Marcus Glocker said:
> Sometimes I just would like to query a video device for it's properties
> without starting a stream to see what's supported and evt. make a
> decision afterwards how to start the stream.
>
> This diff adds the 'q' option to video(1) for this purpose to just
> query the device, display the results, and quit.
>
> Anyone else find this useful?
I had this in my plans.
Tested on amd64 with Ricoh laptop camera (5986:03b4). OK czarkoff@.
> Index: video.1
> ===================================================================
> RCS file: /cvs/xenocara/app/video/video.1,v
> retrieving revision 1.12
> diff -u -p -u -p -r1.12 video.1
> --- video.1 31 May 2016 06:47:12 -0000 1.12
> +++ video.1 3 Jun 2016 12:21:59 -0000
> @@ -25,7 +25,7 @@
> .Sh SYNOPSIS
> .Nm
> .Bk -words
> -.Op Fl \&gRv
> +.Op Fl \&gqRv
> .Op Fl a Ar adaptor
> .Op Fl e Ar encoding
> .Op Fl f Ar file
> @@ -133,6 +133,9 @@ If
> is
> .Ql - ,
> frames will be written to standard output.
> +.It Fl q
> +Query for encodings, frame sizes/rates, and controls.
> +Display them and quit.
> .It Fl R
> Disable frame rate adjustment.
> .It Fl r Ar rate
> Index: video.c
> ===================================================================
> RCS file: /cvs/xenocara/app/video/video.c,v
> retrieving revision 1.16
> diff -u -p -u -p -r1.16 video.c
> --- video.c 2 Jun 2016 08:53:32 -0000 1.16
> +++ video.c 3 Jun 2016 12:21:59 -0000
> @@ -169,6 +169,7 @@ struct video {
> #define M_OUT_XV 0x2
> #define M_IN_FILE 0x4
> #define M_OUT_FILE 0x8
> +#define M_QUERY 0x10
> int mode;
> int verbose;
> };
> @@ -186,6 +187,7 @@ int dev_get_sizes(struct video *);
> int dev_get_rates(struct video *);
> int dev_get_ctrls(struct video *);
> void dev_dump_info(struct video *);
> +void dev_dump_query(struct video *);
> int dev_init(struct video *);
> void dev_set_ctrl(struct video *, int, int);
> void dev_reset_ctrls(struct video *);
> @@ -213,7 +215,7 @@ extern char *__progname;
> void
> usage(void)
> {
> - fprintf(stderr, "usage: %s [-gRv] "
> + fprintf(stderr, "usage: %s [-gqRv] "
> "[-a adaptor] [-e encoding] [-f file] [-i input] [-O output]\n"
> " %*s [-o output] [-r rate] [-s size]\n", __progname,
> (int)strlen(__progname), "");
> @@ -1024,6 +1026,24 @@ dev_dump_info(struct video *vid)
> fprintf(stderr, "\n");
> }
>
> +void
> +dev_dump_query(struct video *vid)
> +{
> + if (!dev_check_caps(vid))
> + return;
> + if (!dev_get_encs(vid))
> + return;
> + if (!choose_enc(vid))
> + return;
> + if (!dev_get_sizes(vid))
> + return;
> + if (!dev_get_rates(vid))
> + return;
> + if (!dev_get_ctrls(vid))
> + return;
> + dev_dump_info(vid);
> +}
> +
> int
> dev_init(struct video *vid)
> {
> @@ -1757,7 +1777,7 @@ main(int argc, char *argv[])
> vid.mmap_on = 1; /* mmap method is default */
> wout = 1;
>
> - while ((ch = getopt(argc, argv, "gvRa:e:f:i:O:o:r:s:")) != -1) {
> + while ((ch = getopt(argc, argv, "gqRva:e:f:i:O:o:r:s:")) != -1) {
> switch (ch) {
> case 'a':
> x->cur_adap = strtonum(optarg, 0, 4, &errstr);
> @@ -1802,6 +1822,10 @@ main(int argc, char *argv[])
> optarg);
> }
> break;
> + case 'q':
> + vid.mode |= M_QUERY;
> + vid.mode &= ~M_OUT_XV;
> + break;
> case 'R':
> vid.nofps = 1;
> break;
> @@ -1831,6 +1855,11 @@ main(int argc, char *argv[])
> }
> argc -= optind;
> argv += optind;
> +
> + if (vid.mode & M_QUERY) {
> + dev_dump_query(&vid);
> + cleanup(&vid, 0);
> + }
>
> if (vid.fps == 0)
> vid.nofps = 1;
>
--
Dmitrij D. Czarkoff
