Add: TX_FLAG_EXACT_USER_PACING for video session (#1264)

if TX_FLAG_EXACT_USER_PACING is enabled, the lib does not align the
transmission time to the virtual receiver read schedule by adding
TR_offset. The first packet of the frame will be sent exactly at the
time specified by the user.

Additionally:
- Refactor tv_sync_pacing in st_tx_video_session.c
- Remove TX_FLAG_RTP_TIMESTAMP_FIRST_PKT
TX_FLAG_RTP_TIMESTAMP_FIRST_PKT did not changed behavior in any way.
    so its bit in mask was reused to TX_FLAG_EXACT_USER_PACING 
- Fix TX_FLAG_RTP_TIMESTAMP_EPOCH
This flag should force the lib to set RTP timestamp exactly to
N*frame_time.
It did not happen before, it just caused a few packets worth of time
difference.

---------

Signed-off-by: Kasiewicz, Marek <[email protected]>
Co-authored-by: Tomasz Szumski <[email protected]>

Author: Sakoram

config/tx_1v_user_pacing.json

@@ -0,0 +1,34 @@
+{
+    "interfaces": [
+        {
+            "name": "0000:af:01.0",
+            "ip": "192.168.30.10"
+        }
+    ],
+    "tx_sessions": [
+        {
+            "dip": [
+                "239.1.1.1"
+            ],
+            "interface": [
+                0
+            ],
+            "st20p": [
+                {
+                    "replicas": 1,
+                    "start_port": 20000,
+                    "payload_type": 112,
+                    "width": 1920,
+                    "height": 1080,
+                    "fps": "p59",
+                    "device": "AUTO",
+                    "input_format": "YUV422PLANAR10LE",
+                    "transport_format": "YUV_422_10bit",
+                    "st20p_url": "./yuv422p10le_1080p.yuv",
+                    "user_pacing": true
+                }
+            ],
+            "user_pacing_offset" : 20000000
+        }
+    ]
+}

include/st20_api.h

@@ -45,14 +45,16 @@ extern "C" {
 #define ST20_TX_FLAG_EXT_FRAME (MTL_BIT32(2))
 /**
  * Flag bit in flags of struct st20_tx_ops.
- * User control the frame pacing by pass a timestamp in st20_tx_frame_meta,
- * lib will wait until timestamp is reached for each frame.
+ * User control the frame transmission time by passing a timestamp in
+ * st20_tx_frame_meta.timestamp, lib will wait until timestamp is reached for each frame.
+ * The time of sending is aligned with virtual receiver read schedule.
  */
 #define ST20_TX_FLAG_USER_PACING (MTL_BIT32(3))
 /**
  * Flag bit in flags of struct st20_tx_ops.
- * If enabled, lib will assign the rtp timestamp to the value in
- * st20_tx_frame_meta(ST10_TIMESTAMP_FMT_MEDIA_CLK is used)
+ * If enabled, lib will assign the rtp timestamp to the value of
+ * t20_tx_frame_meta.timestamp (if needed the value will be converted to
+ * ST10_TIMESTAMP_FMT_MEDIA_CLK)
  */
 #define ST20_TX_FLAG_USER_TIMESTAMP (MTL_BIT32(4))
 /**
@@ -74,13 +76,15 @@ extern "C" {
 #define ST20_TX_FLAG_ENABLE_RTCP (MTL_BIT32(7))
 /**
  * Flag bit in flags of struct st20_tx_ops.
- * Set this flag to set rtp timestamp at the time of the first packet egresses from the
- * sender.
+ * It changes how ST20_TX_FLAG_USER_PACING works. if enabled, it does not align the
+ * transmission time to the virtual receiver read schedule. The first
+ * packet of the frame will be sent exactly at the time specified by the user.
  */
-#define ST20_TX_FLAG_RTP_TIMESTAMP_FIRST_PKT (MTL_BIT32(8))
+#define ST20_TX_FLAG_EXACT_USER_PACING (MTL_BIT32(8))
 /**
  * Flag bit in flags of struct st20_tx_ops.
- * Set this flag to set rtp timestamp at the time of the epoch.
+ * If enabled the RTP timestamp will be set exactly to epoch + N *
+ * frame_time, omitting TR_offset.
  */
 #define ST20_TX_FLAG_RTP_TIMESTAMP_EPOCH (MTL_BIT32(9))
 /**

include/st_pipeline_api.h

@@ -432,13 +432,15 @@ enum st20p_tx_flag {
    */
   ST20P_TX_FLAG_EXT_FRAME = (MTL_BIT32(2)),
   /**
-   * User control the frame pacing by pass a timestamp in st_frame,
-   * lib will wait until timestamp is reached for each frame.
+   * User control frame transmission time by pass a timestamp in st_frame.timestamp,
+   * lib will wait until timestamp is reached for each frame. The time of sending is
+   * aligned with virtual receiver read schedule.
    */
   ST20P_TX_FLAG_USER_PACING = (MTL_BIT32(3)),
   /**
-   * If enabled, lib will assign the rtp timestamp to the value in
-   * tx_frame_meta(ST10_TIMESTAMP_FMT_MEDIA_CLK is used)
+   * If enabled, lib will assign the rtp timestamp to the value of timestamp in
+   * st_frame.timestamp (if needed the value will be converted to
+   * ST10_TIMESTAMP_FMT_MEDIA_CLK)
    */
   ST20P_TX_FLAG_USER_TIMESTAMP = (MTL_BIT32(4)),
   /**
@@ -456,12 +458,14 @@ enum st20p_tx_flag {
    */
   ST20P_TX_FLAG_ENABLE_RTCP = (MTL_BIT32(7)),
   /**
-   * Set this flag to set rtp timestamp at the time of the first packet egresses from the
-   * sender.
+   * It changes how ST20_TX_FLAG_USER_PACING works. if enabled, it does not align the
+   * transmission time to the virtual receiver read schedule. The
+   * first packet of the frame will be sent exactly at the time specified by the user.
    */
-  ST20P_TX_FLAG_RTP_TIMESTAMP_FIRST_PKT = (MTL_BIT32(8)),
+  ST20P_TX_FLAG_EXACT_USER_PACING = (MTL_BIT32(8)),
   /**
-   * Set this flag to set rtp timestamp at the time of the epoch.
+   * If enabled the RTP timestamp will be set exactly to epoch + N *
+   * frame_time, omitting TR_offset.
    */
   ST20P_TX_FLAG_RTP_TIMESTAMP_EPOCH = (MTL_BIT32(9)),
   /**

lib/src/st2110/pipeline/st20_pipeline_tx.c

@@ -305,8 +305,8 @@ static int tx_st20p_create_transport(struct mtl_main_impl* impl, struct st20p_tx
     ops_tx.flags |= ST20_TX_FLAG_ENABLE_RTCP;
     ops_tx.rtcp = ops->rtcp;
   }
-  if (ops->flags & ST20P_TX_FLAG_RTP_TIMESTAMP_FIRST_PKT)
-    ops_tx.flags |= ST20_TX_FLAG_RTP_TIMESTAMP_FIRST_PKT;
+  if (ops->flags & ST20P_TX_FLAG_EXACT_USER_PACING)
+    ops_tx.flags |= ST20_TX_FLAG_EXACT_USER_PACING;
   if (ops->flags & ST20P_TX_FLAG_RTP_TIMESTAMP_EPOCH)
     ops_tx.flags |= ST20_TX_FLAG_RTP_TIMESTAMP_EPOCH;
   if (ops->flags & ST20P_TX_FLAG_DISABLE_BULK) ops_tx.flags |= ST20_TX_FLAG_DISABLE_BULK;

lib/src/st2110/st_fmt.c

@@ -907,14 +907,14 @@ bool st_frame_fmt_equal_transport(enum st_frame_fmt fmt, enum st20_fmt tfmt) {
 }
 
 uint32_t st10_tai_to_media_clk(uint64_t tai_ns, uint32_t sampling_rate) {
-  double ts = (double)tai_ns * sampling_rate / NS_PER_S;
+  long double ts = (long double)tai_ns * sampling_rate / NS_PER_S;
   uint64_t tmstamp64 = ts;
   uint32_t tmstamp32 = tmstamp64;
   return tmstamp32;
 }
 
 uint64_t st10_media_clk_to_ns(uint32_t media_ts, uint32_t sampling_rate) {
-  double ts = (double)media_ts * NS_PER_S / sampling_rate;
+  long double ts = (long double)media_ts * NS_PER_S / sampling_rate;
   return ts;
 }
 

lib/src/st2110/st_header.h

@@ -188,9 +188,8 @@ struct st_tx_video_pacing {
   uint64_t cur_epochs; /* epoch of current frame */
   /* timestamp for rtp header */
   uint32_t rtp_time_stamp;
-  uint64_t cur_epoch_time;
-  double tsc_time_cursor; /* in ns, tsc time cursor for packet pacing */
-  double ptp_time_cursor; /* in ns, ptp time cursor for packet pacing */
+  uint64_t tsc_time_cursor; /* in ns, tsc time cursor for packet pacing */
+  uint64_t ptp_time_cursor; /* in ns, ptp time cursor for packet pacing */
   /* ptp time may onward */
   uint32_t max_onward_epochs;
   uint64_t tsc_time_frame_start; /* start tsc time for frame start */