1 // Copyright (c) the JPEG XL Project Authors. All rights reserved.
2 //
3 // Use of this source code is governed by a BSD-style
4 // license that can be found in the LICENSE file.
5
6 #include "lib/jxl/enc_toc.h"
7
8 #include <stdint.h>
9
10 #include "lib/jxl/aux_out_fwd.h"
11 #include "lib/jxl/coeff_order.h"
12 #include "lib/jxl/coeff_order_fwd.h"
13 #include "lib/jxl/common.h"
14 #include "lib/jxl/enc_coeff_order.h"
15 #include "lib/jxl/field_encodings.h"
16 #include "lib/jxl/fields.h"
17 #include "lib/jxl/toc.h"
18
19 namespace jxl {
WriteGroupOffsets(const std::vector<BitWriter> & group_codes,const std::vector<coeff_order_t> * permutation,BitWriter * JXL_RESTRICT writer,AuxOut * aux_out)20 Status WriteGroupOffsets(const std::vector<BitWriter>& group_codes,
21 const std::vector<coeff_order_t>* permutation,
22 BitWriter* JXL_RESTRICT writer, AuxOut* aux_out) {
23 BitWriter::Allotment allotment(writer, MaxBits(group_codes.size()));
24 if (permutation && !group_codes.empty()) {
25 // Don't write a permutation at all for an empty group_codes.
26 writer->Write(1, 1); // permutation
27 JXL_DASSERT(permutation->size() == group_codes.size());
28 EncodePermutation(permutation->data(), /*skip=*/0, permutation->size(),
29 writer, /* layer= */ 0, aux_out);
30
31 } else {
32 writer->Write(1, 0); // no permutation
33 }
34 writer->ZeroPadToByte(); // before TOC entries
35
36 for (size_t i = 0; i < group_codes.size(); i++) {
37 JXL_ASSERT(group_codes[i].BitsWritten() % kBitsPerByte == 0);
38 const size_t group_size = group_codes[i].BitsWritten() / kBitsPerByte;
39 JXL_RETURN_IF_ERROR(U32Coder::Write(kTocDist, group_size, writer));
40 }
41 writer->ZeroPadToByte(); // before first group
42 ReclaimAndCharge(writer, &allotment, kLayerTOC, aux_out);
43 return true;
44 }
45
46 } // namespace jxl
47