2 * Copyright (C) 2006 Marcel Moreaux <marcelm@spacelabs.nl>
3 * (C) 2008 Wim Taymans <wim.taymans@gmail.com>
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Library General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Library General Public License for more details.
15 * You should have received a copy of the GNU Library General Public
16 * License along with this library; if not, write to the
17 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
18 * Boston, MA 02110-1301, USA.
24 * Important note for NTSC-users:
26 * Because the author uses PAL video, and he does not have proper DV
27 * documentation (the DV format specification is not freely available),
28 * this code may very well contain PAL-specific assumptions.
35 #include "gstrtpdvdepay.h"
37 GST_DEBUG_CATEGORY (rtpdvdepay_debug);
38 #define GST_CAT_DEFAULT (rtpdvdepay_debug)
39 /* Filter signals and args */
51 static GstStaticPadTemplate src_factory = GST_STATIC_PAD_TEMPLATE ("src",
54 GST_STATIC_CAPS ("video/x-dv")
57 static GstStaticPadTemplate sink_factory = GST_STATIC_PAD_TEMPLATE ("sink",
60 GST_STATIC_CAPS ("application/x-rtp, "
61 "media = (string) { \"video\", \"audio\" },"
62 "encoding-name = (string) \"DV\", "
63 "clock-rate = (int) 90000,"
64 "encode = (string) { \"SD-VCR/525-60\", \"SD-VCR/625-50\", \"HD-VCR/1125-60\","
65 "\"HD-VCR/1250-50\", \"SDL-VCR/525-60\", \"SDL-VCR/625-50\","
66 "\"306M/525-60\", \"306M/625-50\", \"314M-25/525-60\","
67 "\"314M-25/625-50\", \"314M-50/525-60\", \"314M-50/625-50\" }"
68 /* optional parameters can't go in the template
69 * "audio = (string) { \"bundled\", \"none\" }"
74 static GstStateChangeReturn
75 gst_rtp_dv_depay_change_state (GstElement * element, GstStateChange transition);
77 static GstBuffer *gst_rtp_dv_depay_process (GstRTPBaseDepayload * base,
79 static gboolean gst_rtp_dv_depay_setcaps (GstRTPBaseDepayload * depayload,
82 #define gst_rtp_dv_depay_parent_class parent_class
83 G_DEFINE_TYPE (GstRTPDVDepay, gst_rtp_dv_depay, GST_TYPE_RTP_BASE_DEPAYLOAD);
87 gst_rtp_dv_depay_class_init (GstRTPDVDepayClass * klass)
89 GstElementClass *gstelement_class = (GstElementClass *) klass;
90 GstRTPBaseDepayloadClass *gstrtpbasedepayload_class =
91 (GstRTPBaseDepayloadClass *) klass;
93 GST_DEBUG_CATEGORY_INIT (rtpdvdepay_debug, "rtpdvdepay", 0,
94 "DV RTP Depayloader");
96 gstelement_class->change_state =
97 GST_DEBUG_FUNCPTR (gst_rtp_dv_depay_change_state);
99 gst_element_class_add_pad_template (gstelement_class,
100 gst_static_pad_template_get (&src_factory));
101 gst_element_class_add_pad_template (gstelement_class,
102 gst_static_pad_template_get (&sink_factory));
104 gst_element_class_set_static_metadata (gstelement_class, "RTP DV Depayloader",
105 "Codec/Depayloader/Network/RTP",
106 "Depayloads DV from RTP packets (RFC 3189)",
107 "Marcel Moreaux <marcelm@spacelabs.nl>, Wim Taymans <wim.taymans@gmail.com>");
109 gstrtpbasedepayload_class->process =
110 GST_DEBUG_FUNCPTR (gst_rtp_dv_depay_process);
111 gstrtpbasedepayload_class->set_caps =
112 GST_DEBUG_FUNCPTR (gst_rtp_dv_depay_setcaps);
115 /* initialize the new element
116 * instantiate pads and add them to element
118 * initialize structure
121 gst_rtp_dv_depay_init (GstRTPDVDepay * filter)
126 parse_encode (GstRTPDVDepay * rtpdvdepay, const gchar * encode)
128 rtpdvdepay->width = 720;
129 if (!strcmp (encode, "314M-25/525-60")) {
130 rtpdvdepay->frame_size = 240000;
131 rtpdvdepay->height = 480;
132 rtpdvdepay->rate_num = 30000;
133 rtpdvdepay->rate_denom = 1001;
134 } else if (!strcmp (encode, "SD-VCR/525-60")) {
135 rtpdvdepay->frame_size = 120000;
136 rtpdvdepay->height = 480;
137 rtpdvdepay->rate_num = 30000;
138 rtpdvdepay->rate_denom = 1001;
139 } else if (!strcmp (encode, "314M-50/625-50")) {
140 rtpdvdepay->frame_size = 288000;
141 rtpdvdepay->height = 576;
142 rtpdvdepay->rate_num = 25;
143 rtpdvdepay->rate_denom = 1;
144 } else if (!strcmp (encode, "SD-VCR/625-50")) {
145 rtpdvdepay->frame_size = 144000;
146 rtpdvdepay->height = 576;
147 rtpdvdepay->rate_num = 25;
148 rtpdvdepay->rate_denom = 1;
149 } else if (!strcmp (encode, "314M-25/625-50")) {
150 rtpdvdepay->frame_size = 144000;
151 rtpdvdepay->height = 576;
152 rtpdvdepay->rate_num = 25;
153 rtpdvdepay->rate_denom = 1;
155 rtpdvdepay->frame_size = -1;
157 return rtpdvdepay->frame_size != -1;
161 gst_rtp_dv_depay_setcaps (GstRTPBaseDepayload * depayload, GstCaps * caps)
163 GstStructure *structure;
164 GstRTPDVDepay *rtpdvdepay;
167 gboolean systemstream, ret;
168 const gchar *encode, *media;
170 rtpdvdepay = GST_RTP_DV_DEPAY (depayload);
172 structure = gst_caps_get_structure (caps, 0);
174 if (!gst_structure_get_int (structure, "clock-rate", &clock_rate))
175 clock_rate = 90000; /* default */
176 depayload->clock_rate = clock_rate;
178 /* we really need the encode property to figure out the frame size, it's also
179 * required by the spec */
180 if (!(encode = gst_structure_get_string (structure, "encode")))
183 /* figure out the size of one frame */
184 if (!parse_encode (rtpdvdepay, encode))
187 /* check the media, this tells us that the stream has video or not */
188 if (!(media = gst_structure_get_string (structure, "media")))
191 systemstream = FALSE;
193 if (!strcmp (media, "audio")) {
194 /* we need a demuxer for audio only */
196 } else if (!strcmp (media, "video")) {
199 /* check the optional audio field, if it's present and set to bundled, we
200 * are dealing with a system stream. */
201 if ((audio = gst_structure_get_string (structure, "audio"))) {
202 if (!strcmp (audio, "bundled"))
207 /* allocate accumulator */
208 rtpdvdepay->acc = gst_buffer_new_and_alloc (rtpdvdepay->frame_size);
210 /* Initialize the new accumulator frame.
211 * If the previous frame exists, copy that into the accumulator frame.
212 * This way, missing packets in the stream won't show up badly. */
213 gst_buffer_memset (rtpdvdepay->acc, 0, 0, rtpdvdepay->frame_size);
215 srccaps = gst_caps_new_simple ("video/x-dv",
216 "systemstream", G_TYPE_BOOLEAN, systemstream,
217 "width", G_TYPE_INT, rtpdvdepay->width,
218 "height", G_TYPE_INT, rtpdvdepay->height,
219 "framerate", GST_TYPE_FRACTION, rtpdvdepay->rate_num,
220 rtpdvdepay->rate_denom, NULL);
221 ret = gst_pad_set_caps (depayload->srcpad, srccaps);
222 gst_caps_unref (srccaps);
229 GST_ERROR_OBJECT (rtpdvdepay, "required encode property not found in caps");
234 GST_ERROR_OBJECT (rtpdvdepay, "unknown encode property %s found", encode);
239 GST_ERROR_OBJECT (rtpdvdepay, "required media property not found in caps");
244 /* A DV frame consists of a bunch of 80-byte DIF blocks.
245 * Each DIF block contains a 3-byte header telling where in the DV frame the
246 * DIF block should go. We use this information to calculate its position.
249 calculate_difblock_location (guint8 * block)
251 gint block_type, dif_sequence, dif_block;
254 block_type = block[0] >> 5;
255 dif_sequence = block[1] >> 4;
256 dif_block = block[2];
258 location = dif_sequence * 150;
260 switch (block_type) {
261 case 0: /* Header block, no offset */
263 case 1: /* Subcode block */
264 location += (1 + dif_block);
266 case 2: /* VAUX block */
267 location += (3 + dif_block);
269 case 3: /* Audio block */
270 location += (6 + dif_block * 16);
272 case 4: /* Video block */
273 location += (7 + (dif_block / 15) + dif_block);
275 default: /* Something bogus */
276 GST_DEBUG ("UNKNOWN BLOCK");
283 /* Process one RTP packet. Accumulate RTP payload in the proper place in a DV
284 * frame, and return that frame if we detect a new frame, or NULL otherwise.
285 * We assume a DV frame is 144000 bytes. That should accomodate PAL as well as
289 gst_rtp_dv_depay_process (GstRTPBaseDepayload * base, GstBuffer * in)
291 GstBuffer *out = NULL;
294 guint payload_len, location;
295 GstRTPDVDepay *dvdepay = GST_RTP_DV_DEPAY (base);
297 GstRTPBuffer rtp = { NULL, };
299 gst_rtp_buffer_map (in, GST_MAP_READ, &rtp);
301 marker = gst_rtp_buffer_get_marker (&rtp);
303 /* Check if the received packet contains (the start of) a new frame, we do
304 * this by checking the RTP timestamp. */
305 rtp_ts = gst_rtp_buffer_get_timestamp (&rtp);
307 /* we cannot copy the packet yet if the marker is set, we will do that below
308 * after taking out the data */
309 if (dvdepay->prev_ts != -1 && rtp_ts != dvdepay->prev_ts && !marker) {
310 /* the timestamp changed */
311 GST_DEBUG_OBJECT (dvdepay, "new frame with ts %u, old ts %u", rtp_ts,
314 /* return copy of accumulator. */
315 out = gst_buffer_copy (dvdepay->acc);
318 /* Extract the payload */
319 payload_len = gst_rtp_buffer_get_payload_len (&rtp);
320 payload = gst_rtp_buffer_get_payload (&rtp);
322 /* copy all DIF chunks in their place. */
323 while (payload_len >= 80) {
326 /* Calculate where in the frame the payload should go */
327 location = calculate_difblock_location (payload);
330 /* part of a header, set the flag to mark that we have the header. */
331 dvdepay->header_mask |= (1 << location);
332 GST_LOG_OBJECT (dvdepay, "got header at location %d, now %02x", location,
333 dvdepay->header_mask);
335 GST_LOG_OBJECT (dvdepay, "got block at location %d", location);
338 if (location != -1) {
339 /* get the byte offset of the dif block */
340 offset = location * 80;
342 /* And copy it in, provided the location is sane. */
343 if (offset <= dvdepay->frame_size - 80)
344 gst_buffer_fill (dvdepay->acc, offset, payload, 80);
350 gst_rtp_buffer_unmap (&rtp);
353 GST_DEBUG_OBJECT (dvdepay, "marker bit complete frame %u", rtp_ts);
354 /* only copy the frame when we have a complete header */
355 if (dvdepay->header_mask == 0x3f) {
356 /* The marker marks the end of a frame that we need to push. The next frame
357 * will change the timestamp but we won't copy the accumulator again because
358 * we set the prev_ts to -1. */
359 out = gst_buffer_copy (dvdepay->acc);
361 GST_WARNING_OBJECT (dvdepay, "waiting for frame headers %02x",
362 dvdepay->header_mask);
364 dvdepay->prev_ts = -1;
366 /* save last timestamp */
367 dvdepay->prev_ts = rtp_ts;
373 gst_rtp_dv_depay_reset (GstRTPDVDepay * depay)
376 gst_buffer_unref (depay->acc);
380 depay->header_mask = 0;
383 static GstStateChangeReturn
384 gst_rtp_dv_depay_change_state (GstElement * element, GstStateChange transition)
386 GstStateChangeReturn ret;
387 GstRTPDVDepay *depay = GST_RTP_DV_DEPAY (element);
389 switch (transition) {
390 case GST_STATE_CHANGE_READY_TO_PAUSED:
391 gst_rtp_dv_depay_reset (depay);
397 ret = GST_CALL_PARENT_WITH_DEFAULT (GST_ELEMENT_CLASS, change_state,
398 (element, transition), GST_STATE_CHANGE_FAILURE);
400 switch (transition) {
401 case GST_STATE_CHANGE_PAUSED_TO_READY:
402 gst_rtp_dv_depay_reset (depay);
411 gst_rtp_dv_depay_plugin_init (GstPlugin * plugin)
413 return gst_element_register (plugin, "rtpdvdepay",
414 GST_RANK_SECONDARY, GST_TYPE_RTP_DV_DEPAY);