git.maemo.org Git - mafwsubrenderer/blob - mafw-gst-subtitles-renderer/libmafw-gst-renderer/gstscreenshot.c

   1 /* Small helper element for format conversion
   2  * (c) 2004 Ronald Bultje <rbultje@ronald.bitfreak.net>
   3  * Portion Copyright © 2009 Nokia Corporation and/or its
   4  * subsidiary(-ies).* All rights reserved. *
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Library General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Library General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Library General Public
  17  * License along with this library; if not, write to the
  18  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19  * Boston, MA 02111-1307, USA.
  20  */
  21
  22 #ifdef HAVE_CONFIG_H
  23 #include "config.h"
  24 #endif
  25
  26 #include <gst/gst.h>
  27 #include <string.h>
  28
  29 #include "gstscreenshot.h"
  30
  31 typedef struct {
  32         GstBuffer *result;
  33         GstElement *src;
  34         GstElement *sink;
  35         GstElement *pipeline;
  36         BvwFrameConvCb cb;
  37         gpointer cb_data;
  38 } GstScreenshotData;
  39
  40 /* GST_DEBUG_CATEGORY_EXTERN (_totem_gst_debug_cat); */
  41 /* #define GST_CAT_DEFAULT _totem_gst_debug_cat */
  42
  43 static void feed_fakesrc(GstElement *src, GstBuffer *buf, GstPad *pad,
  44                          gpointer data)
  45 {
  46         GstBuffer *in_buf = GST_BUFFER(data);
  47
  48         g_assert(GST_BUFFER_SIZE(buf) >= GST_BUFFER_SIZE(in_buf));
  49         g_assert(!GST_BUFFER_FLAG_IS_SET(buf, GST_BUFFER_FLAG_READONLY));
  50
  51         gst_buffer_set_caps(buf, GST_BUFFER_CAPS(in_buf));
  52
  53         memcpy(GST_BUFFER_DATA(buf), GST_BUFFER_DATA(in_buf),
  54                GST_BUFFER_SIZE(in_buf));
  55
  56         GST_BUFFER_SIZE(buf) = GST_BUFFER_SIZE(in_buf);
  57
  58         GST_DEBUG("feeding buffer %p, size %u, caps %" GST_PTR_FORMAT,
  59                   buf, GST_BUFFER_SIZE(buf), GST_BUFFER_CAPS(buf));
  60
  61         gst_buffer_unref(in_buf);
  62 }
  63
  64 static void save_result(GstElement *sink, GstBuffer *buf, GstPad *pad,
  65                         gpointer data)
  66 {
  67         GstScreenshotData *gsd = data;
  68
  69         gsd->result = gst_buffer_ref(buf);
  70
  71         GST_DEBUG("received converted buffer %p with caps %" GST_PTR_FORMAT,
  72                   gsd->result, GST_BUFFER_CAPS(gsd->result));
  73 }
  74
  75 static gboolean create_element(const gchar *factory_name, GstElement **element,
  76                                GError **err)
  77 {
  78         *element = gst_element_factory_make(factory_name, NULL);
  79         if (*element)
  80                 return TRUE;
  81
  82         if (err && *err == NULL) {
  83                 *err = g_error_new(
  84                         GST_CORE_ERROR, GST_CORE_ERROR_MISSING_PLUGIN,
  85                         "cannot create element '%s' - please check your "
  86                         "GStreamer installation", factory_name);
  87         }
  88
  89         return FALSE;
  90 }
  91
  92 static gboolean finalize_process(GstScreenshotData *gsd)
  93 {
  94         g_signal_handlers_disconnect_matched(gsd->sink, (GSignalMatchType)
  95                                              G_SIGNAL_MATCH_FUNC, 0, 0, NULL,
  96                                              save_result, NULL);
  97         g_signal_handlers_disconnect_matched(gsd->src, (GSignalMatchType)
  98                                              G_SIGNAL_MATCH_FUNC, 0, 0, NULL,
  99                                              feed_fakesrc, NULL);
 100         gst_element_set_state(gsd->pipeline, GST_STATE_NULL);
 101
 102         g_free(gsd);
 103
 104         return FALSE;
 105 }
 106
 107 static gboolean async_bus_handler(GstBus *bus, GstMessage *msg,
 108                                   gpointer data)
 109 {
 110         GstScreenshotData *gsd = data;
 111         gboolean keep_watch = TRUE;
 112
 113         switch (GST_MESSAGE_TYPE(msg)) {
 114         case GST_MESSAGE_EOS: {
 115                 if (gsd->result != NULL) {
 116                         GST_DEBUG("conversion successful: result = %p",
 117                                   gsd->result);
 118                 } else {
 119                         GST_WARNING("EOS but no result frame?!");
 120                 }
 121                 gsd->cb(gsd->result, gsd->cb_data);
 122                 keep_watch = finalize_process(gsd);
 123                 break;
 124         }
 125         case GST_MESSAGE_ERROR: {
 126                 gchar *dbg = NULL;
 127                 GError *error = NULL;
 128
 129                 gst_message_parse_error(msg, &error, &dbg);
 130                 if (error != NULL) {
 131                         g_warning("Could not take screenshot: %s",
 132                                   error->message);
 133                         GST_DEBUG("%s [debug: %s]", error->message,
 134                                   GST_STR_NULL(dbg));
 135                         g_error_free(error);
 136                 } else {
 137                         g_warning("Could not take screenshot(and "
 138                                   "NULL error!)");
 139                 }
 140                 g_free(dbg);
 141                 gsd->result = NULL;
 142                 gsd->cb(gsd->result, gsd->cb_data);
 143                 keep_watch = finalize_process(gsd);
 144                 break;
 145         }
 146         default:
 147                 break;
 148         }
 149
 150         return keep_watch;
 151 }
 152
 153 /* takes ownership of the input buffer */
 154 gboolean bvw_frame_conv_convert(GstBuffer *buf, GstCaps *to_caps,
 155                                 BvwFrameConvCb cb, gpointer cb_data)
 156 {
 157         static GstElement *src = NULL, *sink = NULL, *pipeline = NULL,
 158                 *filter1 = NULL, *filter2 = NULL;
 159         static GstBus *bus;
 160         GError *error = NULL;
 161         GstCaps *to_caps_no_par;
 162         GstScreenshotData *gsd;
 163
 164         g_return_val_if_fail(GST_BUFFER_CAPS(buf) != NULL, FALSE);
 165         g_return_val_if_fail(cb != NULL, FALSE);
 166
 167         if (pipeline == NULL) {
 168                 GstElement *csp, *vscale;
 169
 170                 pipeline = gst_pipeline_new("screenshot-pipeline");
 171                 if(pipeline == NULL) {
 172                         g_warning("Could not take screenshot: "
 173                                   "no pipeline (unknown error)");
 174                         return FALSE;
 175                 }
 176
 177                 /* videoscale is here to correct for the
 178                  * pixel-aspect-ratio for us */
 179                 GST_DEBUG("creating elements");
 180                 if(!create_element("fakesrc", &src, &error) ||
 181                    !create_element("ffmpegcolorspace", &csp, &error) ||
 182                    !create_element("videoscale", &vscale, &error) ||
 183                    !create_element("capsfilter", &filter1, &error) ||
 184                    !create_element("capsfilter", &filter2, &error) ||
 185                    !create_element("fakesink", &sink, &error)) {
 186                         g_warning("Could not take screenshot: %s",
 187                                   error->message);
 188                         g_error_free(error);
 189                         return FALSE;
 190                 }
 191
 192                 GST_DEBUG("adding elements");
 193                 gst_bin_add_many(GST_BIN(pipeline), src, csp, filter1, vscale,
 194                                  filter2, sink, NULL);
 195
 196                 g_object_set(sink, "preroll-queue-len", 1,
 197                              "signal-handoffs", TRUE, NULL);
 198
 199                 /* set to 'fixed' sizetype */
 200                 g_object_set(src, "sizetype", 2, "num-buffers", 1,
 201                              "signal-handoffs", TRUE, NULL);
 202
 203                 /* FIXME: linking is still way too expensive, profile
 204                  * this properly */
 205                 GST_DEBUG("linking src->csp");
 206                 if(!gst_element_link_pads(src, "src", csp, "sink"))
 207                         return FALSE;
 208
 209                 GST_DEBUG("linking csp->filter1");
 210                 if(!gst_element_link_pads(csp, "src", filter1, "sink"))
 211                         return FALSE;
 212
 213                 GST_DEBUG("linking filter1->vscale");
 214                 if(!gst_element_link_pads(filter1, "src", vscale, "sink"))
 215                         return FALSE;
 216
 217                 GST_DEBUG("linking vscale->capsfilter");
 218                 if(!gst_element_link_pads(vscale, "src", filter2, "sink"))
 219                         return FALSE;
 220
 221                 GST_DEBUG("linking capsfilter->sink");
 222                 if(!gst_element_link_pads(filter2, "src", sink, "sink"))
 223                         return FALSE;
 224
 225                 bus = gst_element_get_bus(pipeline);
 226         }
 227
 228         /* adding this superfluous capsfilter makes linking cheaper */
 229         to_caps_no_par = gst_caps_copy(to_caps);
 230         gst_structure_remove_field(gst_caps_get_structure(to_caps_no_par, 0),
 231                                    "pixel-aspect-ratio");
 232         g_object_set(filter1, "caps", to_caps_no_par, NULL);
 233         gst_caps_unref(to_caps_no_par);
 234
 235         g_object_set(filter2, "caps", to_caps, NULL);
 236         gst_caps_unref(to_caps);
 237
 238         gsd = g_new0(GstScreenshotData, 1);
 239
 240         gsd->src = src;
 241         gsd->sink = sink;
 242         gsd->pipeline = pipeline;
 243         gsd->cb = cb;
 244         gsd->cb_data = cb_data;
 245
 246         g_signal_connect(sink, "handoff", G_CALLBACK(save_result), gsd);
 247
 248         g_signal_connect(src, "handoff", G_CALLBACK(feed_fakesrc), buf);
 249
 250         gst_bus_add_watch(bus, async_bus_handler, gsd);
 251
 252         /* set to 'fixed' sizetype */
 253         g_object_set(src, "sizemax", GST_BUFFER_SIZE(buf), NULL);
 254
 255         GST_DEBUG("running conversion pipeline");
 256         gst_element_set_state(pipeline, GST_STATE_PLAYING);
 257
 258         return TRUE;
 259 }