/* Create a marker segment of the specified type. */
jpc_ms_t *jpc_ms_create(int type)
{
jpc_ms_t *ms;
jpc_mstabent_t *mstabent;
if (!(ms = jas_malloc(sizeof(jpc_ms_t)))) {
return 0;
}
ms->id = type;
ms->len = 0;
mstabent = jpc_mstab_lookup(ms->id);
ms->ops = &mstabent->ops;
memset(&ms->parms, 0, sizeof(jpc_msparms_t));
return ms;
}
/* Dump a marker segment to a stream for debugging. */
void jpc_ms_dump(jpc_ms_t *ms, FILE *out)
{
jpc_mstabent_t *mstabent;
mstabent = jpc_mstab_lookup(ms->id);
fprintf(out, "type = 0x%04x (%s);", ms->id, mstabent->name);
if (JPC_MS_HASPARMS(ms->id)) {
fprintf(out, " len = %d;", ms->len + 2);
if (ms->ops->dumpparms) {
(*ms->ops->dumpparms)(ms, out);
} else {
fprintf(out, "\n");
}
} else {
fprintf(out, "\n");
}
}
/* Read a marker segment from a stream. */
jpc_ms_t *jpc_getms(jas_stream_t *in, jpc_cstate_t *cstate)
{
long file_offset = jas_stream_tell(in);
long seek_offset = jas_rtc_SkipMarkerSegment(file_offset);
if (seek_offset > 0 && jas_stream_seek(in, seek_offset, SEEK_CUR) < 0)
return NULL;
jpc_ms_t *ms;
jpc_mstabent_t *mstabent;
jas_stream_t *tmpstream;
if (!(ms = jpc_ms_create(0))) {
return 0;
}
/* Get the marker type. */
if (jpc_getuint16(in, &ms->id) || ms->id < JPC_MS_MIN
#ifndef __MINGW32__
|| ms->id > JPC_MS_MAX
#endif
) {
jpc_ms_destroy(ms);
return 0;
}
jas_rtc_MarkerSegment(file_offset, ms->id);
mstabent = jpc_mstab_lookup(ms->id);
ms->ops = &mstabent->ops;
/* Get the marker segment length and parameters if present. */
/* Note: It is tacitly assumed that a marker segment cannot have
parameters unless it has a length field. That is, there cannot
be a parameters field without a length field and vice versa. */
if (JPC_MS_HASPARMS(ms->id)) {
/* Get the length of the marker segment. */
if (jpc_getuint16(in, &ms->len) || ms->len < 3) {
jpc_ms_destroy(ms);
return 0;
}
/* Calculate the length of the marker segment parameters. */
ms->len -= 2;
/* Create and prepare a temporary memory stream from which to
read the marker segment parameters. */
/* Note: This approach provides a simple way of ensuring that
we never read beyond the end of the marker segment (even if
the marker segment length is errantly set too small). */
if (!(tmpstream = jas_stream_memopen(0, 0))) {
jpc_ms_destroy(ms);
return 0;
}
if (jas_stream_copy(tmpstream, in, ms->len) ||
jas_stream_seek(tmpstream, 0, SEEK_SET) < 0) {
jas_stream_close(tmpstream);
jpc_ms_destroy(ms);
return 0;
}
/* Get the marker segment parameters. */
if ((*ms->ops->getparms)(ms, cstate, tmpstream)) {
ms->ops = 0;
jpc_ms_destroy(ms);
jas_stream_close(tmpstream);
return 0;
}
#if 0 // JMW
if (JAS_CAST(ulong, jas_stream_tell(tmpstream)) != ms->len) {
fprintf(stderr,
"warning: trailing garbage in marker segment (%ld bytes)\n",
ms->len - jas_stream_tell(tmpstream));
}
#endif
/* Close the temporary stream. */
jas_stream_close(tmpstream);
} else {
/* There are no marker segment parameters. */
ms->len = 0;
}
/* Update the code stream state information based on the type of
marker segment read. */
/* Note: This is a bit of a hack, but I'm not going to define another
type of virtual function for this one special case. */
if (ms->id == JPC_MS_SIZ) {
cstate->numcomps = ms->parms.siz.numcomps;
}
return ms;
}
/* Read a marker segment from a stream. */
jpc_ms_t *jpc_getms(jas_stream_t *in, jpc_cstate_t *cstate)
{
jpc_ms_t *ms;
jpc_mstabent_t *mstabent;
jas_stream_t *tmpstream;
if (!(ms = jpc_ms_create(0))) {
return 0;
}
/* Get the marker type. */
if (jpc_getuint16(in, &ms->id) || ms->id < JPC_MS_MIN ||
ms->id > JPC_MS_MAX) {
jpc_ms_destroy(ms);
return 0;
}
mstabent = jpc_mstab_lookup(ms->id);
ms->ops = &mstabent->ops;
/* Get the marker segment length and parameters if present. */
/* Note: It is tacitly assumed that a marker segment cannot have
parameters unless it has a length field. That is, there cannot
be a parameters field without a length field and vice versa. */
if (JPC_MS_HASPARMS(ms->id)) {
/* Get the length of the marker segment. */
if (jpc_getuint16(in, &ms->len) || ms->len < 3) {
jpc_ms_destroy(ms);
return 0;
}
/* Calculate the length of the marker segment parameters. */
ms->len -= 2;
/* Create and prepare a temporary memory stream from which to
read the marker segment parameters. */
/* Note: This approach provides a simple way of ensuring that
we never read beyond the end of the marker segment (even if
the marker segment length is errantly set too small). */
if (!(tmpstream = jas_stream_memopen(0, 0))) {
jpc_ms_destroy(ms);
return 0;
}
if (jas_stream_copy(tmpstream, in, ms->len) ||
jas_stream_seek(tmpstream, 0, SEEK_SET) < 0) {
jas_stream_close(tmpstream);
jpc_ms_destroy(ms);
return 0;
}
/* Get the marker segment parameters. */
if ((*ms->ops->getparms)(ms, cstate, tmpstream)) {
ms->ops = 0;
jpc_ms_destroy(ms);
jas_stream_close(tmpstream);
return 0;
}
if (jas_getdbglevel() > 0) {
jpc_ms_dump(ms, stderr);
}
if (JAS_CAST(unsigned long, jas_stream_tell(tmpstream)) != ms->len) {
fprintf(stderr,
"warning: trailing garbage in marker segment (%ld bytes)\n",
ms->len - jas_stream_tell(tmpstream));
}
/* Close the temporary stream. */
jas_stream_close(tmpstream);
} else {
