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., 59 Temple Place - Suite 330,
18 * Boston, MA 02111-1307, 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 "payload = (int) " GST_RTP_PAYLOAD_DYNAMIC_STRING ", "
63 "encoding-name = (string) \"DV\", "
64 "clock-rate = (int) 90000,"
65 "encode = (string) { \"SD-VCR/525-60\", \"SD-VCR/625-50\", \"HD-VCR/1125-60\","
66 "\"HD-VCR/1250-50\", \"SDL-VCR/525-60\", \"SDL-VCR/625-50\","
67 "\"306M/525-60\", \"306M/625-50\", \"314M-25/525-60\","
68 "\"314M-25/625-50\", \"314M-50/525-60\", \"314M-50/625-50\" }"
69 /* optional parameters can't go in the template
70 * "audio = (string) { \"bundled\", \"none\" }"
75 static GstStateChangeReturn
76 gst_rtp_dv_depay_change_state (GstElement * element, GstStateChange transition);
78 static GstBuffer *gst_rtp_dv_depay_process (GstBaseRTPDepayload * base,
80 static gboolean gst_rtp_dv_depay_setcaps (GstBaseRTPDepayload * depayload,
83 GST_BOILERPLATE (GstRTPDVDepay, gst_rtp_dv_depay, GstBaseRTPDepayload,
84 GST_TYPE_BASE_RTP_DEPAYLOAD)
86 static void gst_rtp_dv_depay_base_init (gpointer g_class)
88 static GstElementDetails plugin_details = {
90 "Codec/Depayloader/Network",
91 "Depayloads DV from RTP packets (RFC 3189)",
92 "Marcel Moreaux <marcelm@spacelabs.nl>, Wim Taymans <wim.taymans@gmail.com>"
94 GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);
96 gst_element_class_add_pad_template (element_class,
97 gst_static_pad_template_get (&src_factory));
98 gst_element_class_add_pad_template (element_class,
99 gst_static_pad_template_get (&sink_factory));
101 gst_element_class_set_details (element_class, &plugin_details);
104 /* initialize the plugin's class */
106 gst_rtp_dv_depay_class_init (GstRTPDVDepayClass * klass)
108 GstElementClass *gstelement_class = (GstElementClass *) klass;
109 GstBaseRTPDepayloadClass *gstbasertpdepayload_class =
110 (GstBaseRTPDepayloadClass *) klass;
112 gstelement_class->change_state =
113 GST_DEBUG_FUNCPTR (gst_rtp_dv_depay_change_state);
115 gstbasertpdepayload_class->process =
116 GST_DEBUG_FUNCPTR (gst_rtp_dv_depay_process);
117 gstbasertpdepayload_class->set_caps =
118 GST_DEBUG_FUNCPTR (gst_rtp_dv_depay_setcaps);
120 GST_DEBUG_CATEGORY_INIT (rtpdvdepay_debug, "rtpdvdepay", 0,
121 "DV RTP Depayloader");
124 /* initialize the new element
125 * instantiate pads and add them to element
127 * initialize structure
130 gst_rtp_dv_depay_init (GstRTPDVDepay * filter, GstRTPDVDepayClass * klass)
135 parse_encode (GstRTPDVDepay * rtpdvdepay, const gchar * encode)
137 rtpdvdepay->width = 720;
138 if (!strcmp (encode, "314M-25/525-60")) {
139 rtpdvdepay->frame_size = 240000;
140 rtpdvdepay->height = 480;
141 rtpdvdepay->rate_num = 30000;
142 rtpdvdepay->rate_denom = 1001;
143 } else if (!strcmp (encode, "SD-VCR/525-60")) {
144 rtpdvdepay->frame_size = 120000;
145 rtpdvdepay->height = 480;
146 rtpdvdepay->rate_num = 30000;
147 rtpdvdepay->rate_denom = 1001;
148 } else if (!strcmp (encode, "314M-50/625-50")) {
149 rtpdvdepay->frame_size = 288000;
150 rtpdvdepay->height = 576;
151 rtpdvdepay->rate_num = 25;
152 rtpdvdepay->rate_denom = 1;
153 } else if (!strcmp (encode, "SD-VCR/625-50")) {
154 rtpdvdepay->frame_size = 144000;
155 rtpdvdepay->height = 576;
156 rtpdvdepay->rate_num = 25;
157 rtpdvdepay->rate_denom = 1;
158 } else if (!strcmp (encode, "314M-25/625-50")) {
159 rtpdvdepay->frame_size = 144000;
160 rtpdvdepay->height = 576;
161 rtpdvdepay->rate_num = 25;
162 rtpdvdepay->rate_denom = 1;
164 rtpdvdepay->frame_size = -1;
166 return rtpdvdepay->frame_size != -1;
170 gst_rtp_dv_depay_setcaps (GstBaseRTPDepayload * depayload, GstCaps * caps)
172 GstStructure *structure;
173 GstRTPDVDepay *rtpdvdepay;
176 gboolean systemstream, ret;
177 const gchar *encode, *media;
179 rtpdvdepay = GST_RTP_DV_DEPAY (depayload);
181 structure = gst_caps_get_structure (caps, 0);
183 if (!gst_structure_get_int (structure, "clock-rate", &clock_rate))
184 clock_rate = 90000; /* default */
185 depayload->clock_rate = clock_rate;
187 /* we really need the encode property to figure out the frame size, it's also
188 * required by the spec */
189 if (!(encode = gst_structure_get_string (structure, "encode")))
192 /* figure out the size of one frame */
193 if (!parse_encode (rtpdvdepay, encode))
196 /* check the media, this tells us that the stream has video or not */
197 if (!(media = gst_structure_get_string (structure, "media")))
200 systemstream = FALSE;
202 if (!strcmp (media, "audio")) {
203 /* we need a demuxer for audio only */
205 } else if (!strcmp (media, "video")) {
208 /* check the optional audio field, if it's present and set to bundled, we
209 * are dealing with a system stream. */
210 if ((audio = gst_structure_get_string (structure, "audio"))) {
211 if (!strcmp (audio, "bundled"))
216 /* allocate accumulator */
217 rtpdvdepay->acc = gst_buffer_new_and_alloc (rtpdvdepay->frame_size);
219 /* Initialize the new accumulator frame.
220 * If the previous frame exists, copy that into the accumulator frame.
221 * This way, missing packets in the stream won't show up badly. */
222 memset (GST_BUFFER_DATA (rtpdvdepay->acc), 0, rtpdvdepay->frame_size);
224 srccaps = gst_caps_new_simple ("video/x-dv",
225 "systemstream", G_TYPE_BOOLEAN, systemstream,
226 "width", G_TYPE_INT, rtpdvdepay->width,
227 "height", G_TYPE_INT, rtpdvdepay->height,
228 "framerate", GST_TYPE_FRACTION, rtpdvdepay->rate_num,
229 rtpdvdepay->rate_denom, NULL);
230 ret = gst_pad_set_caps (depayload->srcpad, srccaps);
231 gst_caps_unref (srccaps);
238 GST_ERROR_OBJECT (rtpdvdepay, "required encode property not found in caps");
243 GST_ERROR_OBJECT (rtpdvdepay, "unknown encode property %s found", encode);
248 GST_ERROR_OBJECT (rtpdvdepay, "required media property not found in caps");
253 /* A DV frame consists of a bunch of 80-byte DIF blocks.
254 * Each DIF block contains a 3-byte header telling where in the DV frame the
255 * DIF block should go. We use this information to calculate its position.
258 calculate_difblock_location (guint8 * block)
260 gint block_type, dif_sequence, dif_block;
263 block_type = block[0] >> 5;
264 dif_sequence = block[1] >> 4;
265 dif_block = block[2];
267 switch (block_type) {
268 case 0: /* Header block */
269 location = dif_sequence * 150 * 80;
271 case 1: /* Subcode block */
272 location = dif_sequence * 150 * 80 + (1 + dif_block) * 80;
274 case 2: /* VAUX block */
275 location = dif_sequence * 150 * 80 + (3 + dif_block) * 80;
277 case 3: /* Audio block */
278 location = dif_sequence * 150 * 80 + (6 + dif_block * 16) * 80;
280 case 4: /* Video block */
281 location = dif_sequence * 150 * 80 +
282 (7 + (dif_block / 15) + dif_block) * 80;
284 default: /* Something bogus */
285 GST_DEBUG ("UNKNOWN BLOCK");
292 /* Process one RTP packet. Accumulate RTP payload in the proper place in a DV
293 * frame, and return that frame if we detect a new frame, or NULL otherwise.
294 * We assume a DV frame is 144000 bytes. That should accomodate PAL as well as
298 gst_rtp_dv_depay_process (GstBaseRTPDepayload * base, GstBuffer * in)
300 GstBuffer *out = NULL;
303 guint payload_len, location;
304 GstRTPDVDepay *dvdepay = GST_RTP_DV_DEPAY (base);
307 marker = gst_rtp_buffer_get_marker (in);
309 /* Check if the received packet contains (the start of) a new frame, we do
310 * this by checking the RTP timestamp. */
311 rtp_ts = gst_rtp_buffer_get_timestamp (in);
313 /* we cannot copy the packet yet if the marker is set, we will do that below
314 * after taking out the data */
315 if (dvdepay->prev_ts != -1 && rtp_ts != dvdepay->prev_ts && !marker) {
316 /* the timestamp changed */
317 GST_DEBUG_OBJECT (dvdepay, "new frame with ts %u, old ts %u", rtp_ts,
320 /* return copy of accumulator. */
321 out = gst_buffer_copy (dvdepay->acc);
324 /* Extract the payload */
325 payload_len = gst_rtp_buffer_get_payload_len (in);
326 payload = gst_rtp_buffer_get_payload (in);
328 /* copy all DIF chunks in their place. */
329 while (payload_len >= 80) {
330 /* Calculate where in the frame the payload should go */
331 location = calculate_difblock_location (payload);
333 /* Check if we received a header. We will not pass on frames until
334 * we've received a header, otherwise the DV decoder goes wacko. */
336 dvdepay->have_header = TRUE;
338 /* And copy it in, provided the location is sane. */
339 if (location >= 0 && location <= dvdepay->frame_size - 80)
340 memcpy (GST_BUFFER_DATA (dvdepay->acc) + location, payload, 80);
347 /* The marker marks the end of a frame that we need to push. The next frame
348 * will change the timestamp but we won't copy the accumulator again because
349 * we set the prev_ts to -1. */
350 out = gst_buffer_copy (dvdepay->acc);
351 GST_DEBUG_OBJECT (dvdepay, "marker bit complete frame %u", rtp_ts);
352 dvdepay->prev_ts = -1;
354 /* save last timestamp */
355 dvdepay->prev_ts = rtp_ts;
361 gst_rtp_dv_depay_reset (GstRTPDVDepay * depay)
364 gst_buffer_unref (depay->acc);
368 depay->have_header = FALSE;
372 static GstStateChangeReturn
373 gst_rtp_dv_depay_change_state (GstElement * element, GstStateChange transition)
375 GstStateChangeReturn ret;
376 GstRTPDVDepay *depay = GST_RTP_DV_DEPAY (element);
378 switch (transition) {
379 case GST_STATE_CHANGE_READY_TO_PAUSED:
380 gst_rtp_dv_depay_reset (depay);
386 ret = GST_CALL_PARENT_WITH_DEFAULT (GST_ELEMENT_CLASS, change_state,
387 (element, transition), GST_STATE_CHANGE_FAILURE);
389 switch (transition) {
390 case GST_STATE_CHANGE_PAUSED_TO_READY:
391 gst_rtp_dv_depay_reset (depay);
400 gst_rtp_dv_depay_plugin_init (GstPlugin * plugin)
402 return gst_element_register (plugin, "rtpdvdepay",
403 GST_RANK_NONE, GST_TYPE_RTP_DV_DEPAY);