--- /dev/null
+/* Small helper element for format conversion
+ * Copyright (C) 2005 Tim-Philipp Müller <tim centricular net>
+ * Copyright (C) 2010 Brandon Lewis <brandon.lewis@collabora.co.uk>
+ * Copyright (C) 2010 Edward Hervey <edward.hervey@collabora.co.uk>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#include <string.h>
+#include "video.h"
+
+static gboolean
+caps_are_raw (const GstCaps * caps)
+{
+ guint i, len;
+
+ len = gst_caps_get_size (caps);
+
+ for (i = 0; i < len; i++) {
+ GstStructure *st = gst_caps_get_structure (caps, i);
+ if (gst_structure_has_name (st, "video/x-raw-yuv") ||
+ gst_structure_has_name (st, "video/x-raw-rgb"))
+ return TRUE;
+ }
+
+ return FALSE;
+}
+
+static gboolean
+create_element (const gchar * factory_name, GstElement ** element,
+ GError ** err)
+{
+ *element = gst_element_factory_make (factory_name, NULL);
+ if (*element)
+ return TRUE;
+
+ if (err && *err == NULL) {
+ *err = g_error_new (GST_CORE_ERROR, GST_CORE_ERROR_MISSING_PLUGIN,
+ "cannot create element '%s' - please check your GStreamer installation",
+ factory_name);
+ }
+
+ return FALSE;
+}
+
+static GstElement *
+get_encoder (const GstCaps * caps, GError ** err)
+{
+ GList *encoders = NULL;
+ GList *filtered = NULL;
+ GstElementFactory *factory = NULL;
+ GstElement *encoder = NULL;
+
+ encoders =
+ gst_element_factory_list_get_elements (GST_ELEMENT_FACTORY_TYPE_ENCODER |
+ GST_ELEMENT_FACTORY_TYPE_MEDIA_IMAGE, GST_RANK_NONE);
+
+ if (encoders == NULL) {
+ *err = g_error_new (GST_CORE_ERROR, GST_CORE_ERROR_MISSING_PLUGIN,
+ "Cannot find any image encoder");
+ goto fail;
+ }
+
+ GST_INFO ("got factory list %p", encoders);
+ gst_plugin_feature_list_debug (encoders);
+
+ filtered =
+ gst_element_factory_list_filter (encoders, caps, GST_PAD_SRC, FALSE);
+ GST_INFO ("got filtered list %p", filtered);
+
+ if (filtered == NULL) {
+ gchar *tmp = gst_caps_to_string (caps);
+ *err = g_error_new (GST_CORE_ERROR, GST_CORE_ERROR_MISSING_PLUGIN,
+ "Cannot find any image encoder for caps %s", tmp);
+ g_free (tmp);
+ goto fail;
+ }
+
+ gst_plugin_feature_list_debug (filtered);
+
+ factory = (GstElementFactory *) filtered->data;
+
+ GST_INFO ("got factory %p", factory);
+ encoder = gst_element_factory_create (factory, NULL);
+
+ GST_INFO ("created encoder element %p, %s", encoder,
+ gst_element_get_name (encoder));
+
+fail:
+ if (encoders)
+ gst_plugin_feature_list_free (encoders);
+ if (filtered)
+ gst_plugin_feature_list_free (filtered);
+
+ return encoder;
+}
+
+/**
+ * gst_video_convert_frame:
+ * @buf: a #GstBuffer
+ * @to_caps: the #GstCaps to convert to
+ * @timeout: the maximum amount of time allowed for the processing.
+ * @err: pointer to a #GError. Can be %NULL.
+ *
+ * Converts a raw video buffer into the specified output caps.
+ *
+ * The output caps can be any raw video formats or any image formats (jpeg, png, ...).
+ *
+ * The width, height and pixel-aspect-ratio can also be specified in the output caps.
+ *
+ * Returns: The converted #GstBuffer, or %NULL if an error happened (in which case @err
+ * will point to the #GError).
+ */
+GstBuffer *
+gst_video_convert_frame (GstBuffer * buf, const GstCaps * to_caps,
+ GstClockTime timeout, GError ** err)
+{
+ GstElement *src = NULL, *csp = NULL, *vscale = NULL, *sink = NULL, *encoder =
+ NULL, *pipeline;
+ GstMessage *msg;
+ GstBuffer *result = NULL;
+ GError *error = NULL;
+ GstBus *bus;
+ GstCaps *from_caps;
+ GstFlowReturn ret;
+
+ g_return_val_if_fail (buf != NULL, NULL);
+ g_return_val_if_fail (to_caps != NULL, NULL);
+ g_return_val_if_fail (GST_BUFFER_CAPS (buf) != NULL, NULL);
+
+ from_caps = GST_BUFFER_CAPS (buf);
+
+ /* videoscale is here to correct for the pixel-aspect-ratio for us */
+ GST_DEBUG ("creating elements");
+ if (!create_element ("appsrc", &src, &error) ||
+ !create_element ("ffmpegcolorspace", &csp, &error) ||
+ !create_element ("videoscale", &vscale, &error) ||
+ !create_element ("appsink", &sink, &error))
+ goto no_elements;
+
+ pipeline = gst_pipeline_new ("videoconvert-pipeline");
+ if (pipeline == NULL)
+ goto no_pipeline;
+
+ /* Add black borders if necessary to keep the DAR */
+ g_object_set (vscale, "add-borders", TRUE, NULL);
+
+ GST_DEBUG ("adding elements");
+ gst_bin_add_many (GST_BIN (pipeline), src, csp, vscale, sink, 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"))
+ goto link_failed;
+
+ GST_DEBUG ("linking csp->vscale");
+ if (!gst_element_link_pads (csp, "src", vscale, "sink"))
+ goto link_failed;
+
+ if (caps_are_raw (to_caps)) {
+ GST_DEBUG ("linking vscale->sink");
+
+ if (!gst_element_link_pads (vscale, "src", sink, "sink"))
+ goto link_failed;
+ } else {
+ encoder = get_encoder (to_caps, &error);
+ if (!encoder)
+ goto no_encoder;
+ gst_bin_add (GST_BIN (pipeline), encoder);
+
+ GST_DEBUG ("linking vscale->encoder");
+ if (!gst_element_link (vscale, encoder))
+ goto link_failed;
+
+ GST_DEBUG ("linking encoder->sink");
+ if (!gst_element_link_pads (encoder, "src", sink, "sink"))
+ goto link_failed;
+ }
+
+ /* 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);
+
+ /* 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_timed_pop_filtered (bus,
+ timeout, GST_MESSAGE_ERROR | GST_MESSAGE_ASYNC_DONE);
+
+ if (msg) {
+ switch (GST_MESSAGE_TYPE (msg)) {
+ 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_ERROR ("prerolled but no result frame?!");
+ }
+ break;
+ }
+ case GST_MESSAGE_ERROR:{
+ gchar *dbg = NULL;
+
+ gst_message_parse_error (msg, &error, &dbg);
+ if (error) {
+ GST_ERROR ("Could not convert video frame: %s", error->message);
+ GST_DEBUG ("%s [debug: %s]", error->message, GST_STR_NULL (dbg));
+ if (err)
+ *err = error;
+ else
+ g_error_free (error);
+ }
+ g_free (dbg);
+ break;
+ }
+ default:{
+ g_return_val_if_reached (NULL);
+ }
+ }
+ gst_message_unref (msg);
+ } else {
+ GST_ERROR ("Could not convert video frame: timeout during conversion");
+ if (err)
+ *err = g_error_new (GST_CORE_ERROR, GST_CORE_ERROR_FAILED,
+ "Could not convert video frame: timeout during conversion");
+ }
+
+ gst_element_set_state (pipeline, GST_STATE_NULL);
+ gst_object_unref (bus);
+ gst_object_unref (pipeline);
+
+ return result;
+
+ /* ERRORS */
+no_encoder:
+ {
+ GST_ERROR ("could not find an encoder for provided caps");
+ if (err)
+ *err = error;
+ else
+ g_error_free (error);
+ return NULL;
+ }
+no_elements:
+ {
+ if (src)
+ gst_object_unref (src);
+ if (csp)
+ gst_object_unref (csp);
+ if (vscale)
+ gst_object_unref (vscale);
+ if (sink)
+ gst_object_unref (sink);
+ GST_ERROR ("Could not convert video frame: %s", error->message);
+ if (err)
+ *err = error;
+ else
+ g_error_free (error);
+ return NULL;
+ }
+no_pipeline:
+ {
+ GST_ERROR ("Could not convert video frame: no pipeline (unknown error)");
+ if (err)
+ *err = g_error_new (GST_CORE_ERROR, GST_CORE_ERROR_FAILED,
+ "Could not convert video frame: no pipeline (unknown error)");
+ return NULL;
+ }
+link_failed:
+ {
+ GST_ERROR ("Could not convert video frame: failed to link elements");
+ if (err)
+ *err = g_error_new (GST_CORE_ERROR, GST_CORE_ERROR_NEGOTIATION,
+ "Could not convert video frame: failed to link elements");
+ gst_object_unref (pipeline);
+ return NULL;
+ }
+}