/* * gstrtpvp8pay.c - Source for GstRtpVP8Pay * Copyright (C) 2011 Sjoerd Simons * Copyright (C) 2011 Collabora Ltd. * Contact: Youness Alaoui * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 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 * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser 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 #include #include #include #include #include #include #include "gstrtpelements.h" #include "gstrtpvp8pay.h" #include "gstrtputils.h" GST_DEBUG_CATEGORY_STATIC (gst_rtp_vp8_pay_debug); #define GST_CAT_DEFAULT gst_rtp_vp8_pay_debug #define DEFAULT_PICTURE_ID_MODE VP8_PAY_NO_PICTURE_ID #define DEFAULT_PICTURE_ID_OFFSET (-1) enum { PROP_0, PROP_PICTURE_ID, PROP_PICTURE_ID_MODE, PROP_PICTURE_ID_OFFSET }; #define GST_TYPE_RTP_VP8_PAY_PICTURE_ID_MODE (gst_rtp_vp8_pay_picture_id_mode_get_type()) static GType gst_rtp_vp8_pay_picture_id_mode_get_type (void) { static GType mode_type = 0; static const GEnumValue modes[] = { {VP8_PAY_NO_PICTURE_ID, "No Picture ID", "none"}, {VP8_PAY_PICTURE_ID_7BITS, "7-bit Picture ID", "7-bit"}, {VP8_PAY_PICTURE_ID_15BITS, "15-bit Picture ID", "15-bit"}, {0, NULL, NULL}, }; if (!mode_type) { mode_type = g_enum_register_static ("GstVP8RTPPayMode", modes); } return mode_type; } static void gst_rtp_vp8_pay_get_property (GObject * object, guint prop_id, GValue * value, GParamSpec * pspec); static void gst_rtp_vp8_pay_set_property (GObject * object, guint prop_id, const GValue * value, GParamSpec * pspec); static GstFlowReturn gst_rtp_vp8_pay_handle_buffer (GstRTPBasePayload * payload, GstBuffer * buffer); static gboolean gst_rtp_vp8_pay_sink_event (GstRTPBasePayload * payload, GstEvent * event); static gboolean gst_rtp_vp8_pay_set_caps (GstRTPBasePayload * payload, GstCaps * caps); G_DEFINE_TYPE (GstRtpVP8Pay, gst_rtp_vp8_pay, GST_TYPE_RTP_BASE_PAYLOAD); GST_ELEMENT_REGISTER_DEFINE_WITH_CODE (rtpvp8pay, "rtpvp8pay", GST_RANK_MARGINAL, GST_TYPE_RTP_VP8_PAY, rtp_element_init (plugin)); static GstStaticPadTemplate gst_rtp_vp8_pay_src_template = GST_STATIC_PAD_TEMPLATE ("src", GST_PAD_SRC, GST_PAD_ALWAYS, GST_STATIC_CAPS ("application/x-rtp, " "payload = (int) " GST_RTP_PAYLOAD_DYNAMIC_STRING "," "clock-rate = (int) 90000, encoding-name = (string) { \"VP8\", \"VP8-DRAFT-IETF-01\" }")); static GstStaticPadTemplate gst_rtp_vp8_pay_sink_template = GST_STATIC_PAD_TEMPLATE ("sink", GST_PAD_SINK, GST_PAD_ALWAYS, GST_STATIC_CAPS ("video/x-vp8")); static gint picture_id_field_len (GstVP8RtpPayPictureIDMode mode) { if (VP8_PAY_NO_PICTURE_ID == mode) return 0; if (VP8_PAY_PICTURE_ID_7BITS == mode) return 7; return 15; } static void gst_rtp_vp8_pay_picture_id_reset (GstRtpVP8Pay * self) { gint nbits; gint old_picture_id = self->picture_id; gint picture_id = 0; if (self->picture_id_mode != VP8_PAY_NO_PICTURE_ID) { if (self->picture_id_offset == -1) { picture_id = g_random_int (); } else { picture_id = self->picture_id_offset; } nbits = picture_id_field_len (self->picture_id_mode); picture_id &= (1 << nbits) - 1; } g_atomic_int_set (&self->picture_id, picture_id); GST_LOG_OBJECT (self, "picture-id reset %d -> %d", old_picture_id, picture_id); } static void gst_rtp_vp8_pay_picture_id_increment (GstRtpVP8Pay * self) { gint nbits; if (self->picture_id_mode == VP8_PAY_NO_PICTURE_ID) return; /* Atomically increment and wrap the picture id if it overflows */ nbits = picture_id_field_len (self->picture_id_mode); gint picture_id = g_atomic_int_get (&self->picture_id); picture_id++; picture_id &= (1 << nbits) - 1; g_atomic_int_set (&self->picture_id, picture_id); } static void gst_rtp_vp8_pay_reset (GstRtpVP8Pay * obj) { gst_rtp_vp8_pay_picture_id_reset (obj); /* tl0picidx MAY start at a random value, but there's no point. Initialize * so that first packet will use 0 for convenience */ obj->tl0picidx = -1; obj->temporal_scalability_fields_present = FALSE; } static void gst_rtp_vp8_pay_init (GstRtpVP8Pay * obj) { obj->picture_id_mode = DEFAULT_PICTURE_ID_MODE; obj->picture_id_offset = DEFAULT_PICTURE_ID_OFFSET; gst_rtp_vp8_pay_reset (obj); } static void gst_rtp_vp8_pay_class_init (GstRtpVP8PayClass * gst_rtp_vp8_pay_class) { GObjectClass *gobject_class = G_OBJECT_CLASS (gst_rtp_vp8_pay_class); GstElementClass *element_class = GST_ELEMENT_CLASS (gst_rtp_vp8_pay_class); GstRTPBasePayloadClass *pay_class = GST_RTP_BASE_PAYLOAD_CLASS (gst_rtp_vp8_pay_class); gobject_class->set_property = gst_rtp_vp8_pay_set_property; gobject_class->get_property = gst_rtp_vp8_pay_get_property; /** * rtpvp8pay:picture-id: * * Currently used picture-id * * Since: 1.24 */ g_object_class_install_property (gobject_class, PROP_PICTURE_ID, g_param_spec_int ("picture-id", "Picture ID", "Currently used picture-id for payloading", 0, 0x7FFF, 0, G_PARAM_READABLE | G_PARAM_STATIC_STRINGS)); g_object_class_install_property (gobject_class, PROP_PICTURE_ID_MODE, g_param_spec_enum ("picture-id-mode", "Picture ID Mode", "The picture ID mode for payloading", GST_TYPE_RTP_VP8_PAY_PICTURE_ID_MODE, DEFAULT_PICTURE_ID_MODE, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)); /** * rtpvp8pay:picture-id-offset: * * Offset to add to the initial picture-id (-1 = random) * * Since: 1.20 */ g_object_class_install_property (gobject_class, PROP_PICTURE_ID_OFFSET, g_param_spec_int ("picture-id-offset", "Picture ID offset", "Offset to add to the initial picture-id (-1 = random)", -1, 0x7FFF, DEFAULT_PICTURE_ID_OFFSET, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)); gst_element_class_add_static_pad_template (element_class, &gst_rtp_vp8_pay_sink_template); gst_element_class_add_static_pad_template (element_class, &gst_rtp_vp8_pay_src_template); gst_element_class_set_static_metadata (element_class, "RTP VP8 payloader", "Codec/Payloader/Network/RTP", "Puts VP8 video in RTP packets", "Sjoerd Simons "); pay_class->handle_buffer = gst_rtp_vp8_pay_handle_buffer; pay_class->sink_event = gst_rtp_vp8_pay_sink_event; pay_class->set_caps = gst_rtp_vp8_pay_set_caps; GST_DEBUG_CATEGORY_INIT (gst_rtp_vp8_pay_debug, "rtpvp8pay", 0, "VP8 Video RTP Payloader"); gst_type_mark_as_plugin_api (GST_TYPE_RTP_VP8_PAY_PICTURE_ID_MODE, 0); } static void gst_rtp_vp8_pay_set_property (GObject * object, guint prop_id, const GValue * value, GParamSpec * pspec) { GstRtpVP8Pay *rtpvp8pay = GST_RTP_VP8_PAY (object); switch (prop_id) { case PROP_PICTURE_ID_MODE: rtpvp8pay->picture_id_mode = g_value_get_enum (value); gst_rtp_vp8_pay_picture_id_reset (rtpvp8pay); break; case PROP_PICTURE_ID_OFFSET: rtpvp8pay->picture_id_offset = g_value_get_int (value); gst_rtp_vp8_pay_picture_id_reset (rtpvp8pay); break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); break; } } static void gst_rtp_vp8_pay_get_property (GObject * object, guint prop_id, GValue * value, GParamSpec * pspec) { GstRtpVP8Pay *rtpvp8pay = GST_RTP_VP8_PAY (object); switch (prop_id) { case PROP_PICTURE_ID: g_value_set_int (value, g_atomic_int_get (&rtpvp8pay->picture_id)); break; case PROP_PICTURE_ID_MODE: g_value_set_enum (value, rtpvp8pay->picture_id_mode); break; case PROP_PICTURE_ID_OFFSET: g_value_set_int (value, rtpvp8pay->picture_id_offset); break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); break; } } static gboolean gst_rtp_vp8_pay_parse_frame (GstRtpVP8Pay * self, GstBuffer * buffer, gsize buffer_size) { GstMapInfo map = GST_MAP_INFO_INIT; GstBitReader reader; guint8 *data; gsize size; int i; gboolean keyframe; guint32 partition0_size; guint8 version; guint8 tmp8 = 0; guint8 partitions; guint offset; guint8 *pdata; if (G_UNLIKELY (buffer_size < 3)) goto error; if (!gst_buffer_map (buffer, &map, GST_MAP_READ) || !map.data) goto error; data = map.data; size = map.size; gst_bit_reader_init (&reader, data, size); self->is_keyframe = keyframe = ((data[0] & 0x1) == 0); version = (data[0] >> 1) & 0x7; if (G_UNLIKELY (version > 3)) { GST_ERROR_OBJECT (self, "Unknown VP8 version %u", version); goto error; } /* keyframe, version and show_frame use 5 bits */ partition0_size = data[2] << 11 | data[1] << 3 | (data[0] >> 5); /* Include the uncompressed data blob in the first partition */ offset = keyframe ? 10 : 3; partition0_size += offset; if (!gst_bit_reader_skip (&reader, 24)) goto error; if (keyframe) { /* check start tag: 0x9d 0x01 0x2a */ if (!gst_bit_reader_get_bits_uint8 (&reader, &tmp8, 8) || tmp8 != 0x9d) goto error; if (!gst_bit_reader_get_bits_uint8 (&reader, &tmp8, 8) || tmp8 != 0x01) goto error; if (!gst_bit_reader_get_bits_uint8 (&reader, &tmp8, 8) || tmp8 != 0x2a) goto error; /* Skip horizontal size code (16 bits) vertical size code (16 bits) */ if (!gst_bit_reader_skip (&reader, 32)) goto error; } offset = keyframe ? 10 : 3; /* Everything below is actually using some form of arithmetic coding, but as * all the bits we're interested in are encoded with 50:50 probability * they're written out as they are and we can just continue using the bit * reader here */ if (keyframe) { /* color space (1 bit) and clamping type (1 bit) */ if (!gst_bit_reader_skip (&reader, 2)) goto error; } /* segmentation_enabled */ if (!gst_bit_reader_get_bits_uint8 (&reader, &tmp8, 1)) goto error; if (tmp8) { guint8 update_mb_segmentation_map; guint8 update_segment_feature_data; if (!gst_bit_reader_get_bits_uint8 (&reader, &update_mb_segmentation_map, 1)) goto error; if (!gst_bit_reader_get_bits_uint8 (&reader, &update_segment_feature_data, 1)) goto error; if (update_segment_feature_data) { /* skip segment feature mode */ if (!gst_bit_reader_skip (&reader, 1)) goto error; /* quantizer update */ for (i = 0; i < 4; i++) { /* skip flagged quantizer value (7 bits) and sign (1 bit) */ if (!gst_bit_reader_get_bits_uint8 (&reader, &tmp8, 1)) goto error; if (tmp8) if (!gst_bit_reader_skip (&reader, 8)) goto error; } /* loop filter update */ for (i = 0; i < 4; i++) { /* skip flagged lf update value (6 bits) and sign (1 bit) */ if (!gst_bit_reader_get_bits_uint8 (&reader, &tmp8, 1)) goto error; if (tmp8) if (!gst_bit_reader_skip (&reader, 7)) goto error; } } if (update_mb_segmentation_map) { /* segment prob update */ for (i = 0; i < 3; i++) { /* skip flagged segment prob */ if (!gst_bit_reader_get_bits_uint8 (&reader, &tmp8, 1)) goto error; if (!gst_bit_reader_skip (&reader, 8)) goto error; } } } /* skip filter type (1 bit), loop filter level (6 bits) and * sharpness level (3 bits) */ if (!gst_bit_reader_skip (&reader, 1 + 6 + 3)) goto error; /* loop_filter_adj_enabled */ if (!gst_bit_reader_get_bits_uint8 (&reader, &tmp8, 1)) goto error; if (tmp8) { /* delta update */ if (!gst_bit_reader_get_bits_uint8 (&reader, &tmp8, 1)) goto error; if (tmp8) { for (i = 0; i < 8; i++) { /* 8 updates, 1 bit indicate whether there is one and if follow by a * 7 bit update */ if (!gst_bit_reader_get_bits_uint8 (&reader, &tmp8, 1)) goto error; if (tmp8) if (!gst_bit_reader_skip (&reader, 7)) goto error; } } } if (!gst_bit_reader_get_bits_uint8 (&reader, &tmp8, 2)) goto error; partitions = 1 << tmp8; /* Check if things are still sensible */ if (partition0_size + (partitions - 1) * 3 >= size) goto error; /* partition data is right after the mode partition */ pdata = data + partition0_size; /* Set up mapping */ self->n_partitions = partitions + 1; self->partition_offset[0] = 0; self->partition_size[0] = partition0_size + (partitions - 1) * 3; self->partition_offset[1] = self->partition_size[0]; for (i = 1; i < partitions; i++) { guint psize = (pdata[2] << 16 | pdata[1] << 8 | pdata[0]); pdata += 3; self->partition_size[i] = psize; self->partition_offset[i + 1] = self->partition_offset[i] + psize; } /* Check that our partition offsets and sizes don't go outsize the buffer * size. */ if (self->partition_offset[i] >= size) goto error; self->partition_size[i] = size - self->partition_offset[i]; self->partition_offset[i + 1] = size; gst_buffer_unmap (buffer, &map); if (keyframe) GST_DEBUG_OBJECT (self, "Parsed keyframe"); return TRUE; error: GST_DEBUG ("Failed to parse frame"); if (map.memory != NULL) { gst_buffer_unmap (buffer, &map); } return FALSE; } static guint gst_rtp_vp8_offset_to_partition (GstRtpVP8Pay * self, guint offset) { int i; for (i = 1; i < self->n_partitions; i++) { if (offset < self->partition_offset[i]) return i - 1; } return i - 1; } static gsize gst_rtp_vp8_calc_header_len (GstRtpVP8Pay * self) { gsize len; switch (self->picture_id_mode) { case VP8_PAY_PICTURE_ID_7BITS: len = 1; break; case VP8_PAY_PICTURE_ID_15BITS: len = 2; break; case VP8_PAY_NO_PICTURE_ID: default: len = 0; break; } if (self->temporal_scalability_fields_present) { /* Add on space for TL0PICIDX and TID/Y/KEYIDX */ len += 2; } if (len > 0) { /* All fields above are extension, so allocate space for the ECB field */ len++; } return len + 1; /* computed + fixed size header */ } /* When growing the vp8 header keep max payload len calculation in sync */ static GstBuffer * gst_rtp_vp8_create_header_buffer (GstRtpVP8Pay * self, guint8 partid, gboolean start, gboolean mark, GstBuffer * in, GstCustomMeta * meta) { GstBuffer *out; guint8 *p; GstRTPBuffer rtpbuffer = GST_RTP_BUFFER_INIT; out = gst_rtp_base_payload_allocate_output_buffer (GST_RTP_BASE_PAYLOAD_CAST (self), gst_rtp_vp8_calc_header_len (self), 0, 0); gst_rtp_buffer_map (out, GST_MAP_READWRITE, &rtpbuffer); p = gst_rtp_buffer_get_payload (&rtpbuffer); /* X=0,R=0,N=0,S=start,PartID=partid */ p[0] = (start << 4) | partid; if (GST_BUFFER_FLAG_IS_SET (in, GST_BUFFER_FLAG_DROPPABLE)) { /* Enable N=1 */ p[0] |= 0x20; } if (self->picture_id_mode != VP8_PAY_NO_PICTURE_ID || self->temporal_scalability_fields_present) { gint index; /* Enable X=1 */ p[0] |= 0x80; /* X: I=0,L=0,T=0,K=0,RSV=0 */ p[1] = 0x00; if (self->picture_id_mode != VP8_PAY_NO_PICTURE_ID) { /* Set I bit */ p[1] |= 0x80; } if (self->temporal_scalability_fields_present) { /* Set L and T bits */ p[1] |= 0x60; } /* Insert picture ID */ if (self->picture_id_mode == VP8_PAY_PICTURE_ID_7BITS) { /* I: 7 bit picture_id */ p[2] = self->picture_id & 0x7F; index = 3; } else if (self->picture_id_mode == VP8_PAY_PICTURE_ID_15BITS) { /* I: 15 bit picture_id */ p[2] = 0x80 | ((self->picture_id & 0x7FFF) >> 8); p[3] = self->picture_id & 0xFF; index = 4; } else { index = 2; } /* Insert TL0PICIDX and TID/Y/KEYIDX */ if (self->temporal_scalability_fields_present) { /* The meta contains tl0picidx from the encoder, but we need to ensure * that tl0picidx is increasing correctly. The encoder may reset it's * state and counter, but we cannot. Therefore, we cannot simply copy * the value into the header.*/ guint temporal_layer = 0; gboolean layer_sync = FALSE; gboolean use_temporal_scaling = FALSE; if (meta) { gst_structure_get_boolean (meta->structure, "use-temporal-scaling", &use_temporal_scaling); if (use_temporal_scaling) gst_structure_get (meta->structure, "layer-id", G_TYPE_UINT, &temporal_layer, "layer-sync", G_TYPE_BOOLEAN, &layer_sync, NULL); } /* FIXME: Support a prediction structure where higher layers don't * necessarily refer to the last base layer frame, ie they use an older * tl0picidx as signalled in the meta */ if (temporal_layer == 0 && start) self->tl0picidx++; p[index] = self->tl0picidx & 0xFF; p[index + 1] = ((temporal_layer << 6) | (layer_sync << 5)) & 0xFF; } } gst_rtp_buffer_set_marker (&rtpbuffer, mark); if (mark) GST_BUFFER_FLAG_SET (out, GST_BUFFER_FLAG_MARKER); gst_rtp_buffer_unmap (&rtpbuffer); GST_BUFFER_DURATION (out) = GST_BUFFER_DURATION (in); GST_BUFFER_PTS (out) = GST_BUFFER_PTS (in); return out; } static gboolean foreach_metadata_drop (GstBuffer * buf, GstMeta ** meta, gpointer user_data) { GstElement *element = user_data; const GstMetaInfo *info = (*meta)->info; if (gst_meta_info_is_custom (info) && gst_custom_meta_has_name ((GstCustomMeta *) * meta, "GstVP8Meta")) { GST_DEBUG_OBJECT (element, "dropping GstVP8Meta"); *meta = NULL; } return TRUE; } static void gst_rtp_vp8_drop_vp8_meta (gpointer element, GstBuffer * buf) { gst_buffer_foreach_meta (buf, foreach_metadata_drop, element); } static guint gst_rtp_vp8_payload_next (GstRtpVP8Pay * self, GstBufferList * list, guint offset, GstBuffer * buffer, gsize buffer_size, gsize max_payload_len, GstCustomMeta * meta, gboolean delta_unit) { guint partition; GstBuffer *header; GstBuffer *sub; GstBuffer *out; gboolean mark; gboolean start; gsize remaining; gsize available; remaining = buffer_size - offset; available = max_payload_len; if (available > remaining) available = remaining; if (self->temporal_scalability_fields_present && meta) { /* If meta is present, then we have no partition offset information, * so always emit PID 0 and set the start bit for the first packet * of a frame only (c.f. RFC7741 $4.4) */ partition = 0; start = (offset == 0); } else { partition = gst_rtp_vp8_offset_to_partition (self, offset); g_assert (partition < self->n_partitions); start = (offset == self->partition_offset[partition]); } mark = (remaining == available); /* whole set of partitions, payload them and done */ header = gst_rtp_vp8_create_header_buffer (self, partition, start, mark, buffer, meta); sub = gst_buffer_copy_region (buffer, GST_BUFFER_COPY_ALL, offset, available); gst_rtp_copy_video_meta (self, header, buffer); gst_rtp_vp8_drop_vp8_meta (self, header); out = gst_buffer_append (header, sub); if (delta_unit) GST_BUFFER_FLAG_SET (out, GST_BUFFER_FLAG_DELTA_UNIT); gst_buffer_list_insert (list, -1, out); return available; } static GstFlowReturn gst_rtp_vp8_pay_handle_buffer (GstRTPBasePayload * payload, GstBuffer * buffer) { GstRtpVP8Pay *self = GST_RTP_VP8_PAY (payload); GstFlowReturn ret; GstBufferList *list; GstCustomMeta *meta; gsize size, max_paylen; guint offset, mtu, vp8_hdr_len; gboolean delta_unit; size = gst_buffer_get_size (buffer); meta = gst_buffer_get_custom_meta (buffer, "GstVP8Meta"); delta_unit = GST_BUFFER_FLAG_IS_SET (buffer, GST_BUFFER_FLAG_DELTA_UNIT); if (G_UNLIKELY (!gst_rtp_vp8_pay_parse_frame (self, buffer, size))) { GST_ELEMENT_ERROR (self, STREAM, ENCODE, (NULL), ("Failed to parse VP8 frame")); return GST_FLOW_ERROR; } if (meta) { gboolean use_temporal_scaling; /* For interop it's most likely better to keep the temporal scalability * fields present if the stream previously had them present. Alternating * whether these fields are present or not may confuse the receiver. */ gst_structure_get_boolean (meta->structure, "use-temporal-scaling", &use_temporal_scaling); if (use_temporal_scaling) self->temporal_scalability_fields_present = TRUE; } mtu = GST_RTP_BASE_PAYLOAD_MTU (payload); vp8_hdr_len = gst_rtp_vp8_calc_header_len (self); max_paylen = gst_rtp_buffer_calc_payload_len (mtu - vp8_hdr_len, 0, gst_rtp_base_payload_get_source_count (payload, buffer)); list = gst_buffer_list_new_sized ((size / max_paylen) + 1); offset = 0; while (offset < size) { offset += gst_rtp_vp8_payload_next (self, list, offset, buffer, size, max_paylen, meta, delta_unit); /* only the first outgoing packet should not have the DELTA_UNIT flag */ if (!delta_unit) delta_unit = TRUE; } ret = gst_rtp_base_payload_push_list (payload, list); gst_rtp_vp8_pay_picture_id_increment (self); gst_buffer_unref (buffer); return ret; } static gboolean gst_rtp_vp8_pay_sink_event (GstRTPBasePayload * payload, GstEvent * event) { GstRtpVP8Pay *self = GST_RTP_VP8_PAY (payload); GstEventType event_type = GST_EVENT_TYPE (event); if (event_type == GST_EVENT_GAP || event_type == GST_EVENT_FLUSH_START) { gint picture_id = self->picture_id; gst_rtp_vp8_pay_picture_id_increment (self); GST_DEBUG_OBJECT (payload, "Incrementing picture ID on %s event %d -> %d", GST_EVENT_TYPE_NAME (event), picture_id, self->picture_id); } return GST_RTP_BASE_PAYLOAD_CLASS (gst_rtp_vp8_pay_parent_class)->sink_event (payload, event); } static gboolean gst_rtp_vp8_pay_set_caps (GstRTPBasePayload * payload, GstCaps * caps) { GstCaps *src_caps; const char *encoding_name = "VP8"; src_caps = gst_pad_get_allowed_caps (GST_RTP_BASE_PAYLOAD_SRCPAD (payload)); if (src_caps) { GstStructure *s; const GValue *value; s = gst_caps_get_structure (src_caps, 0); if (gst_structure_has_field (s, "encoding-name")) { GValue default_value = G_VALUE_INIT; g_value_init (&default_value, G_TYPE_STRING); g_value_set_static_string (&default_value, encoding_name); value = gst_structure_get_value (s, "encoding-name"); if (!gst_value_can_intersect (&default_value, value)) encoding_name = "VP8-DRAFT-IETF-01"; } gst_caps_unref (src_caps); } gst_rtp_base_payload_set_options (payload, "video", TRUE, encoding_name, 90000); return gst_rtp_base_payload_set_outcaps (payload, NULL); }