[vlc-devel] [PATCH 1/2] libvlc: add libvlc_media_player_dump

[Thomas Guillem]

On Thu, May 19, 2016, at 17:46, Rémi Denis-Courmont wrote:
> Le 2016-05-19 16:47, Thomas Guillem a écrit :
> > ---
> >  include/vlc/libvlc_media_player.h | 18 ++++++++++++++++++
> >  lib/libvlc.sym                    |  1 +
> >  lib/media_player.c                | 28 ++++++++++++++++++++++++++++
> >  3 files changed, 47 insertions(+)
> >
> > diff --git a/include/vlc/libvlc_media_player.h
> > b/include/vlc/libvlc_media_player.h
> > index 456e99e..7b77af5 100644
> > --- a/include/vlc/libvlc_media_player.h
> > +++ b/include/vlc/libvlc_media_player.h
> > @@ -961,6 +961,24 @@ LIBVLC_API void
> > libvlc_media_player_set_video_title_display( libvlc_media_player
> >   */
> >  LIBVLC_API void libvlc_track_description_list_release(
> > libvlc_track_description_t *p_track_description );
> >
> > +/**
> > + * Dump the media attached to the Media Player into a local file
> > + *
> > + * \note You can't dump if the Media Player is already playing. The 
> > dump is
> > + * done asynchronously. Listen to \ref libvlc_MediaPlayerEndReached 
> > and \ref
> > + * libvlc_MediaPlayerEncounteredError events to be notified when the
> > dump ends.
> > + * You can call libvlc_media_player_stop() to abort the dump.
> > + *
> > + * \version LibVLC 3.0.0 and later.
> > + *
> > + * \param p_mi the Media Player
> > + * \param psz_path local filesystem path where to dump the media
> > + *
> > + * \return -1 if an error was detected, 0 otherwise.
> > + */
> > +LIBVLC_API int libvlc_media_player_dump( libvlc_media_player_t 
> > *p_mi,
> > +                                         const char *psz_path );
> > +
> >  /** \defgroup libvlc_video LibVLC video controls
> >   * @{
> >   */
> > diff --git a/lib/libvlc.sym b/lib/libvlc.sym
> > index 816025d..be6872c 100644
> > --- a/lib/libvlc.sym
> > +++ b/lib/libvlc.sym
> > @@ -149,6 +149,7 @@ libvlc_media_parse
> >  libvlc_media_parse_async
> >  libvlc_media_parse_with_options
> >  libvlc_media_player_can_pause
> > +libvlc_media_player_dump
> >  libvlc_media_player_program_scrambled
> >  libvlc_media_player_next_frame
> >  libvlc_media_player_event_manager
> > diff --git a/lib/media_player.c b/lib/media_player.c
> > index 4761fee..f8aa6d6 100644
> > --- a/lib/media_player.c
> > +++ b/lib/media_player.c
> > @@ -669,6 +669,10 @@ libvlc_media_player_new( libvlc_instance_t 
> > *instance )
> >      var_Create (mp, "equalizer-vlcfreqs", VLC_VAR_BOOL);
> >      var_Create (mp, "equalizer-bands", VLC_VAR_STRING);
> >
> > +    /* Demux (for demuxdump) */
> > +    var_Create (mp, "demux", VLC_VAR_STRING | VLC_VAR_DOINHERIT);
> > +    var_Create (mp, "demuxdump-file", VLC_VAR_STRING | 
> > VLC_VAR_DOINHERIT);
> > +
> >      mp->p_md = NULL;
> >      mp->state = libvlc_NothingSpecial;
> >      mp->p_libvlc_instance = instance;
> > @@ -1014,6 +1018,8 @@ void libvlc_media_player_stop(
> > libvlc_media_player_t *p_mi )
> >
> >      input_resource_Terminate( p_mi->input.p_resource );
> >      unlock_input(p_mi);
> > +
> > +    var_SetString( p_mi, "demux", "" );
> >  }
> >
> >
> > @@ -1856,6 +1862,28 @@ void
> > libvlc_media_player_set_video_title_display( libvlc_media_player_t
> > *p_mi, l
> >      }
> >  }
> >
> > +int libvlc_media_player_dump( libvlc_media_player_t *p_mi, const
> > char *psz_path )
> > +{
> > +    assert( p_mi != NULL && psz_path != NULL );
> > +
> > +    lock_input( p_mi );
> > +    input_thread_t *p_input_thread = p_mi->input.p_thread;
> > +    if( p_input_thread )
> > +    {
> > +        unlock_input( p_mi );
> > +        libvlc_printerr( "can't dump while playing" );
> > +        return -1;
> > +    }
> > +    unlock_input( p_mi );
> > +
> > +    var_SetString( p_mi, "demux", "dump,none" );
> > +    var_SetString( p_mi, "demuxdump-file", psz_path );
> > +
> > +    int i_ret = libvlc_media_player_play( p_mi );
> > +    if (i_ret != 0)
> > +        var_SetString( p_mi, "demux", "" );
> > +    return i_ret;
> > +}
> >  /**
> >   * Maximum size of a formatted equalizer amplification band 
> > frequency value.
> >   *
> 
> The function seems rather pointless and impractical. And the 
> implementation looks broken and racy.

Pointless, no, this is a very asked feature. Users of VLC ports want to
download their media files to their devices from their media shares.

Racy, ah yes maybe.

Impractical, yes since it's weird to dump a file from a Media Player.

I thought of adding a libvlc_media_player_set_dump_file(p_mi, psz_path)
function.
Then to dump a file, call libvlc_media_player_play() This won't be racy
anymore, but still weird to use.

Maybe we should create a new dumper "class".

> 
> -- 
> Rémi Denis-Courmont
> http://www.remlab.net/
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