[Spice-devel] [PATCH v4] channel-display-gst: Use h/w based decoders with Intel GPUs if possible (v4)

Vivek Kasireddy vivek.kasireddy at intel.com
Tue Oct 17 07:25:49 UTC 2023


We first try to detect if an Intel GPU is available (by looking into
udev's database) and then probe Gstreamer's registry cache to see
if there is h/w based decoder (element) available for the incoming
video codec format. If both these conditions are satisfied (i.e,
Intel Media SDK Gstreamer plugin (libgstmsdk.so) and associated
libraries are properly installed), we then create a simple decode
pipeline using appropriate h/w based decoder and post-processor
elements instead of relying on playbin -- which may not be able to
auto-select these elements.

For example, if the incoming codec format is h264, we then create
a pipeline using msdkh264dec and vaapipostproc elements instead of
avdec_h264 and videoconvert.

v2: (addressed some review comments from Frediano)
- s/gboolean/bool, s/TRUE/true, s/FALSE/false
- Used a single cleanup label instead of multiple while instantiating
  elements
- Moved the code that launches the Gst pipeline into a helper that
  is used while trying h/w based plugins

v3:
- Updated the patch to reflect the new signature and return value of
  spice_udev_detect_gpu().

v4:
- Include the string "_hw_" in the function that finds best h/w plugins
- Change type and determine plugins array length using G_N_ELEMENTS
- Free vpp_name immediately after using it to prevent leak
- Rebase on master

Cc: Frediano Ziglio <freddy77 at gmail.com>
Cc: Gerd Hoffmann <kraxel at redhat.com>
Cc: Marc-André Lureau <marcandre.lureau at redhat.com>
Cc: Dongwon Kim <dongwon.kim at intel.com>
Signed-off-by: Vivek Kasireddy <vivek.kasireddy at intel.com>
Signed-off-by: Hazwan Arif Mazlan <hazwan.arif.mazlan at intel.com>
Signed-off-by: Jin Chung Teng <jin.chung.teng at intel.com>
---
 src/channel-display-gst.c | 217 ++++++++++++++++++++++++++++++++++----
 1 file changed, 195 insertions(+), 22 deletions(-)

diff --git a/src/channel-display-gst.c b/src/channel-display-gst.c
index 5c9927b..de606b5 100644
--- a/src/channel-display-gst.c
+++ b/src/channel-display-gst.c
@@ -20,6 +20,7 @@
 #include "spice-common.h"
 #include "spice-channel-priv.h"
 #include "common/recorder.h"
+#include "common/udev.h"
 
 #include "channel-display-priv.h"
 
@@ -489,13 +490,205 @@ deep_element_added_cb(GstBin *pipeline, GstBin *bin, GstElement *element,
     }
 }
 
-static gboolean create_pipeline(SpiceGstDecoder *decoder)
+static gchar *find_best_hw_plugin(const gchar *dec_name)
+{
+    static const char plugins[][8] = {"msdk", "va", "vaapi"};
+    GstRegistry *registry;
+    GstPluginFeature *feature;
+    gchar *feature_name;
+    int i;
+
+    registry = gst_registry_get();
+    if (!registry) {
+        return NULL;
+    }
+
+    for (i = 0; i < G_N_ELEMENTS(plugins); i++) {
+        feature_name = !dec_name ? g_strconcat(plugins[i], "postproc", NULL) :
+                       g_strconcat(plugins[i], dec_name, "dec", NULL);
+        feature = gst_registry_lookup_feature(registry, feature_name);
+        if (!feature) {
+            g_free(feature_name);
+            feature_name = NULL;
+            continue;
+        }
+        gst_object_unref(feature);
+        break;
+    }
+    return feature_name;
+}
+
+static bool launch_pipeline(SpiceGstDecoder *decoder)
 {
     GstBus *bus;
+
+    if (decoder->appsink) {
+        GstAppSinkCallbacks appsink_cbs = { NULL };
+        appsink_cbs.new_sample = new_sample;
+        gst_app_sink_set_callbacks(decoder->appsink, &appsink_cbs, decoder, NULL);
+        gst_app_sink_set_max_buffers(decoder->appsink, MAX_DECODED_FRAMES);
+        gst_app_sink_set_drop(decoder->appsink, FALSE);
+    }
+    bus = gst_pipeline_get_bus(GST_PIPELINE(decoder->pipeline));
+    gst_bus_add_watch(bus, handle_pipeline_message, decoder);
+    gst_object_unref(bus);
+
+    decoder->clock = gst_pipeline_get_clock(GST_PIPELINE(decoder->pipeline));
+
+    if (gst_element_set_state(decoder->pipeline, GST_STATE_PLAYING) == GST_STATE_CHANGE_FAILURE) {
+        SPICE_DEBUG("GStreamer error: Unable to set the pipeline to the playing state.");
+        free_pipeline(decoder);
+        return false;
+    }
+
+    return true;
+}
+
+static bool try_intel_hw_pipeline(SpiceGstDecoder *decoder)
+{
+    GstElement *pipeline = NULL, *src = NULL, *sink = NULL;
+    GstElement *parser = NULL, *hw_decoder = NULL, *vpp = NULL;
+    GstCaps *src_caps, *sink_caps;
+    int codec_type = decoder->base.codec_type;
+    const gchar *dec_name = gst_opts[codec_type].name;
+    gchar *hw_dec_name, *vpp_name, *parser_name;
+    gboolean use_parser;
+
+    use_parser = codec_type == SPICE_VIDEO_CODEC_TYPE_H264 ||
+                 codec_type == SPICE_VIDEO_CODEC_TYPE_H265;
+
+    src = gst_element_factory_make("appsrc", NULL);
+    if (!src) {
+        spice_warning("error upon creation of 'appsrc' element");
+        return false;
+    }
+    sink = gst_element_factory_make("appsink", NULL);
+    if (!sink) {
+        spice_warning("error upon creation of 'appsink' element");
+        goto err;
+    }
+
+    if (use_parser) {
+        parser_name = g_strconcat(dec_name, "parse", NULL);
+        parser = gst_element_factory_make(parser_name, NULL);
+        g_free(parser_name);
+        if (!parser) {
+            spice_warning("error upon creation of 'parser' element");
+            goto err;
+        }
+    }
+
+    hw_dec_name = find_best_hw_plugin(dec_name);
+    if (!hw_dec_name) {
+        spice_warning("error finding suitable plugin for decode");
+        goto err;
+    }
+    hw_decoder = gst_element_factory_make(hw_dec_name, NULL);
+    g_free(hw_dec_name);
+    if (!hw_decoder) {
+        spice_warning("error upon creation of 'decoder' element");
+        goto err;
+    }
+    vpp_name = find_best_hw_plugin(NULL);
+    if (!vpp_name) {
+        spice_warning("error finding suitable plugin for postproc");
+        goto err;
+    }
+    vpp = gst_element_factory_make(vpp_name, NULL);
+    g_free(vpp_name);
+    if (!vpp) {
+        spice_warning("error upon creation of 'vpp' element");
+        goto err;
+    }
+    g_object_set(vpp,
+                 "format", GST_VIDEO_FORMAT_BGRx,
+                 NULL);
+
+    pipeline = gst_pipeline_new(NULL);
+    if (!pipeline) {
+        spice_warning("error upon creation of 'pipeline' element");
+        goto err;
+    }
+
+    src_caps = gst_caps_from_string(gst_opts[codec_type].dec_caps);
+    g_object_set(src,
+                 "caps", src_caps,
+                 "is-live", TRUE,
+                 "format", GST_FORMAT_TIME,
+                 "max-bytes", G_GINT64_CONSTANT(0),
+                 "block", TRUE,
+                 NULL);
+    gst_caps_unref(src_caps);
+    decoder->appsrc = GST_APP_SRC(gst_object_ref(src));
+
+    sink_caps = gst_caps_from_string("video/x-raw,format=BGRx");
+    g_object_set(sink,
+                 "caps", sink_caps,
+                 "sync", FALSE,
+                 "drop", FALSE,
+                 NULL);
+    gst_caps_unref(sink_caps);
+    decoder->appsink = GST_APP_SINK(sink);
+
+    if (hand_pipeline_to_widget(decoder->base.stream,
+        GST_PIPELINE(pipeline))) {
+        spice_warning("error handing pipeline to widget");
+        goto err;
+    }
+
+    if (use_parser) {
+        gst_bin_add_many(GST_BIN(pipeline), src, parser, hw_decoder,
+                         vpp, sink, NULL);
+        if (!gst_element_link_many(src, parser, hw_decoder, vpp,
+                                   sink, NULL)) {
+            spice_warning("error linking elements");
+            goto err;
+        }
+    } else {
+        gst_bin_add_many(GST_BIN(pipeline), src, hw_decoder,
+                         vpp, sink, NULL);
+        if (!gst_element_link_many(src, hw_decoder, vpp, sink, NULL)) {
+            spice_warning("error linking elements");
+            goto err;
+        }
+    }
+
+    decoder->pipeline = pipeline;
+    return launch_pipeline(decoder);
+
+err:
+    if (src) {
+        gst_object_unref(src);
+    }
+    if (sink) {
+        gst_object_unref(sink);
+    }
+    if (use_parser) {
+        gst_object_unref(parser);
+    }
+    if (hw_decoder) {
+        gst_object_unref(hw_decoder);
+    }
+    if (vpp) {
+        gst_object_unref(vpp);
+    }
+    return false;
+}
+
+static gboolean create_pipeline(SpiceGstDecoder *decoder)
+{
     GstElement *playbin, *sink;
     SpiceGstPlayFlags flags;
     GstCaps *caps;
     static bool playbin3_supported = true;
+    GpuVendor vendor = spice_udev_detect_gpu(INTEL_VENDOR_ID);
+
+    if (vendor == VENDOR_GPU_DETECTED ||
+        vendor == VENDOR_GPU_UNKNOWN) {
+        if (try_intel_hw_pipeline(decoder)) {
+            return TRUE;
+        }
+    }
 
     playbin = playbin3_supported ?
               gst_element_factory_make("playbin3", "playbin") : NULL;
@@ -571,29 +764,9 @@ static gboolean create_pipeline(SpiceGstDecoder *decoder)
     g_warn_if_fail(decoder->appsrc == NULL);
     decoder->pipeline = playbin;
 
-    if (decoder->appsink) {
-        GstAppSinkCallbacks appsink_cbs = { NULL };
-        appsink_cbs.new_sample = new_sample;
-        gst_app_sink_set_callbacks(decoder->appsink, &appsink_cbs, decoder, NULL);
-        gst_app_sink_set_max_buffers(decoder->appsink, MAX_DECODED_FRAMES);
-        gst_app_sink_set_drop(decoder->appsink, FALSE);
-    }
-    bus = gst_pipeline_get_bus(GST_PIPELINE(decoder->pipeline));
-    gst_bus_add_watch(bus, handle_pipeline_message, decoder);
-    gst_object_unref(bus);
-
-    decoder->clock = gst_pipeline_get_clock(GST_PIPELINE(decoder->pipeline));
-
-    if (gst_element_set_state(decoder->pipeline, GST_STATE_PLAYING) == GST_STATE_CHANGE_FAILURE) {
-        SPICE_DEBUG("GStreamer error: Unable to set the pipeline to the playing state.");
-        free_pipeline(decoder);
-        return FALSE;
-    }
-
-    return TRUE;
+    return launch_pipeline(decoder);
 }
 
-
 /* ---------- VideoDecoder's public API ---------- */
 
 static void spice_gst_decoder_reschedule(VideoDecoder *video_decoder)
-- 
2.39.2



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