Capture pipeline timestamps

cmd/camera.c

@@ -56,6 +56,7 @@ camera_t *camera_open(camera_options_t *options)
   if (device_open_buffer_list(camera->camera, true, camera->options.width, camera->options.height, camera->options.format, 0, camera->options.nbufs, true) < 0) {
     goto error;
   }
+  camera->camera->capture_list->do_timestamps = true;
 
   switch (camera->camera->capture_list->fmt_format) {
   case V4L2_PIX_FMT_YUYV:

hw/buffer.h

@@ -17,7 +17,6 @@ typedef struct buffer_s {
   int mmap_reflinks;
   struct buffer_s *mmap_source;
   bool enqueued;
-  uint64_t enqueued_time_us;
 } buffer_t;
 
 buffer_t *buffer_open(const char *name, struct buffer_list_s *buf_list, int buffer);

hw/buffer_list.h

@@ -16,6 +16,7 @@ typedef struct buffer_list_s {
   bool do_capture;
 
   unsigned fmt_width, fmt_height, fmt_format, fmt_bytesperline;
+  bool do_timestamps;
 
   bool streaming;
   int frames;

hw/buffer_lock.c

@@ -44,7 +44,10 @@ void buffer_lock_capture(buffer_lock_t *buf_lock, buffer_t *buf)
   buf_lock->buf = buf;
   buf_lock->counter++;
   buf_lock->buf_time_us = get_monotonic_time_us(NULL, NULL);
-  E_LOG_DEBUG(buf_lock, "Captured buffer %s (refs=%d), frame=%d", dev_name(buf), buf ? buf->mmap_reflinks : 0, buf_lock->counter);
+  uint64_t captured_time_s = get_time_us(CLOCK_FROM_PARAMS, NULL, &buf->v4l2_buffer.timestamp, 0);
+  E_LOG_DEBUG(buf_lock, "Captured buffer %s (refs=%d), frame=%d, delay=%llus",
+    dev_name(buf), buf ? buf->mmap_reflinks : 0, buf_lock->counter,
+    buf_lock->buf_time_us - captured_time_s);
   pthread_cond_broadcast(&buf_lock->cond_wait);
   pthread_mutex_unlock(&buf_lock->lock);
 }

hw/buffer_queue.c

@@ -51,7 +51,11 @@ bool buffer_consumed(buffer_t *buf, const char *who)
       buf->length,
       buf->mmap_source ? buf->mmap_source->name : NULL,
       who);
-    buf->enqueued_time_us = get_monotonic_time_us(NULL, &buf->v4l2_buffer.timestamp);
+
+    if (buf->buf_list->do_timestamps && !buf->buf_list->do_capture) {
+      get_monotonic_time_us(NULL, &buf->v4l2_buffer.timestamp);
+    }
+
     E_XIOCTL(buf, buf->buf_list->device->fd, VIDIOC_QBUF, &buf->v4l2_buffer, "Can't queue buffer.");
     buf->enqueued = true;
   }
@@ -116,6 +120,7 @@ int buffer_list_enqueue(buffer_list_t *buf_list, buffer_t *dma_buf)
   buf->v4l2_buffer.flags = 0;
   buf->v4l2_buffer.flags &= ~V4L2_BUF_FLAG_KEYFRAME;
   buf->v4l2_buffer.flags |= dma_buf->v4l2_buffer.flags & V4L2_BUF_FLAG_KEYFRAME;
+  buf->v4l2_buffer.timestamp = dma_buf->v4l2_buffer.timestamp;
 
   if (buf_list->do_mmap) {
     if (dma_buf->used > buf->length) {
@@ -175,21 +180,25 @@ buffer_t *buffer_list_dequeue(buffer_list_t *buf_list)
   }
   buf->v4l2_buffer.flags = v4l2_buf.flags;
 
+  if (buf_list->do_timestamps && buf_list->do_capture) {
+    get_monotonic_time_us(NULL, &buf->v4l2_buffer.timestamp);
+  } else {
+    buf->v4l2_buffer.timestamp = v4l2_buf.timestamp;
+  }
+
   if (buf->mmap_reflinks > 0) {
     E_LOG_PERROR(buf, "Buffer appears to be enqueued? (links=%d)", buf->mmap_reflinks);
   }
 
   buf->enqueued = false;
   buf->mmap_reflinks = 1;
-  uint64_t enqueued_time_us = get_monotonic_time_us(NULL, NULL) - buf->enqueued_time_us;
 
-	E_LOG_DEBUG(buf_list, "Grabbed mmap buffer=%u, bytes=%d, used=%d, frame=%d, linked=%s, enqueued_time_us=%lluus, flags=%08x",
+	E_LOG_DEBUG(buf_list, "Grabbed mmap buffer=%u, bytes=%d, used=%d, frame=%d, linked=%s, flags=%08x",
     buf->index,
     buf->length,
     buf->used,
     buf_list->frames,
     buf->mmap_source ? buf->mmap_source->name : NULL,
-    enqueued_time_us,
     buf->v4l2_buffer.flags);
 
   if (buf->mmap_source) {

hw/v4l2.c

@@ -83,7 +83,17 @@ int shrink_to_block(int size, int block)
 uint64_t get_time_us(clockid_t clock, struct timespec *ts, struct timeval *tv, int64_t delays_us)
 {
 	struct timespec now;
-	clock_gettime(clock, &now);
+
+	if (clock != CLOCK_FROM_PARAMS) {
+		clock_gettime(clock, &now);
+	} else if (ts) {
+		now = *ts;
+	} else if (tv) {
+		now.tv_sec = tv->tv_sec;
+		now.tv_nsec = tv->tv_usec * 1000;
+	} else {
+		return -1;
+	}
 
 	if (delays_us > 0) {
 		#define NS_IN_S (1000LL * 1000LL * 1000LL)

hw/v4l2.h

@@ -30,6 +30,8 @@ typedef struct {
 	char buf[10];
 } fourcc_string;
 
+#define CLOCK_FROM_PARAMS -1
+
 fourcc_string fourcc_to_string(unsigned format);
 unsigned fourcc_to_stride(unsigned width, unsigned format);
 int xioctl(const char *name, int fd, int request, void *arg);