summaryrefslogtreecommitdiff
path: root/media/libwebp/webp/mux.h
blob: 28bb4a41c9e4d30b4497a022e69de3f8cf322746 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
// Copyright 2011 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.
// -----------------------------------------------------------------------------
//
//  RIFF container manipulation and encoding for WebP images.
//
// Authors: Urvang (urvang@google.com)
//          Vikas (vikasa@google.com)

#ifndef WEBP_WEBP_MUX_H_
#define WEBP_WEBP_MUX_H_

#include "./mux_types.h"

#ifdef __cplusplus
extern "C" {
#endif

#define WEBP_MUX_ABI_VERSION 0x0108        // MAJOR(8b) + MINOR(8b)

//------------------------------------------------------------------------------
// Mux API
//
// This API allows manipulation of WebP container images containing features
// like color profile, metadata, animation.
//
// Code Example#1: Create a WebPMux object 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, "XMP ", &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);
*/

// Note: forward declaring enumerations is not allowed in (strict) C and C++,
// the types are left here for reference.
// typedef enum WebPMuxError WebPMuxError;
// typedef enum WebPChunkId WebPChunkId;
typedef struct WebPMux WebPMux;   // main opaque object.
typedef struct WebPMuxFrameInfo WebPMuxFrameInfo;
typedef struct WebPMuxAnimParams WebPMuxAnimParams;
typedef struct WebPAnimEncoderOptions WebPAnimEncoderOptions;

// Error codes
typedef 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
} WebPMuxError;

// IDs for different types of chunks.
typedef enum WebPChunkId {
  WEBP_CHUNK_VP8X,        // VP8X
  WEBP_CHUNK_ICCP,        // ICCP
  WEBP_CHUNK_ANIM,        // ANIM
  WEBP_CHUNK_ANMF,        // ANMF
  WEBP_CHUNK_DEPRECATED,  // (deprecated from FRGM)
  WEBP_CHUNK_ALPHA,       // ALPH
  WEBP_CHUNK_IMAGE,       // VP8/VP8L
  WEBP_CHUNK_EXIF,        // EXIF
  WEBP_CHUNK_XMP,         // XMP
  WEBP_CHUNK_UNKNOWN,     // Other chunks.
  WEBP_CHUNK_NIL
} WebPChunkId;

//------------------------------------------------------------------------------

// Returns the version number of the mux library, packed in hexadecimal using
// 8bits for each of major/minor/revision. E.g: v2.5.7 is 0x020507.
WEBP_EXTERN int WebPGetMuxVersion(void);

//------------------------------------------------------------------------------
// 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.
//   Or NULL in case of memory error.
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
//               object 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", "VP8 ", "VP8L" and "ALPH").
// To add, get and delete images, use 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", "XMP ", "EXIF" etc.
//   chunk_data - (in) the chunk data to be added
//   copy_data - (in) value 1 indicates given data WILL be copied to the mux
//               object 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", "XMP ", "EXIF" etc.
//   chunk_data - (out) returned chunk data
// Returns:
//   WEBP_MUX_INVALID_ARGUMENT - if 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", "XMP ", "EXIF" 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.
struct WebPMuxFrameInfo {
  WebPData    bitstream;  // image data: can 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
                          // or WEBP_CHUNK_IMAGE
  WebPMuxAnimDispose dispose_method;  // Disposal method for the frame.
  WebPMuxAnimBlend   blend_method;    // Blend operation for the frame.
  uint32_t    pad[1];     // padding for later use
};

// Sets the (non-animated) image in the mux object.
// Note: Any existing images (including frames) will be removed.
// Parameters:
//   mux - (in/out) object in which the image is to be set
//   bitstream - (in) can be a raw VP8/VP8L bitstream or a single-image
//               WebP file (non-animated)
//   copy_data - (in) value 1 indicates given data WILL be copied to the mux
//               object 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 WEBP_CHUNK_ANMF
//        (2) For setting a non-animated 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
//               object 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_MEMORY_ERROR - on memory allocation error.
//   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.

// Animation parameters.
struct WebPMuxAnimParams {
  uint32_t bgcolor;  // Background color of the canvas stored (in MSB order) as:
                     // Bits 00 to 07: Alpha.
                     // Bits 08 to 15: Red.
                     // Bits 16 to 23: Green.
                     // Bits 24 to 31: Blue.
  int loop_count;    // Number of times to repeat the animation [0 = infinite].
};

// Sets the animation parameters in the mux object. Any existing ANIM chunks
// will be removed.
// Parameters:
//   mux - (in/out) object in which ANIM chunk is to be set/added
//   params - (in) animation parameters.
// Returns:
//   WEBP_MUX_INVALID_ARGUMENT - if mux or params is NULL.
//   WEBP_MUX_MEMORY_ERROR - on memory allocation error.
//   WEBP_MUX_OK - on success.
WEBP_EXTERN WebPMuxError WebPMuxSetAnimationParams(
    WebPMux* mux, const WebPMuxAnimParams* params);

// Gets the animation parameters from the mux object.
// Parameters:
//   mux - (in) object from which the animation parameters to be fetched
//   params - (out) animation parameters extracted from the ANIM chunk
// Returns:
//   WEBP_MUX_INVALID_ARGUMENT - if mux or params is NULL.
//   WEBP_MUX_NOT_FOUND - if ANIM chunk is not present in mux object.
//   WEBP_MUX_OK - on success.
WEBP_EXTERN WebPMuxError WebPMuxGetAnimationParams(
    const WebPMux* mux, WebPMuxAnimParams* params);

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

// Sets the canvas size for the mux object. The width and height can be
// specified explicitly or left as zero (0, 0).
// * When width and height are specified explicitly, then this frame bound is
//   enforced during subsequent calls to WebPMuxAssemble() and an error is
//   reported if any animated frame does not completely fit within the canvas.
// * When unspecified (0, 0), the constructed canvas will get the frame bounds
//   from the bounding-box over all frames after calling WebPMuxAssemble().
// Parameters:
//   mux - (in) object to which the canvas size is to be set
//   width - (in) canvas width
//   height - (in) canvas height
// Returns:
//   WEBP_MUX_INVALID_ARGUMENT - if mux is NULL; or
//                               width or height are invalid or out of bounds
//   WEBP_MUX_OK - on success.
WEBP_EXTERN WebPMuxError WebPMuxSetCanvasSize(WebPMux* mux,
                                              int width, int height);

// Gets the canvas size from the mux object.
// Note: This method assumes that the VP8X chunk, if present, is up-to-date.
// That is, the mux object hasn't been modified since the last call to
// WebPMuxAssemble() or WebPMuxCreate().
// Parameters:
//   mux - (in) object from which the canvas size is to be fetched
//   width - (out) canvas width
//   height - (out) canvas height
// Returns:
//   WEBP_MUX_INVALID_ARGUMENT - if mux, width or height is NULL.
//   WEBP_MUX_BAD_DATA - if VP8X/VP8/VP8L chunk or canvas size is invalid.
//   WEBP_MUX_OK - on success.
WEBP_EXTERN WebPMuxError WebPMuxGetCanvasSize(const WebPMux* mux,
                                              int* width, int* height);

// Gets the feature flags from the mux object.
// Note: This method assumes that the VP8X chunk, if present, is up-to-date.
// That is, the mux object hasn't been modified since the last call to
// WebPMuxAssemble() or WebPMuxCreate().
// 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_BAD_DATA - if VP8X/VP8/VP8L chunk or canvas size is invalid.
//   WEBP_MUX_OK - on success.
WEBP_EXTERN WebPMuxError WebPMuxGetFeatures(const WebPMux* mux,
                                            uint32_t* flags);

// Gets number of chunks with the given 'id' 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 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(). It's always safe to call WebPDataClear() upon return,
// even in case of error.
// 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 mux or assembled_data is NULL.
//   WEBP_MUX_MEMORY_ERROR - on memory allocation error.
//   WEBP_MUX_OK - on success.
WEBP_EXTERN WebPMuxError WebPMuxAssemble(WebPMux* mux,
                                         WebPData* assembled_data);

//------------------------------------------------------------------------------
// WebPAnimEncoder API
//
// This API allows encoding (possibly) animated WebP images.
//
// Code Example:
/*
  WebPAnimEncoderOptions enc_options;
  WebPAnimEncoderOptionsInit(&enc_options);
  // Tune 'enc_options' as needed.
  WebPAnimEncoder* enc = WebPAnimEncoderNew(width, height, &enc_options);
  while(<there are more frames>) {
    WebPConfig config;
    WebPConfigInit(&config);
    // Tune 'config' as needed.
    WebPAnimEncoderAdd(enc, frame, timestamp_ms, &config);
  }
  WebPAnimEncoderAdd(enc, NULL, timestamp_ms, NULL);
  WebPAnimEncoderAssemble(enc, webp_data);
  WebPAnimEncoderDelete(enc);
  // Write the 'webp_data' to a file, or re-mux it further.
*/

typedef struct WebPAnimEncoder WebPAnimEncoder;  // Main opaque object.

// Forward declarations. Defined in encode.h.
struct WebPPicture;
struct WebPConfig;

// Global options.
struct WebPAnimEncoderOptions {
  WebPMuxAnimParams anim_params;  // Animation parameters.
  int minimize_size;    // If true, minimize the output size (slow). Implicitly
                        // disables key-frame insertion.
  int kmin;
  int kmax;             // Minimum and maximum distance between consecutive key
                        // frames in the output. The library may insert some key
                        // frames as needed to satisfy this criteria.
                        // Note that these conditions should hold: kmax > kmin
                        // and kmin >= kmax / 2 + 1. Also, if kmax <= 0, then
                        // key-frame insertion is disabled; and if kmax == 1,
                        // then all frames will be key-frames (kmin value does
                        // not matter for these special cases).
  int allow_mixed;      // If true, use mixed compression mode; may choose
                        // either lossy and lossless for each frame.
  int verbose;          // If true, print info and warning messages to stderr.

  uint32_t padding[4];  // Padding for later use.
};

// Internal, version-checked, entry point.
WEBP_EXTERN int WebPAnimEncoderOptionsInitInternal(
    WebPAnimEncoderOptions*, int);

// Should always be called, to initialize a fresh WebPAnimEncoderOptions
// structure before modification. Returns false in case of version mismatch.
// WebPAnimEncoderOptionsInit() must have succeeded before using the
// 'enc_options' object.
static WEBP_INLINE int WebPAnimEncoderOptionsInit(
    WebPAnimEncoderOptions* enc_options) {
  return WebPAnimEncoderOptionsInitInternal(enc_options, WEBP_MUX_ABI_VERSION);
}

// Internal, version-checked, entry point.
WEBP_EXTERN WebPAnimEncoder* WebPAnimEncoderNewInternal(
    int, int, const WebPAnimEncoderOptions*, int);

// Creates and initializes a WebPAnimEncoder object.
// Parameters:
//   width/height - (in) canvas width and height of the animation.
//   enc_options - (in) encoding options; can be passed NULL to pick
//                      reasonable defaults.
// Returns:
//   A pointer to the newly created WebPAnimEncoder object.
//   Or NULL in case of memory error.
static WEBP_INLINE WebPAnimEncoder* WebPAnimEncoderNew(
    int width, int height, const WebPAnimEncoderOptions* enc_options) {
  return WebPAnimEncoderNewInternal(width, height, enc_options,
                                    WEBP_MUX_ABI_VERSION);
}

// Optimize the given frame for WebP, encode it and add it to the
// WebPAnimEncoder object.
// The last call to 'WebPAnimEncoderAdd' should be with frame = NULL, which
// indicates that no more frames are to be added. This call is also used to
// determine the duration of the last frame.
// Parameters:
//   enc - (in/out) object to which the frame is to be added.
//   frame - (in/out) frame data in ARGB or YUV(A) format. If it is in YUV(A)
//           format, it will be converted to ARGB, which incurs a small loss.
//   timestamp_ms - (in) timestamp of this frame in milliseconds.
//                       Duration of a frame would be calculated as
//                       "timestamp of next frame - timestamp of this frame".
//                       Hence, timestamps should be in non-decreasing order.
//   config - (in) encoding options; can be passed NULL to pick
//            reasonable defaults.
// Returns:
//   On error, returns false and frame->error_code is set appropriately.
//   Otherwise, returns true.
WEBP_EXTERN int WebPAnimEncoderAdd(
    WebPAnimEncoder* enc, struct WebPPicture* frame, int timestamp_ms,
    const struct WebPConfig* config);

// Assemble all frames added so far into a WebP bitstream.
// This call should be preceded by  a call to 'WebPAnimEncoderAdd' with
// frame = NULL; if not, the duration of the last frame will be internally
// estimated.
// Parameters:
//   enc - (in/out) object from which the frames are to be assembled.
//   webp_data - (out) generated WebP bitstream.
// Returns:
//   True on success.
WEBP_EXTERN int WebPAnimEncoderAssemble(WebPAnimEncoder* enc,
                                        WebPData* webp_data);

// Get error string corresponding to the most recent call using 'enc'. The
// returned string is owned by 'enc' and is valid only until the next call to
// WebPAnimEncoderAdd() or WebPAnimEncoderAssemble() or WebPAnimEncoderDelete().
// Parameters:
//   enc - (in/out) object from which the error string is to be fetched.
// Returns:
//   NULL if 'enc' is NULL. Otherwise, returns the error string if the last call
//   to 'enc' had an error, or an empty string if the last call was a success.
WEBP_EXTERN const char* WebPAnimEncoderGetError(WebPAnimEncoder* enc);

// Deletes the WebPAnimEncoder object.
// Parameters:
//   enc - (in/out) object to be deleted
WEBP_EXTERN void WebPAnimEncoderDelete(WebPAnimEncoder* enc);

//------------------------------------------------------------------------------

#ifdef __cplusplus
}    // extern "C"
#endif

#endif  /* WEBP_WEBP_MUX_H_ */