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 // Internal header for mux library.
11 //
12 // Author: Urvang (urvang@google.com)
13
14 #ifndef WEBP_MUX_MUXI_H_
15 #define WEBP_MUX_MUXI_H_
16
17 #include <stdlib.h>
18 #include "../dec/vp8i_dec.h"
19 #include "../dec/vp8li_dec.h"
20 #include "../webp/mux.h"
21
22 #ifdef __cplusplus
23 extern "C" {
24 #endif
25
26 //------------------------------------------------------------------------------
27 // Defines and constants.
28
29 #define MUX_MAJ_VERSION 0
30 #define MUX_MIN_VERSION 4
31 #define MUX_REV_VERSION 0
32
33 // Chunk object.
34 typedef struct WebPChunk WebPChunk;
35 struct WebPChunk {
36 uint32_t tag_;
37 int owner_; // True if *data_ memory is owned internally.
38 // VP8X, ANIM, and other internally created chunks
39 // like ANMF are always owned.
40 WebPData data_;
41 WebPChunk* next_;
42 };
43
44 // MuxImage object. Store a full WebP image (including ANMF chunk, ALPH
45 // chunk and VP8/VP8L chunk),
46 typedef struct WebPMuxImage WebPMuxImage;
47 struct WebPMuxImage {
48 WebPChunk* header_; // Corresponds to WEBP_CHUNK_ANMF.
49 WebPChunk* alpha_; // Corresponds to WEBP_CHUNK_ALPHA.
50 WebPChunk* img_; // Corresponds to WEBP_CHUNK_IMAGE.
51 WebPChunk* unknown_; // Corresponds to WEBP_CHUNK_UNKNOWN.
52 int width_;
53 int height_;
54 int has_alpha_; // Through ALPH chunk or as part of VP8L.
55 int is_partial_; // True if only some of the chunks are filled.
56 WebPMuxImage* next_;
57 };
58
59 // Main mux object. Stores data chunks.
60 struct WebPMux {
61 WebPMuxImage* images_;
62 WebPChunk* iccp_;
63 WebPChunk* exif_;
64 WebPChunk* xmp_;
65 WebPChunk* anim_;
66 WebPChunk* vp8x_;
67
68 WebPChunk* unknown_;
69 int canvas_width_;
70 int canvas_height_;
71 };
72
73 // CHUNK_INDEX enum: used for indexing within 'kChunks' (defined below) only.
74 // Note: the reason for having two enums ('WebPChunkId' and 'CHUNK_INDEX') is to
75 // allow two different chunks to have the same id (e.g. WebPChunkId
76 // 'WEBP_CHUNK_IMAGE' can correspond to CHUNK_INDEX 'IDX_VP8' or 'IDX_VP8L').
77 typedef enum {
78 IDX_VP8X = 0,
79 IDX_ICCP,
80 IDX_ANIM,
81 IDX_ANMF,
82 IDX_ALPHA,
83 IDX_VP8,
84 IDX_VP8L,
85 IDX_EXIF,
86 IDX_XMP,
87 IDX_UNKNOWN,
88
89 IDX_NIL,
90 IDX_LAST_CHUNK
91 } CHUNK_INDEX;
92
93 #define NIL_TAG 0x00000000u // To signal void chunk.
94
95 typedef struct {
96 uint32_t tag;
97 WebPChunkId id;
98 uint32_t size;
99 } ChunkInfo;
100
101 extern const ChunkInfo kChunks[IDX_LAST_CHUNK];
102
103 //------------------------------------------------------------------------------
104 // Chunk object management.
105
106 // Initialize.
107 void ChunkInit(WebPChunk* const chunk);
108
109 // Get chunk index from chunk tag. Returns IDX_UNKNOWN if not found.
110 CHUNK_INDEX ChunkGetIndexFromTag(uint32_t tag);
111
112 // Get chunk id from chunk tag. Returns WEBP_CHUNK_UNKNOWN if not found.
113 WebPChunkId ChunkGetIdFromTag(uint32_t tag);
114
115 // Convert a fourcc string to a tag.
116 uint32_t ChunkGetTagFromFourCC(const char fourcc[4]);
117
118 // Get chunk index from fourcc. Returns IDX_UNKNOWN if given fourcc is unknown.
119 CHUNK_INDEX ChunkGetIndexFromFourCC(const char fourcc[4]);
120
121 // Search for nth chunk with given 'tag' in the chunk list.
122 // nth = 0 means "last of the list".
123 WebPChunk* ChunkSearchList(WebPChunk* first, uint32_t nth, uint32_t tag);
124
125 // Fill the chunk with the given data.
126 WebPMuxError ChunkAssignData(WebPChunk* chunk, const WebPData* const data,
127 int copy_data, uint32_t tag);
128
129 // Sets 'chunk' at nth position in the 'chunk_list'.
130 // nth = 0 has the special meaning "last of the list".
131 // On success ownership is transferred from 'chunk' to the 'chunk_list'.
132 WebPMuxError ChunkSetNth(WebPChunk* chunk, WebPChunk** chunk_list,
133 uint32_t nth);
134
135 // Releases chunk and returns chunk->next_.
136 WebPChunk* ChunkRelease(WebPChunk* const chunk);
137
138 // Deletes given chunk & returns chunk->next_.
139 WebPChunk* ChunkDelete(WebPChunk* const chunk);
140
141 // Deletes all chunks in the given chunk list.
142 void ChunkListDelete(WebPChunk** const chunk_list);
143
144 // Returns size of the chunk including chunk header and padding byte (if any).
SizeWithPadding(size_t chunk_size)145 static WEBP_INLINE size_t SizeWithPadding(size_t chunk_size) {
146 return CHUNK_HEADER_SIZE + ((chunk_size + 1) & ~1U);
147 }
148
149 // Size of a chunk including header and padding.
ChunkDiskSize(const WebPChunk * chunk)150 static WEBP_INLINE size_t ChunkDiskSize(const WebPChunk* chunk) {
151 const size_t data_size = chunk->data_.size;
152 assert(data_size < MAX_CHUNK_PAYLOAD);
153 return SizeWithPadding(data_size);
154 }
155
156 // Total size of a list of chunks.
157 size_t ChunkListDiskSize(const WebPChunk* chunk_list);
158
159 // Write out the given list of chunks into 'dst'.
160 uint8_t* ChunkListEmit(const WebPChunk* chunk_list, uint8_t* dst);
161
162 //------------------------------------------------------------------------------
163 // MuxImage object management.
164
165 // Initialize.
166 void MuxImageInit(WebPMuxImage* const wpi);
167
168 // Releases image 'wpi' and returns wpi->next.
169 WebPMuxImage* MuxImageRelease(WebPMuxImage* const wpi);
170
171 // Delete image 'wpi' and return the next image in the list or NULL.
172 // 'wpi' can be NULL.
173 WebPMuxImage* MuxImageDelete(WebPMuxImage* const wpi);
174
175 // Count number of images matching the given tag id in the 'wpi_list'.
176 // If id == WEBP_CHUNK_NIL, all images will be matched.
177 int MuxImageCount(const WebPMuxImage* wpi_list, WebPChunkId id);
178
179 // Update width/height/has_alpha info from chunks within wpi.
180 // Also remove ALPH chunk if not needed.
181 int MuxImageFinalize(WebPMuxImage* const wpi);
182
183 // Check if given ID corresponds to an image related chunk.
IsWPI(WebPChunkId id)184 static WEBP_INLINE int IsWPI(WebPChunkId id) {
185 switch (id) {
186 case WEBP_CHUNK_ANMF:
187 case WEBP_CHUNK_ALPHA:
188 case WEBP_CHUNK_IMAGE: return 1;
189 default: return 0;
190 }
191 }
192
193 // Pushes 'wpi' at the end of 'wpi_list'.
194 WebPMuxError MuxImagePush(const WebPMuxImage* wpi, WebPMuxImage** wpi_list);
195
196 // Delete nth image in the image list.
197 WebPMuxError MuxImageDeleteNth(WebPMuxImage** wpi_list, uint32_t nth);
198
199 // Get nth image in the image list.
200 WebPMuxError MuxImageGetNth(const WebPMuxImage** wpi_list, uint32_t nth,
201 WebPMuxImage** wpi);
202
203 // Total size of the given image.
204 size_t MuxImageDiskSize(const WebPMuxImage* const wpi);
205
206 // Write out the given image into 'dst'.
207 uint8_t* MuxImageEmit(const WebPMuxImage* const wpi, uint8_t* dst);
208
209 //------------------------------------------------------------------------------
210 // Helper methods for mux.
211
212 // Checks if the given image list contains at least one image with alpha.
213 int MuxHasAlpha(const WebPMuxImage* images);
214
215 // Write out RIFF header into 'data', given total data size 'size'.
216 uint8_t* MuxEmitRiffHeader(uint8_t* const data, size_t size);
217
218 // Returns the list where chunk with given ID is to be inserted in mux.
219 WebPChunk** MuxGetChunkListFromId(const WebPMux* mux, WebPChunkId id);
220
221 // Validates the given mux object.
222 WebPMuxError MuxValidate(const WebPMux* const mux);
223
224 //------------------------------------------------------------------------------
225
226 #ifdef __cplusplus
227 } // extern "C"
228 #endif
229
230 #endif /* WEBP_MUX_MUXI_H_ */
231