Commit 7c69e902 authored by Tim-Philipp Müller's avatar Tim-Philipp Müller 🐠
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sys/v4l2/: Implement LATENCY queries in the crudest way possible so I don't...

sys/v4l2/: Implement LATENCY queries in the crudest way possible so I don't have to use sync=false any longer when te...

Original commit message from CVS:
* sys/v4l2/gstv4l2src.c:
* sys/v4l2/gstv4l2src.h:
* sys/v4l2/v4l2src_calls.c:
Implement LATENCY queries in the crudest way possible so I don't
have to use sync=false any longer when testing with videosinks.
parent 3ee2bed9
2007-09-05 Tim-Philipp Müller <tim at centricular dot net>
* sys/v4l2/gstv4l2src.c:
* sys/v4l2/gstv4l2src.h:
* sys/v4l2/v4l2src_calls.c:
Implement LATENCY queries in the crudest way possible so I don't
have to use sync=false any longer when testing with videosinks.
2007-09-05 Tim-Philipp Müller <tim at centricular dot net>
* configure.ac:
......
......@@ -237,6 +237,7 @@ static gboolean gst_v4l2src_start (GstBaseSrc * src);
static gboolean gst_v4l2src_stop (GstBaseSrc * src);
static gboolean gst_v4l2src_set_caps (GstBaseSrc * src, GstCaps * caps);
static GstCaps *gst_v4l2src_get_caps (GstBaseSrc * src);
static gboolean gst_v4l2src_query (GstBaseSrc * bsrc, GstQuery * query);
static GstFlowReturn gst_v4l2src_create (GstPushSrc * src, GstBuffer ** out);
static void gst_v4l2src_fixate (GstPad * pad, GstCaps * caps);
......@@ -289,12 +290,13 @@ gst_v4l2src_class_init (GstV4l2SrcClass * klass)
GST_V4L2_MIN_BUFFERS, GST_V4L2_MAX_BUFFERS, GST_V4L2_MIN_BUFFERS,
G_PARAM_READWRITE));
basesrc_class->get_caps = gst_v4l2src_get_caps;
basesrc_class->set_caps = gst_v4l2src_set_caps;
basesrc_class->start = gst_v4l2src_start;
basesrc_class->stop = gst_v4l2src_stop;
basesrc_class->get_caps = GST_DEBUG_FUNCPTR (gst_v4l2src_get_caps);
basesrc_class->set_caps = GST_DEBUG_FUNCPTR (gst_v4l2src_set_caps);
basesrc_class->start = GST_DEBUG_FUNCPTR (gst_v4l2src_start);
basesrc_class->stop = GST_DEBUG_FUNCPTR (gst_v4l2src_stop);
basesrc_class->query = GST_DEBUG_FUNCPTR (gst_v4l2src_query);
pushsrc_class->create = gst_v4l2src_create;
pushsrc_class->create = GST_DEBUG_FUNCPTR (gst_v4l2src_create);
}
static void
......@@ -316,6 +318,9 @@ gst_v4l2src_init (GstV4l2Src * v4l2src, GstV4l2SrcClass * klass)
gst_base_src_set_format (GST_BASE_SRC (v4l2src), GST_FORMAT_TIME);
gst_base_src_set_live (GST_BASE_SRC (v4l2src), TRUE);
v4l2src->fps_d = 0;
v4l2src->fps_n = 0;
}
......@@ -865,6 +870,55 @@ gst_v4l2src_set_caps (GstBaseSrc * src, GstCaps * caps)
return TRUE;
}
static gboolean
gst_v4l2src_query (GstBaseSrc * bsrc, GstQuery * query)
{
GstV4l2Src *src;
gboolean res = FALSE;
src = GST_V4L2SRC (bsrc);
switch (GST_QUERY_TYPE (query)) {
case GST_QUERY_LATENCY:{
GstClockTime min_latency, max_latency;
/* device must be open */
if (!GST_V4L2_IS_OPEN (src->v4l2object))
goto done;
/* we must have a framerate */
if (src->fps_n <= 0 || src->fps_d <= 0)
goto done;
/* min latency is the time to capture one frame */
min_latency =
gst_util_uint64_scale_int (GST_SECOND, src->fps_d, src->fps_n);
/* max latency is total duration of the frame buffer */
/* FIXME: what to use here? */
max_latency = 1 * min_latency;
GST_DEBUG_OBJECT (bsrc,
"report latency min %" GST_TIME_FORMAT " max %" GST_TIME_FORMAT,
GST_TIME_ARGS (min_latency), GST_TIME_ARGS (max_latency));
/* we are always live, the min latency is 1 frame and the max latency is
* the complete buffer of frames. */
gst_query_set_latency (query, TRUE, min_latency, max_latency);
res = TRUE;
break;
}
default:
res = GST_BASE_SRC_CLASS (parent_class)->query (bsrc, query);
break;
}
done:
return res;
}
/* start and stop are not symmetric -- start will open the device, but not start
* capture. it's setcaps that will start capture, which is called via basesrc's
* negotiate method. stop will both stop capture and close the device.
......@@ -901,6 +955,9 @@ gst_v4l2src_stop (GstBaseSrc * src)
if (!gst_v4l2_object_stop (v4l2src->v4l2object))
return FALSE;
v4l2src->fps_d = 0;
v4l2src->fps_n = 0;
return TRUE;
}
......@@ -950,9 +1007,20 @@ gst_v4l2src_get_read (GstV4l2Src * v4l2src, GstBuffer ** buf)
GST_OBJECT_UNLOCK (v4l2src);
if (clock) {
GstClockTime latency;
/* the time now is the time of the clock minus the base time */
timestamp = gst_clock_get_time (clock) - timestamp;
gst_object_unref (clock);
latency =
gst_util_uint64_scale_int (GST_SECOND, v4l2src->fps_d,
v4l2src->fps_n);
if (timestamp > latency)
timestamp -= latency;
else
timestamp = 0;
}
/* FIXME: use the timestamp from the buffer itself! */
......
......@@ -106,6 +106,8 @@ struct _GstV4l2Src
gboolean is_capturing;
guint64 offset;
gint fps_d, fps_n; /* framerate if device is open */
};
struct _GstV4l2SrcClass
......
......@@ -968,6 +968,9 @@ gst_v4l2src_set_capture (GstV4l2Src * v4l2src, guint32 pixelformat,
|| stream.parm.capture.timeperframe.denominator != fps_n)
goto invalid_framerate;
}
v4l2src->fps_d = fps_d;
v4l2src->fps_n = fps_n;
}
return TRUE;
......
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