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prepare experimentation with yuv444 / 422

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+ add a simple rescaling function: WebPPictureRescale() for encoding
+ clean-up the memory managment around the alpha plane
+ fix some includes path by using "../webp/xxx.h" instead of "webp/xxx.h"

New flags for 'cwebp':
 -resize <width> <height>
 -444  (no effect)
 -422  (no effect)
 -400

Change-Id: I25a95f901493f939c2dd789e658493b83bd1abfa
This commit is contained in:
Pascal Massimino
2011-05-02 17:19:00 -07:00
parent 79cc49f5eb
commit 6d0e66c23e
25 changed files with 658 additions and 132 deletions
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35
src/webp/encode.h
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@ -14,7 +14,7 @@
#include <stdlib.h>
#include "webp/types.h"
#include "./types.h"
#if defined(__cplusplus) || defined(c_plusplus)
extern "C" {
@ -122,6 +122,7 @@ typedef struct {
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
} WebPAuxStats;
// Signature for output function. Should return 1 if writing was successful.
@ -130,9 +131,24 @@ typedef struct {
typedef int (*WebPWriterFunction)(const uint8_t* data, size_t data_size,
const WebPPicture* const picture);
typedef enum {
// chroma sampling
WEBP_YUV420 = 0, // 4:2:0
WEBP_YUV422 = 1, // 4:2:2
WEBP_YUV444 = 2, // 4:4:4
WEBP_YUV400 = 3, // grayscale
WEBP_CSP_UV_MASK = 3, // bit-mask to get the UV sampling factors
// alpha channel variants
WEBP_YUV420A = 4,
WEBP_YUV422A = 5,
WEBP_YUV444A = 6,
WEBP_YUV400A = 7, // grayscale + alpha
WEBP_CSP_ALPHA_BIT = 4 // bit that is set if alpha is present
} WebPEncCSP;
struct WebPPicture {
// input
int colorspace; // colorspace: should be 0 for now (=Y'CbCr).
WebPEncCSP colorspace; // colorspace: should be YUV420 for now (=Y'CbCr).
int width, height; // dimensions.
uint8_t *y, *u, *v; // pointers to luma/chroma planes.
int y_stride, uv_stride; // luma/chroma strides.
@ -155,6 +171,10 @@ struct WebPPicture {
// where to store statistics, if not NULL:
WebPAuxStats* stats;
// original samples (for non-YUV420 modes)
uint8_t *u0, *v0;
int uv0_stride;
};
// Internal, version-checked, entry point
@ -171,15 +191,11 @@ static inline int WebPPictureInit(WebPPicture* const picture) {
// WebPPicture utils
// Convenience allocation / deallocation based on picture->width/height:
// Allocate y/u/v buffers as per width/height specification.
// Allocate y/u/v buffers as per colorspace/width/height specification.
// Note! This function will free the previous buffer if needed.
// Returns 0 in case of memory error.
int WebPPictureAlloc(WebPPicture* const picture);
// This function will add storage for a transparency plane to a picture, using
// its width and depth.
int WebPPictureAddAlphaPlane(WebPPicture* const picture);
// Release memory allocated by WebPPictureAlloc() or WebPPictureImport*()
// Note that this function does _not_ free the memory pointed to by 'picture'.
void WebPPictureFree(WebPPicture* const picture);
@ -194,6 +210,11 @@ int WebPPictureCopy(const WebPPicture* const src, WebPPicture* const dst);
int WebPPictureCrop(WebPPicture* const picture,
int left, int top, int width, int height);
// Rescale a picture to new dimension width x height.
// Now gamma correction is applied.
// Returns false in case of error (invalid parameter or insufficient memory).
int WebPPictureRescale(WebPPicture* const 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.