encoders: add quality level tuning

This patch adds the handling of VAEncMiscParameterTypeQualityLevel,
in gstreamer-vaapi encoders:

  The encoding quality could be set through this structure, if the
  implementation supports multiple quality levels. The quality level set
  through this structure is persistent over the entire coded sequence, or
  until a new structure is being sent. The quality level range can be queried
  through the VAConfigAttribEncQualityRange attribute. A lower value means
  higher quality, and a value of 1 represents the highest quality. The quality
  level setting is used as a trade-off between quality and speed/power
  consumption, with higher quality corresponds to lower speed and higher power
  consumption.

The quality level is set by the element's parameter "quality-level" with a
hard-coded range of 1 to 8.

Later, when the encoder is configured in run time, just before start
processing, the quality level is scaled to the codec range. If
VAConfigAttribEncQualityRange is not available in the used VA backend, then
the quality level is set to zero, which means "disabled".

All the available codecs now process this parameter if it is available.

https://bugzilla.gnome.org/show_bug.cgi?id=778733

Signed-off-by: Víctor Manuel Jáquez Leal <vjaquez@igalia.com>

1 files changed, 17 insertions, 0 deletions

diff --git a/gst-libs/gst/vaapi/gstvaapiencoder_priv.h b/gst-libs/gst/vaapi/gstvaapiencoder_priv.h
index 5cf748a7..a80ba76f 100644
--- a/gst-libs/gst/vaapi/gstvaapiencoder_priv.h
+++ b/gst-libs/gst/vaapi/gstvaapiencoder_priv.h
@@ -164,6 +164,17 @@ G_BEGIN_DECLS
 #define GST_VAAPI_ENCODER_TUNE(encoder) \
   (GST_VAAPI_ENCODER_CAST (encoder)->tune)
 
+/**
+ * GST_VAAPI_ENCODER_QUALITY_LEVEL:
+ * @encoder: a #GstVaapiEncoder
+ *
+ * Macro that evaluates to the quality level
+ * This is an internal macro that does not do any run-time type check.
+ */
+#undef  GST_VAAPI_ENCODER_QUALITY_LEVEL
+#define GST_VAAPI_ENCODER_QUALITY_LEVEL(encoder) \
+  (GST_VAAPI_ENCODER_CAST (encoder)->quality_level)
+
 /* Generate a mask for the supplied tuning option (internal) */
 #define GST_VAAPI_ENCODER_TUNE_MASK(TUNE) \
   (1U << G_PASTE (GST_VAAPI_ENCODER_TUNE_, TUNE))
@@ -216,6 +227,7 @@ struct _GstVaapiEncoder
   guint32 rate_control_mask;
   guint bitrate; /* kbps */
   guint keyframe_period;
+  guint quality_level;
 
   GMutex mutex;
   GCond surface_free;
@@ -340,6 +352,11 @@ gst_vaapi_encoder_release_surface (GstVaapiEncoder * encoder,
   gst_vaapi_surface_proxy_unref (proxy);
 }
 
+G_GNUC_INTERNAL
+gboolean
+gst_vaapi_encoder_ensure_param_quality_level (GstVaapiEncoder * encoder,
+    GstVaapiEncPicture * picture);
+
 G_END_DECLS
 
 #endif /* GST_VAAPI_ENCODER_PRIV_H */