Commit e4c06deb authored by Olivier Crête's avatar Olivier Crête 👻 Committed by Wim Taymans
Browse files

rtpbuffer: Add function to parse RFC 5285 header extensions

RFC 5285 describes a generic method to add multiple header extensions to RTP packets.
These functions parse these headers and return them, both for the one-byte header and the
two bytes headers.
parent 7fe3657d
......@@ -1357,6 +1357,8 @@ gst_rtp_buffer_list_set_ssrc
gst_rtp_buffer_list_get_timestamp
gst_rtp_buffer_list_set_timestamp
gst_rtp_buffer_get_extension_onebyte_header
gst_rtp_buffer_get_extension_twobytes_header
</SECTION>
# rtsp
......
......@@ -1386,3 +1386,159 @@ gst_rtp_buffer_ext_timestamp (guint64 * exttimestamp, guint32 timestamp)
return result;
}
/**
* gst_rtp_buffer_get_extension_onebyte_header:
* @buffer: the buffer
* @id: The ID of the header extension to be read (between 1 and 14).
* @nth: Read the nth extension packet with the requested ID
* @data: location for data
* @size: the size of the data in bytes
*
* Parses RFC 5285 style header extensions with a one byte header. It will
* return the nth extension with the requested id.
*
* Returns: TRUE if @buffer had the requested header extension
*
* Since: 0.10.31
*/
gboolean
gst_rtp_buffer_get_extension_onebyte_header (GstBuffer * buffer, guint8 id,
guint nth, gpointer * data, guint * size)
{
guint16 bits;
guint8 *pdata;
guint wordlen;
gulong offset = 0;
guint count = 0;
g_return_val_if_fail (id > 0 && id < 15, FALSE);
if (!gst_rtp_buffer_get_extension_data (buffer, &bits, (gpointer) & pdata,
&wordlen))
return FALSE;
if (bits != 0xBEDE)
return FALSE;
for (;;) {
guint8 read_id, read_len;
if (offset + 1 >= wordlen * 4)
break;
read_id = GST_READ_UINT8 (pdata + offset) >> 4;
read_len = (GST_READ_UINT8 (pdata + offset) & 0x0F) + 1;
offset += 1;
/* ID 0 means its padding, skip */
if (read_id == 0)
continue;
/* ID 15 is special and means we should stop parsing */
if (read_id == 15)
break;
/* Ignore extension headers where the size does not fit */
if (offset + read_len > wordlen * 4)
break;
/* If we have the right one */
if (id == read_id) {
if (nth == count) {
if (data)
*data = pdata + offset;
if (size)
*size = read_len;
return TRUE;
}
count++;
}
offset += read_len;
if (offset >= wordlen * 4)
break;
}
return FALSE;
}
/**
* gst_rtp_buffer_get_extension_twobytes_header:
* @buffer: the buffer
* @appbits: Application specific bits
* @id: The ID of the header extension to be read (between 1 and 14).
* @nth: Read the nth extension packet with the requested ID
* @data: location for data
* @size: the size of the data in bytes
*
* Parses RFC 5285 style header extensions with a two bytes header. It will
* return the nth extension with the requested id.
*
* Returns: TRUE if @buffer had the requested header extension
*
* Since: 0.10.31
*/
gboolean
gst_rtp_buffer_get_extension_twobytes_header (GstBuffer * buffer,
guint8 * appbits, guint8 id, guint nth, gpointer * data, guint * size)
{
guint16 bits;
guint8 *pdata;
guint wordlen;
guint bytelen;
gulong offset = 0;
guint count = 0;
if (!gst_rtp_buffer_get_extension_data (buffer, &bits, (gpointer) & pdata,
&wordlen))
return FALSE;
if (bits >> 4 != 0x100)
return FALSE;
bytelen = wordlen * 4;
for (;;) {
guint8 read_id, read_len;
if (offset + 2 >= bytelen)
break;
read_id = GST_READ_UINT8 (pdata + offset);
offset += 1;
if (read_id == 0)
continue;
read_len = GST_READ_UINT8 (pdata + offset);
offset += 1;
/* Ignore extension headers where the size does not fit */
if (offset + read_len > bytelen)
break;
/* If we have the right one, return it */
if (id == read_id) {
if (nth == count) {
if (data)
*data = pdata + offset;
if (size)
*size = read_len;
if (appbits)
*appbits = bits;
return TRUE;
}
count++;
}
offset += read_len;
}
return FALSE;
}
......@@ -110,6 +110,20 @@ guint32 gst_rtp_buffer_default_clock_rate (guint8 payload_type);
gint gst_rtp_buffer_compare_seqnum (guint16 seqnum1, guint16 seqnum2);
guint64 gst_rtp_buffer_ext_timestamp (guint64 *exttimestamp, guint32 timestamp);
gboolean gst_rtp_buffer_get_extension_onebyte_header (GstBuffer * buffer,
guint8 id,
guint nth,
gpointer * data,
guint * size);
gboolean gst_rtp_buffer_get_extension_twobytes_header (GstBuffer * buffer,
guint8 * appbits,
guint8 id,
guint nth,
gpointer * data,
guint * size);
G_END_DECLS
#endif /* __GST_RTPBUFFER_H__ */
......
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