From 4e9cb5d8ebdb615ff1c17633499e4ef8f64a721e Mon Sep 17 00:00:00 2001
From: "Jan Alexander Steffens (heftig)" <jan.steffens@ltnglobal.com>
Date: Mon, 16 Oct 2023 23:52:48 +0200
Subject: [PATCH] tsmux: Move out parameters of tsmux_write_ts_header

Move them to the end of the parameter list and also allow passing NULLs
to ignore the payload information, but assert that the payload length is
zero in this case.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/5516>
---
 .../gst/mpegtsmux/tsmux/tsmux.c               | 37 ++++++++++---------
 1 file changed, 20 insertions(+), 17 deletions(-)

diff --git a/subprojects/gst-plugins-bad/gst/mpegtsmux/tsmux/tsmux.c b/subprojects/gst-plugins-bad/gst/mpegtsmux/tsmux/tsmux.c
index b55b763f38..ff4f0d92a8 100644
--- a/subprojects/gst-plugins-bad/gst/mpegtsmux/tsmux/tsmux.c
+++ b/subprojects/gst-plugins-bad/gst/mpegtsmux/tsmux/tsmux.c
@@ -106,8 +106,8 @@ static gint64 get_current_pcr (TsMux * mux, gint64 cur_ts);
 static gint64 write_new_pcr (TsMux * mux, TsMuxStream * stream, gint64 cur_pcr,
     gint64 next_pcr);
 static gboolean tsmux_write_ts_header (TsMux * mux, guint8 * buf,
-    TsMuxPacketInfo * pi, guint * payload_len_out, guint * payload_offset_out,
-    guint stream_avail);
+    TsMuxPacketInfo * pi, guint stream_avail, guint * payload_len_out,
+    guint * payload_offset_out);
 
 static void
 tsmux_section_free (TsMuxSection * section)
@@ -865,15 +865,13 @@ tsmux_packet_out (TsMux * mux, GstBuffer * buf, gint64 pcr)
         if (new_pcr != -1) {
           GstBuffer *buf = NULL;
           GstMapInfo map;
-          guint payload_len, payload_offs;
 
           if (!tsmux_get_buffer (mux, &buf)) {
             goto error;
           }
 
           gst_buffer_map (buf, &map, GST_MAP_WRITE);
-          tsmux_write_ts_header (mux, map.data, &stream->pi, &payload_len,
-              &payload_offs, 0);
+          tsmux_write_ts_header (mux, map.data, &stream->pi, 0, NULL, NULL);
           gst_buffer_unmap (buf, &map);
 
           stream->pi.flags &= TSMUX_PACKET_FLAG_PES_FULL_HEADER;
@@ -1049,7 +1047,7 @@ tsmux_write_adaptation_field (guint8 * buf,
 
 static gboolean
 tsmux_write_ts_header (TsMux * mux, guint8 * buf, TsMuxPacketInfo * pi,
-    guint * payload_len_out, guint * payload_offset_out, guint stream_avail)
+    guint stream_avail, guint * payload_len_out, guint * payload_offset_out)
 {
   guint8 *tmp;
   guint8 adaptation_flag = 0;
@@ -1107,8 +1105,15 @@ tsmux_write_ts_header (TsMux * mux, guint8 * buf, TsMuxPacketInfo * pi,
 
   /* The amount of packet data we wrote is the remaining space after
    * the adaptation field */
-  *payload_len_out = payload_len = TSMUX_PAYLOAD_LENGTH - adapt_len;
-  *payload_offset_out = TSMUX_HEADER_LENGTH + adapt_len;
+  payload_len = TSMUX_PAYLOAD_LENGTH - adapt_len;
+
+  if (payload_len_out)
+    *payload_len_out = payload_len;
+  else
+    g_assert (payload_len == 0);
+
+  if (payload_offset_out)
+    *payload_offset_out = TSMUX_HEADER_LENGTH + adapt_len;
 
   /* Now if we are going to write out some payload, flag that fact */
   if (payload_len > 0 && stream_avail > 0) {
@@ -1188,8 +1193,8 @@ tsmux_section_write_packet (gpointer unused_arg,
       /* Wee need room for a pointer byte */
       section->pi.stream_avail++;
 
-      if (!tsmux_write_ts_header (mux, packet, &section->pi, &len, &offset,
-              section->pi.stream_avail))
+      if (!tsmux_write_ts_header (mux, packet, &section->pi,
+            section->pi.stream_avail, &len, &offset))
         goto fail;
 
       /* Write the pointer byte */
@@ -1197,8 +1202,8 @@ tsmux_section_write_packet (gpointer unused_arg,
       payload_len = len - 1;
 
     } else {
-      if (!tsmux_write_ts_header (mux, packet, &section->pi, &len, &offset,
-              section->pi.stream_avail))
+      if (!tsmux_write_ts_header (mux, packet, &section->pi,
+            section->pi.stream_avail, &len, &offset))
         goto fail;
       payload_len = len;
     }
@@ -1532,7 +1537,6 @@ pad_stream (TsMux * mux, TsMuxStream * stream, gint64 cur_ts)
 
     if (bitrate <= mux->bitrate) {
       gint64 new_pcr;
-      guint payload_len, payload_offs;
 
       if (!tsmux_get_buffer (mux, &buf)) {
         ret = FALSE;
@@ -1551,8 +1555,7 @@ pad_stream (TsMux * mux, TsMuxStream * stream, gint64 cur_ts)
           get_next_pcr (mux, cur_ts));
       if (new_pcr != -1) {
         GST_LOG ("Writing PCR-only packet on PID 0x%04x", stream->pi.pid);
-        tsmux_write_ts_header (mux, map.data, &stream->pi, &payload_len,
-            &payload_offs, 0);
+        tsmux_write_ts_header (mux, map.data, &stream->pi, 0, NULL, NULL);
       } else {
         GST_LOG ("Writing null stuffing packet");
         if (!rewrite_si (mux, cur_ts)) {
@@ -1639,8 +1642,8 @@ tsmux_write_stream_packet (TsMux * mux, TsMuxStream * stream)
 
   gst_buffer_map (buf, &map, GST_MAP_WRITE);
 
-  if (!tsmux_write_ts_header (mux, map.data, pi, &payload_len, &payload_offs,
-          pi->stream_avail))
+  if (!tsmux_write_ts_header (mux, map.data, pi, pi->stream_avail, &payload_len,
+          &payload_offs))
     goto fail;