jsvpx
Version:
Javascript implementation of libvpx
258 lines (212 loc) • 7.5 kB
JavaScript
'use strict';
var VPX_IMG_FMT_PLANAR = 0x100;
var VPX_IMG_FMT_UV_FLIP = 0x200;
var VPX_IMG_FMT_HAS_ALPHA = 0x400;
//Image format codes
var VPX_IMG_FMT_NONE = 0;
var VPX_IMG_FMT_RGB24 = 1;
var VPX_IMG_FMT_RGB32 = 2;
var VPX_IMG_FMT_RGB565 = 3;
var VPX_IMG_FMT_RGB555 = 4;
var VPX_IMG_FMT_UYVY = 5;
var VPX_IMG_FMT_YUY2 = 6;
var VPX_IMG_FMT_YVYU = 7;
var VPX_IMG_FMT_BGR24 = 8;
var VPX_IMG_FMT_RGB32_LE = 9;
var VPX_IMG_FMT_ARGB = 10;
var VPX_IMG_FMT_ARGB_LE = 11;
var VPX_IMG_FMT_RGB565_LE = 12;
var VPX_IMG_FMT_RGB555_LE = 13;
var VPX_IMG_FMT_YV12 = VPX_IMG_FMT_PLANAR | VPX_IMG_FMT_UV_FLIP | 1;
var VPX_IMG_FMT_I420 = VPX_IMG_FMT_PLANAR | 2;
var VPX_IMG_FMT_VPXYV12 = VPX_IMG_FMT_PLANAR | VPX_IMG_FMT_UV_FLIP | 3;
var VPX_IMG_FMT_VPXI420 = VPX_IMG_FMT_PLANAR | 4;
var VPX_PLANE_PACKED = 0; /**< To be used for all packed formats */
var VPX_PLANE_Y = 0; /**< Y (Luminance) plane */
var VPX_PLANE_U = 1; /**< U (Chroma) plane */
var VPX_PLANE_V = 2; /**< V (Chroma) plane */
var VPX_PLANE_ALPHA = 3; /**< A (Transparency) plane */
var PLANE_PACKED = VPX_PLANE_PACKED;
var PLANE_Y = VPX_PLANE_Y;
var PLANE_U = VPX_PLANE_U;
var PLANE_V = VPX_PLANE_V;
var PLANE_ALPHA = VPX_PLANE_ALPHA;
Uint8ClampedArray.prototype.data_32 = null;
Uint8Array.prototype.data_32 = null;
/**
* typedef struct vpx_image
* vpx_image_t is alias for vpx_image
*/
class vpx_image_t {
constructor() {
this.fmt = 0; //can probably be uint
/* Image storage dimensions */
this.w = 0; // uint struct0
this.h = 0; // uint struct1
/* Image display dimensions */
this.d_w = 0; //uint struct2
this.d_h = 0; //uint struct3
/* Chroma subsampling info */
this.x_chroma_shift = 0; //uint
this.y_chroma_shift = 0; // uint
//this.planes = [0,0,0,0];//yuva
this.planes_off = new Int32Array(4); // yuva
this.stride = new Int32Array(4);
this.bps = 0; // int
this.user_priv = 0;
this.img_data = null;
this.img_data_off = 0; //uint
this.img_data_owner = 0; //int
this.self_allocd = 0; //int
}
}
function vpx_img_set_rect(img, x, y, w, h) {
var data = 0;
var data_off = 0;
if (x + w <= img.w && y + h <= img.h) {
img.d_w = w;
img.d_h = h;
/* Calculate plane pointers */
if ((img.fmt & VPX_IMG_FMT_PLANAR) === 0) {
img.img_data_off + (x * img.bps >> 3 + y * img.stride[VPX_PLANE_PACKED]) | 0;
} else {
data = img.img_data;
data_off = img.img_data_off;
if (img.fmt & VPX_IMG_FMT_HAS_ALPHA) {
img.planes_off[VPX_PLANE_ALPHA] =
data_off + x + y * img.stride[VPX_PLANE_ALPHA];
data_off += img.h * img.stride[VPX_PLANE_ALPHA];
}
img.planes_off[VPX_PLANE_Y] = data_off + x + y * img.stride[VPX_PLANE_Y];
data_off += img.h * img.stride[VPX_PLANE_Y];
if (!(img.fmt & VPX_IMG_FMT_UV_FLIP)) {
img.planes_off[VPX_PLANE_U] = data_off
+ (x >> img.x_chroma_shift)
+ (y >> img.y_chroma_shift) * img.stride[VPX_PLANE_U];
data_off += (img.h >> img.y_chroma_shift) * img.stride[VPX_PLANE_U];
img.planes_off[VPX_PLANE_V] = data_off
+ (x >> img.x_chroma_shift)
+ (y >> img.y_chroma_shift) * img.stride[VPX_PLANE_V];
} else {
img.planes_off[VPX_PLANE_V] = data_off
+ (x >> img.x_chroma_shift)
+ (y >> img.y_chroma_shift) * img.stride[VPX_PLANE_V];
data_off += (img.h >> img.y_chroma_shift) * img.stride[VPX_PLANE_V];
img.planes_off[VPX_PLANE_U] = data_off
+ (x >> img.x_chroma_shift)
+ (y >> img.y_chroma_shift) * img.stride[VPX_PLANE_U];
}
}
return 0;
}
return -1;
}
function img_alloc_helper(img, fmt, d_w, d_h, stride_align, img_data) {
var h = 0;
var w = 0;
var s = 0;
var xcs = 0;
var ycs = 0;
var bps = 0;
var align = 0;
/* Treat align==0 like align==1 */
if (!stride_align)
stride_align = 1;
/* Validate alignment (must be power of 2) */
if (stride_align & (stride_align - 1))
console.warn('Invalid stride align');
/* Get sample size for img format */
switch (fmt) {
case VPX_IMG_FMT_RGB32:
case VPX_IMG_FMT_RGB32_LE:
case VPX_IMG_FMT_ARGB:
case VPX_IMG_FMT_ARGB_LE:
bps = 32;
break;
case VPX_IMG_FMT_RGB24:
case VPX_IMG_FMT_BGR24:
bps = 24;
break;
case VPX_IMG_FMT_RGB565:
case VPX_IMG_FMT_RGB565_LE:
case VPX_IMG_FMT_RGB555:
case VPX_IMG_FMT_RGB555_LE:
case VPX_IMG_FMT_UYVY:
case VPX_IMG_FMT_YUY2:
case VPX_IMG_FMT_YVYU:
bps = 16;
break;
case VPX_IMG_FMT_I420:
case VPX_IMG_FMT_YV12:
case VPX_IMG_FMT_VPXI420:
case VPX_IMG_FMT_VPXYV12:
bps = 12;
break;
default:
bps = 16;
break;
}
/* Get chroma shift values for img format */
switch (fmt) {
case VPX_IMG_FMT_I420:
case VPX_IMG_FMT_YV12:
case VPX_IMG_FMT_VPXI420:
case VPX_IMG_FMT_VPXYV12:
xcs = 1;
break;
default:
xcs = 0;
break;
}
switch (fmt) {
case VPX_IMG_FMT_I420:
case VPX_IMG_FMT_YV12:
case VPX_IMG_FMT_VPXI420:
case VPX_IMG_FMT_VPXYV12:
ycs = 1;
break;
default:
ycs = 0;
break;
}
/* Calculate storage sizes given the chroma subsampling */
align = ((1 << xcs) - 1) | 0;
w = ((d_w + align) & ~align) | 0;
align = ((1 << ycs) - 1) | 0;
h = ((d_h + align) & ~align) | 0;
s = ((fmt & VPX_IMG_FMT_PLANAR) ? w : bps * w >> 3) | 0;
s = ((s + stride_align - 1) & ~(stride_align - 1)) | 0;
/* Allocate the new image */
//todo: reset
img.img_data = img_data;
if (img_data === null) {
} else {
var size = 0;
if ((fmt & VPX_IMG_FMT_PLANAR) === 0) {
size = h * s;
} else {
size = (h * w * bps) >> 3;
}
//img.img_data = new Uint8ClampedArray(size);
img.img_data = new Uint8Array(size);
img.img_data.data_32 = new Uint32Array(img.img_data.buffer);
img.img_data.data_16 = new Uint16Array(img.img_data.buffer);
img.img_data_owner = 1;
}
img.fmt = fmt;
img.w = w;
img.h = h;
img.x_chroma_shift = xcs;
img.y_chroma_shift = ycs;
img.bps = bps;
/* Calculate strides */
img.stride[VPX_PLANE_Y] = img.stride[VPX_PLANE_ALPHA] = s;
img.stride[VPX_PLANE_U] = img.stride[VPX_PLANE_V] = s >> xcs;
/* Default viewport to entire image */
if (vpx_img_set_rect(img, 0, 0, d_w, d_h) === 0)
return img;
}
module.exports = {};
module.exports.vpx_img_set_rect = vpx_img_set_rect;
module.exports.img_alloc_helper = img_alloc_helper;
module.exports.vpx_image_t = vpx_image_t;