res_format_attr_*: Parameter Names are Case-Insensitive.

see RFC 4855:
parameter names are case-insensitive both in media type strings and
in the default mapping to the SDP a=fmtp attribute.

This change is required for H.263+ because some implementations are
known to use even mixed-case. This does not fix ASTERISK~29268 because
H.264 was not fixed. This approach here lowers/uppers both parameter
names and parameter values. H.264 needs a different approach because
one of its parameter values is not case-insensitive:
sprop-parameter-sets is Base64.

Change-Id: Idf2a73457be231647aed3c87b1da197afba86892
This commit is contained in:
Alexander Traud
2021-03-05 18:16:56 +01:00
committed by Joshua Colp
parent 4fc0e16838
commit 262473c6d9
8 changed files with 100 additions and 21 deletions

View File

@@ -31,6 +31,8 @@
#include "asterisk.h"
#include <ctype.h> /* for tolower */
#include "asterisk/module.h"
#include "asterisk/format.h"
#include "asterisk/logger.h" /* for ast_log, LOG_WARNING */
@@ -76,6 +78,7 @@ static int vp8_clone(const struct ast_format *src, struct ast_format *dst)
static struct ast_format *vp8_parse_sdp_fmtp(const struct ast_format *format, const char *attributes)
{
char *attribs = ast_strdupa(attributes), *attrib;
struct ast_format *cloned;
struct vp8_attr *attr;
const char *kvp;
@@ -87,13 +90,18 @@ static struct ast_format *vp8_parse_sdp_fmtp(const struct ast_format *format, co
}
attr = ast_format_get_attribute_data(cloned);
if ((kvp = strstr(attributes, "max-fr")) && sscanf(kvp, "max-fr=%30u", &val) == 1) {
/* lower-case everything, so we are case-insensitive */
for (attrib = attribs; *attrib; ++attrib) {
*attrib = tolower(*attrib);
} /* based on channels/chan_sip.c:process_a_sdp_image() */
if ((kvp = strstr(attribs, "max-fr")) && sscanf(kvp, "max-fr=%30u", &val) == 1) {
attr->maximum_frame_rate = val;
} else {
attr->maximum_frame_rate = UINT_MAX;
}
if ((kvp = strstr(attributes, "max-fs")) && sscanf(kvp, "max-fs=%30u", &val) == 1) {
if ((kvp = strstr(attribs, "max-fs")) && sscanf(kvp, "max-fs=%30u", &val) == 1) {
attr->maximum_frame_size = val;
} else {
attr->maximum_frame_size = UINT_MAX;