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Diffstat (limited to 'media/libwebp/src/webp/encode.h')
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diff --git a/media/libwebp/src/webp/encode.h b/media/libwebp/src/webp/encode.h new file mode 100644 index 0000000000..655166e7d4 --- /dev/null +++ b/media/libwebp/src/webp/encode.h @@ -0,0 +1,546 @@ +// 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. +// ----------------------------------------------------------------------------- +// +// WebP encoder: main interface +// +// Author: Skal (pascal.massimino@gmail.com) + +#ifndef WEBP_WEBP_ENCODE_H_ +#define WEBP_WEBP_ENCODE_H_ + +#include "./types.h" + +#ifdef __cplusplus +extern "C" { +#endif + +#define WEBP_ENCODER_ABI_VERSION 0x020f // MAJOR(8b) + MINOR(8b) + +// Note: forward declaring enumerations is not allowed in (strict) C and C++, +// the types are left here for reference. +// typedef enum WebPImageHint WebPImageHint; +// typedef enum WebPEncCSP WebPEncCSP; +// typedef enum WebPPreset WebPPreset; +// typedef enum WebPEncodingError WebPEncodingError; +typedef struct WebPConfig WebPConfig; +typedef struct WebPPicture WebPPicture; // main structure for I/O +typedef struct WebPAuxStats WebPAuxStats; +typedef struct WebPMemoryWriter WebPMemoryWriter; + +// Return the encoder's version number, packed in hexadecimal using 8bits for +// each of major/minor/revision. E.g: v2.5.7 is 0x020507. +WEBP_EXTERN int WebPGetEncoderVersion(void); + +//------------------------------------------------------------------------------ +// One-stop-shop call! No questions asked: + +// Returns the size of the compressed data (pointed to by *output), or 0 if +// an error occurred. The compressed data must be released by the caller +// using the call 'WebPFree(*output)'. +// These functions compress using the lossy format, and the quality_factor +// can go from 0 (smaller output, lower quality) to 100 (best quality, +// larger output). +WEBP_EXTERN size_t WebPEncodeRGB(const uint8_t* rgb, + int width, int height, int stride, + float quality_factor, uint8_t** output); +WEBP_EXTERN size_t WebPEncodeBGR(const uint8_t* bgr, + int width, int height, int stride, + float quality_factor, uint8_t** output); +WEBP_EXTERN size_t WebPEncodeRGBA(const uint8_t* rgba, + int width, int height, int stride, + float quality_factor, uint8_t** output); +WEBP_EXTERN size_t WebPEncodeBGRA(const uint8_t* bgra, + int width, int height, int stride, + float quality_factor, uint8_t** output); + +// These functions are the equivalent of the above, but compressing in a +// lossless manner. Files are usually larger than lossy format, but will +// not suffer any compression loss. +// Note these functions, like the lossy versions, use the library's default +// settings. For lossless this means 'exact' is disabled. RGB values in +// transparent areas will be modified to improve compression. To avoid this, +// use WebPEncode() and set WebPConfig::exact to 1. +WEBP_EXTERN size_t WebPEncodeLosslessRGB(const uint8_t* rgb, + int width, int height, int stride, + uint8_t** output); +WEBP_EXTERN size_t WebPEncodeLosslessBGR(const uint8_t* bgr, + int width, int height, int stride, + uint8_t** output); +WEBP_EXTERN size_t WebPEncodeLosslessRGBA(const uint8_t* rgba, + int width, int height, int stride, + uint8_t** output); +WEBP_EXTERN size_t WebPEncodeLosslessBGRA(const uint8_t* bgra, + int width, int height, int stride, + uint8_t** output); + +//------------------------------------------------------------------------------ +// Coding parameters + +// Image characteristics hint for the underlying encoder. +typedef enum WebPImageHint { + WEBP_HINT_DEFAULT = 0, // default preset. + WEBP_HINT_PICTURE, // digital picture, like portrait, inner shot + WEBP_HINT_PHOTO, // outdoor photograph, with natural lighting + WEBP_HINT_GRAPH, // Discrete tone image (graph, map-tile etc). + WEBP_HINT_LAST +} WebPImageHint; + +// Compression parameters. +struct WebPConfig { + int lossless; // Lossless encoding (0=lossy(default), 1=lossless). + float quality; // between 0 and 100. For lossy, 0 gives the smallest + // size and 100 the largest. For lossless, this + // parameter is the amount of effort put into the + // compression: 0 is the fastest but gives larger + // files compared to the slowest, but best, 100. + int method; // quality/speed trade-off (0=fast, 6=slower-better) + + WebPImageHint image_hint; // Hint for image type (lossless only for now). + + int target_size; // if non-zero, set the desired target size in bytes. + // Takes precedence over the 'compression' parameter. + float target_PSNR; // if non-zero, specifies the minimal distortion to + // try to achieve. Takes precedence over target_size. + int segments; // maximum number of segments to use, in [1..4] + int sns_strength; // Spatial Noise Shaping. 0=off, 100=maximum. + int filter_strength; // range: [0 = off .. 100 = strongest] + int filter_sharpness; // range: [0 = off .. 7 = least sharp] + int filter_type; // filtering type: 0 = simple, 1 = strong (only used + // if filter_strength > 0 or autofilter > 0) + int autofilter; // Auto adjust filter's strength [0 = off, 1 = on] + int alpha_compression; // Algorithm for encoding the alpha plane (0 = none, + // 1 = compressed with WebP lossless). Default is 1. + int alpha_filtering; // Predictive filtering method for alpha plane. + // 0: none, 1: fast, 2: best. Default if 1. + int alpha_quality; // Between 0 (smallest size) and 100 (lossless). + // Default is 100. + int pass; // number of entropy-analysis passes (in [1..10]). + + int show_compressed; // if true, export the compressed picture back. + // In-loop filtering is not applied. + int preprocessing; // preprocessing filter: + // 0=none, 1=segment-smooth, 2=pseudo-random dithering + int partitions; // log2(number of token partitions) in [0..3]. Default + // is set to 0 for easier progressive decoding. + int partition_limit; // quality degradation allowed to fit the 512k limit + // on prediction modes coding (0: no degradation, + // 100: maximum possible degradation). + int emulate_jpeg_size; // If true, compression parameters will be remapped + // to better match the expected output size from + // JPEG compression. Generally, the output size will + // be similar but the degradation will be lower. + int thread_level; // If non-zero, try and use multi-threaded encoding. + int low_memory; // If set, reduce memory usage (but increase CPU use). + + int near_lossless; // Near lossless encoding [0 = max loss .. 100 = off + // (default)]. + int exact; // if non-zero, preserve the exact RGB values under + // transparent area. Otherwise, discard this invisible + // RGB information for better compression. The default + // value is 0. + + int use_delta_palette; // reserved for future lossless feature + int use_sharp_yuv; // if needed, use sharp (and slow) RGB->YUV conversion + + uint32_t pad[2]; // padding for later use +}; + +// Enumerate some predefined settings for WebPConfig, depending on the type +// of source picture. These presets are used when calling WebPConfigPreset(). +typedef enum WebPPreset { + WEBP_PRESET_DEFAULT = 0, // default preset. + WEBP_PRESET_PICTURE, // digital picture, like portrait, inner shot + WEBP_PRESET_PHOTO, // outdoor photograph, with natural lighting + WEBP_PRESET_DRAWING, // hand or line drawing, with high-contrast details + WEBP_PRESET_ICON, // small-sized colorful images + WEBP_PRESET_TEXT // text-like +} WebPPreset; + +// Internal, version-checked, entry point +WEBP_EXTERN int WebPConfigInitInternal(WebPConfig*, WebPPreset, float, int); + +// Should always be called, to initialize a fresh WebPConfig structure before +// modification. Returns false in case of version mismatch. WebPConfigInit() +// must have succeeded before using the 'config' object. +// Note that the default values are lossless=0 and quality=75. +static WEBP_INLINE int WebPConfigInit(WebPConfig* config) { + return WebPConfigInitInternal(config, WEBP_PRESET_DEFAULT, 75.f, + WEBP_ENCODER_ABI_VERSION); +} + +// This function will initialize the configuration according to a predefined +// set of parameters (referred to by 'preset') and a given quality factor. +// This function can be called as a replacement to WebPConfigInit(). Will +// return false in case of error. +static WEBP_INLINE int WebPConfigPreset(WebPConfig* config, + WebPPreset preset, float quality) { + return WebPConfigInitInternal(config, preset, quality, + WEBP_ENCODER_ABI_VERSION); +} + +// Activate the lossless compression mode with the desired efficiency level +// between 0 (fastest, lowest compression) and 9 (slower, best compression). +// A good default level is '6', providing a fair tradeoff between compression +// speed and final compressed size. +// This function will overwrite several fields from config: 'method', 'quality' +// and 'lossless'. Returns false in case of parameter error. +WEBP_EXTERN int WebPConfigLosslessPreset(WebPConfig* config, int level); + +// Returns true if 'config' is non-NULL and all configuration parameters are +// within their valid ranges. +WEBP_EXTERN int WebPValidateConfig(const WebPConfig* config); + +//------------------------------------------------------------------------------ +// Input / Output +// Structure for storing auxiliary statistics. + +struct WebPAuxStats { + int coded_size; // final size + + float PSNR[5]; // peak-signal-to-noise ratio for Y/U/V/All/Alpha + int block_count[3]; // number of intra4/intra16/skipped macroblocks + int header_bytes[2]; // approximate number of bytes spent for header + // and mode-partition #0 + int residual_bytes[3][4]; // approximate number of bytes spent for + // DC/AC/uv coefficients for each (0..3) segments. + int segment_size[4]; // number of macroblocks in each segments + int segment_quant[4]; // quantizer values for each segments + int segment_level[4]; // filtering strength for each segments [0..63] + + int alpha_data_size; // size of the transparency data + int layer_data_size; // size of the enhancement layer data + + // lossless encoder statistics + uint32_t lossless_features; // bit0:predictor bit1:cross-color transform + // bit2:subtract-green bit3:color indexing + int histogram_bits; // number of precision bits of histogram + int transform_bits; // precision bits for transform + int cache_bits; // number of bits for color cache lookup + int palette_size; // number of color in palette, if used + int lossless_size; // final lossless size + int lossless_hdr_size; // lossless header (transform, huffman etc) size + int lossless_data_size; // lossless image data size + + uint32_t pad[2]; // padding for later use +}; + +// Signature for output function. Should return true if writing was successful. +// data/data_size is the segment of data to write, and 'picture' is for +// reference (and so one can make use of picture->custom_ptr). +typedef int (*WebPWriterFunction)(const uint8_t* data, size_t data_size, + const WebPPicture* picture); + +// WebPMemoryWrite: a special WebPWriterFunction that writes to memory using +// the following WebPMemoryWriter object (to be set as a custom_ptr). +struct WebPMemoryWriter { + uint8_t* mem; // final buffer (of size 'max_size', larger than 'size'). + size_t size; // final size + size_t max_size; // total capacity + uint32_t pad[1]; // padding for later use +}; + +// The following must be called first before any use. +WEBP_EXTERN void WebPMemoryWriterInit(WebPMemoryWriter* writer); + +// The following must be called to deallocate writer->mem memory. The 'writer' +// object itself is not deallocated. +WEBP_EXTERN void WebPMemoryWriterClear(WebPMemoryWriter* writer); +// The custom writer to be used with WebPMemoryWriter as custom_ptr. Upon +// completion, writer.mem and writer.size will hold the coded data. +// writer.mem must be freed by calling WebPMemoryWriterClear. +WEBP_EXTERN int WebPMemoryWrite(const uint8_t* data, size_t data_size, + const WebPPicture* picture); + +// Progress hook, called from time to time to report progress. It can return +// false to request an abort of the encoding process, or true otherwise if +// everything is OK. +typedef int (*WebPProgressHook)(int percent, const WebPPicture* picture); + +// Color spaces. +typedef enum WebPEncCSP { + // chroma sampling + WEBP_YUV420 = 0, // 4:2:0 + WEBP_YUV420A = 4, // alpha channel variant + WEBP_CSP_UV_MASK = 3, // bit-mask to get the UV sampling factors + WEBP_CSP_ALPHA_BIT = 4 // bit that is set if alpha is present +} WebPEncCSP; + +// Encoding error conditions. +typedef enum WebPEncodingError { + VP8_ENC_OK = 0, + VP8_ENC_ERROR_OUT_OF_MEMORY, // memory error allocating objects + VP8_ENC_ERROR_BITSTREAM_OUT_OF_MEMORY, // memory error while flushing bits + VP8_ENC_ERROR_NULL_PARAMETER, // a pointer parameter is NULL + VP8_ENC_ERROR_INVALID_CONFIGURATION, // configuration is invalid + VP8_ENC_ERROR_BAD_DIMENSION, // picture has invalid width/height + VP8_ENC_ERROR_PARTITION0_OVERFLOW, // partition is bigger than 512k + VP8_ENC_ERROR_PARTITION_OVERFLOW, // partition is bigger than 16M + VP8_ENC_ERROR_BAD_WRITE, // error while flushing bytes + VP8_ENC_ERROR_FILE_TOO_BIG, // file is bigger than 4G + VP8_ENC_ERROR_USER_ABORT, // abort request by user + VP8_ENC_ERROR_LAST // list terminator. always last. +} WebPEncodingError; + +// maximum width/height allowed (inclusive), in pixels +#define WEBP_MAX_DIMENSION 16383 + +// Main exchange structure (input samples, output bytes, statistics) +struct WebPPicture { + // INPUT + ////////////// + // Main flag for encoder selecting between ARGB or YUV input. + // It is recommended to use ARGB input (*argb, argb_stride) for lossless + // compression, and YUV input (*y, *u, *v, etc.) for lossy compression + // since these are the respective native colorspace for these formats. + int use_argb; + + // YUV input (mostly used for input to lossy compression) + WebPEncCSP colorspace; // colorspace: should be YUV420 for now (=Y'CbCr). + int width, height; // dimensions (less or equal to WEBP_MAX_DIMENSION) + uint8_t* y, *u, *v; // pointers to luma/chroma planes. + int y_stride, uv_stride; // luma/chroma strides. + uint8_t* a; // pointer to the alpha plane + int a_stride; // stride of the alpha plane + uint32_t pad1[2]; // padding for later use + + // ARGB input (mostly used for input to lossless compression) + uint32_t* argb; // Pointer to argb (32 bit) plane. + int argb_stride; // This is stride in pixels units, not bytes. + uint32_t pad2[3]; // padding for later use + + // OUTPUT + /////////////// + // Byte-emission hook, to store compressed bytes as they are ready. + WebPWriterFunction writer; // can be NULL + void* custom_ptr; // can be used by the writer. + + // map for extra information (only for lossy compression mode) + int extra_info_type; // 1: intra type, 2: segment, 3: quant + // 4: intra-16 prediction mode, + // 5: chroma prediction mode, + // 6: bit cost, 7: distortion + uint8_t* extra_info; // if not NULL, points to an array of size + // ((width + 15) / 16) * ((height + 15) / 16) that + // will be filled with a macroblock map, depending + // on extra_info_type. + + // STATS AND REPORTS + /////////////////////////// + // Pointer to side statistics (updated only if not NULL) + WebPAuxStats* stats; + + // Error code for the latest error encountered during encoding + WebPEncodingError error_code; + + // If not NULL, report progress during encoding. + WebPProgressHook progress_hook; + + void* user_data; // this field is free to be set to any value and + // used during callbacks (like progress-report e.g.). + + uint32_t pad3[3]; // padding for later use + + // Unused for now + uint8_t* pad4, *pad5; + uint32_t pad6[8]; // padding for later use + + // PRIVATE FIELDS + //////////////////// + void* memory_; // row chunk of memory for yuva planes + void* memory_argb_; // and for argb too. + void* pad7[2]; // padding for later use +}; + +// Internal, version-checked, entry point +WEBP_EXTERN int WebPPictureInitInternal(WebPPicture*, int); + +// Should always be called, to initialize the structure. Returns false in case +// of version mismatch. WebPPictureInit() must have succeeded before using the +// 'picture' object. +// Note that, by default, use_argb is false and colorspace is WEBP_YUV420. +static WEBP_INLINE int WebPPictureInit(WebPPicture* picture) { + return WebPPictureInitInternal(picture, WEBP_ENCODER_ABI_VERSION); +} + +//------------------------------------------------------------------------------ +// WebPPicture utils + +// Convenience allocation / deallocation based on picture->width/height: +// Allocate y/u/v buffers as per colorspace/width/height specification. +// Note! This function will free the previous buffer if needed. +// Returns false in case of memory error. +WEBP_EXTERN int WebPPictureAlloc(WebPPicture* picture); + +// Release the memory allocated by WebPPictureAlloc() or WebPPictureImport*(). +// Note that this function does _not_ free the memory used by the 'picture' +// object itself. +// Besides memory (which is reclaimed) all other fields of 'picture' are +// preserved. +WEBP_EXTERN void WebPPictureFree(WebPPicture* picture); + +// Copy the pixels of *src into *dst, using WebPPictureAlloc. Upon return, *dst +// will fully own the copied pixels (this is not a view). The 'dst' picture need +// not be initialized as its content is overwritten. +// Returns false in case of memory allocation error. +WEBP_EXTERN int WebPPictureCopy(const WebPPicture* src, WebPPicture* dst); + +// Compute the single distortion for packed planes of samples. +// 'src' will be compared to 'ref', and the raw distortion stored into +// '*distortion'. The refined metric (log(MSE), log(1 - ssim),...' will be +// stored in '*result'. +// 'x_step' is the horizontal stride (in bytes) between samples. +// 'src/ref_stride' is the byte distance between rows. +// Returns false in case of error (bad parameter, memory allocation error, ...). +WEBP_EXTERN int WebPPlaneDistortion(const uint8_t* src, size_t src_stride, + const uint8_t* ref, size_t ref_stride, + int width, int height, + size_t x_step, + int type, // 0 = PSNR, 1 = SSIM, 2 = LSIM + float* distortion, float* result); + +// Compute PSNR, SSIM or LSIM distortion metric between two pictures. Results +// are in dB, stored in result[] in the B/G/R/A/All order. The distortion is +// always performed using ARGB samples. Hence if the input is YUV(A), the +// picture will be internally converted to ARGB (just for the measurement). +// Warning: this function is rather CPU-intensive. +WEBP_EXTERN int WebPPictureDistortion( + const WebPPicture* src, const WebPPicture* ref, + int metric_type, // 0 = PSNR, 1 = SSIM, 2 = LSIM + float result[5]); + +// self-crops a picture to the rectangle defined by top/left/width/height. +// Returns false in case of memory allocation error, or if the rectangle is +// outside of the source picture. +// The rectangle for the view is defined by the top-left corner pixel +// coordinates (left, top) as well as its width and height. This rectangle +// must be fully be comprised inside the 'src' source picture. If the source +// picture uses the YUV420 colorspace, the top and left coordinates will be +// snapped to even values. +WEBP_EXTERN int WebPPictureCrop(WebPPicture* picture, + int left, int top, int width, int height); + +// Extracts a view from 'src' picture into 'dst'. The rectangle for the view +// is defined by the top-left corner pixel coordinates (left, top) as well +// as its width and height. This rectangle must be fully be comprised inside +// the 'src' source picture. If the source picture uses the YUV420 colorspace, +// the top and left coordinates will be snapped to even values. +// Picture 'src' must out-live 'dst' picture. Self-extraction of view is allowed +// ('src' equal to 'dst') as a mean of fast-cropping (but note that doing so, +// the original dimension will be lost). Picture 'dst' need not be initialized +// with WebPPictureInit() if it is different from 'src', since its content will +// be overwritten. +// Returns false in case of memory allocation error or invalid parameters. +WEBP_EXTERN int WebPPictureView(const WebPPicture* src, + int left, int top, int width, int height, + WebPPicture* dst); + +// Returns true if the 'picture' is actually a view and therefore does +// not own the memory for pixels. +WEBP_EXTERN int WebPPictureIsView(const WebPPicture* picture); + +// Rescale a picture to new dimension width x height. +// If either 'width' or 'height' (but not both) is 0 the corresponding +// dimension will be calculated preserving the aspect ratio. +// No gamma correction is applied. +// Returns false in case of error (invalid parameter or insufficient memory). +WEBP_EXTERN int WebPPictureRescale(WebPPicture* pic, int width, int height); + +// Colorspace conversion function to import RGB samples. +// Previous buffer will be free'd, if any. +// *rgb buffer should have a size of at least height * rgb_stride. +// Returns false in case of memory error. +WEBP_EXTERN int WebPPictureImportRGB( + WebPPicture* picture, const uint8_t* rgb, int rgb_stride); +// Same, but for RGBA buffer. +WEBP_EXTERN int WebPPictureImportRGBA( + WebPPicture* picture, const uint8_t* rgba, int rgba_stride); +// Same, but for RGBA buffer. Imports the RGB direct from the 32-bit format +// input buffer ignoring the alpha channel. Avoids needing to copy the data +// to a temporary 24-bit RGB buffer to import the RGB only. +WEBP_EXTERN int WebPPictureImportRGBX( + WebPPicture* picture, const uint8_t* rgbx, int rgbx_stride); + +// Variants of the above, but taking BGR(A|X) input. +WEBP_EXTERN int WebPPictureImportBGR( + WebPPicture* picture, const uint8_t* bgr, int bgr_stride); +WEBP_EXTERN int WebPPictureImportBGRA( + WebPPicture* picture, const uint8_t* bgra, int bgra_stride); +WEBP_EXTERN int WebPPictureImportBGRX( + WebPPicture* picture, const uint8_t* bgrx, int bgrx_stride); + +// Converts picture->argb data to the YUV420A format. The 'colorspace' +// parameter is deprecated and should be equal to WEBP_YUV420. +// Upon return, picture->use_argb is set to false. The presence of real +// non-opaque transparent values is detected, and 'colorspace' will be +// adjusted accordingly. Note that this method is lossy. +// Returns false in case of error. +WEBP_EXTERN int WebPPictureARGBToYUVA(WebPPicture* picture, + WebPEncCSP /*colorspace = WEBP_YUV420*/); + +// Same as WebPPictureARGBToYUVA(), but the conversion is done using +// pseudo-random dithering with a strength 'dithering' between +// 0.0 (no dithering) and 1.0 (maximum dithering). This is useful +// for photographic picture. +WEBP_EXTERN int WebPPictureARGBToYUVADithered( + WebPPicture* picture, WebPEncCSP colorspace, float dithering); + +// Performs 'sharp' RGBA->YUVA420 downsampling and colorspace conversion. +// Downsampling is handled with extra care in case of color clipping. This +// method is roughly 2x slower than WebPPictureARGBToYUVA() but produces better +// and sharper YUV representation. +// Returns false in case of error. +WEBP_EXTERN int WebPPictureSharpARGBToYUVA(WebPPicture* picture); +// kept for backward compatibility: +WEBP_EXTERN int WebPPictureSmartARGBToYUVA(WebPPicture* picture); + +// Converts picture->yuv to picture->argb and sets picture->use_argb to true. +// The input format must be YUV_420 or YUV_420A. The conversion from YUV420 to +// ARGB incurs a small loss too. +// Note that the use of this colorspace is discouraged if one has access to the +// raw ARGB samples, since using YUV420 is comparatively lossy. +// Returns false in case of error. +WEBP_EXTERN int WebPPictureYUVAToARGB(WebPPicture* picture); + +// Helper function: given a width x height plane of RGBA or YUV(A) samples +// clean-up or smoothen the YUV or RGB samples under fully transparent area, +// to help compressibility (no guarantee, though). +WEBP_EXTERN void WebPCleanupTransparentArea(WebPPicture* picture); + +// Scan the picture 'picture' for the presence of non fully opaque alpha values. +// Returns true in such case. Otherwise returns false (indicating that the +// alpha plane can be ignored altogether e.g.). +WEBP_EXTERN int WebPPictureHasTransparency(const WebPPicture* picture); + +// Remove the transparency information (if present) by blending the color with +// the background color 'background_rgb' (specified as 24bit RGB triplet). +// After this call, all alpha values are reset to 0xff. +WEBP_EXTERN void WebPBlendAlpha(WebPPicture* pic, uint32_t background_rgb); + +//------------------------------------------------------------------------------ +// Main call + +// Main encoding call, after config and picture have been initialized. +// 'picture' must be less than 16384x16384 in dimension (cf WEBP_MAX_DIMENSION), +// and the 'config' object must be a valid one. +// Returns false in case of error, true otherwise. +// In case of error, picture->error_code is updated accordingly. +// 'picture' can hold the source samples in both YUV(A) or ARGB input, depending +// on the value of 'picture->use_argb'. It is highly recommended to use +// the former for lossy encoding, and the latter for lossless encoding +// (when config.lossless is true). Automatic conversion from one format to +// another is provided but they both incur some loss. +WEBP_EXTERN int WebPEncode(const WebPConfig* config, WebPPicture* picture); + +//------------------------------------------------------------------------------ + +#ifdef __cplusplus +} // extern "C" +#endif + +#endif // WEBP_WEBP_ENCODE_H_ |