gstreamer/subprojects/gst-plugins-good/gst/rtpmanager/gstrtphdrext-mid.c

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/* GStreamer
* Copyright (C) <2021> Matthew Waters <matthew@centricular.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
/**
* SECTION:element-rtphdrextmid
* @title: rtphdrextmid
* @short_description: RTP Bundle Media Identification (MID) RTP Header
* Extension (RFC8843)
* @see_also: #GstRTPHeaderExtension, #GstRTPBasePayload, #GstRTPBaseDepayload, gstrtpbuffer
*
* Since: 1.22
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <gst/rtp/gstrtpbuffer.h>
#include "gstrtphdrext-mid.h"
GST_DEBUG_CATEGORY_STATIC (rtphdrext_mid_debug);
#define GST_CAT_DEFAULT (rtphdrext_mid_debug)
#define MID_EXTMAP_STR GST_RTP_HDREXT_BASE "sdes:mid"
enum
{
PROP_0,
PROP_MID,
};
struct _GstRTPHeaderExtensionMid
{
GstRTPHeaderExtension parent;
char *mid;
};
#define parent_class gst_rtp_header_extension_mid_parent_class
G_DEFINE_TYPE_WITH_CODE (GstRTPHeaderExtensionMid,
gst_rtp_header_extension_mid, GST_TYPE_RTP_HEADER_EXTENSION,
GST_DEBUG_CATEGORY_INIT (GST_CAT_DEFAULT, "rtphdrext-mid", 0,
"RTP BUNDLE MID Header Extensions (RFC8843)")
);
GST_ELEMENT_REGISTER_DEFINE (rtphdrextmid, "rtphdrextmid",
GST_RANK_MARGINAL, GST_TYPE_RTP_HEADER_EXTENSION_MID);
static GstRTPHeaderExtensionFlags
gst_rtp_header_extension_mid_get_supported_flags (GstRTPHeaderExtension * ext)
{
GstRTPHeaderExtensionMid *self = GST_RTP_HEADER_EXTENSION_MID (ext);
GstRTPHeaderExtensionFlags flags =
GST_RTP_HEADER_EXTENSION_ONE_BYTE | GST_RTP_HEADER_EXTENSION_TWO_BYTE;
gssize mid_len = -1;
GST_OBJECT_LOCK (ext);
if (self->mid)
mid_len = strlen (self->mid);
GST_OBJECT_UNLOCK (ext);
if (mid_len > 16)
flags = GST_RTP_HEADER_EXTENSION_TWO_BYTE;
return flags;
}
static gsize
gst_rtp_header_extension_mid_get_max_size (GstRTPHeaderExtension * ext,
const GstBuffer * buffer)
{
if (gst_rtp_header_extension_mid_get_supported_flags (ext) &
GST_RTP_HEADER_EXTENSION_ONE_BYTE)
return 16;
else
return 255;
}
static gssize
gst_rtp_header_extension_mid_write (GstRTPHeaderExtension * ext,
const GstBuffer * input_meta, GstRTPHeaderExtensionFlags write_flags,
GstBuffer * output, guint8 * data, gsize size)
{
GstRTPHeaderExtensionMid *self = GST_RTP_HEADER_EXTENSION_MID (ext);
gsize len = 0;
g_return_val_if_fail (size >=
gst_rtp_header_extension_mid_get_max_size (ext, NULL), -1);
g_return_val_if_fail (write_flags &
gst_rtp_header_extension_mid_get_supported_flags (ext), -1);
GST_OBJECT_LOCK (ext);
if (!self->mid) {
GST_LOG_OBJECT (self, "no mid to write");
goto out;
}
/* TODO: we don't need to always add mid, we can selectively omit it from e.g.
* non-video-keyframes or some percentage of the produced frames, e.g. RFC8843
* mentions possibly using packet-loss as a indication of how often to add mid
* to packets */
len = strlen (self->mid);
if ((write_flags & GST_RTP_HEADER_EXTENSION_TWO_BYTE) == 0 && len > 16) {
GST_DEBUG_OBJECT (self, "cannot write a mid of size %" G_GSIZE_FORMAT
" without using the two byte extension format", len);
len = 0;
goto out;
}
if (len > 0) {
GST_LOG_OBJECT (self, "writing mid \'%s\'", self->mid);
memcpy (data, self->mid, len);
}
out:
GST_OBJECT_UNLOCK (ext);
return len;
}
static gboolean
gst_rtp_header_extension_mid_read (GstRTPHeaderExtension * ext,
GstRTPHeaderExtensionFlags read_flags, const guint8 * data, gsize size,
GstBuffer * buffer)
{
GstRTPHeaderExtensionMid *self = GST_RTP_HEADER_EXTENSION_MID (ext);
gboolean notify = FALSE;
if (!data || size == 0)
return TRUE;
if (read_flags & GST_RTP_HEADER_EXTENSION_ONE_BYTE && (size < 1 || size > 16)) {
GST_ERROR_OBJECT (ext,
"one-byte header extensions must be between 1 and 16 bytes inculusive");
return FALSE;
}
GST_OBJECT_LOCK (self);
if (!self->mid || strncmp ((const char *) data, self->mid, size) != 0) {
g_clear_pointer (&self->mid, g_free);
self->mid = g_strndup ((const char *) data, size);
notify = TRUE;
}
GST_OBJECT_UNLOCK (self);
if (notify)
g_object_notify ((GObject *) self, "mid");
return TRUE;
}
static void
gst_rtp_header_extension_mid_get_property (GObject * object,
guint prop_id, GValue * value, GParamSpec * pspec)
{
GstRTPHeaderExtensionMid *self = GST_RTP_HEADER_EXTENSION_MID (object);
switch (prop_id) {
case PROP_MID:
GST_OBJECT_LOCK (self);
g_value_set_string (value, self->mid);
GST_OBJECT_UNLOCK (self);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static gboolean
validate_mid (const char *rid)
{
const char *iter;
/* For avoidance of doubt, the only allowed byte values for
* these IDs are decimal 48 through 57, 65 through 90, and 97 through
* 122.
*/
for (iter = rid; iter && iter[0]; iter++) {
if (iter[0] < 48)
return FALSE;
if (iter[0] > 122)
return FALSE;
if (iter[0] > 57 && iter[0] < 65)
return FALSE;
if (iter[0] > 90 && iter[0] < 97)
return FALSE;
}
return TRUE;
}
static void
gst_rtp_header_extension_mid_set_property (GObject * object,
guint prop_id, const GValue * value, GParamSpec * pspec)
{
GstRTPHeaderExtensionMid *self = GST_RTP_HEADER_EXTENSION_MID (object);
switch (prop_id) {
case PROP_MID:{
const char *mid;
GST_OBJECT_LOCK (self);
mid = g_value_get_string (value);
if (!validate_mid (mid)) {
GST_WARNING_OBJECT (self, "Could not set mid \'%s\'. Validation failed",
mid);
} else {
g_clear_pointer (&self->mid, g_free);
self->mid = g_strdup (mid);
}
GST_OBJECT_UNLOCK (self);
break;
}
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gst_rtp_header_extension_mid_finalize (GObject * object)
{
GstRTPHeaderExtensionMid *self = GST_RTP_HEADER_EXTENSION_MID (object);
g_clear_pointer (&self->mid, g_free);
G_OBJECT_CLASS (parent_class)->finalize (object);
}
static gboolean
gst_rtp_header_extension_mid_set_caps_from_attributes (GstRTPHeaderExtension
* ext, GstCaps * caps)
{
GstRTPHeaderExtensionMid *self = GST_RTP_HEADER_EXTENSION_MID (ext);
GstStructure *s = gst_caps_get_structure (caps, 0);
if (!GST_RTP_HEADER_EXTENSION_CLASS (parent_class)->set_caps_from_attributes
(ext, caps))
return FALSE;
GST_OBJECT_LOCK (ext);
if (self->mid) {
if (gst_structure_has_field (s, "a-mid")) {
GST_WARNING_OBJECT (ext, "caps already contain the \'a-mid\' field!");
goto error;
}
gst_structure_set (s, "a-mid", G_TYPE_STRING, self->mid, NULL);
GST_DEBUG_OBJECT (ext, "set mid \'%s\' on output caps", self->mid);
}
GST_OBJECT_UNLOCK (ext);
return TRUE;
error:
GST_OBJECT_UNLOCK (ext);
return FALSE;
}
static void
gst_rtp_header_extension_mid_class_init (GstRTPHeaderExtensionMidClass * klass)
{
GstRTPHeaderExtensionClass *rtp_hdr_class;
GstElementClass *gstelement_class;
GObjectClass *gobject_class;
rtp_hdr_class = (GstRTPHeaderExtensionClass *) klass;
gobject_class = (GObjectClass *) klass;
gstelement_class = (GstElementClass *) klass;
gobject_class->set_property = gst_rtp_header_extension_mid_set_property;
gobject_class->get_property = gst_rtp_header_extension_mid_get_property;
gobject_class->finalize = gst_rtp_header_extension_mid_finalize;
/**
* rtphdrextmid:mid:
*
* The Media Identification (MID) value either last retrieved from the RTP
* Header extension, or to set on outgoing RTP packets.
*
* Since: 1.22
*/
g_object_class_install_property (gobject_class, PROP_MID,
g_param_spec_string ("mid", "mid",
"The Media Identification (MID) value last read or to write from/to "
"RTP buffers", NULL, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
rtp_hdr_class->get_supported_flags =
gst_rtp_header_extension_mid_get_supported_flags;
rtp_hdr_class->get_max_size = gst_rtp_header_extension_mid_get_max_size;
rtp_hdr_class->write = gst_rtp_header_extension_mid_write;
rtp_hdr_class->read = gst_rtp_header_extension_mid_read;
rtp_hdr_class->set_caps_from_attributes =
gst_rtp_header_extension_mid_set_caps_from_attributes;
gst_element_class_set_static_metadata (gstelement_class,
"RTP BUNDLE MID Header Extension", GST_RTP_HDREXT_ELEMENT_CLASS,
"Extends RTP packets to add or retrieve a Media Identification (MID) "
"value as specified in RFC8843",
"Matthew Waters <matthew@centricular.com>");
gst_rtp_header_extension_class_set_uri (rtp_hdr_class, MID_EXTMAP_STR);
}
static void
gst_rtp_header_extension_mid_init (GstRTPHeaderExtensionMid * self)
{
}