gstreamer/gst/rtp/gstrtpgstdepay.c
Sebastian Dröge 44a697deba rtpgstdepay: Only store the current caps and drop old caps immediately
Otherwise it can happen that we already collected 7 caps, miss the 8th
caps packet (packet loss) and then re-use the 1st caps for the following
buffers instead of the 8th caps which will likely cause errors further
downstream unless both caps are accidentally the same.

Keeping old caps around does not seem to have any value other than
potentially causing errors. We would always receive new caps whenever
they change (even if they were previous ones) and it's very unlikely
that they happen to be exactly the same as the previous ones.

Also after having received new caps or a buffer with a next caps
version, no buffers with old caps version will arrive anymore.
2019-06-18 08:35:12 +00:00

612 lines
16 KiB
C

/* GStreamer
* Copyright (C) <2010> Wim Taymans <wim.taymans@gmail.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., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <string.h>
#include <stdlib.h>
#include "gstrtpgstdepay.h"
#include "gstrtputils.h"
#include <gst/video/video.h>
GST_DEBUG_CATEGORY_STATIC (rtpgstdepay_debug);
#define GST_CAT_DEFAULT (rtpgstdepay_debug)
static GstStaticPadTemplate gst_rtp_gst_depay_src_template =
GST_STATIC_PAD_TEMPLATE ("src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
GST_STATIC_CAPS_ANY);
static GstStaticPadTemplate gst_rtp_gst_depay_sink_template =
GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("application/x-rtp, "
"media = (string) \"application\", "
"clock-rate = (int) 90000, " "encoding-name = (string) \"X-GST\"")
);
#define gst_rtp_gst_depay_parent_class parent_class
G_DEFINE_TYPE (GstRtpGSTDepay, gst_rtp_gst_depay, GST_TYPE_RTP_BASE_DEPAYLOAD);
static void gst_rtp_gst_depay_finalize (GObject * object);
static gboolean gst_rtp_gst_depay_handle_event (GstRTPBaseDepayload * depay,
GstEvent * event);
static GstStateChangeReturn gst_rtp_gst_depay_change_state (GstElement *
element, GstStateChange transition);
static void gst_rtp_gst_depay_reset (GstRtpGSTDepay * rtpgstdepay, gboolean
full);
static gboolean gst_rtp_gst_depay_setcaps (GstRTPBaseDepayload * depayload,
GstCaps * caps);
static GstBuffer *gst_rtp_gst_depay_process (GstRTPBaseDepayload * depayload,
GstRTPBuffer * rtp);
static void
gst_rtp_gst_depay_class_init (GstRtpGSTDepayClass * klass)
{
GObjectClass *gobject_class;
GstElementClass *gstelement_class;
GstRTPBaseDepayloadClass *gstrtpbasedepayload_class;
GST_DEBUG_CATEGORY_INIT (rtpgstdepay_debug, "rtpgstdepay", 0,
"Gstreamer RTP Depayloader");
gobject_class = (GObjectClass *) klass;
gstelement_class = (GstElementClass *) klass;
gstrtpbasedepayload_class = (GstRTPBaseDepayloadClass *) klass;
gobject_class->finalize = gst_rtp_gst_depay_finalize;
gstelement_class->change_state = gst_rtp_gst_depay_change_state;
gst_element_class_add_static_pad_template (gstelement_class,
&gst_rtp_gst_depay_src_template);
gst_element_class_add_static_pad_template (gstelement_class,
&gst_rtp_gst_depay_sink_template);
gst_element_class_set_static_metadata (gstelement_class,
"GStreamer depayloader", "Codec/Depayloader/Network",
"Extracts GStreamer buffers from RTP packets",
"Wim Taymans <wim.taymans@gmail.com>");
gstrtpbasedepayload_class->handle_event = gst_rtp_gst_depay_handle_event;
gstrtpbasedepayload_class->set_caps = gst_rtp_gst_depay_setcaps;
gstrtpbasedepayload_class->process_rtp_packet = gst_rtp_gst_depay_process;
}
static void
gst_rtp_gst_depay_init (GstRtpGSTDepay * rtpgstdepay)
{
rtpgstdepay->adapter = gst_adapter_new ();
}
static void
gst_rtp_gst_depay_finalize (GObject * object)
{
GstRtpGSTDepay *rtpgstdepay;
rtpgstdepay = GST_RTP_GST_DEPAY (object);
gst_rtp_gst_depay_reset (rtpgstdepay, TRUE);
g_object_unref (rtpgstdepay->adapter);
G_OBJECT_CLASS (parent_class)->finalize (object);
}
static void
gst_rtp_gst_depay_reset (GstRtpGSTDepay * rtpgstdepay, gboolean full)
{
gst_adapter_clear (rtpgstdepay->adapter);
if (full) {
rtpgstdepay->current_CV = 0;
gst_caps_replace (&rtpgstdepay->current_caps, NULL);
g_free (rtpgstdepay->stream_id);
rtpgstdepay->stream_id = NULL;
if (rtpgstdepay->tags)
gst_tag_list_unref (rtpgstdepay->tags);
rtpgstdepay->tags = NULL;
}
}
static gboolean
gst_rtp_gst_depay_setcaps (GstRTPBaseDepayload * depayload, GstCaps * caps)
{
GstRtpGSTDepay *rtpgstdepay;
GstStructure *structure;
gint clock_rate;
gboolean res;
const gchar *capsenc;
rtpgstdepay = GST_RTP_GST_DEPAY (depayload);
structure = gst_caps_get_structure (caps, 0);
if (!gst_structure_get_int (structure, "clock-rate", &clock_rate))
clock_rate = 90000;
depayload->clock_rate = clock_rate;
capsenc = gst_structure_get_string (structure, "caps");
if (capsenc) {
GstCaps *outcaps;
gsize out_len;
gchar *capsstr;
const gchar *capsver;
guint CV;
/* decode caps */
capsstr = (gchar *) g_base64_decode (capsenc, &out_len);
outcaps = gst_caps_from_string (capsstr);
g_free (capsstr);
/* parse version */
capsver = gst_structure_get_string (structure, "capsversion");
if (capsver) {
CV = atoi (capsver);
} else {
/* no version, assume 0 */
CV = 0;
}
/* store in cache */
rtpgstdepay->current_CV = CV;
gst_caps_replace (&rtpgstdepay->current_caps, outcaps);
res = gst_pad_set_caps (depayload->srcpad, outcaps);
gst_caps_unref (outcaps);
} else {
GST_WARNING_OBJECT (depayload, "no caps given");
rtpgstdepay->current_CV = -1;
gst_caps_replace (&rtpgstdepay->current_caps, NULL);
res = TRUE;
}
return res;
}
static gboolean
read_length (GstRtpGSTDepay * rtpgstdepay, guint8 * data, guint size,
guint * length, guint * skip)
{
guint b, len, offset;
/* start reading the length, we need this to skip to the data later */
len = offset = 0;
do {
if (offset >= size)
return FALSE;
b = data[offset++];
len = (len << 7) | (b & 0x7f);
} while (b & 0x80);
/* check remaining buffer size */
if (size - offset < len)
return FALSE;
*length = len;
*skip = offset;
return TRUE;
}
static GstCaps *
read_caps (GstRtpGSTDepay * rtpgstdepay, GstBuffer * buf, guint * skip)
{
guint offset, length;
GstCaps *caps;
GstMapInfo map;
gst_buffer_map (buf, &map, GST_MAP_READ);
GST_DEBUG_OBJECT (rtpgstdepay, "buffer size %" G_GSIZE_FORMAT, map.size);
if (!read_length (rtpgstdepay, map.data, map.size, &length, &offset))
goto too_small;
if (length == 0 || map.data[offset + length - 1] != '\0')
goto invalid_buffer;
GST_DEBUG_OBJECT (rtpgstdepay, "parsing caps %s", &map.data[offset]);
/* parse and store in cache */
caps = gst_caps_from_string ((gchar *) & map.data[offset]);
gst_buffer_unmap (buf, &map);
*skip = length + offset;
return caps;
too_small:
{
GST_ELEMENT_WARNING (rtpgstdepay, STREAM, DECODE,
("Buffer too small."), (NULL));
gst_buffer_unmap (buf, &map);
return NULL;
}
invalid_buffer:
{
GST_ELEMENT_WARNING (rtpgstdepay, STREAM, DECODE,
("caps string not 0-terminated."), (NULL));
gst_buffer_unmap (buf, &map);
return NULL;
}
}
static GstEvent *
read_event (GstRtpGSTDepay * rtpgstdepay, guint type,
GstBuffer * buf, guint * skip)
{
guint offset, length;
GstStructure *s;
GstEvent *event;
GstEventType etype;
gchar *end;
GstMapInfo map;
gst_buffer_map (buf, &map, GST_MAP_READ);
GST_DEBUG_OBJECT (rtpgstdepay, "buffer size %" G_GSIZE_FORMAT, map.size);
if (!read_length (rtpgstdepay, map.data, map.size, &length, &offset))
goto too_small;
if (length == 0)
goto invalid_buffer;
/* backward compat, old payloader did not put 0-byte at the end */
if (map.data[offset + length - 1] != '\0'
&& map.data[offset + length - 1] != ';')
goto invalid_buffer;
GST_DEBUG_OBJECT (rtpgstdepay, "parsing event %s", &map.data[offset]);
/* parse */
s = gst_structure_from_string ((gchar *) & map.data[offset], &end);
gst_buffer_unmap (buf, &map);
if (s == NULL)
goto parse_failed;
switch (type) {
case 1:
etype = GST_EVENT_TAG;
break;
case 2:
etype = GST_EVENT_CUSTOM_DOWNSTREAM;
break;
case 3:
etype = GST_EVENT_CUSTOM_BOTH;
break;
case 4:
etype = GST_EVENT_STREAM_START;
break;
default:
goto unknown_event;
}
event = gst_event_new_custom (etype, s);
*skip = length + offset;
return event;
too_small:
{
GST_ELEMENT_WARNING (rtpgstdepay, STREAM, DECODE,
("Buffer too small."), (NULL));
gst_buffer_unmap (buf, &map);
return NULL;
}
invalid_buffer:
{
GST_ELEMENT_WARNING (rtpgstdepay, STREAM, DECODE,
("event string not 0-terminated."), (NULL));
gst_buffer_unmap (buf, &map);
return NULL;
}
parse_failed:
{
GST_WARNING_OBJECT (rtpgstdepay, "could not parse event");
return NULL;
}
unknown_event:
{
GST_DEBUG_OBJECT (rtpgstdepay, "unknown event type");
gst_structure_free (s);
return NULL;
}
}
static void
store_event (GstRtpGSTDepay * rtpgstdepay, GstEvent * event)
{
gboolean do_push = FALSE;
switch (GST_EVENT_TYPE (event)) {
case GST_EVENT_TAG:
{
GstTagList *old, *tags;
gst_event_parse_tag (event, &tags);
old = rtpgstdepay->tags;
if (!old || !gst_tag_list_is_equal (old, tags)) {
do_push = TRUE;
if (old)
gst_tag_list_unref (old);
rtpgstdepay->tags = gst_tag_list_ref (tags);
}
break;
}
case GST_EVENT_CUSTOM_DOWNSTREAM:
case GST_EVENT_CUSTOM_BOTH:
/* always push custom events */
do_push = TRUE;
break;
case GST_EVENT_STREAM_START:
{
gchar *old;
const gchar *stream_id = NULL;
gst_event_parse_stream_start (event, &stream_id);
old = rtpgstdepay->stream_id;
if (!old || g_strcmp0 (old, stream_id)) {
do_push = TRUE;
g_free (old);
rtpgstdepay->stream_id = g_strdup (stream_id);
}
break;
}
default:
/* unknown event, don't push */
break;
}
if (do_push)
gst_pad_push_event (GST_RTP_BASE_DEPAYLOAD (rtpgstdepay)->srcpad, event);
else
gst_event_unref (event);
}
static GstBuffer *
gst_rtp_gst_depay_process (GstRTPBaseDepayload * depayload, GstRTPBuffer * rtp)
{
GstRtpGSTDepay *rtpgstdepay;
GstBuffer *subbuf, *outbuf = NULL;
gint payload_len;
guint8 *payload;
guint CV, frag_offset, avail, offset;
rtpgstdepay = GST_RTP_GST_DEPAY (depayload);
payload_len = gst_rtp_buffer_get_payload_len (rtp);
if (payload_len <= 8)
goto empty_packet;
if (GST_BUFFER_IS_DISCONT (rtp->buffer)) {
GST_WARNING_OBJECT (rtpgstdepay, "DISCONT, clear adapter");
gst_adapter_clear (rtpgstdepay->adapter);
}
payload = gst_rtp_buffer_get_payload (rtp);
/* strip off header
*
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* |C| CV |D|0|0|0| ETYPE | MBZ |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Frag_offset |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
frag_offset =
(payload[4] << 24) | (payload[5] << 16) | (payload[6] << 8) | payload[7];
avail = gst_adapter_available (rtpgstdepay->adapter);
if (avail != frag_offset)
goto wrong_frag;
/* subbuffer skipping the 8 header bytes */
subbuf = gst_rtp_buffer_get_payload_subbuffer (rtp, 8, -1);
gst_adapter_push (rtpgstdepay->adapter, subbuf);
offset = 0;
if (gst_rtp_buffer_get_marker (rtp)) {
guint avail;
GstCaps *outcaps;
/* take the buffer */
avail = gst_adapter_available (rtpgstdepay->adapter);
outbuf = gst_adapter_take_buffer (rtpgstdepay->adapter, avail);
CV = (payload[0] >> 4) & 0x7;
if (payload[0] & 0x80) {
guint size;
/* C bit, we have inline caps */
outcaps = read_caps (rtpgstdepay, outbuf, &size);
if (outcaps == NULL)
goto no_caps;
GST_DEBUG_OBJECT (rtpgstdepay,
"inline caps %u, length %u, %" GST_PTR_FORMAT, CV, size, outcaps);
if (!rtpgstdepay->current_caps
|| !gst_caps_is_strictly_equal (rtpgstdepay->current_caps, outcaps))
gst_pad_set_caps (depayload->srcpad, outcaps);
gst_caps_replace (&rtpgstdepay->current_caps, outcaps);
gst_caps_unref (outcaps);
rtpgstdepay->current_CV = CV;
/* skip caps */
offset += size;
avail -= size;
}
if (payload[1]) {
guint size;
GstEvent *event;
/* we have an event */
event = read_event (rtpgstdepay, payload[1], outbuf, &size);
if (event == NULL)
goto no_event;
GST_DEBUG_OBJECT (rtpgstdepay,
"inline event, length %u, %" GST_PTR_FORMAT, size, event);
store_event (rtpgstdepay, event);
/* no buffer after event */
avail = 0;
}
if (avail) {
if (offset != 0) {
GstBuffer *temp;
GST_DEBUG_OBJECT (rtpgstdepay, "sub buffer: offset %u, size %u", offset,
avail);
temp =
gst_buffer_copy_region (outbuf, GST_BUFFER_COPY_ALL, offset, avail);
gst_buffer_unref (outbuf);
outbuf = temp;
}
/* see what caps we need */
if (CV != rtpgstdepay->current_CV) {
/* we need to switch caps but didn't receive the new caps yet */
gst_caps_replace (&rtpgstdepay->current_caps, NULL);
goto missing_caps;
}
if (payload[0] & 0x8)
GST_BUFFER_FLAG_SET (outbuf, GST_BUFFER_FLAG_DELTA_UNIT);
} else {
gst_buffer_unref (outbuf);
outbuf = NULL;
}
}
if (outbuf) {
gst_rtp_drop_meta (GST_ELEMENT_CAST (rtpgstdepay), outbuf, 0);
}
return outbuf;
/* ERRORS */
empty_packet:
{
GST_ELEMENT_WARNING (rtpgstdepay, STREAM, DECODE,
("Empty Payload."), (NULL));
return NULL;
}
wrong_frag:
{
gst_adapter_clear (rtpgstdepay->adapter);
GST_LOG_OBJECT (rtpgstdepay, "wrong fragment, skipping");
return NULL;
}
no_caps:
{
GST_WARNING_OBJECT (rtpgstdepay, "failed to parse caps");
gst_buffer_unref (outbuf);
return NULL;
}
no_event:
{
GST_WARNING_OBJECT (rtpgstdepay, "failed to parse event");
gst_buffer_unref (outbuf);
return NULL;
}
missing_caps:
{
GST_INFO_OBJECT (rtpgstdepay, "No caps received yet %u", CV);
gst_buffer_unref (outbuf);
gst_pad_push_event (GST_RTP_BASE_DEPAYLOAD_SINKPAD (rtpgstdepay),
gst_video_event_new_upstream_force_key_unit (GST_CLOCK_TIME_NONE,
TRUE, 0));
return NULL;
}
}
static gboolean
gst_rtp_gst_depay_handle_event (GstRTPBaseDepayload * depay, GstEvent * event)
{
GstRtpGSTDepay *rtpgstdepay;
rtpgstdepay = GST_RTP_GST_DEPAY (depay);
switch (GST_EVENT_TYPE (event)) {
case GST_EVENT_FLUSH_STOP:
gst_rtp_gst_depay_reset (rtpgstdepay, FALSE);
break;
default:
break;
}
return
GST_RTP_BASE_DEPAYLOAD_CLASS (parent_class)->handle_event (depay, event);
}
static GstStateChangeReturn
gst_rtp_gst_depay_change_state (GstElement * element, GstStateChange transition)
{
GstRtpGSTDepay *rtpgstdepay;
GstStateChangeReturn ret;
rtpgstdepay = GST_RTP_GST_DEPAY (element);
switch (transition) {
case GST_STATE_CHANGE_READY_TO_PAUSED:
gst_rtp_gst_depay_reset (rtpgstdepay, TRUE);
break;
default:
break;
}
ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
switch (transition) {
case GST_STATE_CHANGE_PAUSED_TO_READY:
gst_rtp_gst_depay_reset (rtpgstdepay, TRUE);
break;
default:
break;
}
return ret;
}
gboolean
gst_rtp_gst_depay_plugin_init (GstPlugin * plugin)
{
return gst_element_register (plugin, "rtpgstdepay",
GST_RANK_MARGINAL, GST_TYPE_RTP_GST_DEPAY);
}