Docs: add the first mention of new arguemnts

Author: DawidWesierski4

ecosystem/gstreamer_plugin/README.md

@@ -395,14 +395,15 @@ The `mtl_st40p_tx` plugin supports all pad capabilities (the data is not checked
 - **Capabilities**: Any (GST_STATIC_CAPS_ANY)
 
 **Arguments**
-| Property Name      | Type     | Description                                                        | Range         | Default Value |
-|--------------------|----------|--------------------------------------------------------------------|---------------|---------------|
-| tx-framebuff-cnt   | uint     | Number of framebuffers to be used for transmission.                | 0 to G_MAXUINT| 3             |
-| tx-fps             | uint     | Framerate of the video to which the ancillary data is synchronized.| [Supported video fps fractions](#231-supported-video-fps-fractions) | 25/1 |
-| tx-did             | uint     | Data ID for the ancillary data.                                    | 0 to 255      | 0             |
-| tx-sdid            | uint     | Secondary Data ID for the ancillary data.                          | 0 to 255      | 0             |
-| use-pts-for-pacing | gboolean | [User controlled timestamping offset](#233-pts-controlled-pacing)  | 0 to G_MAXUINT | 0            |
-| pts-pacing-offset  | uint     | [User controlled timestamping offset](#233-pts-controlled-pacing)  | 0 to G_MAXUINT | 0            |
+| Property Name         | Type     | Description                                                        | Range          | Default Value |
+|-----------------------|----------|--------------------------------------------------------------------|----------------|---------------|
+| tx-framebuff-cnt      | uint     | Number of framebuffers to be used for transmission.                | 0 to G_MAXUINT | 3             |
+| tx-fps                | uint     | Framerate of the video to which the ancillary data is synchronized.| [Supported vid eo fps fractions](#231-supported-video-fps-fractions) | 25/1 |
+| tx-did                | uint     | Data ID for the ancillary data.                                    | 0 to 255       | 0             |
+| tx-sdid               | uint     | Secondary Data ID for the ancillary data.                          | 0 to 255       | 0             |
+| use-pts-for-pacing    | gboolean | [User controlled timestamping offset](#233-pts-controlled-pacing)  | 0 to G_MAXUINT | 0             |
+| pts-pacing-offset     | uint     | [User controlled timestamping offset](#233-pts-controlled-pacing)  | 0 to G_MAXUINT | 0             |
+| max-combined-udw-size | uint     | Maximum combined size of all user data words to send in one buffer | 0 to G_MAXUINT | 20 * 255      |
 
 #### 5.1.2. Example GStreamer Pipeline for Transmission
 

ecosystem/gstreamer_plugin/gst_mtl_st40p_tx.c

@@ -657,7 +657,7 @@ static GstFlowReturn st40p_tx_parse_8331_gstbuffer(Gst_Mtl_St40p_Tx* sink,
 
     /* Get the ANC 8331 header and move the goalpost variables */
     payload_cursor = map_info.data + (buffer_size - *bytes_left_to_process);
-    memcpy(&rfc8331_meta.hdr, payload_cursor, sizeof(struct gst_st40_rfc8331_hdr1_le));
+    memcpy(&rfc8331_meta.hdr, payload_cursor, sizeof(struct gst_st40_rfc8331_payload_first_word));
 
     ST40P_TX_SHIFT_BUFFER(payload_cursor, *bytes_left_to_process, RFC_8331_WORD_BYTE_SIZE);
     /*TODO add support for parity bit checking we are ignoring the parity bits  */

ecosystem/gstreamer_plugin/gst_mtl_st40p_tx.h

@@ -86,7 +86,8 @@ struct _Gst_Mtl_St40p_Tx {
 };
 
 
-struct gst_st40_rfc8331_hdr1_le {
+#ifdef MTL_LITTLE_ENDIAN
+struct gst_st40_rfc8331_payload_first_word {
   union {
     struct {
       /** the ANC data uses luma (Y) data channel */
@@ -103,10 +104,29 @@ struct gst_st40_rfc8331_hdr1_le {
     uint32_t handle;
   };
 };
+#else
+struct gst_st40_rfc8331_payload_first_word {
+  union {
+    struct {
+      /** whether the data stream number of a multi-stream data mapping */
+      uint32_t s : 1;
+      /** the source data stream number of the ANC data packet */
+      uint32_t stream_num : 7;
+      /** the location of the ANC data packet in the SDI raster */
+      uint32_t horizontal_offset : 12;
+      /** line number corresponds to the location (vertical) of the ANC data packet */
+      uint32_t line_number : 11;
+      /** the ANC data uses luma (Y) data channel */
+      uint32_t c : 1;
+    } header;
+    uint32_t handle;
+  };
+};
+#endif
 
 
 struct gst_st40_rfc8331_meta {
-  struct gst_st40_rfc8331_hdr1_le hdr;
+  struct gst_st40_rfc8331_payload_first_word hdr;
   /** Data Count */
   guint16 data_count;
   /** Secondary Data Identification Word */