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 <assert.h>
18 #include <stdlib.h>
19 #include "src/dec/vp8i_dec.h"
20 #include "src/dec/vp8li_dec.h"
21 #include "src/webp/mux.h"
22
23 #ifdef __cplusplus
24 extern "C" {
25 #endif
26
27 //------------------------------------------------------------------------------
28 // Defines and constants.
29
30 #define MUX_MAJ_VERSION 1
31 #define MUX_MIN_VERSION 1
32 #define MUX_REV_VERSION 0
33
34 // Chunk object.
35 typedef struct WebPChunk WebPChunk;
36 struct WebPChunk {
37 uint32_t tag_;
38 int owner_; // True if *data_ memory is owned internally.
39 // VP8X, ANIM, and other internally created chunks
40 // like ANMF are always owned.
41 WebPData data_;
42 WebPChunk* next_;
43 };
44
45 // MuxImage object. Store a full WebP image (including ANMF chunk, ALPH
46 // chunk and VP8/VP8L chunk),
47 typedef struct WebPMuxImage WebPMuxImage;
48 struct WebPMuxImage {
49 WebPChunk* header_; // Corresponds to WEBP_CHUNK_ANMF.
50 WebPChunk* alpha_; // Corresponds to WEBP_CHUNK_ALPHA.
51 WebPChunk* img_; // Corresponds to WEBP_CHUNK_IMAGE.
52 WebPChunk* unknown_; // Corresponds to WEBP_CHUNK_UNKNOWN.
53 int width_;
54 int height_;
55 int has_alpha_; // Through ALPH chunk or as part of VP8L.
56 int is_partial_; // True if only some of the chunks are filled.
57 WebPMuxImage* next_;
58 };
59
60 // Main mux object. Stores data chunks.
61 struct WebPMux {
62 WebPMuxImage* images_;
63 WebPChunk* iccp_;
64 WebPChunk* exif_;
65 WebPChunk* xmp_;
66 WebPChunk* anim_;
67 WebPChunk* vp8x_;
68
69 WebPChunk* unknown_;
70 int canvas_width_;
71 int canvas_height_;
72 };
73
74 // CHUNK_INDEX enum: used for indexing within 'kChunks' (defined below) only.
75 // Note: the reason for having two enums ('WebPChunkId' and 'CHUNK_INDEX') is to
76 // allow two different chunks to have the same id (e.g. WebPChunkId
77 // 'WEBP_CHUNK_IMAGE' can correspond to CHUNK_INDEX 'IDX_VP8' or 'IDX_VP8L').
78 typedef enum {
79 IDX_VP8X = 0,
80 IDX_ICCP,
81 IDX_ANIM,
82 IDX_ANMF,
83 IDX_ALPHA,
84 IDX_VP8,
85 IDX_VP8L,
86 IDX_EXIF,
87 IDX_XMP,
88 IDX_UNKNOWN,
89
90 IDX_NIL,
91 IDX_LAST_CHUNK
92 } CHUNK_INDEX;
93
94 #define NIL_TAG 0x00000000u // To signal void chunk.
95
96 typedef struct {
97 uint32_t tag;
98 WebPChunkId id;
99 uint32_t size;
100 } ChunkInfo;
101
102 extern const ChunkInfo kChunks[IDX_LAST_CHUNK];
103
104 //------------------------------------------------------------------------------
105 // Chunk object management.
106
107 // Initialize.
108 void ChunkInit(WebPChunk* const chunk);
109
110 // Get chunk index from chunk tag. Returns IDX_UNKNOWN if not found.
111 CHUNK_INDEX ChunkGetIndexFromTag(uint32_t tag);
112
113 // Get chunk id from chunk tag. Returns WEBP_CHUNK_UNKNOWN if not found.
114 WebPChunkId ChunkGetIdFromTag(uint32_t tag);
115
116 // Convert a fourcc string to a tag.
117 uint32_t ChunkGetTagFromFourCC(const char fourcc[4]);
118
119 // Get chunk index from fourcc. Returns IDX_UNKNOWN if given fourcc is unknown.
120 CHUNK_INDEX ChunkGetIndexFromFourCC(const char fourcc[4]);
121
122 // Search for nth chunk with given 'tag' in the chunk list.
123 // nth = 0 means "last of the list".
124 WebPChunk* ChunkSearchList(WebPChunk* first, uint32_t nth, uint32_t tag);
125
126 // Fill the chunk with the given data.
127 WebPMuxError ChunkAssignData(WebPChunk* chunk, const WebPData* const data,
128 int copy_data, uint32_t tag);
129
130 // Sets 'chunk' as the only element in 'chunk_list' if it is empty.
131 // On success ownership is transferred from 'chunk' to the 'chunk_list'.
132 WebPMuxError ChunkSetHead(WebPChunk* const chunk, WebPChunk** const chunk_list);
133 // Sets 'chunk' at last position in the 'chunk_list'.
134 // On success ownership is transferred from 'chunk' to the 'chunk_list'.
135 // *chunk_list also points towards the last valid element of the initial
136 // *chunk_list.
137 WebPMuxError ChunkAppend(WebPChunk* const chunk, WebPChunk*** const chunk_list);
138
139 // Releases chunk and returns chunk->next_.
140 WebPChunk* ChunkRelease(WebPChunk* const chunk);
141
142 // Deletes given chunk & returns chunk->next_.
143 WebPChunk* ChunkDelete(WebPChunk* const chunk);
144
145 // Deletes all chunks in the given chunk list.
146 void ChunkListDelete(WebPChunk** const chunk_list);
147
148 // Returns size of the chunk including chunk header and padding byte (if any).
SizeWithPadding(size_t chunk_size)149 static WEBP_INLINE size_t SizeWithPadding(size_t chunk_size) {
150 assert(chunk_size <= MAX_CHUNK_PAYLOAD);
151 return CHUNK_HEADER_SIZE + ((chunk_size + 1) & ~1U);
152 }
153
154 // Size of a chunk including header and padding.
ChunkDiskSize(const WebPChunk * chunk)155 static WEBP_INLINE size_t ChunkDiskSize(const WebPChunk* chunk) {
156 const size_t data_size = chunk->data_.size;
157 return SizeWithPadding(data_size);
158 }
159
160 // Total size of a list of chunks.
161 size_t ChunkListDiskSize(const WebPChunk* chunk_list);
162
163 // Write out the given list of chunks into 'dst'.
164 uint8_t* ChunkListEmit(const WebPChunk* chunk_list, uint8_t* dst);
165
166 //------------------------------------------------------------------------------
167 // MuxImage object management.
168
169 // Initialize.
170 void MuxImageInit(WebPMuxImage* const wpi);
171
172 // Releases image 'wpi' and returns wpi->next.
173 WebPMuxImage* MuxImageRelease(WebPMuxImage* const wpi);
174
175 // Delete image 'wpi' and return the next image in the list or NULL.
176 // 'wpi' can be NULL.
177 WebPMuxImage* MuxImageDelete(WebPMuxImage* const wpi);
178
179 // Count number of images matching the given tag id in the 'wpi_list'.
180 // If id == WEBP_CHUNK_NIL, all images will be matched.
181 int MuxImageCount(const WebPMuxImage* wpi_list, WebPChunkId id);
182
183 // Update width/height/has_alpha info from chunks within wpi.
184 // Also remove ALPH chunk if not needed.
185 int MuxImageFinalize(WebPMuxImage* const wpi);
186
187 // Check if given ID corresponds to an image related chunk.
IsWPI(WebPChunkId id)188 static WEBP_INLINE int IsWPI(WebPChunkId id) {
189 switch (id) {
190 case WEBP_CHUNK_ANMF:
191 case WEBP_CHUNK_ALPHA:
192 case WEBP_CHUNK_IMAGE: return 1;
193 default: return 0;
194 }
195 }
196
197 // Pushes 'wpi' at the end of 'wpi_list'.
198 WebPMuxError MuxImagePush(const WebPMuxImage* wpi, WebPMuxImage** wpi_list);
199
200 // Delete nth image in the image list.
201 WebPMuxError MuxImageDeleteNth(WebPMuxImage** wpi_list, uint32_t nth);
202
203 // Get nth image in the image list.
204 WebPMuxError MuxImageGetNth(const WebPMuxImage** wpi_list, uint32_t nth,
205 WebPMuxImage** wpi);
206
207 // Total size of the given image.
208 size_t MuxImageDiskSize(const WebPMuxImage* const wpi);
209
210 // Write out the given image into 'dst'.
211 uint8_t* MuxImageEmit(const WebPMuxImage* const wpi, uint8_t* dst);
212
213 //------------------------------------------------------------------------------
214 // Helper methods for mux.
215
216 // Checks if the given image list contains at least one image with alpha.
217 int MuxHasAlpha(const WebPMuxImage* images);
218
219 // Write out RIFF header into 'data', given total data size 'size'.
220 uint8_t* MuxEmitRiffHeader(uint8_t* const data, size_t size);
221
222 // Returns the list where chunk with given ID is to be inserted in mux.
223 WebPChunk** MuxGetChunkListFromId(const WebPMux* mux, WebPChunkId id);
224
225 // Validates the given mux object.
226 WebPMuxError MuxValidate(const WebPMux* const mux);
227
228 //------------------------------------------------------------------------------
229
230 #ifdef __cplusplus
231 } // extern "C"
232 #endif
233
234 #endif // WEBP_MUX_MUXI_H_
235