Re: [Linux-kernel-mentees] [PATCH v8] v4l2-ctl: Print UVC meta info

[Shuah Khan]

On 9/24/19 5:04 AM, Vandana BN wrote:

Print UVC Metadata information in verbose mode.

Cam you add more information on what this Metadata is and how it
is used.

Signed-off-by: Vandana BN <bnvand...@gmail.com>
---
Changes since v7:
        Not to call print_meta_buffer, if V4L2_BUF_FLAG_ERROR is set or
bytesused is 0.
Changes since v6:
        Not to print PTS/SCR if not present.
        Remove loop in print_meta_buffer()
Changes since v5:
        Use proper print format.
        split fprintf.
Changes since v4:
        Print PTS and SCR info.
---
  utils/v4l2-ctl/v4l2-ctl-meta.cpp      | 39 +++++++++++++++++++++++++++
  utils/v4l2-ctl/v4l2-ctl-streaming.cpp | 15 ++++++-----
  utils/v4l2-ctl/v4l2-ctl.h             |  1 +
  3 files changed, 49 insertions(+), 6 deletions(-)

diff --git a/utils/v4l2-ctl/v4l2-ctl-meta.cpp b/utils/v4l2-ctl/v4l2-ctl-meta.cpp
index 75fbd6f4..eae7438f 100644
--- a/utils/v4l2-ctl/v4l2-ctl-meta.cpp
+++ b/utils/v4l2-ctl/v4l2-ctl-meta.cpp
@@ -127,3 +127,42 @@ void meta_list(cv4l_fd &fd)
                print_video_formats(fd, V4L2_BUF_TYPE_META_OUTPUT);
        }
  }
+
+struct vivid_uvc_meta_buf {
+       __u64 ns;
+       __u16 sof;
+       __u8 length;
+       __u8 flags;
+       __u8 buf[10];
+};
+
+#define UVC_STREAM_SCR (1 << 3)
+#define UVC_STREAM_PTS (1 << 2)
+
+void print_meta_buffer(FILE *f, cv4l_buffer &buf, cv4l_fmt &fmt, cv4l_queue &q)
+{
+       struct vivid_uvc_meta_buf *vbuf;
+       int buf_off = 0;
+
+       switch (fmt.g_pixelformat()) {
+       case V4L2_META_FMT_UVC:
+               fprintf(f, "UVC: ");

Can you make this "UVC: Metadata:" or something along the lines to
say what this is. It will be easeir for people to search for a key
word.

+               vbuf = (vivid_uvc_meta_buf *)q.g_dataptr(buf.g_index(), 0);
+
+               fprintf(f, "%.6fs sof: %4d len: %u flags: 0x%02x",
+                       (double)vbuf->ns / 1000000000.0,
+                       vbuf->sof,
+                       vbuf->length,
+                       vbuf->flags);
+               if (vbuf->flags & UVC_STREAM_PTS) {
+                       fprintf(f, " PTS: %u", le32toh(*(__u32*)(vbuf->buf)));
+                       buf_off = 4;
+               }
+               if (vbuf->flags & UVC_STREAM_SCR)
+                       fprintf(f, " STC: %u SOF counter: %u",
+                               le32toh(*(__u32*)(vbuf->buf + buf_off)),
+                               le16toh(*(__u16*)(vbuf->buf + buf_off + 4)));
+               fprintf(f, "\n");
+               break;
+       }
+}
diff --git a/utils/v4l2-ctl/v4l2-ctl-streaming.cpp 
b/utils/v4l2-ctl/v4l2-ctl-streaming.cpp
index 11157434..47b7d3f8 100644
--- a/utils/v4l2-ctl/v4l2-ctl-streaming.cpp
+++ b/utils/v4l2-ctl/v4l2-ctl-streaming.cpp
@@ -540,9 +540,9 @@ static void print_buffer(FILE *f, struct v4l2_buffer &buf)
        fprintf(f, "\n");
  }

-static void print_concise_buffer(FILE *f, cv4l_buffer &buf,

-                                fps_timestamps &fps_ts, int comp_perc,
-                                bool skip_ts = false)
+static void print_concise_buffer(FILE *f, cv4l_buffer &buf, cv4l_fmt &fmt,
+                                cv4l_queue &q, fps_timestamps &fps_ts,
+                                int comp_perc, bool skip_ts = false)
  {
        static double last_ts;

@@ -592,6 +592,9 @@ static void print_concise_buffer(FILE *f, cv4l_buffer &buf,

        if (fl)
                fprintf(f, " (%s)", bufferflags2s(fl).c_str());
        fprintf(f, "\n");
+       if (v4l_type_is_meta(buf.g_type()) && buf.g_bytesused(0) &&
+           !(buf.g_flags() & V4L2_BUF_FLAG_ERROR))
+               print_meta_buffer(f, buf, fmt, q);
  }

static void stream_buf_caps(cv4l_fd &fd, unsigned buftype)

@@ -1390,7 +1393,7 @@ static int do_handle_cap(cv4l_fd &fd, cv4l_queue &q, FILE 
*fout, int *index,
                if (!(buf.g_flags() & V4L2_BUF_FLAG_ERROR))
                        break;
                if (verbose)
-                       print_concise_buffer(stderr, buf, fps_ts, -1);
+                       print_concise_buffer(stderr, buf, fmt, q, fps_ts, -1);
                if (fd.qbuf(buf))
                        return QUEUE_ERROR;
        }
@@ -1412,7 +1415,7 @@ static int do_handle_cap(cv4l_fd &fd, cv4l_queue &q, FILE 
*fout, int *index,
        else if (buf.g_flags() & V4L2_BUF_FLAG_BFRAME)
                ch = 'B';
        if (verbose) {
-               print_concise_buffer(stderr, buf, fps_ts,
+               print_concise_buffer(stderr, buf, fmt, q, fps_ts,
                                     host_fd_to >= 0 ? 100 - comp_perc / 
comp_perc_count : -1);
                comp_perc_count = comp_perc = 0;
        }
@@ -1502,7 +1505,7 @@ static int do_handle_out(cv4l_fd &fd, cv4l_queue &q, FILE 
*fin, cv4l_buffer *cap
                double ts_secs = buf.g_timestamp().tv_sec + 
buf.g_timestamp().tv_usec / 1000000.0;
                fps_ts.add_ts(ts_secs, buf.g_sequence(), buf.g_field());
                if (verbose)
-                       print_concise_buffer(stderr, buf, fps_ts, -1);
+                       print_concise_buffer(stderr, buf, fmt, q, fps_ts, -1);

for (unsigned j = 0; j < buf.g_num_planes(); j++)

                        buf.s_bytesused(buf.g_length(j), j);
diff --git a/utils/v4l2-ctl/v4l2-ctl.h b/utils/v4l2-ctl/v4l2-ctl.h
index 5797d784..36051566 100644
--- a/utils/v4l2-ctl/v4l2-ctl.h
+++ b/utils/v4l2-ctl/v4l2-ctl.h
@@ -406,6 +406,7 @@ void meta_cmd(int ch, char *optarg);
  void meta_set(cv4l_fd &fd);
  void meta_get(cv4l_fd &fd);
  void meta_list(cv4l_fd &fd);
+void print_meta_buffer(FILE *f, cv4l_buffer &buf, cv4l_fmt &fmt, cv4l_queue 
&q);

// v4l2-ctl-subdev.cpp

  void subdev_usage(void);