL; if not, the duration of the last frame will be internally 
500// estimated. 
501// Parameters: 
502// enc - (in/out) object from which the frames are to be assembled. 
503// webp_data - (out) generated WebP bitstream. 
504// Returns: 
505// True on success. 
506WEBP_EXTERN int WebPAnimEncoderAssemble(WebPAnimEncoder* enc, 
507 WebPData* webp_data); 
508 
509// Get error string corresponding to the most recent call using 'enc'. The 
510// returned string is owned by 'enc' and is valid only until the next call to 
511// WebPAnimEncoderAdd() or WebPAnimEncoderAssemble() or WebPAnimEncoderDelete(). 
512// Parameters: 
513// enc - (in/out) object from which the error string is to be fetched. 
514// Returns: 
515// NULL if 'enc' is NULL. Otherwise, returns the error string if the last call 
516// to 'enc' had an error, or an empty string if the last call was a success. 
517WEBP_EXTERN const char* WebPAnimEncoderGetError(WebPAnimEncoder* enc); 
518 
519// Deletes the WebPAnimEncoder object. 
520// Parameters: 
521// enc - (in/out) object to be deleted 
522WEBP_EXTERN void WebPAnimEncoderDelete(WebPAnimEncoder* enc); 
523 
524//------------------------------------------------------------------------------ 
525 
526#ifdef __cplusplus 
527} // extern "C" 
528#endif 
529 
530#endif // WEBP_WEBP_MUX_H_ 
531