gstreamer/gst/rtp/gstrtpamrdec.c

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/* GStreamer
* Copyright (C) <2005> Wim Taymans <wim@fluendo.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
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <gst/rtp/gstrtpbuffer.h>
#include <string.h>
#include "gstrtpamrdec.h"
/* references:
*
* RFC 3267 - Real-Time Transport Protocol (RTP) Payload Format and File Storage Format
* for the Adaptive Multi-Rate (AMR) and Adaptive Multi-Rate Wideband (AMR-WB) Audio
* Codecs.
*/
/* elementfactory information */
static GstElementDetails gst_rtp_amrdec_details = {
"RTP packet parser",
"Codec/Parser/Network",
"Extracts AMR audio from RTP packets (RFC 3267)",
"Wim Taymans <wim@fluendo.com>"
};
/* RtpAMRDec signals and args */
enum
{
/* FILL ME */
LAST_SIGNAL
};
enum
{
ARG_0,
ARG_FREQUENCY
};
/* input is an RTP packet
*
* params see RFC 3267, section 8.1
*/
static GstStaticPadTemplate gst_rtpamrdec_sink_template =
GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("application/x-rtp, "
"media = (string) \"audio\", "
"payload = (int) [ 96, 255 ], "
"clock-rate = (int) 8000, "
"encoding-name = (string) \"AMR\", "
"encoding-params = (string) \"1\", "
"octet-align = (string) \"1\", "
"crc = (string) { \"0\", \"1\" }, "
"robust-sorting = (string) \"0\", " "interleaving = (string) \"0\""
/* following options are not needed for a decoder
*
"mode-set = (int) [ 0, 7 ], "
"mode-change-period = (int) [ 1, MAX ], "
"mode-change-neighbor = (boolean) { TRUE, FALSE }, "
"maxptime = (int) [ 20, MAX ], "
"ptime = (int) [ 20, MAX ]"
*/
)
);
static GstStaticPadTemplate gst_rtpamrdec_src_template =
GST_STATIC_PAD_TEMPLATE ("src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("audio/AMR, " "channels = (int) 1," "rate = (int) 8000")
);
static void gst_rtpamrdec_class_init (GstRtpAMRDecClass * klass);
static void gst_rtpamrdec_base_init (GstRtpAMRDecClass * klass);
static void gst_rtpamrdec_init (GstRtpAMRDec * rtpamrdec);
static gboolean gst_rtpamrdec_sink_setcaps (GstPad * pad, GstCaps * caps);
static GstFlowReturn gst_rtpamrdec_chain (GstPad * pad, GstBuffer * buffer);
static void gst_rtpamrdec_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec);
static void gst_rtpamrdec_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec);
static GstStateChangeReturn gst_rtpamrdec_change_state (GstElement * element,
GstStateChange transition);
static GstElementClass *parent_class = NULL;
static GType
gst_rtpamrdec_get_type (void)
{
static GType rtpamrdec_type = 0;
if (!rtpamrdec_type) {
static const GTypeInfo rtpamrdec_info = {
sizeof (GstRtpAMRDecClass),
(GBaseInitFunc) gst_rtpamrdec_base_init,
NULL,
(GClassInitFunc) gst_rtpamrdec_class_init,
NULL,
NULL,
sizeof (GstRtpAMRDec),
0,
(GInstanceInitFunc) gst_rtpamrdec_init,
};
rtpamrdec_type =
g_type_register_static (GST_TYPE_ELEMENT, "GstRtpAMRDec",
&rtpamrdec_info, 0);
}
return rtpamrdec_type;
}
static void
gst_rtpamrdec_base_init (GstRtpAMRDecClass * klass)
{
GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
gst_element_class_add_pad_template (element_class,
gst_static_pad_template_get (&gst_rtpamrdec_src_template));
gst_element_class_add_pad_template (element_class,
gst_static_pad_template_get (&gst_rtpamrdec_sink_template));
gst_element_class_set_details (element_class, &gst_rtp_amrdec_details);
}
static void
gst_rtpamrdec_class_init (GstRtpAMRDecClass * klass)
{
GObjectClass *gobject_class;
GstElementClass *gstelement_class;
gobject_class = (GObjectClass *) klass;
gstelement_class = (GstElementClass *) klass;
parent_class = g_type_class_ref (GST_TYPE_ELEMENT);
gobject_class->set_property = gst_rtpamrdec_set_property;
gobject_class->get_property = gst_rtpamrdec_get_property;
gstelement_class->change_state = gst_rtpamrdec_change_state;
}
static void
gst_rtpamrdec_init (GstRtpAMRDec * rtpamrdec)
{
rtpamrdec->srcpad =
gst_pad_new_from_template (gst_static_pad_template_get
(&gst_rtpamrdec_src_template), "src");
gst_element_add_pad (GST_ELEMENT (rtpamrdec), rtpamrdec->srcpad);
rtpamrdec->sinkpad =
gst_pad_new_from_template (gst_static_pad_template_get
(&gst_rtpamrdec_sink_template), "sink");
gst_pad_set_setcaps_function (rtpamrdec->sinkpad, gst_rtpamrdec_sink_setcaps);
gst_pad_set_chain_function (rtpamrdec->sinkpad, gst_rtpamrdec_chain);
gst_element_add_pad (GST_ELEMENT (rtpamrdec), rtpamrdec->sinkpad);
}
static gboolean
gst_rtpamrdec_sink_setcaps (GstPad * pad, GstCaps * caps)
{
GstStructure *structure;
GstCaps *srccaps;
GstRtpAMRDec *rtpamrdec;
const gchar *params;
const gchar *str;
rtpamrdec = GST_RTP_AMR_DEC (GST_OBJECT_PARENT (pad));
structure = gst_caps_get_structure (caps, 0);
if (!(str = gst_structure_get_string (structure, "octet-align")))
rtpamrdec->octet_align = FALSE;
else
rtpamrdec->octet_align = (atoi (str) == 1);
if (!(str = gst_structure_get_string (structure, "crc")))
rtpamrdec->crc = FALSE;
else
rtpamrdec->crc = (atoi (str) == 1);
if (rtpamrdec->crc) {
/* crc mode implies octet aligned mode */
rtpamrdec->octet_align = TRUE;
}
if (!(str = gst_structure_get_string (structure, "robust-sorting")))
rtpamrdec->robust_sorting = FALSE;
else
rtpamrdec->robust_sorting = (atoi (str) == 1);
if (rtpamrdec->robust_sorting) {
/* robust_sorting mode implies octet aligned mode */
rtpamrdec->octet_align = TRUE;
}
if (!(str = gst_structure_get_string (structure, "interleaving")))
rtpamrdec->interleaving = FALSE;
else
rtpamrdec->interleaving = (atoi (str) == 1);
if (rtpamrdec->interleaving) {
/* interleaving mode implies octet aligned mode */
rtpamrdec->octet_align = TRUE;
}
if (!(params = gst_structure_get_string (structure, "encoding-params")))
rtpamrdec->channels = 1;
else {
rtpamrdec->channels = atoi (params);
}
if (!gst_structure_get_int (structure, "clock-rate", &rtpamrdec->rate))
rtpamrdec->rate = 8000;
/* we require 1 channel, 8000 Hz, octet aligned, no CRC,
* no robust sorting, no interleaving for now */
if (rtpamrdec->channels != 1)
return FALSE;
if (rtpamrdec->rate != 8000)
return FALSE;
if (rtpamrdec->octet_align != TRUE)
return FALSE;
if (rtpamrdec->robust_sorting != FALSE)
return FALSE;
if (rtpamrdec->interleaving != FALSE)
return FALSE;
srccaps = gst_caps_new_simple ("audio/AMR",
"channels", G_TYPE_INT, rtpamrdec->channels,
"rate", G_TYPE_INT, rtpamrdec->rate, NULL);
gst_pad_set_caps (rtpamrdec->srcpad, srccaps);
gst_caps_unref (srccaps);
rtpamrdec->negotiated = TRUE;
return TRUE;
}
/* -1 is invalid */
static gint frame_size[16] = {
12, 13, 15, 17, 19, 20, 26, 31,
5, -1, -1, -1, -1, -1, -1, 0
};
static GstFlowReturn
gst_rtpamrdec_chain (GstPad * pad, GstBuffer * buf)
{
GstRtpAMRDec *rtpamrdec;
GstBuffer *outbuf;
GstFlowReturn ret;
rtpamrdec = GST_RTP_AMR_DEC (GST_OBJECT_PARENT (pad));
if (!rtpamrdec->negotiated)
goto not_negotiated;
if (!gst_rtpbuffer_validate (buf))
goto bad_packet;
/* when we get here, 1 channel, 8000 Hz, octet aligned, no CRC,
* no robust sorting, no interleaving data is to be parsed */
{
gint payload_len;
guint8 *payload, *p, *dp;
guint32 timestamp;
guint8 CMR;
gint i, num_packets, num_nonempty_packets;
gint amr_len;
gint ILL, ILP;
payload_len = gst_rtpbuffer_get_payload_len (buf);
/* need at least 2 bytes for the header */
if (payload_len < 2)
goto bad_packet;
payload = gst_rtpbuffer_get_payload (buf);
/* parse CMR. The CMR is used by the sender to request
* a new encoding mode.
*
* 0 1 2 3 4 5 6 7
* +-+-+-+-+-+-+-+-+
* | CMR |R|R|R|R|
* +-+-+-+-+-+-+-+-+
*/
CMR = (payload[0] & 0xf0) >> 4;
/* strip CMR header now, pack FT and the data for the decoder */
payload_len -= 1;
payload += 1;
if (rtpamrdec->interleaving) {
ILL = (payload[0] & 0xf0) >> 4;
ILP = (payload[0] & 0x0f);
payload_len -= 1;
payload += 1;
if (ILP > ILL)
goto bad_packet;
}
/*
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6
* +-+-+-+-+-+-+-+-+..
* |F| FT |Q|P|P| more FT..
* +-+-+-+-+-+-+-+-+..
*/
/* count number of packets by counting the FTs. Also
* count number of amr data bytes and number of non-empty
* packets (this is also the number of CRCs if present). */
amr_len = 0;
num_nonempty_packets = 0;
num_packets = 0;
for (i = 0; i < payload_len; i++) {
gint fr_size;
guint8 FT;
FT = (payload[i] & 0x78) >> 3;
fr_size = frame_size[FT];
if (fr_size == -1)
goto bad_packet;
if (fr_size > 0) {
amr_len += fr_size;
num_nonempty_packets++;
}
num_packets++;
if ((payload[i] & 0x80) == 0)
break;
}
/* this is impossible */
if (num_packets == payload_len)
goto bad_packet;
if (rtpamrdec->crc) {
/* data len + CRC len + header bytes should be smaller than payload_len */
if (num_packets + num_nonempty_packets + amr_len > payload_len)
goto bad_packet;
} else {
/* data len + header bytes should be smaller than payload_len */
if (num_packets + amr_len > payload_len)
goto bad_packet;
}
timestamp = gst_rtpbuffer_get_timestamp (buf);
outbuf = gst_buffer_new_and_alloc (payload_len);
GST_BUFFER_TIMESTAMP (outbuf) = timestamp * GST_SECOND / rtpamrdec->rate;
/* point to destination */
p = GST_BUFFER_DATA (outbuf);
/* point to first data packet */
dp = payload + num_packets;
if (rtpamrdec->crc) {
/* skip CRC if present */
dp += num_nonempty_packets;
}
for (i = 0; i < num_packets; i++) {
gint fr_size;
fr_size = frame_size[(payload[i] & 0x78) >> 3];
if (fr_size > 0) {
/* copy FT */
*p++ = payload[i];
/* copy data packet, FIXME, calc CRC here. */
memcpy (p, dp, fr_size);
p += fr_size;
dp += fr_size;
}
}
gst_buffer_set_caps (outbuf, GST_PAD_CAPS (rtpamrdec->srcpad));
GST_DEBUG ("gst_rtpamrdec_chain: pushing buffer of size %d",
GST_BUFFER_SIZE (outbuf));
ret = gst_pad_push (rtpamrdec->srcpad, outbuf);
gst_buffer_unref (buf);
}
return ret;
not_negotiated:
{
GST_ELEMENT_ERROR (rtpamrdec, STREAM, NOT_IMPLEMENTED,
("not negotiated"), (NULL));
gst_buffer_unref (buf);
return GST_FLOW_NOT_NEGOTIATED;
}
bad_packet:
{
GST_ELEMENT_WARNING (rtpamrdec, STREAM, DECODE,
("amr packet did not validate"), (NULL));
gst_buffer_unref (buf);
return GST_FLOW_OK;
}
}
static void
gst_rtpamrdec_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec)
{
GstRtpAMRDec *rtpamrdec;
rtpamrdec = GST_RTP_AMR_DEC (object);
switch (prop_id) {
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gst_rtpamrdec_get_property (GObject * object, guint prop_id, GValue * value,
GParamSpec * pspec)
{
GstRtpAMRDec *rtpamrdec;
rtpamrdec = GST_RTP_AMR_DEC (object);
switch (prop_id) {
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static GstStateChangeReturn
gst_rtpamrdec_change_state (GstElement * element, GstStateChange transition)
{
GstRtpAMRDec *rtpamrdec;
GstStateChangeReturn ret;
rtpamrdec = GST_RTP_AMR_DEC (element);
switch (transition) {
case GST_STATE_CHANGE_NULL_TO_READY:
break;
case GST_STATE_CHANGE_READY_TO_PAUSED:
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_rtpamrdec_plugin_init (GstPlugin * plugin)
{
return gst_element_register (plugin, "rtpamrdec",
GST_RANK_NONE, GST_TYPE_RTP_AMR_DEC);
}