MyouProject/pixie
3
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

getBit endian

Browse source
This commit is contained in:
Ryan Oldenburg 2022-05-25 22:09:07 -05:00
parent 11bd83b495
commit 7b1cd09cd3
1 changed files with 4 additions and 5 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

9
src/pixie/fileformats/jpeg.nim
View file

@ -529,10 +529,9 @@ proc getBit(state: var DecoderState): int =
## Get a single bit.
if state.bitsBuffered < 1:
state.fillBitBuffer()
let k = state.bitBuffer
result = ((state.bitBuffer and cast[uint32](0x80000000)) shr 31).int
state.bitBuffer = state.bitBuffer shl 1
dec state.bitsBuffered
return (k.int and 0x80000000.int)
proc getBitsAsSignedInt(state: var DecoderState, n: int): int =
## Get n number of bits as a signed integer.
@ -616,7 +615,7 @@ proc decodeProgressiveBlock(
state.components[component].dcPred = dc
data[0] = cast[int16](dc * (1 shl state.successiveApproxLow))
else:
if getBit(state) != 0:
if state.getBit() != 0:
data[0] = cast[int16](data[0] + (1 shl state.successiveApproxLow))
proc decodeProgressiveContinuationBlock(
@ -689,7 +688,7 @@ proc decodeProgressiveContinuationBlock(
else:
if s != 1:
failInvalid("bad huffman code")
if getBit(state) != 0:
if state.getBit() != 0:
s = bit.int
else:
s = -bit.int
@ -698,7 +697,7 @@ proc decodeProgressiveContinuationBlock(
let zig = deZigZag[k]
inc k
if data[zig] != 0:
if getBit(state) != 0:
if state.getBit() != 0:
if (data[zig] and bit) == 0:
if data[zig] > 0:
data[zig] = cast[int16](data[zig] + bit)