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

[Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>]

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 <bnvandana@xxxxxxxxx>
> ---
> 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);