[vlc-devel] [vlc-commits] Add NTSC EIA-608 caption rendering support via V4L2 VBI devices

[Rafaël Carré]

Hello,

Le 10/12/2012 17:11, Devin Heitmueller a écrit :
> vlc | branch: master | Devin Heitmueller <dheitmueller at kernellabs.com> | Mon Dec 10 11:02:07 2012 -0500| [bf4eb0941758ec544c6e4911414bdfdf263a3ea6] | committer: Rémi Denis-Courmont
> 
> Add NTSC EIA-608 caption rendering support via V4L2 VBI devices
> 
> This patch introduces support for using V4L2 VBI devices for
> reading NTSC EIA-608 closed captions.
> 
> This patch includes feedback from the vlc-devel mailing list from
> the Oct 21, 2012, Oct 28, 2012, and Nov 18, 2012 submission attempts.
> 
> Signed-off-by: Rémi Denis-Courmont <remi at remlab.net>
> 
>> http://git.videolan.org/gitweb.cgi/vlc.git/?a=commit;h=bf4eb0941758ec544c6e4911414bdfdf263a3ea6
> ---
> 
>  modules/access/Modules.am    |    5 +-
>  modules/access/v4l2/access.c |    3 +-
>  modules/access/v4l2/demux.c  |  194 ++++++++++++++++++++++++++++++++----------
>  modules/access/v4l2/v4l2.c   |    8 ++
>  modules/access/v4l2/v4l2.h   |   14 ++-
>  modules/access/v4l2/vbi.c    |  131 ++++++++++++++++++++++++++++
>  modules/access/v4l2/video.c  |   21 +++--
>  7 files changed, 320 insertions(+), 56 deletions(-)

+    for (int i = 0; i < VBI_NUM_CC_STREAMS; i++)
+    {
+        es_format_t fmt;
+
+        es_format_Init( &fmt, SPU_ES, VLC_FOURCC('c', 'c', '1' + i, ' ') );
+        if (asprintf(&fmt.psz_description, "Closed captions %d", i + 1)
>= 0)
+        {
+            msg_Dbg( demux, "new spu es %4.4s", (char*)&fmt.i_codec );
+            sys->p_es_subt[i] = es_out_Add( demux->out, &fmt );
+        }
+    }

You declare 4 streams,

+    {
+        for (int i = 0; i < num_streams; i++)
+        {
+            block_t *p_sblock;
+            if (p_es_subt[i] == NULL)
+                continue;
+            p_sblock = block_Duplicate(p_block);
+            if (p_sblock)
+                es_out_Send(p_demux->out, p_es_subt[i], p_sblock);
+        }
+        block_Release(p_block);

num_streams = VBI_NUM_CC_STREAMS = 4

But you will just duplicate the same information 4 times.

Why duplicating at all?