gstreamer/gst/rtp/gstrtph263depay.c
2012-11-04 00:07:18 +00:00

377 lines
12 KiB
C

/* GStreamer
*
* Copyright 2007 Nokia Corporation
* Copyright 2007 Collabora Ltd,
* @author: Philippe Kalaf <philippe.kalaf@collabora.co.uk>
*
* Copyright (C) <2005> Wim Taymans <wim.taymans@gmail.com>
* <2007> Edward Hervey <bilboed@bilboed.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 <string.h>
#include <gst/rtp/gstrtpbuffer.h>
#include "gstrtph263depay.h"
GST_DEBUG_CATEGORY_STATIC (rtph263depay_debug);
#define GST_CAT_DEFAULT (rtph263depay_debug)
#define GST_RFC2190A_HEADER_LEN 4
#define GST_RFC2190B_HEADER_LEN 8
#define GST_RFC2190C_HEADER_LEN 12
static GstStaticPadTemplate gst_rtp_h263_depay_src_template =
GST_STATIC_PAD_TEMPLATE ("src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("video/x-h263, "
"variant = (string) \"itu\", " "h263version = (string) \"h263\"")
);
static GstStaticPadTemplate gst_rtp_h263_depay_sink_template =
GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("application/x-rtp, "
"media = (string) \"video\", "
"payload = (int) " GST_RTP_PAYLOAD_H263_STRING ", "
"clock-rate = (int) 90000, " "encoding-name = (string) \"H263\"; "
"application/x-rtp, "
"media = (string) \"video\", "
"payload = (int) " GST_RTP_PAYLOAD_DYNAMIC_STRING ", "
"clock-rate = (int) 90000, " "encoding-name = (string) \"H263\"")
);
#define gst_rtp_h263_depay_parent_class parent_class
G_DEFINE_TYPE (GstRtpH263Depay, gst_rtp_h263_depay,
GST_TYPE_RTP_BASE_DEPAYLOAD);
static void gst_rtp_h263_depay_finalize (GObject * object);
static GstStateChangeReturn gst_rtp_h263_depay_change_state (GstElement *
element, GstStateChange transition);
static GstBuffer *gst_rtp_h263_depay_process (GstRTPBaseDepayload * depayload,
GstBuffer * buf);
gboolean gst_rtp_h263_depay_setcaps (GstRTPBaseDepayload * filter,
GstCaps * caps);
static void
gst_rtp_h263_depay_class_init (GstRtpH263DepayClass * klass)
{
GObjectClass *gobject_class;
GstElementClass *gstelement_class;
GstRTPBaseDepayloadClass *gstrtpbasedepayload_class;
GST_DEBUG_CATEGORY_INIT (rtph263depay_debug, "rtph263depay", 0,
"H263 Video RTP Depayloader");
gobject_class = (GObjectClass *) klass;
gstelement_class = (GstElementClass *) klass;
gstrtpbasedepayload_class = (GstRTPBaseDepayloadClass *) klass;
gobject_class->finalize = gst_rtp_h263_depay_finalize;
gstelement_class->change_state = gst_rtp_h263_depay_change_state;
gst_element_class_add_pad_template (gstelement_class,
gst_static_pad_template_get (&gst_rtp_h263_depay_src_template));
gst_element_class_add_pad_template (gstelement_class,
gst_static_pad_template_get (&gst_rtp_h263_depay_sink_template));
gst_element_class_set_static_metadata (gstelement_class,
"RTP H263 depayloader", "Codec/Depayloader/Network/RTP",
"Extracts H263 video from RTP packets (RFC 2190)",
"Philippe Kalaf <philippe.kalaf@collabora.co.uk>, "
"Edward Hervey <bilboed@bilboed.com>");
gstrtpbasedepayload_class->process = gst_rtp_h263_depay_process;
gstrtpbasedepayload_class->set_caps = gst_rtp_h263_depay_setcaps;
}
static void
gst_rtp_h263_depay_init (GstRtpH263Depay * rtph263depay)
{
rtph263depay->adapter = gst_adapter_new ();
rtph263depay->offset = 0;
rtph263depay->leftover = 0;
}
static void
gst_rtp_h263_depay_finalize (GObject * object)
{
GstRtpH263Depay *rtph263depay;
rtph263depay = GST_RTP_H263_DEPAY (object);
g_object_unref (rtph263depay->adapter);
rtph263depay->adapter = NULL;
G_OBJECT_CLASS (parent_class)->finalize (object);
}
gboolean
gst_rtp_h263_depay_setcaps (GstRTPBaseDepayload * filter, GstCaps * caps)
{
GstCaps *srccaps;
GstStructure *structure = gst_caps_get_structure (caps, 0);
gint clock_rate;
if (!gst_structure_get_int (structure, "clock-rate", &clock_rate))
clock_rate = 90000; /* default */
filter->clock_rate = clock_rate;
srccaps = gst_caps_new_simple ("video/x-h263",
"variant", G_TYPE_STRING, "itu",
"h263version", G_TYPE_STRING, "h263", NULL);
gst_pad_set_caps (GST_RTP_BASE_DEPAYLOAD_SRCPAD (filter), srccaps);
gst_caps_unref (srccaps);
return TRUE;
}
static GstBuffer *
gst_rtp_h263_depay_process (GstRTPBaseDepayload * depayload, GstBuffer * buf)
{
GstRtpH263Depay *rtph263depay;
GstBuffer *outbuf;
gint payload_len;
guint8 *payload;
guint header_len;
guint SBIT, EBIT;
gboolean F, P, M;
gboolean I;
GstRTPBuffer rtp = { NULL };
rtph263depay = GST_RTP_H263_DEPAY (depayload);
/* flush remaining data on discont */
if (GST_BUFFER_IS_DISCONT (buf)) {
GST_LOG_OBJECT (depayload, "Discont buffer, flushing adapter");
gst_adapter_clear (rtph263depay->adapter);
rtph263depay->offset = 0;
rtph263depay->leftover = 0;
rtph263depay->start = FALSE;
}
gst_rtp_buffer_map (buf, GST_MAP_READ, &rtp);
payload_len = gst_rtp_buffer_get_payload_len (&rtp);
payload = gst_rtp_buffer_get_payload (&rtp);
M = gst_rtp_buffer_get_marker (&rtp);
/* Let's see what mode we are using */
F = (payload[0] & 0x80) == 0x80;
P = (payload[0] & 0x40) == 0x40;
/* Bit shifting */
SBIT = (payload[0] & 0x38) >> 3;
EBIT = (payload[0] & 0x07);
/* Figure out header length and I-flag */
if (F == 0) {
/* F == 0 and P == 0 or 1
* mode A */
header_len = GST_RFC2190A_HEADER_LEN;
GST_LOG ("Mode A");
/* 0 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
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* |F|P|SBIT |EBIT | SRC |I|U|S|A|R |DBQ| TRB | TR |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
I = (payload[1] & 0x10) == 0x10;
} else {
if (P == 0) {
/* F == 1 and P == 0
* mode B */
header_len = GST_RFC2190B_HEADER_LEN;
GST_LOG ("Mode B");
/* 0 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
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* |F|P|SBIT |EBIT | SRC | QUANT | GOBN | MBA |R |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* |I|U|S|A| HMV1 | VMV1 | HMV2 | VMV2 |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
I = (payload[4] & 0x80) == 0x80;
} else {
/* F == 1 and P == 1
* mode C */
header_len = GST_RFC2190C_HEADER_LEN;
GST_LOG ("Mode C");
/* 0 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
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* |F|P|SBIT |EBIT | SRC | QUANT | GOBN | MBA |R |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* |I|U|S|A| HMV1 | VMV1 | HMV2 | VMV2 |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | RR |DBQ| TRB | TR |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
I = (payload[4] & 0x80) == 0x80;
}
}
GST_LOG ("F/P/M/I : %d/%d/%d/%d", F, P, M, I);
GST_LOG ("SBIT : %d , EBIT : %d", SBIT, EBIT);
GST_LOG ("payload_len : %d, header_len : %d , leftover : 0x%x",
payload_len, header_len, rtph263depay->leftover);
/* skip header */
payload += header_len;
payload_len -= header_len;
if (!rtph263depay->start) {
/* do not skip this fragment if it is a Mode A with picture start code */
if (!F && payload_len > 4 && (GST_READ_UINT32_BE (payload) >> 10 == 0x20)) {
GST_DEBUG ("Mode A with PSC => frame start");
rtph263depay->start = TRUE;
if (! !(payload[4] & 0x02) != I) {
GST_DEBUG ("Wrong Picture Coding Type Flag in rtp header");
I = !I;
}
rtph263depay->psc_I = I;
} else {
GST_DEBUG ("no frame start yet, skipping payload");
goto skip;
}
}
/* only trust I info from Mode A starting packet
* from buggy payloaders or hw */
I = rtph263depay->psc_I;
if (SBIT) {
/* take the leftover and merge it at the beginning, FIXME make the buffer
* data writable. */
GST_LOG ("payload[0] : 0x%x", payload[0]);
payload[0] &= 0xFF >> SBIT;
GST_LOG ("payload[0] : 0x%x", payload[0]);
payload[0] |= rtph263depay->leftover;
GST_LOG ("payload[0] : 0x%x", payload[0]);
rtph263depay->leftover = 0;
rtph263depay->offset = 0;
}
if (!EBIT) {
GstBuffer *tmp;
/* Take the entire buffer */
tmp = gst_rtp_buffer_get_payload_subbuffer (&rtp, header_len, payload_len);
gst_adapter_push (rtph263depay->adapter, tmp);
} else {
GstBuffer *tmp;
/* Take the entire buffer except for the last byte */
tmp = gst_rtp_buffer_get_payload_subbuffer (&rtp, header_len,
payload_len - 1);
gst_adapter_push (rtph263depay->adapter, tmp);
/* Put the last byte into the leftover */
GST_DEBUG ("payload[payload_len - 1] : 0x%x", payload[payload_len - 1]);
GST_DEBUG ("mask : 0x%x", 0xFF << EBIT);
rtph263depay->leftover = (payload[payload_len - 1] >> EBIT) << EBIT;
rtph263depay->offset = 1;
GST_DEBUG ("leftover : 0x%x", rtph263depay->leftover);
}
skip:
if (M) {
if (rtph263depay->start) {
/* frame is completed */
guint avail;
if (rtph263depay->offset) {
/* push in the leftover */
GstBuffer *buf = gst_buffer_new_and_alloc (1);
GST_DEBUG ("Pushing leftover in adapter");
gst_buffer_fill (buf, 0, &rtph263depay->leftover, 1);
gst_adapter_push (rtph263depay->adapter, buf);
}
avail = gst_adapter_available (rtph263depay->adapter);
outbuf = gst_adapter_take_buffer (rtph263depay->adapter, avail);
if (I)
GST_BUFFER_FLAG_SET (outbuf, GST_BUFFER_FLAG_DELTA_UNIT);
GST_DEBUG ("Pushing out a buffer of %d bytes", avail);
gst_rtp_base_depayload_push (depayload, outbuf);
rtph263depay->offset = 0;
rtph263depay->leftover = 0;
rtph263depay->start = FALSE;
} else {
rtph263depay->start = TRUE;
}
}
gst_rtp_buffer_unmap (&rtp);
return NULL;
}
static GstStateChangeReturn
gst_rtp_h263_depay_change_state (GstElement * element,
GstStateChange transition)
{
GstRtpH263Depay *rtph263depay;
GstStateChangeReturn ret;
rtph263depay = GST_RTP_H263_DEPAY (element);
switch (transition) {
case GST_STATE_CHANGE_NULL_TO_READY:
break;
case GST_STATE_CHANGE_READY_TO_PAUSED:
gst_adapter_clear (rtph263depay->adapter);
rtph263depay->start = TRUE;
break;
default:
break;
}
ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
switch (transition) {
case GST_STATE_CHANGE_READY_TO_NULL:
break;
default:
break;
}
return ret;
}
gboolean
gst_rtp_h263_depay_plugin_init (GstPlugin * plugin)
{
return gst_element_register (plugin, "rtph263depay",
GST_RANK_SECONDARY, GST_TYPE_RTP_H263_DEPAY);
}