decode.h revision 2a99a7e74a7f215066514fe81d2bfa6639d9eddd
15821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Copyright 2010 Google Inc. All Rights Reserved. 25821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 35821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// This code is licensed under the same terms as WebM: 45821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Software License Agreement: http://www.webmproject.org/license/software/ 55821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Additional IP Rights Grant: http://www.webmproject.org/license/additional/ 65821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// ----------------------------------------------------------------------------- 75821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 85821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Main decoding functions for WebP images. 95821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Author: Skal (pascal.massimino@gmail.com) 115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#ifndef WEBP_WEBP_DECODE_H_ 135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#define WEBP_WEBP_DECODE_H_ 145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "./types.h" 165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#if defined(__cplusplus) || defined(c_plusplus) 185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)extern "C" { 195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#endif 205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 212a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)#define WEBP_DECODER_ABI_VERSION 0x0201 // MAJOR(8b) + MINOR(8b) 222a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 232a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)typedef struct WebPRGBABuffer WebPRGBABuffer; 242a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)typedef struct WebPYUVABuffer WebPYUVABuffer; 252a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)typedef struct WebPDecBuffer WebPDecBuffer; 262a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)#if !(defined(__cplusplus) || defined(c_plusplus)) 272a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)typedef enum VP8StatusCode VP8StatusCode; 282a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)typedef enum WEBP_CSP_MODE WEBP_CSP_MODE; 292a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)#endif 302a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)typedef struct WebPIDecoder WebPIDecoder; 312a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)typedef struct WebPBitstreamFeatures WebPBitstreamFeatures; 322a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)typedef struct WebPDecoderOptions WebPDecoderOptions; 332a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)typedef struct WebPDecoderConfig WebPDecoderConfig; 345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Return the decoder's version number, packed in hexadecimal using 8bits for 365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// each of major/minor/revision. E.g: v2.5.7 is 0x020507. 375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)WEBP_EXTERN(int) WebPGetDecoderVersion(void); 385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Retrieve basic header information: width, height. 405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// This function will also validate the header and return 0 in 415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// case of formatting error. 425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Pointers 'width' and 'height' can be passed NULL if deemed irrelevant. 435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)WEBP_EXTERN(int) WebPGetInfo(const uint8_t* data, size_t data_size, 445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int* width, int* height); 455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Decodes WebP images pointed to by 'data' and returns RGBA samples, along 475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// with the dimensions in *width and *height. The ordering of samples in 485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// memory is R, G, B, A, R, G, B, A... in scan order (endian-independent). 495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// The returned pointer should be deleted calling free(). 505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Returns NULL in case of error. 515821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)WEBP_EXTERN(uint8_t*) WebPDecodeRGBA(const uint8_t* data, size_t data_size, 525821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int* width, int* height); 535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 545821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Same as WebPDecodeRGBA, but returning A, R, G, B, A, R, G, B... ordered data. 555821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)WEBP_EXTERN(uint8_t*) WebPDecodeARGB(const uint8_t* data, size_t data_size, 565821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int* width, int* height); 575821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 585821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Same as WebPDecodeRGBA, but returning B, G, R, A, B, G, R, A... ordered data. 595821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)WEBP_EXTERN(uint8_t*) WebPDecodeBGRA(const uint8_t* data, size_t data_size, 605821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int* width, int* height); 615821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 625821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Same as WebPDecodeRGBA, but returning R, G, B, R, G, B... ordered data. 635821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// If the bitstream contains transparency, it is ignored. 645821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)WEBP_EXTERN(uint8_t*) WebPDecodeRGB(const uint8_t* data, size_t data_size, 655821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int* width, int* height); 665821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 675821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Same as WebPDecodeRGB, but returning B, G, R, B, G, R... ordered data. 685821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)WEBP_EXTERN(uint8_t*) WebPDecodeBGR(const uint8_t* data, size_t data_size, 695821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int* width, int* height); 705821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 715821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 725821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Decode WebP images pointed to by 'data' to Y'UV format(*). The pointer 735821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// returned is the Y samples buffer. Upon return, *u and *v will point to 745821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// the U and V chroma data. These U and V buffers need NOT be free()'d, 755821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// unlike the returned Y luma one. The dimension of the U and V planes 765821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// are both (*width + 1) / 2 and (*height + 1)/ 2. 775821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Upon return, the Y buffer has a stride returned as '*stride', while U and V 785821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// have a common stride returned as '*uv_stride'. 795821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Return NULL in case of error. 805821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// (*) Also named Y'CbCr. See: http://en.wikipedia.org/wiki/YCbCr 815821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)WEBP_EXTERN(uint8_t*) WebPDecodeYUV(const uint8_t* data, size_t data_size, 825821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int* width, int* height, 835821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint8_t** u, uint8_t** v, 845821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int* stride, int* uv_stride); 855821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 865821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// These five functions are variants of the above ones, that decode the image 875821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// directly into a pre-allocated buffer 'output_buffer'. The maximum storage 885821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// available in this buffer is indicated by 'output_buffer_size'. If this 895821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// storage is not sufficient (or an error occurred), NULL is returned. 905821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Otherwise, output_buffer is returned, for convenience. 915821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// The parameter 'output_stride' specifies the distance (in bytes) 925821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// between scanlines. Hence, output_buffer_size is expected to be at least 935821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// output_stride x picture-height. 945821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)WEBP_EXTERN(uint8_t*) WebPDecodeRGBAInto( 955821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const uint8_t* data, size_t data_size, 965821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint8_t* output_buffer, size_t output_buffer_size, int output_stride); 975821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)WEBP_EXTERN(uint8_t*) WebPDecodeARGBInto( 985821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const uint8_t* data, size_t data_size, 995821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint8_t* output_buffer, size_t output_buffer_size, int output_stride); 1005821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)WEBP_EXTERN(uint8_t*) WebPDecodeBGRAInto( 1015821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const uint8_t* data, size_t data_size, 1025821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint8_t* output_buffer, size_t output_buffer_size, int output_stride); 1035821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1045821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// RGB and BGR variants. Here too the transparency information, if present, 1055821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// will be dropped and ignored. 1065821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)WEBP_EXTERN(uint8_t*) WebPDecodeRGBInto( 1075821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const uint8_t* data, size_t data_size, 1085821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint8_t* output_buffer, size_t output_buffer_size, int output_stride); 1095821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)WEBP_EXTERN(uint8_t*) WebPDecodeBGRInto( 1105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const uint8_t* data, size_t data_size, 1115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint8_t* output_buffer, size_t output_buffer_size, int output_stride); 1125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// WebPDecodeYUVInto() is a variant of WebPDecodeYUV() that operates directly 1145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// into pre-allocated luma/chroma plane buffers. This function requires the 1155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// strides to be passed: one for the luma plane and one for each of the 1165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// chroma ones. The size of each plane buffer is passed as 'luma_size', 1175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 'u_size' and 'v_size' respectively. 1185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Pointer to the luma plane ('*luma') is returned or NULL if an error occurred 1195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// during decoding (or because some buffers were found to be too small). 1205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)WEBP_EXTERN(uint8_t*) WebPDecodeYUVInto( 1215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const uint8_t* data, size_t data_size, 1225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint8_t* luma, size_t luma_size, int luma_stride, 1235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint8_t* u, size_t u_size, int u_stride, 1245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint8_t* v, size_t v_size, int v_stride); 1255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)//------------------------------------------------------------------------------ 1275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Output colorspaces and buffer 1285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Colorspaces 1305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Note: the naming describes the byte-ordering of packed samples in memory. 1315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// For instance, MODE_BGRA relates to samples ordered as B,G,R,A,B,G,R,A,... 1325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Non-capital names (e.g.:MODE_Argb) relates to pre-multiplied RGB channels. 1332a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)// RGBA-4444 and RGB-565 colorspaces are represented by following byte-order: 1342a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)// RGBA-4444: [r3 r2 r1 r0 g3 g2 g1 g0], [b3 b2 b1 b0 a3 a2 a1 a0], ... 1352a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)// RGB-565: [r4 r3 r2 r1 r0 g5 g4 g3], [g2 g1 g0 b4 b3 b2 b1 b0], ... 1362a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)// In the case WEBP_SWAP_16BITS_CSP is defined, the bytes are swapped for 1372a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)// these two modes: 1382a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)// RGBA-4444: [b3 b2 b1 b0 a3 a2 a1 a0], [r3 r2 r1 r0 g3 g2 g1 g0], ... 1392a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)// RGB-565: [g2 g1 g0 b4 b3 b2 b1 b0], [r4 r3 r2 r1 r0 g5 g4 g3], ... 1402a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 1412a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)enum WEBP_CSP_MODE { 1422a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) MODE_RGB = 0, MODE_RGBA = 1, 1432a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) MODE_BGR = 2, MODE_BGRA = 3, 1442a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) MODE_ARGB = 4, MODE_RGBA_4444 = 5, 1452a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) MODE_RGB_565 = 6, 1462a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // RGB-premultiplied transparent modes (alpha value is preserved) 1472a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) MODE_rgbA = 7, 1482a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) MODE_bgrA = 8, 1492a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) MODE_Argb = 9, 1502a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) MODE_rgbA_4444 = 10, 1512a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // YUV modes must come after RGB ones. 1522a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) MODE_YUV = 11, MODE_YUVA = 12, // yuv 4:2:0 1532a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) MODE_LAST = 13 1542a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)}; 1555821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1565821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Some useful macros: 1575821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)static WEBP_INLINE int WebPIsPremultipliedMode(WEBP_CSP_MODE mode) { 1585821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return (mode == MODE_rgbA || mode == MODE_bgrA || mode == MODE_Argb || 1595821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) mode == MODE_rgbA_4444); 1605821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 1615821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1625821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)static WEBP_INLINE int WebPIsAlphaMode(WEBP_CSP_MODE mode) { 1635821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return (mode == MODE_RGBA || mode == MODE_BGRA || mode == MODE_ARGB || 1645821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) mode == MODE_RGBA_4444 || mode == MODE_YUVA || 1655821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) WebPIsPremultipliedMode(mode)); 1665821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 1675821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1685821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)static WEBP_INLINE int WebPIsRGBMode(WEBP_CSP_MODE mode) { 1695821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return (mode < MODE_YUV); 1705821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 1715821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1725821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)//------------------------------------------------------------------------------ 1735821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// WebPDecBuffer: Generic structure for describing the output sample buffer. 1745821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1752a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)struct WebPRGBABuffer { // view as RGBA 1765821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint8_t* rgba; // pointer to RGBA samples 1775821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int stride; // stride in bytes from one scanline to the next. 1785821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) size_t size; // total size of the *rgba buffer. 1792a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)}; 1805821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1812a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)struct WebPYUVABuffer { // view as YUVA 1825821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint8_t* y, *u, *v, *a; // pointer to luma, chroma U/V, alpha samples 1835821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int y_stride; // luma stride 1845821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int u_stride, v_stride; // chroma strides 1855821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int a_stride; // alpha stride 1865821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) size_t y_size; // luma plane size 1875821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) size_t u_size, v_size; // chroma planes size 1885821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) size_t a_size; // alpha-plane size 1892a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)}; 1905821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1915821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Output buffer 1922a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)struct WebPDecBuffer { 1935821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) WEBP_CSP_MODE colorspace; // Colorspace. 1945821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int width, height; // Dimensions. 1955821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int is_external_memory; // If true, 'internal_memory' pointer is not used. 1965821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) union { 1975821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) WebPRGBABuffer RGBA; 1985821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) WebPYUVABuffer YUVA; 1995821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } u; // Nameless union of buffer parameters. 2005821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint32_t pad[4]; // padding for later use 2015821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 2025821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint8_t* private_memory; // Internally allocated memory (only when 2035821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // is_external_memory is false). Should not be used 2045821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // externally, but accessed via the buffer union. 2052a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)}; 2065821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 2075821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Internal, version-checked, entry point 2085821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)WEBP_EXTERN(int) WebPInitDecBufferInternal(WebPDecBuffer*, int); 2095821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 2105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Initialize the structure as empty. Must be called before any other use. 2115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Returns false in case of version mismatch 2125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)static WEBP_INLINE int WebPInitDecBuffer(WebPDecBuffer* buffer) { 2135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return WebPInitDecBufferInternal(buffer, WEBP_DECODER_ABI_VERSION); 2145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 2155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 2165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Free any memory associated with the buffer. Must always be called last. 2175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Note: doesn't free the 'buffer' structure itself. 2185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)WEBP_EXTERN(void) WebPFreeDecBuffer(WebPDecBuffer* buffer); 2195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 2205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)//------------------------------------------------------------------------------ 2215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Enumeration of the status codes 2225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 2232a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)enum VP8StatusCode { 2245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) VP8_STATUS_OK = 0, 2255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) VP8_STATUS_OUT_OF_MEMORY, 2265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) VP8_STATUS_INVALID_PARAM, 2275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) VP8_STATUS_BITSTREAM_ERROR, 2285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) VP8_STATUS_UNSUPPORTED_FEATURE, 2295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) VP8_STATUS_SUSPENDED, 2305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) VP8_STATUS_USER_ABORT, 2315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) VP8_STATUS_NOT_ENOUGH_DATA 2322a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)}; 2335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 2345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)//------------------------------------------------------------------------------ 2355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Incremental decoding 2365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 2375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// This API allows streamlined decoding of partial data. 2385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Picture can be incrementally decoded as data become available thanks to the 2395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// WebPIDecoder object. This object can be left in a SUSPENDED state if the 2405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// picture is only partially decoded, pending additional input. 2415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Code example: 2425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 2435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// WebPInitDecBuffer(&buffer); 2445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// buffer.colorspace = mode; 2455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// ... 2465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// WebPIDecoder* idec = WebPINewDecoder(&buffer); 2475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// while (has_more_data) { 2485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// // ... (get additional data) 2495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// status = WebPIAppend(idec, new_data, new_data_size); 2505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// if (status != VP8_STATUS_SUSPENDED || 2515821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// break; 2525821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// } 2535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 2545821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// // The above call decodes the current available buffer. 2555821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// // Part of the image can now be refreshed by calling to 2565821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// // WebPIDecGetRGB()/WebPIDecGetYUVA() etc. 2575821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// } 2585821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// WebPIDelete(idec); 2595821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 2605821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Creates a new incremental decoder with the supplied buffer parameter. 2615821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// This output_buffer can be passed NULL, in which case a default output buffer 2625821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// is used (with MODE_RGB). Otherwise, an internal reference to 'output_buffer' 2635821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// is kept, which means that the lifespan of 'output_buffer' must be larger than 2645821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// that of the returned WebPIDecoder object. 2655821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Returns NULL if the allocation failed. 2665821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)WEBP_EXTERN(WebPIDecoder*) WebPINewDecoder(WebPDecBuffer* output_buffer); 2675821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 2685821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// This function allocates and initializes an incremental-decoder object, which 2695821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// will output the RGB/A samples specified by 'csp' into a preallocated 2705821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// buffer 'output_buffer'. The size of this buffer is at least 2715821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 'output_buffer_size' and the stride (distance in bytes between two scanlines) 2722a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)// is specified by 'output_stride'. 2732a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)// Additionally, output_buffer can be passed NULL in which case the output 2742a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)// buffer will be allocated automatically when the decoding starts. The 2752a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)// colorspace 'csp' is taken into account for allocating this buffer. All other 2762a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)// parameters are ignored. 2772a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)// Returns NULL if the allocation failed, or if some parameters are invalid. 2785821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)WEBP_EXTERN(WebPIDecoder*) WebPINewRGB( 2795821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) WEBP_CSP_MODE csp, 2805821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint8_t* output_buffer, size_t output_buffer_size, int output_stride); 2815821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 2825821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// This function allocates and initializes an incremental-decoder object, which 2832a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)// will output the raw luma/chroma samples into a preallocated planes if 2842a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)// supplied. The luma plane is specified by its pointer 'luma', its size 2852a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)// 'luma_size' and its stride 'luma_stride'. Similarly, the chroma-u plane 2862a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)// is specified by the 'u', 'u_size' and 'u_stride' parameters, and the chroma-v 2872a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)// plane by 'v' and 'v_size'. And same for the alpha-plane. The 'a' pointer 2882a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)// can be pass NULL in case one is not interested in the transparency plane. 2892a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)// Conversely, 'luma' can be passed NULL if no preallocated planes are supplied. 2902a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)// In this case, the output buffer will be automatically allocated (using 2912a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)// MODE_YUVA) when decoding starts. All parameters are then ignored. 2922a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)// Returns NULL if the allocation failed or if a parameter is invalid. 2935821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)WEBP_EXTERN(WebPIDecoder*) WebPINewYUVA( 2945821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint8_t* luma, size_t luma_size, int luma_stride, 2955821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint8_t* u, size_t u_size, int u_stride, 2965821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint8_t* v, size_t v_size, int v_stride, 2975821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint8_t* a, size_t a_size, int a_stride); 2985821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 2995821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Deprecated version of the above, without the alpha plane. 3005821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Kept for backward compatibility. 3015821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)WEBP_EXTERN(WebPIDecoder*) WebPINewYUV( 3025821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint8_t* luma, size_t luma_size, int luma_stride, 3035821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint8_t* u, size_t u_size, int u_stride, 3045821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint8_t* v, size_t v_size, int v_stride); 3055821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 3065821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Deletes the WebPIDecoder object and associated memory. Must always be called 3075821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// if WebPINewDecoder, WebPINewRGB or WebPINewYUV succeeded. 3085821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)WEBP_EXTERN(void) WebPIDelete(WebPIDecoder* idec); 3095821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 3105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Copies and decodes the next available data. Returns VP8_STATUS_OK when 3115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// the image is successfully decoded. Returns VP8_STATUS_SUSPENDED when more 3125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// data is expected. Returns error in other cases. 3135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)WEBP_EXTERN(VP8StatusCode) WebPIAppend( 3145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) WebPIDecoder* idec, const uint8_t* data, size_t data_size); 3155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 3165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// A variant of the above function to be used when data buffer contains 3175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// partial data from the beginning. In this case data buffer is not copied 3185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// to the internal memory. 3195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Note that the value of the 'data' pointer can change between calls to 3205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// WebPIUpdate, for instance when the data buffer is resized to fit larger data. 3215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)WEBP_EXTERN(VP8StatusCode) WebPIUpdate( 3225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) WebPIDecoder* idec, const uint8_t* data, size_t data_size); 3235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 3245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Returns the RGB/A image decoded so far. Returns NULL if output params 3255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// are not initialized yet. The RGB/A output type corresponds to the colorspace 3265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// specified during call to WebPINewDecoder() or WebPINewRGB(). 3275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// *last_y is the index of last decoded row in raster scan order. Some pointers 3285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// (*last_y, *width etc.) can be NULL if corresponding information is not 3295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// needed. 3305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)WEBP_EXTERN(uint8_t*) WebPIDecGetRGB( 3315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const WebPIDecoder* idec, int* last_y, 3325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int* width, int* height, int* stride); 3335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 3345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Same as above function to get a YUVA image. Returns pointer to the luma 3355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// plane or NULL in case of error. If there is no alpha information 3365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// the alpha pointer '*a' will be returned NULL. 3375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)WEBP_EXTERN(uint8_t*) WebPIDecGetYUVA( 3385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const WebPIDecoder* idec, int* last_y, 3395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint8_t** u, uint8_t** v, uint8_t** a, 3405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int* width, int* height, int* stride, int* uv_stride, int* a_stride); 3415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 3425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Deprecated alpha-less version of WebPIDecGetYUVA(): it will ignore the 3435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// alpha information (if present). Kept for backward compatibility. 3445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)static WEBP_INLINE uint8_t* WebPIDecGetYUV( 3455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const WebPIDecoder* idec, int* last_y, uint8_t** u, uint8_t** v, 3465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int* width, int* height, int* stride, int* uv_stride) { 3475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return WebPIDecGetYUVA(idec, last_y, u, v, NULL, width, height, 3485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) stride, uv_stride, NULL); 3495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 3505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 3515821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Generic call to retrieve information about the displayable area. 3525821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// If non NULL, the left/right/width/height pointers are filled with the visible 3535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// rectangular area so far. 3545821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Returns NULL in case the incremental decoder object is in an invalid state. 3555821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Otherwise returns the pointer to the internal representation. This structure 3565821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// is read-only, tied to WebPIDecoder's lifespan and should not be modified. 3575821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)WEBP_EXTERN(const WebPDecBuffer*) WebPIDecodedArea( 3585821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const WebPIDecoder* idec, int* left, int* top, int* width, int* height); 3595821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 3605821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)//------------------------------------------------------------------------------ 3615821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Advanced decoding parametrization 3625821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 3635821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Code sample for using the advanced decoding API 3645821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)/* 3655821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // A) Init a configuration object 3665821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) WebPDecoderConfig config; 3675821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) CHECK(WebPInitDecoderConfig(&config)); 3685821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 3695821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // B) optional: retrieve the bitstream's features. 3705821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) CHECK(WebPGetFeatures(data, data_size, &config.input) == VP8_STATUS_OK); 3715821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 3725821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // C) Adjust 'config', if needed 3732a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) config.no_fancy_upsampling = 1; 3745821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) config.output.colorspace = MODE_BGRA; 3755821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // etc. 3765821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 3775821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Note that you can also make config.output point to an externally 3785821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // supplied memory buffer, provided it's big enough to store the decoded 3795821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // picture. Otherwise, config.output will just be used to allocate memory 3805821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // and store the decoded picture. 3815821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 3825821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // D) Decode! 3835821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) CHECK(WebPDecode(data, data_size, &config) == VP8_STATUS_OK); 3845821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 3855821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // E) Decoded image is now in config.output (and config.output.u.RGBA) 3865821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 3875821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // F) Reclaim memory allocated in config's object. It's safe to call 3885821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // this function even if the memory is external and wasn't allocated 3895821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // by WebPDecode(). 3905821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) WebPFreeDecBuffer(&config.output); 3915821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)*/ 3925821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 3935821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Features gathered from the bitstream 3942a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)struct WebPBitstreamFeatures { 3952a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) int width; // Width in pixels, as read from the bitstream. 3962a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) int height; // Height in pixels, as read from the bitstream. 3972a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) int has_alpha; // True if the bitstream contains an alpha channel. 3982a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) int has_animation; // True if the bitstream is an animation. 3995821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 4005821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Unused for now: 4015821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int bitstream_version; // should be 0 for now. TODO(later) 4025821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int no_incremental_decoding; // if true, using incremental decoding is not 4035821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // recommended. 4045821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int rotate; // TODO(later) 4055821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int uv_sampling; // should be 0 for now. TODO(later) 4062a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) uint32_t pad[2]; // padding for later use 4072a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)}; 4085821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 4095821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Internal, version-checked, entry point 4105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)WEBP_EXTERN(VP8StatusCode) WebPGetFeaturesInternal( 4115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const uint8_t*, size_t, WebPBitstreamFeatures*, int); 4125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 4135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Retrieve features from the bitstream. The *features structure is filled 4145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// with information gathered from the bitstream. 4152a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)// Returns VP8_STATUS_OK when the features are successfully retrieved. Returns 4162a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)// VP8_STATUS_NOT_ENOUGH_DATA when more data is needed to retrieve the 4172a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)// features from headers. Returns error in other cases. 4185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)static WEBP_INLINE VP8StatusCode WebPGetFeatures( 4195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const uint8_t* data, size_t data_size, 4205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) WebPBitstreamFeatures* features) { 4215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return WebPGetFeaturesInternal(data, data_size, features, 4225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) WEBP_DECODER_ABI_VERSION); 4235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 4245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 4255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Decoding options 4262a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)struct WebPDecoderOptions { 4275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int bypass_filtering; // if true, skip the in-loop filtering 4285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int no_fancy_upsampling; // if true, use faster pointwise upsampler 4295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int use_cropping; // if true, cropping is applied _first_ 4305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int crop_left, crop_top; // top-left position for cropping. 4315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Will be snapped to even values. 4325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int crop_width, crop_height; // dimension of the cropping area 4335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int use_scaling; // if true, scaling is applied _afterward_ 4345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int scaled_width, scaled_height; // final resolution 4355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int use_threads; // if true, use multi-threaded decoding 4365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 4375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Unused for now: 4385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int force_rotation; // forced rotation (to be applied _last_) 4395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int no_enhancement; // if true, discard enhancement layer 4405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint32_t pad[6]; // padding for later use 4412a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)}; 4425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 4435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Main object storing the configuration for advanced decoding. 4442a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)struct WebPDecoderConfig { 4455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) WebPBitstreamFeatures input; // Immutable bitstream features (optional) 4465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) WebPDecBuffer output; // Output buffer (can point to external mem) 4475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) WebPDecoderOptions options; // Decoding options 4482a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)}; 4495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 4505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Internal, version-checked, entry point 4515821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)WEBP_EXTERN(int) WebPInitDecoderConfigInternal(WebPDecoderConfig*, int); 4525821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 4535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Initialize the configuration as empty. This function must always be 4545821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// called first, unless WebPGetFeatures() is to be called. 4555821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Returns false in case of mismatched version. 4565821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)static WEBP_INLINE int WebPInitDecoderConfig(WebPDecoderConfig* config) { 4575821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return WebPInitDecoderConfigInternal(config, WEBP_DECODER_ABI_VERSION); 4585821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 4595821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 4605821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Instantiate a new incremental decoder object with the requested 4615821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// configuration. The bitstream can be passed using 'data' and 'data_size' 4625821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// parameter, in which case the features will be parsed and stored into 4635821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// config->input. Otherwise, 'data' can be NULL and no parsing will occur. 4645821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Note that 'config' can be NULL too, in which case a default configuration 4655821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// is used. 4665821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// The return WebPIDecoder object must always be deleted calling WebPIDelete(). 4675821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Returns NULL in case of error (and config->status will then reflect 4685821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// the error condition). 4695821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)WEBP_EXTERN(WebPIDecoder*) WebPIDecode(const uint8_t* data, size_t data_size, 4705821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) WebPDecoderConfig* config); 4715821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 4725821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Non-incremental version. This version decodes the full data at once, taking 4735821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 'config' into account. Returns decoding status (which should be VP8_STATUS_OK 4745821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// if the decoding was successful). 4755821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)WEBP_EXTERN(VP8StatusCode) WebPDecode(const uint8_t* data, size_t data_size, 4765821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) WebPDecoderConfig* config); 4775821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 4785821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#if defined(__cplusplus) || defined(c_plusplus) 4795821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} // extern "C" 4805821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#endif 4815821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 4825821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#endif /* WEBP_WEBP_DECODE_H_ */ 483