From 755472124fb6a12d8e32045b3577cba0f9d786fe Mon Sep 17 00:00:00 2001
From: Stefano Sabatini <stefasab@gmail.com>
Date: Tue, 12 Apr 2016 18:16:21 +0200
Subject: [PATCH] lavf/mpegtsenc: write metadata descriptor for timed ID3
 packets

This is required since some programs are not able to correctly recognize
the metadata. See H.222, 2.6.58 Metadata pointer descriptor.

putstr8() is modified in order to allow to skip writing the string
length.
---
 libavformat/mpegtsenc.c | 24 ++++++++++++++----------
 1 file changed, 14 insertions(+), 10 deletions(-)

diff --git a/libavformat/mpegtsenc.c b/libavformat/mpegtsenc.c
index ca038a625f..cdd7e37a1f 100644
--- a/libavformat/mpegtsenc.c
+++ b/libavformat/mpegtsenc.c
@@ -265,7 +265,7 @@ static void mpegts_write_pat(AVFormatContext *s)
 }
 
 /* NOTE: !str is accepted for an empty string */
-static void putstr8(uint8_t **q_ptr, const char *str)
+static void putstr8(uint8_t **q_ptr, const char *str, int write_len)
 {
     uint8_t *q;
     int len;
@@ -275,7 +275,8 @@ static void putstr8(uint8_t **q_ptr, const char *str)
         len = 0;
     else
         len = strlen(str);
-    *q++ = len;
+    if (write_len)
+        *q++ = len;
     memcpy(q, str, len);
     q     += len;
     *q_ptr = q;
@@ -637,12 +638,15 @@ static int mpegts_write_pmt(AVFormatContext *s, MpegTSService *service)
                 *q++ = 'V';
                 *q++ = 'A';
             } else if (st->codecpar->codec_id == AV_CODEC_ID_TIMED_ID3) {
-                *q++ = 0x5; /* MPEG-2 registration descriptor */
-                *q++ = 4;
-                *q++ = 'I';
-                *q++ = 'D';
-                *q++ = '3';
-                *q++ = ' ';
+                const char *tag = "ID3 ";
+                *q++ = 0x26; /* metadata descriptor */
+                *q++ = 13;
+                put16(&q, 0xffff);    /* metadata application format */
+                putstr8(&q, tag, 0);
+                *q++ = 0xff;        /* metadata format */
+                putstr8(&q, tag, 0);
+                *q++ = 0;            /* metadata service ID */
+                *q++ = 0xF;          /* metadata_locator_record_flag|MPEG_carriage_flags|reserved */
             }
             break;
         }
@@ -687,8 +691,8 @@ static void mpegts_write_sdt(AVFormatContext *s)
         desc_len_ptr = q;
         q++;
         *q++         = ts->service_type;
-        putstr8(&q, service->provider_name);
-        putstr8(&q, service->name);
+        putstr8(&q, service->provider_name, 1);
+        putstr8(&q, service->name, 1);
         desc_len_ptr[0] = q - desc_len_ptr - 1;
 
         /* fill descriptor length */