/*
* Read an EBML header.
*/
char *ebml_read_header(stream_t *s, int *version)
{
uint64_t length, l, num;
uint32_t id;
char *str = NULL;
if (ebml_read_master(s, &length) != EBML_ID_HEADER)
return 0;
if (version)
*version = 1;
while (length > 0) {
id = ebml_read_id(s, NULL);
if (id == EBML_ID_INVALID)
return NULL;
length -= 2;
switch (id) {
/* is our read version uptodate? */
case EBML_ID_EBMLREADVERSION:
num = ebml_read_uint(s, &l);
if (num != EBML_VERSION)
return NULL;
break;
/* we only handle 8 byte lengths at max */
case EBML_ID_EBMLMAXSIZELENGTH:
num = ebml_read_uint(s, &l);
if (num != sizeof(uint64_t))
return NULL;
break;
/* we handle 4 byte IDs at max */
case EBML_ID_EBMLMAXIDLENGTH:
num = ebml_read_uint(s, &l);
if (num != sizeof(uint32_t))
return NULL;
break;
case EBML_ID_DOCTYPE:
str = ebml_read_ascii(s, &l);
if (str == NULL)
return NULL;
break;
case EBML_ID_DOCTYPEREADVERSION:
num = ebml_read_uint(s, &l);
if (num == EBML_UINT_INVALID)
return NULL;
if (version)
*version = num;
break;
/* we ignore these two, they don't tell us anything we care about */
case EBML_ID_VOID:
case EBML_ID_EBMLVERSION:
case EBML_ID_DOCTYPEVERSION:
default:
if (ebml_read_skip(s, &l))
return NULL;
break;
}
length -= l;
}
return str;
}
int ebml_check_header(ebml_parser_t *ebml) {
uint32_t next_level;
ebml_elem_t master;
if (!ebml_read_elem_head(ebml, &master)) {
xprintf(ebml->xine, XINE_VERBOSITY_LOG,
"ebml: invalid master element\n");
return 0;
}
if (master.id != EBML_ID_EBML) {
xprintf(ebml->xine, XINE_VERBOSITY_LOG,
"ebml: invalid master element\n");
return 0;
}
if (!ebml_read_master (ebml, &master))
return 0;
next_level = 1;
while (next_level == 1) {
ebml_elem_t elem;
if (!ebml_read_elem_head(ebml, &elem))
return 0;
switch (elem.id) {
case EBML_ID_EBMLVERSION: {
uint64_t num;
if (!ebml_read_uint (ebml, &elem, &num))
return 0;
lprintf("ebml_version: %" PRIu64 "\n", num);
ebml->version = num;
break;
}
case EBML_ID_EBMLREADVERSION: {
uint64_t num;
if (!ebml_read_uint (ebml, &elem, &num))
return 0;
lprintf("ebml_read_version: %" PRIu64 "\n", num);
if (num != EBML_VERSION)
return 0;
ebml->read_version = num;
break;
}
case EBML_ID_EBMLMAXIDLENGTH: {
uint64_t num;
if (!ebml_read_uint (ebml, &elem, &num))
return 0;
lprintf("ebml_max_id_length: %" PRIu64 "\n", num);
ebml->max_id_len = num;
break;
}
case EBML_ID_EBMLMAXSIZELENGTH: {
uint64_t num;
if (!ebml_read_uint (ebml, &elem, &num))
return 0;
lprintf("ebml_max_size_length: %" PRIu64 "\n", num);
ebml->max_size_len = num;
break;
}
case EBML_ID_DOCTYPE: {
char *text = ebml_alloc_read_ascii (ebml, &elem);
if (!text)
return 0;
lprintf("doctype: %s\n", text);
if (ebml->doctype)
free (ebml->doctype);
ebml->doctype = text;
break;
}
case EBML_ID_DOCTYPEVERSION: {
uint64_t num;
if (!ebml_read_uint (ebml, &elem, &num))
return 0;
lprintf("doctype_version: %" PRIu64 "\n", num);
ebml->doctype_version = num;
break;
}
case EBML_ID_DOCTYPEREADVERSION: {
uint64_t num;
if (!ebml_read_uint (ebml, &elem, &num))
return 0;
lprintf("doctype_read_version: %" PRIu64 "\n", num);
ebml->doctype_read_version = num;
break;
}
default:
xprintf(ebml->xine, XINE_VERBOSITY_LOG,
"ebml: Unknown data type 0x%x in EBML header (ignored)\n", elem.id);
ebml_skip(ebml, &elem);
}
next_level = ebml_get_next_level(ebml, &elem);
}
return 1;
}
