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Initial implementation of trellis quantization

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A new pass type trellis_pass is added. It defines a pass where trellis
quantization is done in the quantize_trellis() function.
Trellis quantization can be enabled by setting use_moz_defaults to 2 or
by using the -trellis option in cjpeg
Note that trellis does currently not work with scan optimization. Scan
optimization is disabled when trellis is enabled.
This commit is contained in:
Frank Bossen
2014-03-23 21:06:01 +01:00
parent febf3466d4
commit d200b2c144
8 changed files with 331 additions and 17 deletions
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130
jccoefct.c
View File

@@ -2,6 +2,8 @@
* jccoefct.c
*
* Copyright (C) 1994-1997, Thomas G. Lane.
* mozjpeg Modifications:
* Copyright (C) 2014, Mozilla Corporation.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
@@ -13,7 +15,7 @@
#define JPEG_INTERNALS
#include "jinclude.h"
#include "jpeglib.h"
#include "jchuff.h"
/* We use a full-image coefficient buffer when doing Huffman optimization,
* and also for writing multiple-scan JPEG files. In all cases, the DCT
@@ -52,6 +54,10 @@ typedef struct {
/* In multi-pass modes, we need a virtual block array for each component. */
jvirt_barray_ptr whole_image[MAX_COMPONENTS];
/* when using trellis quantization, need to keep a copy of all unquantized coefficients */
jvirt_barray_ptr whole_image_uq[MAX_COMPONENTS];
} my_coef_controller;
typedef my_coef_controller * my_coef_ptr;
@@ -66,6 +72,8 @@ METHODDEF(boolean) compress_first_pass
METHODDEF(boolean) compress_output
JPP((j_compress_ptr cinfo, JSAMPIMAGE input_buf));
#endif
METHODDEF(boolean) compress_trellis_pass
JPP((j_compress_ptr cinfo, JSAMPIMAGE input_buf));
LOCAL(void)
@@ -122,6 +130,12 @@ start_pass_coef (j_compress_ptr cinfo, J_BUF_MODE pass_mode)
coef->pub.compress_data = compress_output;
break;
#endif
case JBUF_REQUANT:
if (coef->whole_image[0] == NULL)
ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
coef->pub.compress_data = compress_trellis_pass;
break;
default:
ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
break;
@@ -177,7 +191,7 @@ compress_data (j_compress_ptr cinfo, JSAMPIMAGE input_buf)
(*cinfo->fdct->forward_DCT) (cinfo, compptr,
input_buf[compptr->component_index],
coef->MCU_buffer[blkn],
ypos, xpos, (JDIMENSION) blockcnt);
ypos, xpos, (JDIMENSION) blockcnt, NULL);
if (blockcnt < compptr->MCU_width) {
/* Create some dummy blocks at the right edge of the image. */
jzero_far((void FAR *) coef->MCU_buffer[blkn + blockcnt],
@@ -252,6 +266,7 @@ compress_first_pass (j_compress_ptr cinfo, JSAMPIMAGE input_buf)
jpeg_component_info *compptr;
JBLOCKARRAY buffer;
JBLOCKROW thisblockrow, lastblockrow;
JBLOCKARRAY buffer_dst;
for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
ci++, compptr++) {
@@ -260,6 +275,12 @@ compress_first_pass (j_compress_ptr cinfo, JSAMPIMAGE input_buf)
((j_common_ptr) cinfo, coef->whole_image[ci],
coef->iMCU_row_num * compptr->v_samp_factor,
(JDIMENSION) compptr->v_samp_factor, TRUE);
buffer_dst = (*cinfo->mem->access_virt_barray)
((j_common_ptr) cinfo, coef->whole_image_uq[ci],
coef->iMCU_row_num * compptr->v_samp_factor,
(JDIMENSION) compptr->v_samp_factor, TRUE);
/* Count non-dummy DCT block rows in this iMCU row. */
if (coef->iMCU_row_num < last_iMCU_row)
block_rows = compptr->v_samp_factor;
@@ -282,7 +303,7 @@ compress_first_pass (j_compress_ptr cinfo, JSAMPIMAGE input_buf)
(*cinfo->fdct->forward_DCT) (cinfo, compptr,
input_buf[ci], thisblockrow,
(JDIMENSION) (block_row * DCTSIZE),
(JDIMENSION) 0, blocks_across);
(JDIMENSION) 0, blocks_across, buffer_dst[block_row]);
if (ndummy > 0) {
/* Create dummy blocks at the right edge of the image. */
thisblockrow += blocks_across; /* => first dummy block */
@@ -326,6 +347,100 @@ compress_first_pass (j_compress_ptr cinfo, JSAMPIMAGE input_buf)
return compress_output(cinfo, input_buf);
}
METHODDEF(boolean)
compress_trellis_pass (j_compress_ptr cinfo, JSAMPIMAGE input_buf)
{
my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;
JDIMENSION blocks_across, MCUs_across, MCUindex;
int bi, ci, h_samp_factor, block_row, block_rows, ndummy;
JCOEF lastDC;
jpeg_component_info *compptr;
JBLOCKARRAY buffer;
JBLOCKROW thisblockrow, lastblockrow;
JBLOCKARRAY buffer_dst;
for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
ci++, compptr++) {
c_derived_tbl actbl_data;
c_derived_tbl *actbl = &actbl_data;
jpeg_make_c_derived_tbl(cinfo, FALSE, cinfo->comp_info[ci].ac_tbl_no, &actbl);
/* Align the virtual buffer for this component. */
buffer = (*cinfo->mem->access_virt_barray)
((j_common_ptr) cinfo, coef->whole_image[ci],
coef->iMCU_row_num * compptr->v_samp_factor,
(JDIMENSION) compptr->v_samp_factor, TRUE);
buffer_dst = (*cinfo->mem->access_virt_barray)
((j_common_ptr) cinfo, coef->whole_image_uq[ci],
coef->iMCU_row_num * compptr->v_samp_factor,
(JDIMENSION) compptr->v_samp_factor, TRUE);
/* Count non-dummy DCT block rows in this iMCU row. */
if (coef->iMCU_row_num < last_iMCU_row)
block_rows = compptr->v_samp_factor;
else {
/* NB: can't use last_row_height here, since may not be set! */
block_rows = (int) (compptr->height_in_blocks % compptr->v_samp_factor);
if (block_rows == 0) block_rows = compptr->v_samp_factor;
}
blocks_across = compptr->width_in_blocks;
h_samp_factor = compptr->h_samp_factor;
/* Count number of dummy blocks to be added at the right margin. */
ndummy = (int) (blocks_across % h_samp_factor);
if (ndummy > 0)
ndummy = h_samp_factor - ndummy;
/* Perform DCT for all non-dummy blocks in this iMCU row. Each call
* on forward_DCT processes a complete horizontal row of DCT blocks.
*/
for (block_row = 0; block_row < block_rows; block_row++) {
thisblockrow = buffer[block_row];
quantize_trellis(cinfo, actbl, thisblockrow, buffer_dst[block_row], blocks_across, cinfo->quant_tbl_ptrs[cinfo->comp_info[ci].quant_tbl_no]);
if (ndummy > 0) {
/* Create dummy blocks at the right edge of the image. */
thisblockrow += blocks_across; /* => first dummy block */
jzero_far((void FAR *) thisblockrow, ndummy * SIZEOF(JBLOCK));
lastDC = thisblockrow[-1][0];
for (bi = 0; bi < ndummy; bi++) {
thisblockrow[bi][0] = lastDC;
}
}
}
/* If at end of image, create dummy block rows as needed.
* The tricky part here is that within each MCU, we want the DC values
* of the dummy blocks to match the last real block's DC value.
* This squeezes a few more bytes out of the resulting file...
*/
if (coef->iMCU_row_num == last_iMCU_row) {
blocks_across += ndummy; /* include lower right corner */
MCUs_across = blocks_across / h_samp_factor;
for (block_row = block_rows; block_row < compptr->v_samp_factor;
block_row++) {
thisblockrow = buffer[block_row];
lastblockrow = buffer[block_row-1];
jzero_far((void FAR *) thisblockrow,
(size_t) (blocks_across * SIZEOF(JBLOCK)));
for (MCUindex = 0; MCUindex < MCUs_across; MCUindex++) {
lastDC = lastblockrow[h_samp_factor-1][0];
for (bi = 0; bi < h_samp_factor; bi++) {
thisblockrow[bi][0] = lastDC;
}
thisblockrow += h_samp_factor; /* advance to next MCU in row */
lastblockrow += h_samp_factor;
}
}
}
}
/* NB: compress_output will increment iMCU_row_num if successful.
* A suspension return will result in redoing all the work above next time.
*/
/* Emit data to the entropy encoder, sharing code with subsequent passes */
return compress_output(cinfo, input_buf);
}
/*
* Process some data in subsequent passes of a multi-pass case.
@@ -377,6 +492,7 @@ compress_output (j_compress_ptr cinfo, JSAMPIMAGE input_buf)
}
}
}
/* Try to write the MCU. */
if (! (*cinfo->entropy->encode_mcu) (cinfo, coef->MCU_buffer)) {
/* Suspension forced; update state counters and exit */
@@ -429,6 +545,14 @@ jinit_c_coef_controller (j_compress_ptr cinfo, boolean need_full_buffer)
(JDIMENSION) jround_up((long) compptr->height_in_blocks,
(long) compptr->v_samp_factor),
(JDIMENSION) compptr->v_samp_factor);
coef->whole_image_uq[ci] = (*cinfo->mem->request_virt_barray)
((j_common_ptr) cinfo, JPOOL_IMAGE, FALSE,
(JDIMENSION) jround_up((long) compptr->width_in_blocks,
(long) compptr->h_samp_factor),
(JDIMENSION) jround_up((long) compptr->height_in_blocks,
(long) compptr->v_samp_factor),
(JDIMENSION) compptr->v_samp_factor);
}
#else
ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);