1 // Copyright 2011 Google Inc. All Rights Reserved. 2 // 3 // This code is licensed under the same terms as WebM: 4 // Software License Agreement: http://www.webmproject.org/license/software/ 5 // Additional IP Rights Grant: http://www.webmproject.org/license/additional/ 6 // ----------------------------------------------------------------------------- 7 // 8 // WebP encoder: main interface 9 // 10 // Author: Skal (pascal.massimino (at) gmail.com) 11 12 #ifndef WEBP_WEBP_ENCODE_H_ 13 #define WEBP_WEBP_ENCODE_H_ 14 15 #include "./types.h" 16 17 #if defined(__cplusplus) || defined(c_plusplus) 18 extern "C" { 19 #endif 20 21 #define WEBP_ENCODER_ABI_VERSION 0x0201 // MAJOR(8b) + MINOR(8b) 22 23 #if !(defined(__cplusplus) || defined(c_plusplus)) 24 typedef enum WebPImageHint WebPImageHint; 25 typedef enum WebPEncCSP WebPEncCSP; 26 typedef enum WebPPreset WebPPreset; 27 typedef enum WebPEncodingError WebPEncodingError; 28 #endif 29 typedef struct WebPConfig WebPConfig; 30 typedef struct WebPPicture WebPPicture; // main structure for I/O 31 typedef struct WebPAuxStats WebPAuxStats; 32 typedef struct WebPMemoryWriter WebPMemoryWriter; 33 34 // Return the encoder's version number, packed in hexadecimal using 8bits for 35 // each of major/minor/revision. E.g: v2.5.7 is 0x020507. 36 WEBP_EXTERN(int) WebPGetEncoderVersion(void); 37 38 //------------------------------------------------------------------------------ 39 // One-stop-shop call! No questions asked: 40 41 // Returns the size of the compressed data (pointed to by *output), or 0 if 42 // an error occurred. The compressed data must be released by the caller 43 // using the call 'free(*output)'. 44 // These functions compress using the lossy format, and the quality_factor 45 // can go from 0 (smaller output, lower quality) to 100 (best quality, 46 // larger output). 47 WEBP_EXTERN(size_t) WebPEncodeRGB(const uint8_t* rgb, 48 int width, int height, int stride, 49 float quality_factor, uint8_t** output); 50 WEBP_EXTERN(size_t) WebPEncodeBGR(const uint8_t* bgr, 51 int width, int height, int stride, 52 float quality_factor, uint8_t** output); 53 WEBP_EXTERN(size_t) WebPEncodeRGBA(const uint8_t* rgba, 54 int width, int height, int stride, 55 float quality_factor, uint8_t** output); 56 WEBP_EXTERN(size_t) WebPEncodeBGRA(const uint8_t* bgra, 57 int width, int height, int stride, 58 float quality_factor, uint8_t** output); 59 60 // These functions are the equivalent of the above, but compressing in a 61 // lossless manner. Files are usually larger than lossy format, but will 62 // not suffer any compression loss. 63 WEBP_EXTERN(size_t) WebPEncodeLosslessRGB(const uint8_t* rgb, 64 int width, int height, int stride, 65 uint8_t** output); 66 WEBP_EXTERN(size_t) WebPEncodeLosslessBGR(const uint8_t* bgr, 67 int width, int height, int stride, 68 uint8_t** output); 69 WEBP_EXTERN(size_t) WebPEncodeLosslessRGBA(const uint8_t* rgba, 70 int width, int height, int stride, 71 uint8_t** output); 72 WEBP_EXTERN(size_t) WebPEncodeLosslessBGRA(const uint8_t* bgra, 73 int width, int height, int stride, 74 uint8_t** output); 75 76 //------------------------------------------------------------------------------ 77 // Coding parameters 78 79 // Image characteristics hint for the underlying encoder. 80 enum WebPImageHint { 81 WEBP_HINT_DEFAULT = 0, // default preset. 82 WEBP_HINT_PICTURE, // digital picture, like portrait, inner shot 83 WEBP_HINT_PHOTO, // outdoor photograph, with natural lighting 84 WEBP_HINT_GRAPH, // Discrete tone image (graph, map-tile etc). 85 WEBP_HINT_LAST 86 }; 87 88 // Compression parameters. 89 struct WebPConfig { 90 int lossless; // Lossless encoding (0=lossy(default), 1=lossless). 91 float quality; // between 0 (smallest file) and 100 (biggest) 92 int method; // quality/speed trade-off (0=fast, 6=slower-better) 93 94 WebPImageHint image_hint; // Hint for image type (lossless only for now). 95 96 // Parameters related to lossy compression only: 97 int target_size; // if non-zero, set the desired target size in bytes. 98 // Takes precedence over the 'compression' parameter. 99 float target_PSNR; // if non-zero, specifies the minimal distortion to 100 // try to achieve. Takes precedence over target_size. 101 int segments; // maximum number of segments to use, in [1..4] 102 int sns_strength; // Spatial Noise Shaping. 0=off, 100=maximum. 103 int filter_strength; // range: [0 = off .. 100 = strongest] 104 int filter_sharpness; // range: [0 = off .. 7 = least sharp] 105 int filter_type; // filtering type: 0 = simple, 1 = strong (only used 106 // if filter_strength > 0 or autofilter > 0) 107 int autofilter; // Auto adjust filter's strength [0 = off, 1 = on] 108 int alpha_compression; // Algorithm for encoding the alpha plane (0 = none, 109 // 1 = compressed with WebP lossless). Default is 1. 110 int alpha_filtering; // Predictive filtering method for alpha plane. 111 // 0: none, 1: fast, 2: best. Default if 1. 112 int alpha_quality; // Between 0 (smallest size) and 100 (lossless). 113 // Default is 100. 114 int pass; // number of entropy-analysis passes (in [1..10]). 115 116 int show_compressed; // if true, export the compressed picture back. 117 // In-loop filtering is not applied. 118 int preprocessing; // preprocessing filter (0=none, 1=segment-smooth) 119 int partitions; // log2(number of token partitions) in [0..3]. Default 120 // is set to 0 for easier progressive decoding. 121 int partition_limit; // quality degradation allowed to fit the 512k limit 122 // on prediction modes coding (0: no degradation, 123 // 100: maximum possible degradation). 124 int emulate_jpeg_size; // If true, compression parameters will be remapped 125 // to better match the expected output size from 126 // JPEG compression. Generally, the output size will 127 // be similar but the degradation will be lower. 128 int thread_level; // If non-zero, try and use multi-threaded encoding. 129 int low_memory; // If set, reduce memory usage (but increase CPU use). 130 131 uint32_t pad[5]; // padding for later use 132 }; 133 134 // Enumerate some predefined settings for WebPConfig, depending on the type 135 // of source picture. These presets are used when calling WebPConfigPreset(). 136 enum WebPPreset { 137 WEBP_PRESET_DEFAULT = 0, // default preset. 138 WEBP_PRESET_PICTURE, // digital picture, like portrait, inner shot 139 WEBP_PRESET_PHOTO, // outdoor photograph, with natural lighting 140 WEBP_PRESET_DRAWING, // hand or line drawing, with high-contrast details 141 WEBP_PRESET_ICON, // small-sized colorful images 142 WEBP_PRESET_TEXT // text-like 143 }; 144 145 // Internal, version-checked, entry point 146 WEBP_EXTERN(int) WebPConfigInitInternal(WebPConfig*, WebPPreset, float, int); 147 148 // Should always be called, to initialize a fresh WebPConfig structure before 149 // modification. Returns false in case of version mismatch. WebPConfigInit() 150 // must have succeeded before using the 'config' object. 151 // Note that the default values are lossless=0 and quality=75. 152 static WEBP_INLINE int WebPConfigInit(WebPConfig* config) { 153 return WebPConfigInitInternal(config, WEBP_PRESET_DEFAULT, 75.f, 154 WEBP_ENCODER_ABI_VERSION); 155 } 156 157 // This function will initialize the configuration according to a predefined 158 // set of parameters (referred to by 'preset') and a given quality factor. 159 // This function can be called as a replacement to WebPConfigInit(). Will 160 // return false in case of error. 161 static WEBP_INLINE int WebPConfigPreset(WebPConfig* config, 162 WebPPreset preset, float quality) { 163 return WebPConfigInitInternal(config, preset, quality, 164 WEBP_ENCODER_ABI_VERSION); 165 } 166 167 // Returns true if 'config' is non-NULL and all configuration parameters are 168 // within their valid ranges. 169 WEBP_EXTERN(int) WebPValidateConfig(const WebPConfig* config); 170 171 //------------------------------------------------------------------------------ 172 // Input / Output 173 // Structure for storing auxiliary statistics (mostly for lossy encoding). 174 175 struct WebPAuxStats { 176 int coded_size; // final size 177 178 float PSNR[5]; // peak-signal-to-noise ratio for Y/U/V/All/Alpha 179 int block_count[3]; // number of intra4/intra16/skipped macroblocks 180 int header_bytes[2]; // approximate number of bytes spent for header 181 // and mode-partition #0 182 int residual_bytes[3][4]; // approximate number of bytes spent for 183 // DC/AC/uv coefficients for each (0..3) segments. 184 int segment_size[4]; // number of macroblocks in each segments 185 int segment_quant[4]; // quantizer values for each segments 186 int segment_level[4]; // filtering strength for each segments [0..63] 187 188 int alpha_data_size; // size of the transparency data 189 int layer_data_size; // size of the enhancement layer data 190 191 // lossless encoder statistics 192 uint32_t lossless_features; // bit0:predictor bit1:cross-color transform 193 // bit2:subtract-green bit3:color indexing 194 int histogram_bits; // number of precision bits of histogram 195 int transform_bits; // precision bits for transform 196 int cache_bits; // number of bits for color cache lookup 197 int palette_size; // number of color in palette, if used 198 int lossless_size; // final lossless size 199 200 uint32_t pad[4]; // padding for later use 201 }; 202 203 // Signature for output function. Should return true if writing was successful. 204 // data/data_size is the segment of data to write, and 'picture' is for 205 // reference (and so one can make use of picture->custom_ptr). 206 typedef int (*WebPWriterFunction)(const uint8_t* data, size_t data_size, 207 const WebPPicture* picture); 208 209 // WebPMemoryWrite: a special WebPWriterFunction that writes to memory using 210 // the following WebPMemoryWriter object (to be set as a custom_ptr). 211 struct WebPMemoryWriter { 212 uint8_t* mem; // final buffer (of size 'max_size', larger than 'size'). 213 size_t size; // final size 214 size_t max_size; // total capacity 215 uint32_t pad[1]; // padding for later use 216 }; 217 218 // The following must be called first before any use. 219 WEBP_EXTERN(void) WebPMemoryWriterInit(WebPMemoryWriter* writer); 220 221 // The custom writer to be used with WebPMemoryWriter as custom_ptr. Upon 222 // completion, writer.mem and writer.size will hold the coded data. 223 // writer.mem must be freed using the call 'free(writer.mem)'. 224 WEBP_EXTERN(int) WebPMemoryWrite(const uint8_t* data, size_t data_size, 225 const WebPPicture* picture); 226 227 // Progress hook, called from time to time to report progress. It can return 228 // false to request an abort of the encoding process, or true otherwise if 229 // everything is OK. 230 typedef int (*WebPProgressHook)(int percent, const WebPPicture* picture); 231 232 // Color spaces. 233 enum WebPEncCSP { 234 // chroma sampling 235 WEBP_YUV420 = 0, // 4:2:0 236 WEBP_YUV422 = 1, // 4:2:2 237 WEBP_YUV444 = 2, // 4:4:4 238 WEBP_YUV400 = 3, // grayscale 239 WEBP_CSP_UV_MASK = 3, // bit-mask to get the UV sampling factors 240 // alpha channel variants 241 WEBP_YUV420A = 4, 242 WEBP_YUV422A = 5, 243 WEBP_YUV444A = 6, 244 WEBP_YUV400A = 7, // grayscale + alpha 245 WEBP_CSP_ALPHA_BIT = 4 // bit that is set if alpha is present 246 }; 247 248 // Encoding error conditions. 249 enum WebPEncodingError { 250 VP8_ENC_OK = 0, 251 VP8_ENC_ERROR_OUT_OF_MEMORY, // memory error allocating objects 252 VP8_ENC_ERROR_BITSTREAM_OUT_OF_MEMORY, // memory error while flushing bits 253 VP8_ENC_ERROR_NULL_PARAMETER, // a pointer parameter is NULL 254 VP8_ENC_ERROR_INVALID_CONFIGURATION, // configuration is invalid 255 VP8_ENC_ERROR_BAD_DIMENSION, // picture has invalid width/height 256 VP8_ENC_ERROR_PARTITION0_OVERFLOW, // partition is bigger than 512k 257 VP8_ENC_ERROR_PARTITION_OVERFLOW, // partition is bigger than 16M 258 VP8_ENC_ERROR_BAD_WRITE, // error while flushing bytes 259 VP8_ENC_ERROR_FILE_TOO_BIG, // file is bigger than 4G 260 VP8_ENC_ERROR_USER_ABORT, // abort request by user 261 VP8_ENC_ERROR_LAST // list terminator. always last. 262 }; 263 264 // maximum width/height allowed (inclusive), in pixels 265 #define WEBP_MAX_DIMENSION 16383 266 267 // Main exchange structure (input samples, output bytes, statistics) 268 struct WebPPicture { 269 270 // INPUT 271 ////////////// 272 // Main flag for encoder selecting between ARGB or YUV input. 273 // It is recommended to use ARGB input (*argb, argb_stride) for lossless 274 // compression, and YUV input (*y, *u, *v, etc.) for lossy compression 275 // since these are the respective native colorspace for these formats. 276 int use_argb; 277 278 // YUV input (mostly used for input to lossy compression) 279 WebPEncCSP colorspace; // colorspace: should be YUV420 for now (=Y'CbCr). 280 int width, height; // dimensions (less or equal to WEBP_MAX_DIMENSION) 281 uint8_t *y, *u, *v; // pointers to luma/chroma planes. 282 int y_stride, uv_stride; // luma/chroma strides. 283 uint8_t* a; // pointer to the alpha plane 284 int a_stride; // stride of the alpha plane 285 uint32_t pad1[2]; // padding for later use 286 287 // ARGB input (mostly used for input to lossless compression) 288 uint32_t* argb; // Pointer to argb (32 bit) plane. 289 int argb_stride; // This is stride in pixels units, not bytes. 290 uint32_t pad2[3]; // padding for later use 291 292 // OUTPUT 293 /////////////// 294 // Byte-emission hook, to store compressed bytes as they are ready. 295 WebPWriterFunction writer; // can be NULL 296 void* custom_ptr; // can be used by the writer. 297 298 // map for extra information (only for lossy compression mode) 299 int extra_info_type; // 1: intra type, 2: segment, 3: quant 300 // 4: intra-16 prediction mode, 301 // 5: chroma prediction mode, 302 // 6: bit cost, 7: distortion 303 uint8_t* extra_info; // if not NULL, points to an array of size 304 // ((width + 15) / 16) * ((height + 15) / 16) that 305 // will be filled with a macroblock map, depending 306 // on extra_info_type. 307 308 // STATS AND REPORTS 309 /////////////////////////// 310 // Pointer to side statistics (updated only if not NULL) 311 WebPAuxStats* stats; 312 313 // Error code for the latest error encountered during encoding 314 WebPEncodingError error_code; 315 316 // If not NULL, report progress during encoding. 317 WebPProgressHook progress_hook; 318 319 void* user_data; // this field is free to be set to any value and 320 // used during callbacks (like progress-report e.g.). 321 322 uint32_t pad3[3]; // padding for later use 323 324 // Unused for now: original samples (for non-YUV420 modes) 325 uint8_t *u0, *v0; 326 int uv0_stride; 327 328 uint32_t pad4[7]; // padding for later use 329 330 // PRIVATE FIELDS 331 //////////////////// 332 void* memory_; // row chunk of memory for yuva planes 333 void* memory_argb_; // and for argb too. 334 void* pad5[2]; // padding for later use 335 }; 336 337 // Internal, version-checked, entry point 338 WEBP_EXTERN(int) WebPPictureInitInternal(WebPPicture*, int); 339 340 // Should always be called, to initialize the structure. Returns false in case 341 // of version mismatch. WebPPictureInit() must have succeeded before using the 342 // 'picture' object. 343 // Note that, by default, use_argb is false and colorspace is WEBP_YUV420. 344 static WEBP_INLINE int WebPPictureInit(WebPPicture* picture) { 345 return WebPPictureInitInternal(picture, WEBP_ENCODER_ABI_VERSION); 346 } 347 348 //------------------------------------------------------------------------------ 349 // WebPPicture utils 350 351 // Convenience allocation / deallocation based on picture->width/height: 352 // Allocate y/u/v buffers as per colorspace/width/height specification. 353 // Note! This function will free the previous buffer if needed. 354 // Returns false in case of memory error. 355 WEBP_EXTERN(int) WebPPictureAlloc(WebPPicture* picture); 356 357 // Release the memory allocated by WebPPictureAlloc() or WebPPictureImport*(). 358 // Note that this function does _not_ free the memory used by the 'picture' 359 // object itself. 360 // Besides memory (which is reclaimed) all other fields of 'picture' are 361 // preserved. 362 WEBP_EXTERN(void) WebPPictureFree(WebPPicture* picture); 363 364 // Copy the pixels of *src into *dst, using WebPPictureAlloc. Upon return, 365 // *dst will fully own the copied pixels (this is not a view). 366 // Returns false in case of memory allocation error. 367 WEBP_EXTERN(int) WebPPictureCopy(const WebPPicture* src, WebPPicture* dst); 368 369 // Compute PSNR, SSIM or LSIM distortion metric between two pictures. 370 // Result is in dB, stores in result[] in the Y/U/V/Alpha/All order. 371 // Returns false in case of error (src and ref don't have same dimension, ...) 372 // Warning: this function is rather CPU-intensive. 373 WEBP_EXTERN(int) WebPPictureDistortion( 374 const WebPPicture* src, const WebPPicture* ref, 375 int metric_type, // 0 = PSNR, 1 = SSIM, 2 = LSIM 376 float result[5]); 377 378 // self-crops a picture to the rectangle defined by top/left/width/height. 379 // Returns false in case of memory allocation error, or if the rectangle is 380 // outside of the source picture. 381 // The rectangle for the view is defined by the top-left corner pixel 382 // coordinates (left, top) as well as its width and height. This rectangle 383 // must be fully be comprised inside the 'src' source picture. If the source 384 // picture uses the YUV420 colorspace, the top and left coordinates will be 385 // snapped to even values. 386 WEBP_EXTERN(int) WebPPictureCrop(WebPPicture* picture, 387 int left, int top, int width, int height); 388 389 // Extracts a view from 'src' picture into 'dst'. The rectangle for the view 390 // is defined by the top-left corner pixel coordinates (left, top) as well 391 // as its width and height. This rectangle must be fully be comprised inside 392 // the 'src' source picture. If the source picture uses the YUV420 colorspace, 393 // the top and left coordinates will be snapped to even values. 394 // Picture 'src' must out-live 'dst' picture. Self-extraction of view is allowed 395 // ('src' equal to 'dst') as a mean of fast-cropping (but note that doing so, 396 // the original dimension will be lost). 397 // Returns false in case of memory allocation error or invalid parameters. 398 WEBP_EXTERN(int) WebPPictureView(const WebPPicture* src, 399 int left, int top, int width, int height, 400 WebPPicture* dst); 401 402 // Returns true if the 'picture' is actually a view and therefore does 403 // not own the memory for pixels. 404 WEBP_EXTERN(int) WebPPictureIsView(const WebPPicture* picture); 405 406 // Rescale a picture to new dimension width x height. 407 // Now gamma correction is applied. 408 // Returns false in case of error (invalid parameter or insufficient memory). 409 WEBP_EXTERN(int) WebPPictureRescale(WebPPicture* pic, int width, int height); 410 411 // Colorspace conversion function to import RGB samples. 412 // Previous buffer will be free'd, if any. 413 // *rgb buffer should have a size of at least height * rgb_stride. 414 // Returns false in case of memory error. 415 WEBP_EXTERN(int) WebPPictureImportRGB( 416 WebPPicture* picture, const uint8_t* rgb, int rgb_stride); 417 // Same, but for RGBA buffer. 418 WEBP_EXTERN(int) WebPPictureImportRGBA( 419 WebPPicture* picture, const uint8_t* rgba, int rgba_stride); 420 // Same, but for RGBA buffer. Imports the RGB direct from the 32-bit format 421 // input buffer ignoring the alpha channel. Avoids needing to copy the data 422 // to a temporary 24-bit RGB buffer to import the RGB only. 423 WEBP_EXTERN(int) WebPPictureImportRGBX( 424 WebPPicture* picture, const uint8_t* rgbx, int rgbx_stride); 425 426 // Variants of the above, but taking BGR(A|X) input. 427 WEBP_EXTERN(int) WebPPictureImportBGR( 428 WebPPicture* picture, const uint8_t* bgr, int bgr_stride); 429 WEBP_EXTERN(int) WebPPictureImportBGRA( 430 WebPPicture* picture, const uint8_t* bgra, int bgra_stride); 431 WEBP_EXTERN(int) WebPPictureImportBGRX( 432 WebPPicture* picture, const uint8_t* bgrx, int bgrx_stride); 433 434 // Converts picture->argb data to the YUVA format specified by 'colorspace'. 435 // Upon return, picture->use_argb is set to false. The presence of real 436 // non-opaque transparent values is detected, and 'colorspace' will be 437 // adjusted accordingly. Note that this method is lossy. 438 // Returns false in case of error. 439 WEBP_EXTERN(int) WebPPictureARGBToYUVA(WebPPicture* picture, 440 WebPEncCSP colorspace); 441 442 // Converts picture->yuv to picture->argb and sets picture->use_argb to true. 443 // The input format must be YUV_420 or YUV_420A. 444 // Note that the use of this method is discouraged if one has access to the 445 // raw ARGB samples, since using YUV420 is comparatively lossy. Also, the 446 // conversion from YUV420 to ARGB incurs a small loss too. 447 // Returns false in case of error. 448 WEBP_EXTERN(int) WebPPictureYUVAToARGB(WebPPicture* picture); 449 450 // Helper function: given a width x height plane of YUV(A) samples 451 // (with stride 'stride'), clean-up the YUV samples under fully transparent 452 // area, to help compressibility (no guarantee, though). 453 WEBP_EXTERN(void) WebPCleanupTransparentArea(WebPPicture* picture); 454 455 // Scan the picture 'picture' for the presence of non fully opaque alpha values. 456 // Returns true in such case. Otherwise returns false (indicating that the 457 // alpha plane can be ignored altogether e.g.). 458 WEBP_EXTERN(int) WebPPictureHasTransparency(const WebPPicture* picture); 459 460 //------------------------------------------------------------------------------ 461 // Main call 462 463 // Main encoding call, after config and picture have been initialized. 464 // 'picture' must be less than 16384x16384 in dimension (cf WEBP_MAX_DIMENSION), 465 // and the 'config' object must be a valid one. 466 // Returns false in case of error, true otherwise. 467 // In case of error, picture->error_code is updated accordingly. 468 // 'picture' can hold the source samples in both YUV(A) or ARGB input, depending 469 // on the value of 'picture->use_argb'. It is highly recommended to use 470 // the former for lossy encoding, and the latter for lossless encoding 471 // (when config.lossless is true). Automatic conversion from one format to 472 // another is provided but they both incur some loss. 473 WEBP_EXTERN(int) WebPEncode(const WebPConfig* config, WebPPicture* picture); 474 475 //------------------------------------------------------------------------------ 476 477 #if defined(__cplusplus) || defined(c_plusplus) 478 } // extern "C" 479 #endif 480 481 #endif /* WEBP_WEBP_ENCODE_H_ */ 482
