/*!\brief Open a descriptor, using existing storage for the underlying image
*
* Returns a descriptor for storing an image of the given format. The
* storage for descriptor has been allocated elsewhere, and a descriptor is
* desired to "wrap" that storage.
*
* \param[in] img Pointer to storage for descriptor. If this
* parameter is NULL, the storage for the descriptor
* will be allocated on the heap.
* \param[in] fmt Format for the image
* \param[in] d_w Width of the image
* \param[in] d_h Height of the image
* \param[in] stride_align Alignment, in bytes, of each row in the image.
* \param[in] img_data Storage to use for the image
*
* \return Returns a pointer to the initialized image descriptor. If the img
* parameter is non-null, the value of the img parameter will be
* returned.
*/
//vpx_image_t* vpx_img_wrap(vpx_image_t* img, vpx_img_fmt_t fmt, unsigned int d_w,
// unsigned int d_h, unsigned int stride_align,
// unsigned char* img_data);
public vpx_image_t vpx_img_wrap(vpx_image_t img, vpx_img_fmt_t fmt, uint d_w,
uint d_h, uint stride_align, byte *img_data)
{
/* By setting buf_align = 1, we don't change buffer alignment in this
* function. */
return(img_alloc_helper(img, fmt, d_w, d_h, 1, stride_align, img_data));
}
private static vpx_image_t img_alloc_helper(vpx_image_t img, vpx_img_fmt_t fmt,
uint d_w, uint d_h,
uint buf_align,
uint stride_align,
byte *img_data)
{
uint h, w, s, xcs, ycs, bps;
uint stride_in_bytes;
int align;
/* Treat align==0 like align==1 */
if (buf_align == 0)
{
buf_align = 1;
}
/* Validate alignment (must be power of 2) */
if ((buf_align & (buf_align - 1)) != 0)
{
goto fail;
}
/* Treat align==0 like align==1 */
if (stride_align == 0)
{
stride_align = 1;
}
/* Validate alignment (must be power of 2) */
if ((stride_align & (stride_align - 1)) != 0)
{
goto fail;
}
/* Get sample size for this format */
switch (fmt)
{
case vpx_img_fmt_t.VPX_IMG_FMT_I420:
case vpx_img_fmt_t.VPX_IMG_FMT_YV12:
case vpx_img_fmt_t.VPX_IMG_FMT_NV12: bps = 12; break;
case vpx_img_fmt_t.VPX_IMG_FMT_I422:
case vpx_img_fmt_t.VPX_IMG_FMT_I440: bps = 16; break;
case vpx_img_fmt_t.VPX_IMG_FMT_I444: bps = 24; break;
case vpx_img_fmt_t.VPX_IMG_FMT_I42016: bps = 24; break;
case vpx_img_fmt_t.VPX_IMG_FMT_I42216:
case vpx_img_fmt_t.VPX_IMG_FMT_I44016: bps = 32; break;
case vpx_img_fmt_t.VPX_IMG_FMT_I44416: bps = 48; break;
default: bps = 16; break;
}
/* Get chroma shift values for this format */
// For VPX_IMG_FMT_NV12, xcs needs to be 0 such that UV data is all read at
// one time.
switch (fmt)
{
case vpx_img_fmt_t.VPX_IMG_FMT_I420:
case vpx_img_fmt_t.VPX_IMG_FMT_YV12:
case vpx_img_fmt_t.VPX_IMG_FMT_I422:
case vpx_img_fmt_t.VPX_IMG_FMT_I42016:
case vpx_img_fmt_t.VPX_IMG_FMT_I42216: xcs = 1; break;
default: xcs = 0; break;
}
switch (fmt)
{
case vpx_img_fmt_t.VPX_IMG_FMT_I420:
case vpx_img_fmt_t.VPX_IMG_FMT_NV12:
case vpx_img_fmt_t.VPX_IMG_FMT_I440:
case vpx_img_fmt_t.VPX_IMG_FMT_YV12:
case vpx_img_fmt_t.VPX_IMG_FMT_I42016:
case vpx_img_fmt_t.VPX_IMG_FMT_I44016: ycs = 1; break;
default: ycs = 0; break;
}
/* Calculate storage sizes. If the buffer was allocated externally, the width
* and height shouldn't be adjusted. */
w = d_w;
h = d_h;
s = (((int)fmt & vpx_image_t.VPX_IMG_FMT_PLANAR) > 0) ? w : bps * w / 8;
s = (s + stride_align - 1) & ~(stride_align - 1);
stride_in_bytes = (((int)fmt & vpx_image_t.VPX_IMG_FMT_HIGHBITDEPTH) > 0) ? s * 2 : s;
/* Allocate the new image */
if (img == null)
{
//img = (vpx_image_t*)calloc(1, sizeof(vpx_image_t));
//if (!img) goto fail;
img = new vpx_image_t();
img.self_allocd = 1;
}
else
{
//memset(img, 0, sizeof(vpx_image_t));
}
img.img_data = img_data;
if (img_data == null)
{
ulong alloc_size;
/* Calculate storage sizes given the chroma subsampling */
align = (1 << (int)xcs) - 1;
w = (uint)((d_w + align) & ~align);
align = (1 << (int)ycs) - 1;
h = (uint)((d_h + align) & ~align);
s = (((int)fmt & vpx_image_t.VPX_IMG_FMT_PLANAR) > 0) ? w : bps * w / 8;
s = (s + stride_align - 1) & ~(stride_align - 1);
stride_in_bytes = (((int)fmt & vpx_image_t.VPX_IMG_FMT_HIGHBITDEPTH) > 0) ? s * 2 : s;
alloc_size = (((int)fmt & vpx_image_t.VPX_IMG_FMT_PLANAR) > 0) ? (ulong)h * s * bps / 8
: (ulong)h * s;
//if (alloc_size != (size_t)alloc_size) goto fail;
//img.img_data = (byte*)vpx_memalign(buf_align, (size_t)alloc_size);
img.img_data = (byte *)Marshal.AllocHGlobal((int)alloc_size);
img.img_data_owner = 1;
}
if (img.img_data == null)
{
goto fail;
}
img.fmt = fmt;
img.bit_depth = (((int)fmt & vpx_image_t.VPX_IMG_FMT_HIGHBITDEPTH) > 0) ? 16U : 8U;
img.w = w;
img.h = h;
img.x_chroma_shift = xcs;
img.y_chroma_shift = ycs;
img.bps = (int)bps;
/* Calculate strides */
img.stride[vpx_image_t.VPX_PLANE_Y] = img.stride[vpx_image_t.VPX_PLANE_ALPHA] = (int)stride_in_bytes;
img.stride[vpx_image_t.VPX_PLANE_U] = img.stride[vpx_image_t.VPX_PLANE_V] = (int)(stride_in_bytes >> (int)xcs);
/* Default viewport to entire image */
if (vpx_img_set_rect(img, 0, 0, d_w, d_h) == 0)
{
return(img);
}
fail:
vpx_img_free(img);
return(null);
}
/*!\brief Open a descriptor, allocating storage for the underlying image
*
* Returns a descriptor for storing an image of the given format. The
* storage for the descriptor is allocated on the heap.
*
* \param[in] img Pointer to storage for descriptor. If this parameter
* is NULL, the storage for the descriptor will be
* allocated on the heap.
* \param[in] fmt Format for the image
* \param[in] d_w Width of the image
* \param[in] d_h Height of the image
* \param[in] align Alignment, in bytes, of the image buffer and
* each row in the image(stride).
*
* \return Returns a pointer to the initialized image descriptor. If the img
* parameter is non-null, the value of the img parameter will be
* returned.
*/
//vpx_image_t* vpx_img_alloc(vpx_image_t* img, vpx_img_fmt_t fmt,
// unsigned int d_w, unsigned int d_h,
// unsigned int align);
public static vpx_image_t vpx_img_alloc(vpx_image_t img, vpx_img_fmt_t fmt,
uint d_w, uint d_h, uint align)
{
return(img_alloc_helper(img, fmt, d_w, d_h, align, align, null));
}
