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/*
* GStreamer AVTP Plugin
* Copyright (C) 2019 Intel Corporation
*
* 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.
*/
/**
* SECTION:element-avtpcrfsync
* @see_also: avtpcrfcheck
*
* Adjust the Presentation Time from AVTPDUs to align with the reference clock
* provided by the CRF stream. For detailed information see chapter 10 in
* https://standards.ieee.org/standard/1722-2016.html. A helpful aid for
* visualizing CRF and it's advantages can be found at
* http://grouper.ieee.org/groups/1722/contributions/2014/1722a-rsilfvast-Diagrams%20for%20Common%20Timing%20Grid%20and%20Presentation%20Time%20(for%20review%20and%20discussion).pdf
* (Look at page 1).
*
* <refsect2>
* <title>Example pipeline</title>
* |[
* gst-launch-1.0 audiotestsrc ! audioconvert ! avtpaafpay ! avtpcrfsync ! avtpsink
* ]| This example pipeline will adjust the timestamps for rawaudio payload.
* Refer to the avtpcrfcheck example to validate the adjusted timestamp.
* </refsect2>
*/
#include <avtp.h>
#include <avtp_aaf.h>
#include <avtp_crf.h>
#include <avtp_cvf.h>
#include <glib.h>
#include <math.h>
#include "gstavtpcrfbase.h"
#include "gstavtpcrfsync.h"
#include "gstavtpcrfutil.h"
GST_DEBUG_CATEGORY_STATIC (avtpcrfsync_debug);
#define GST_CAT_DEFAULT (avtpcrfsync_debug)
#define gst_avtp_crf_sync_parent_class parent_class
G_DEFINE_TYPE (GstAvtpCrfSync, gst_avtp_crf_sync, GST_TYPE_AVTP_CRF_BASE);
GST_ELEMENT_REGISTER_DEFINE (avtpcrfsync, "avtpcrfsync", GST_RANK_NONE,
GST_TYPE_AVTP_CRF_SYNC);
static GstFlowReturn gst_avtp_crf_sync_transform_ip (GstBaseTransform * parent,
GstBuffer * buffer);
static void
gst_avtp_crf_sync_class_init (GstAvtpCrfSyncClass * klass)
{
GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
gst_element_class_set_static_metadata (element_class,
"Clock Reference Format (CRF) Synchronizer",
"Filter/Network/AVTP",
"Synchronize Presentation Time from AVTPDUs so they are phase-locked with clock provided by CRF stream",
"Vedang Patel <vedang.patel@intel.com>");
GST_BASE_TRANSFORM_CLASS (klass)->transform_ip =
GST_DEBUG_FUNCPTR (gst_avtp_crf_sync_transform_ip);
GST_DEBUG_CATEGORY_INIT (avtpcrfsync_debug, "avtpcrfsync", 0,
"CRF Synchronizer");
}
static void
gst_avtp_crf_sync_init (GstAvtpCrfSync * avtpcrfsync)
{
/* Nothing to do here. */
}
static void
set_avtp_tstamp (GstAvtpCrfSync * avtpcrfsync, struct avtp_stream_pdu *pdu,
GstClockTime tstamp)
{
int res;
guint32 type;
res =
avtp_pdu_get ((struct avtp_common_pdu *) pdu, AVTP_FIELD_SUBTYPE, &type);
g_assert (res == 0);
switch (type) {
case AVTP_SUBTYPE_AAF:
res = avtp_aaf_pdu_set (pdu, AVTP_AAF_FIELD_TIMESTAMP, tstamp);
g_assert (res == 0);
break;
case AVTP_SUBTYPE_CVF:
res = avtp_cvf_pdu_set (pdu, AVTP_CVF_FIELD_TIMESTAMP, tstamp);
g_assert (res == 0);
break;
default:
GST_ERROR_OBJECT (avtpcrfsync, "type 0x%x not supported.\n", type);
break;
}
}
static void
set_avtp_mr_bit (GstAvtpCrfSync * avtpcrfsync, struct avtp_stream_pdu *pdu,
guint64 mr)
{
int res;
guint32 type;
res =
avtp_pdu_get ((struct avtp_common_pdu *) pdu, AVTP_FIELD_SUBTYPE, &type);
g_assert (res == 0);
switch (type) {
case AVTP_SUBTYPE_AAF:
res = avtp_aaf_pdu_set (pdu, AVTP_AAF_FIELD_MR, mr);
g_assert (res == 0);
break;
case AVTP_SUBTYPE_CVF:
res = avtp_cvf_pdu_set (pdu, AVTP_CVF_FIELD_MR, mr);
g_assert (res == 0);
break;
default:
GST_ERROR_OBJECT (avtpcrfsync, "type 0x%x not supported.\n", type);
break;
}
}
static GstFlowReturn
gst_avtp_crf_sync_transform_ip (GstBaseTransform * parent, GstBuffer * buffer)
{
GstClockTime tstamp, h264_time = 0, adjusted_tstamp, adjusted_h264_time = 0;
GstAvtpCrfBase *avtpcrfbase = GST_AVTP_CRF_BASE (parent);
GstAvtpCrfSync *avtpcrfsync = GST_AVTP_CRF_SYNC (avtpcrfbase);
GstAvtpCrfThreadData *thread_data = &avtpcrfbase->thread_data;
GstClockTime current_ts = thread_data->current_ts;
gdouble avg_period = thread_data->average_period;
struct avtp_stream_pdu *pdu;
gboolean h264_packet;
GstMapInfo info;
gboolean res;
if (!avg_period || !current_ts)
return GST_FLOW_OK;
res = gst_buffer_map (buffer, &info, GST_MAP_READWRITE);
if (!res) {
GST_ELEMENT_ERROR (avtpcrfsync, RESOURCE, OPEN_WRITE,
("cannot access buffer"), (NULL));
return GST_FLOW_ERROR;
}
if (!buffer_size_valid (&info)) {
GST_DEBUG_OBJECT (avtpcrfsync, "Malformed AVTPDU, discarding it");
goto exit;
}
pdu = (struct avtp_stream_pdu *) info.data;
h264_packet = h264_tstamp_valid (pdu);
if (h264_packet) {
res = avtp_cvf_pdu_get (pdu, AVTP_CVF_FIELD_H264_TIMESTAMP, &h264_time);
g_assert (res == 0);
/*
* Extrapolate H264 tstamp to 64 bit and assume it's greater than CRF
* timestamp.
*/
h264_time |= current_ts & 0xFFFFFFFF00000000;
if (h264_time < current_ts)
h264_time += (1ULL << 32);
/*
* float typecasted to guint64 truncates the decimal part. So, round() it
* before casting.
*/
adjusted_h264_time =
(GstClockTime) roundl (current_ts + ceill (((gdouble) h264_time -
current_ts) / avg_period) * avg_period);
res =
avtp_cvf_pdu_set (pdu, AVTP_CVF_FIELD_H264_TIMESTAMP,
adjusted_h264_time);
g_assert (res == 0);
GST_LOG_OBJECT (avtpcrfsync,
"Adjust H264 timestamp in CVF packet. tstamp: %" G_GUINT64_FORMAT
" adjusted_tstamp: %" G_GUINT64_FORMAT,
h264_time & 0xFFFFFFFF, adjusted_h264_time & 0xFFFFFFFF);
}
tstamp = get_avtp_tstamp (avtpcrfbase, pdu);
if (tstamp == GST_CLOCK_TIME_NONE)
goto exit;
/*
* Extrapolate the 32-bit AVTP Timestamp to 64-bit and assume it's greater
* than the 64-bit CRF timestamp.
*/
tstamp |= current_ts & 0xFFFFFFFF00000000;
if (tstamp < current_ts)
tstamp += (1ULL << 32);
/*
* float typecasted to guint64 truncates the decimal part. So, round() it
* before casting.
*/
adjusted_tstamp =
(GstClockTime) roundl (current_ts + ceill ((tstamp -
current_ts) / avg_period) * avg_period);
set_avtp_tstamp (avtpcrfsync, pdu, adjusted_tstamp);
set_avtp_mr_bit (avtpcrfsync, pdu, thread_data->mr);
GST_LOG_OBJECT (avtpcrfsync,
"Adjust AVTP timestamp. tstamp: %" G_GUINT64_FORMAT
" Adjusted tstamp: %" G_GUINT64_FORMAT,
tstamp & 0xFFFFFFFF, adjusted_tstamp & 0xFFFFFFFF);
/*
* Since we adjusted the AVTP/H264 presentation times in the AVTPDU, we also
* need to adjust buffer times by the same amount so that the buffer is
* transmitted at the right time.
*/
if (h264_packet) {
if (GST_BUFFER_DTS (buffer) != GST_CLOCK_TIME_NONE)
GST_BUFFER_DTS (buffer) += adjusted_tstamp - tstamp;
GST_BUFFER_PTS (buffer) += adjusted_h264_time - h264_time;
} else {
GST_BUFFER_PTS (buffer) += adjusted_tstamp - tstamp;
}
exit:
gst_buffer_unmap (buffer, &info);
return GST_FLOW_OK;
}
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