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imagedec: support metadata reading for WebP image decoding

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Needs to link imagedec.a to demux/libwebpdemux.a

Change-Id: Id8f4068718b0e4a1e84607bccd5af5419120c231
This commit is contained in:
Pascal Massimino
2017-03-02 08:45:42 -08:00
committed by James Zern
parent c4cc114785
commit 641cedccd3
10 changed files with 88 additions and 23 deletions
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51
imageio/webpdec.c
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@ -15,10 +15,12 @@
#include "./webpdec.h"
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include "webp/decode.h"
#include "webp/demux.h"
#include "webp/encode.h"
#include "./imageio_util.h"
#include "./metadata.h"
@ -102,6 +104,40 @@ VP8StatusCode DecodeWebPIncremental(
return status;
}
// -----------------------------------------------------------------------------
// 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;
}
// -----------------------------------------------------------------------------
int ReadWebP(const uint8_t* const data, size_t data_size,
@ -115,11 +151,6 @@ int ReadWebP(const uint8_t* const data, size_t data_size,
if (data == NULL || data_size == 0 || pic == NULL) return 0;
// 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;
@ -181,7 +212,6 @@ int ReadWebP(const uint8_t* const data, size_t data_size,
status = DecodeWebP(data, data_size, &config);
ok = (status == VP8_STATUS_OK);
if (!ok) WebPPictureFree(pic);
if (ok && !keep_alpha && pic->use_argb) {
// Need to wipe out the alpha value, as requested.
int x, y;
@ -195,9 +225,18 @@ int ReadWebP(const uint8_t* const data, size_t data_size,
if (status != VP8_STATUS_OK) {
PrintWebPError("input data", status);
ok = 0;
}
WebPFreeDecBuffer(output_buffer);
if (ok && metadata != NULL) {
ok = ExtractMetadata(data, data_size, metadata);
if (!ok) {
PrintWebPError("metadata", VP8_STATUS_BITSTREAM_ERROR);
}
}
if (!ok) WebPPictureFree(pic);
return ok;
}