[Linux-kernel-mentees] [PATCH v3] v4l2-ctl: Print UVC meta info

Hans Verkuil hverkuil at xs4all.nl
Tue Sep 17 09:29:54 UTC 2019


On 9/16/19 8:00 PM, Vandana BN wrote:
> Print UVC Metadata information in verbose mode.
> 
> Signed-off-by: Vandana BN <bnvandana at gmail.com>
> ---
> Changes since v2
> - Converted if to switch statement.
> - Corrected format specifier in print.
> ---
>  utils/v4l2-ctl/v4l2-ctl-meta.cpp      | 25 +++++++++++++++++++++++++
>  utils/v4l2-ctl/v4l2-ctl-streaming.cpp | 14 ++++++++------
>  utils/v4l2-ctl/v4l2-ctl.h             |  1 +
>  3 files changed, 34 insertions(+), 6 deletions(-)
> 
> diff --git a/utils/v4l2-ctl/v4l2-ctl-meta.cpp b/utils/v4l2-ctl/v4l2-ctl-meta.cpp
> index 75fbd6f4..5d7b28d6 100644
> --- a/utils/v4l2-ctl/v4l2-ctl-meta.cpp
> +++ b/utils/v4l2-ctl/v4l2-ctl-meta.cpp
> @@ -127,3 +127,28 @@ 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[];
> +};
> +
> +void print_meta_buffer(FILE *f, cv4l_buffer &buf, cv4l_fmt &fmt, cv4l_queue &q)
> +{
> +	struct vivid_uvc_meta_buf *vbuf;
> +
> +	switch(fmt.g_pixelformat()) {

Add space before (

> +		case V4L2_META_FMT_UVC:

We use the kernel coding style, so the case statement should be aligned with the switch.

> +			fprintf(f, "UVC: ");
> +			for (unsigned i = 0; i < buf.g_num_planes(); i++) {
> +				vbuf = (vivid_uvc_meta_buf *)q.g_dataptr(buf.g_index(), i);
> +				fprintf(f, "%.6fs, sof %u, len %u, flags 0x%x\n",
> +						(double)vbuf[i].ns / 1000000000.0, vbuf[i].sof,
> +						vbuf[i].length, vbuf[i].flags);

Properly align the arguments:

				fprintf(f, "%.6fs, sof %u, len %u, flags 0x%x\n",
					(double)vbuf[i].ns / 1000000000.0, vbuf[i].sof,
					vbuf[i].length, vbuf[i].flags);

(looks like there was a tab too many for some reason)

These issues may seem like nitpicking, but from a code maintenance
perspective it is very important. It's like reading a book with a weird
layout, it's just harder to read.

Regards,

	Hans

> +			}
> +			break;
> +	}
> +}
> diff --git a/utils/v4l2-ctl/v4l2-ctl-streaming.cpp b/utils/v4l2-ctl/v4l2-ctl-streaming.cpp
> index 11157434..46d53f23 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 +592,8 @@ 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()))
> +		print_meta_buffer(f, buf, fmt, q);
>  }
>  
>  static void stream_buf_caps(cv4l_fd &fd, unsigned buftype)
> @@ -1390,7 +1392,7 @@ 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 +1414,7 @@ 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 +1504,7 @@ 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);
> 



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