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dc1394src: Implement LATENCY query

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Based on the LATENCY query code in v4l2src and the patch
by Tristan Matthews. Fixes bug #625520.
This commit is contained in:
Sebastian Dröge 2011-05-26 09:22:31 +02:00
parent d8eb9f127f
commit 0bb2a4d229
1 changed files with 55 additions and 4 deletions
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59
ext/dc1394/gstdc1394.c
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@ -98,6 +98,7 @@ static void gst_dc1394_framerate_const_to_frac (gint framerateconst,
GValue * framefrac);
static gboolean
gst_dc1394_change_camera_transmission (GstDc1394 * src, gboolean on);
static gboolean gst_dc1394_query (GstBaseSrc * bsrc, GstQuery * query);
static void
gst_dc1394_base_init (gpointer g_class)
@ -157,12 +158,12 @@ gst_dc1394_class_init (GstDc1394Class * klass)
gstbasesrc_class->get_caps = gst_dc1394_getcaps;
gstbasesrc_class->set_caps = gst_dc1394_setcaps;
gstbasesrc_class->query = gst_dc1394_query;
gstbasesrc_class->get_times = gst_dc1394_get_times;
gstpushsrc_class->create = gst_dc1394_create;
gstelement_class->change_state = GST_DEBUG_FUNCPTR (gst_dc1394_change_state);
}
static void
@ -182,7 +183,6 @@ gst_dc1394_init (GstDc1394 * src, GstDc1394Class * g_class)
gst_dc1394_src_fixate);
gst_base_src_set_live (GST_BASE_SRC (src), TRUE);
}
static void
@ -205,6 +205,59 @@ gst_dc1394_src_fixate (GstPad * pad, GstCaps * caps)
gst_object_unref (GST_OBJECT (src));
}
static gboolean
gst_dc1394_query (GstBaseSrc * bsrc, GstQuery * query)
{
gboolean res = TRUE;
GstDc1394 *src = GST_DC1394 (bsrc);
switch (GST_QUERY_TYPE (query)) {
case GST_QUERY_LATENCY:
{
GstClockTime min_latency, max_latency;
if (!src->camera) {
GST_WARNING_OBJECT (src,
"Can't give latency since device isn't open !");
res = FALSE;
goto done;
}
if (src->rate_denominator <= 0 || src->rate_numerator <= 0) {
GST_WARNING_OBJECT (bsrc,
"Can't give latency since framerate isn't fixated !");
res = FALSE;
goto done;
}
/* min latency is the time to capture one frame */
min_latency = gst_util_uint64_scale (GST_SECOND,
src->rate_denominator, src->rate_numerator);
/* max latency is total duration of the frame buffer */
max_latency = gst_util_uint64_scale (src->bufsize,
GST_SECOND * src->rate_denominator, src->rate_numerator);
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;
}
static void
gst_dc1394_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec)
@ -280,11 +333,9 @@ gst_dc1394_getcaps (GstBaseSrc * bsrc)
return gst_caps_copy (gsrc->caps);
}
static gboolean
gst_dc1394_setcaps (GstBaseSrc * bsrc, GstCaps * caps)
{
gboolean res = TRUE;
GstDc1394 *dc1394;
gint width, height, rate_denominator, rate_numerator;