/*
* Tries to handle the image with PIEX. If PIEX returns kOk and finds the preview image, create a
* SkJpegCodec. If PIEX returns kFail, then the file is invalid, return nullptr. In other cases,
* fallback to create SkRawCodec for DNG images.
*/
SkCodec* SkRawCodec::NewFromStream(SkStream* stream) {
SkAutoTDelete<SkRawStream> rawStream;
if (is_asset_stream(*stream)) {
rawStream.reset(new SkRawAssetStream(stream));
} else {
rawStream.reset(new SkRawBufferedStream(stream));
}
// Does not take the ownership of rawStream.
SkPiexStream piexStream(rawStream.get());
::piex::PreviewImageData imageData;
if (::piex::IsRaw(&piexStream)) {
::piex::Error error = ::piex::GetPreviewImageData(&piexStream, &imageData);
if (error == ::piex::Error::kOk && imageData.preview.length > 0) {
// transferBuffer() is destructive to the rawStream. Abandon the rawStream after this
// function call.
// FIXME: one may avoid the copy of memoryStream and use the buffered rawStream.
SkMemoryStream* memoryStream =
rawStream->transferBuffer(imageData.preview.offset, imageData.preview.length);
return memoryStream ? SkJpegCodec::NewFromStream(memoryStream) : nullptr;
} else if (error == ::piex::Error::kFail) {
return nullptr;
}
}
// Takes the ownership of the rawStream.
SkAutoTDelete<SkDngImage> dngImage(SkDngImage::NewFromStream(rawStream.release()));
if (!dngImage) {
return nullptr;
}
return new SkRawCodec(dngImage.release());
}
