BCM2835-V4L2: Ensure H264 header bytes get a sensible timestamp

H264 header come off VC with 0 timestamps, which means they get a
strange timestamp when processed with VC/kernel start times,
particularly if used with the inline header option.
Remember the last frame timestamp and use that if set, or otherwise
use the kernel start time.

https://github.com/raspberrypi/linux/issues/1836

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

diff --git a/drivers/media/platform/bcm2835/bcm2835-camera.c b/drivers/media/platform/bcm2835/bcm2835-camera.c
index 4f03949aecf3afbf2e04df38289447195a8847a6..e69731320f4e59249933bc21843913deab4a1209 100644 (file)
--- a/drivers/media/platform/bcm2835/bcm2835-camera.c
+++ b/drivers/media/platform/bcm2835/bcm2835-camera.c
@@ -356,8 +356,13 @@ static void buffer_cb(struct vchiq_mmal_instance *instance,
                }
        } else {
                if (dev->capture.frame_count) {
-                       if (dev->capture.vc_start_timestamp != -1 &&
-                           pts != 0) {
+                       if (dev->capture.vc_start_timestamp == -1) {
+                               buf->vb.vb2_buf.timestamp = ktime_get_ns();
+                               v4l2_dbg(1, bcm2835_v4l2_debug, &dev->v4l2_dev,
+                                "Buffer time set as current time - %lld",
+                                buf->vb.vb2_buf.timestamp);
+
+                       } else if(pts != 0) {
                                struct timeval timestamp;
                                s64 runtime_us = pts -
                                    dev->capture.vc_start_timestamp;
@@ -390,10 +395,27 @@ static void buffer_cb(struct vchiq_mmal_instance *instance,
                                buf->vb.vb2_buf.timestamp = timestamp.tv_sec * 1000000000ULL +
                                        timestamp.tv_usec * 1000ULL;
                        } else {
-                               buf->vb.vb2_buf.timestamp = ktime_get_ns();
+                               if (dev->capture.last_timestamp) {
+                                       buf->vb.vb2_buf.timestamp = dev->capture.last_timestamp;
+                                       v4l2_dbg(1, bcm2835_v4l2_debug, &dev->v4l2_dev,
+                                        "Buffer time set as last timestamp - %lld",
+                                        buf->vb.vb2_buf.timestamp);
+                               }
+                               else {
+                                       buf->vb.vb2_buf.timestamp =
+                                       dev->capture.kernel_start_ts.tv_sec  * 1000000000ULL +
+                                       dev->capture.kernel_start_ts.tv_usec * 1000ULL;
+                                       v4l2_dbg(1, bcm2835_v4l2_debug, &dev->v4l2_dev,
+                                        "Buffer time set as start timestamp - %lld",
+                                        buf->vb.vb2_buf.timestamp);
+                               }
                        }
+                       dev->capture.last_timestamp = buf->vb.vb2_buf.timestamp;
 
                        vb2_set_plane_payload(&buf->vb.vb2_buf, 0, length);
+                       v4l2_dbg(1, bcm2835_v4l2_debug, &dev->v4l2_dev,
+                               "Buffer has ts %llu",
+                               dev->capture.last_timestamp);
                        vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_DONE);
 
                        if (mmal_flags & MMAL_BUFFER_HEADER_FLAG_EOS &&
@@ -559,6 +581,8 @@ static int start_streaming(struct vb2_queue *vq, unsigned int count)
                         "Start time %lld size %d\n",
                         dev->capture.vc_start_timestamp, parameter_size);
 
+       dev->capture.last_timestamp = 0;
+
        v4l2_get_timestamp(&dev->capture.kernel_start_ts);
 
        /* enable the camera port */

diff --git a/drivers/media/platform/bcm2835/bcm2835-camera.h b/drivers/media/platform/bcm2835/bcm2835-camera.h
index e6aeb7e7e381de65d6c6586205069a4c5cd33274..7f8a68916a67001bc9241bce2928519a2ce1ba78 100644 (file)
--- a/drivers/media/platform/bcm2835/bcm2835-camera.h
+++ b/drivers/media/platform/bcm2835/bcm2835-camera.h
@@ -93,6 +93,8 @@ struct bm2835_mmal_dev {
                s64         vc_start_timestamp;
                /* Kernel start timestamp for streaming */
                struct timeval kernel_start_ts;
+               /* Timestamp of last frame */
+               u64             last_timestamp;
 
                struct vchiq_mmal_port  *port; /* port being used for capture */
                /* camera port being used for capture */