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// Copyright (c) the JPEG XL Project Authors. All rights reserved.
//
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
#include "lib/jxl/enc_toc.h"
#include <memory>
#include "lib/jxl/base/common.h"
#include "lib/jxl/base/status.h"
#include "lib/jxl/enc_aux_out.h"
#include "lib/jxl/enc_coeff_order.h"
#include "lib/jxl/field_encodings.h"
#include "lib/jxl/fields.h"
#include "lib/jxl/toc.h"
namespace jxl {
Status WriteGroupOffsets(
const std::vector<std::unique_ptr<BitWriter>>& group_codes,
const std::vector<coeff_order_t>& permutation,
BitWriter* JXL_RESTRICT writer, AuxOut* aux_out) {
return writer->WithMaxBits(
MaxBits(group_codes.size()), LayerType::Toc, aux_out, [&]() -> Status {
if (!permutation.empty() && !group_codes.empty()) {
// Don't write a permutation at all for an empty group_codes.
writer->Write(1, 1); // permutation
JXL_ENSURE(permutation.size() == group_codes.size());
JXL_RETURN_IF_ERROR(EncodePermutation(permutation.data(), /*skip=*/0,
permutation.size(), writer,
LayerType::Header, aux_out));
} else {
writer->Write(1, 0); // no permutation
}
writer->ZeroPadToByte(); // before TOC entries
for (const auto& bw : group_codes) {
JXL_ENSURE(bw->BitsWritten() % kBitsPerByte == 0);
const size_t group_size = bw->BitsWritten() / kBitsPerByte;
JXL_RETURN_IF_ERROR(U32Coder::Write(kTocDist, group_size, writer));
}
writer->ZeroPadToByte(); // before first group
return true;
});
}
} // namespace jxl