diff options
| author | Sjoerd Simons <sjoerd.simons@collabora.co.uk> | 2009-03-01 19:55:26 +0100 |
|---|---|---|
| committer | Sebastian Dröge <sebastian.droege@collabora.co.uk> | 2009-03-01 19:55:26 +0100 |
| commit | b6755a70004a445a475e6c4b1c2d289e908cf2a9 (patch) | |
| tree | d6e4111b21d477cdfdbc4e3f84af1ead54ec2550 /sys/v4l2/v4l2src_calls.c | |
| parent | 7087da96dc850a931f7fca4c036fb0a2c58f04ac (diff) | |
Wait for a frame to become available before capturing it
Use GstPoll to wait for the fd of the video device to become readable before
trying to capture a frame. This speeds up stopping v4l2src a lot as it no
longer has to wait for the next frame, especially when capturing with low
framerates or when the video device just never generates a frame (which seems a
common issue for uvcvideo devices)
Fixes bug #563574.
Diffstat (limited to 'sys/v4l2/v4l2src_calls.c')
| -rw-r--r-- | sys/v4l2/v4l2src_calls.c | 31 |
1 files changed, 29 insertions, 2 deletions
diff --git a/sys/v4l2/v4l2src_calls.c b/sys/v4l2/v4l2src_calls.c index 971868bf..5abfda31 100644 --- a/sys/v4l2/v4l2src_calls.c +++ b/sys/v4l2/v4l2src_calls.c @@ -976,7 +976,7 @@ default_frame_sizes: /****************************************************** * gst_v4l2src_grab_frame (): * grab a frame for capturing - * return value: GST_FLOW_OK or GST_FLOW_ERROR + * return value: GST_FLOW_OK, GST_FLOW_WRONG_STATE or GST_FLOW_ERROR ******************************************************/ GstFlowReturn gst_v4l2src_grab_frame (GstV4l2Src * v4l2src, GstBuffer ** buf) @@ -987,12 +987,28 @@ gst_v4l2src_grab_frame (GstV4l2Src * v4l2src, GstBuffer ** buf) GstBuffer *pool_buffer; gboolean need_copy; gint index; + gint ret; memset (&buffer, 0x00, sizeof (buffer)); buffer.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; buffer.memory = V4L2_MEMORY_MMAP; - while (v4l2_ioctl (v4l2src->v4l2object->video_fd, VIDIOC_DQBUF, &buffer) < 0) { + for (;;) { + ret = gst_poll_wait (v4l2src->v4l2object->poll, GST_CLOCK_TIME_NONE); + if (G_UNLIKELY (ret < 0)) { + if (errno == EBUSY) + goto stopped; +#ifdef G_OS_WIN32 + if (WSAGetLastError () != WSAEINTR) + goto select_error; +#else + if (errno != EAGAIN && errno != EINTR) + goto select_error; +#endif + } + + if (v4l2_ioctl (v4l2src->v4l2object->video_fd, VIDIOC_DQBUF, &buffer) >= 0) + break; GST_WARNING_OBJECT (v4l2src, "problem grabbing frame %d (ix=%d), trials=%d, pool-ct=%d, buf.flags=%d", @@ -1135,6 +1151,17 @@ gst_v4l2src_grab_frame (GstV4l2Src * v4l2src, GstBuffer ** buf) return GST_FLOW_OK; /* ERRORS */ +select_error: + { + GST_ELEMENT_ERROR (v4l2src, RESOURCE, READ, (NULL), + ("select error %d: %s (%d)", ret, g_strerror (errno), errno)); + return GST_FLOW_ERROR; + } +stopped: + { + GST_DEBUG ("stop called"); + return GST_FLOW_WRONG_STATE; + } einval: { GST_ELEMENT_ERROR (v4l2src, RESOURCE, FAILED, |