examples: Add test code to verify decoder caps update

Sample command lines
* Configures pipeline with video encoder
decoder-caps-update \
  --encoder="video/x-raw,format=NV12 ! qsvh264enc" \
  --decoder=d3d11h264dec \
  --videosink=d3d11videosink

* Playing exisiting file
decoder-caps-update \
  --location=test_file.mp4 \
  --decoder=d3d11h264dec \
  --videosink=d3d11videosink

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/3328>

subprojects/gst-plugins-bad/tests/examples/codecs/decoder-caps-update.cpp

@@ -0,0 +1,324 @@
+/* GStreamer
+ * Copyright (C) 2022 Seungha Yang <seungha@centricular.com>
+ *
+ * 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.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <gst/gst.h>
+#include <gst/video/video.h>
+#include <stdlib.h>
+#include <string>
+#include <mutex>
+#include "../key-handler.h"
+
+static GMainLoop *loop = nullptr;
+static std::mutex input_lock;
+static gint par = 1;
+static gint fps = 30;
+static gboolean set_hdr10 = FALSE;
+static GstElement *setter = nullptr;
+static gboolean updated = FALSE;
+
+static void
+print_keyboard_help (void)
+{
+  static struct
+  {
+    const gchar *key_desc;
+    const gchar *key_help;
+  } key_controls[] = {
+    {
+    "q", "Quit"}, {
+    "right arrow", "Increase framerate"}, {
+    "left arrow", "Decrease framerate"}, {
+    "up arrow", "Increase pixel-aspect-ratio"}, {
+    "down arrow", "Decrease pixel-aspect-ratio"}, {
+    "m", "Toggle HDR10 metadata"}, {
+    "k", "show keyboard shortcuts"}
+  };
+
+  guint i, chars_to_pad, desc_len, max_desc_len = 0;
+
+  gst_print ("\n\n%s\n\n", "Keyboard controls:");
+
+  for (i = 0; i < G_N_ELEMENTS (key_controls); ++i) {
+    desc_len = g_utf8_strlen (key_controls[i].key_desc, -1);
+    max_desc_len = MAX (max_desc_len, desc_len);
+  }
+  ++max_desc_len;
+
+  for (i = 0; i < G_N_ELEMENTS (key_controls); ++i) {
+    chars_to_pad = max_desc_len - g_utf8_strlen (key_controls[i].key_desc, -1);
+    gst_print ("\t%s", key_controls[i].key_desc);
+    gst_print ("%-*s: ", chars_to_pad, "");
+    gst_print ("%s\n", key_controls[i].key_help);
+  }
+  gst_print ("\n");
+}
+
+static void
+keyboard_cb (gchar input, gboolean is_ascii, gpointer user_data)
+{
+  std::lock_guard<std::mutex> lk (input_lock);
+
+  if (!is_ascii) {
+    switch (input) {
+      case KB_ARROW_UP:
+        par++;
+        updated = TRUE;
+        gst_println ("Increasing pixel-aspect-ratio to %d", par);
+        break;
+      case KB_ARROW_DOWN:
+        if (par == 1)
+          return;
+        par--;
+        updated = TRUE;
+        gst_println ("Decreasing pixel-aspect-ratio to %d", par);
+        break;
+      case KB_ARROW_RIGHT:
+        fps++;
+        updated = TRUE;
+        gst_println ("Increasing framerate to %d", fps);
+        break;
+      case KB_ARROW_LEFT:
+        if (fps == 1)
+          return;
+        fps--;
+        updated = TRUE;
+        gst_println ("Decreasing framerate to %d", fps);
+        break;
+      default:
+        break;
+    }
+  } else {
+    switch (input) {
+      case 'k':
+      case 'K':
+        print_keyboard_help ();
+        break;
+      case 'q':
+      case 'Q':
+        g_main_loop_quit (loop);
+        break;
+      case 'm':
+      case 'M':
+        set_hdr10 = !set_hdr10;
+        updated = TRUE;
+        gst_println ("%sable HDR10 metadata", set_hdr10 ? "En" : "Dis");
+        break;
+      default:
+        break;
+    }
+  }
+
+  if (updated && setter) {
+    GstPad *pad = gst_element_get_static_pad (setter, "sink");
+    GstCaps *caps = gst_pad_get_current_caps (pad);
+    gst_object_unref (pad);
+
+    if (!caps)
+      return;
+
+    if (gst_caps_is_any (caps) || gst_caps_is_empty (caps)) {
+      gst_caps_unref (caps);
+      return;
+    }
+
+    caps = gst_caps_make_writable (caps);
+    gst_caps_set_simple (caps, "pixel-aspect-ratio", GST_TYPE_FRACTION,
+        par, 1, "framerate", GST_TYPE_FRACTION, fps, 1, nullptr);
+
+    if (set_hdr10) {
+      gst_caps_set_simple (caps, "mastering-display-info", G_TYPE_STRING,
+          "34000:16000:13250:34500:7500:3000:15635:16450:10000000:1",
+          "content-light-level", G_TYPE_STRING, "1000:400", nullptr);
+    }
+
+    g_object_set (setter, "caps", caps, nullptr);
+    gst_caps_unref (caps);
+  }
+}
+
+static void
+decoder_caps_notify (GstPad * pad, GParamSpec * pspec, gpointer user_data)
+{
+  GstCaps *caps;
+  gchar *caps_str;
+
+  g_object_get (pad, "caps", &caps, nullptr);
+  if (!caps)
+    return;
+
+  caps_str = gst_caps_to_string (caps);
+  gst_println ("\nDecoder output caps\n%s\n", caps_str);
+
+  g_free (caps_str);
+  gst_caps_unref (caps);
+}
+
+static gboolean
+bus_msg (GstBus * bus, GstMessage * msg, gpointer user_data)
+{
+  switch (GST_MESSAGE_TYPE (msg)) {
+    case GST_MESSAGE_ERROR:{
+      GError *err;
+      gchar *dbg;
+
+      gst_message_parse_error (msg, &err, &dbg);
+      gst_printerrln ("ERROR %s", err->message);
+      if (dbg != NULL)
+        gst_printerrln ("ERROR debug information: %s", dbg);
+      g_clear_error (&err);
+      g_free (dbg);
+
+      g_main_loop_quit (loop);
+      break;
+    }
+    case GST_MESSAGE_EOS:
+      gst_println ("Got EOS");
+      g_main_loop_quit (loop);
+      break;
+    default:
+      break;
+  }
+
+  return TRUE;
+}
+
+gint
+main (gint argc, gchar ** argv)
+{
+  GstElement *pipeline;
+  GError *error = nullptr;
+  GOptionContext *option_ctx;
+  gchar *decoder_name = nullptr;
+  gchar *encoder_name = nullptr;
+  gchar *sink_name = nullptr;
+  gchar *location = nullptr;
+  GOptionEntry options[] = {
+    {"decoder", 0, 0, G_OPTION_ARG_STRING, &decoder_name,
+        "Video decoder to use"},
+    {"encoder", 0, 0, G_OPTION_ARG_STRING, &encoder_name,
+        "Video encoder description. Ignored if \"location\" is set "
+        "(example: \"x264enc speed-preset=ultrafast\""},
+    {"videosink", 0, 0, G_OPTION_ARG_STRING, &sink_name,
+        "Video sink to use"},
+    {"location", 0, 0, G_OPTION_ARG_STRING, &location, "File location"},
+    {nullptr}
+  };
+
+  option_ctx =
+      g_option_context_new ("Video decoder caps update example");
+  g_option_context_add_main_entries (option_ctx, options, nullptr);
+  g_option_context_set_help_enabled (option_ctx, TRUE);
+  if (!g_option_context_parse (option_ctx, &argc, &argv, &error)) {
+    gst_printerrln ("option parsing failed: %s\n", error->message);
+    g_clear_error (&error);
+    exit (1);
+  }
+
+  g_option_context_free (option_ctx);
+  gst_init (nullptr, nullptr);
+
+  if (!decoder_name) {
+    gst_printerrln ("Decoder must be specified");
+    exit (1);
+  }
+
+  if (!encoder_name && !location) {
+    gst_printerrln ("Encoder or file location must be specified");
+    exit (1);
+  }
+
+  std::string pipeline_desc;
+  if (location) {
+    pipeline_desc = "filesrc location=" + std::string (location)
+      + " ! parsebin ! capssetter name=setter ! "
+      + std::string (decoder_name) + " name=dec";
+  } else {
+    pipeline_desc = "videotestsrc ! " + std::string (encoder_name)
+      + " ! parsebin ! capssetter name=setter ! "
+      + std::string (decoder_name) + " name=dec";
+  }
+
+  if (sink_name) {
+    pipeline_desc += " ! " + std::string (sink_name);
+  } else {
+    pipeline_desc += " ! fakevideosink";
+  }
+
+  gst_println ("Constructing test pipeline \"%s\"", pipeline_desc.c_str());
+
+  loop = g_main_loop_new (nullptr, FALSE);
+  pipeline = gst_parse_launch (pipeline_desc.c_str(), &error);
+  if (error) {
+    gst_printerrln ("Could not construct pipeline, error: %s",
+        error->message);
+    exit(1);
+  }
+
+  setter = gst_bin_get_by_name (GST_BIN (pipeline), "setter");
+  if (!setter) {
+    gst_printerrln ("Could not get capssetter from pipeline");
+    exit(1);
+  }
+
+  GstElement *dec = gst_bin_get_by_name (GST_BIN (pipeline), "dec");
+  if (!dec) {
+    gst_printerrln ("Could not get decoder from pipeline");
+    exit(1);
+  }
+
+  GstPad *pad = gst_element_get_static_pad (dec, "src");
+  g_signal_connect (pad, "notify::caps", G_CALLBACK (decoder_caps_notify),
+      nullptr);
+  gst_object_unref (pad);
+  gst_object_unref (dec);
+
+  gst_bus_add_watch (GST_ELEMENT_BUS (pipeline), bus_msg, nullptr);
+
+  /* run the pipeline */
+  GstStateChangeReturn ret =
+      gst_element_set_state (pipeline, GST_STATE_PLAYING);
+  if (ret == GST_STATE_CHANGE_FAILURE) {
+    gst_printerrln ("Pipeline doesn't want to playing");
+  } else {
+    set_key_handler ((KeyInputCallback) keyboard_cb, nullptr);
+    gst_println ("Press k to see supported keyboard inputs");
+    g_main_loop_run (loop);
+    unset_key_handler ();
+  }
+
+  input_lock.lock();
+  gst_clear_object (&setter);
+  input_lock.unlock();
+
+  gst_element_set_state (pipeline, GST_STATE_NULL);
+  gst_bus_remove_watch (GST_ELEMENT_BUS (pipeline));
+
+  gst_object_unref (pipeline);
+  g_main_loop_unref (loop);
+
+  g_free (decoder_name);
+  g_free (encoder_name);
+  g_free (location);
+
+  return 0;
+}

subprojects/gst-plugins-bad/tests/examples/codecs/meson.build

@@ -0,0 +1,10 @@
+if host_system not in ['windows', 'linux']
+  subdir_done()
+endif
+
+executable('decoder-caps-update',
+  ['decoder-caps-update.cpp', '../key-handler.c'],
+  include_directories : [configinc],
+  dependencies: [gst_dep, gstbase_dep, gstvideo_dep],
+  c_args : gst_plugins_bad_args,
+  install: false)

subprojects/gst-plugins-bad/tests/examples/meson.build

@@ -2,6 +2,7 @@ subdir('audiomixmatrix')
 subdir('avsamplesink')
 subdir('camerabin2')
 subdir('codecparsers')
+subdir('codecs')
 subdir('d3d11')
 subdir('directfb')
 subdir('gtk')