[vlc-devel] [PATCH] Merge VoD module into RTP stream output module

[Rémi Denis-Courmont]

On Fri, 29 Oct 2010 04:01:28 +0200, Pierre Ynard <linkfanel at yahoo.fr>
wrote:
> @@ -445,7 +462,43 @@ static int Open( vlc_object_t *p_this )
>      free (psz);
>      var_Create (p_this, "dccp-service", VLC_VAR_STRING);
>  
> -    if( ( p_sys->psz_destination == NULL ) && !b_rtsp )
> +    int64_t i_pts_init;
> +    p_sys->p_vod_media = NULL;
> +    p_sys->psz_vod_session = NULL;
> +
> +    if (! strcmp(p_stream->psz_name, "vod"))
> +    {

Why is this not a different Open callback altogether??

> +        /* The VLM stops all instances before deleting a media, so this
> +         * reference will remain valid during the lifetime of the rtp
> +         * stream output. */
> +        p_sys->p_vod_media = var_InheritAddress(p_stream, "vod-media");
> +
> +        if (p_sys->p_vod_media != NULL)
> +        {
> +            p_sys->psz_vod_session = var_InheritString(p_stream,
> "vod-session");
> +            if (p_sys->psz_vod_session == NULL)
> +            {
> +                msg_Err(p_stream, "missing VoD session");
> +                free(p_sys);
> +                return VLC_EGENERIC;
> +            }
> +
> +            const char *mux;
> +            if (vod_get_sout_info(p_sys->p_vod_media,
> p_sys->psz_vod_session,
> +                                  &mux, &i_pts_init) != VLC_SUCCESS)
> +            {

Why do you need to a specific PTS?

> +                msg_Err(p_stream, "VoD session '%s' is gone, aborting",
> +                        p_sys->psz_vod_session);
> +                free(p_sys->psz_vod_session);
> +                free(p_sys);
> +                return VLC_EGENERIC;
> +            }
> +            var_SetString(p_stream, SOUT_CFG_PREFIX "mux", mux);
> +        }
> +    }
> +
> +    if( p_sys->psz_destination == NULL && !b_rtsp
> +        && p_sys->p_vod_media == NULL )
>      {
>          msg_Err( p_stream, "missing destination and not in RTSP mode" );
>          free( p_sys );

(...)

> +        if (val == VLC_SUCCESS)
> +        {
> +            memcpy(id->ssrc, &ssrc, sizeof(id->ssrc));
> +            /* This is ugly, but id->i_seq_sent_next needs to be
> +             * initialized inside vod_init_id() to avoid race
> +             * conditions. */
> +            id->i_sequence = id->i_seq_sent_next;
> +        }
> +
> +        /* XXX: It might happen that the VoD media gives us a dynamic
> +         * payload type that is already in use in p_sys->payload_bitmap,
> +         * because it was taken by a previous ES that was missing in
> +         * the VoD media. */

This is a silly problem. Payload types are scoped to the RTP session / the
SDP m-line. Since VLC never streams more than one payload format per RTP
stream, there is no risk of conflict. We might as well hard-code value 96
for all dynamic payload types.

> +        /* vod_init_id() may fail either because the ES wasn't found in
> +         * the VoD media, or because that track wasn't SETUP. In the
> +         * former case, id->rtp_fmt was left untouched, so we fill it
> +         * in right after this. */
> +    }
> +
> +    if (id->rtp_fmt.ptname == NULL)

How can this even happen?! All payload types have specified names, even
static ones.

(...)

> +void rtp_get_fmt( vlc_object_t *obj, es_format_t *p_fmt, const char
*mux,
> +                  rtp_format_t *rtp_fmt )
> +{
> +    assert( p_fmt != NULL || mux != NULL );
> +
> +    rtp_fmt->payload_type = 96; /* dynamic payload type */
> +    rtp_fmt->ptname = NULL;
> +    rtp_fmt->cat = mux != NULL ? VIDEO_ES : p_fmt->i_cat;
> +    if( rtp_fmt->cat == AUDIO_ES )
> +    {
> +        rtp_fmt->clock_rate = p_fmt->audio.i_rate;
> +        rtp_fmt->channels = p_fmt->audio.i_channels;
> +    }
> +    else
> +        rtp_fmt->clock_rate = 90000; /* most common case for video */
> +    /* Stream bitrate in kbps */
> +    rtp_fmt->bitrate = p_fmt != NULL ? p_fmt->i_bitrate/1000 : 0;
> +    rtp_fmt->fmtp = NULL;
> +
> +    if( mux != NULL )
> +    {
> +        if( strncmp( mux, "ts", 2 ) == 0 )
> +        {
> +            rtp_fmt->payload_type = 33;
> +            rtp_fmt->ptname = "MP2T";
> +        }
> +        else
> +            rtp_fmt->ptname = "MP2P";
> +        return;
> +    }
> +
[very big switch]

We really need a new plugin layer for RTp packetization :-( but that's a
separate problem.

-- 
Rémi Denis-Courmont
http://www.remlab.net
http://fi.linkedin.com/in/remidenis