playbin2: improve screenshot code

Use appsrc and appsink in the screenshot code to make things nicer.
This commit is contained in:
Wim Taymans 2010-06-05 12:27:12 +02:00
parent f562c8b290
commit 13f6829497

View file

@ -58,33 +58,6 @@ gst_play_marshal_BUFFER__BOXED (GClosure * closure,
gst_value_take_buffer (return_value, v_return);
}
static void
feed_fakesrc (GstElement * src, GstBuffer * buf, GstPad * pad, gpointer data)
{
GstBuffer *in_buf = GST_BUFFER (data);
gst_buffer_set_caps (buf, GST_BUFFER_CAPS (in_buf));
memcpy (GST_BUFFER_DATA (buf), GST_BUFFER_DATA (in_buf),
GST_BUFFER_SIZE (in_buf));
GST_BUFFER_SIZE (buf) = GST_BUFFER_SIZE (in_buf);
GST_DEBUG ("feeding buffer %p, size %u, caps %" GST_PTR_FORMAT,
buf, GST_BUFFER_SIZE (buf), GST_BUFFER_CAPS (buf));
}
static void
save_result (GstElement * sink, GstBuffer * buf, GstPad * pad, gpointer data)
{
GstBuffer **p_buf = (GstBuffer **) data;
*p_buf = gst_buffer_ref (buf);
GST_DEBUG ("received converted buffer %p with caps %" GST_PTR_FORMAT,
*p_buf, GST_BUFFER_CAPS (*p_buf));
}
static gboolean
create_element (const gchar * factory_name, GstElement ** element,
GError ** err)
@ -106,23 +79,24 @@ create_element (const gchar * factory_name, GstElement ** element,
GstBuffer *
gst_play_frame_conv_convert (GstBuffer * buf, GstCaps * to_caps)
{
GstElement *src, *csp, *filter1, *vscale, *filter2, *sink, *pipeline;
GstElement *src, *csp, *vscale, *sink, *pipeline;
GstMessage *msg;
GstBuffer *result = NULL;
GError *error = NULL;
GstBus *bus;
GstCaps *to_caps_no_par;
GstCaps *from_caps;
GstFlowReturn ret;
g_return_val_if_fail (GST_BUFFER_CAPS (buf) != NULL, NULL);
from_caps = GST_BUFFER_CAPS (buf);
g_return_val_if_fail (from_caps != NULL, NULL);
/* videoscale is here to correct for the pixel-aspect-ratio for us */
GST_DEBUG ("creating elements");
if (!create_element ("fakesrc", &src, &error) ||
if (!create_element ("appsrc", &src, &error) ||
!create_element ("ffmpegcolorspace", &csp, &error) ||
!create_element ("videoscale", &vscale, &error) ||
!create_element ("capsfilter", &filter1, &error) ||
!create_element ("capsfilter", &filter2, &error) ||
!create_element ("fakesink", &sink, &error))
!create_element ("appsink", &sink, &error))
goto no_elements;
pipeline = gst_pipeline_new ("screenshot-pipeline");
@ -130,63 +104,53 @@ gst_play_frame_conv_convert (GstBuffer * buf, GstCaps * to_caps)
goto no_pipeline;
GST_DEBUG ("adding elements");
gst_bin_add_many (GST_BIN (pipeline), src, csp, filter1, vscale, filter2,
sink, NULL);
gst_bin_add_many (GST_BIN (pipeline), src, csp, vscale, sink, NULL);
g_signal_connect (src, "handoff", G_CALLBACK (feed_fakesrc), buf);
/* set to 'fixed' sizetype */
g_object_set (src, "sizemax", GST_BUFFER_SIZE (buf), "sizetype", 2,
"num-buffers", 1, "signal-handoffs", TRUE, NULL);
/* adding this superfluous capsfilter makes linking cheaper */
to_caps_no_par = gst_caps_copy (to_caps);
gst_structure_remove_field (gst_caps_get_structure (to_caps_no_par, 0),
"pixel-aspect-ratio");
g_object_set (filter1, "caps", to_caps_no_par, NULL);
gst_caps_unref (to_caps_no_par);
g_object_set (filter2, "caps", to_caps, NULL);
g_signal_connect (sink, "handoff", G_CALLBACK (save_result), &result);
g_object_set (sink, "preroll-queue-len", 1, "signal-handoffs", TRUE, NULL);
/* set caps */
g_object_set (src, "caps", from_caps, NULL);
g_object_set (sink, "caps", to_caps, NULL);
/* FIXME: linking is still way too expensive, profile this properly */
GST_DEBUG ("linking src->csp");
if (!gst_element_link_pads (src, "src", csp, "sink"))
return NULL;
goto link_failed;
GST_DEBUG ("linking csp->filter1");
if (!gst_element_link_pads (csp, "src", filter1, "sink"))
return NULL;
GST_DEBUG ("linking csp->vscale");
if (!gst_element_link_pads (csp, "src", vscale, "sink"))
goto link_failed;
GST_DEBUG ("linking filter1->vscale");
if (!gst_element_link_pads (filter1, "src", vscale, "sink"))
return NULL;
GST_DEBUG ("linking vscale->sink");
if (!gst_element_link_pads (vscale, "src", sink, "sink"))
goto link_failed;
GST_DEBUG ("linking vscale->capsfilter");
if (!gst_element_link_pads (vscale, "src", filter2, "sink"))
return NULL;
/* now set the pipeline to the paused state, after we push the buffer into
* appsrc, this should preroll the converted buffer in appsink */
GST_DEBUG ("running conversion pipeline to caps %" GST_PTR_FORMAT, to_caps);
gst_element_set_state (pipeline, GST_STATE_PAUSED);
GST_DEBUG ("linking capsfilter->sink");
if (!gst_element_link_pads (filter2, "src", sink, "sink"))
return NULL;
GST_DEBUG ("running conversion pipeline");
gst_element_set_state (pipeline, GST_STATE_PLAYING);
/* feed buffer in appsrc */
GST_DEBUG ("feeding buffer %p, size %u, caps %" GST_PTR_FORMAT,
buf, GST_BUFFER_SIZE (buf), from_caps);
g_signal_emit_by_name (src, "push-buffer", buf, &ret);
/* now see what happens. We either got an error somewhere or the pipeline
* prerolled */
bus = gst_element_get_bus (pipeline);
msg =
gst_bus_poll (bus, GST_MESSAGE_ERROR | GST_MESSAGE_EOS, 25 * GST_SECOND);
gst_bus_poll (bus, GST_MESSAGE_ERROR | GST_MESSAGE_ASYNC_DONE,
25 * GST_SECOND);
if (msg) {
switch (GST_MESSAGE_TYPE (msg)) {
case GST_MESSAGE_EOS:{
case GST_MESSAGE_ASYNC_DONE:
{
/* we're prerolled, get the frame from appsink */
g_signal_emit_by_name (sink, "pull-preroll", &result);
if (result) {
GST_DEBUG ("conversion successful: result = %p", result);
} else {
GST_WARNING ("EOS but no result frame?!");
GST_WARNING ("prerolled but no result frame?!");
}
break;
}
@ -202,7 +166,6 @@ gst_play_frame_conv_convert (GstBuffer * buf, GstCaps * to_caps)
g_warning ("Could not take screenshot (and NULL error!)");
}
g_free (dbg);
result = NULL;
break;
}
default:{
@ -212,10 +175,10 @@ gst_play_frame_conv_convert (GstBuffer * buf, GstCaps * to_caps)
gst_message_unref (msg);
} else {
g_warning ("Could not take screenshot: %s", "timeout during conversion");
result = NULL;
}
gst_element_set_state (pipeline, GST_STATE_NULL);
gst_object_unref (bus);
gst_object_unref (pipeline);
return result;
@ -232,4 +195,10 @@ no_pipeline:
g_warning ("Could not take screenshot: %s", "no pipeline (unknown error)");
return NULL;
}
link_failed:
{
g_warning ("Could not take screenshot: %s", "failed to link elements");
gst_object_unref (pipeline);
return NULL;
}
}