diff options
Diffstat (limited to 'subprojects/gst-plugins-bad/gst/rist/gstristrtpext.c')
| -rw-r--r-- | subprojects/gst-plugins-bad/gst/rist/gstristrtpext.c | 302 |
1 files changed, 302 insertions, 0 deletions
diff --git a/subprojects/gst-plugins-bad/gst/rist/gstristrtpext.c b/subprojects/gst-plugins-bad/gst/rist/gstristrtpext.c new file mode 100644 index 0000000000..32e3ea177c --- /dev/null +++ b/subprojects/gst-plugins-bad/gst/rist/gstristrtpext.c @@ -0,0 +1,302 @@ +/* GStreamer RIST plugin + * Copyright (C) 2019 Net Insight AB + * Author: Olivier Crete <olivier.crete@collabora.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-ristrtpext + * @title: ristrtpext + * @see_also: ristsink + * + * This elements adds the RTP header extension defined by the RIST profile. + * + * If the GstRistRtpExt::drop-null-ts-packets property is set, then it + * will try to parse a MPEG Transport Stream inside the RTP packets + * and look for "null" packets among the first 7 TS packets and remove + * them, and mark their removal in the header. + * + * If the GstRistRtpExt::sequence-number-extension property is set, it will add + * a RTP sequence number roll-over counter to the RTP header extension. This + * code assumes that packets inserted to this element are never more than half + * of the sequence number space (2^15) away from the latest. Re-transmissions + * should therefore be done after processing with this element. + * + * If the GstRistRtpExt::drop-null-ts-packets and + * GstRistRtpExt::sequence-number-extension properties are both FALSE, it is + * pass through. + */ + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +#include <gst/rtp/rtp.h> + +#include "gstrist.h" + +GST_DEBUG_CATEGORY_STATIC (gst_rist_rtp_ext_debug); +#define GST_CAT_DEFAULT gst_rist_rtp_ext_debug + +enum +{ + PROP_DROP_NULL_TS_PACKETS = 1, + PROP_SEQUENCE_NUMBER_EXTENSION +}; + +static GstStaticPadTemplate src_templ = GST_STATIC_PAD_TEMPLATE ("src", + GST_PAD_SRC, + GST_PAD_ALWAYS, + GST_STATIC_CAPS ("application/x-rtp")); + + +static GstStaticPadTemplate sink_templ = GST_STATIC_PAD_TEMPLATE ("sink", + GST_PAD_SINK, + GST_PAD_ALWAYS, + GST_STATIC_CAPS ("application/x-rtp")); + + +struct _GstRistRtpExt +{ + GstElement parent; + + GstPad *srcpad, *sinkpad; + + gboolean drop_null; + gboolean add_seqnumext; + + guint32 extseqnum; +}; + +G_DEFINE_TYPE_WITH_CODE (GstRistRtpExt, gst_rist_rtp_ext, GST_TYPE_ELEMENT, + GST_DEBUG_CATEGORY_INIT (gst_rist_rtp_ext_debug, "ristrtpext", 0, + "RIST RTP Extension")); +GST_ELEMENT_REGISTER_DEFINE (ristrtpext, "ristrtpext", GST_RANK_NONE, + GST_TYPE_RIST_RTP_EXT); + +static GstFlowReturn +gst_rist_rtp_ext_chain (GstPad * pad, GstObject * parent, GstBuffer * buffer) +{ + GstRistRtpExt *self = GST_RIST_RTP_EXT (parent); + GstRTPBuffer rtp = GST_RTP_BUFFER_INIT; + gboolean drop_null = self->drop_null; + gboolean ts_packet_size = 0; + guint ts_packet_count = 0; + guint8 npd_bits = 0; + gboolean num_packets_deleted = 0; + guint8 *data; + guint wordlen; + + if (!self->drop_null && !self->add_seqnumext) + return gst_pad_push (self->srcpad, buffer); + + if (self->drop_null) { + if (!gst_rtp_buffer_map (buffer, GST_MAP_READ, &rtp)) { + GST_ELEMENT_ERROR (self, STREAM, MUX, (NULL), + ("Could not map RTP buffer")); + goto mapping_error; + } + + if (gst_rtp_buffer_get_payload_type (&rtp) == GST_RTP_PAYLOAD_MP2T) { + if (gst_rtp_buffer_get_payload_len (&rtp) % 188 == 0) { + ts_packet_size = 188; + ts_packet_count = gst_rtp_buffer_get_payload_len (&rtp) / 188; + } else if (gst_rtp_buffer_get_payload_len (&rtp) % 204 == 0) { + ts_packet_size = 204; + ts_packet_count = gst_rtp_buffer_get_payload_len (&rtp) / 204; + } else { + drop_null = FALSE; + } + } + gst_rtp_buffer_unmap (&rtp); + } + + buffer = gst_buffer_make_writable (buffer); + + if (!gst_rtp_buffer_map (buffer, GST_MAP_READWRITE, &rtp)) { + GST_ELEMENT_ERROR (self, STREAM, MUX, (NULL), ("Could not map RTP buffer")); + goto mapping_error; + } + + if (drop_null) { + guint8 *data = gst_rtp_buffer_get_payload (&rtp); + guint plen = gst_rtp_buffer_get_payload_len (&rtp); + guint i; + + if (gst_rtp_buffer_get_padding (&rtp)) { + GST_ELEMENT_ERROR (self, STREAM, MUX, (NULL), + ("FIXME: Can not remove null TS packets if RTP padding is present")); + goto mapping_error; + } + + for (i = 0; i < MIN (ts_packet_count, 7); i++) { + guint offset = (i - num_packets_deleted) * ts_packet_size; + guint16 pid; + + /* Look for sync byte (0x47) at the start of TS packets */ + if (data[offset] != 0x47) { + GST_ELEMENT_ERROR (self, STREAM, MUX, (NULL), + ("Buffer does not contain valid MP2T data," + " the sync byte is not present")); + goto error_mapped; + } + + pid = ((data[offset + 1] & 0x1F) << 8) | data[offset + 2]; + /* is NULL packet (PID == 0x1FFF means null) */ + if (pid == 0x1FFF) { + guint remaining_plen = plen - (num_packets_deleted * ts_packet_size); + + num_packets_deleted++; + npd_bits |= 1 << (6 - i); + if (offset + ts_packet_size < remaining_plen) + memmove (data + offset, data + offset + ts_packet_size, + remaining_plen - offset - ts_packet_size); + } + } + } + + if (gst_rtp_buffer_get_extension (&rtp)) { + GST_ELEMENT_ERROR (self, STREAM, MUX, (NULL), + ("RTP buffer already has an extension set")); + goto error_mapped; + } + + gst_rtp_buffer_set_extension (&rtp, TRUE); + gst_rtp_buffer_set_extension_data (&rtp, 'R' << 8 | 'I', 1); + gst_rtp_buffer_get_extension_data (&rtp, NULL, (void **) &data, &wordlen); + + data[0] = drop_null << 7; + data[0] |= self->add_seqnumext << 6; + if (ts_packet_count <= 7) + data[0] |= (ts_packet_count & 7) << 3; /* Size */ + + data[1] = (ts_packet_size == 204) << 7; + data[1] |= (npd_bits & 0x7F); + + if (self->add_seqnumext) { + guint16 seqnum = gst_rtp_buffer_get_seq (&rtp); + guint32 extseqnum; + + if (GST_BUFFER_IS_DISCONT (buffer)) + self->extseqnum = -1; + + extseqnum = gst_rist_rtp_ext_seq (&self->extseqnum, seqnum); + + GST_WRITE_UINT16_BE (data + 2, (extseqnum >> 16)); + } + + gst_rtp_buffer_unmap (&rtp); + + if (num_packets_deleted != 0) + gst_buffer_resize (buffer, 0, + gst_buffer_get_size (buffer) - (ts_packet_size * num_packets_deleted)); + + return gst_pad_push (self->srcpad, buffer); + +mapping_error: + gst_buffer_unref (buffer); + return GST_FLOW_ERROR; + +error_mapped: + gst_rtp_buffer_unmap (&rtp); + gst_buffer_unref (buffer); + return GST_FLOW_ERROR; +} + +static void +gst_rist_rtp_ext_init (GstRistRtpExt * self) +{ + self->extseqnum = -1; + + self->sinkpad = gst_pad_new_from_static_template (&sink_templ, + sink_templ.name_template); + self->srcpad = gst_pad_new_from_static_template (&src_templ, + src_templ.name_template); + + GST_PAD_SET_PROXY_ALLOCATION (self->sinkpad); + GST_PAD_SET_PROXY_CAPS (self->sinkpad); + gst_pad_set_chain_function (self->sinkpad, gst_rist_rtp_ext_chain); + + gst_element_add_pad (GST_ELEMENT (self), self->sinkpad); + gst_element_add_pad (GST_ELEMENT (self), self->srcpad); +} + +static void +gst_rist_rtp_ext_get_property (GObject * object, guint prop_id, + GValue * value, GParamSpec * pspec) +{ + GstRistRtpExt *self = GST_RIST_RTP_EXT (object); + + switch (prop_id) { + case PROP_DROP_NULL_TS_PACKETS: + g_value_set_boolean (value, self->drop_null); + break; + case PROP_SEQUENCE_NUMBER_EXTENSION: + g_value_set_boolean (value, self->add_seqnumext); + break; + default: + G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); + break; + } +} + +static void +gst_rist_rtp_ext_set_property (GObject * object, guint prop_id, + const GValue * value, GParamSpec * pspec) +{ + GstRistRtpExt *self = GST_RIST_RTP_EXT (object); + + switch (prop_id) { + case PROP_DROP_NULL_TS_PACKETS: + self->drop_null = g_value_get_boolean (value); + break; + case PROP_SEQUENCE_NUMBER_EXTENSION: + self->add_seqnumext = g_value_get_boolean (value); + break; + default: + G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); + break; + } +} + +static void +gst_rist_rtp_ext_class_init (GstRistRtpExtClass * klass) +{ + GstElementClass *element_class = (GstElementClass *) klass; + GObjectClass *object_class = (GObjectClass *) klass; + + gst_element_class_set_metadata (element_class, + "RIST RTP Extension adder", "Filter/Network", + "Adds RIST TR-06-2 RTP Header extension", + "Olivier Crete <olivier.crete@collabora.com"); + gst_element_class_add_static_pad_template (element_class, &src_templ); + gst_element_class_add_static_pad_template (element_class, &sink_templ); + + object_class->get_property = gst_rist_rtp_ext_get_property; + object_class->set_property = gst_rist_rtp_ext_set_property; + + g_object_class_install_property (object_class, PROP_DROP_NULL_TS_PACKETS, + g_param_spec_boolean ("drop-null-ts-packets", "Drop null TS packets", + "Drop null MPEG-TS packet and replace them with a custom header" + " extension.", FALSE, + G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS | G_PARAM_CONSTRUCT)); + g_object_class_install_property (object_class, PROP_SEQUENCE_NUMBER_EXTENSION, + g_param_spec_boolean ("sequence-number-extension", + "Sequence Number Extension", + "Add sequence number extension to packets.", FALSE, + G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS | G_PARAM_CONSTRUCT)); +} |