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 8c461845c8
commit 1ae40e502d
8 changed files with 100 additions and 21 deletions

View File

@@ -29,8 +29,13 @@
#include "asterisk.h"
#include <ctype.h> /* for tolower */
#include "asterisk/module.h"
#include "asterisk/format.h"
#include "asterisk/astobj2.h" /* for ao2_bump */
#include "asterisk/logger.h" /* for ast_log, LOG_WARNING */
#include "asterisk/strings.h" /* for ast_str_append */
/* Destroy is a required callback and must exist */
static void siren7_destroy(struct ast_format *format)
@@ -45,9 +50,15 @@ static int siren7_clone(const struct ast_format *src, struct ast_format *dst)
static struct ast_format *siren7_parse_sdp_fmtp(const struct ast_format *format, const char *attributes)
{
char *attribs = ast_strdupa(attributes), *attrib;
unsigned int val;
if (sscanf(attributes, "bitrate=%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 (sscanf(attribs, "bitrate=%30u", &val) == 1) {
if (val != 32000) {
ast_log(LOG_WARNING, "Got Siren7 offer at %u bps, but only 32000 bps supported; ignoring.\n", val);
return NULL;