server/red_worker.c: use the bit rate of old streams as a start point for new streams

mjpeg_encoder modify the initial bit we supply it, according to the
client feedback. If it reaches a bit rate which is higher than the
initial one, we use the higher bit rate as the new bit rate estimation.

3 files changed, 22 insertions, 1 deletions

diff --git a/server/mjpeg_encoder.c b/server/mjpeg_encoder.c
index 7328ea26..b1010e0d 100644
--- a/server/mjpeg_encoder.c
+++ b/server/mjpeg_encoder.c
@@ -1247,3 +1247,8 @@ static void mjpeg_encoder_process_server_drops(MJpegEncoder *encoder)
     server_state->num_frames_encoded = 0;
     server_state->num_frames_dropped = 0;
 }
+
+uint64_t mjpeg_encoder_get_bit_rate(MJpegEncoder *encoder)
+{
+    return encoder->rate_control.byte_rate * 8;
+}
diff --git a/server/mjpeg_encoder.h b/server/mjpeg_encoder.h
index 0ee2e962..310d2892 100644
--- a/server/mjpeg_encoder.h
+++ b/server/mjpeg_encoder.h
@@ -102,4 +102,6 @@ void mjpeg_encoder_client_stream_report(MJpegEncoder *encoder,
  */
 void mjpeg_encoder_notify_server_frame_drop(MJpegEncoder *encoder);
 
+uint64_t mjpeg_encoder_get_bit_rate(MJpegEncoder *encoder);
+
 #endif
diff --git a/server/red_worker.c b/server/red_worker.c
index f96ff076..8e30ef38 100644
--- a/server/red_worker.c
+++ b/server/red_worker.c
@@ -693,6 +693,7 @@ struct DisplayChannelClient {
     StreamAgent stream_agents[NUM_STREAMS];
     int use_mjpeg_encoder_rate_control;
     uint32_t streams_max_latency;
+    uint64_t streams_max_bit_rate;
 };
 
 struct DisplayChannel {
@@ -2616,6 +2617,16 @@ static void red_stop_stream(RedWorker *worker, Stream *stream)
         region_clear(&stream_agent->vis_region);
         region_clear(&stream_agent->clip);
         spice_assert(!pipe_item_is_linked(&stream_agent->destroy_item));
+        if (stream_agent->mjpeg_encoder && dcc->use_mjpeg_encoder_rate_control) {
+            uint64_t stream_bit_rate = mjpeg_encoder_get_bit_rate(stream_agent->mjpeg_encoder);
+
+            if (stream_bit_rate > dcc->streams_max_bit_rate) {
+                spice_debug("old max-bit-rate=%.2f new=%.2f",
+                dcc->streams_max_bit_rate / 8.0 / 1024.0 / 1024.0,
+                stream_bit_rate / 8.0 / 1024.0 / 1024.0);
+                dcc->streams_max_bit_rate = stream_bit_rate;
+            }
+        }
         stream->refs++;
         red_channel_client_pipe_add(&dcc->common.base, &stream_agent->destroy_item);
     }
@@ -2874,10 +2885,13 @@ static uint64_t red_stream_get_initial_bit_rate(DisplayChannelClient *dcc,
     mcc = red_client_get_main(dcc->common.base.client);
     max_bit_rate = main_channel_client_get_bitrate_per_sec(mcc);
 
+    if (max_bit_rate > dcc->streams_max_bit_rate) {
+        dcc->streams_max_bit_rate = max_bit_rate;
+    }
 
     /* dividing the available bandwidth among the active streams, and saving
      * (1-RED_STREAM_CHANNEL_CAPACITY) of it for other messages */
-    return (RED_STREAM_CHANNEL_CAPACITY * max_bit_rate *
+    return (RED_STREAM_CHANNEL_CAPACITY * dcc->streams_max_bit_rate *
            stream->width * stream->height) / dcc->common.worker->streams_size_total;
 }