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{.byaddr.} 2% speed up.

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treeform 2022-05-07 11:44:46 -07:00
parent 9c9645598e
commit a2b6540f89
1 changed files with 5 additions and 4 deletions
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9
src/pixie/fileformats/jpeg.nim
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@ -1,4 +1,4 @@
import pixie/common, pixie/images, pixie/masks, sequtils, strutils, chroma import pixie/common, pixie/images, pixie/masks, sequtils, strutils, chroma, std/decls
# This JPEG decoder is loosely based on stb_image which is public domain. # This JPEG decoder is loosely based on stb_image which is public domain.
@ -658,6 +658,7 @@ proc decodeProgressiveContinuationBlock(
break break
template idct1D(s0, s1, s2, s3, s4, s5, s6, s7: int32) = template idct1D(s0, s1, s2, s3, s4, s5, s6, s7: int32) =
## Inverse discrete cosine transform 1D
template f2f(x: float32): int32 = (x * 4096 + 0.5).int32 template f2f(x: float32): int32 = (x * 4096 + 0.5).int32
template fsh(x: int32): int32 = x * 4096 template fsh(x: int32): int32 = x * 4096
p2 = s2 p2 = s2
@ -696,6 +697,7 @@ template idct1D(s0, s1, s2, s3, s4, s5, s6, s7: int32) =
t0 += p1 + p3 t0 += p1 + p3
proc idctBlock(component: var Component, offset: int, data: array[64, int16]) = proc idctBlock(component: var Component, offset: int, data: array[64, int16]) =
## Inverse discrete cosine transform whole block.
var values: array[64, int32] var values: array[64, int32]
for i in 0 ..< 8: for i in 0 ..< 8:
if data[i + 8] == 0 and if data[i + 8] == 0 and
@ -772,7 +774,7 @@ proc idctBlock(component: var Component, offset: int, data: array[64, int16]) =
proc decodeBlock(state: var DecoderState, comp, row, column: int) = proc decodeBlock(state: var DecoderState, comp, row, column: int) =
## Decodes a block. ## Decodes a block.
var data = state.components[comp].blocks[row][column] var data {.byaddr.} = state.components[comp].blocks[row][column]
if state.progressive: if state.progressive:
if state.spectralStart == 0: if state.spectralStart == 0:
state.decodeProgressiveBlock(comp, data) state.decodeProgressiveBlock(comp, data)
@ -780,9 +782,9 @@ proc decodeBlock(state: var DecoderState, comp, row, column: int) =
state.decodeProgressiveContinuationBlock(comp, data) state.decodeProgressiveContinuationBlock(comp, data)
else: else:
state.decodeRegularBlock(comp, data) state.decodeRegularBlock(comp, data)
state.components[comp].blocks[row][column] = data
template checkReset(state: var DecoderState) = template checkReset(state: var DecoderState) =
## Check if we might have run into a reset marker, then deal with it.
dec state.todo dec state.todo
if state.todo <= 0: if state.todo <= 0:
if state.bitCount < 24: if state.bitCount < 24:
@ -793,7 +795,6 @@ template checkReset(state: var DecoderState) =
state.pos += 2 state.pos += 2
else: else:
failInvalid("did not get expected reset marker") failInvalid("did not get expected reset marker")
state.reset() state.reset()
proc decodeBlocks(state: var DecoderState) = proc decodeBlocks(state: var DecoderState) =