[Spice-devel] [PATCH 2/2] gstreamer-encoder: Use a h/w based encoder with Intel GPUs if possible (v2)

[Frediano Ziglio]

Il giorno ven 15 set 2023 alle ore 01:33 Vivek Kasireddy
<vivek.kasireddy at intel.com> ha scritto:
>
> Once it is determined that an Intel GPU is available/active (after
> looking into udev's database), we try to see if there is a h/w
> based encoder (element) available (in Gstreamer's registry cache)
> for the user selected video codec. In other words, if we find that
> the Intel Media SDK Gstreamer plugin (libgstmsdk.so) and associated
> libraries (such as va or vaapi) are all installed properly, we add
> the appropriate h/w based encoder and post-processor/converter
> elements to the pipeline (along with any relevant options) instead
> of the s/w based elements.
>
> For example, if the user selects h264 as the preferred codec format,
> msdkh264enc and vapostproc will be preferred instead of x264enc
> and videoconvert.
>
> v2: (addressed some review comments from Frediano)
> - Moved the udev helper into spice-common
> - Refactored the code to choose plugins in order msdk > va > vaapi
>
> 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>
> Co-developed-by: Jin Chung Teng <jin.chung.teng at intel.com>
> Co-developed-by: Hazwan Arif Mazlan <hazwan.arif.mazlan at intel.com>
> ---
>  server/gstreamer-encoder.c | 96 ++++++++++++++++++++++++++++++++++++--
>  1 file changed, 93 insertions(+), 3 deletions(-)
>
> diff --git a/server/gstreamer-encoder.c b/server/gstreamer-encoder.c
> index 057509b5..44666f42 100644
> --- a/server/gstreamer-encoder.c
> +++ b/server/gstreamer-encoder.c
> @@ -31,6 +31,7 @@
>  #include "red-common.h"
>  #include "video-encoder.h"
>  #include "utils.h"
> +#include "common/udev.h"
>
>
>  #define SPICE_GST_DEFAULT_FPS 30
> @@ -913,14 +914,94 @@ static const gchar* get_gst_codec_name(const SpiceGstEncoder *encoder)
>      }
>  }
>
> +static const char video_codecs[][8] = {
> +    { "" },
> +    { "mjpeg" },
> +    { "vp8" },
> +    { "h264" },
> +    { "vp9" },
> +    { "h265" },
> +};
> +
> +static bool gst_features_lookup(const gchar *feature_name)
> +{
> +    GstRegistry *registry;
> +    GstPluginFeature *feature;
> +
> +    registry = gst_registry_get();
> +    if (!registry) {
> +        return false;
> +    }
> +
> +    feature = gst_registry_lookup_feature(registry, feature_name);
> +    if (!feature) {
> +        return false;
> +    }
> +
> +    gst_object_unref(feature);
> +    return true;
> +}
> +
> +static gchar *find_best_plugin(const gchar *codec_name)
> +{
> +    const char *plugins[3] = {"msdk", "va", "vaapi"};
> +    gchar *feature_name;
> +    int i;
> +
> +    for (i = 0; i < 3; i++) {
> +        feature_name = !codec_name ? g_strconcat(plugins[i], "postproc", NULL) :

The name for the msdk postproc is msdkvpp, not msdkpostproc.
Looking at this function and the next one it looks correct to use,
let's say an encoder from msdk (like msdkvp9enc) and the vaapi post
processor (like vaapipostproc), but it seems wrong to me.

> +                       g_strconcat(plugins[i], codec_name, "enc", NULL);
> +        if (!gst_features_lookup(feature_name)) {
> +            g_free(feature_name);
> +            feature_name = NULL;
> +            continue;
> +        }
> +        break;
> +    }
> +    return feature_name;
> +}
> +
> +static void try_intel_hw_plugins(const gchar *codec_name, gchar **converter,
> +                                 gchar **gstenc_name, gchar **gstenc_opts)
> +{
> +    gchar *encoder = find_best_plugin(codec_name);
> +    if (!encoder) {
> +        return;
> +    }
> +    gchar *vpp = find_best_plugin(NULL);
> +    if (!vpp) {
> +        return;
> +    }
> +
> +    g_free(*converter);
> +    g_free(*gstenc_name);
> +    g_free(*gstenc_opts);
> +
> +    *gstenc_name = encoder;
> +    if (strstr(encoder, "msdk")) {
> +        *gstenc_opts = g_strdup("async-depth=1 rate-control=3 gop-size=1 tune=16 b-frames=0 target-usage=7 min-qp=15 max-qp=35");

These options are nice for h264 (and probably h265) but are wrong for
vp9 and probably mjpeg.

> +    } else if (strstr(encoder, "vaapi")) {
> +        *gstenc_opts = g_strdup("rate-control=cqp max-bframes=0 min-qp=15 max-qp=35");
> +    } else {
> +        *gstenc_opts = g_strdup("rate-control=16 b-frames=0 target-usage=7 min-qp=15 max-qp=35");
> +    }

Similar comment for these.

> +
> +    if (strstr(vpp, "vaapi")) {
> +        *converter = g_strconcat(vpp, " ! video/x-raw(memory:VASurface),format=NV12", NULL);
> +    } else {
> +        *converter = g_strconcat(vpp, " ! video/x-raw(memory:VAMemory),format=NV12", NULL);
> +    }

>From gst-inspect msdkvpp does not support any of these. Is this expected?

> +    g_free(vpp);
> +}
> +
>  static gboolean create_pipeline(SpiceGstEncoder *encoder)
>  {
>  #ifdef HAVE_GSTREAMER_0_10
> -    const gchar *converter = "ffmpegcolorspace";
> +    gchar *converter = g_strdup("ffmpegcolorspace");
>  #else
> -    const gchar *converter = "videoconvert ! video/x-raw,format=NV12";
> +    gchar *converter = g_strdup("videoconvert ! video/x-raw,format=NV12");
>  #endif
> -    const gchar* gstenc_name = get_gst_codec_name(encoder);
> +    gchar* gstenc_name = g_strdup(get_gst_codec_name(encoder));
>      if (!gstenc_name) {
>          return FALSE;
>      }
> @@ -973,12 +1054,21 @@ static gboolean create_pipeline(SpiceGstEncoder *encoder)
>          return FALSE;
>      }
>
> +    const char *codec_name = video_codecs[encoder->base.codec_type];
> +    GpuVendor vendor = spice_udev_detect_gpu();
> +    if (vendor == GPU_VENDOR_INTEL) {
> +        try_intel_hw_plugins(codec_name, &converter, &gstenc_name,
> +                             &gstenc_opts);
> +    }
> +
>      GError *err = NULL;
>      gchar *desc = g_strdup_printf("appsrc is-live=true format=time do-timestamp=true name=src !"
>                                    " %s ! %s name=encoder %s ! appsink name=sink",
>                                    converter, gstenc_name, gstenc_opts);
>      spice_debug("GStreamer pipeline: %s", desc);
>      encoder->pipeline = gst_parse_launch_full(desc, NULL, GST_PARSE_FLAG_FATAL_ERRORS, &err);
> +    g_free(converter);
> +    g_free(gstenc_name);
>      g_free(gstenc_opts);
>      g_free(desc);
>      if (!encoder->pipeline || err) {

Frediano