dcc-send: Encode and send gl_draw stream data to the remote client (v4)

For remote (or non-gl) clients, if a valid gl_draw stream exists,
then we first extract the dmabuf fd associated with the scanout and
share it with the encoder along with other key parameters such as
stride, width and height. Once the encoder finishes creating an
encoded buffer (using the dmabuf fd as input), we then send it
over to the client. And, as soon as the encoder notifies that it
is no longer using the dmabuf fd, we send a gl_draw_done async to
the application.

v2: (suggestions and fixups from Frediano)
- Moved the DisplayStreamData initialization code from
  red_marshall_stream_data() into a separate function that is reused
  when marshalling gl_draw_stream.
- Used new/delete instead of g_new/g_free for creating and destroying
  dmabuf_data object
- s/notify_mem_free/free
  s/red_gst_mem_free_cb/red_free_fb
- Removed the usage of opaque from red_free_cb

v3:
- Obtain the key params such as fd, stride, etc from the stream instead
  of the scanout
- Replace the switch with if in red_marshall_gl_draw_stream() to avoid
  printing a warning (and spamming the console) when a frame is dropped

v4:
- Slightly improve the readability of red_marshall_gl_draw_stream() by
  adding checks at the start

Cc: Frediano Ziglio <freddy77@gmail.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Marc-André Lureau <marcandre.lureau@redhat.com>
Cc: Dongwon Kim <dongwon.kim@intel.com>
Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com>

server/dcc-send.cpp

@@ -1637,6 +1637,60 @@ static void red_release_video_encoder_buffer(uint8_t *data, void *opaque)
     buffer->free(buffer);
 }
 
+static void red_init_display_stream_data(DisplayChannelClient *dcc,
+                                         SpiceMarshaller *base_marshaller,
+                                         Drawable *drawable, int stream_id,
+                                         VideoBuffer *outbuf, int is_sized)
+{
+    SpiceMsgDisplayStreamData stream_data;
+    SpiceMsgDisplayStreamDataSized stream_data_sized;
+    SpiceStreamDataHeader *base;
+    SpiceCopy *copy;
+    uint32_t frame_mm_time = reds_get_mm_time();
+    uint16_t msg_type = is_sized ? SPICE_MSG_DISPLAY_STREAM_DATA_SIZED :
+                        SPICE_MSG_DISPLAY_STREAM_DATA;
+
+    dcc->init_send_data(msg_type);
+
+    base = is_sized ? &stream_data_sized.base : &stream_data.base;
+    base->id = stream_id;
+    base->multi_media_time = frame_mm_time;
+    stream_data.data_size = outbuf->size;
+
+    if (is_sized) {
+        copy = &drawable->red_drawable->u.copy;
+        frame_mm_time = drawable->red_drawable->mm_time ?
+                        drawable->red_drawable->mm_time :
+                        reds_get_mm_time();
+
+        stream_data_sized.base.multi_media_time = frame_mm_time;
+        stream_data_sized.width = copy->src_area.right - copy->src_area.left;
+        stream_data_sized.height = copy->src_area.bottom - copy->src_area.top;
+        stream_data_sized.dest = drawable->red_drawable->bbox;
+        stream_data_sized.data_size = outbuf->size;
+
+        spice_debug("stream %d: sized frame: dest ==> ",
+                    stream_data_sized.base.id);
+        rect_debug(&stream_data_sized.dest);
+        spice_marshall_msg_display_stream_data_sized(base_marshaller,
+                                                     &stream_data_sized);
+    } else {
+        spice_marshall_msg_display_stream_data(base_marshaller, &stream_data);
+    }
+
+    spice_marshaller_add_by_ref_full(base_marshaller, outbuf->data,
+                                     outbuf->size,
+                                     &red_release_video_encoder_buffer,
+                                     outbuf);
+#ifdef STREAM_STATS
+    VideoStreamAgent *agent = &dcc->priv->stream_agents[stream_id];
+
+    agent->stats.num_frames_sent++;
+    agent->stats.size_sent += outbuf->size;
+    agent->stats.end = frame_mm_time;
+#endif
+}
+
 static bool red_marshall_stream_data(DisplayChannelClient *dcc,
                                      SpiceMarshaller *base_marshaller,
                                      Drawable *drawable)
@@ -1693,43 +1747,83 @@ static bool red_marshall_stream_data(DisplayChannelClient *dcc,
         return FALSE;
     }
 
-    if (!is_sized) {
-        SpiceMsgDisplayStreamData stream_data;
-
-        dcc->init_send_data(SPICE_MSG_DISPLAY_STREAM_DATA);
-
-        stream_data.base.id = stream_id;
-        stream_data.base.multi_media_time = frame_mm_time;
-        stream_data.data_size = outbuf->size;
-
-        spice_marshall_msg_display_stream_data(base_marshaller, &stream_data);
-    } else {
-        SpiceMsgDisplayStreamDataSized stream_data;
-
-        dcc->init_send_data(SPICE_MSG_DISPLAY_STREAM_DATA_SIZED);
-
-        stream_data.base.id = stream_id;
-        stream_data.base.multi_media_time = frame_mm_time;
-        stream_data.data_size = outbuf->size;
-        stream_data.width = copy->src_area.right - copy->src_area.left;
-        stream_data.height = copy->src_area.bottom - copy->src_area.top;
-        stream_data.dest = drawable->red_drawable->bbox;
-
-        spice_debug("stream %d: sized frame: dest ==> ", stream_data.base.id);
-        rect_debug(&stream_data.dest);
-        spice_marshall_msg_display_stream_data_sized(base_marshaller, &stream_data);
-    }
-    spice_marshaller_add_by_ref_full(base_marshaller, outbuf->data, outbuf->size,
-                                     &red_release_video_encoder_buffer, outbuf);
-#ifdef STREAM_STATS
-    agent->stats.num_frames_sent++;
-    agent->stats.size_sent += outbuf->size;
-    agent->stats.end = frame_mm_time;
-#endif
-
+    red_init_display_stream_data(dcc, base_marshaller, drawable,
+                                 stream_id, outbuf, is_sized);
     return TRUE;
 }
 
+static void red_free_cb(VideoEncoderDmabufData *dmabuf_data)
+{
+    auto dcc = static_cast<DisplayChannelClient *>(dmabuf_data->dcc);
+    DisplayChannel *display = DCC_TO_DC(dcc);
+
+    dcc->priv->gl_draw_ongoing = false;
+    display_channel_gl_draw_done(display);
+    delete dmabuf_data;
+}
+
+static void red_marshall_gl_draw_stream(DisplayChannelClient *dcc,
+                                        SpiceMarshaller *base_marshaller)
+{
+    DisplayChannel *display = DCC_TO_DC(dcc);
+    VideoStream *stream = display->priv->gl_draw_stream;
+    int stream_id = display_channel_get_video_stream_id(display, stream);
+    VideoStreamAgent *agent = &dcc->priv->stream_agents[stream_id];
+
+    if (!agent->video_encoder || !agent->video_encoder->encode_dmabuf) {
+        spice_warning("No video encoder available for this stream");
+        return;
+    }
+
+    VideoEncoderDmabufData *dmabuf_data = new VideoEncoderDmabufData;
+    if (!dmabuf_data) {
+        spice_warning("Cannot create memory for dmabuf data");
+        return;
+    }
+
+    QXLInstance* qxl = display->priv->qxl;
+    SpiceMsgDisplayGlScanoutUnix *scanout = red_qxl_get_gl_scanout(qxl);
+    if (!scanout) {
+        spice_warning("Cannot access scanout");
+        delete dmabuf_data;
+        return;
+    }
+
+    dmabuf_data->drm_dma_buf_fd = scanout->drm_dma_buf_fd;
+    dmabuf_data->width = stream->width;
+    dmabuf_data->height = stream->height;
+    dmabuf_data->stride = stream->stride;
+    dmabuf_data->dcc = dcc;
+    dmabuf_data->free = red_free_cb;
+    red_qxl_put_gl_scanout(qxl, scanout);
+
+    VideoBuffer *outbuf;
+    VideoEncodeResults ret;
+
+    ret = agent->video_encoder->encode_dmabuf(agent->video_encoder,
+                                              reds_get_mm_time(),
+                                              dmabuf_data, &outbuf);
+
+    if (ret != VIDEO_ENCODER_FRAME_ENCODE_DONE) {
+        if (ret == VIDEO_ENCODER_FRAME_DROP) {
+#ifdef STREAM_STATS
+            agent->stats.num_drops_fps++;
+#endif
+        } else {
+            spice_warning("bad ret value (%d) from VideoEncoder::encode_dmabuf",
+                          ret);
+        }
+
+        dcc->priv->gl_draw_ongoing = false;
+        display_channel_gl_draw_done(display);
+        delete dmabuf_data;
+        return;
+    }
+
+    red_init_display_stream_data(dcc, base_marshaller, nullptr,
+                                 stream_id, outbuf, false);
+}
+
 static inline void marshall_inval_palette(RedChannelClient *rcc,
                                           SpiceMarshaller *base_marshaller,
                                           RedCachePipeItem *cache_item)
@@ -2126,6 +2220,8 @@ static void marshall_stream_start(DisplayChannelClient *dcc,
     if (stream->current) {
         RedDrawable *red_drawable = stream->current->red_drawable.get();
         stream_create.clip = red_drawable->clip;
+    } else if (stream == DCC_TO_DC(dcc)->priv->gl_draw_stream){
+        stream_create.clip.type = SPICE_CLIP_TYPE_NONE;
     } else {
         stream_create.clip.type = SPICE_CLIP_TYPE_RECTS;
         clip_rects.num_rects = 0;
@@ -2275,14 +2371,20 @@ static void marshall_gl_scanout(DisplayChannelClient *dcc,
     red_qxl_put_gl_scanout(qxl, scanout);
 }
 
-static void marshall_gl_draw(RedChannelClient *rcc,
+static void marshall_gl_draw(DisplayChannelClient *dcc,
                              SpiceMarshaller *m,
                              RedPipeItem *item)
 {
     auto p = static_cast<RedGlDrawItem*>(item);
 
-    rcc->init_send_data(SPICE_MSG_DISPLAY_GL_DRAW);
-    spice_marshall_msg_display_gl_draw(m, &p->draw);
+    if (dcc->is_gl_client()) {
+        dcc->init_send_data(SPICE_MSG_DISPLAY_GL_DRAW);
+        spice_marshall_msg_display_gl_draw(m, &p->draw);
+    } else if (DCC_TO_DC(dcc)->priv->gl_draw_stream) {
+        red_marshall_gl_draw_stream(dcc, m);
+    } else {
+        spice_warning("nothing to send to the client");
+    }
 }
 
 

server/video-encoder.h

@@ -56,6 +56,15 @@ typedef struct VideoEncoderStats {
     double avg_quality;
 } VideoEncoderStats;
 
+typedef struct VideoEncoderDmabufData {
+    int drm_dma_buf_fd;
+    uint32_t width;
+    uint32_t height;
+    uint32_t stride;
+    void *dcc;
+    void (*free)(struct VideoEncoderDmabufData*);
+} VideoEncoderDmabufData;
+
 typedef struct VideoEncoder VideoEncoder;
 struct VideoEncoder {
     /* Releases the video encoder's resources */
@@ -84,6 +93,10 @@ struct VideoEncoder {
                                        const SpiceRect *src, int top_down,
                                        gpointer bitmap_opaque, VideoBuffer** outbuf);
 
+    VideoEncodeResults (*encode_dmabuf)(VideoEncoder *encoder, uint32_t frame_mm_time,
+                                        VideoEncoderDmabufData *dmabuf_data,
+                                        VideoBuffer** outbuf);
+
     /*
      * Bit rate control methods.
      */