/**
* gst_sdp_media_get_caps_from_media:
* @media: a #GstSDPMedia
* @pt: a payload type
*
* Mapping of caps from SDP fields:
*
* a=rtpmap:(payload) (encoding_name)/(clock_rate)[/(encoding_params)]
*
* a=framesize:(payload) (width)-(height)
*
* a=fmtp:(payload) (param)[=(value)];...
*
* Returns: a #GstCaps, or %NULL if an error happened
*
* I got it from Gstreamer source cod, release 1.8
*/
GstCaps *
gst_sdp_media_get_caps_from_media (const GstSDPMedia * media, gint pt)
{
GstCaps *caps;
const gchar *rtpmap;
const gchar *fmtp;
const gchar *framesize;
gchar *name = NULL;
gint rate = -1;
gchar *params = NULL;
gchar *tmp;
GstStructure *s;
gint payload = 0;
gboolean ret;
/* get and parse rtpmap */
rtpmap = gst_sdp_get_attribute_for_pt (media, "rtpmap", pt);
if (rtpmap) {
ret = gst_sdp_parse_rtpmap (rtpmap, &payload, &name, &rate, ¶ms);
if (!ret) {
GST_ERROR ("error parsing rtpmap, ignoring");
rtpmap = NULL;
}
}
/* dynamic payloads need rtpmap or we fail */
if (rtpmap == NULL && pt >= 96)
goto no_rtpmap;
/* check if we have a rate, if not, we need to look up the rate from the
* default rates based on the payload types. */
if (rate == -1) {
const GstRTPPayloadInfo *info;
if (GST_RTP_PAYLOAD_IS_DYNAMIC (pt)) {
/* dynamic types, use media and encoding_name */
tmp = g_ascii_strdown (media->media, -1);
info = gst_rtp_payload_info_for_name (tmp, name);
g_free (tmp);
} else {
/* static types, use payload type */
info = gst_rtp_payload_info_for_pt (pt);
}
if (info) {
if ((rate = info->clock_rate) == 0)
rate = -1;
}
/* we fail if we cannot find one */
if (rate == -1)
goto no_rate;
}
tmp = g_ascii_strdown (media->media, -1);
caps = gst_caps_new_simple ("application/x-rtp",
"media", G_TYPE_STRING, tmp, "payload", G_TYPE_INT, pt, NULL);
g_free (tmp);
s = gst_caps_get_structure (caps, 0);
gst_structure_set (s, "clock-rate", G_TYPE_INT, rate, NULL);
/* encoding name must be upper case */
if (name != NULL) {
tmp = g_ascii_strup (name, -1);
gst_structure_set (s, "encoding-name", G_TYPE_STRING, tmp, NULL);
g_free (tmp);
}
/* params must be lower case */
if (params != NULL) {
tmp = g_ascii_strdown (params, -1);
gst_structure_set (s, "encoding-params", G_TYPE_STRING, tmp, NULL);
g_free (tmp);
}
/* parse optional fmtp: field */
if ((fmtp = gst_sdp_get_attribute_for_pt (media, "fmtp", pt))) {
gchar *p;
gint payload = 0;
p = (gchar *) fmtp;
/* p is now of the format <payload> <param>[=<value>];... */
PARSE_INT (p, " ", payload);
if (payload != -1 && payload == pt) {
gchar **pairs;
gint i;
/* <param>[=<value>] are separated with ';' */
pairs = g_strsplit (p, ";", 0);
for (i = 0; pairs[i]; i++) {
gchar *valpos;
const gchar *val, *key;
gint j;
const gchar *reserved_keys[] =
{ "media", "payload", "clock-rate", "encoding-name",
"encoding-params"
};
/* the key may not have a '=', the value can have other '='s */
valpos = strstr (pairs[i], "=");
if (valpos) {
/* we have a '=' and thus a value, remove the '=' with \0 */
*valpos = '\0';
/* value is everything between '=' and ';'. We split the pairs at ;
* boundaries so we can take the remainder of the value. Some servers
* put spaces around the value which we strip off here. Alternatively
* we could strip those spaces in the depayloaders should these spaces
* actually carry any meaning in the future. */
val = g_strstrip (valpos + 1);
} else {
/* simple <param>;.. is translated into <param>=1;... */
val = "1";
}
/* strip the key of spaces, convert key to lowercase but not the value. */
key = g_strstrip (pairs[i]);
/* skip keys from the fmtp, which we already use ourselves for the
* caps. Some software is adding random things like clock-rate into
* the fmtp, and we would otherwise here set a string-typed clock-rate
* in the caps... and thus fail to create valid RTP caps
*/
for (j = 0; j < G_N_ELEMENTS (reserved_keys); j++) {
if (g_ascii_strcasecmp (reserved_keys[j], key) == 0) {
key = "";
break;
}
}
if (strlen (key) > 1) {
tmp = g_ascii_strdown (key, -1);
gst_structure_set (s, tmp, G_TYPE_STRING, val, NULL);
g_free (tmp);
}
}
g_strfreev (pairs);
}
}
/* parse framesize: field */
if ((framesize = gst_sdp_media_get_attribute_val (media, "framesize"))) {
gchar *p;
/* p is now of the format <payload> <width>-<height> */
p = (gchar *) framesize;
PARSE_INT (p, " ", payload);
if (payload != -1 && payload == pt) {
gst_structure_set (s, "a-framesize", G_TYPE_STRING, p, NULL);
}
}
return caps;
/* ERRORS */
no_rtpmap:
{
GST_ERROR ("rtpmap type not given for dynamic payload %d", pt);
return NULL;
}
no_rate:
{
GST_ERROR ("rate unknown for payload type %d", pt);
return NULL;
}
}
/*
* Mapping of caps to and from SDP fields:
*
* m=<media> <UDP port> RTP/AVP <payload>
* a=rtpmap:<payload> <encoding_name>/<clock_rate>[/<encoding_params>]
* a=fmtp:<payload> <param>[=<value>];...
*/
static GstCaps *
gst_sdp_demux_media_to_caps (gint pt, const GstSDPMedia * media)
{
GstCaps *caps;
const gchar *rtpmap;
const gchar *fmtp;
gchar *name = NULL;
gint rate = -1;
gchar *params = NULL;
gchar *tmp;
GstStructure *s;
gint payload = 0;
gboolean ret;
/* get and parse rtpmap */
if ((rtpmap = gst_sdp_media_get_attribute_val (media, "rtpmap"))) {
ret = gst_sdp_demux_parse_rtpmap (rtpmap, &payload, &name, &rate, ¶ms);
if (ret) {
if (payload != pt) {
/* we ignore the rtpmap if the payload type is different. */
g_warning ("rtpmap of wrong payload type, ignoring");
name = NULL;
rate = -1;
params = NULL;
}
} else {
/* if we failed to parse the rtpmap for a dynamic payload type, we have an
* error */
if (pt >= 96)
goto no_rtpmap;
/* else we can ignore */
g_warning ("error parsing rtpmap, ignoring");
}
} else {
/* dynamic payloads need rtpmap or we fail */
if (pt >= 96)
goto no_rtpmap;
}
/* check if we have a rate, if not, we need to look up the rate from the
* default rates based on the payload types. */
if (rate == -1) {
const GstRTPPayloadInfo *info;
if (GST_RTP_PAYLOAD_IS_DYNAMIC (pt)) {
/* dynamic types, use media and encoding_name */
tmp = g_ascii_strdown (media->media, -1);
info = gst_rtp_payload_info_for_name (tmp, name);
g_free (tmp);
} else {
/* static types, use payload type */
info = gst_rtp_payload_info_for_pt (pt);
}
if (info) {
if ((rate = info->clock_rate) == 0)
rate = -1;
}
/* we fail if we cannot find one */
if (rate == -1)
goto no_rate;
}
tmp = g_ascii_strdown (media->media, -1);
caps = gst_caps_new_simple ("application/x-rtp",
"media", G_TYPE_STRING, tmp, "payload", G_TYPE_INT, pt, NULL);
g_free (tmp);
s = gst_caps_get_structure (caps, 0);
gst_structure_set (s, "clock-rate", G_TYPE_INT, rate, NULL);
/* encoding name must be upper case */
if (name != NULL) {
tmp = g_ascii_strup (name, -1);
gst_structure_set (s, "encoding-name", G_TYPE_STRING, tmp, NULL);
g_free (tmp);
}
/* params must be lower case */
if (params != NULL) {
tmp = g_ascii_strdown (params, -1);
gst_structure_set (s, "encoding-params", G_TYPE_STRING, tmp, NULL);
g_free (tmp);
}
/* parse optional fmtp: field */
if ((fmtp = gst_sdp_media_get_attribute_val (media, "fmtp"))) {
gchar *p;
gint payload = 0;
p = (gchar *) fmtp;
/* p is now of the format <payload> <param>[=<value>];... */
PARSE_INT (p, " ", payload);
if (payload != -1 && payload == pt) {
gchar **pairs;
gint i;
/* <param>[=<value>] are separated with ';' */
pairs = g_strsplit (p, ";", 0);
for (i = 0; pairs[i]; i++) {
gchar *valpos, *key;
const gchar *val;
/* the key may not have a '=', the value can have other '='s */
valpos = strstr (pairs[i], "=");
if (valpos) {
/* we have a '=' and thus a value, remove the '=' with \0 */
*valpos = '\0';
/* value is everything between '=' and ';'. FIXME, strip? */
val = g_strstrip (valpos + 1);
} else {
/* simple <param>;.. is translated into <param>=1;... */
val = "1";
}
/* strip the key of spaces, convert key to lowercase but not the value. */
key = g_strstrip (pairs[i]);
if (strlen (key) > 1) {
tmp = g_ascii_strdown (key, -1);
gst_structure_set (s, tmp, G_TYPE_STRING, val, NULL);
g_free (tmp);
}
}
g_strfreev (pairs);
}
}
return caps;
/* ERRORS */
no_rtpmap:
{
g_warning ("rtpmap type not given for dynamic payload %d", pt);
return NULL;
}
no_rate:
{
g_warning ("rate unknown for payload type %d", pt);
return NULL;
}
}
