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/box_content_decoder.h"
7
8 #include "lib/jxl/sanitizers.h"
9
10 namespace jxl {
11
JxlBoxContentDecoder()12 JxlBoxContentDecoder::JxlBoxContentDecoder() {}
13
~JxlBoxContentDecoder()14 JxlBoxContentDecoder::~JxlBoxContentDecoder() {
15 if (brotli_dec) {
16 BrotliDecoderDestroyInstance(brotli_dec);
17 }
18 }
19
StartBox(bool brob_decode,bool box_until_eof,size_t contents_size)20 void JxlBoxContentDecoder::StartBox(bool brob_decode, bool box_until_eof,
21 size_t contents_size) {
22 if (brotli_dec) {
23 BrotliDecoderDestroyInstance(brotli_dec);
24 brotli_dec = nullptr;
25 }
26 header_done_ = false;
27 brob_decode_ = brob_decode;
28 box_until_eof_ = box_until_eof;
29 remaining_ = box_until_eof ? 0 : contents_size;
30 pos_ = 0;
31 }
32
Process(const uint8_t * next_in,size_t avail_in,size_t box_pos,uint8_t ** next_out,size_t * avail_out)33 JxlDecoderStatus JxlBoxContentDecoder::Process(const uint8_t* next_in,
34 size_t avail_in, size_t box_pos,
35 uint8_t** next_out,
36 size_t* avail_out) {
37 next_in += pos_ - box_pos;
38 avail_in -= pos_ - box_pos;
39
40 if (brob_decode_) {
41 if (!header_done_) {
42 if (avail_in < 4) return JXL_DEC_NEED_MORE_INPUT;
43 if (!box_until_eof_) {
44 if (remaining_ < 4) return JXL_DEC_ERROR;
45 remaining_ -= 4;
46 }
47 next_in += 4;
48 avail_in -= 4;
49 pos_ += 4;
50 header_done_ = true;
51 }
52
53 if (!brotli_dec) {
54 brotli_dec = BrotliDecoderCreateInstance(nullptr, nullptr, nullptr);
55 }
56
57 const uint8_t* next_in_before = next_in;
58 uint8_t* next_out_before = *next_out;
59 msan::MemoryIsInitialized(next_in, avail_in);
60 BrotliDecoderResult res = BrotliDecoderDecompressStream(
61 brotli_dec, &avail_in, &next_in, avail_out, next_out, nullptr);
62 size_t consumed = next_in - next_in_before;
63 size_t produced = *next_out - next_out_before;
64 if (res == BROTLI_DECODER_RESULT_ERROR) {
65 return JXL_DEC_ERROR;
66 }
67 msan::UnpoisonMemory(next_out_before, produced);
68 pos_ += consumed;
69 if (!box_until_eof_) remaining_ -= consumed;
70 if (res == BROTLI_DECODER_RESULT_NEEDS_MORE_INPUT) {
71 return JXL_DEC_NEED_MORE_INPUT;
72 }
73 if (res == BROTLI_DECODER_RESULT_NEEDS_MORE_OUTPUT) {
74 return JXL_DEC_BOX_NEED_MORE_OUTPUT;
75 }
76 if (res == BROTLI_DECODER_RESULT_SUCCESS) {
77 return JXL_DEC_SUCCESS;
78 }
79 // unknown Brotli result
80 return JXL_DEC_ERROR;
81 } else {
82 // remaining box bytes as seen from dec->file_pos
83 size_t can_read = avail_in;
84 if (!box_until_eof_) can_read = std::min<size_t>(can_read, remaining_);
85 size_t to_write = std::min<size_t>(can_read, *avail_out);
86 memcpy(*next_out, next_in, to_write);
87
88 *next_out += to_write;
89 *avail_out -= to_write;
90 if (!box_until_eof_) remaining_ -= to_write;
91 pos_ += to_write;
92
93 if (to_write < can_read) return JXL_DEC_BOX_NEED_MORE_OUTPUT;
94
95 if (!box_until_eof_ && remaining_ > 0) return JXL_DEC_NEED_MORE_INPUT;
96
97 return JXL_DEC_SUCCESS;
98 }
99 }
100
101 } // namespace jxl
102