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/* Copyright 2011-2014 Yorba Foundation
*
* This is a Vala-rewrite of GStreamer snapshot example. Adapted from earlier
* work from Wim Taymans.
*
* This software is licensed under the GNU LGPL (version 2.1 or later).
* See the COPYING file in this distribution.
*/
// Shotwell Thumbnailer takes in a video file and returns a thumbnail to stdout. This is
// a replacement for totem-video-thumbnailer
class ShotwellThumbnailer {
const string caps_string = """video/x-raw,format=RGB,pixel-aspect-ratio=1/1""";
public static int main(string[] args) {
Gst.Element pipeline, sink;
int width, height;
Gst.Sample sample;
string descr;
Gdk.Pixbuf pixbuf;
int64 duration, position;
Gst.StateChangeReturn ret;
bool res;
Gst.init(ref args);
if (args.length != 2) {
stdout.printf("usage: %s [filename]\n Writes video thumbnail to stdout\n", args[0]);
return 1;
}
descr = "filesrc location=\"%s\" ! decodebin ! videoconvert ! videoscale ! ".printf(args[1]) +
"appsink name=sink caps=\"%s\"".printf(caps_string);
try {
// Create new pipeline.
pipeline = Gst.parse_launch(descr);
// Get sink.
sink = ((Gst.Bin) pipeline).get_by_name("sink");
// Set to PAUSED to make the first frame arrive in the sink.
ret = pipeline.set_state(Gst.State.PAUSED);
if (ret == Gst.StateChangeReturn.FAILURE) {
stderr.printf("Failed to play the file: couldn't set state\n");
return 3;
} else if (ret == Gst.StateChangeReturn.NO_PREROLL) {
stderr.printf("Live sources not supported yet.\n");
return 4;
}
// This can block for up to 5 seconds. If your machine is really overloaded,
// it might time out before the pipeline prerolled and we generate an error. A
// better way is to run a mainloop and catch errors there.
ret = pipeline.get_state(null, null, 5 * Gst.SECOND);
if (ret == Gst.StateChangeReturn.FAILURE) {
stderr.printf("Failed to play the file: couldn't get state.\n");
return 3;
}
/* get the duration */
pipeline.query_duration (Gst.Format.TIME, out duration);
position = 1 * Gst.SECOND;
/* seek to the a position in the file. Most files have a black first frame so
* by seeking to somewhere else we have a bigger chance of getting something
* more interesting. An optimisation would be to detect black images and then
* seek a little more */
pipeline.seek_simple (Gst.Format.TIME, Gst.SeekFlags.KEY_UNIT | Gst.SeekFlags.FLUSH, position);
/* get the preroll buffer from appsink, this block untils appsink really
* prerolls */
GLib.Signal.emit_by_name (sink, "pull-preroll", out sample, null);
// if we have a buffer now, convert it to a pixbuf. It's possible that we
// don't have a buffer because we went EOS right away or had an error.
if (sample != null) {
Gst.Buffer buffer;
Gst.Caps caps;
unowned Gst.Structure s;
Gst.MapInfo mapinfo;
uint8[]? pngdata;
// Get the snapshot buffer format now. We set the caps on the appsink so
// that it can only be an rgb buffer. The only thing we have not specified
// on the caps is the height, which is dependent on the pixel-aspect-ratio
// of the source material.
caps = sample.get_caps();
if (caps == null) {
stderr.printf("could not get snapshot format\n");
return 5;
}
s = caps.get_structure(0);
// We need to get the final caps on the buffer to get the size.
res = s.get_int("width", out width);
res |= s.get_int("height", out height);
if (!res) {
stderr.printf("Could not get snapshot dimension\n");
return 6;
}
buffer = sample.get_buffer();
buffer.map(out mapinfo, Gst.MapFlags.READ);
// Create pixmap from buffer and save, gstreamer video buffers have a stride
// that is rounded up to the nearest multiple of 4.
pixbuf = new Gdk.Pixbuf.from_data(mapinfo.data, Gdk.Colorspace.RGB, false, 8,
width, height, (((width * 3)+3)&~3), null);
// Save the pixbuf.
pixbuf.save_to_buffer(out pngdata, "png");
stdout.write(pngdata);
buffer.unmap(mapinfo);
} else {
stderr.printf("Could not make snapshot\n");
return 10;
}
// cleanup and exit.
pipeline.set_state(Gst.State.NULL);
} catch (Error e) {
stderr.printf(e.message);
return 2;
}
return 0;
}
}
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