3 * Copyright (C) 2001-2002 Ronald Bultje <rbultje@ronald.bitfreak.net>
4 * 2006 Edgard Lima <edgard.lima@indt.org.br>
6 * gstv4l2src.c: Video4Linux2 source element
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Library General Public
10 * License as published by the Free Software Foundation; either
11 * version 2 of the License, or (at your option) any later version.
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Library General Public License for more details.
18 * You should have received a copy of the GNU Library General Public
19 * License along with this library; if not, write to the
20 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
21 * Boston, MA 02111-1307, USA.
25 * SECTION:element-v4l2src
27 * v4l2src can be used to capture video from v4l2 devices, like webcams and tv
31 * <title>Example launch lines</title>
33 * gst-launch v4l2src ! xvimagesink
34 * ]| This pipeline shows the video captured from /dev/video0 tv card and for
37 * gst-launch v4l2src ! jpegdec ! xvimagesink
38 * ]| This pipeline shows the video captured from a webcam that delivers jpeg
51 #include "v4l2src_calls.h"
54 #include "gstv4l2colorbalance.h"
55 #include "gstv4l2tuner.h"
57 #include "gstv4l2xoverlay.h"
59 #include "gstv4l2vidorient.h"
61 #include "gst/gst-i18n-plugin.h"
63 GST_DEBUG_CATEGORY (v4l2src_debug);
64 #define GST_CAT_DEFAULT v4l2src_debug
66 #define PROP_DEF_QUEUE_SIZE 2
67 #define PROP_DEF_ALWAYS_COPY TRUE
68 #define PROP_DEF_DECIMATE 1
70 #define DEFAULT_PROP_DEVICE "/dev/video0"
75 V4L2_STD_OBJECT_PROPS,
81 GST_IMPLEMENT_V4L2_PROBE_METHODS (GstV4l2SrcClass, gst_v4l2src);
82 GST_IMPLEMENT_V4L2_COLOR_BALANCE_METHODS (GstV4l2Src, gst_v4l2src);
83 GST_IMPLEMENT_V4L2_TUNER_METHODS (GstV4l2Src, gst_v4l2src);
85 GST_IMPLEMENT_V4L2_XOVERLAY_METHODS (GstV4l2Src, gst_v4l2src);
87 GST_IMPLEMENT_V4L2_VIDORIENT_METHODS (GstV4l2Src, gst_v4l2src);
89 static void gst_v4l2src_uri_handler_init (gpointer g_iface,
93 gst_v4l2src_iface_supported (GstImplementsInterface * iface, GType iface_type)
95 GstV4l2Object *v4l2object = GST_V4L2SRC (iface)->v4l2object;
98 if (!(iface_type == GST_TYPE_TUNER ||
99 iface_type == GST_TYPE_X_OVERLAY ||
100 iface_type == GST_TYPE_COLOR_BALANCE ||
101 iface_type == GST_TYPE_VIDEO_ORIENTATION))
104 if (!(iface_type == GST_TYPE_TUNER ||
105 iface_type == GST_TYPE_COLOR_BALANCE ||
106 iface_type == GST_TYPE_VIDEO_ORIENTATION))
110 if (v4l2object->video_fd == -1)
114 if (iface_type == GST_TYPE_X_OVERLAY && !GST_V4L2_IS_OVERLAY (v4l2object))
122 gst_v4l2src_interface_init (GstImplementsInterfaceClass * klass)
125 * default virtual functions
127 klass->supported = gst_v4l2src_iface_supported;
131 gst_v4l2src_init_interfaces (GType type)
133 static const GInterfaceInfo urihandler_info = {
134 gst_v4l2src_uri_handler_init,
139 static const GInterfaceInfo v4l2iface_info = {
140 (GInterfaceInitFunc) gst_v4l2src_interface_init,
144 static const GInterfaceInfo v4l2_tuner_info = {
145 (GInterfaceInitFunc) gst_v4l2src_tuner_interface_init,
150 /* FIXME: does GstXOverlay for v4l2src make sense in a GStreamer context? */
151 static const GInterfaceInfo v4l2_xoverlay_info = {
152 (GInterfaceInitFunc) gst_v4l2src_xoverlay_interface_init,
157 static const GInterfaceInfo v4l2_colorbalance_info = {
158 (GInterfaceInitFunc) gst_v4l2src_color_balance_interface_init,
162 static const GInterfaceInfo v4l2_videoorientation_info = {
163 (GInterfaceInitFunc) gst_v4l2src_video_orientation_interface_init,
167 static const GInterfaceInfo v4l2_propertyprobe_info = {
168 (GInterfaceInitFunc) gst_v4l2src_property_probe_interface_init,
173 g_type_add_interface_static (type, GST_TYPE_URI_HANDLER, &urihandler_info);
174 g_type_add_interface_static (type,
175 GST_TYPE_IMPLEMENTS_INTERFACE, &v4l2iface_info);
176 g_type_add_interface_static (type, GST_TYPE_TUNER, &v4l2_tuner_info);
178 g_type_add_interface_static (type, GST_TYPE_X_OVERLAY, &v4l2_xoverlay_info);
180 g_type_add_interface_static (type,
181 GST_TYPE_COLOR_BALANCE, &v4l2_colorbalance_info);
182 g_type_add_interface_static (type,
183 GST_TYPE_VIDEO_ORIENTATION, &v4l2_videoorientation_info);
184 g_type_add_interface_static (type, GST_TYPE_PROPERTY_PROBE,
185 &v4l2_propertyprobe_info);
188 GST_BOILERPLATE_FULL (GstV4l2Src, gst_v4l2src, GstPushSrc, GST_TYPE_PUSH_SRC,
189 gst_v4l2src_init_interfaces);
191 static void gst_v4l2src_dispose (GObject * object);
192 static void gst_v4l2src_finalize (GstV4l2Src * v4l2src);
194 /* element methods */
195 static GstStateChangeReturn gst_v4l2src_change_state (GstElement * element,
196 GstStateChange transition);
198 /* basesrc methods */
199 static gboolean gst_v4l2src_start (GstBaseSrc * src);
200 static gboolean gst_v4l2src_unlock (GstBaseSrc * src);
201 static gboolean gst_v4l2src_unlock_stop (GstBaseSrc * src);
202 static gboolean gst_v4l2src_stop (GstBaseSrc * src);
203 static gboolean gst_v4l2src_set_caps (GstBaseSrc * src, GstCaps * caps);
204 static GstCaps *gst_v4l2src_get_caps (GstBaseSrc * src);
205 static gboolean gst_v4l2src_query (GstBaseSrc * bsrc, GstQuery * query);
206 static GstFlowReturn gst_v4l2src_create (GstPushSrc * src, GstBuffer ** out);
207 static void gst_v4l2src_fixate (GstBaseSrc * basesrc, GstCaps * caps);
208 static gboolean gst_v4l2src_negotiate (GstBaseSrc * basesrc);
210 static void gst_v4l2src_set_property (GObject * object, guint prop_id,
211 const GValue * value, GParamSpec * pspec);
212 static void gst_v4l2src_get_property (GObject * object, guint prop_id,
213 GValue * value, GParamSpec * pspec);
215 /* get_frame io methods */
217 gst_v4l2src_get_read (GstV4l2Src * v4l2src, GstBuffer ** buf);
219 gst_v4l2src_get_mmap (GstV4l2Src * v4l2src, GstBuffer ** buf);
222 gst_v4l2src_base_init (gpointer g_class)
224 GstElementClass *gstelement_class = GST_ELEMENT_CLASS (g_class);
225 GstV4l2SrcClass *gstv4l2src_class = GST_V4L2SRC_CLASS (g_class);
226 GstPadTemplate *pad_template;
228 gstv4l2src_class->v4l2_class_devices = NULL;
230 GST_DEBUG_CATEGORY_INIT (v4l2src_debug, "v4l2src", 0, "V4L2 source element");
232 gst_element_class_set_details_simple (gstelement_class,
233 "Video (video4linux2) Source", "Source/Video",
234 "Reads frames from a Video4Linux2 device",
235 "Edgard Lima <edgard.lima@indt.org.br>,"
236 " Stefan Kost <ensonic@users.sf.net>");
239 gst_pad_template_new ("src", GST_PAD_SRC, GST_PAD_ALWAYS,
240 gst_v4l2_object_get_all_caps ());
241 gst_element_class_add_pad_template (gstelement_class, pad_template);
242 gst_object_unref (pad_template);
246 gst_v4l2src_class_init (GstV4l2SrcClass * klass)
248 GObjectClass *gobject_class;
249 GstElementClass *element_class;
250 GstBaseSrcClass *basesrc_class;
251 GstPushSrcClass *pushsrc_class;
253 gobject_class = G_OBJECT_CLASS (klass);
254 element_class = GST_ELEMENT_CLASS (klass);
255 basesrc_class = GST_BASE_SRC_CLASS (klass);
256 pushsrc_class = GST_PUSH_SRC_CLASS (klass);
258 gobject_class->dispose = gst_v4l2src_dispose;
259 gobject_class->finalize = (GObjectFinalizeFunc) gst_v4l2src_finalize;
260 gobject_class->set_property = gst_v4l2src_set_property;
261 gobject_class->get_property = gst_v4l2src_get_property;
263 element_class->change_state = gst_v4l2src_change_state;
265 gst_v4l2_object_install_properties_helper (gobject_class,
266 DEFAULT_PROP_DEVICE);
267 g_object_class_install_property (gobject_class, PROP_QUEUE_SIZE,
268 g_param_spec_uint ("queue-size", "Queue size",
269 "Number of buffers to be enqueud in the driver in streaming mode",
270 GST_V4L2_MIN_BUFFERS, GST_V4L2_MAX_BUFFERS, PROP_DEF_QUEUE_SIZE,
271 G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
272 g_object_class_install_property (gobject_class, PROP_ALWAYS_COPY,
273 g_param_spec_boolean ("always-copy", "Always Copy",
274 "If the buffer will or not be used directly from mmap",
275 PROP_DEF_ALWAYS_COPY, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
277 * GstV4l2Src:decimate
279 * Only use every nth frame
283 g_object_class_install_property (gobject_class, PROP_DECIMATE,
284 g_param_spec_int ("decimate", "Decimate",
285 "Only use every nth frame", 1, G_MAXINT,
286 PROP_DEF_DECIMATE, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
288 basesrc_class->get_caps = GST_DEBUG_FUNCPTR (gst_v4l2src_get_caps);
289 basesrc_class->set_caps = GST_DEBUG_FUNCPTR (gst_v4l2src_set_caps);
290 basesrc_class->start = GST_DEBUG_FUNCPTR (gst_v4l2src_start);
291 basesrc_class->unlock = GST_DEBUG_FUNCPTR (gst_v4l2src_unlock);
292 basesrc_class->unlock_stop = GST_DEBUG_FUNCPTR (gst_v4l2src_unlock_stop);
293 basesrc_class->stop = GST_DEBUG_FUNCPTR (gst_v4l2src_stop);
294 basesrc_class->query = GST_DEBUG_FUNCPTR (gst_v4l2src_query);
295 basesrc_class->fixate = GST_DEBUG_FUNCPTR (gst_v4l2src_fixate);
296 basesrc_class->negotiate = GST_DEBUG_FUNCPTR (gst_v4l2src_negotiate);
298 pushsrc_class->create = GST_DEBUG_FUNCPTR (gst_v4l2src_create);
302 gst_v4l2src_init (GstV4l2Src * v4l2src, GstV4l2SrcClass * klass)
304 /* fixme: give an update_fps_function */
305 v4l2src->v4l2object = gst_v4l2_object_new (GST_ELEMENT (v4l2src),
306 V4L2_BUF_TYPE_VIDEO_CAPTURE, DEFAULT_PROP_DEVICE,
307 gst_v4l2_get_input, gst_v4l2_set_input, NULL);
309 /* number of buffers requested */
310 v4l2src->num_buffers = PROP_DEF_QUEUE_SIZE;
312 v4l2src->always_copy = PROP_DEF_ALWAYS_COPY;
313 v4l2src->decimate = PROP_DEF_DECIMATE;
315 v4l2src->is_capturing = FALSE;
317 gst_base_src_set_format (GST_BASE_SRC (v4l2src), GST_FORMAT_TIME);
318 gst_base_src_set_live (GST_BASE_SRC (v4l2src), TRUE);
326 gst_v4l2src_dispose (GObject * object)
328 GstV4l2Src *v4l2src = GST_V4L2SRC (object);
330 if (v4l2src->probed_caps) {
331 gst_caps_unref (v4l2src->probed_caps);
334 G_OBJECT_CLASS (parent_class)->dispose (object);
339 gst_v4l2src_finalize (GstV4l2Src * v4l2src)
341 gst_v4l2_object_destroy (v4l2src->v4l2object);
343 G_OBJECT_CLASS (parent_class)->finalize ((GObject *) (v4l2src));
348 gst_v4l2src_set_property (GObject * object,
349 guint prop_id, const GValue * value, GParamSpec * pspec)
351 GstV4l2Src *v4l2src = GST_V4L2SRC (object);
353 if (!gst_v4l2_object_set_property_helper (v4l2src->v4l2object,
354 prop_id, value, pspec)) {
356 case PROP_QUEUE_SIZE:
357 v4l2src->num_buffers = g_value_get_uint (value);
359 case PROP_ALWAYS_COPY:
360 v4l2src->always_copy = g_value_get_boolean (value);
363 v4l2src->decimate = g_value_get_int (value);
366 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
374 gst_v4l2src_get_property (GObject * object,
375 guint prop_id, GValue * value, GParamSpec * pspec)
377 GstV4l2Src *v4l2src = GST_V4L2SRC (object);
379 if (!gst_v4l2_object_get_property_helper (v4l2src->v4l2object,
380 prop_id, value, pspec)) {
382 case PROP_QUEUE_SIZE:
383 g_value_set_uint (value, v4l2src->num_buffers);
385 case PROP_ALWAYS_COPY:
386 g_value_set_boolean (value, v4l2src->always_copy);
389 g_value_set_int (value, v4l2src->decimate);
392 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
399 /* this function is a bit of a last resort */
401 gst_v4l2src_fixate (GstBaseSrc * basesrc, GstCaps * caps)
403 GstStructure *structure;
406 GST_DEBUG_OBJECT (basesrc, "fixating caps %" GST_PTR_FORMAT, caps);
408 for (i = 0; i < gst_caps_get_size (caps); ++i) {
411 structure = gst_caps_get_structure (caps, i);
413 /* FIXME such sizes? we usually fixate to something in the 320x200
415 /* We are fixating to greater possble size (limited to GST_V4L2_MAX_SIZE)
416 and the maximum framerate resolution for that size */
417 gst_structure_fixate_field_nearest_int (structure, "width",
419 gst_structure_fixate_field_nearest_int (structure, "height",
421 gst_structure_fixate_field_nearest_fraction (structure, "framerate",
424 v = gst_structure_get_value (structure, "format");
425 if (v && G_VALUE_TYPE (v) != GST_TYPE_FOURCC) {
428 g_return_if_fail (G_VALUE_TYPE (v) == GST_TYPE_LIST);
430 fourcc = gst_value_get_fourcc (gst_value_list_get_value (v, 0));
431 gst_structure_set (structure, "format", GST_TYPE_FOURCC, fourcc, NULL);
435 GST_DEBUG_OBJECT (basesrc, "fixated caps %" GST_PTR_FORMAT, caps);
440 gst_v4l2src_negotiate (GstBaseSrc * basesrc)
443 GstCaps *caps = NULL;
444 GstCaps *peercaps = NULL;
445 gboolean result = FALSE;
447 /* first see what is possible on our source pad */
448 thiscaps = gst_pad_get_caps (GST_BASE_SRC_PAD (basesrc));
449 GST_DEBUG_OBJECT (basesrc, "caps of src: %" GST_PTR_FORMAT, thiscaps);
450 LOG_CAPS (basesrc, thiscaps);
452 /* nothing or anything is allowed, we're done */
453 if (thiscaps == NULL || gst_caps_is_any (thiscaps))
456 /* get the peer caps */
457 peercaps = gst_pad_peer_get_caps (GST_BASE_SRC_PAD (basesrc));
458 GST_DEBUG_OBJECT (basesrc, "caps of peer: %" GST_PTR_FORMAT, peercaps);
459 LOG_CAPS (basesrc, peercaps);
460 if (peercaps && !gst_caps_is_any (peercaps)) {
461 GstCaps *icaps = NULL;
464 /* Prefer the first caps we are compatible with that the peer proposed */
465 for (i = 0; i < gst_caps_get_size (peercaps); i++) {
466 /* get intersection */
467 GstCaps *ipcaps = gst_caps_copy_nth (peercaps, i);
469 GST_DEBUG_OBJECT (basesrc, "peer: %" GST_PTR_FORMAT, ipcaps);
470 LOG_CAPS (basesrc, ipcaps);
472 icaps = gst_caps_intersect (thiscaps, ipcaps);
473 gst_caps_unref (ipcaps);
475 if (!gst_caps_is_empty (icaps))
478 gst_caps_unref (icaps);
482 GST_DEBUG_OBJECT (basesrc, "intersect: %" GST_PTR_FORMAT, icaps);
483 LOG_CAPS (basesrc, icaps);
485 /* If there are multiple intersections pick the one with the smallest
486 * resolution strictly bigger then the first peer caps */
487 if (gst_caps_get_size (icaps) > 1) {
488 GstStructure *s = gst_caps_get_structure (peercaps, 0);
494 int width = G_MAXINT, height = G_MAXINT;
496 if (gst_structure_get_int (s, "width", &twidth)
497 && gst_structure_get_int (s, "height", &theight)) {
499 /* Walk the structure backwards to get the first entry of the
500 * smallest resolution bigger (or equal to) the preferred resolution)
502 for (i = gst_caps_get_size (icaps) - 1; i >= 0; i--) {
503 GstStructure *is = gst_caps_get_structure (icaps, i);
507 if (gst_structure_get_int (is, "width", &w)
508 && gst_structure_get_int (is, "height", &h)) {
509 if (w >= twidth && w <= width && h >= theight && h <= height) {
518 caps = gst_caps_copy_nth (icaps, best);
519 gst_caps_unref (icaps);
524 gst_caps_unref (thiscaps);
526 /* no peer or peer have ANY caps, work with our own caps then */
530 gst_caps_unref (peercaps);
532 caps = gst_caps_make_writable (caps);
533 gst_caps_truncate (caps);
536 if (!gst_caps_is_empty (caps)) {
537 gst_pad_fixate_caps (GST_BASE_SRC_PAD (basesrc), caps);
538 GST_DEBUG_OBJECT (basesrc, "fixated to: %" GST_PTR_FORMAT, caps);
539 LOG_CAPS (basesrc, caps);
541 if (gst_caps_is_any (caps)) {
542 /* hmm, still anything, so element can do anything and
543 * nego is not needed */
545 } else if (gst_caps_is_fixed (caps)) {
546 /* yay, fixed caps, use those then */
547 if (gst_pad_set_caps (GST_BASE_SRC_PAD (basesrc), caps))
551 gst_caps_unref (caps);
557 GST_DEBUG_OBJECT (basesrc, "no negotiation needed");
559 gst_caps_unref (thiscaps);
565 gst_v4l2src_get_caps (GstBaseSrc * src)
567 GstV4l2Src *v4l2src = GST_V4L2SRC (src);
572 if (!GST_V4L2_IS_OPEN (v4l2src->v4l2object)) {
575 gst_caps_copy (gst_pad_get_pad_template_caps (GST_BASE_SRC_PAD
579 if (v4l2src->probed_caps)
580 return gst_caps_ref (v4l2src->probed_caps);
582 formats = gst_v4l2_object_get_format_list (v4l2src->v4l2object);
584 ret = gst_caps_new_empty ();
586 for (walk = formats; walk; walk = walk->next) {
587 struct v4l2_fmtdesc *format;
589 GstStructure *template;
591 format = (struct v4l2_fmtdesc *) walk->data;
593 template = gst_v4l2_object_v4l2fourcc_to_structure (format->pixelformat);
599 gst_v4l2_object_probe_caps_for_format (v4l2src->v4l2object,
600 format->pixelformat, template);
602 gst_caps_append (ret, tmp);
604 gst_structure_free (template);
606 GST_DEBUG_OBJECT (v4l2src, "unknown format %u", format->pixelformat);
610 v4l2src->probed_caps = gst_caps_ref (ret);
612 GST_INFO_OBJECT (v4l2src, "probed caps: %" GST_PTR_FORMAT, ret);
618 gst_v4l2src_set_caps (GstBaseSrc * src, GstCaps * caps)
623 struct v4l2_fmtdesc *format;
627 v4l2src = GST_V4L2SRC (src);
629 /* if we're not open, punt -- we'll get setcaps'd later via negotiate */
630 if (!GST_V4L2_IS_OPEN (v4l2src->v4l2object))
633 /* make sure we stop capturing and dealloc buffers */
634 if (GST_V4L2_IS_ACTIVE (v4l2src->v4l2object)) {
635 /* both will throw an element-error on failure */
636 if (!gst_v4l2src_capture_stop (v4l2src))
638 if (!gst_v4l2src_capture_deinit (v4l2src))
642 /* we want our own v4l2 type of fourcc codes */
643 if (!gst_v4l2_object_get_caps_info (v4l2src->v4l2object, caps, &format, &w,
644 &h, &interlaced, &fps_n, &fps_d, &size)) {
645 GST_INFO_OBJECT (v4l2src,
646 "can't get capture format from caps %" GST_PTR_FORMAT, caps);
650 GST_DEBUG_OBJECT (v4l2src, "trying to set_capture %dx%d at %d/%d fps, "
651 "format %s", w, h, fps_n, fps_d, format->description);
653 if (!gst_v4l2src_set_capture (v4l2src, format->pixelformat, w, h,
654 interlaced, fps_n, fps_d))
655 /* error already posted */
658 if (!gst_v4l2src_capture_init (v4l2src, caps))
661 if (v4l2src->use_mmap) {
662 v4l2src->get_frame = gst_v4l2src_get_mmap;
664 v4l2src->get_frame = gst_v4l2src_get_read;
667 if (!gst_v4l2src_capture_start (v4l2src))
670 /* now store the expected output size */
671 v4l2src->frame_byte_size = size;
677 gst_v4l2src_query (GstBaseSrc * bsrc, GstQuery * query)
681 gboolean res = FALSE;
683 src = GST_V4L2SRC (bsrc);
685 switch (GST_QUERY_TYPE (query)) {
686 case GST_QUERY_LATENCY:{
687 GstClockTime min_latency, max_latency;
689 /* device must be open */
690 if (!GST_V4L2_IS_OPEN (src->v4l2object)) {
691 GST_WARNING_OBJECT (src,
692 "Can't give latency since device isn't open !");
696 /* we must have a framerate */
697 if (src->fps_n <= 0 || src->fps_d <= 0) {
698 GST_WARNING_OBJECT (src,
699 "Can't give latency since framerate isn't fixated !");
703 /* min latency is the time to capture one frame */
705 gst_util_uint64_scale_int (GST_SECOND, src->fps_d, src->fps_n);
707 /* max latency is total duration of the frame buffer */
708 max_latency = src->num_buffers * min_latency;
710 GST_DEBUG_OBJECT (bsrc,
711 "report latency min %" GST_TIME_FORMAT " max %" GST_TIME_FORMAT,
712 GST_TIME_ARGS (min_latency), GST_TIME_ARGS (max_latency));
714 /* we are always live, the min latency is 1 frame and the max latency is
715 * the complete buffer of frames. */
716 gst_query_set_latency (query, TRUE, min_latency, max_latency);
722 res = GST_BASE_SRC_CLASS (parent_class)->query (bsrc, query);
731 /* start and stop are not symmetric -- start will open the device, but not start
732 * capture. it's setcaps that will start capture, which is called via basesrc's
733 * negotiate method. stop will both stop capture and close the device.
736 gst_v4l2src_start (GstBaseSrc * src)
738 GstV4l2Src *v4l2src = GST_V4L2SRC (src);
742 /* activate settings for first frame */
743 v4l2src->ctrl_time = 0;
744 gst_object_sync_values (G_OBJECT (src), v4l2src->ctrl_time);
750 gst_v4l2src_unlock (GstBaseSrc * src)
752 GstV4l2Src *v4l2src = GST_V4L2SRC (src);
754 GST_LOG_OBJECT (src, "Flushing");
755 gst_poll_set_flushing (v4l2src->v4l2object->poll, TRUE);
761 gst_v4l2src_unlock_stop (GstBaseSrc * src)
763 GstV4l2Src *v4l2src = GST_V4L2SRC (src);
765 GST_LOG_OBJECT (src, "No longer flushing");
766 gst_poll_set_flushing (v4l2src->v4l2object->poll, FALSE);
772 gst_v4l2src_stop (GstBaseSrc * src)
774 GstV4l2Src *v4l2src = GST_V4L2SRC (src);
776 if (GST_V4L2_IS_ACTIVE (v4l2src->v4l2object)
777 && !gst_v4l2src_capture_stop (v4l2src))
780 if (v4l2src->v4l2object->buffer != NULL) {
781 if (!gst_v4l2src_capture_deinit (v4l2src))
791 static GstStateChangeReturn
792 gst_v4l2src_change_state (GstElement * element, GstStateChange transition)
794 GstStateChangeReturn ret = GST_STATE_CHANGE_SUCCESS;
795 GstV4l2Src *v4l2src = GST_V4L2SRC (element);
797 switch (transition) {
798 case GST_STATE_CHANGE_NULL_TO_READY:
799 /* open the device */
800 if (!gst_v4l2_object_start (v4l2src->v4l2object))
801 return GST_STATE_CHANGE_FAILURE;
807 ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
809 switch (transition) {
810 case GST_STATE_CHANGE_READY_TO_NULL:
811 /* close the device */
812 if (!gst_v4l2_object_stop (v4l2src->v4l2object))
813 return GST_STATE_CHANGE_FAILURE;
815 if (v4l2src->probed_caps) {
816 gst_caps_unref (v4l2src->probed_caps);
817 v4l2src->probed_caps = NULL;
828 gst_v4l2src_get_read (GstV4l2Src * v4l2src, GstBuffer ** buf)
835 buffersize = v4l2src->frame_byte_size;
836 /* In case the size per frame is unknown assume it's a streaming format (e.g.
837 * mpegts) and grab a reasonable default size instead */
839 buffersize = GST_BASE_SRC (v4l2src)->blocksize;
841 *buf = gst_buffer_new_and_alloc (buffersize);
844 ret = gst_poll_wait (v4l2src->v4l2object->poll, GST_CLOCK_TIME_NONE);
845 if (G_UNLIKELY (ret < 0)) {
848 if (errno == ENXIO) {
849 GST_DEBUG_OBJECT (v4l2src,
850 "v4l2 device doesn't support polling. Disabling");
851 v4l2src->v4l2object->can_poll_device = FALSE;
853 if (errno != EAGAIN && errno != EINTR)
858 v4l2_read (v4l2src->v4l2object->video_fd, GST_BUFFER_DATA (*buf),
860 if (amount == buffersize) {
862 } else if (amount == -1) {
863 if (errno == EAGAIN || errno == EINTR) {
868 /* short reads can happen if a signal interrupts the read */
873 /* we set the buffer metadata in gst_v4l2src_create() */
880 GST_ELEMENT_ERROR (v4l2src, RESOURCE, READ, (NULL),
881 ("select error %d: %s (%d)", ret, g_strerror (errno), errno));
882 return GST_FLOW_ERROR;
886 GST_DEBUG ("stop called");
887 return GST_FLOW_WRONG_STATE;
891 GST_ELEMENT_ERROR (v4l2src, RESOURCE, READ,
892 (_("Error reading %d bytes from device '%s'."),
893 buffersize, v4l2src->v4l2object->videodev), GST_ERROR_SYSTEM);
894 gst_buffer_unref (*buf);
895 return GST_FLOW_ERROR;
900 gst_v4l2src_get_mmap (GstV4l2Src * v4l2src, GstBuffer ** buf)
908 ret = gst_v4l2src_grab_frame (v4l2src, &temp);
909 if (G_UNLIKELY (ret != GST_FLOW_OK))
912 if (v4l2src->frame_byte_size > 0) {
913 size = GST_BUFFER_SIZE (temp);
915 /* if size does not match what we expected, try again */
916 if (size != v4l2src->frame_byte_size) {
917 GST_ELEMENT_WARNING (v4l2src, RESOURCE, READ,
918 (_("Got unexpected frame size of %u instead of %u."),
919 size, v4l2src->frame_byte_size), (NULL));
920 gst_buffer_unref (temp);
935 GST_ELEMENT_ERROR (v4l2src, RESOURCE, READ,
936 (_("Error reading %d bytes on device '%s'."),
937 v4l2src->frame_byte_size, v4l2src->v4l2object->videodev), (NULL));
938 return GST_FLOW_ERROR;
943 gst_v4l2src_create (GstPushSrc * src, GstBuffer ** buf)
945 GstV4l2Src *v4l2src = GST_V4L2SRC (src);
949 for (i = 0; i < v4l2src->decimate - 1; i++) {
950 ret = v4l2src->get_frame (v4l2src, buf);
951 if (ret != GST_FLOW_OK) {
954 gst_buffer_unref (*buf);
957 ret = v4l2src->get_frame (v4l2src, buf);
959 /* set buffer metadata */
960 if (G_LIKELY (ret == GST_FLOW_OK && *buf)) {
962 GstClockTime timestamp;
964 GST_BUFFER_OFFSET (*buf) = v4l2src->offset++;
965 GST_BUFFER_OFFSET_END (*buf) = v4l2src->offset;
967 /* timestamps, LOCK to get clock and base time. */
968 /* FIXME: element clock and base_time is rarely changing */
969 GST_OBJECT_LOCK (v4l2src);
970 if ((clock = GST_ELEMENT_CLOCK (v4l2src))) {
971 /* we have a clock, get base time and ref clock */
972 timestamp = GST_ELEMENT (v4l2src)->base_time;
973 gst_object_ref (clock);
975 /* no clock, can't set timestamps */
976 timestamp = GST_CLOCK_TIME_NONE;
978 GST_OBJECT_UNLOCK (v4l2src);
980 if (G_LIKELY (clock)) {
981 /* the time now is the time of the clock minus the base time */
982 timestamp = gst_clock_get_time (clock) - timestamp;
983 gst_object_unref (clock);
985 /* if we have a framerate adjust timestamp for frame latency */
986 if (GST_CLOCK_TIME_IS_VALID (v4l2src->duration)) {
987 if (timestamp > v4l2src->duration)
988 timestamp -= v4l2src->duration;
994 /* activate settings for next frame */
995 if (GST_CLOCK_TIME_IS_VALID (v4l2src->duration)) {
996 v4l2src->ctrl_time += v4l2src->duration;
998 /* this is not very good (as it should be the next timestamp),
999 * still good enough for linear fades (as long as it is not -1)
1001 v4l2src->ctrl_time = timestamp;
1003 gst_object_sync_values (G_OBJECT (src), v4l2src->ctrl_time);
1004 GST_INFO_OBJECT (src, "sync to %" GST_TIME_FORMAT,
1005 GST_TIME_ARGS (v4l2src->ctrl_time));
1007 /* FIXME: use the timestamp from the buffer itself! */
1008 GST_BUFFER_TIMESTAMP (*buf) = timestamp;
1009 GST_BUFFER_DURATION (*buf) = v4l2src->duration;
1015 /* GstURIHandler interface */
1017 gst_v4l2src_uri_get_type (void)
1023 gst_v4l2src_uri_get_protocols (void)
1025 static gchar *protocols[] = { (char *) "v4l2", NULL };
1030 static const gchar *
1031 gst_v4l2src_uri_get_uri (GstURIHandler * handler)
1033 GstV4l2Src *v4l2src = GST_V4L2SRC (handler);
1035 if (v4l2src->v4l2object->videodev != NULL) {
1038 /* need to return a const string, but also don't want to leak the generated
1039 * string, so just intern it - there's a limited number of video devices
1041 g_snprintf (uri, sizeof (uri), "v4l2://%s", v4l2src->v4l2object->videodev);
1042 return g_intern_string (uri);
1049 gst_v4l2src_uri_set_uri (GstURIHandler * handler, const gchar * uri)
1051 GstV4l2Src *v4l2src = GST_V4L2SRC (handler);
1052 const gchar *device = DEFAULT_PROP_DEVICE;
1054 if (strcmp (uri, "v4l2://") != 0) {
1057 g_object_set (v4l2src, "device", device, NULL);
1064 gst_v4l2src_uri_handler_init (gpointer g_iface, gpointer iface_data)
1066 GstURIHandlerInterface *iface = (GstURIHandlerInterface *) g_iface;
1068 iface->get_type = gst_v4l2src_uri_get_type;
1069 iface->get_protocols = gst_v4l2src_uri_get_protocols;
1070 iface->get_uri = gst_v4l2src_uri_get_uri;
1071 iface->set_uri = gst_v4l2src_uri_set_uri;