From 25738cbd72db53ca1c326bf94915d41086cb4297 Mon Sep 17 00:00:00 2001 From: Laurent Pinchart Date: Thu, 3 Nov 2011 12:30:17 -0300 Subject: [PATCH] [media] uvcvideo: Extract timestamp-related statistics Signed-off-by: Laurent Pinchart Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/uvc/uvc_video.c | 125 +++++++++++++++++++++++++++- drivers/media/video/uvc/uvcvideo.h | 23 +++++ 2 files changed, 146 insertions(+), 2 deletions(-) diff --git a/drivers/media/video/uvc/uvc_video.c b/drivers/media/video/uvc/uvc_video.c index 1908dd859433..513ba30f8d57 100644 --- a/drivers/media/video/uvc/uvc_video.c +++ b/drivers/media/video/uvc/uvc_video.c @@ -365,6 +365,11 @@ static void uvc_video_stats_decode(struct uvc_streaming *stream, const __u8 *data, int len) { unsigned int header_size; + bool has_pts = false; + bool has_scr = false; + u16 uninitialized_var(scr_sof); + u32 uninitialized_var(scr_stc); + u32 uninitialized_var(pts); if (stream->stats.stream.nb_frames == 0 && stream->stats.frame.nb_packets == 0) @@ -373,12 +378,16 @@ static void uvc_video_stats_decode(struct uvc_streaming *stream, switch (data[1] & (UVC_STREAM_PTS | UVC_STREAM_SCR)) { case UVC_STREAM_PTS | UVC_STREAM_SCR: header_size = 12; + has_pts = true; + has_scr = true; break; case UVC_STREAM_PTS: header_size = 6; + has_pts = true; break; case UVC_STREAM_SCR: header_size = 8; + has_scr = true; break; default: header_size = 2; @@ -391,6 +400,63 @@ static void uvc_video_stats_decode(struct uvc_streaming *stream, return; } + /* Extract the timestamps. */ + if (has_pts) + pts = get_unaligned_le32(&data[2]); + + if (has_scr) { + scr_stc = get_unaligned_le32(&data[header_size - 6]); + scr_sof = get_unaligned_le16(&data[header_size - 2]); + } + + /* Is PTS constant through the whole frame ? */ + if (has_pts && stream->stats.frame.nb_pts) { + if (stream->stats.frame.pts != pts) { + stream->stats.frame.nb_pts_diffs++; + stream->stats.frame.last_pts_diff = + stream->stats.frame.nb_packets; + } + } + + if (has_pts) { + stream->stats.frame.nb_pts++; + stream->stats.frame.pts = pts; + } + + /* Do all frames have a PTS in their first non-empty packet, or before + * their first empty packet ? + */ + if (stream->stats.frame.size == 0) { + if (len > header_size) + stream->stats.frame.has_initial_pts = has_pts; + if (len == header_size && has_pts) + stream->stats.frame.has_early_pts = true; + } + + /* Do the SCR.STC and SCR.SOF fields vary through the frame ? */ + if (has_scr && stream->stats.frame.nb_scr) { + if (stream->stats.frame.scr_stc != scr_stc) + stream->stats.frame.nb_scr_diffs++; + } + + if (has_scr) { + /* Expand the SOF counter to 32 bits and store its value. */ + if (stream->stats.stream.nb_frames > 0 || + stream->stats.frame.nb_scr > 0) + stream->stats.stream.scr_sof_count += + (scr_sof - stream->stats.stream.scr_sof) % 2048; + stream->stats.stream.scr_sof = scr_sof; + + stream->stats.frame.nb_scr++; + stream->stats.frame.scr_stc = scr_stc; + stream->stats.frame.scr_sof = scr_sof; + + if (scr_sof < stream->stats.stream.min_sof) + stream->stats.stream.min_sof = scr_sof; + if (scr_sof > stream->stats.stream.max_sof) + stream->stats.stream.max_sof = scr_sof; + } + /* Record the first non-empty packet number. */ if (stream->stats.frame.size == 0 && len > header_size) stream->stats.frame.first_data = stream->stats.frame.nb_packets; @@ -411,9 +477,16 @@ static void uvc_video_stats_update(struct uvc_streaming *stream) { struct uvc_stats_frame *frame = &stream->stats.frame; - uvc_trace(UVC_TRACE_STATS, "frame %u stats: %u/%u/%u packets\n", + uvc_trace(UVC_TRACE_STATS, "frame %u stats: %u/%u/%u packets, " + "%u/%u/%u pts (%searly %sinitial), %u/%u scr, " + "last pts/stc/sof %u/%u/%u\n", stream->sequence, frame->first_data, - frame->nb_packets - frame->nb_empty, frame->nb_packets); + frame->nb_packets - frame->nb_empty, frame->nb_packets, + frame->nb_pts_diffs, frame->last_pts_diff, frame->nb_pts, + frame->has_early_pts ? "" : "!", + frame->has_initial_pts ? "" : "!", + frame->nb_scr_diffs, frame->nb_scr, + frame->pts, frame->scr_stc, frame->scr_sof); stream->stats.stream.nb_frames++; stream->stats.stream.nb_packets += stream->stats.frame.nb_packets; @@ -421,14 +494,47 @@ static void uvc_video_stats_update(struct uvc_streaming *stream) stream->stats.stream.nb_errors += stream->stats.frame.nb_errors; stream->stats.stream.nb_invalid += stream->stats.frame.nb_invalid; + if (frame->has_early_pts) + stream->stats.stream.nb_pts_early++; + if (frame->has_initial_pts) + stream->stats.stream.nb_pts_initial++; + if (frame->last_pts_diff <= frame->first_data) + stream->stats.stream.nb_pts_constant++; + if (frame->nb_scr >= frame->nb_packets - frame->nb_empty) + stream->stats.stream.nb_scr_count_ok++; + if (frame->nb_scr_diffs + 1 == frame->nb_scr) + stream->stats.stream.nb_scr_diffs_ok++; + memset(&stream->stats.frame, 0, sizeof(stream->stats.frame)); } size_t uvc_video_stats_dump(struct uvc_streaming *stream, char *buf, size_t size) { + unsigned int scr_sof_freq; + unsigned int duration; + struct timespec ts; size_t count = 0; + ts.tv_sec = stream->stats.stream.stop_ts.tv_sec + - stream->stats.stream.start_ts.tv_sec; + ts.tv_nsec = stream->stats.stream.stop_ts.tv_nsec + - stream->stats.stream.start_ts.tv_nsec; + if (ts.tv_nsec < 0) { + ts.tv_sec--; + ts.tv_nsec += 1000000000; + } + + /* Compute the SCR.SOF frequency estimate. At the nominal 1kHz SOF + * frequency this will not overflow before more than 1h. + */ + duration = ts.tv_sec * 1000 + ts.tv_nsec / 1000000; + if (duration != 0) + scr_sof_freq = stream->stats.stream.scr_sof_count * 1000 + / duration; + else + scr_sof_freq = 0; + count += scnprintf(buf + count, size - count, "frames: %u\npackets: %u\nempty: %u\n" "errors: %u\ninvalid: %u\n", @@ -437,6 +543,20 @@ size_t uvc_video_stats_dump(struct uvc_streaming *stream, char *buf, stream->stats.stream.nb_empty, stream->stats.stream.nb_errors, stream->stats.stream.nb_invalid); + count += scnprintf(buf + count, size - count, + "pts: %u early, %u initial, %u ok\n", + stream->stats.stream.nb_pts_early, + stream->stats.stream.nb_pts_initial, + stream->stats.stream.nb_pts_constant); + count += scnprintf(buf + count, size - count, + "scr: %u count ok, %u diff ok\n", + stream->stats.stream.nb_scr_count_ok, + stream->stats.stream.nb_scr_diffs_ok); + count += scnprintf(buf + count, size - count, + "sof: %u <= sof <= %u, freq %u.%03u kHz\n", + stream->stats.stream.min_sof, + stream->stats.stream.max_sof, + scr_sof_freq / 1000, scr_sof_freq % 1000); return count; } @@ -444,6 +564,7 @@ size_t uvc_video_stats_dump(struct uvc_streaming *stream, char *buf, static void uvc_video_stats_start(struct uvc_streaming *stream) { memset(&stream->stats, 0, sizeof(stream->stats)); + stream->stats.stream.min_sof = 2048; } static void uvc_video_stats_stop(struct uvc_streaming *stream) diff --git a/drivers/media/video/uvc/uvcvideo.h b/drivers/media/video/uvc/uvcvideo.h index f9ee62ed0150..e4d4b6d02024 100644 --- a/drivers/media/video/uvc/uvcvideo.h +++ b/drivers/media/video/uvc/uvcvideo.h @@ -364,6 +364,18 @@ struct uvc_stats_frame { unsigned int nb_empty; /* Number of empty packets */ unsigned int nb_invalid; /* Number of packets with an invalid header */ unsigned int nb_errors; /* Number of packets with the error bit set */ + + unsigned int nb_pts; /* Number of packets with a PTS timestamp */ + unsigned int nb_pts_diffs; /* Number of PTS differences inside a frame */ + unsigned int last_pts_diff; /* Index of the last PTS difference */ + bool has_initial_pts; /* Whether the first non-empty packet has a PTS */ + bool has_early_pts; /* Whether a PTS is present before the first non-empty packet */ + u32 pts; /* PTS of the last packet */ + + unsigned int nb_scr; /* Number of packets with a SCR timestamp */ + unsigned int nb_scr_diffs; /* Number of SCR.STC differences inside a frame */ + u16 scr_sof; /* SCR.SOF of the last packet */ + u32 scr_stc; /* SCR.STC of the last packet */ }; struct uvc_stats_stream { @@ -376,6 +388,17 @@ struct uvc_stats_stream { unsigned int nb_empty; /* Number of empty packets */ unsigned int nb_invalid; /* Number of packets with an invalid header */ unsigned int nb_errors; /* Number of packets with the error bit set */ + + unsigned int nb_pts_constant; /* Number of frames with constant PTS */ + unsigned int nb_pts_early; /* Number of frames with early PTS */ + unsigned int nb_pts_initial; /* Number of frames with initial PTS */ + + unsigned int nb_scr_count_ok; /* Number of frames with at least one SCR per non empty packet */ + unsigned int nb_scr_diffs_ok; /* Number of frames with varying SCR.STC */ + unsigned int scr_sof_count; /* STC.SOF counter accumulated since stream start */ + unsigned int scr_sof; /* STC.SOF of the last packet */ + unsigned int min_sof; /* Minimum STC.SOF value */ + unsigned int max_sof; /* Maximum STC.SOF value */ }; struct uvc_streaming { -- 2.30.2