gstreamer/subprojects/gst-plugins-good/gst/rtp/gstrtpamrpay.c
Sebastian Dröge b0afaffc5d rtp: In payloaders map the RTP marker flag to the corresponding buffer flag
This allows downstream of a payloader to know the RTP header's marker
flag without first having to map the buffer and parse the RTP header.

Especially inside RTP header extension implementations this can be
useful to decide which packet corresponds to e.g. the last packet of a
video frame.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1776>
2022-02-28 10:13:11 +00:00

462 lines
14 KiB
C

/* GStreamer
* Copyright (C) <2005> 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.
*/
/**
* SECTION:element-rtpamrpay
* @title: rtpamrpay
* @see_also: rtpamrdepay
*
* Payload AMR audio into RTP packets according to RFC 3267.
* For detailed information see: http://www.rfc-editor.org/rfc/rfc3267.txt
*
* ## Example pipeline
* |[
* gst-launch-1.0 -v audiotestsrc ! amrnbenc ! rtpamrpay ! udpsink
* ]| This example pipeline will encode and payload an AMR stream. Refer to
* the rtpamrdepay example to depayload and decode the RTP stream.
*
*/
/* 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.
*
* ETSI TS 126 201 V6.0.0 (2004-12) - Digital cellular telecommunications system (Phase 2+);
* Universal Mobile Telecommunications System (UMTS);
* AMR speech codec, wideband;
* Frame structure
* (3GPP TS 26.201 version 6.0.0 Release 6)
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <string.h>
#include <gst/rtp/gstrtpbuffer.h>
#include <gst/audio/audio.h>
#include "gstrtpelements.h"
#include "gstrtpamrpay.h"
#include "gstrtputils.h"
GST_DEBUG_CATEGORY_STATIC (rtpamrpay_debug);
#define GST_CAT_DEFAULT (rtpamrpay_debug)
static GstStaticPadTemplate gst_rtp_amr_pay_sink_template =
GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("audio/AMR, channels=(int)1, rate=(int)8000; "
"audio/AMR-WB, channels=(int)1, rate=(int)16000")
);
static GstStaticPadTemplate gst_rtp_amr_pay_src_template =
GST_STATIC_PAD_TEMPLATE ("src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("application/x-rtp, "
"media = (string) \"audio\", "
"payload = (int) " GST_RTP_PAYLOAD_DYNAMIC_STRING ", "
"clock-rate = (int) 8000, "
"encoding-name = (string) \"AMR\", "
"encoding-params = (string) \"1\", "
"octet-align = (string) \"1\", "
"crc = (string) \"0\", "
"robust-sorting = (string) \"0\", "
"interleaving = (string) \"0\", "
"mode-set = (int) [ 0, 7 ], "
"mode-change-period = (int) [ 1, MAX ], "
"mode-change-neighbor = (string) { \"0\", \"1\" }, "
"maxptime = (int) [ 20, MAX ], " "ptime = (int) [ 20, MAX ];"
"application/x-rtp, "
"media = (string) \"audio\", "
"payload = (int) " GST_RTP_PAYLOAD_DYNAMIC_STRING ", "
"clock-rate = (int) 16000, "
"encoding-name = (string) \"AMR-WB\", "
"encoding-params = (string) \"1\", "
"octet-align = (string) \"1\", "
"crc = (string) \"0\", "
"robust-sorting = (string) \"0\", "
"interleaving = (string) \"0\", "
"mode-set = (int) [ 0, 7 ], "
"mode-change-period = (int) [ 1, MAX ], "
"mode-change-neighbor = (string) { \"0\", \"1\" }, "
"maxptime = (int) [ 20, MAX ], " "ptime = (int) [ 20, MAX ]")
);
static gboolean gst_rtp_amr_pay_setcaps (GstRTPBasePayload * basepayload,
GstCaps * caps);
static GstFlowReturn gst_rtp_amr_pay_handle_buffer (GstRTPBasePayload * pad,
GstBuffer * buffer);
static GstStateChangeReturn
gst_rtp_amr_pay_change_state (GstElement * element, GstStateChange transition);
#define gst_rtp_amr_pay_parent_class parent_class
G_DEFINE_TYPE (GstRtpAMRPay, gst_rtp_amr_pay, GST_TYPE_RTP_BASE_PAYLOAD);
GST_ELEMENT_REGISTER_DEFINE_WITH_CODE (rtpamrpay, "rtpamrpay",
GST_RANK_SECONDARY, GST_TYPE_RTP_AMR_PAY, rtp_element_init (plugin));
static void
gst_rtp_amr_pay_class_init (GstRtpAMRPayClass * klass)
{
GstElementClass *gstelement_class;
GstRTPBasePayloadClass *gstrtpbasepayload_class;
gstelement_class = (GstElementClass *) klass;
gstrtpbasepayload_class = (GstRTPBasePayloadClass *) klass;
gstelement_class->change_state = gst_rtp_amr_pay_change_state;
gst_element_class_add_static_pad_template (gstelement_class,
&gst_rtp_amr_pay_src_template);
gst_element_class_add_static_pad_template (gstelement_class,
&gst_rtp_amr_pay_sink_template);
gst_element_class_set_static_metadata (gstelement_class, "RTP AMR payloader",
"Codec/Payloader/Network/RTP",
"Payload-encode AMR or AMR-WB audio into RTP packets (RFC 3267)",
"Wim Taymans <wim.taymans@gmail.com>");
gstrtpbasepayload_class->set_caps = gst_rtp_amr_pay_setcaps;
gstrtpbasepayload_class->handle_buffer = gst_rtp_amr_pay_handle_buffer;
GST_DEBUG_CATEGORY_INIT (rtpamrpay_debug, "rtpamrpay", 0,
"AMR/AMR-WB RTP Payloader");
}
static void
gst_rtp_amr_pay_init (GstRtpAMRPay * rtpamrpay)
{
}
static void
gst_rtp_amr_pay_reset (GstRtpAMRPay * pay)
{
pay->next_rtp_time = 0;
pay->first_ts = GST_CLOCK_TIME_NONE;
pay->first_rtp_time = 0;
}
static gboolean
gst_rtp_amr_pay_setcaps (GstRTPBasePayload * basepayload, GstCaps * caps)
{
GstRtpAMRPay *rtpamrpay;
gboolean res;
const GstStructure *s;
const gchar *str;
rtpamrpay = GST_RTP_AMR_PAY (basepayload);
/* figure out the mode Narrow or Wideband */
s = gst_caps_get_structure (caps, 0);
if ((str = gst_structure_get_name (s))) {
if (strcmp (str, "audio/AMR") == 0)
rtpamrpay->mode = GST_RTP_AMR_P_MODE_NB;
else if (strcmp (str, "audio/AMR-WB") == 0)
rtpamrpay->mode = GST_RTP_AMR_P_MODE_WB;
else
goto wrong_type;
} else
goto wrong_type;
if (rtpamrpay->mode == GST_RTP_AMR_P_MODE_NB)
gst_rtp_base_payload_set_options (basepayload, "audio", TRUE, "AMR", 8000);
else
gst_rtp_base_payload_set_options (basepayload, "audio", TRUE, "AMR-WB",
16000);
res = gst_rtp_base_payload_set_outcaps (basepayload,
"encoding-params", G_TYPE_STRING, "1", "octet-align", G_TYPE_STRING, "1",
/* don't set the defaults
*
* "crc", G_TYPE_STRING, "0",
* "robust-sorting", G_TYPE_STRING, "0",
* "interleaving", G_TYPE_STRING, "0",
*/
NULL);
return res;
/* ERRORS */
wrong_type:
{
GST_ERROR_OBJECT (rtpamrpay, "unsupported media type '%s'",
GST_STR_NULL (str));
return FALSE;
}
}
static void
gst_rtp_amr_pay_recalc_rtp_time (GstRtpAMRPay * rtpamrpay,
GstClockTime timestamp)
{
/* re-sync rtp time */
if (GST_CLOCK_TIME_IS_VALID (rtpamrpay->first_ts) &&
GST_CLOCK_TIME_IS_VALID (timestamp) && timestamp >= rtpamrpay->first_ts) {
GstClockTime diff;
guint32 rtpdiff;
/* interpolate to reproduce gap from start, rather than intermediate
* intervals to avoid roundup accumulation errors */
diff = timestamp - rtpamrpay->first_ts;
rtpdiff = ((diff / GST_MSECOND) * 8) <<
(rtpamrpay->mode == GST_RTP_AMR_P_MODE_WB);
rtpamrpay->next_rtp_time = rtpamrpay->first_rtp_time + rtpdiff;
GST_DEBUG_OBJECT (rtpamrpay,
"elapsed time %" GST_TIME_FORMAT ", rtp %" G_GUINT32_FORMAT ", "
"new offset %" G_GUINT32_FORMAT, GST_TIME_ARGS (diff), rtpdiff,
rtpamrpay->next_rtp_time);
}
}
/* -1 is invalid */
static const gint nb_frame_size[16] = {
12, 13, 15, 17, 19, 20, 26, 31,
5, -1, -1, -1, -1, -1, -1, 0
};
static const gint wb_frame_size[16] = {
17, 23, 32, 36, 40, 46, 50, 58,
60, 5, -1, -1, -1, -1, -1, 0
};
static GstFlowReturn
gst_rtp_amr_pay_handle_buffer (GstRTPBasePayload * basepayload,
GstBuffer * buffer)
{
GstRtpAMRPay *rtpamrpay;
const gint *frame_size;
GstFlowReturn ret;
guint payload_len;
GstMapInfo map;
GstBuffer *outbuf;
guint8 *payload, *ptr, *payload_amr;
GstClockTime timestamp, duration;
guint packet_len, mtu;
gint i, num_packets, num_nonempty_packets;
gint amr_len;
gboolean sid = FALSE;
GstRTPBuffer rtp = { NULL };
rtpamrpay = GST_RTP_AMR_PAY (basepayload);
mtu = GST_RTP_BASE_PAYLOAD_MTU (rtpamrpay);
gst_buffer_map (buffer, &map, GST_MAP_READ);
timestamp = GST_BUFFER_PTS (buffer);
duration = GST_BUFFER_DURATION (buffer);
/* setup frame size pointer */
if (rtpamrpay->mode == GST_RTP_AMR_P_MODE_NB)
frame_size = nb_frame_size;
else
frame_size = wb_frame_size;
GST_DEBUG_OBJECT (basepayload, "got %" G_GSIZE_FORMAT " bytes", map.size);
/* FIXME, only
* octet aligned, no interleaving, single channel, no CRC,
* no robust-sorting. To fix this you need to implement the downstream
* negotiation function. */
/* first count number of packets and total amr frame size */
amr_len = num_packets = num_nonempty_packets = 0;
for (i = 0; i < map.size; i++) {
guint8 FT;
gint fr_size;
FT = (map.data[i] & 0x78) >> 3;
fr_size = frame_size[FT];
GST_DEBUG_OBJECT (basepayload, "frame type %d, frame size %d", FT, fr_size);
/* FIXME, we don't handle this yet.. */
if (fr_size <= 0)
goto wrong_size;
if (fr_size == 5)
sid = TRUE;
amr_len += fr_size;
num_nonempty_packets++;
num_packets++;
i += fr_size;
}
if (amr_len > map.size)
goto incomplete_frame;
/* we need one extra byte for the CMR, the ToC is in the input
* data */
payload_len = map.size + 1;
/* get packet len to check against MTU */
packet_len = gst_rtp_buffer_calc_packet_len (payload_len, 0, 0);
if (packet_len > mtu)
goto too_big;
/* now alloc output buffer */
outbuf =
gst_rtp_base_payload_allocate_output_buffer (basepayload, payload_len, 0,
0);
gst_rtp_buffer_map (outbuf, GST_MAP_WRITE, &rtp);
/* copy timestamp */
GST_BUFFER_PTS (outbuf) = timestamp;
if (duration != GST_CLOCK_TIME_NONE)
GST_BUFFER_DURATION (outbuf) = duration;
else {
GST_BUFFER_DURATION (outbuf) = num_packets * 20 * GST_MSECOND;
}
if (GST_BUFFER_IS_DISCONT (buffer)) {
GST_DEBUG_OBJECT (basepayload, "discont, setting marker bit");
GST_BUFFER_FLAG_SET (outbuf, GST_BUFFER_FLAG_DISCONT);
GST_BUFFER_FLAG_SET (outbuf, GST_BUFFER_FLAG_MARKER);
gst_rtp_buffer_set_marker (&rtp, TRUE);
gst_rtp_amr_pay_recalc_rtp_time (rtpamrpay, timestamp);
}
if (G_UNLIKELY (sid)) {
gst_rtp_amr_pay_recalc_rtp_time (rtpamrpay, timestamp);
}
/* perfect rtptime */
if (G_UNLIKELY (!GST_CLOCK_TIME_IS_VALID (rtpamrpay->first_ts))) {
rtpamrpay->first_ts = timestamp;
rtpamrpay->first_rtp_time = rtpamrpay->next_rtp_time;
}
GST_BUFFER_OFFSET (outbuf) = rtpamrpay->next_rtp_time;
rtpamrpay->next_rtp_time +=
(num_packets * 160) << (rtpamrpay->mode == GST_RTP_AMR_P_MODE_WB);
/* get payload, this is now writable */
payload = gst_rtp_buffer_get_payload (&rtp);
/* 0 1 2 3 4 5 6 7
* +-+-+-+-+-+-+-+-+
* | CMR |R|R|R|R|
* +-+-+-+-+-+-+-+-+
*/
payload[0] = 0xF0; /* CMR, no specific mode requested */
/* this is where we copy the AMR data, after num_packets FTs and the
* CMR. */
payload_amr = payload + num_packets + 1;
/* copy data in payload, first we copy all the FTs then all
* the AMR data. The last FT has to have the F flag cleared. */
ptr = map.data;
for (i = 1; i <= num_packets; i++) {
guint8 FT;
gint fr_size;
/* 0 1 2 3 4 5 6 7
* +-+-+-+-+-+-+-+-+
* |F| FT |Q|P|P| more FT...
* +-+-+-+-+-+-+-+-+
*/
FT = (*ptr & 0x78) >> 3;
fr_size = frame_size[FT];
if (i == num_packets)
/* last packet, clear F flag */
payload[i] = *ptr & 0x7f;
else
/* set F flag */
payload[i] = *ptr | 0x80;
memcpy (payload_amr, &ptr[1], fr_size);
/* all sizes are > 0 since we checked for that above */
ptr += fr_size + 1;
payload_amr += fr_size;
}
gst_buffer_unmap (buffer, &map);
gst_rtp_buffer_unmap (&rtp);
gst_rtp_copy_audio_meta (rtpamrpay, outbuf, buffer);
gst_buffer_unref (buffer);
ret = gst_rtp_base_payload_push (basepayload, outbuf);
return ret;
/* ERRORS */
wrong_size:
{
GST_ELEMENT_ERROR (basepayload, STREAM, FORMAT,
(NULL), ("received AMR frame with size <= 0"));
gst_buffer_unmap (buffer, &map);
gst_buffer_unref (buffer);
return GST_FLOW_ERROR;
}
incomplete_frame:
{
GST_ELEMENT_ERROR (basepayload, STREAM, FORMAT,
(NULL), ("received incomplete AMR frames"));
gst_buffer_unmap (buffer, &map);
gst_buffer_unref (buffer);
return GST_FLOW_ERROR;
}
too_big:
{
GST_ELEMENT_ERROR (basepayload, STREAM, FORMAT,
(NULL), ("received too many AMR frames for MTU"));
gst_buffer_unmap (buffer, &map);
gst_buffer_unref (buffer);
return GST_FLOW_ERROR;
}
}
static GstStateChangeReturn
gst_rtp_amr_pay_change_state (GstElement * element, GstStateChange transition)
{
GstStateChangeReturn ret = GST_STATE_CHANGE_SUCCESS;
/* handle upwards state changes here */
switch (transition) {
default:
break;
}
ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
/* handle downwards state changes */
switch (transition) {
case GST_STATE_CHANGE_PAUSED_TO_READY:
gst_rtp_amr_pay_reset (GST_RTP_AMR_PAY (element));
break;
default:
break;
}
return ret;
}