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Use 5x5 win & 9 AC coeffs when smoothing DC scans

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... of progressive images.

Based on:
be8d36d13b
9d528f278e
85f36f0765
63a4d39e38
51336a6ad5

Closes #459
Closes #474
This commit is contained in:
DRC
2020-10-05 13:37:44 +02:00
parent d523435e18
commit 6d91e950c8
5 changed files with 240 additions and 65 deletions
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25
ChangeLog.md
View File

@@ -50,16 +50,21 @@ and AMD CPUs, as well as a measured average overall compression speedup of
0-23% on platforms that do not have a SIMD-accelerated Huffman encoding
implementation.
6. When decompressing progressive Huffman-encoded JPEG images, the block
smoothing algorithm that the libjpeg API library optionally applies is now more
fault-tolerant. Previously, if a particular scan was incomplete, then the
smoothing parameters for the incomplete scan would be applied to the entire
output image, including the parts of the image that were generated by the prior
(complete) scan. Visually, this had the effect of removing block smoothing
from lower-frequency scans if they were followed by an incomplete
higher-frequency scan. libjpeg-turbo now applies block smoothing parameters to
each iMCU row based on which scan generated the pixels in that row, rather than
always using the block smoothing parameters for the most recent scan.
6. The block smoothing algorithm that is applied by default when decompressing
progressive Huffman-encoded JPEG images has been improved in the following
ways:
- The algorithm is now more fault-tolerant. Previously, if a particular
scan was incomplete, then the smoothing parameters for the incomplete scan
would be applied to the entire output image, including the parts of the image
that were generated by the prior (complete) scan. Visually, this had the
effect of removing block smoothing from lower-frequency scans if they were
followed by an incomplete higher-frequency scan. libjpeg-turbo now applies
block smoothing parameters to each iMCU row based on which scan generated the
pixels in that row, rather than always using the block smoothing parameters for
the most recent scan.
- When applying block smoothing to DC scans, a Gaussian-like kernel with a
5x5 window is used to reduce the "blocky" appearance.
7. Added SIMD acceleration for progressive Huffman encoding on Arm platforms.
This speeds up the compression of full-color progressive JPEGs by about 30-40%

8
jdarith.c
View File

@@ -4,7 +4,7 @@
* This file was part of the Independent JPEG Group's software:
* Developed 1997-2015 by Guido Vollbeding.
* libjpeg-turbo Modifications:
* Copyright (C) 2015-2019, D. R. Commander.
* Copyright (C) 2015-2020, D. R. Commander.
* For conditions of distribution and use, see the accompanying README.ijg
* file.
*
@@ -669,12 +669,14 @@ bad:
&cinfo->coef_bits[cindex + cinfo->num_components][0];
if (cinfo->Ss && coef_bit_ptr[0] < 0) /* AC without prior DC scan */
WARNMS2(cinfo, JWRN_BOGUS_PROGRESSION, cindex, 0);
for (coefi = MIN(cinfo->Ss, 1); coefi <= MAX(cinfo->Se, 9); coefi++) {
if (cinfo->input_scan_number > 1)
prev_coef_bit_ptr[coefi] = coef_bit_ptr[coefi];
}
for (coefi = cinfo->Ss; coefi <= cinfo->Se; coefi++) {
int expected = (coef_bit_ptr[coefi] < 0) ? 0 : coef_bit_ptr[coefi];
if (cinfo->Ah != expected)
WARNMS2(cinfo, JWRN_BOGUS_PROGRESSION, cindex, coefi);
if (cinfo->input_scan_number > 1)
prev_coef_bit_ptr[coefi] = coef_bit_ptr[coefi];
coef_bit_ptr[coefi] = cinfo->Al;
}
}

261
jdcoefct.c
View File

@@ -5,7 +5,7 @@
* Copyright (C) 1994-1997, Thomas G. Lane.
* libjpeg-turbo Modifications:
* Copyright 2009 Pierre Ossman <ossman@cendio.se> for Cendio AB
* Copyright (C) 2010, 2015-2016, 2019, D. R. Commander.
* Copyright (C) 2010, 2015-2016, 2019-2020, D. R. Commander.
* Copyright (C) 2015, 2020, Google, Inc.
* For conditions of distribution and use, see the accompanying README.ijg
* file.
@@ -330,19 +330,22 @@ decompress_data(j_decompress_ptr cinfo, JSAMPIMAGE output_buf)
#ifdef BLOCK_SMOOTHING_SUPPORTED
/*
* This code applies interblock smoothing as described by section K.8
* of the JPEG standard: the first 5 AC coefficients are estimated from
* the DC values of a DCT block and its 8 neighboring blocks.
* This code applies interblock smoothing; the first 9 AC coefficients are
* estimated from the DC values of a DCT block and its 24 neighboring blocks.
* We apply smoothing only for progressive JPEG decoding, and only if
* the coefficients it can estimate are not yet known to full precision.
*/
/* Natural-order array positions of the first 5 zigzag-order coefficients */
/* Natural-order array positions of the first 9 zigzag-order coefficients */
#define Q01_POS 1
#define Q10_POS 8
#define Q20_POS 16
#define Q11_POS 9
#define Q02_POS 2
#define Q03_POS 3
#define Q12_POS 10
#define Q21_POS 17
#define Q30_POS 24
/*
* Determine whether block smoothing is applicable and safe.
@@ -381,21 +384,26 @@ smoothing_ok(j_decompress_ptr cinfo)
/* All components' quantization values must already be latched. */
if ((qtable = compptr->quant_table) == NULL)
return FALSE;
/* Verify DC & first 5 AC quantizers are nonzero to avoid zero-divide. */
/* Verify DC & first 9 AC quantizers are nonzero to avoid zero-divide. */
if (qtable->quantval[0] == 0 ||
qtable->quantval[Q01_POS] == 0 ||
qtable->quantval[Q10_POS] == 0 ||
qtable->quantval[Q20_POS] == 0 ||
qtable->quantval[Q11_POS] == 0 ||
qtable->quantval[Q02_POS] == 0)
qtable->quantval[Q02_POS] == 0 ||
qtable->quantval[Q03_POS] == 0 ||
qtable->quantval[Q12_POS] == 0 ||
qtable->quantval[Q21_POS] == 0 ||
qtable->quantval[Q30_POS] == 0)
return FALSE;
/* DC values must be at least partly known for all components. */
coef_bits = cinfo->coef_bits[ci];
prev_coef_bits = cinfo->coef_bits[ci + cinfo->num_components];
if (coef_bits[0] < 0)
return FALSE;
coef_bits_latch[0] = coef_bits[0];
/* Block smoothing is helpful if some AC coefficients remain inaccurate. */
for (coefi = 1; coefi <= 5; coefi++) {
for (coefi = 1; coefi < SAVED_COEFS; coefi++) {
if (cinfo->input_scan_number > 1)
prev_coef_bits_latch[coefi] = prev_coef_bits[coefi];
coef_bits_latch[coefi] = coef_bits[coefi];
@@ -422,17 +430,20 @@ decompress_smooth_data(j_decompress_ptr cinfo, JSAMPIMAGE output_buf)
JDIMENSION block_num, last_block_column;
int ci, block_row, block_rows, access_rows;
JBLOCKARRAY buffer;
JBLOCKROW buffer_ptr, prev_block_row, next_block_row;
JBLOCKROW buffer_ptr, prev_prev_block_row, prev_block_row;
JBLOCKROW next_block_row, next_next_block_row;
JSAMPARRAY output_ptr;
JDIMENSION output_col;
jpeg_component_info *compptr;
inverse_DCT_method_ptr inverse_DCT;
boolean first_row, last_row;
boolean change_dc;
JCOEF *workspace;
int *coef_bits;
JQUANT_TBL *quanttbl;
JLONG Q00, Q01, Q02, Q10, Q11, Q20, num;
int DC1, DC2, DC3, DC4, DC5, DC6, DC7, DC8, DC9;
JLONG Q00, Q01, Q02, Q03 = 0, Q10, Q11, Q12 = 0, Q20, Q21 = 0, Q30 = 0, num;
int DC01, DC02, DC03, DC04, DC05, DC06, DC07, DC08, DC09, DC10, DC11, DC12,
DC13, DC14, DC15, DC16, DC17, DC18, DC19, DC20, DC21, DC22, DC23, DC24,
DC25;
int Al, pred;
/* Keep a local variable to avoid looking it up more than once */
@@ -444,10 +455,10 @@ decompress_smooth_data(j_decompress_ptr cinfo, JSAMPIMAGE output_buf)
if (cinfo->input_scan_number == cinfo->output_scan_number) {
/* If input is working on current scan, we ordinarily want it to
* have completed the current row. But if input scan is DC,
* we want it to keep one row ahead so that next block row's DC
* we want it to keep two rows ahead so that next two block rows' DC
* values are up to date.
*/
JDIMENSION delta = (cinfo->Ss == 0) ? 1 : 0;
JDIMENSION delta = (cinfo->Ss == 0) ? 2 : 0;
if (cinfo->input_iMCU_row > cinfo->output_iMCU_row + delta)
break;
}
@@ -462,31 +473,36 @@ decompress_smooth_data(j_decompress_ptr cinfo, JSAMPIMAGE output_buf)
if (!compptr->component_needed)
continue;
/* Count non-dummy DCT block rows in this iMCU row. */
if (cinfo->output_iMCU_row < last_iMCU_row) {
if (cinfo->output_iMCU_row < last_iMCU_row - 1) {
block_rows = compptr->v_samp_factor;
access_rows = block_rows * 3; /* this and next two iMCU rows */
} else if (cinfo->output_iMCU_row < last_iMCU_row) {
block_rows = compptr->v_samp_factor;
access_rows = block_rows * 2; /* this and next iMCU row */
last_row = FALSE;
} else {
/* NB: can't use last_row_height here; it is input-side-dependent! */
block_rows = (int)(compptr->height_in_blocks % compptr->v_samp_factor);
if (block_rows == 0) block_rows = compptr->v_samp_factor;
access_rows = block_rows; /* this iMCU row only */
last_row = TRUE;
}
/* Align the virtual buffer for this component. */
if (cinfo->output_iMCU_row > 0) {
access_rows += compptr->v_samp_factor; /* prior iMCU row too */
if (cinfo->output_iMCU_row > 1) {
access_rows += 2 * compptr->v_samp_factor; /* prior two iMCU rows too */
buffer = (*cinfo->mem->access_virt_barray)
((j_common_ptr)cinfo, coef->whole_image[ci],
(cinfo->output_iMCU_row - 2) * compptr->v_samp_factor,
(JDIMENSION)access_rows, FALSE);
buffer += 2 * compptr->v_samp_factor; /* point to current iMCU row */
} else if (cinfo->output_iMCU_row > 0) {
buffer = (*cinfo->mem->access_virt_barray)
((j_common_ptr)cinfo, coef->whole_image[ci],
(cinfo->output_iMCU_row - 1) * compptr->v_samp_factor,
(JDIMENSION)access_rows, FALSE);
buffer += compptr->v_samp_factor; /* point to current iMCU row */
first_row = FALSE;
} else {
buffer = (*cinfo->mem->access_virt_barray)
((j_common_ptr)cinfo, coef->whole_image[ci],
(JDIMENSION)0, (JDIMENSION)access_rows, FALSE);
first_row = TRUE;
}
/* Fetch component-dependent info.
* If the current scan is incomplete, then we use the component-dependent
@@ -497,6 +513,13 @@ decompress_smooth_data(j_decompress_ptr cinfo, JSAMPIMAGE output_buf)
coef->coef_bits_latch + ((ci + cinfo->num_components) * SAVED_COEFS);
else
coef_bits = coef->coef_bits_latch + (ci * SAVED_COEFS);
/* We only do DC interpolation if no AC coefficient data is available. */
change_dc =
coef_bits[1] == -1 && coef_bits[2] == -1 && coef_bits[3] == -1 &&
coef_bits[4] == -1 && coef_bits[5] == -1 && coef_bits[6] == -1 &&
coef_bits[7] == -1 && coef_bits[8] == -1 && coef_bits[9] == -1;
quanttbl = compptr->quant_table;
Q00 = quanttbl->quantval[0];
Q01 = quanttbl->quantval[Q01_POS];
@@ -504,27 +527,51 @@ decompress_smooth_data(j_decompress_ptr cinfo, JSAMPIMAGE output_buf)
Q20 = quanttbl->quantval[Q20_POS];
Q11 = quanttbl->quantval[Q11_POS];
Q02 = quanttbl->quantval[Q02_POS];
if (change_dc) {
Q03 = quanttbl->quantval[Q03_POS];
Q12 = quanttbl->quantval[Q12_POS];
Q21 = quanttbl->quantval[Q21_POS];
Q30 = quanttbl->quantval[Q30_POS];
}
inverse_DCT = cinfo->idct->inverse_DCT[ci];
output_ptr = output_buf[ci];
/* Loop over all DCT blocks to be processed. */
for (block_row = 0; block_row < block_rows; block_row++) {
buffer_ptr = buffer[block_row] + cinfo->master->first_MCU_col[ci];
if (first_row && block_row == 0)
if (block_row > 0 || cinfo->output_iMCU_row > 0)
prev_block_row =
buffer[block_row - 1] + cinfo->master->first_MCU_col[ci];
else
prev_block_row = buffer_ptr;
if (block_row > 1 || cinfo->output_iMCU_row > 1)
prev_prev_block_row =
buffer[block_row - 2] + cinfo->master->first_MCU_col[ci];
else
prev_prev_block_row = prev_block_row;
if (block_row < block_rows - 1 || cinfo->output_iMCU_row < last_iMCU_row)
next_block_row =
buffer[block_row + 1] + cinfo->master->first_MCU_col[ci];
else
prev_block_row = buffer[block_row - 1] +
cinfo->master->first_MCU_col[ci];
if (last_row && block_row == block_rows - 1)
next_block_row = buffer_ptr;
if (block_row < block_rows - 2 ||
cinfo->output_iMCU_row < last_iMCU_row - 1)
next_next_block_row =
buffer[block_row + 2] + cinfo->master->first_MCU_col[ci];
else
next_block_row = buffer[block_row + 1] +
cinfo->master->first_MCU_col[ci];
next_next_block_row = next_block_row;
/* We fetch the surrounding DC values using a sliding-register approach.
* Initialize all nine here so as to do the right thing on narrow pics.
* Initialize all 25 here so as to do the right thing on narrow pics.
*/
DC1 = DC2 = DC3 = (int)prev_block_row[0][0];
DC4 = DC5 = DC6 = (int)buffer_ptr[0][0];
DC7 = DC8 = DC9 = (int)next_block_row[0][0];
DC01 = DC02 = DC03 = DC04 = DC05 = (int)prev_prev_block_row[0][0];
DC06 = DC07 = DC08 = DC09 = DC10 = (int)prev_block_row[0][0];
DC11 = DC12 = DC13 = DC14 = DC15 = (int)buffer_ptr[0][0];
DC16 = DC17 = DC18 = DC19 = DC20 = (int)next_block_row[0][0];
DC21 = DC22 = DC23 = DC24 = DC25 = (int)next_next_block_row[0][0];
output_col = 0;
last_block_column = compptr->width_in_blocks - 1;
for (block_num = cinfo->master->first_MCU_col[ci];
@@ -532,18 +579,39 @@ decompress_smooth_data(j_decompress_ptr cinfo, JSAMPIMAGE output_buf)
/* Fetch current DCT block into workspace so we can modify it. */
jcopy_block_row(buffer_ptr, (JBLOCKROW)workspace, (JDIMENSION)1);
/* Update DC values */
if (block_num < last_block_column) {
DC3 = (int)prev_block_row[1][0];
DC6 = (int)buffer_ptr[1][0];
DC9 = (int)next_block_row[1][0];
if (block_num == cinfo->master->first_MCU_col[ci] &&
block_num < last_block_column) {
DC04 = (int)prev_prev_block_row[1][0];
DC09 = (int)prev_block_row[1][0];
DC14 = (int)buffer_ptr[1][0];
DC19 = (int)next_block_row[1][0];
DC24 = (int)next_next_block_row[1][0];
}
/* Compute coefficient estimates per K.8.
* An estimate is applied only if coefficient is still zero,
* and is not known to be fully accurate.
if (block_num < last_block_column - 1) {
DC05 = (int)prev_prev_block_row[2][0];
DC10 = (int)prev_block_row[2][0];
DC15 = (int)buffer_ptr[2][0];
DC20 = (int)next_block_row[2][0];
DC25 = (int)next_next_block_row[2][0];
}
/* If DC interpolation is enabled, compute coefficient estimates using
* a Gaussian-like kernel, keeping the averages of the DC values.
*
* If DC interpolation is disabled, compute coefficient estimates using
* an algorithm similar to the one described in Section K.8 of the JPEG
* standard, except applied to a 5x5 window rather than a 3x3 window.
*
* An estimate is applied only if the coefficient is still zero and is
* not known to be fully accurate.
*/
/* AC01 */
if ((Al = coef_bits[1]) != 0 && workspace[1] == 0) {
num = 36 * Q00 * (DC4 - DC6);
num = Q00 * (change_dc ?
(-DC01 - DC02 + DC04 + DC05 - 3 * DC06 + 13 * DC07 -
13 * DC09 + 3 * DC10 - 3 * DC11 + 38 * DC12 - 38 * DC14 +
3 * DC15 - 3 * DC16 + 13 * DC17 - 13 * DC19 + 3 * DC20 -
DC21 - DC22 + DC24 + DC25) :
(-7 * DC11 + 50 * DC12 - 50 * DC14 + 7 * DC15));
if (num >= 0) {
pred = (int)(((Q01 << 7) + num) / (Q01 << 8));
if (Al > 0 && pred >= (1 << Al))
@@ -558,7 +626,12 @@ decompress_smooth_data(j_decompress_ptr cinfo, JSAMPIMAGE output_buf)
}
/* AC10 */
if ((Al = coef_bits[2]) != 0 && workspace[8] == 0) {
num = 36 * Q00 * (DC2 - DC8);
num = Q00 * (change_dc ?
(-DC01 - 3 * DC02 - 3 * DC03 - 3 * DC04 - DC05 - DC06 +
13 * DC07 + 38 * DC08 + 13 * DC09 - DC10 + DC16 -
13 * DC17 - 38 * DC18 - 13 * DC19 + DC20 + DC21 +
3 * DC22 + 3 * DC23 + 3 * DC24 + DC25) :
(-7 * DC03 + 50 * DC08 - 50 * DC18 + 7 * DC23));
if (num >= 0) {
pred = (int)(((Q10 << 7) + num) / (Q10 << 8));
if (Al > 0 && pred >= (1 << Al))
@@ -573,7 +646,10 @@ decompress_smooth_data(j_decompress_ptr cinfo, JSAMPIMAGE output_buf)
}
/* AC20 */
if ((Al = coef_bits[3]) != 0 && workspace[16] == 0) {
num = 9 * Q00 * (DC2 + DC8 - 2 * DC5);
num = Q00 * (change_dc ?
(DC03 + 2 * DC07 + 7 * DC08 + 2 * DC09 - 5 * DC12 - 14 * DC13 -
5 * DC14 + 2 * DC17 + 7 * DC18 + 2 * DC19 + DC23) :
(-DC03 + 13 * DC08 - 24 * DC13 + 13 * DC18 - DC23));
if (num >= 0) {
pred = (int)(((Q20 << 7) + num) / (Q20 << 8));
if (Al > 0 && pred >= (1 << Al))
@@ -588,7 +664,11 @@ decompress_smooth_data(j_decompress_ptr cinfo, JSAMPIMAGE output_buf)
}
/* AC11 */
if ((Al = coef_bits[4]) != 0 && workspace[9] == 0) {
num = 5 * Q00 * (DC1 - DC3 - DC7 + DC9);
num = Q00 * (change_dc ?
(-DC01 + DC05 + 9 * DC07 - 9 * DC09 - 9 * DC17 +
9 * DC19 + DC21 - DC25) :
(DC10 + DC16 - 10 * DC17 + 10 * DC19 - DC02 - DC20 + DC22 -
DC24 + DC04 - DC06 + 10 * DC07 - 10 * DC09));
if (num >= 0) {
pred = (int)(((Q11 << 7) + num) / (Q11 << 8));
if (Al > 0 && pred >= (1 << Al))
@@ -603,7 +683,10 @@ decompress_smooth_data(j_decompress_ptr cinfo, JSAMPIMAGE output_buf)
}
/* AC02 */
if ((Al = coef_bits[5]) != 0 && workspace[2] == 0) {
num = 9 * Q00 * (DC4 + DC6 - 2 * DC5);
num = Q00 * (change_dc ?
(2 * DC07 - 5 * DC08 + 2 * DC09 + DC11 + 7 * DC12 - 14 * DC13 +
7 * DC14 + DC15 + 2 * DC17 - 5 * DC18 + 2 * DC19) :
(-DC11 + 13 * DC12 - 24 * DC13 + 13 * DC14 - DC15));
if (num >= 0) {
pred = (int)(((Q02 << 7) + num) / (Q02 << 8));
if (Al > 0 && pred >= (1 << Al))
@@ -616,14 +699,96 @@ decompress_smooth_data(j_decompress_ptr cinfo, JSAMPIMAGE output_buf)
}
workspace[2] = (JCOEF)pred;
}
if (change_dc) {
/* AC03 */
if ((Al = coef_bits[6]) != 0 && workspace[3] == 0) {
num = Q00 * (DC07 - DC09 + 2 * DC12 - 2 * DC14 + DC17 - DC19);
if (num >= 0) {
pred = (int)(((Q03 << 7) + num) / (Q03 << 8));
if (Al > 0 && pred >= (1 << Al))
pred = (1 << Al) - 1;
} else {
pred = (int)(((Q03 << 7) - num) / (Q03 << 8));
if (Al > 0 && pred >= (1 << Al))
pred = (1 << Al) - 1;
pred = -pred;
}
workspace[3] = (JCOEF)pred;
}
/* AC12 */
if ((Al = coef_bits[7]) != 0 && workspace[10] == 0) {
num = Q00 * (DC07 - 3 * DC08 + DC09 - DC17 + 3 * DC18 - DC19);
if (num >= 0) {
pred = (int)(((Q12 << 7) + num) / (Q12 << 8));
if (Al > 0 && pred >= (1 << Al))
pred = (1 << Al) - 1;
} else {
pred = (int)(((Q12 << 7) - num) / (Q12 << 8));
if (Al > 0 && pred >= (1 << Al))
pred = (1 << Al) - 1;
pred = -pred;
}
workspace[10] = (JCOEF)pred;
}
/* AC21 */
if ((Al = coef_bits[8]) != 0 && workspace[17] == 0) {
num = Q00 * (DC07 - DC09 - 3 * DC12 + 3 * DC14 + DC17 - DC19);
if (num >= 0) {
pred = (int)(((Q21 << 7) + num) / (Q21 << 8));
if (Al > 0 && pred >= (1 << Al))
pred = (1 << Al) - 1;
} else {
pred = (int)(((Q21 << 7) - num) / (Q21 << 8));
if (Al > 0 && pred >= (1 << Al))
pred = (1 << Al) - 1;
pred = -pred;
}
workspace[17] = (JCOEF)pred;
}
/* AC30 */
if ((Al = coef_bits[9]) != 0 && workspace[24] == 0) {
num = Q00 * (DC07 + 2 * DC08 + DC09 - DC17 - 2 * DC18 - DC19);
if (num >= 0) {
pred = (int)(((Q30 << 7) + num) / (Q30 << 8));
if (Al > 0 && pred >= (1 << Al))
pred = (1 << Al) - 1;
} else {
pred = (int)(((Q30 << 7) - num) / (Q30 << 8));
if (Al > 0 && pred >= (1 << Al))
pred = (1 << Al) - 1;
pred = -pred;
}
workspace[24] = (JCOEF)pred;
}
/* coef_bits[0] is non-negative. Otherwise this function would not
* be called.
*/
num = Q00 *
(-2 * DC01 - 6 * DC02 - 8 * DC03 - 6 * DC04 - 2 * DC05 -
6 * DC06 + 6 * DC07 + 42 * DC08 + 6 * DC09 - 6 * DC10 -
8 * DC11 + 42 * DC12 + 152 * DC13 + 42 * DC14 - 8 * DC15 -
6 * DC16 + 6 * DC17 + 42 * DC18 + 6 * DC19 - 6 * DC20 -
2 * DC21 - 6 * DC22 - 8 * DC23 - 6 * DC24 - 2 * DC25);
if (num >= 0) {
pred = (int)(((Q00 << 7) + num) / (Q00 << 8));
} else {
pred = (int)(((Q00 << 7) - num) / (Q00 << 8));
pred = -pred;
}
workspace[0] = (JCOEF)pred;
} /* change_dc */
/* OK, do the IDCT */
(*inverse_DCT) (cinfo, compptr, (JCOEFPTR)workspace, output_ptr,
output_col);
/* Advance for next column */
DC1 = DC2; DC2 = DC3;
DC4 = DC5; DC5 = DC6;
DC7 = DC8; DC8 = DC9;
buffer_ptr++, prev_block_row++, next_block_row++;
DC01 = DC02; DC02 = DC03; DC03 = DC04; DC04 = DC05;
DC06 = DC07; DC07 = DC08; DC08 = DC09; DC09 = DC10;
DC11 = DC12; DC12 = DC13; DC13 = DC14; DC14 = DC15;
DC16 = DC17; DC17 = DC18; DC18 = DC19; DC19 = DC20;
DC21 = DC22; DC22 = DC23; DC23 = DC24; DC24 = DC25;
buffer_ptr++, prev_block_row++, next_block_row++,
prev_prev_block_row++, next_next_block_row++;
output_col += compptr->_DCT_scaled_size;
}
output_ptr += compptr->_DCT_scaled_size;
@@ -672,7 +837,7 @@ jinit_d_coef_controller(j_decompress_ptr cinfo, boolean need_full_buffer)
#ifdef BLOCK_SMOOTHING_SUPPORTED
/* If block smoothing could be used, need a bigger window */
if (cinfo->progressive_mode)
access_rows *= 3;
access_rows *= 5;
#endif
coef->whole_image[ci] = (*cinfo->mem->request_virt_barray)
((j_common_ptr)cinfo, JPOOL_IMAGE, TRUE,

3
jdcoefct.h
View File

@@ -5,6 +5,7 @@
* Copyright (C) 1994-1997, Thomas G. Lane.
* libjpeg-turbo Modifications:
* Copyright 2009 Pierre Ossman <ossman@cendio.se> for Cendio AB
* Copyright (C) 2020, Google, Inc.
* For conditions of distribution and use, see the accompanying README.ijg
* file.
*/
@@ -51,7 +52,7 @@ typedef struct {
#ifdef BLOCK_SMOOTHING_SUPPORTED
/* When doing block smoothing, we latch coefficient Al values here */
int *coef_bits_latch;
#define SAVED_COEFS 6 /* we save coef_bits[0..5] */
#define SAVED_COEFS 10 /* we save coef_bits[0..9] */
#endif
} my_coef_controller;

8
jdphuff.c
View File

@@ -4,7 +4,7 @@
* This file was part of the Independent JPEG Group's software:
* Copyright (C) 1995-1997, Thomas G. Lane.
* libjpeg-turbo Modifications:
* Copyright (C) 2015-2016, 2018-2019, D. R. Commander.
* Copyright (C) 2015-2016, 2018-2020, D. R. Commander.
* For conditions of distribution and use, see the accompanying README.ijg
* file.
*
@@ -127,12 +127,14 @@ start_pass_phuff_decoder(j_decompress_ptr cinfo)
prev_coef_bit_ptr = &cinfo->coef_bits[cindex + cinfo->num_components][0];
if (!is_DC_band && coef_bit_ptr[0] < 0) /* AC without prior DC scan */
WARNMS2(cinfo, JWRN_BOGUS_PROGRESSION, cindex, 0);
for (coefi = MIN(cinfo->Ss, 1); coefi <= MAX(cinfo->Se, 9); coefi++) {
if (cinfo->input_scan_number > 1)
prev_coef_bit_ptr[coefi] = coef_bit_ptr[coefi];
}
for (coefi = cinfo->Ss; coefi <= cinfo->Se; coefi++) {
int expected = (coef_bit_ptr[coefi] < 0) ? 0 : coef_bit_ptr[coefi];
if (cinfo->Ah != expected)
WARNMS2(cinfo, JWRN_BOGUS_PROGRESSION, cindex, coefi);
if (cinfo->input_scan_number > 1)
prev_coef_bit_ptr[coefi] = coef_bit_ptr[coefi];
coef_bit_ptr[coefi] = cinfo->Al;
}
}