Add PTP hardware timing support to MTL and FFmpeg TX paths

include/app_context.h

@@ -61,6 +61,13 @@ struct dvledtx_context {
   bool force_dhcp;
   int test_time_s;
 
+  /* PTP hardware timing (built-in MTL PTP client, FFmpeg mtl_st20p muxer path).
+   * See MTL_FLAG_PTP_* in mtl_api.h. Only used when ENABLE_MTL_TX is NOT set
+   * (the FFmpeg avdevice TX path); passed through as AVOptions in ffmpeg_tx.c. */
+  bool ptp_enable;   /* enable built-in PTP client + PTP-paced TX */
+  bool ptp_pi;        /* use PI controller for built-in PTP (PF only) */
+  bool ptp_unicast;   /* use unicast address for PTP_DELAY_REQ message */
+
   /* Per-session network + crop config — dynamically allocated, st20p_sessions elements */
   struct tx_session_net* session_net;
 

include/util/config_reader.h

@@ -42,6 +42,12 @@ struct dvledtx_config {
   /* optional log file path (empty = console only) */
   char log_file[256];
 
+  /* PTP hardware timing (built-in MTL PTP client) — hardcoded in config_reader.c,
+   * not configurable via JSON. */
+  int ptp_enable;
+  int ptp_pi;
+  int ptp_unicast;
+
   /* tx_sessions array — dynamically allocated */
   int session_count;
   int session_cap;                             /* allocated capacity */

src/ffmpeg/ffmpeg_tx.c

@@ -99,6 +99,18 @@ int open_ffmpeg_tx(struct st20p_tx_ctx* ctx) {
   ret = av_opt_set_int(ctx->out_fmt_ctx->priv_data, "payload_type", (int64_t)payload_type,  0);
   if (ret < 0) LOG_WARN("ST20P TX(%d): av_opt_set_int payload_type failed (ret=%d)", ctx->idx, ret);
 
+  /* PTP hardware timing (built-in MTL PTP client). Only takes effect on the
+   * session that actually calls mtl_init() (mtl_dev_get()'s singleton shared
+   * handle) — harmless to set on every session. */
+  if (ctx->app->ptp_enable) {
+    ret = av_opt_set_int(ctx->out_fmt_ctx->priv_data, "ptp_enable", 1, 0);
+    if (ret < 0) LOG_WARN("ST20P TX(%d): av_opt_set_int ptp_enable failed (ret=%d)", ctx->idx, ret);
+    ret = av_opt_set_int(ctx->out_fmt_ctx->priv_data, "ptp_pi", ctx->app->ptp_pi ? 1 : 0, 0);
+    if (ret < 0) LOG_WARN("ST20P TX(%d): av_opt_set_int ptp_pi failed (ret=%d)", ctx->idx, ret);
+    ret = av_opt_set_int(ctx->out_fmt_ctx->priv_data, "ptp_unicast", ctx->app->ptp_unicast ? 1 : 0, 0);
+    if (ret < 0) LOG_WARN("ST20P TX(%d): av_opt_set_int ptp_unicast failed (ret=%d)", ctx->idx, ret);
+  }
+
   /* Multi-NIC: The FFmpeg mtl_st20p plugin's mtl_dev_get() uses a singleton
    * shared MTL handle — the FIRST avformat_write_header() call creates the
    * MTL instance via mtl_init(), which initialises DPDK EAL.  EAL cannot be

src/mtl/mtl_tx.c

@@ -30,6 +30,7 @@
 #include "app_context.h"
 #include "core/session_manager.h"
 #include "util/logger.h"
+#include <inttypes.h>
 #include <string.h>
 #include <stdlib.h>
 #include <unistd.h>
@@ -198,13 +199,31 @@ void mtl_copy_crop_to_frame(struct st_frame* dst, const AVFrame* src,
  *
  * mtl_tx_uninit() — release the MTL library instance.
  */
+/* PTP hardware timing (built-in MTL PTP client, direct MTL TX path).
+ * See MTL_FLAG_PTP_* in mtl_api.h. Mirrors the AVOption-driven callback
+ * wired for the FFmpeg muxer path in the external ffmpeg_plugin repo. */
+static void mtl_tx_ptp_sync_notify_cb(void* priv, struct mtl_ptp_sync_notify_meta* meta) {
+  (void)priv;
+  LOG_INFO("PTP sync: master_utc_offset=%d delta=%" PRId64 "ns",
+            meta->master_utc_offset, meta->delta);
+}
+
 int mtl_tx_init(session_manager_t* manager, struct dvledtx_context* app) {
   struct mtl_init_params mtl_params;
   memset(&mtl_params, 0, sizeof(mtl_params));
 
   mtl_params.flags     = MTL_FLAG_BIND_NUMA | MTL_FLAG_DEV_AUTO_START_STOP;
   mtl_params.num_ports = app->nic_count;
 
+  if (app->ptp_enable) {
+    mtl_params.flags |= MTL_FLAG_PTP_ENABLE;
+    mtl_params.pacing = ST21_TX_PACING_WAY_PTP;
+    if (app->ptp_pi) mtl_params.flags |= MTL_FLAG_PTP_PI;
+    if (app->ptp_unicast) mtl_params.flags |= MTL_FLAG_PTP_UNICAST_ADDR;
+    mtl_params.ptp_sync_notify = mtl_tx_ptp_sync_notify_cb;
+    LOG_INFO("MTL init: PTP enabled (pi=%d unicast=%d)", app->ptp_pi, app->ptp_unicast);
+  }
+
   /* Count sessions assigned to each NIC for queue allocation */
   int* sessions_per_nic = calloc((size_t)app->nic_count, sizeof(int));
   if (sessions_per_nic == NULL) {

src/util/config_reader.c

@@ -328,6 +328,11 @@ int parse_tx_config(const char* config_file, struct dvledtx_config* config) {
     /* --- optional top-level log_file --- */
     extract_json_string(json, buf_end, "log_file", config->log_file, sizeof(config->log_file));
 
+    /* PTP hardware timing (built-in MTL PTP client) — hardcoded, not configurable via JSON. */
+    config->ptp_enable  = true;
+    config->ptp_pi      = true;
+    config->ptp_unicast = false;
+
     /* --- tx_sessions array --- */
     const char* sessions_arr = find_array(json, buf_end, "tx_sessions");
     if (sessions_arr == NULL) {
@@ -798,6 +803,14 @@ int load_and_apply_config(struct dvledtx_context* app, const char* config_file)
         app->log_file[sizeof(app->log_file) - 1] = '\0';
     }
 
+    /* PTP hardware timing (built-in MTL PTP client) */
+    app->ptp_enable  = config.ptp_enable;
+    app->ptp_pi      = config.ptp_pi;
+    app->ptp_unicast = config.ptp_unicast;
+    if (app->ptp_enable)
+        LOG_INFO("PTP enabled: pi_controller=%d unicast_delay_req=%d",
+                 app->ptp_pi, app->ptp_unicast);
+
     LOG_INFO("Config loaded: %s (%d NIC(s), %d session(s))",
              config_file, config.nic_count, config.session_count);
     for (int ni = 0; ni < config.nic_count; ni++)