/* Write a marker segment to a stream. */
int jpc_putms(jas_stream_t *out, jpc_cstate_t *cstate, jpc_ms_t *ms)
{
jas_stream_t *tmpstream;
int len;
/* Output the marker segment type. */
if (jpc_putuint16(out, ms->id)) {
return -1;
}
/* Output the marker segment length and parameters if necessary. */
if (ms->ops->putparms) {
/* Create a temporary stream in which to buffer the
parameter data. */
if (!(tmpstream = jas_stream_memopen(0, 0))) {
return -1;
}
if ((*ms->ops->putparms)(ms, cstate, tmpstream)) {
jas_stream_close(tmpstream);
return -1;
}
/* Get the number of bytes of parameter data written. */
if ((len = jas_stream_tell(tmpstream)) < 0) {
jas_stream_close(tmpstream);
return -1;
}
ms->len = len;
/* Write the marker segment length and parameter data to
the output stream. */
if (jas_stream_seek(tmpstream, 0, SEEK_SET) < 0 ||
jpc_putuint16(out, ms->len + 2) ||
jas_stream_copy(out, tmpstream, ms->len) < 0) {
jas_stream_close(tmpstream);
return -1;
}
/* Close the temporary stream. */
jas_stream_close(tmpstream);
}
/* 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;
}
if (jas_getdbglevel() > 0) {
jpc_ms_dump(ms, stderr);
}
return 0;
}
/* 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 {
/* 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
#ifndef __MINGW32__
|| ms->id > JPC_MS_MAX
#endif
) {
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 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;
if (jas_getdbglevel() > 0) {
jpc_ms_dump(ms, stderr);
}
}
/* 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;
}
