From 9aa07bd7bae08345e213c201021c9e29b67627b2 Mon Sep 17 00:00:00 2001 From: Laurent Pinchart Date: Tue, 25 Oct 2011 10:14:22 +0200 Subject: Use monotonic clock to retrieve timestamps Signed-off-by: Laurent Pinchart --- yavta.c | 28 +++++++++++++++------------- 1 file changed, 15 insertions(+), 13 deletions(-) (limited to 'yavta.c') diff --git a/yavta.c b/yavta.c index ffb7c1b..893fa4e 100644 --- a/yavta.c +++ b/yavta.c @@ -26,6 +26,7 @@ #include #include #include +#include #include #include #include @@ -949,9 +950,9 @@ static int video_do_capture(struct device *dev, unsigned int nframes, int do_requeue_last, enum buffer_fill_mode fill) { char *filename = NULL; - struct timeval start; + struct timespec start; struct timeval last; - struct timeval ts; + struct timespec ts; struct v4l2_buffer buf; unsigned int size; unsigned int i; @@ -970,8 +971,9 @@ static int video_do_capture(struct device *dev, unsigned int nframes, video_enable(dev, 1); size = 0; - gettimeofday(&start, NULL); - last = start; + clock_gettime(CLOCK_MONOTONIC, &start); + last.tv_sec = start.tv_sec; + last.tv_usec = start.tv_nsec / 1000; for (i = 0; i < nframes; ++i) { /* Dequeue a buffer. */ @@ -1004,11 +1006,11 @@ static int video_do_capture(struct device *dev, unsigned int nframes, + buf.timestamp.tv_usec - last.tv_usec; fps = fps ? 1000000.0 / fps : 0.0; - gettimeofday(&ts, NULL); + clock_gettime(CLOCK_MONOTONIC, &ts); printf("%u (%u) [%c] %u %u bytes %ld.%06ld %ld.%06ld %.3f fps\n", i, buf.index, (buf.flags & V4L2_BUF_FLAG_ERROR) ? 'E' : '-', buf.sequence, buf.bytesused, buf.timestamp.tv_sec, - buf.timestamp.tv_usec, ts.tv_sec, ts.tv_usec, fps); + buf.timestamp.tv_usec, ts.tv_sec, ts.tv_nsec/1000, fps); last = buf.timestamp; @@ -1048,21 +1050,21 @@ static int video_do_capture(struct device *dev, unsigned int nframes, goto done; } - if (ts.tv_sec == start.tv_sec && ts.tv_usec == start.tv_usec) + if (ts.tv_sec == start.tv_sec && ts.tv_nsec == start.tv_nsec) goto done; ts.tv_sec -= start.tv_sec; - ts.tv_usec -= start.tv_usec; - if (ts.tv_usec < 0) { + ts.tv_nsec -= start.tv_nsec; + if (ts.tv_nsec < 0) { ts.tv_sec--; - ts.tv_usec += 1000000; + ts.tv_nsec += 1000000000; } - bps = size/(ts.tv_usec+1000000.0*ts.tv_sec)*1000000.0; - fps = i/(ts.tv_usec+1000000.0*ts.tv_sec)*1000000.0; + bps = size/(ts.tv_nsec/1000.0+1000000.0*ts.tv_sec)*1000000.0; + fps = i/(ts.tv_nsec/1000.0+1000000.0*ts.tv_sec)*1000000.0; printf("Captured %u frames in %lu.%06lu seconds (%f fps, %f B/s).\n", - i, ts.tv_sec, ts.tv_usec, fps, bps); + i, ts.tv_sec, ts.tv_nsec/1000, fps, bps); done: free(filename); -- cgit v1.2.3