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/* GStreamer RTP ASF depayloader
* Copyright (C) 2006 Tim-Philipp Müller <tim centricular net>
* 2009 Wim Taymans <wim.taymans@gmail.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include "gstrtpasfdepay.h"
#include <gst/rtp/gstrtpbuffer.h>
#include <string.h>
#include <stdlib.h>
GST_DEBUG_CATEGORY_STATIC (rtpasfdepayload_debug);
#define GST_CAT_DEFAULT rtpasfdepayload_debug
static GstStaticPadTemplate src_factory = GST_STATIC_PAD_TEMPLATE ("src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("video/x-ms-asf")
);
/* Other parameters: config, maxps */
#define SINK_CAPS \
"application/x-rtp, " \
"media = (string) { \"application\", \"video\", \"audio\" }, " \
"payload = (int) " GST_RTP_PAYLOAD_DYNAMIC_STRING ", " \
"clock-rate = (int) [1, MAX ], " \
"encoding-name = (string) \"X-ASF-PF\""
static GstStaticPadTemplate sink_factory = GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS (SINK_CAPS)
);
#define gst_rtp_asf_depay_parent_class parent_class
G_DEFINE_TYPE (GstRtpAsfDepay, gst_rtp_asf_depay, GST_TYPE_RTP_BASE_DEPAYLOAD);
static void gst_rtp_asf_depay_finalize (GObject * object);
static GstStateChangeReturn gst_rtp_asf_depay_change_state (GstElement *
element, GstStateChange transition);
static gboolean gst_rtp_asf_depay_setcaps (GstRTPBaseDepayload * depay,
GstCaps * caps);
static GstBuffer *gst_rtp_asf_depay_process (GstRTPBaseDepayload * basedepay,
GstBuffer * buf);
static void
gst_rtp_asf_depay_class_init (GstRtpAsfDepayClass * klass)
{
GObjectClass *gobject_class;
GstElementClass *gstelement_class;
GstRTPBaseDepayloadClass *gstrtpbasedepayload_class;
gobject_class = (GObjectClass *) klass;
gstelement_class = (GstElementClass *) klass;
gstrtpbasedepayload_class = (GstRTPBaseDepayloadClass *) klass;
gst_element_class_add_static_pad_template (gstelement_class, &src_factory);
gst_element_class_add_static_pad_template (gstelement_class, &sink_factory);
gst_element_class_set_static_metadata (gstelement_class,
"RTP ASF packet depayloader", "Codec/Depayloader/Network",
"Extracts ASF streams from RTP",
"Tim-Philipp Müller <tim centricular net>, "
"Wim Taymans <wim.taymans@gmail.com>");
gobject_class->finalize = gst_rtp_asf_depay_finalize;
gstelement_class->change_state =
GST_DEBUG_FUNCPTR (gst_rtp_asf_depay_change_state);
gstrtpbasedepayload_class->set_caps =
GST_DEBUG_FUNCPTR (gst_rtp_asf_depay_setcaps);
gstrtpbasedepayload_class->process =
GST_DEBUG_FUNCPTR (gst_rtp_asf_depay_process);
GST_DEBUG_CATEGORY_INIT (rtpasfdepayload_debug, "rtpasfdepayload", 0,
"RTP asf depayloader element");
}
static void
gst_rtp_asf_depay_init (GstRtpAsfDepay * depay)
{
depay->adapter = gst_adapter_new ();
}
static void
gst_rtp_asf_depay_finalize (GObject * object)
{
GstRtpAsfDepay *depay;
depay = GST_RTP_ASF_DEPAY (object);
g_object_unref (depay->adapter);
G_OBJECT_CLASS (parent_class)->finalize (object);
}
static const guint8 asf_marker[16] = { 0x30, 0x26, 0xb2, 0x75, 0x8e, 0x66,
0xcf, 0x11, 0xa6, 0xd9, 0x00, 0xaa, 0x00, 0x62, 0xce, 0x6c
};
static gboolean
gst_rtp_asf_depay_setcaps (GstRTPBaseDepayload * depayload, GstCaps * caps)
{
GstRtpAsfDepay *depay;
GstStructure *s;
const gchar *config_str, *ps_string;
GstBuffer *buf;
GstCaps *src_caps;
guint8 *headers;
gsize headers_len;
gint clock_rate;
depay = GST_RTP_ASF_DEPAY (depayload);
s = gst_caps_get_structure (caps, 0);
if (!gst_structure_get_int (s, "clock-rate", &clock_rate) || clock_rate < 0)
clock_rate = 1000;
depayload->clock_rate = clock_rate;
/* config contains the asf headers in base64 coding */
config_str = gst_structure_get_string (s, "config");
if (config_str == NULL || *config_str == '\0')
goto no_config;
ps_string = gst_structure_get_string (s, "maxps");
if (ps_string == NULL || *ps_string == '\0')
goto no_packetsize;
if (depay->packet_size) {
/* header sent again following seek;
* discard to avoid confusing upstream */
if (depay->packet_size == atoi (ps_string)) {
goto duplicate_header;
} else {
/* since we should fiddle with downstream state to handle this */
goto refuse_renegotiation;
}
} else
depay->packet_size = atoi (ps_string);
if (depay->packet_size <= 16)
goto invalid_packetsize;
headers = (guint8 *) g_base64_decode (config_str, &headers_len);
if (headers == NULL || headers_len < 16
|| memcmp (headers, asf_marker, 16) != 0)
goto invalid_headers;
src_caps = gst_caps_new_empty_simple ("video/x-ms-asf");
gst_pad_set_caps (depayload->srcpad, src_caps);
gst_caps_unref (src_caps);
buf = gst_buffer_new ();
gst_buffer_append_memory (buf,
gst_memory_new_wrapped (0, headers, headers_len, 0, headers_len, headers,
g_free));
gst_rtp_base_depayload_push (depayload, buf);
return TRUE;
/* ERRORS */
no_config:
{
GST_WARNING_OBJECT (depay, "caps without 'config' field with asf headers");
return FALSE;
}
no_packetsize:
{
GST_WARNING_OBJECT (depay, "caps without 'maxps' (packet size) field");
return FALSE;
}
invalid_packetsize:
{
GST_WARNING_OBJECT (depay, "packet size %u invalid", depay->packet_size);
return FALSE;
}
invalid_headers:
{
GST_WARNING_OBJECT (depay, "headers don't look like valid ASF headers");
g_free (headers);
return FALSE;
}
duplicate_header:
{
GST_DEBUG_OBJECT (depayload, "discarding duplicate header");
return TRUE;
}
refuse_renegotiation:
{
GST_WARNING_OBJECT (depayload, "cannot renegotiate to different header");
return FALSE;
}
}
static gint
field_size (guint8 field)
{
switch (field) {
/* DWORD - 32 bits */
case 3:
return 4;
/* WORD - 16 bits */
case 2:
return 2;
/* BYTE - 8 bits */
case 1:
return 1;
/* non-exitent */
case 0:
default:
return 0;
}
}
/* Set the padding field to te correct value as the spec
* says it should be se to 0 in the rtp packets
*/
static GstBuffer *
gst_rtp_asf_depay_update_padding (GstRtpAsfDepay * depayload, GstBuffer * buf)
{
GstBuffer *result;
GstMapInfo map;
guint8 *data;
gint offset = 0;
guint8 aux;
guint8 seq_type;
guint8 pad_type;
guint8 pkt_type;
gsize plen, padding;
plen = gst_buffer_get_size (buf);
if (plen == depayload->packet_size)
return buf;
padding = depayload->packet_size - plen;
GST_LOG_OBJECT (depayload,
"padding buffer size %" G_GSIZE_FORMAT " to packet size %d", plen,
depayload->packet_size);
result = gst_buffer_new_and_alloc (depayload->packet_size);
gst_buffer_map (result, &map, GST_MAP_READ);
data = map.data;
memset (data + plen, 0, padding);
gst_buffer_extract (buf, 0, data, plen);
gst_buffer_unref (buf);
aux = data[offset++];
if (aux & 0x80) {
guint8 err_len = 0;
if (aux & 0x60) {
GST_WARNING_OBJECT (depayload, "Error correction length type should be "
"set to 0");
/* this packet doesn't follow the spec */
gst_buffer_unmap (result, &map);
return result;
}
err_len = aux & 0x0F;
offset += err_len;
aux = data[offset++];
}
seq_type = (aux >> 1) & 0x3;
pad_type = (aux >> 3) & 0x3;
pkt_type = (aux >> 5) & 0x3;
offset += 1; /* skip property flags */
offset += field_size (pkt_type); /* skip packet length */
offset += field_size (seq_type); /* skip sequence field */
/* write padding */
switch (pad_type) {
/* DWORD */
case 3:
GST_WRITE_UINT32_LE (&(data[offset]), padding);
break;
/* WORD */
case 2:
GST_WRITE_UINT16_LE (&(data[offset]), padding);
break;
/* BYTE */
case 1:
data[offset] = (guint8) padding;
break;
/* non-existent */
case 0:
default:
break;
}
gst_buffer_unmap (result, &map);
return result;
}
/* Docs: 'RTSP Protocol PDF' document from http://sdp.ppona.com/ (page 8) */
static GstBuffer *
gst_rtp_asf_depay_process (GstRTPBaseDepayload * depayload, GstBuffer * buf)
{
GstRtpAsfDepay *depay;
const guint8 *payload;
GstBuffer *outbuf;
gboolean S, L, R, D, I;
guint payload_len, hdr_len, offset;
guint len_offs;
GstClockTime timestamp;
GstRTPBuffer rtpbuf = { NULL };
depay = GST_RTP_ASF_DEPAY (depayload);
/* flush remaining data on discont */
if (GST_BUFFER_IS_DISCONT (buf)) {
GST_LOG_OBJECT (depay, "got DISCONT");
gst_adapter_clear (depay->adapter);
depay->discont = TRUE;
}
gst_rtp_buffer_map (buf, GST_MAP_READ, &rtpbuf);
timestamp = GST_BUFFER_TIMESTAMP (buf);
payload_len = gst_rtp_buffer_get_payload_len (&rtpbuf);
payload = gst_rtp_buffer_get_payload (&rtpbuf);
offset = 0;
GST_LOG_OBJECT (depay, "got payload len of %u", payload_len);
do {
guint packet_len;
/* packet header is at least 4 bytes */
if (payload_len < 4)
goto too_small;
/* 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* |S|L|R|D|I|RES | Length/Offset |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Relative Timestamp (optional) |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Duration (optional) |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | LocationId (optional) |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
* S: packet contains a keyframe.
* L: If 1, Length/Offset contains length, else contains the byte offset
* of the fragment's first byte counted from the beginning of the
* complete ASF data packet.
* R: relative timestamp present
* D: duration present
* I: locationid present
*/
S = ((payload[0] & 0x80) != 0);
L = ((payload[0] & 0x40) != 0);
R = ((payload[0] & 0x20) != 0);
D = ((payload[0] & 0x10) != 0);
I = ((payload[0] & 0x08) != 0);
hdr_len = 4;
len_offs = (payload[1] << 16) | (payload[2] << 8) | payload[3];
if (R) {
GST_DEBUG ("Relative timestamp field present : %u",
GST_READ_UINT32_BE (payload + hdr_len));
hdr_len += 4;
}
if (D) {
GST_DEBUG ("Duration field present : %u",
GST_READ_UINT32_BE (payload + hdr_len));
hdr_len += 4;
}
if (I) {
GST_DEBUG ("LocationId field present : %u",
GST_READ_UINT32_BE (payload + hdr_len));
hdr_len += 4;
}
GST_LOG_OBJECT (depay, "S %d, L %d, R %d, D %d, I %d", S, L, R, D, I);
GST_LOG_OBJECT (depay, "payload_len:%d, hdr_len:%d, len_offs:%d",
payload_len, hdr_len, len_offs);
if (payload_len < hdr_len)
goto too_small;
/* skip headers */
payload_len -= hdr_len;
payload += hdr_len;
offset += hdr_len;
if (L) {
/* L bit set, len contains the length of the packet */
packet_len = len_offs;
} else {
/* else it contains an offset which we don't handle yet */
GST_LOG_OBJECT (depay, "We have a fragmented packet");
packet_len = payload_len;
}
if (packet_len > payload_len)
packet_len = payload_len;
GST_LOG_OBJECT (depay, "packet len %u, payload len %u, packet_size:%u",
packet_len, payload_len, depay->packet_size);
if (!L) {
guint available;
GstBuffer *sub;
/* Fragmented packet handling */
outbuf = NULL;
if (len_offs == (available = gst_adapter_available (depay->adapter))) {
/* fragment aligns with what we have, add it */
GST_LOG_OBJECT (depay, "collecting fragment");
sub =
gst_rtp_buffer_get_payload_subbuffer (&rtpbuf, offset, packet_len);
gst_adapter_push (depay->adapter, sub);
/* RTP marker bit M is set if this is last fragment */
if (gst_rtp_buffer_get_marker (&rtpbuf)) {
GST_LOG_OBJECT (depay, "last fragment, assembling packet");
outbuf =
gst_adapter_take_buffer (depay->adapter, available + packet_len);
}
} else {
if (available) {
GST_WARNING_OBJECT (depay, "Offset doesn't match previous data?!");
GST_DEBUG_OBJECT (depay, "clearing for re-sync");
gst_adapter_clear (depay->adapter);
} else
GST_DEBUG_OBJECT (depay, "waiting for start of packet");
}
} else {
GST_LOG_OBJECT (depay, "collecting packet");
outbuf =
gst_rtp_buffer_get_payload_subbuffer (&rtpbuf, offset, packet_len);
}
/* If we haven't completed a full ASF packet, return */
if (!outbuf)
return NULL;
outbuf = gst_rtp_asf_depay_update_padding (depay, outbuf);
if (!S)
GST_BUFFER_FLAG_SET (outbuf, GST_BUFFER_FLAG_DELTA_UNIT);
if (depay->discont) {
GST_LOG_OBJECT (depay, "setting DISCONT");
GST_BUFFER_FLAG_SET (outbuf, GST_BUFFER_FLAG_DISCONT);
depay->discont = FALSE;
}
GST_BUFFER_TIMESTAMP (outbuf) = timestamp;
gst_rtp_base_depayload_push (depayload, outbuf);
/* only apply the timestamp to the first buffer of this packet */
timestamp = -1;
/* skip packet data */
payload += packet_len;
offset += packet_len;
payload_len -= packet_len;
} while (payload_len > 0);
gst_rtp_buffer_unmap (&rtpbuf);
return NULL;
/* ERRORS */
too_small:
{
gst_rtp_buffer_unmap (&rtpbuf);
GST_WARNING_OBJECT (depayload, "Payload too small, expected at least 4 "
"bytes for header, but got only %d bytes", payload_len);
return NULL;
}
}
static GstStateChangeReturn
gst_rtp_asf_depay_change_state (GstElement * element, GstStateChange trans)
{
GstStateChangeReturn ret;
GstRtpAsfDepay *depay;
depay = GST_RTP_ASF_DEPAY (element);
switch (trans) {
case GST_STATE_CHANGE_READY_TO_PAUSED:
gst_adapter_clear (depay->adapter);
depay->discont = TRUE;
break;
default:
break;
}
ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, trans);
switch (trans) {
case GST_STATE_CHANGE_PAUSED_TO_READY:
gst_adapter_clear (depay->adapter);
break;
default:
break;
}
return ret;
}