gstreamer/subprojects/gst-plugins-good/gst/rtp/gstrtppassthroughpay.c
Matthew Waters c3cc8205b2 rtppassthroughpay: ensure buffer is writable before mapping writable
It is entirely possible that the incoming buffer into _chain() is not writable
and will result in a critical when trying to map().

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/8131>
2024-12-12 12:06:13 +11:00

568 lines
18 KiB
C

/*
* GStreamer
*
* Copyright (C) 2023 Sebastian Dröge <sebastian@centricular.com>
* Copyright (C) 2023 Jonas Danielsson <jonas.danielsson@spiideo.com>
*
* gstrtppassthroughpay.c:
*
* 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.
*/
/**
* SECTION:element-rtppassthroughpay
* @title: rtppassthroughpay
*
* This elements pass RTP packets along unchanged and appear as a RTP
* payloader element to the outside world.
*
* This is useful, for example, in the case where you are receiving RTP
* packets from a different source and want to serve them over RTSP. Since the
* gst-rtsp-server library expect the element marked as `payX` to be a RTP
* payloader element and assumes certain properties are available.
*
* ## Example pipelines
*
* |[
* gst-launch-1.0 rtpbin name=rtpbin \
* videotestsrc ! videoconvert ! x264enc ! rtph264pay ! rtpbin.send_rtp_sink_0 \
* rtpbin.send_rtp_src_0 ! udpsink port=5000
* ]| Encode and payload H264 video from videotestsrc. The H264 RTP packets are
* sent on UDP port 5000.
* |[
* test-launch "( udpsrc port=5000 caps=application/x-rtp, ..." ! .recv_rtp_sink_0 \
* rtpbin ! rtppassthroughpay name=pay0 )"
* ]| Setup a gstreamer-rtsp-server using the example tool, it will listen for
* H264 RTP packets on port 5000 and present them using the rtppassthroughpay
* element as the well-known payloader pay0.
*
* Since: 1.24
*/
#include <gst/rtp/rtp.h>
#include "gstrtpelements.h"
#include "gstrtppassthroughpay.h"
GST_DEBUG_CATEGORY_STATIC (gst_rtp_passthrough_pay_debug);
#define GST_CAT_DEFAULT gst_rtp_passthrough_pay_debug
#define PAYLOAD_TYPE_INVALID 128 /* valid range is 0 - 127 (seven bits) */
G_DEFINE_TYPE (GstRtpPassthroughPay, gst_rtp_passthrough_pay, GST_TYPE_ELEMENT);
GST_ELEMENT_REGISTER_DEFINE_WITH_CODE (rtppassthroughpay,
"rtppassthroughpay", GST_RANK_NONE, GST_TYPE_RTP_PASSTHROUGH_PAY,
rtp_element_init (plugin));
static GstStaticPadTemplate src_template =
GST_STATIC_PAD_TEMPLATE ("src", GST_PAD_SRC, GST_PAD_ALWAYS,
GST_STATIC_CAPS ("application/x-rtp, " "payload = (int) [ 0, 127 ],"
"clock-rate = (int) [ 1, 2147483647 ]"));
static GstStaticPadTemplate sink_template =
GST_STATIC_PAD_TEMPLATE ("sink", GST_PAD_SINK, GST_PAD_ALWAYS,
GST_STATIC_CAPS ("application/x-rtp, " "payload = (int) [ 0, 127 ],"
"clock-rate = (int) [ 1, 2147483647 ]"));
#define GST_RTPPASSTHROUGHPAY_RETIMESTAMP_MODE_TYPE (gst_rtp_passthrough_pay_retimestamp_mode_get_type())
static GType
gst_rtp_passthrough_pay_retimestamp_mode_get_type (void)
{
static GType mode_type = 0;
static const GEnumValue enum_values[] = {
{GST_RTPPASSTHROUGHPAY_RETIMESTAMP_MODE_DISABLED, "No retimestamping",
"disabled"},
{GST_RTPPASSTHROUGHPAY_RETIMESTAMP_MODE_ENABLED,
"Retimestamp based on PTS of each buffer", "enabled"},
{0, NULL, NULL},
};
if (!mode_type)
mode_type =
g_enum_register_static ("GstRtpPassthroughPayRetimestampMode",
enum_values);
return mode_type;
}
enum
{
PROP_0,
PROP_PT,
PROP_MTU,
PROP_STATS,
PROP_SEQNUM,
PROP_SEQNUM_OFFSET,
PROP_TIMESTAMP,
PROP_TIMESTAMP_OFFSET,
PROP_RETIMESTAMP_MODE,
};
static void gst_rtp_passthrough_pay_get_property (GObject * object,
guint prop_id, GValue * value, GParamSpec * pspec);
static void gst_rtp_passthrough_pay_set_property (GObject * object,
guint prop_id, const GValue * value, GParamSpec * pspec);
static void gst_rtp_passthrough_pay_finalize (GObject * object);
static GstStateChangeReturn
gst_rtp_passthrough_pay_change_state (GstElement * element,
GstStateChange transition);
static GstFlowReturn gst_rtp_passthrough_pay_chain (GstPad * pad,
GstObject * parent, GstBuffer * buffer);
static gboolean gst_rtp_passthrough_pay_sink_event (GstPad * pad,
GstObject * parent, GstEvent * event);
static void gst_rtp_passthrough_set_payload_type (GstRtpPassthroughPay * self,
guint pt);
static GstStructure
* gst_rtp_passthrough_pay_create_stats (GstRtpPassthroughPay * self);
static void
gst_rtp_passthrough_pay_init (GstRtpPassthroughPay * self)
{
self->sinkpad = gst_pad_new_from_static_template (&sink_template, "sink");
gst_pad_set_chain_function (self->sinkpad, gst_rtp_passthrough_pay_chain);
gst_pad_set_event_function (self->sinkpad,
gst_rtp_passthrough_pay_sink_event);
GST_OBJECT_FLAG_SET (self->sinkpad, GST_PAD_FLAG_PROXY_ALLOCATION);
GST_OBJECT_FLAG_SET (self->sinkpad, GST_PAD_FLAG_PROXY_CAPS);
GST_OBJECT_FLAG_SET (self->sinkpad, GST_PAD_FLAG_PROXY_SCHEDULING);
gst_element_add_pad (GST_ELEMENT (self), self->sinkpad);
self->srcpad = gst_pad_new_from_static_template (&src_template, "src");
GST_OBJECT_FLAG_SET (self->srcpad, GST_PAD_FLAG_PROXY_CAPS);
gst_element_add_pad (GST_ELEMENT (self), self->srcpad);
self->pt = PAYLOAD_TYPE_INVALID;
}
static void
gst_rtp_passthrough_pay_class_init (GstRtpPassthroughPayClass
* gst_rtp_passthrough_pay_class)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (gst_rtp_passthrough_pay_class);
GstElementClass *element_class =
GST_ELEMENT_CLASS (gst_rtp_passthrough_pay_class);
gobject_class->set_property = gst_rtp_passthrough_pay_set_property;
gobject_class->get_property = gst_rtp_passthrough_pay_get_property;
gobject_class->finalize = gst_rtp_passthrough_pay_finalize;
/**
* GstRtpPassthroughPay:pt:
*
* If set this will override the payload of the incoming RTP packets.
* If not set the payload type will be same as incoming RTP packets.
*
* Since: 1.24
*/
g_object_class_install_property (G_OBJECT_CLASS (gobject_class), PROP_PT,
g_param_spec_uint ("pt", "payload type",
"The payload type of the packets", 0, 0x80, PAYLOAD_TYPE_INVALID,
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
/**
* GstRtpPassthroughPay:mtu:
*
* Setting this property has no effect on this element, it is here and it
* is writable only to emulate a proper RTP payloader.
*
* Since: 1.24
*/
g_object_class_install_property (G_OBJECT_CLASS (gobject_class), PROP_MTU,
g_param_spec_uint ("mtu", "MTU", "Maximum size of one packet", 28,
G_MAXUINT, 1492, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
/**
* GstRtpPassthroughPay:timestamp:
*
* Since: 1.24
*/
g_object_class_install_property (G_OBJECT_CLASS (gobject_class),
PROP_TIMESTAMP, g_param_spec_uint ("timestamp", "Timestamp",
"The RTP timestamp of the last processed packet", 0, G_MAXUINT32, 0,
G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));
/**
* GstRtpPassthroughPay:seqnum:
*
* Since: 1.24
*/
g_object_class_install_property (G_OBJECT_CLASS (gobject_class), PROP_SEQNUM,
g_param_spec_uint ("seqnum", "Sequence number",
"The RTP sequence number of the last processed packet", 0,
G_MAXUINT16, 0, G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));
/**
* GstRtpPassthroughPay:timestamp-offset:
*
* Since: 1.24
*/
g_object_class_install_property (G_OBJECT_CLASS (gobject_class),
PROP_TIMESTAMP_OFFSET, g_param_spec_uint ("timestamp-offset",
"Timestamp Offset",
"Offset to add to all outgoing timestamps (default = random)", 0,
G_MAXUINT32, -1, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
/**
* GstRtpPassthroughPay:seqnum-offset:
*
* Since: 1.24
*/
g_object_class_install_property (G_OBJECT_CLASS (gobject_class),
PROP_SEQNUM_OFFSET, g_param_spec_int ("seqnum-offset",
"Sequence number Offset",
"Offset to add to all outgoing seqnum (-1 = random)", -1, G_MAXUINT16,
-1, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
/**
* GstRtpPassthroughPay:stats:
*
* Since: 1.24
*/
g_object_class_install_property (G_OBJECT_CLASS (gobject_class), PROP_STATS,
g_param_spec_boxed ("stats", "Statistics", "Various statistics",
GST_TYPE_STRUCTURE, G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));
/**
* GstRtpPassthroughPay:retimestamp-mode:
*
* If enabled, this mode will cause RTP timestamps to be re-generated
* based on the PTS of each processed buffer.
*
* Since: 1.26
*/
g_object_class_install_property (gobject_class, PROP_RETIMESTAMP_MODE,
g_param_spec_enum ("retimestamp-mode", "Retimestamp mode",
"RTP timestamp regeneration mode",
GST_RTPPASSTHROUGHPAY_RETIMESTAMP_MODE_TYPE,
GST_RTPPASSTHROUGHPAY_RETIMESTAMP_MODE_DISABLED,
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
element_class->change_state = gst_rtp_passthrough_pay_change_state;
gst_element_class_add_static_pad_template (element_class, &sink_template);
gst_element_class_add_static_pad_template (element_class, &src_template);
gst_element_class_set_static_metadata (element_class,
"RTP Passthrough payloader", "Codec/Payloader/Network/RTP",
"Passes through RTP packets",
"Sebastian Dröge <sebastian@centricular.com>, "
"Jonas Danielsson <jonas.danielsson@spiideo.com>");
GST_DEBUG_CATEGORY_INIT (gst_rtp_passthrough_pay_debug, "rtppassthroughpay",
0, "RTP Passthrough Payloader");
gst_type_mark_as_plugin_api (GST_RTPPASSTHROUGHPAY_RETIMESTAMP_MODE_TYPE, 0);
}
static void
gst_rtp_passthrough_pay_finalize (GObject * object)
{
GstRtpPassthroughPay *self = GST_RTP_PASSTHROUGH_PAY (object);
gst_clear_caps (&self->caps);
G_OBJECT_CLASS (gst_rtp_passthrough_pay_parent_class)->finalize (object);
}
static void
gst_rtp_passthrough_pay_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec)
{
GstRtpPassthroughPay *self = GST_RTP_PASSTHROUGH_PAY (object);
switch (prop_id) {
case PROP_PT:
g_value_set_uint (value, self->pt);
break;
case PROP_MTU:
g_value_set_uint (value, 0U);
break;
case PROP_TIMESTAMP:
g_value_set_uint (value, self->timestamp);
break;
case PROP_TIMESTAMP_OFFSET:
g_value_set_uint (value, self->timestamp_offset);
break;
case PROP_SEQNUM:
g_value_set_uint (value, self->seqnum);
break;
case PROP_SEQNUM_OFFSET:
g_value_set_int (value, (guint16) self->seqnum_offset);
break;
case PROP_STATS:
g_value_take_boxed (value, gst_rtp_passthrough_pay_create_stats (self));
break;
case PROP_RETIMESTAMP_MODE:
g_value_set_enum (value, self->retimestamp_mode);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gst_rtp_passthrough_pay_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec)
{
GstRtpPassthroughPay *self = GST_RTP_PASSTHROUGH_PAY (object);
switch (prop_id) {
case PROP_PT:
gst_rtp_passthrough_set_payload_type (self, g_value_get_uint (value));
break;
case PROP_MTU:
GST_WARNING_OBJECT (self, "Setting the mtu property has no effect");
break;
case PROP_TIMESTAMP_OFFSET:
GST_FIXME_OBJECT (self,
"Setting the timestamp-offset property has no effect");
break;
case PROP_SEQNUM_OFFSET:
GST_FIXME_OBJECT (self,
"Setting the seqnum-offset property has no effect");
break;
case PROP_RETIMESTAMP_MODE:
self->retimestamp_mode = g_value_get_enum (value);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static GstStateChangeReturn
gst_rtp_passthrough_pay_change_state (GstElement * element,
GstStateChange transition)
{
GstRtpPassthroughPay *self = GST_RTP_PASSTHROUGH_PAY (element);
GstStateChangeReturn ret;
ret = GST_ELEMENT_CLASS (gst_rtp_passthrough_pay_parent_class)
->change_state (element, transition);
switch (transition) {
case GST_STATE_CHANGE_PAUSED_TO_READY:
gst_clear_caps (&self->caps);
gst_segment_init (&self->segment, GST_FORMAT_TIME);
self->clock_rate = -1;
self->pt = PAYLOAD_TYPE_INVALID;
self->pt_override = FALSE;
self->ssrc = -1;
self->ssrc_set = FALSE;
self->timestamp = -1;
self->timestamp_offset = -1;
self->timestamp_offset_set = FALSE;
self->seqnum = -1;
self->pts_or_dts = GST_CLOCK_TIME_NONE;
break;
default:
break;
}
return ret;
}
static void
gst_rtppassthrough_pay_handle_retimestamp (GstRtpPassthroughPay * self,
GstRTPBuffer * rtp_buffer)
{
GstClockTime buf_pts = GST_BUFFER_PTS (rtp_buffer->buffer);
guint32 old_timestamp = gst_rtp_buffer_get_timestamp (rtp_buffer);
guint32 new_timestamp;
/* Code below is mostly borrowed from gst_rtp_base_payload_prepare_push() */
if (GST_CLOCK_TIME_IS_VALID (buf_pts)) {
guint64 rtime_hz, rtime_ns;
rtime_ns =
gst_segment_to_running_time (&self->segment, GST_FORMAT_TIME, buf_pts);
if (!GST_CLOCK_TIME_IS_VALID (rtime_ns)) {
GST_LOG_OBJECT (self, "Clipped pts, using base RTP timestamp");
rtime_hz = 0;
} else {
GST_LOG_OBJECT (self,
"Using running_time %" GST_TIME_FORMAT " for RTP timestamp",
GST_TIME_ARGS (rtime_ns));
rtime_hz =
gst_util_uint64_scale_int (rtime_ns, self->clock_rate, GST_SECOND);
}
/* add running_time in clock-rate units to the base timestamp */
new_timestamp = self->timestamp_offset + rtime_hz;
} else {
GST_LOG_OBJECT (self,
"Using previous RTP timestamp %" G_GUINT32_FORMAT, self->timestamp);
/* no timestamp to convert, take previous timestamp */
new_timestamp = self->timestamp;
}
GST_LOG_OBJECT (self, "Retimestamped from %u to %u", old_timestamp,
new_timestamp);
gst_rtp_buffer_set_timestamp (rtp_buffer, new_timestamp);
}
static GstFlowReturn
gst_rtp_passthrough_pay_chain (GstPad * pad,
GstObject * parent, GstBuffer * buffer)
{
GstRtpPassthroughPay *self = GST_RTP_PASSTHROUGH_PAY (parent);
GstRTPBuffer rtp_buffer = GST_RTP_BUFFER_INIT;
guint pt, ssrc, seqnum, timestamp;
buffer = gst_buffer_make_writable (buffer);
if (!gst_rtp_buffer_map (buffer, GST_MAP_READWRITE, &rtp_buffer)) {
GST_ERROR_OBJECT (self, "Invalid RTP buffer");
return gst_pad_push (self->srcpad, buffer);
}
/* If the PROP_PT property is set we override the incoming packets payload
* type. If it is not, we will mirror the payload type.
*
*/
pt = gst_rtp_buffer_get_payload_type (&rtp_buffer);
if (self->pt_override && self->pt != PAYLOAD_TYPE_INVALID) {
gst_rtp_buffer_set_payload_type (&rtp_buffer, self->pt);
} else {
if (pt != self->pt) {
if (self->pt != PAYLOAD_TYPE_INVALID) {
GST_WARNING_OBJECT (self, "Payload type changed from %u to %u",
self->pt, pt);
}
self->pt = pt;
g_object_notify (G_OBJECT (self), "pt");
}
}
ssrc = gst_rtp_buffer_get_ssrc (&rtp_buffer);
if (self->ssrc_set && self->ssrc != ssrc) {
GST_WARNING_OBJECT (self, "SSRC changed from %u to %u", self->ssrc, ssrc);
}
self->ssrc = ssrc;
self->ssrc_set = TRUE;
seqnum = gst_rtp_buffer_get_seq (&rtp_buffer);
self->seqnum = seqnum;
if (self->seqnum_offset == (guint) (-1)) {
self->seqnum_offset = seqnum;
g_object_notify (G_OBJECT (self), "seqnum-offset");
}
if (self->retimestamp_mode != GST_RTPPASSTHROUGHPAY_RETIMESTAMP_MODE_DISABLED) {
gst_rtppassthrough_pay_handle_retimestamp (self, &rtp_buffer);
}
timestamp = gst_rtp_buffer_get_timestamp (&rtp_buffer);
self->timestamp = timestamp;
if (!self->timestamp_offset_set) {
self->timestamp_offset = timestamp;
self->timestamp_offset_set = TRUE;
g_object_notify (G_OBJECT (self), "timestamp-offset");
}
gst_rtp_buffer_unmap (&rtp_buffer);
if (GST_BUFFER_PTS_IS_VALID (buffer))
self->pts_or_dts = GST_BUFFER_PTS (buffer);
else if (GST_BUFFER_DTS_IS_VALID (buffer))
self->pts_or_dts = GST_BUFFER_DTS (buffer);
return gst_pad_push (self->srcpad, buffer);
}
static gboolean
gst_rtp_passthrough_pay_sink_event (GstPad * pad,
GstObject * parent, GstEvent * event)
{
GstRtpPassthroughPay *self = GST_RTP_PASSTHROUGH_PAY (parent);
gboolean ret = FALSE;
switch (GST_EVENT_TYPE (event)) {
case GST_EVENT_SEGMENT:{
gst_event_copy_segment (event, &self->segment);
ret = gst_pad_event_default (pad, parent, event);
break;
}
case GST_EVENT_CAPS:{
GstCaps *caps;
const GstStructure *s;
gst_event_parse_caps (event, &caps);
gst_caps_replace (&self->caps, caps);
s = gst_caps_get_structure (caps, 0);
if (!self->pt_override
&& !gst_structure_get_int (s, "payload", &self->pt)) {
GST_WARNING_OBJECT (self, "Caps are missing payload type!");
}
if (!gst_structure_get_int (s, "clock-rate", &self->clock_rate))
GST_WARNING_OBJECT (self, "Caps are missing clock-rate!");
if (gst_structure_get_uint (s, "ssrc", &self->ssrc))
self->ssrc_set = TRUE;
if (gst_structure_get_uint (s, "clock-base", &self->timestamp_offset))
self->timestamp_offset_set = TRUE;
gst_structure_get_uint (s, "seqnum-base", &self->seqnum_offset);
ret = gst_pad_event_default (pad, parent, event);
break;
}
default:
ret = gst_pad_event_default (pad, parent, event);
break;
}
return ret;
}
static void
gst_rtp_passthrough_set_payload_type (GstRtpPassthroughPay * self, guint pt)
{
if (self->pt == pt) {
return;
}
if (pt != PAYLOAD_TYPE_INVALID) {
GST_INFO_OBJECT (self, "Overriding payload type (%u)", pt);
self->pt_override = TRUE;
} else {
self->pt_override = FALSE;
}
self->pt = pt;
}
static GstStructure *
gst_rtp_passthrough_pay_create_stats (GstRtpPassthroughPay * self)
{
GstClockTime running_time;
if (self->segment.format == GST_FORMAT_UNDEFINED) {
running_time = 0;
} else {
running_time = gst_segment_to_running_time (&self->segment, GST_FORMAT_TIME,
self->pts_or_dts);
}
return gst_structure_new ("application/x-rtp-payload-stats", "clock-rate",
G_TYPE_UINT, (guint) self->clock_rate, "running-time", G_TYPE_UINT64,
running_time, "seqnum", G_TYPE_UINT, (guint) self->seqnum, "timestamp",
G_TYPE_UINT, (guint) self->timestamp, "ssrc", G_TYPE_UINT, self->ssrc,
"pt", G_TYPE_UINT, self->pt, "seqnum-offset", G_TYPE_UINT,
(guint) self->seqnum_offset, "timestamp-offset", G_TYPE_UINT,
(guint) self->timestamp_offset, NULL);
return NULL;
}