Skip to content

Commit

Permalink
Implement pruning of search for best number of refinement layers
Browse files Browse the repository at this point in the history
  • Loading branch information
fbossen authored and fbossen committed Feb 19, 2014
1 parent 8d0816e commit c92da45
Show file tree
Hide file tree
Showing 2 changed files with 60 additions and 56 deletions.
91 changes: 46 additions & 45 deletions jcmaster.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -43,7 +43,7 @@ typedef struct {
/* fields for scan optimisation */
unsigned char * scan_buffer[64]; /* buffer for a given scan */
unsigned long scan_size[64]; /* size for a given scan */
unsigned long best_freq_split_cost; /* bit count for best frequency split */
unsigned long best_cost; /* bit count for best frequency split */
int best_freq_split_idx_luma; /* index for best frequency split (luma) */
int best_freq_split_idx_chroma; /* index for best frequency split (chroma) */
int best_Al_luma; /* best value for Al found in scan search (luma) */
Expand Down Expand Up @@ -600,38 +600,38 @@ select_scans (j_compress_ptr cinfo, int next_scan_number)
int luma_freq_split_scan_start = cinfo->num_scans_luma_dc + 3 * cinfo->Al_max_luma + 2;
int chroma_freq_split_scan_start = cinfo->num_scans_luma+cinfo->num_scans_chroma_dc+(6*cinfo->Al_max_chroma+4);

if (next_scan_number == luma_freq_split_scan_start) {
int Al;
int i;

master->best_Al_luma = 0;

for (Al = 0; Al <= cinfo->Al_max_luma; Al++) {
size[Al] = master->scan_size[1 + 2 * Al];
size[Al] += master->scan_size[2 + 2 * Al];

if (next_scan_number > 1 && next_scan_number <= luma_freq_split_scan_start) {
if ((next_scan_number - 1) % 3 == 2) {
int Al = (next_scan_number - 1) / 3;
int i;
unsigned long cost = 0;
cost += master->scan_size[next_scan_number-2];
cost += master->scan_size[next_scan_number-1];
for (i = 0; i < Al; i++)
size[Al] += master->scan_size[3 + 2*cinfo->Al_max_luma + i];
cost += master->scan_size[3 + 3*i];

if (Al == 0 || size[Al] < size[master->best_Al_luma])
if (Al == 0 || cost < master->best_cost) {
master->best_cost = cost;
master->best_Al_luma = Al;
else
break;
} else {
master->scan_number = luma_freq_split_scan_start - 1;
master->pass_number = 2 * master->scan_number + 1;
}
}

} else if (next_scan_number > luma_freq_split_scan_start && next_scan_number <= cinfo->num_scans_luma) {
if (next_scan_number == luma_freq_split_scan_start + 1) {
master->best_freq_split_idx_luma = 0;
master->best_freq_split_cost = master->scan_size[next_scan_number-1];
master->best_cost = master->scan_size[next_scan_number-1];

} else if ((next_scan_number - luma_freq_split_scan_start) % 2 == 1) {
int idx = (next_scan_number - luma_freq_split_scan_start) >> 1;
unsigned long cost = 0;
cost += master->scan_size[next_scan_number-2];
cost += master->scan_size[next_scan_number-1];

if (cost < master->best_freq_split_cost) {
master->best_freq_split_cost = cost;
if (cost < master->best_cost) {
master->best_cost = cost;
master->best_freq_split_idx_luma = idx;
}

Expand All @@ -652,34 +652,35 @@ select_scans (j_compress_ptr cinfo, int next_scan_number)

master->interleave_chroma_dc = master->scan_size[base_scan_idx] <= master->scan_size[base_scan_idx+1] + master->scan_size[base_scan_idx+2];

} else if (next_scan_number == chroma_freq_split_scan_start) {
int Al;
int i;
} else if (next_scan_number > cinfo->num_scans_luma+cinfo->num_scans_chroma_dc && next_scan_number <= chroma_freq_split_scan_start) {
base_scan_idx = cinfo->num_scans_luma + cinfo->num_scans_chroma_dc;
master->best_Al_chroma = 0;

for (Al = 0; Al <= cinfo->Al_max_chroma; Al++) {
size[Al] = master->scan_size[base_scan_idx + 0 + 4 * Al];
size[Al] += master->scan_size[base_scan_idx + 1 + 4 * Al];
size[Al] += master->scan_size[base_scan_idx + 2 + 4 * Al];
size[Al] += master->scan_size[base_scan_idx + 3 + 4 * Al];

if ((next_scan_number - base_scan_idx) % 6 == 4) {
int Al = (next_scan_number - base_scan_idx) / 6;
int i;
unsigned long cost = 0;
cost += master->scan_size[next_scan_number-4];
cost += master->scan_size[next_scan_number-3];
cost += master->scan_size[next_scan_number-2];
cost += master->scan_size[next_scan_number-1];
for (i = 0; i < Al; i++) {
size[Al] += master->scan_size[base_scan_idx + 4 + 4*cinfo->Al_max_chroma + 2*i];
size[Al] += master->scan_size[base_scan_idx + 5 + 4*cinfo->Al_max_chroma + 2*i];
cost += master->scan_size[base_scan_idx + 4 + 6*i];
cost += master->scan_size[base_scan_idx + 5 + 6*i];
}

if (Al == 0 || size[Al] < size[master->best_Al_chroma])
if (Al == 0 || cost < master->best_cost) {
master->best_cost = cost;
master->best_Al_chroma = Al;
else
break;
} else {
master->scan_number = chroma_freq_split_scan_start - 1;
master->pass_number = 2 * master->scan_number + 1;
}
}

} else if (next_scan_number > chroma_freq_split_scan_start && next_scan_number <= cinfo->num_scans) {
if (next_scan_number == chroma_freq_split_scan_start + 2) {
master->best_freq_split_idx_chroma = 0;
master->best_freq_split_cost = master->scan_size[next_scan_number-2];
master->best_freq_split_cost += master->scan_size[next_scan_number-1];
master->best_cost = master->scan_size[next_scan_number-2];
master->best_cost += master->scan_size[next_scan_number-1];

} else if ((next_scan_number - chroma_freq_split_scan_start) % 4 == 2) {
int idx = (next_scan_number - chroma_freq_split_scan_start) >> 2;
Expand All @@ -689,8 +690,8 @@ select_scans (j_compress_ptr cinfo, int next_scan_number)
cost += master->scan_size[next_scan_number-2];
cost += master->scan_size[next_scan_number-1];

if (cost < master->best_freq_split_cost) {
master->best_freq_split_cost = cost;
if (cost < master->best_cost) {
master->best_cost = cost;
master->best_freq_split_idx_chroma = idx;
}

Expand Down Expand Up @@ -732,7 +733,7 @@ select_scans (j_compress_ptr cinfo, int next_scan_number)

/* copy the LSB refinements as well */
for (Al = master->best_Al_luma-1; Al >= min_Al; Al--)
copy_buffer(cinfo, 2*cinfo->Al_max_luma + 3 + Al);
copy_buffer(cinfo, 3 + 3*Al);

if (cinfo->num_scans > cinfo->num_scans_luma) {
if (master->best_freq_split_idx_chroma == 0) {
Expand All @@ -749,17 +750,17 @@ select_scans (j_compress_ptr cinfo, int next_scan_number)
base_scan_idx = cinfo->num_scans_luma + cinfo->num_scans_chroma_dc;

for (Al = master->best_Al_chroma-1; Al >= min_Al; Al--) {
copy_buffer(cinfo, base_scan_idx + 4*(cinfo->Al_max_chroma+1) + 2*Al + 0);
copy_buffer(cinfo, base_scan_idx + 4*(cinfo->Al_max_chroma+1) + 2*Al + 1);
copy_buffer(cinfo, base_scan_idx + 6*Al + 4);
copy_buffer(cinfo, base_scan_idx + 6*Al + 5);
}
}

for (Al = min_Al-1; Al >= 0; Al--) {
copy_buffer(cinfo, 2*cinfo->Al_max_luma + 3 + Al);
copy_buffer(cinfo, 3 + 3*Al);

if (cinfo->num_scans > cinfo->num_scans_luma) {
copy_buffer(cinfo, base_scan_idx + 4*(cinfo->Al_max_chroma+1) + 2*Al + 0);
copy_buffer(cinfo, base_scan_idx + 4*(cinfo->Al_max_chroma+1) + 2*Al + 1);
copy_buffer(cinfo, base_scan_idx + 6*Al + 4);
copy_buffer(cinfo, base_scan_idx + 6*Al + 5);
}
}

Expand Down
25 changes: 14 additions & 11 deletions jcparam.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -670,13 +670,14 @@ jpeg_search_progression (j_compress_ptr cinfo)
/* luma DC by itself */
scanptr = fill_dc_scans(scanptr, 1, 0, 0);

for (Al = 0; Al <= cinfo->Al_max_luma; Al++) {
scanptr = fill_a_scan(scanptr, 0, 1, 8, 0, Al);
scanptr = fill_a_scan(scanptr, 0, 9, 63, 0, Al);
}
scanptr = fill_a_scan(scanptr, 0, 1, 8, 0, 0);
scanptr = fill_a_scan(scanptr, 0, 9, 63, 0, 0);

for (Al = 0; Al < cinfo->Al_max_luma; Al++)
for (Al = 0; Al < cinfo->Al_max_luma; Al++) {
scanptr = fill_a_scan(scanptr, 0, 1, 63, Al+1, Al);
scanptr = fill_a_scan(scanptr, 0, 1, 8, 0, Al+1);
scanptr = fill_a_scan(scanptr, 0, 9, 63, 0, Al+1);
}

scanptr = fill_a_scan(scanptr, 0, 1, 63, 0, 0);

Expand All @@ -699,16 +700,18 @@ jpeg_search_progression (j_compress_ptr cinfo)
scanptr = fill_a_scan(scanptr, 1, 0, 0, 0, 0);
scanptr = fill_a_scan(scanptr, 2, 0, 0, 0, 0);

for (Al = 0; Al <= cinfo->Al_max_chroma; Al++) {
scanptr = fill_a_scan(scanptr, 1, 1, 8, 0, Al);
scanptr = fill_a_scan(scanptr, 1, 9, 63, 0, Al);
scanptr = fill_a_scan(scanptr, 2, 1, 8, 0, Al);
scanptr = fill_a_scan(scanptr, 2, 9, 63, 0, Al);
}
scanptr = fill_a_scan(scanptr, 1, 1, 8, 0, 0);
scanptr = fill_a_scan(scanptr, 1, 9, 63, 0, 0);
scanptr = fill_a_scan(scanptr, 2, 1, 8, 0, 0);
scanptr = fill_a_scan(scanptr, 2, 9, 63, 0, 0);

for (Al = 0; Al < cinfo->Al_max_chroma; Al++) {
scanptr = fill_a_scan(scanptr, 1, 1, 63, Al+1, Al);
scanptr = fill_a_scan(scanptr, 2, 1, 63, Al+1, Al);
scanptr = fill_a_scan(scanptr, 1, 1, 8, 0, Al+1);
scanptr = fill_a_scan(scanptr, 1, 9, 63, 0, Al+1);
scanptr = fill_a_scan(scanptr, 2, 1, 8, 0, Al+1);
scanptr = fill_a_scan(scanptr, 2, 9, 63, 0, Al+1);
}

scanptr = fill_a_scan(scanptr, 1, 1, 63, 0, 0);
Expand Down

0 comments on commit c92da45

Please sign in to comment.