Ticket #1679: fps-converter.patch

pjmedia/include/pjmedia/port.h

@@ -232 +232 @@
     pj_uint32_t     signature;          /**< Port signature.                */
     pjmedia_dir     dir;                /**< Port direction.                */
     pjmedia_format  fmt;                /**< Format.                        */
+    pj_uint32_t     frames_counter;             /**< Frames counter, important for manipulating FPS.                */
+    pj_uint32_t     src_frames_block_size;      /**< Size of the frames block if we need to manupulate FPS   */
+    pj_uint32_t     dst_skip_frames;    /**< Skip all frames with number higher than this value             */
 } pjmedia_port_info;
 
 /**

pjmedia/src/pjmedia/port.c

@@ -69 +69 @@
     info->signature = signature;
     info->dir = dir;
     info->name = *name;
+        info->frames_counter = 0;
+    info->src_frames_block_size = 0;
+    info->dst_skip_frames = 0;
 
     pjmedia_format_copy(&info->fmt, fmt);
 

pjmedia/src/pjmedia/vid_tee.c

@@ -293 +293 @@
     return PJ_ENOTFOUND;
 }
 
+int greatest_common_divisor(int a, int b)
+{
+        if(b == 0)
+        {
+                return a;
+        }
+        else
+        {
+                return greatest_common_divisor(b, a % b);
+        }
+}
+
+void calculate_vid_tee_port_fps_variables(pjmedia_port_info *src, pjmedia_port_info *dst)
+{
+        int src_fps, dst_fps, divisor;
+
+        src_fps = src->fmt.det.vid.fps.num / src->fmt.det.vid.fps.denum;
+        dst_fps = dst->fmt.det.vid.fps.num / dst->fmt.det.vid.fps.denum;
+
+        if(dst_fps < src_fps)
+        {
+                divisor = greatest_common_divisor(src_fps, dst_fps);
+
+                dst->src_frames_block_size = src_fps / divisor;
+                dst->dst_skip_frames = dst_fps / divisor;
+        }
+        else
+        {
+                /* just to disable future calculations from above */
+                dst->frames_counter = -1;
+        }
+}
 
 static pj_status_t tee_put_frame(pjmedia_port *port, pjmedia_frame *frame)
 {
     vid_tee_port *tee = (vid_tee_port*)port;
     unsigned i, j;
     const pj_uint8_t PUT_FRM_DONE = 1;
+        pj_bool_t deliver_data = PJ_TRUE;
 
     pj_bzero(tee->put_frm_flag, tee->dst_port_cnt *
                                 sizeof(tee->put_frm_flag[0]));
@@ -354 +387 @@
                 framep.size = frame_.size;
                 pj_memcpy(framep.buf, frame_.buf, frame_.size);
             }
+        
+                        /* first frame to be sent */
+                        if(tee->dst_ports[j].dst->info.frames_counter == 0)
+                        {
+                                calculate_vid_tee_port_fps_variables(&tee->base.info, &tee->dst_ports[j].dst->info);
+                        }
+
+                        if(tee->dst_ports[j].dst->info.src_frames_block_size > 0)
+                        {
+                                /* send frames higher than dst_skip_frames of every src_frames_block_size frames */
+                                int num = tee->dst_ports[j].dst->info.frames_counter % tee->dst_ports[j].dst->info.src_frames_block_size;
+                                if( num >= tee->dst_ports[j].dst->info.dst_skip_frames)
+                                {
+                                        deliver_data = PJ_FALSE;
+                                }
+                                ++tee->dst_ports[j].dst->info.frames_counter;
+                        }
+
+                        if(deliver_data)
+                        {
+                                /* Deliver the data */
+                                pjmedia_port_put_frame(tee->dst_ports[j].dst, &framep);
+                        }
+                        tee->put_frm_flag[j] = PUT_FRM_DONE;
 
-            /* Deliver the data */
-            pjmedia_port_put_frame(tee->dst_ports[j].dst, &framep);
-            tee->put_frm_flag[j] = PUT_FRM_DONE;
-            
             if (!tee->tee_conv[i].conv)
                 break;
         }