gstreamer/gst/rtp/gstrtpvp9depay.c
2021-03-29 12:45:22 +02:00

528 lines
17 KiB
C

/* gstrtpvp9depay.c - Source for GstRtpVP9Depay
* Copyright (C) 2011 Sjoerd Simons <sjoerd@luon.net>
* Copyright (C) 2011 Collabora Ltd.
* Contact: Youness Alaoui <youness.alaoui@collabora.co.uk>
* Copyright (C) 2015 Stian Selnes <stian@pexip.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser 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 "gstrtpelements.h"
#include "gstrtpvp9depay.h"
#include "gstrtputils.h"
#include <gst/video/video.h>
#include <stdio.h>
GST_DEBUG_CATEGORY_STATIC (gst_rtp_vp9_depay_debug);
#define GST_CAT_DEFAULT gst_rtp_vp9_depay_debug
static void gst_rtp_vp9_depay_dispose (GObject * object);
static GstBuffer *gst_rtp_vp9_depay_process (GstRTPBaseDepayload * depayload,
GstRTPBuffer * rtp);
static GstStateChangeReturn gst_rtp_vp9_depay_change_state (GstElement *
element, GstStateChange transition);
static gboolean gst_rtp_vp9_depay_handle_event (GstRTPBaseDepayload * depay,
GstEvent * event);
static gboolean gst_rtp_vp9_depay_packet_lost (GstRTPBaseDepayload * depay,
GstEvent * event);
G_DEFINE_TYPE (GstRtpVP9Depay, gst_rtp_vp9_depay, GST_TYPE_RTP_BASE_DEPAYLOAD);
GST_ELEMENT_REGISTER_DEFINE_WITH_CODE (rtpvp9depay, "rtpvp9depay",
GST_RANK_MARGINAL, GST_TYPE_RTP_VP9_DEPAY, rtp_element_init (plugin));
static GstStaticPadTemplate gst_rtp_vp9_depay_src_template =
GST_STATIC_PAD_TEMPLATE ("src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("video/x-vp9"));
static GstStaticPadTemplate gst_rtp_vp9_depay_sink_template =
GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("application/x-rtp, "
"clock-rate = (int) 90000,"
"media = (string) \"video\","
"encoding-name = (string) { \"VP9\", \"VP9-DRAFT-IETF-01\" }"));
#define PICTURE_ID_NONE (UINT_MAX)
#define IS_PICTURE_ID_15BITS(pid) (((guint)(pid) & 0x8000) != 0)
static void
gst_rtp_vp9_depay_init (GstRtpVP9Depay * self)
{
self->adapter = gst_adapter_new ();
self->started = FALSE;
self->inter_picture = FALSE;
}
static void
gst_rtp_vp9_depay_class_init (GstRtpVP9DepayClass * gst_rtp_vp9_depay_class)
{
GObjectClass *object_class = G_OBJECT_CLASS (gst_rtp_vp9_depay_class);
GstElementClass *element_class = GST_ELEMENT_CLASS (gst_rtp_vp9_depay_class);
GstRTPBaseDepayloadClass *depay_class =
(GstRTPBaseDepayloadClass *) (gst_rtp_vp9_depay_class);
gst_element_class_add_static_pad_template (element_class,
&gst_rtp_vp9_depay_sink_template);
gst_element_class_add_static_pad_template (element_class,
&gst_rtp_vp9_depay_src_template);
gst_element_class_set_static_metadata (element_class, "RTP VP9 depayloader",
"Codec/Depayloader/Network/RTP",
"Extracts VP9 video from RTP packets)", "Stian Selnes <stian@pexip.com>");
object_class->dispose = gst_rtp_vp9_depay_dispose;
element_class->change_state = gst_rtp_vp9_depay_change_state;
depay_class->process_rtp_packet = gst_rtp_vp9_depay_process;
depay_class->handle_event = gst_rtp_vp9_depay_handle_event;
depay_class->packet_lost = gst_rtp_vp9_depay_packet_lost;
GST_DEBUG_CATEGORY_INIT (gst_rtp_vp9_depay_debug, "rtpvp9depay", 0,
"VP9 Video RTP Depayloader");
}
static void
gst_rtp_vp9_depay_dispose (GObject * object)
{
GstRtpVP9Depay *self = GST_RTP_VP9_DEPAY (object);
if (self->adapter != NULL)
g_object_unref (self->adapter);
self->adapter = NULL;
/* release any references held by the object here */
if (G_OBJECT_CLASS (gst_rtp_vp9_depay_parent_class)->dispose)
G_OBJECT_CLASS (gst_rtp_vp9_depay_parent_class)->dispose (object);
}
static gint
picture_id_compare (guint16 id0, guint16 id1)
{
guint shift = 16 - (IS_PICTURE_ID_15BITS (id1) ? 15 : 7);
id0 = id0 << shift;
id1 = id1 << shift;
return ((gint16) (id1 - id0)) >> shift;
}
static void
send_last_lost_event (GstRtpVP9Depay * self)
{
if (self->last_lost_event) {
GST_DEBUG_OBJECT (self,
"Sending the last stopped lost event: %" GST_PTR_FORMAT,
self->last_lost_event);
GST_RTP_BASE_DEPAYLOAD_CLASS (gst_rtp_vp9_depay_parent_class)
->packet_lost (GST_RTP_BASE_DEPAYLOAD_CAST (self),
self->last_lost_event);
gst_event_replace (&self->last_lost_event, NULL);
}
}
static void
send_last_lost_event_if_needed (GstRtpVP9Depay * self, guint new_picture_id)
{
if (self->last_picture_id == PICTURE_ID_NONE ||
self->last_picture_id == new_picture_id)
return;
if (self->last_lost_event) {
gboolean send_lost_event = FALSE;
if (new_picture_id == PICTURE_ID_NONE) {
GST_DEBUG_OBJECT (self, "Dropping the last stopped lost event "
"(picture id does not exist): %" GST_PTR_FORMAT,
self->last_lost_event);
} else if (IS_PICTURE_ID_15BITS (self->last_picture_id) &&
!IS_PICTURE_ID_15BITS (new_picture_id)) {
GST_DEBUG_OBJECT (self, "Dropping the last stopped lost event "
"(picture id has less bits than before): %" GST_PTR_FORMAT,
self->last_lost_event);
} else if (picture_id_compare (self->last_picture_id, new_picture_id) != 1) {
GstStructure *s = gst_event_writable_structure (self->last_lost_event);
GST_DEBUG_OBJECT (self, "Sending the last stopped lost event "
"(gap in picture id %u %u): %" GST_PTR_FORMAT,
self->last_picture_id, new_picture_id, self->last_lost_event);
send_lost_event = TRUE;
/* Prevent rtpbasedepayload from dropping the event now
* that we have made sure the lost packet was not FEC */
gst_structure_remove_field (s, "might-have-been-fec");
}
if (send_lost_event)
GST_RTP_BASE_DEPAYLOAD_CLASS (gst_rtp_vp9_depay_parent_class)
->packet_lost (GST_RTP_BASE_DEPAYLOAD_CAST (self),
self->last_lost_event);
gst_event_replace (&self->last_lost_event, NULL);
}
}
static GstBuffer *
gst_rtp_vp9_depay_process (GstRTPBaseDepayload * depay, GstRTPBuffer * rtp)
{
GstRtpVP9Depay *self = GST_RTP_VP9_DEPAY (depay);
GstBuffer *payload;
guint8 *data;
guint hdrsize = 1;
guint size;
gint spatial_layer = 0;
guint picture_id = PICTURE_ID_NONE;
gboolean i_bit, p_bit, l_bit, f_bit, b_bit, e_bit, v_bit, d_bit = 0;
gboolean is_start_of_picture;
if (G_UNLIKELY (GST_BUFFER_IS_DISCONT (rtp->buffer))) {
GST_LOG_OBJECT (self, "Discontinuity, flushing adapter");
gst_adapter_clear (self->adapter);
self->started = FALSE;
}
size = gst_rtp_buffer_get_payload_len (rtp);
/* Mandatory with at least one header and one vp9 byte */
if (G_UNLIKELY (size < hdrsize + 1))
goto too_small;
data = gst_rtp_buffer_get_payload (rtp);
i_bit = (data[0] & 0x80) != 0;
p_bit = (data[0] & 0x40) != 0;
l_bit = (data[0] & 0x20) != 0;
f_bit = (data[0] & 0x10) != 0;
b_bit = (data[0] & 0x08) != 0;
e_bit = (data[0] & 0x04) != 0;
v_bit = (data[0] & 0x02) != 0;
GST_TRACE_OBJECT (self, "IPLFBEV : %d%d%d%d%d%d%d", i_bit, p_bit, l_bit,
f_bit, b_bit, e_bit, v_bit);
/* Check I optional header Picture ID */
if (i_bit) {
hdrsize++;
if (G_UNLIKELY (size < hdrsize + 1))
goto too_small;
picture_id = data[1];
/* Check M for 15 bits PictureID */
if ((data[1] & 0x80) != 0) {
hdrsize++;
if (G_UNLIKELY (size < hdrsize + 1))
goto too_small;
picture_id = (picture_id << 8) | data[2];
}
}
/* Check L optional header layer indices */
if (l_bit) {
spatial_layer = (data[hdrsize] >> 1) & 0x07;
d_bit = (data[hdrsize] >> 0) & 0x01;
GST_TRACE_OBJECT (self, "TID=%d, U=%d, SID=%d, D=%d",
(data[hdrsize] >> 5) & 0x07, (data[hdrsize] >> 4) & 0x01,
(data[hdrsize] >> 1) & 0x07, (data[hdrsize] >> 0) & 0x01);
if (spatial_layer == 0 && d_bit != 0) {
/* Invalid according to draft-ietf-payload-vp9-06, but firefox 61 and
* chrome 66 sends enchanment layers with SID=0, so let's not drop the
* packet. */
GST_LOG_OBJECT (self, "Invalid inter-layer dependency for base layer");
}
hdrsize++;
/* Check TL0PICIDX temporal layer zero index (non-flexible mode) */
if (!f_bit)
hdrsize++;
}
if (p_bit && f_bit) {
gint i;
/* At least one P_DIFF|N, up to three times */
for (i = 0; i < 3; i++) {
guint p_diff, n_bit;
if (G_UNLIKELY (size < hdrsize + 1))
goto too_small;
p_diff = data[hdrsize] >> 1;
n_bit = data[hdrsize] & 0x1;
GST_TRACE_OBJECT (self, "P_DIFF[%d]=%d", i, p_diff);
hdrsize++;
if (!n_bit)
break;
}
}
/* Check V optional Scalability Structure */
if (v_bit) {
guint n_s, y_bit, g_bit;
guint8 *ss = &data[hdrsize];
guint sssize = 1;
if (G_UNLIKELY (size < hdrsize + sssize + 1))
goto too_small;
n_s = (ss[0] & 0xe0) >> 5;
y_bit = (ss[0] & 0x10) != 0;
g_bit = (ss[0] & 0x08) != 0;
GST_TRACE_OBJECT (self, "SS header: N_S=%u, Y=%u, G=%u", n_s, y_bit, g_bit);
sssize += y_bit ? (n_s + 1) * 4 : 0;
if (G_UNLIKELY (size < hdrsize + sssize + 1))
goto too_small;
if (y_bit) {
guint i;
for (i = 0; i <= n_s; i++) {
/* For now, simply use the last layer specified for width and height */
self->ss_width = ss[1 + i * 4] * 256 + ss[2 + i * 4];
self->ss_height = ss[3 + i * 4] * 256 + ss[4 + i * 4];
GST_TRACE_OBJECT (self, "N_S[%d]: WIDTH=%u, HEIGHT=%u", i,
self->ss_width, self->ss_height);
}
}
if (g_bit) {
guint i, j;
guint n_g = ss[sssize];
sssize++;
if (G_UNLIKELY (size < hdrsize + sssize + 1))
goto too_small;
for (i = 0; i < n_g; i++) {
guint t = (ss[sssize] & 0xe0) >> 5;
guint u = (ss[sssize] & 0x10) >> 4;
guint r = (ss[sssize] & 0x0c) >> 2;
GST_TRACE_OBJECT (self, "N_G[%u]: 0x%02x -> T=%u, U=%u, R=%u", i,
ss[sssize], t, u, r);
for (j = 0; j < r; j++)
GST_TRACE_OBJECT (self, " R[%u]: P_DIFF=%u", j, ss[sssize + 1 + j]);
sssize += 1 + r;
if (G_UNLIKELY (size < hdrsize + sssize + 1))
goto too_small;
}
}
hdrsize += sssize;
}
GST_DEBUG_OBJECT (depay, "hdrsize %u, size %u, picture id 0x%x",
hdrsize, size, picture_id);
if (G_UNLIKELY (hdrsize >= size))
goto too_small;
is_start_of_picture = b_bit && (!l_bit || !d_bit);
/* If this is a start frame AND we are already processing a frame, we need to flush and wait for next start frame */
if (is_start_of_picture) {
if (G_UNLIKELY (self->started)) {
GST_DEBUG_OBJECT (depay, "Incomplete frame, flushing adapter");
gst_adapter_clear (self->adapter);
self->started = FALSE;
}
}
if (G_UNLIKELY (!self->started)) {
/* Check if this is the start of a VP9 layer frame, otherwise bail */
if (!b_bit) {
GST_DEBUG_OBJECT (depay,
"The layer is missing the first packets, ignoring the packet");
if (self->stop_lost_events) {
send_last_lost_event (self);
self->stop_lost_events = FALSE;
}
goto done;
}
GST_DEBUG_OBJECT (depay, "Found the start of the layer");
if (self->stop_lost_events) {
send_last_lost_event_if_needed (self, picture_id);
self->stop_lost_events = FALSE;
}
self->started = TRUE;
self->inter_picture = FALSE;
}
payload = gst_rtp_buffer_get_payload_subbuffer (rtp, hdrsize, -1);
if (GST_LEVEL_MEMDUMP <= gst_debug_category_get_threshold (GST_CAT_DEFAULT)) {
GstMapInfo map;
gst_buffer_map (payload, &map, GST_MAP_READ);
GST_MEMDUMP_OBJECT (self, "vp9 payload", map.data, 16);
gst_buffer_unmap (payload, &map);
}
gst_adapter_push (self->adapter, payload);
self->last_picture_id = picture_id;
self->inter_picture |= p_bit;
/* Marker indicates that it was the last rtp packet for this picture. Note
* that if spatial scalability is used, e_bit will be set for the last
* packet of a frame while the marker bit is not set until the last packet
* of the picture. */
if (gst_rtp_buffer_get_marker (rtp)) {
GstBuffer *out;
GST_DEBUG_OBJECT (depay,
"Found the end of the frame (%" G_GSIZE_FORMAT " bytes)",
gst_adapter_available (self->adapter));
if (gst_adapter_available (self->adapter) < 10)
goto too_small;
out = gst_adapter_take_buffer (self->adapter,
gst_adapter_available (self->adapter));
self->started = FALSE;
/* mark keyframes */
out = gst_buffer_make_writable (out);
/* Filter away all metas that are not sensible to copy */
gst_rtp_drop_non_video_meta (self, out);
if (self->inter_picture) {
GST_BUFFER_FLAG_SET (out, GST_BUFFER_FLAG_DELTA_UNIT);
if (!self->caps_sent) {
gst_buffer_unref (out);
out = NULL;
GST_INFO_OBJECT (self, "Dropping inter-frame before intra-frame");
gst_pad_push_event (GST_RTP_BASE_DEPAYLOAD_SINKPAD (depay),
gst_video_event_new_upstream_force_key_unit (GST_CLOCK_TIME_NONE,
TRUE, 0));
}
} else {
GST_BUFFER_FLAG_UNSET (out, GST_BUFFER_FLAG_DELTA_UNIT);
if (self->last_width != self->ss_width ||
self->last_height != self->ss_height) {
GstCaps *srccaps;
/* Width and height are optional in the RTP header. Consider to parse
* the frame header in addition if missing from RTP header */
if (self->ss_width != 0 && self->ss_height != 0) {
srccaps = gst_caps_new_simple ("video/x-vp9",
"framerate", GST_TYPE_FRACTION, 0, 1,
"width", G_TYPE_INT, self->ss_width,
"height", G_TYPE_INT, self->ss_height, NULL);
} else {
srccaps = gst_caps_new_simple ("video/x-vp9",
"framerate", GST_TYPE_FRACTION, 0, 1, NULL);
}
gst_pad_set_caps (GST_RTP_BASE_DEPAYLOAD_SRCPAD (depay), srccaps);
gst_caps_unref (srccaps);
self->caps_sent = TRUE;
self->last_width = self->ss_width;
self->last_height = self->ss_height;
self->ss_width = 0;
self->ss_height = 0;
}
}
if (picture_id != PICTURE_ID_NONE)
self->stop_lost_events = TRUE;
return out;
}
done:
return NULL;
too_small:
GST_LOG_OBJECT (self, "Invalid rtp packet (too small), ignoring");
gst_adapter_clear (self->adapter);
self->started = FALSE;
goto done;
}
static GstStateChangeReturn
gst_rtp_vp9_depay_change_state (GstElement * element, GstStateChange transition)
{
GstRtpVP9Depay *self = GST_RTP_VP9_DEPAY (element);
switch (transition) {
case GST_STATE_CHANGE_READY_TO_PAUSED:
self->last_width = -1;
self->last_height = -1;
self->caps_sent = FALSE;
self->last_picture_id = PICTURE_ID_NONE;
gst_event_replace (&self->last_lost_event, NULL);
self->stop_lost_events = FALSE;
break;
default:
break;
}
return
GST_ELEMENT_CLASS (gst_rtp_vp9_depay_parent_class)->change_state (element,
transition);
}
static gboolean
gst_rtp_vp9_depay_handle_event (GstRTPBaseDepayload * depay, GstEvent * event)
{
GstRtpVP9Depay *self = GST_RTP_VP9_DEPAY (depay);
switch (GST_EVENT_TYPE (event)) {
case GST_EVENT_FLUSH_STOP:
self->last_width = -1;
self->last_height = -1;
self->last_picture_id = PICTURE_ID_NONE;
gst_event_replace (&self->last_lost_event, NULL);
self->stop_lost_events = FALSE;
break;
default:
break;
}
return
GST_RTP_BASE_DEPAYLOAD_CLASS
(gst_rtp_vp9_depay_parent_class)->handle_event (depay, event);
}
static gboolean
gst_rtp_vp9_depay_packet_lost (GstRTPBaseDepayload * depay, GstEvent * event)
{
GstRtpVP9Depay *self = GST_RTP_VP9_DEPAY (depay);
const GstStructure *s;
gboolean might_have_been_fec;
s = gst_event_get_structure (event);
if (self->stop_lost_events) {
if (gst_structure_get_boolean (s, "might-have-been-fec",
&might_have_been_fec)
&& might_have_been_fec) {
GST_DEBUG_OBJECT (depay, "Stopping lost event %" GST_PTR_FORMAT, event);
gst_event_replace (&self->last_lost_event, event);
return TRUE;
}
} else if (self->last_picture_id != PICTURE_ID_NONE) {
GstStructure *s = gst_event_writable_structure (self->last_lost_event);
/* We are currently processing a picture, let's make sure the
* base depayloader doesn't drop this lost event */
gst_structure_remove_field (s, "might-have-been-fec");
}
return
GST_RTP_BASE_DEPAYLOAD_CLASS
(gst_rtp_vp9_depay_parent_class)->packet_lost (depay, event);
}