rtmp: Add a function for writing AMF strings based on two substrings

This avoids having to concatenate them into one buffer before writing
them as AMF.

Signed-off-by: Martin Storsjö <martin@martin.st>

2 files changed, 22 insertions, 0 deletions

diff --git a/libavformat/rtmppkt.c b/libavformat/rtmppkt.c
index f69ce82c66..aed188dcc7 100644
--- a/libavformat/rtmppkt.c
+++ b/libavformat/rtmppkt.c
@@ -47,6 +47,19 @@ void ff_amf_write_string(uint8_t **dst, const char *str)
     bytestream_put_buffer(dst, str, strlen(str));
 }
 
+void ff_amf_write_string2(uint8_t **dst, const char *str1, const char *str2)
+{
+    int len1 = 0, len2 = 0;
+    if (str1)
+        len1 = strlen(str1);
+    if (str2)
+        len2 = strlen(str2);
+    bytestream_put_byte(dst, AMF_DATA_TYPE_STRING);
+    bytestream_put_be16(dst, len1 + len2);
+    bytestream_put_buffer(dst, str1, len1);
+    bytestream_put_buffer(dst, str2, len2);
+}
+
 void ff_amf_write_null(uint8_t **dst)
 {
     bytestream_put_byte(dst, AMF_DATA_TYPE_NULL);
diff --git a/libavformat/rtmppkt.h b/libavformat/rtmppkt.h
index a153ca6253..276c5608c0 100644
--- a/libavformat/rtmppkt.h
+++ b/libavformat/rtmppkt.h
@@ -204,6 +204,15 @@ void ff_amf_write_number(uint8_t **dst, double num);
 void ff_amf_write_string(uint8_t **dst, const char *str);
 
 /**
+ * Write a string consisting of two parts in AMF format to a buffer.
+ *
+ * @param dst pointer to the input buffer (will be modified)
+ * @param str1 first string to write, may be null
+ * @param str2 second string to write, may be null
+ */
+void ff_amf_write_string2(uint8_t **dst, const char *str1, const char *str2);
+
+/**
  * Write AMF NULL value to buffer.
  *
  * @param dst pointer to the input buffer (will be modified)