webp/examples/webpdec.c
Pascal Massimino ab8d669887 ReadWebP: avoid conversion to ARGB if final format is YUVA
Adds ExUtilCopyPlane() in example_utils.[ch], borrowed from
src/util/utils.h

(removes a TODO)

Change-Id: Iadfc19da3914c9439608f296e86225d279263566
2016-05-26 05:49:16 +00:00

96 lines
3.2 KiB
C

// Copyright 2014 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 decode.
#include "./webpdec.h"
#include <stdio.h>
#include <stdlib.h>
#include "webp/decode.h"
#include "webp/encode.h"
#include "./example_util.h"
#include "./metadata.h"
int ReadWebP(const uint8_t* const data, size_t data_size,
WebPPicture* const pic,
int keep_alpha, Metadata* const metadata) {
int ok = 0;
VP8StatusCode status = VP8_STATUS_OK;
WebPDecoderConfig config;
WebPDecBuffer* const output_buffer = &config.output;
WebPBitstreamFeatures* const bitstream = &config.input;
// TODO(jzern): add Exif/XMP/ICC extraction.
if (metadata != NULL) {
fprintf(stderr, "Warning: metadata extraction from WebP is unsupported.\n");
}
if (!WebPInitDecoderConfig(&config)) {
fprintf(stderr, "Library version mismatch!\n");
return 0;
}
status = WebPGetFeatures(data, data_size, bitstream);
if (status != VP8_STATUS_OK) {
ExUtilPrintWebPError("input data", status);
return 0;
}
{
const int has_alpha = keep_alpha && bitstream->has_alpha;
if (pic->use_argb) {
output_buffer->colorspace = has_alpha ? MODE_RGBA : MODE_RGB;
} else {
output_buffer->colorspace = has_alpha ? MODE_YUVA : MODE_YUV;
}
status = ExUtilDecodeWebP(data, data_size, 0, &config);
if (status == VP8_STATUS_OK) {
pic->width = output_buffer->width;
pic->height = output_buffer->height;
if (pic->use_argb) {
const uint8_t* const rgba = output_buffer->u.RGBA.rgba;
const int stride = output_buffer->u.RGBA.stride;
ok = has_alpha ? WebPPictureImportRGBA(pic, rgba, stride)
: WebPPictureImportRGB(pic, rgba, stride);
} else {
pic->colorspace = has_alpha ? WEBP_YUV420A : WEBP_YUV420;
ok = WebPPictureAlloc(pic);
if (!ok) {
status = VP8_STATUS_OUT_OF_MEMORY;
} else {
const WebPYUVABuffer* const yuva = &output_buffer->u.YUVA;
const int uv_width = (pic->width + 1) >> 1;
const int uv_height = (pic->height + 1) >> 1;
ExUtilCopyPlane(yuva->y, yuva->y_stride,
pic->y, pic->y_stride, pic->width, pic->height);
ExUtilCopyPlane(yuva->u, yuva->u_stride,
pic->u, pic->uv_stride, uv_width, uv_height);
ExUtilCopyPlane(yuva->v, yuva->v_stride,
pic->v, pic->uv_stride, uv_width, uv_height);
if (has_alpha) {
ExUtilCopyPlane(yuva->a, yuva->a_stride,
pic->a, pic->a_stride, pic->width, pic->height);
}
}
}
}
}
if (status != VP8_STATUS_OK) {
ExUtilPrintWebPError("input data", status);
}
WebPFreeDecBuffer(output_buffer);
return ok;
}
// -----------------------------------------------------------------------------