Merge pull request #3370 from metalefty/x264-threads

make x264 threads configurable

docs/man/gfx.toml.5.in

@@ -68,7 +68,7 @@ for use with xrdp. Here are available options:
 
 .TP
 \fBprofile\fR = \fI<string>\fR
-Select a profile.  Here are available options:
+Select a profile. Here are available options:
 
 .B main, baseline, high, high10, high422, high444
 
@@ -83,12 +83,20 @@ Set the size of the VBV buffer size in kilobits.
 
 .TP
 \fBfps_num\fR = \fI<integer>\fR
-Set the fps numerator. 
+Set the fps numerator.
 
 .TP
 \fBfps_den\fR = \fI<integer>\fR
 Set the fps denominator.
 
+.TP
+\fBthreads = \fI<integer>\fR
+Specify how many CPU threads to use for H.264 encoding per screen (0 for
+auto). Carefully evaluate this value when configuring it to avoid exhausting
+the available threads. For example, if 3 users are connected simultaneously
+with dual screens, xrdp may use up to <threads> * 3 * 2 threads for H.264
+encoding. Please also note that too many threads can hurt quality.
+
 .SH "OPENH264"
 
 \fB[OpenH264]\fR section defines encoding parameters that will be passed to

tests/xrdp/gfx/gfx_codec_h264_only.toml

@@ -9,6 +9,7 @@ vbv_max_bitrate = 0
 vbv_buffer_size = 0
 fps_num = 24
 fps_den = 1
+threads = 1
 
 [x264.lan]
 [x264.wan]

tests/xrdp/gfx/gfx_codec_h264_preferred.toml

@@ -9,6 +9,7 @@ vbv_max_bitrate = 0
 vbv_buffer_size = 0
 fps_num = 24
 fps_den = 1
+threads = 1
 
 [x264.lan]
 [x264.wan]

tests/xrdp/gfx/gfx_codec_order_undefined.toml

@@ -9,6 +9,7 @@ vbv_max_bitrate = 0
 vbv_buffer_size = 0
 fps_num = 24
 fps_den = 1
+threads = 1
 
 [x264.lan]
 [x264.wan]

tests/xrdp/gfx/gfx_codec_rfx_only.toml

@@ -9,6 +9,7 @@ vbv_max_bitrate = 0
 vbv_buffer_size = 0
 fps_num = 24
 fps_den = 1
+threads = 1
 
 [x264.lan]
 [x264.wan]

tests/xrdp/gfx/gfx_codec_rfx_preferred.toml

@@ -9,6 +9,7 @@ vbv_max_bitrate = 0
 vbv_buffer_size = 0
 fps_num = 24
 fps_den = 1
+threads = 1
 
 [x264.lan]
 [x264.wan]

tests/xrdp/gfx/gfx_codec_rfx_preferred_odd.toml

@@ -9,6 +9,7 @@ vbv_max_bitrate = 0
 vbv_buffer_size = 0
 fps_num = 24
 fps_den = 1
+threads = 1
 
 [x264.lan]
 [x264.wan]

tests/xrdp/gfx/gfx_h264_encoder_invalid.toml

@@ -19,6 +19,7 @@ vbv_max_bitrate = 0
 vbv_buffer_size = 0
 fps_num = 60
 fps_den = 1
+threads = 1
 
 [x264.lan]
 # inherits default

tests/xrdp/gfx/gfx_h264_encoder_openh264.toml

@@ -19,6 +19,7 @@ vbv_max_bitrate = 0
 vbv_buffer_size = 0
 fps_num = 60
 fps_den = 1
+threads = 1
 
 [x264.lan]
 # inherits default

tests/xrdp/gfx/gfx_h264_encoder_undefined.toml

@@ -19,6 +19,7 @@ vbv_max_bitrate = 0
 vbv_buffer_size = 0
 fps_num = 60
 fps_den = 1
+threads = 1
 
 [x264.lan]
 # inherits default

tests/xrdp/gfx/gfx_h264_encoder_x264.toml

@@ -19,6 +19,7 @@ vbv_max_bitrate = 0
 vbv_buffer_size = 0
 fps_num = 60
 fps_den = 1
+threads = 1
 
 [x264.lan]
 # inherits default

xrdp/gfx.toml

@@ -19,6 +19,7 @@ vbv_max_bitrate = 0
 vbv_buffer_size = 0
 fps_num = 60
 fps_den = 1
+threads = 1          # recommended: 1 or 2, see `man gfx.toml` for details
 
 [x264.lan]
 # inherits default

xrdp/xrdp_encoder_x264.c

@@ -153,7 +153,7 @@ xrdp_encoder_x264_encode(void *handle, int session, int left, int top,
             x264_param_default_preset(&(xe->x264_params),
                                       xg->x264_param[ct].preset,
                                       xg->x264_param[ct].tune);
-            xe->x264_params.i_threads = 1;
+            xe->x264_params.i_threads = xg->x264_param[ct].threads;
             xe->x264_params.i_width = (width + 15) & ~15;
             xe->x264_params.i_height = (height + 15) & ~15;
             xe->x264_params.i_fps_num = xg->x264_param[ct].fps_num;

xrdp/xrdp_tconfig.c

@@ -47,6 +47,7 @@
 #define X264_DEFAULT_PROFILE "main"
 #define X264_DEFAULT_FPS_NUM 24
 #define X264_DEFAULT_FPS_DEN 1
+#define X264_DEFAULT_THREADS 1 /* not to exhaust CPU threads for 1 user */
 
 const char *
 tconfig_codec_order_to_str(
@@ -334,6 +335,33 @@ tconfig_load_gfx_x264_ct(toml_table_t *tfile, const int connection_type,
         param[connection_type].fps_den = X264_DEFAULT_FPS_DEN;
     }
 
+    /* threads */
+    datum = toml_int_in(x264_ct, "threads");
+    if (datum.ok)
+    {
+        if (datum.u.i >= 0)
+        {
+            param[connection_type].threads = datum.u.i;
+        }
+        else
+        {
+            TCLOG(LOG_LEVEL_WARNING,
+                  "[x264.%s] an invalid value (< 0) is specified for threads, "
+                  "adopting the default value [%d]",
+                  rdpbcgr_connection_type_names[connection_type],
+                  X264_DEFAULT_THREADS);
+            param[connection_type].threads = X264_DEFAULT_THREADS;
+        }
+    }
+    else if (connection_type == 0)
+    {
+        TCLOG(LOG_LEVEL_WARNING,
+              "[x264.%s] threads is not set, adopting the default value [%d]",
+              rdpbcgr_connection_type_names[connection_type],
+              X264_DEFAULT_THREADS);
+        param[connection_type].threads = X264_DEFAULT_THREADS;
+    }
+
     return 0;
 }
 

xrdp/xrdp_tconfig.h

@@ -42,6 +42,7 @@ struct xrdp_tconfig_gfx_x264_param
     int vbv_buffer_size;
     int fps_num;
     int fps_den;
+    int threads;
 };
 
 struct xrdp_tconfig_gfx_openh264_param