gstreamer/gst-libs/gst/basecamerabinsrc/gstcamerabinpreview.c
Tim-Philipp Müller d4caa1b3ae camerabinpreview: fix potential crash on preview pipeline error
Post error message on actual element, not the allocated helper struct.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/1474>
2020-07-28 13:14:24 +00:00

409 lines
12 KiB
C

/*
* GStreamer
* Copyright (C) 2008 Nokia Corporation <multimedia@maemo.org>
*
* 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., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
/**
* SECTION:camerabingeneral
* @short_description: helper functions for #GstCameraBin and it's modules
*
* Common helper functions for #GstCameraBin.
*
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <gst/app/gstappsrc.h>
#include <gst/app/gstappsink.h>
#include <gst/glib-compat-private.h>
#include "gstcamerabinpreview.h"
#include "gstbasecamerasrc.h"
GST_DEBUG_CATEGORY_EXTERN (base_camera_src_debug);
#define GST_CAT_DEFAULT base_camera_src_debug
static void _gst_camerabin_preview_set_caps (GstCameraBinPreviewPipelineData *
preview, GstCaps * caps);
static gboolean
bus_callback (GstBus * bus, GstMessage * message, gpointer user_data)
{
switch (GST_MESSAGE_TYPE (message)) {
case GST_MESSAGE_ERROR:{
GError *err;
GstCameraBinPreviewPipelineData *data;
data = user_data;
gst_message_parse_error (message, &err, NULL);
GST_WARNING ("Error from preview pipeline: %s", err->message);
g_error_free (err);
/* TODO Not sure if we should post an Error or Warning here */
GST_ELEMENT_ERROR (data->element, CORE, FAILED,
("fatal error in preview pipeline, disposing the pipeline"), (NULL));
/* Possible error situations:
* 1) cond_wait pending. prevent deadlock by signalling the cond
* 2) preview_pipeline_post called with new buffer to handle. returns
* because data->pipeline is set to null
* 3) new preview caps incoming. returns because data->pipeline is null
*/
if (data->pipeline) {
gst_element_set_state (data->pipeline, GST_STATE_NULL);
gst_object_unref (data->pipeline);
data->pipeline = NULL;
}
g_cond_signal (&data->processing_cond);
break;
}
default:
break;
}
return TRUE;
}
static GstFlowReturn
gst_camerabin_preview_pipeline_new_sample (GstAppSink * appsink,
gpointer user_data)
{
GstSample *sample;
GstStructure *s;
GstMessage *msg;
GstCameraBinPreviewPipelineData *data;
data = user_data;
sample = gst_app_sink_pull_sample (appsink);
s = gst_structure_new (GST_BASE_CAMERA_SRC_PREVIEW_MESSAGE_NAME,
"sample", GST_TYPE_SAMPLE, sample, NULL);
gst_sample_unref (sample);
msg = gst_message_new_element (GST_OBJECT (data->element), s);
GST_DEBUG_OBJECT (data->element, "sending message with preview image");
if (gst_element_post_message (data->element, msg) == FALSE) {
GST_WARNING_OBJECT (data->element,
"This element has no bus, therefore no message sent!");
}
g_mutex_lock (&data->processing_lock);
data->processing--;
if (data->processing == 0)
g_cond_signal (&data->processing_cond);
g_mutex_unlock (&data->processing_lock);
return GST_FLOW_OK;
}
/**
* gst_camerabin_create_preview_pipeline:
* @element: Owner of this pipeline
* @filter: Custom filter to process preview data (an extra ref is taken)
*
* Creates a new previewing pipeline that can receive buffers
* to be posted as camerabin preview messages for @element
*
* Returns: The newly created #GstCameraBinPreviewPipelineData
*/
GstCameraBinPreviewPipelineData *
gst_camerabin_create_preview_pipeline (GstElement * element,
GstElement * filter)
{
GstCameraBinPreviewPipelineData *data;
GstElement *csp;
GstElement *vscale;
gboolean added = FALSE;
gboolean linkfail = FALSE;
GstBus *bus;
GstAppSinkCallbacks callbacks = { 0, };
data = g_new0 (GstCameraBinPreviewPipelineData, 1);
data->pipeline = gst_pipeline_new ("preview-pipeline");
data->appsrc = gst_element_factory_make ("appsrc", "preview-appsrc");
data->appsink = gst_element_factory_make ("appsink", "preview-appsink");
csp = gst_element_factory_make ("videoconvert", "preview-vconv");
vscale = gst_element_factory_make ("videoscale", "preview-vscale");
if (!data->appsrc || !data->appsink || !csp || !vscale) {
goto error;
}
g_object_set (data->appsrc, "emit-signals", FALSE, NULL);
g_object_set (data->appsink, "sync", FALSE, "enable-last-sample",
FALSE, NULL);
gst_bin_add_many (GST_BIN (data->pipeline), data->appsrc,
data->appsink, csp, vscale, NULL);
if (filter)
gst_bin_add (GST_BIN (data->pipeline), gst_object_ref (filter));
added = TRUE;
if (filter) {
linkfail |=
GST_PAD_LINK_FAILED (gst_element_link_pads_full (data->appsrc, "src",
filter, NULL, GST_PAD_LINK_CHECK_NOTHING));
linkfail |=
GST_PAD_LINK_FAILED (gst_element_link_pads_full (filter, NULL,
vscale, "sink", GST_PAD_LINK_CHECK_CAPS));
} else {
linkfail |=
GST_PAD_LINK_FAILED (gst_element_link_pads_full (data->appsrc, "src",
vscale, "sink", GST_PAD_LINK_CHECK_NOTHING));
}
linkfail |=
GST_PAD_LINK_FAILED (gst_element_link_pads_full (vscale, "src", csp,
"sink", GST_PAD_LINK_CHECK_NOTHING));
linkfail |=
GST_PAD_LINK_FAILED (gst_element_link_pads_full (csp, "src",
data->appsink, "sink", GST_PAD_LINK_CHECK_NOTHING));
if (linkfail) {
GST_WARNING ("Failed to link preview pipeline elements");
goto error;
}
callbacks.new_sample = gst_camerabin_preview_pipeline_new_sample;
gst_app_sink_set_callbacks ((GstAppSink *) data->appsink, &callbacks, data,
NULL);
bus = gst_pipeline_get_bus (GST_PIPELINE (data->pipeline));
gst_bus_add_watch (bus, bus_callback, data);
gst_object_unref (bus);
data->element = element;
data->filter = filter;
data->vscale = vscale;
g_mutex_init (&data->processing_lock);
g_cond_init (&data->processing_cond);
data->pending_preview_caps = NULL;
data->processing = 0;
return data;
error:
GST_WARNING ("Failed to create camerabin's preview pipeline");
if (!added) {
if (csp)
gst_object_unref (csp);
if (vscale)
gst_object_unref (vscale);
if (data->appsrc)
gst_object_unref (data->appsrc);
if (data->appsink)
gst_object_unref (data->appsink);
}
gst_camerabin_destroy_preview_pipeline (data);
return NULL;
}
/**
* gst_camerabin_destroy_preview_pipeline:
* @preview: the #GstCameraBinPreviewPipelineData
*
* Frees a #GstCameraBinPreviewPipelineData
*/
void
gst_camerabin_destroy_preview_pipeline (GstCameraBinPreviewPipelineData *
preview)
{
g_return_if_fail (preview != NULL);
g_mutex_clear (&preview->processing_lock);
g_cond_clear (&preview->processing_cond);
if (preview->pipeline) {
GstBus *bus;
gst_element_set_state (preview->pipeline, GST_STATE_NULL);
bus = gst_pipeline_get_bus (GST_PIPELINE (preview->pipeline));
gst_bus_remove_watch (bus);
gst_object_unref (bus);
gst_object_unref (preview->pipeline);
}
g_free (preview);
}
/**
* gst_camerabin_preview_pipeline_post:
* @preview: the #GstCameraBinPreviewPipelineData
* @sample: the sample to be posted as a preview
*
* Converts the @sample to the desired format and posts the preview
* message to the bus.
*
* Returns: %TRUE on success
*/
gboolean
gst_camerabin_preview_pipeline_post (GstCameraBinPreviewPipelineData * preview,
GstSample * sample)
{
g_return_val_if_fail (preview != NULL, FALSE);
g_return_val_if_fail (preview->pipeline != NULL, FALSE);
g_return_val_if_fail (sample, FALSE);
g_mutex_lock (&preview->processing_lock);
g_return_val_if_fail (preview->pipeline != NULL, FALSE);
if (preview->pending_preview_caps) {
if (preview->processing > 0) {
g_cond_wait (&preview->processing_cond, &preview->processing_lock);
}
_gst_camerabin_preview_set_caps (preview, preview->pending_preview_caps);
gst_caps_replace (&preview->pending_preview_caps, NULL);
}
preview->processing++;
g_object_set (preview->appsrc, "caps", gst_sample_get_caps (sample), NULL);
gst_app_src_push_buffer ((GstAppSrc *) preview->appsrc,
gst_buffer_ref (gst_sample_get_buffer (sample)));
g_mutex_unlock (&preview->processing_lock);
return TRUE;
}
static void
_gst_camerabin_preview_set_caps (GstCameraBinPreviewPipelineData * preview,
GstCaps * caps)
{
GstState state, pending;
GstStateChangeReturn ret;
g_return_if_fail (preview != NULL);
g_return_if_fail (preview->pipeline != NULL);
ret = gst_element_get_state (preview->pipeline, &state, &pending, 0);
if (ret == GST_STATE_CHANGE_FAILURE) {
/* make it try again */
state = GST_STATE_PLAYING;
pending = GST_STATE_VOID_PENDING;
}
gst_element_set_state (preview->pipeline, GST_STATE_NULL);
g_object_set (preview->appsink, "caps", caps, NULL);
if (pending != GST_STATE_VOID_PENDING)
state = pending;
gst_element_set_state (preview->pipeline, state);
}
/**
* gst_camerabin_preview_set_caps:
* @preview: the #GstCameraBinPreviewPipelineData
* @caps: the #GstCaps to be set (a new ref will be taken)
*
* The caps that preview buffers should have when posted
* on the bus
*/
void
gst_camerabin_preview_set_caps (GstCameraBinPreviewPipelineData * preview,
GstCaps * caps)
{
g_return_if_fail (preview != NULL);
g_mutex_lock (&preview->processing_lock);
if (preview->processing == 0) {
_gst_camerabin_preview_set_caps (preview, caps);
} else {
GST_DEBUG ("Preview pipeline busy, storing new caps as pending");
gst_caps_replace (&preview->pending_preview_caps, caps);
}
g_mutex_unlock (&preview->processing_lock);
}
/**
* gst_camerabin_preview_set_filter:
* @preview: the #GstCameraBinPreviewPipelineData
* @filter: Custom filter to process preview data (an extra ref is taken)
*
* Set the filter element into preview pipeline.
*
* Returns: %TRUE on success
*/
gboolean
gst_camerabin_preview_set_filter (GstCameraBinPreviewPipelineData * preview,
GstElement * filter)
{
gboolean ret = TRUE;
GstState current;
g_return_val_if_fail (preview != NULL, FALSE);
GST_DEBUG ("Preview pipeline setting new filter %p", filter);
g_mutex_lock (&preview->processing_lock);
gst_element_get_state (preview->pipeline, &current, NULL, 0);
if (preview->processing == 0 && current == GST_STATE_NULL) {
gboolean linkfail = FALSE;
if (preview->filter) {
/* Unlink and remove old filter */
gst_element_unlink (preview->appsrc, preview->filter);
gst_element_unlink (preview->filter, preview->vscale);
gst_bin_remove (GST_BIN (preview->pipeline), preview->filter);
} else {
/* Make room for filter by breaking the link between appsrc and vcale */
gst_element_unlink (preview->appsrc, preview->vscale);
}
if (filter) {
/* Add and link the new filter between appsrc and vscale */
gst_bin_add (GST_BIN (preview->pipeline), gst_object_ref (filter));
linkfail |=
GST_PAD_LINK_FAILED (gst_element_link_pads_full (preview->appsrc,
"src", filter, NULL, GST_PAD_LINK_CHECK_NOTHING));
linkfail |=
GST_PAD_LINK_FAILED (gst_element_link_pads_full (filter, NULL,
preview->vscale, "sink", GST_PAD_LINK_CHECK_CAPS));
} else {
/* No filter was given. Just link the appsrc to vscale directly */
linkfail |=
GST_PAD_LINK_FAILED (gst_element_link_pads_full (preview->appsrc,
"src", preview->vscale, "sink", GST_PAD_LINK_CHECK_NOTHING));
}
if (linkfail) {
GST_WARNING ("Linking the filter to pipeline failed");
ret = FALSE;
} else {
GST_DEBUG ("Linking the filter to pipeline successful");
preview->filter = filter;
}
} else {
GST_WARNING ("Cannot change filter when pipeline is running");
ret = FALSE;
}
g_mutex_unlock (&preview->processing_lock);
return ret;
}