//------------------------------------------------------------------------------
static byte* Decode(WEBP_CSP_MODE mode, byte* data,
uint data_size, int* width, int* height,
WebPDecBuffer* keep_info)
{
WebPDecParams params;
WebPDecBuffer output;
WebPInitDecBuffer(&output);
WebPResetDecParams(¶ms);
params.output = &output;
output.colorspace = mode;
// Retrieve (and report back) the required dimensions from bitstream.
if (!WebPGetInfo(data, data_size, &output.width, &output.height)) {
return null;
}
if (width != null) *width = output.width;
if (height != null) *height = output.height;
// Decode
if (DecodeInto(data, data_size, ¶ms) != VP8_STATUS_OK) {
return null;
}
if (keep_info != null) { // keep track of the side-info
WebPCopyDecBuffer(&output, keep_info);
}
// return decoded samples (don't clear 'output'!)
return (mode >= MODE_YUV) ? output.u.YUVA.y : output.u.RGBA.rgba;
}
static void WebPCopyDecBuffer(WebPDecBuffer src, WebPDecBuffer dst)
{
throw(new NotImplementedException("Should copy every field"));
/*
if (src != null && dst != null) {
*dst = *src;
if (src.private_memory != null) {
dst.is_external_memory = 1; // dst buffer doesn't own the memory.
dst.private_memory = null;
}
}
*/
}
/// <summary>
/// Copy and transfer ownership from src to dst (beware of parameter order!)
/// </summary>
/// <param name="src"></param>
/// <param name="dst"></param>
void WebPGrabDecBuffer(WebPDecBuffer src, WebPDecBuffer dst)
{
throw (new NotImplementedException("Should copy every field"));
/*
if (src != null && dst != null)
{
*dst = *src;
if (src.private_memory != null) {
src.is_external_memory = 1; // src relinquishes ownership
src.private_memory = null;
}
*/
}
VP8StatusCode WebPAllocateDecBuffer(int w, int h, WebPDecoderOptions options, WebPDecBuffer _out)
{
if (_out == null || w <= 0 || h <= 0) {
return VP8_STATUS_INVALID_PARAM;
}
if (options != null) { // First, apply options if there is any.
if (options.use_cropping) {
int cw = options.crop_width;
int ch = options.crop_height;
int x = options.crop_left & ~1;
int y = options.crop_top & ~1;
if (x < 0 || y < 0 || cw <= 0 || ch <= 0 || x + cw > w || y + ch > h) {
return VP8_STATUS_INVALID_PARAM; // out of frame boundary.
}
w = cw;
h = ch;
}
if (options.use_scaling) {
if (options.scaled_width <= 0 || options.scaled_height <= 0) {
return VP8_STATUS_INVALID_PARAM;
}
w = options.scaled_width;
h = options.scaled_height;
}
}
_out.width = w;
_out.height = h;
// Then, allocate buffer for real
return _out.AllocateBuffer();
}