Hi,
did you get my other reply? After two days of trial and error, I managed
to make a (statically) registered plugin, that works in a pipeline
without warnings or errors (attached). It doesn't do anything useful,
though.
Please let me know if you are making any progress with your sink.
alberto
On Sat, 2009-01-17 at 23:16 +0200, [email protected] wrote:
> hello, I want to make gentral gstreamer v4l2 sink, and prefer to make
> it with vala to bypass all gobject stuff, is it possible now? and if
> possible can you point me where to start?
>
--
Alberto Colombo, MSc
PhD student at Digital Imaging Research Centre
Kingston University, London
e-mail: [email protected]
phone: +44 (0)20 8547 8642
http://cism.kingston.ac.uk/people/details.php?AuthorID=925
This email has been scanned for all viruses by the MessageLabs Email
Security System.
using Gst, GLib;
// compile with:
// valac --pkg gstreamer-0.10 --pkg gstreamer-video-0.10 gst-app.vala
class Gstapp : GLib.Object
{
MainLoop loop = new MainLoop(null, false);
Bin pipeline;
Bin decoder;
Element sink;
Element filter;
/** reacts to messages from the pipeline bus */
private bool bus_watch(Bus bus, Message message)
{
//stdout.printf("Got %s message", Message.type_get_name(message.type));
switch (message.type)
{
case MessageType.ERROR:
{
Error err;
string debug;
message.parse_error(out err, out debug);
stdout.printf("Error: %s\n", err.message);
loop.quit();
break;
}
case MessageType.EOS:
{
loop.quit();
break;
}
default: break;
}
//stdout.putc('\n');
return true;
}
/** called by decodebin when a new pad is created */
private void on_new_pad(Pad pad)
{
Pad sinkpad = sink.get_pad("sink");
if (pad.can_link(sinkpad)) pad.link(sinkpad);
}
/** the main method */
public int run(string[] args)
{
Gst.init(ref args);
if (args.length != 2)
{
stdout.printf("usage: %s FILE\n", args[0]);
return 1;
}
bool plugin_registered = Plugin.register_static(
VERSION_MAJOR, VERSION_MINOR, "my-plugin-name", "description of it", plugin_init, "0.1",
"GPL", "source", "package name", "http://mywebsite.nil";);
assert(plugin_registered);
filter = ElementFactory.make("MyAdvancedTransform", "filter");
assert(filter != null);
assert(filter.name == "filter");
string location = args[1];
pipeline = new Pipeline("pipeline");
decoder = (Bin)ElementFactory.make("decodebin", "decoder");
Signal.connect_swapped(decoder, "new-decoded-pad", (Callback)on_new_pad, this);
dynamic Element source = ElementFactory.make("filesrc", "source");
source.location = location;
sink = ElementFactory.make("autovideosink", "sink");
var colorspace = ElementFactory.make("ffmpegcolorspace", "colorspace");
pipeline.add_many(source, decoder, colorspace, sink);
pipeline.add(filter);
source.link(decoder);
filter.link(colorspace);
colorspace.link(sink);
sink = filter;
pipeline.get_bus().add_watch(bus_watch);
pipeline.set_state(State.PLAYING);
loop.run();
pipeline.set_state(State.NULL);
return 0;
}
public static int main(string[] args)
{
var app = new Gstapp();
return app.run(args);
}
}
/**
Class that inherits from Basetransform. It should be easier to implement than
subclassing Element, but still doesn't work.
*/
class MyAdvancedTransform : VideoFilter
{
static const ElementDetails details = {
"MyAdvancedTransform",
"Example/SecondExample",
"Try to make a plugin using Vala",
"alberto <[email protected]>"
};
static StaticPadTemplate sink_factory;
static StaticPadTemplate src_factory;
class construct
{
sink_factory.name_template = "sink";
sink_factory.direction = PadDirection.SINK;
sink_factory.presence = PadPresence.ALWAYS;
sink_factory.static_caps.str = "ANY";
src_factory.name_template = "src";
src_factory.direction = PadDirection.SRC;
src_factory.presence = PadPresence.ALWAYS;
src_factory.static_caps.str = "ANY";
add_pad_template(src_facto...@get());
add_pad_template(sink_facto...@get());
set_details(details);
}
public override Gst.FlowReturn transform_ip(Buffer buf)
{
GLib.debug("Data is flowing!");
return Gst.FlowReturn.OK;
}
}
bool plugin_init(Plugin p)
{
bool res = true;
res &= Element.register(p, "MyAdvancedTransform", Rank.NONE, typeof(MyAdvancedTransform));
return res;
}
/*
I have removed the following bits of code to minimise clutter.
They may be reintroduced in the appropriate sections later, if at all.
// from bus callback
case MessageType.TAG:
{
TagList taglist;
message.parse_tag(out taglist);
// generates a warning in the C sources
taglist.foreach( (list, tag) => {
string val, niceval;
if (list.get_string(tag, out val))
niceval = " = \""+val+"\"";
else
niceval = "";
stdout.printf(": %s%s", tag, niceval);
});
break;
}
case MessageType.ELEMENT:
{
Structure s = message.get_structure();
// generates a warning in the C sources
s.foreach( (field_id, val) => {
stdout.printf("\tfield %s\n", field_id.to_string());
return true;
});
break;
}
case MessageType.STATE_CHANGED:
{
State oldstate, newstate, pending;
message.parse_state_changed(out oldstate, out newstate, out pending);
stdout.printf(": %d -> %d (%d)", (int)oldstate, (int)newstate, (int)pending);
break;
}
// MUST be static, otherwise valac will silently omit them in the C sources...
static string? vfs_location;
static string? rtsp_location;
static string? file_location;
const OptionEntry[] entries = {
{"vfs", 'v', 0, OptionArg.STRING, out vfs_location,
"play video from URI", "URI"},
{"rtsp", 'r', 0, OptionArg.STRING, out rtsp_location,
"play RTSP stream", "RTSP"},
{"file", 'f', 0, OptionArg.FILENAME, out file_location,
"play video from FILE", "FILE"},
{null}
};
OptionContext ctx = new OptionContext(" -- play video from file or RTSP");
OptionGroup gstgroup = Gst.init_get_option_group();
ctx.add_main_entries(entries, null);
ctx.add_group(#gstgroup);
Element source;
try
{
GLib.Object src;
ctx.parse(ref args);
if (rtsp_location != null)
{
src = ElementFactory.make("rtspsrc", "source");
src.set("location", rtsp_location);
}
else if (vfs_location != null)
{
src = ElementFactory.make("gnomevfssrc", "source");
src.set("location", vfs_location);
}
else if (file_location != null)
{
src = ElementFactory.make("filesrc", "source");
src.set("location", file_location);
}
else
{
stdout.printf("%s", ctx.get_help(true, null));
throw new OptionError.FAILED("please specify a file/uri to play");
}
assert(src != null);
source = (Element)src;
}
catch (OptionError e)
{
stdout.printf("Error: %s\n\n", e.message);
return 1;
}
*/
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