LibGfx/TIFF: Use LZWDecoder::decode_all()

This commit is contained in:
Lucas CHOLLET 2023-11-27 22:44:14 -05:00 committed by Andreas Kling
parent 2a5cb5becb
commit cc816b486c
Notes: sideshowbarker 2024-07-17 08:27:05 +09:00

View File

@ -115,40 +115,19 @@ private:
TRY(loop_over_pixels([this]() { return read_value<u8>(); }));
break;
case Compression::LZW: {
Vector<u8> result_buffer {};
Optional<Compress::LZWDecoder<BigEndianInputBitStream>> decoder {};
u16 clear_code {};
u16 end_of_information_code {};
ByteBuffer decoded_bytes {};
u32 read_head {};
auto initializer = [&](u32 bytes) -> ErrorOr<void> {
auto strip_stream = make<FixedMemoryStream>(TRY(m_stream->read_in_place<u8 const>(bytes)));
auto lzw_stream = make<BigEndianInputBitStream>(MaybeOwned<Stream>(move(strip_stream)));
decoder = Compress::LZWDecoder { MaybeOwned<BigEndianInputBitStream> { move(lzw_stream) }, 8, -1 };
clear_code = decoder->add_control_code();
end_of_information_code = decoder->add_control_code();
decoded_bytes = TRY(Compress::LZWDecoder<BigEndianInputBitStream>::decode_all(TRY(m_stream->read_in_place<u8 const>(bytes)), 8, -1));
read_head = 0;
return {};
};
auto read_lzw_byte = [&]() -> ErrorOr<u8> {
while (true) {
if (!result_buffer.is_empty())
return result_buffer.take_first();
auto const code = TRY(decoder->next_code());
if (code == clear_code) {
decoder->reset();
continue;
}
if (code == end_of_information_code)
return Error::from_string_literal("TIFFImageDecoderPlugin: Reached end of LZW stream");
result_buffer = decoder->get_output();
}
if (read_head < decoded_bytes.size())
return decoded_bytes[read_head++];
return Error::from_string_literal("TIFFImageDecoderPlugin: Reached end of LZW stream");
};
TRY(loop_over_pixels([read_lzw_byte = move(read_lzw_byte)]() { return read_lzw_byte(); }, move(initializer)));