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Fixed a bug in JPWL module, which prevented to exploit the full error correction capability of RS codes (e.g. it gave up at 5 errors, even if 6 were correctable); defined a JPWL_MAXIMUM_EPB_ROOM for better customization of the maximum dimension of EPBs (the dimension is pre-calculated on an hypothesis, if it goes beyond 65535 there will be problems, thus we give a little less than the max, let's say 65450)

This commit is contained in:
Giuseppe Baruffa 2007-07-12 08:31:01 +00:00
parent bdb18ab19c
commit 4a50efe542
3 changed files with 21 additions and 16 deletions
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3
ChangeLog
View File

@ -5,6 +5,9 @@ What's New for OpenJPEG
! : changed ! : changed
+ : added + : added
July 12, 2007
* [GB] fixed a bug in JPWL module, which prevented to exploit the full error correction capability of RS codes (e.g. it gave up at 5 errors, even if 6 were correctable); defined a JPWL_MAXIMUM_EPB_ROOM for better customization of the maximum dimension of EPBs (the dimension is pre-calculated on an hypothesis, if it goes beyond 65535 there will be problems, thus we give a little less than the max, let's say 65450)
July 8, 2007 July 8, 2007
* [ANTONIN] fixed the size of the memory allocation in cio.c (confusion between bits and bytes) * [ANTONIN] fixed the size of the memory allocation in cio.c (confusion between bits and bytes)

33
jpwl/jpwl_lib.c
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@ -128,20 +128,20 @@ int jpwl_epbs_add(opj_j2k_t *j2k, jpwl_marker_t *jwmarker, int *jwmarker_num,
while (post_len > 0) { while (post_len > 0) {
/* maximum postlen in order to respect EPB size /* maximum postlen in order to respect EPB size
(we use 65450 instead of 65535 for keeping room for EPB parms)*/ (we use JPWL_MAXIMUM_EPB_ROOM instead of 65535 for keeping room for EPB parms)*/
/* (message word size) * (number of containable parity words) */ /* (message word size) * (number of containable parity words) */
max_postlen = k_post * (unsigned long int) floor(65450.0 / (double) (n_post - k_post)); max_postlen = k_post * (unsigned long int) floor((double) JPWL_MAXIMUM_EPB_ROOM / (double) (n_post - k_post));
/* maximum postlen in order to respect EPB size */ /* maximum postlen in order to respect EPB size */
if (*idx == 0) if (*idx == 0)
/* (we use (65500 - L2) instead of 65535 for keeping room for EPB parms + pre-data) */ /* (we use (JPWL_MAXIMUM_EPB_ROOM - L2) instead of 65535 for keeping room for EPB parms + pre-data) */
/* (message word size) * (number of containable parity words) */ /* (message word size) * (number of containable parity words) */
max_postlen = k_post * (unsigned long int) floor((double) (65500 - L2) / (double) (n_post - k_post)); max_postlen = k_post * (unsigned long int) floor((double) (JPWL_MAXIMUM_EPB_ROOM - L2) / (double) (n_post - k_post));
else else
/* (we use 65500 instead of 65535 for keeping room for EPB parms) */ /* (we use JPWL_MAXIMUM_EPB_ROOM instead of 65535 for keeping room for EPB parms) */
/* (message word size) * (number of containable parity words) */ /* (message word size) * (number of containable parity words) */
max_postlen = k_post * (unsigned long int) floor(65500.0 / (double) (n_post - k_post)); max_postlen = k_post * (unsigned long int) floor((double) JPWL_MAXIMUM_EPB_ROOM / (double) (n_post - k_post));
/* length to use */ /* length to use */
dL4 = min(max_postlen, post_len); dL4 = min(max_postlen, post_len);
@ -793,7 +793,7 @@ bool jpwl_epb_correct(opj_j2k_t *j2k, unsigned char *buffer, int type, int pre_l
/* Initialize RS structures */ /* Initialize RS structures */
P = n_pre - k_pre; P = n_pre - k_pre;
NN_P = NN - P; NN_P = NN - P;
tt = (int) floor((float) P / 2.0F); tt = (int) floor((float) P / 2.0F); /* correction capability of the code */
memset(codeword, 0, NN); memset(codeword, 0, NN);
parityword = codeword + NN_P; parityword = codeword + NN_P;
init_rs(NN_P); init_rs(NN_P);
@ -834,7 +834,8 @@ bool jpwl_epb_correct(opj_j2k_t *j2k, unsigned char *buffer, int type, int pre_l
/*if (conn == NULL) /*if (conn == NULL)
opj_event_msg(j2k->cinfo, EVT_INFO, "codeword is correctly decoded\n");*/ opj_event_msg(j2k->cinfo, EVT_INFO, "codeword is correctly decoded\n");*/
} else if (status < tt) { } else if (status <= tt) {
/* it has corrected 0 <= errs <= tt */
/*if (conn == NULL) /*if (conn == NULL)
opj_event_msg(j2k->cinfo, EVT_WARNING, "%d errors corrected in codeword\n", status);*/ opj_event_msg(j2k->cinfo, EVT_WARNING, "%d errors corrected in codeword\n", status);*/
errnum += status; errnum += status;
@ -848,21 +849,21 @@ bool jpwl_epb_correct(opj_j2k_t *j2k, unsigned char *buffer, int type, int pre_l
/* advance parity buffer */ /* advance parity buffer */
if ((status >= 0) && (status < tt)) if ((status >= 0) && (status <= tt))
/* copy back corrected parity only if all is OK */ /* copy back corrected parity only if all is OK */
memcpy(L2_buf, parityword, P); memcpy(L2_buf, parityword, P);
L2_buf += P; L2_buf += P;
/* advance message buffer */ /* advance message buffer */
if (remaining < k_pre) { if (remaining < k_pre) {
if ((status >= 0) && (status < tt)) if ((status >= 0) && (status <= tt))
/* copy back corrected data only if all is OK */ /* copy back corrected data only if all is OK */
memcpy(L1_buf, codeword, remaining); memcpy(L1_buf, codeword, remaining);
L1_buf += remaining; L1_buf += remaining;
remaining = 0; remaining = 0;
} else { } else {
if ((status >= 0) && (status < tt)) if ((status >= 0) && (status <= tt))
/* copy back corrected data only if all is OK */ /* copy back corrected data only if all is OK */
memcpy(L1_buf, codeword, k_pre); memcpy(L1_buf, codeword, k_pre);
L1_buf += k_pre; L1_buf += k_pre;
@ -1043,7 +1044,7 @@ bool jpwl_epb_correct(opj_j2k_t *j2k, unsigned char *buffer, int type, int pre_l
/* Initialize RS structures */ /* Initialize RS structures */
P = n_post - k_post; P = n_post - k_post;
NN_P = NN - P; NN_P = NN - P;
tt = (int) floor((float) P / 2.0F); tt = (int) floor((float) P / 2.0F); /* again, correction capability */
memset(codeword, 0, NN); memset(codeword, 0, NN);
parityword = codeword + NN_P; parityword = codeword + NN_P;
init_rs(NN_P); init_rs(NN_P);
@ -1080,7 +1081,7 @@ bool jpwl_epb_correct(opj_j2k_t *j2k, unsigned char *buffer, int type, int pre_l
/*if (conn == NULL) /*if (conn == NULL)
opj_event_msg(j2k->cinfo, EVT_INFO, "codeword is correctly decoded\n");*/ opj_event_msg(j2k->cinfo, EVT_INFO, "codeword is correctly decoded\n");*/
} else if (status < tt) { } else if (status <= tt) {
/*if (conn == NULL) /*if (conn == NULL)
opj_event_msg(j2k->cinfo, EVT_WARNING, "%d errors corrected in codeword\n", status);*/ opj_event_msg(j2k->cinfo, EVT_WARNING, "%d errors corrected in codeword\n", status);*/
errnum += status; errnum += status;
@ -1094,21 +1095,21 @@ bool jpwl_epb_correct(opj_j2k_t *j2k, unsigned char *buffer, int type, int pre_l
/* advance parity buffer */ /* advance parity buffer */
if ((status >= 0) && (status < tt)) if ((status >= 0) && (status <= tt))
/* copy back corrected data only if all is OK */ /* copy back corrected data only if all is OK */
memcpy(L3_buf, parityword, P); memcpy(L3_buf, parityword, P);
L3_buf += P; L3_buf += P;
/* advance message buffer */ /* advance message buffer */
if (remaining < k_post) { if (remaining < k_post) {
if ((status >= 0) && (status < tt)) if ((status >= 0) && (status <= tt))
/* copy back corrected data only if all is OK */ /* copy back corrected data only if all is OK */
memcpy(L4_buf, codeword, remaining); memcpy(L4_buf, codeword, remaining);
L4_buf += remaining; L4_buf += remaining;
remaining = 0; remaining = 0;
} else { } else {
if ((status >= 0) && (status < tt)) if ((status >= 0) && (status <= tt))
/* copy back corrected data only if all is OK */ /* copy back corrected data only if all is OK */
memcpy(L4_buf, codeword, k_post); memcpy(L4_buf, codeword, k_post);
L4_buf += k_post; L4_buf += k_post;

1
libopenjpeg/openjpeg.h
View File

@ -104,6 +104,7 @@ braindamage below.
#define JPWL_EXPECTED_COMPONENTS 3 /**< Expect this number of components, so you'll find better the first EPB */ #define JPWL_EXPECTED_COMPONENTS 3 /**< Expect this number of components, so you'll find better the first EPB */
#define JPWL_MAXIMUM_TILES 8192 /**< Expect this maximum number of tiles, to avoid some crashes */ #define JPWL_MAXIMUM_TILES 8192 /**< Expect this maximum number of tiles, to avoid some crashes */
#define JPWL_MAXIMUM_HAMMING 2 /**< Expect this maximum number of bit errors in marker id's */ #define JPWL_MAXIMUM_HAMMING 2 /**< Expect this maximum number of bit errors in marker id's */
#define JPWL_MAXIMUM_EPB_ROOM 65450 /**< Expect this maximum number of bytes for composition of EPBs */
/* <<UniPG */ /* <<UniPG */
/* /*