webpdec.c
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// 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.
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#ifdef HAVE_CONFIG_H
#include "webp/config.h"
#endif
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#include "./webpdec.h"
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#include <assert.h>
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#include <stdio.h>
#include <stdlib.h>
#include "webp/decode.h"
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#include "webp/demux.h"
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#include "webp/encode.h"
#include "./imageio_util.h"
#include "./metadata.h"
//------------------------------------------------------------------------------
// WebP decoding
static const char* const kStatusMessages[VP8_STATUS_NOT_ENOUGH_DATA + 1] = {
"OK", "OUT_OF_MEMORY", "INVALID_PARAM", "BITSTREAM_ERROR",
"UNSUPPORTED_FEATURE", "SUSPENDED", "USER_ABORT", "NOT_ENOUGH_DATA"
};
static void PrintAnimationWarning(const WebPDecoderConfig* const config) {
if (config->input.has_animation) {
fprintf(stderr,
"Error! Decoding of an animated WebP file is not supported.\n"
" Use webpmux to extract the individual frames or\n"
" vwebp to view this image.\n");
}
}
void PrintWebPError(const char* const in_file, int status) {
fprintf(stderr, "Decoding of %s failed.\n", in_file);
fprintf(stderr, "Status: %d", status);
if (status >= VP8_STATUS_OK && status <= VP8_STATUS_NOT_ENOUGH_DATA) {
fprintf(stderr, "(%s)", kStatusMessages[status]);
}
fprintf(stderr, "\n");
}
int LoadWebP(const char* const in_file,
const uint8_t** data, size_t* data_size,
WebPBitstreamFeatures* bitstream) {
VP8StatusCode status;
WebPBitstreamFeatures local_features;
if (!ImgIoUtilReadFile(in_file, data, data_size)) return 0;
if (bitstream == NULL) {
bitstream = &local_features;
}
status = WebPGetFeatures(*data, *data_size, bitstream);
if (status != VP8_STATUS_OK) {
free((void*)*data);
*data = NULL;
*data_size = 0;
PrintWebPError(in_file, status);
return 0;
}
return 1;
}
//------------------------------------------------------------------------------
VP8StatusCode DecodeWebP(const uint8_t* const data, size_t data_size,
WebPDecoderConfig* const config) {
if (config == NULL) return VP8_STATUS_INVALID_PARAM;
PrintAnimationWarning(config);
return WebPDecode(data, data_size, config);
}
VP8StatusCode DecodeWebPIncremental(
const uint8_t* const data, size_t data_size,
WebPDecoderConfig* const config) {
VP8StatusCode status = VP8_STATUS_OK;
if (config == NULL) return VP8_STATUS_INVALID_PARAM;
PrintAnimationWarning(config);
// Decoding call.
{
WebPIDecoder* const idec = WebPIDecode(data, data_size, config);
if (idec == NULL) {
fprintf(stderr, "Failed during WebPINewDecoder().\n");
return VP8_STATUS_OUT_OF_MEMORY;
} else {
status = WebPIUpdate(idec, data, data_size);
WebPIDelete(idec);
}
}
return status;
}
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// -----------------------------------------------------------------------------
// Metadata
static int ExtractMetadata(const uint8_t* const data, size_t data_size,
Metadata* const metadata) {
WebPData webp_data = { data, data_size };
WebPDemuxer* const demux = WebPDemux(&webp_data);
WebPChunkIterator chunk_iter;
uint32_t flags;
if (demux == NULL) return 0;
assert(metadata != NULL);
flags = WebPDemuxGetI(demux, WEBP_FF_FORMAT_FLAGS);
if ((flags & ICCP_FLAG) && WebPDemuxGetChunk(demux, "ICCP", 1, &chunk_iter)) {
MetadataCopy((const char*)chunk_iter.chunk.bytes, chunk_iter.chunk.size,
&metadata->iccp);
WebPDemuxReleaseChunkIterator(&chunk_iter);
}
if ((flags & EXIF_FLAG) && WebPDemuxGetChunk(demux, "EXIF", 1, &chunk_iter)) {
MetadataCopy((const char*)chunk_iter.chunk.bytes, chunk_iter.chunk.size,
&metadata->exif);
WebPDemuxReleaseChunkIterator(&chunk_iter);
}
if ((flags & XMP_FLAG) && WebPDemuxGetChunk(demux, "XMP ", 1, &chunk_iter)) {
MetadataCopy((const char*)chunk_iter.chunk.bytes, chunk_iter.chunk.size,
&metadata->xmp);
WebPDemuxReleaseChunkIterator(&chunk_iter);
}
WebPDemuxDelete(demux);
return 1;
}
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// -----------------------------------------------------------------------------
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;
if (data == NULL || data_size == 0 || pic == NULL) return 0;
if (!WebPInitDecoderConfig(&config)) {
fprintf(stderr, "Library version mismatch!\n");
return 0;
}
status = WebPGetFeatures(data, data_size, bitstream);
if (status != VP8_STATUS_OK) {
PrintWebPError("input data", status);
return 0;
}
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do {
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const int has_alpha = keep_alpha && bitstream->has_alpha;
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uint64_t stride;
pic->width = bitstream->width;
pic->height = bitstream->height;
if (pic->use_argb) {
stride = (uint64_t)bitstream->width * 4;
} else {
stride = (uint64_t)bitstream->width * (has_alpha ? 5 : 3) / 2;
pic->colorspace = has_alpha ? WEBP_YUV420A : WEBP_YUV420;
}
if (!ImgIoUtilCheckSizeArgumentsOverflow(stride, bitstream->height)) {
status = VP8_STATUS_OUT_OF_MEMORY;
break;
}
ok = WebPPictureAlloc(pic);
if (!ok) {
status = VP8_STATUS_OUT_OF_MEMORY;
break;
}
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if (pic->use_argb) {
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#ifdef WORDS_BIGENDIAN
output_buffer->colorspace = MODE_ARGB;
#else
output_buffer->colorspace = MODE_BGRA;
#endif
output_buffer->u.RGBA.rgba = (uint8_t*)pic->argb;
output_buffer->u.RGBA.stride = pic->argb_stride * sizeof(uint32_t);
output_buffer->u.RGBA.size = output_buffer->u.RGBA.stride * pic->height;
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} else {
output_buffer->colorspace = has_alpha ? MODE_YUVA : MODE_YUV;
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output_buffer->u.YUVA.y = pic->y;
output_buffer->u.YUVA.u = pic->u;
output_buffer->u.YUVA.v = pic->v;
output_buffer->u.YUVA.a = has_alpha ? pic->a : NULL;
output_buffer->u.YUVA.y_stride = pic->y_stride;
output_buffer->u.YUVA.u_stride = pic->uv_stride;
output_buffer->u.YUVA.v_stride = pic->uv_stride;
output_buffer->u.YUVA.a_stride = has_alpha ? pic->a_stride : 0;
output_buffer->u.YUVA.y_size = pic->height * pic->y_stride;
output_buffer->u.YUVA.u_size = (pic->height + 1) / 2 * pic->uv_stride;
output_buffer->u.YUVA.v_size = (pic->height + 1) / 2 * pic->uv_stride;
output_buffer->u.YUVA.a_size = pic->height * pic->a_stride;
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output_buffer->is_external_memory = 1;
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status = DecodeWebP(data, data_size, &config);
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ok = (status == VP8_STATUS_OK);
if (ok && !keep_alpha && pic->use_argb) {
// Need to wipe out the alpha value, as requested.
int x, y;
uint32_t* argb = pic->argb;
for (y = 0; y < pic->height; ++y) {
for (x = 0; x < pic->width; ++x) argb[x] |= 0xff000000u;
argb += pic->argb_stride;
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}
}
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} while (0); // <- so we can 'break' out of the loop
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if (status != VP8_STATUS_OK) {
PrintWebPError("input data", status);
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ok = 0;
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}
WebPFreeDecBuffer(output_buffer);
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if (ok && metadata != NULL) {
ok = ExtractMetadata(data, data_size, metadata);
if (!ok) {
PrintWebPError("metadata", VP8_STATUS_BITSTREAM_ERROR);
}
}
if (!ok) WebPPictureFree(pic);
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return ok;
}
// -----------------------------------------------------------------------------