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// Copyright 2016 The Draco Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
#include "draco/compression/attributes/sequential_quantization_attribute_decoder.h"
#include "draco/attributes/attribute_quantization_transform.h"
#include "draco/core/quantization_utils.h"
namespace draco {
SequentialQuantizationAttributeDecoder::SequentialQuantizationAttributeDecoder()
: quantization_bits_(-1), max_value_dif_(0.f) {}
bool SequentialQuantizationAttributeDecoder::Init(PointCloudDecoder *decoder,
int attribute_id) {
if (!SequentialIntegerAttributeDecoder::Init(decoder, attribute_id)) {
return false;
}
const PointAttribute *const attribute =
decoder->point_cloud()->attribute(attribute_id);
// Currently we can quantize only floating point arguments.
if (attribute->data_type() != DT_FLOAT32) {
return false;
}
return true;
}
bool SequentialQuantizationAttributeDecoder::DecodeIntegerValues(
const std::vector<PointIndex> &point_ids, DecoderBuffer *in_buffer) {
#ifdef DRACO_BACKWARDS_COMPATIBILITY_SUPPORTED
if (decoder()->bitstream_version() < DRACO_BITSTREAM_VERSION(2, 0) &&
!DecodeQuantizedDataInfo()) {
return false;
}
#endif
return SequentialIntegerAttributeDecoder::DecodeIntegerValues(point_ids,
in_buffer);
}
bool SequentialQuantizationAttributeDecoder::
DecodeDataNeededByPortableTransform(
const std::vector<PointIndex> &point_ids, DecoderBuffer *in_buffer) {
if (decoder()->bitstream_version() >= DRACO_BITSTREAM_VERSION(2, 0)) {
// Decode quantization data here only for files with bitstream version 2.0+
if (!DecodeQuantizedDataInfo()) {
return false;
}
}
// Store the decoded transform data in portable attribute;
AttributeQuantizationTransform transform;
transform.SetParameters(quantization_bits_, min_value_.get(),
attribute()->num_components(), max_value_dif_);
return transform.TransferToAttribute(portable_attribute());
}
bool SequentialQuantizationAttributeDecoder::StoreValues(uint32_t num_values) {
return DequantizeValues(num_values);
}
bool SequentialQuantizationAttributeDecoder::DecodeQuantizedDataInfo() {
const int num_components = attribute()->num_components();
min_value_ = std::unique_ptr<float[]>(new float[num_components]);
if (!decoder()->buffer()->Decode(min_value_.get(),
sizeof(float) * num_components)) {
return false;
}
if (!decoder()->buffer()->Decode(&max_value_dif_)) {
return false;
}
uint8_t quantization_bits;
if (!decoder()->buffer()->Decode(&quantization_bits) ||
quantization_bits > 31) {
return false;
}
quantization_bits_ = quantization_bits;
return true;
}
bool SequentialQuantizationAttributeDecoder::DequantizeValues(
uint32_t num_values) {
// Convert all quantized values back to floats.
const int32_t max_quantized_value =
(1u << static_cast<uint32_t>(quantization_bits_)) - 1;
const int num_components = attribute()->num_components();
const int entry_size = sizeof(float) * num_components;
const std::unique_ptr<float[]> att_val(new float[num_components]);
int quant_val_id = 0;
int out_byte_pos = 0;
Dequantizer dequantizer;
if (!dequantizer.Init(max_value_dif_, max_quantized_value)) {
return false;
}
const int32_t *const portable_attribute_data = GetPortableAttributeData();
for (uint32_t i = 0; i < num_values; ++i) {
for (int c = 0; c < num_components; ++c) {
float value =
dequantizer.DequantizeFloat(portable_attribute_data[quant_val_id++]);
value = value + min_value_[c];
att_val[c] = value;
}
// Store the floating point value into the attribute buffer.
attribute()->buffer()->Write(out_byte_pos, att_val.get(), entry_size);
out_byte_pos += entry_size;
}
return true;
}
} // namespace draco
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