commit 309dd72c9be9a2ef8bbbba29adb64d53a2536b8b
author Parker Schuh <parker.schuh+gerrit_code_review@gmail.com> Sat Feb 25 11:31:18 2017 -0800
committer Parker Schuh <parker.schuh+gerrit_code_review@gmail.com> Sun Feb 26 13:23:46 2017 -0800
tree 85ae669b983844f1d6013cbf294a9adacc3718dc
parent 009b09ffa5200866c10c3147be915d0827589953

Sundry tweaks to aos/vision libs

Change-Id: Ia5578dcf2d42ac53b81af239bf329eb084fcf1d9

aos/vision/image/reader.h

diff --git a/aos/vision/image/reader.h b/aos/vision/image/reader.h
index eabb80a..28735fb 100644
--- a/aos/vision/image/reader.h
+++ b/aos/vision/image/reader.h
@@ -41,8 +41,8 @@
 
   void HandleFrame();
   void StartAsync() {
-    Start();
     MMapBuffers();
+    Start();
   }
   int fd() { return fd_; }
 
@@ -60,6 +60,7 @@
 
   ProcessCb process_;
 
+  int tick_id_ = 0;
   // The number of buffers currently queued in v4l2.
   uint32_t queued_;
   struct Buffer;
@@ -67,7 +68,10 @@
   // because the buffers are not ummapped.
   Buffer *buffers_;
 
-  static const unsigned int kNumBuffers = 10;
+  // TODO(parker): The timestamps should be queue insertion timestamps
+  // which will remove the impact of kNumBuffers.
+  // TODO(parker): Flush the queue (or tweak the FPS) if we fall behind.
+  static const unsigned int kNumBuffers = 5;
 
   // set only at initialize
   CameraParams params_;