[vlc-devel] [RFC 5/8] libvlc: pass the video output callbacks using a structure
Thomas Guillem
thomas at gllm.fr
Tue Nov 20 17:21:04 CET 2018
On Tue, Nov 20, 2018, at 17:19, Jean-Baptiste Kempf wrote:
> I am not sure if that is wise, wrt ABI/API.
It is since the struct is created by LibVLC.
>
> Thomas, Rémi?
>
> On Tue, 20 Nov 2018, at 16:42, Steve Lhomme wrote:
> > This way it can be expanded in the future without changing existing code.
> >
> > The engine is put with the callback. Maybe at some point it should be possible
> > to set callbacks per engine and have all of them used depending on what the vout
> > is in use.
> > ---
> > doc/libvlc/sdl_opengl_player.cpp | 16 +++++--
> > include/vlc/libvlc_media_player.h | 77 ++++++++++++++++++++++---------
> > lib/libvlc.sym | 2 +
> > lib/media_player.c | 43 +++++++++--------
> > 4 files changed, 93 insertions(+), 45 deletions(-)
> >
> > diff --git a/doc/libvlc/sdl_opengl_player.cpp b/doc/libvlc/
> > sdl_opengl_player.cpp
> > index dabc430bdd..80d66178ae 100644
> > --- a/doc/libvlc/sdl_opengl_player.cpp
> > +++ b/doc/libvlc/sdl_opengl_player.cpp
> > @@ -78,11 +78,19 @@ public:
> > libvlc_media_release(m_media);
> > return false;
> > }
> > +
> > + libvlc_video_engine_callbacks_t *callbacks =
> > +
> > libvlc_video_engine_callbacks_get( libvlc_video_engine_opengl );
> > + callbacks->opaque = this;
> > + callbacks->setup_cb = setup;
> > + callbacks->cleanup_cb = cleanup;
> > + callbacks->update_output_cb = resize;
> > + callbacks->swap_cb = swap;
> > + callbacks->makeCurrent_cb = make_current;
> > + callbacks->getProcAddress_cb = get_proc_address;
> > +
> > // Define the opengl rendering callbacks
> > - libvlc_video_set_output_callbacks(m_mp,
> > libvlc_video_engine_opengl,
> > - setup, cleanup, resize, swap,
> > - make_current, get_proc_address,
> > - this);
> > + libvlc_video_set_output_callbacks(m_mp, callbacks);
> >
> > // Play the video
> > libvlc_media_player_play (m_mp);
> > diff --git a/include/vlc/libvlc_media_player.h b/include/vlc/
> > libvlc_media_player.h
> > index 45cd47afac..9158fc328b 100644
> > --- a/include/vlc/libvlc_media_player.h
> > +++ b/include/vlc/libvlc_media_player.h
> > @@ -425,7 +425,7 @@ void
> > libvlc_video_set_callbacks( libvlc_media_player_t *mp,
> > /**
> > * Callback prototype called to initialize user data.
> > *
> > - * \param opaque private pointer passed to the @a
> > libvlc_video_set_output_callbacks() [IN]
> > + * \param opaque private pointer passed in the @a
> > libvlc_video_engine_callbacks_t [IN]
> > * \return true on success
> > * \version LibVLC 4.0.0 or later
> > */
> > @@ -435,7 +435,7 @@ typedef bool (*libvlc_video_setup_cb)(void* opaque);
> > /**
> > * Callback prototype called to release user data
> > *
> > - * \param opaque private pointer passed to the @a
> > libvlc_video_set_output_callbacks() [IN]
> > + * \param opaque private pointer passed in the @a
> > libvlc_video_engine_callbacks_t [IN]
> > * \version LibVLC 4.0.0 or later
> > */
> > typedef void (*libvlc_video_cleanup_cb)(void* opaque);
> > @@ -443,7 +443,7 @@ typedef void (*libvlc_video_cleanup_cb)(void*
> > opaque);
> > /**
> > * Callback prototype called on video size changes
> > *
> > - * \param opaque private pointer passed to the @a
> > libvlc_video_set_output_callbacks() [IN]
> > + * \param opaque private pointer passed in the @a
> > libvlc_video_engine_callbacks_t [IN]
> > * \param width video width in pixel [IN]
> > * \param height video height in pixel [IN]
> > * \return true on success
> > @@ -455,7 +455,7 @@ typedef bool (*libvlc_video_update_output_cb)(void*
> > opaque, unsigned width, unsi
> > /**
> > * Callback prototype called after performing drawing calls.
> > *
> > - * \param opaque private pointer passed to the @a
> > libvlc_video_set_output_callbacks() [IN]
> > + * \param opaque private pointer passed in the @a
> > libvlc_video_engine_callbacks_t [IN]
> > * \version LibVLC 4.0.0 or later
> > */
> > typedef void (*libvlc_video_swap_cb)(void* opaque);
> > @@ -463,7 +463,7 @@ typedef void (*libvlc_video_swap_cb)(void* opaque);
> > /**
> > * Callback prototype to set up the OpenGL context for rendering
> > *
> > - * \param opaque private pointer passed to the @a
> > libvlc_video_set_output_callbacks() [IN]
> > + * \param opaque private pointer passed in the @a
> > libvlc_video_engine_callbacks_t [IN]
> > * \param enter true to set the context as current, false to unset it
> > [IN]
> > * \return true on success
> > * \version LibVLC 4.0.0 or later
> > @@ -473,7 +473,7 @@ typedef bool (*libvlc_video_makeCurrent_cb)(void*
> > opaque, bool enter);
> > /**
> > * Callback prototype to load opengl functions
> > *
> > - * \param opaque private pointer passed to the @a
> > libvlc_video_set_output_callbacks() [IN]
> > + * \param opaque private pointer passed in the @a
> > libvlc_video_engine_callbacks_t [IN]
> > * \param fct_name name of the opengl function to load
> > * \return a pointer to the named OpenGL function the NULL otherwise
> > * \version LibVLC 4.0.0 or later
> > @@ -490,34 +490,67 @@ typedef enum libvlc_video_engine_t {
> > } libvlc_video_engine_t;
> >
> > /**
> > - * Set callbacks and data to render decoded video to a custom texture
> > + * The structure should be created by
> > libvlc_video_engine_callbacks_get().
> > *
> > - * \warning VLC will perform video rendering in its own thread and at
> > its own rate,
> > - * You need to provide your own synchronisation mechanism.
> > - *
> > - * OpenGL context need to be created before playing a media.
> > - *
> > - * \param mp the media player
> > * \param engine the GPU engine to use
> > + * \param opaque private pointer passed to each callbacks
> > * \param setup_cb callback called to initialize user data
> > * \param cleanup_cb callback called to clean up user data
> > * \param update_output_cb callback called to get the size of the video
> > * \param swap_cb callback called after rendering a video frame (cannot
> > be NULL)
> > * \param makeCurrent_cb callback called to enter/leave the opengl
> > context (cannot be NULL)
> > * \param getProcAddress_cb opengl function loading callback (cannot be
> > NULL)
> > - * \param opaque private pointer passed to callbacks
> > + * \version LibVLC 4.0.0 or later
> > + */
> > +typedef struct libvlc_video_engine_callbacks_t
> > +{
> > + libvlc_video_engine_t engine;
> > +
> > + void *opaque;
> > +
> > + libvlc_video_setup_cb setup_cb;
> > + libvlc_video_cleanup_cb cleanup_cb;
> > + libvlc_video_update_output_cb update_output_cb;
> > + libvlc_video_swap_cb swap_cb;
> > +
> > + /* OpenGL/GLES2 specific callbacks */
> > + libvlc_video_makeCurrent_cb makeCurrent_cb;
> > + libvlc_video_getProcAddress_cb getProcAddress_cb;
> > +} libvlc_video_engine_callbacks_t;
> > +
> > +/**
> > + * Initialize a libvlc_video_engine_callbacks_t structure.
> > + *
> > + * \param engine the engine to initialize the callbacks for.
> > + * \return a libvlc_video_engine_callbacks_t structure or NULL
> > + */
> > +LIBVLC_API
> > +libvlc_video_engine_callbacks_t *libvlc_video_engine_callbacks_get(
> > + libvlc_video_engine_t engine );
> > +
> > +/**
> > + * Release (free) libvlc_video_engine_callbacks_t
> > + *
> > + * \param cb the structure to release
> > + */
> > +LIBVLC_API
> > +void
> > libvlc_video_engine_callbacks_release( libvlc_video_engine_callbacks_t
> > *cb );
> > +
> > +/**
> > + * Set callbacks and data to render decoded video to a custom texture
> > + *
> > + * \warning VLC will perform video rendering in its own thread and at
> > its own rate,
> > + * You need to provide your own synchronisation mechanism.
> > + *
> > + * OpenGL context need to be created before playing a media.
> > + *
> > + * \param mp the media player
> > + * \param callbacks the callbacks to use for the given engine.
> > * \version LibVLC 4.0.0 or later
> > */
> > LIBVLC_API
> > void libvlc_video_set_output_callbacks( libvlc_media_player_t *mp,
> > - libvlc_video_engine_t engine,
> > - libvlc_video_setup_cb setup_cb,
> > - libvlc_video_cleanup_cb
> > cleanup_cb,
> > - libvlc_video_update_output_cb
> > update_output_cb,
> > - libvlc_video_swap_cb swap_cb,
> > - libvlc_video_makeCurrent_cb
> > makeCurrent_cb,
> > - libvlc_video_getProcAddress_cb
> > getProcAddress_cb,
> > - void* opaque );
> > + libvlc_video_engine_callbacks_t
> > *callbacks );
> >
> > /**
> > * Set decoded video chroma and dimensions.
> > diff --git a/lib/libvlc.sym b/lib/libvlc.sym
> > index 285cf4f7af..042f79b279 100644
> > --- a/lib/libvlc.sym
> > +++ b/lib/libvlc.sym
> > @@ -246,6 +246,8 @@ libvlc_video_set_crop_geometry
> > libvlc_video_set_deinterlace
> > libvlc_video_set_format
> > libvlc_video_set_format_callbacks
> > +libvlc_video_engine_callbacks_get
> > +libvlc_video_engine_callbacks_release
> > libvlc_video_set_output_callbacks
> > libvlc_video_set_key_input
> > libvlc_video_set_logo_int
> > diff --git a/lib/media_player.c b/lib/media_player.c
> > index 89ba10d638..ef9bc329fd 100644
> > --- a/lib/media_player.c
> > +++ b/lib/media_player.c
> > @@ -98,10 +98,10 @@ static void
> > libvlc_media_player_destroy( libvlc_media_player_t *p_mi );
> >
> > /*
> > * The input lock protects the input and input resource pointer.
> > - * It MUST NOT be used from callbacks.
> > + * It MUST NOT be used from callbacks->
> > *
> > * The object lock protects the reset, namely the media and the player
> > state.
> > - * It can, and usually needs to be taken from callbacks.
> > + * It can, and usually needs to be taken from callbacks->
> > * The object lock can be acquired under the input lock... and
> > consequently
> > * the opposite order is STRICTLY PROHIBITED.
> > */
> > @@ -413,7 +413,7 @@ input_event_changed( vlc_object_t * p_this, char
> > const * psz_cmd,
> > else if ( newval.i_int == INPUT_EVENT_ES )
> > {
> > /* Send ESSelected events from this callback ("intf-event") and
> > not
> > - * from "audio-es", "video-es", "spu-es" callbacks. Indeed,
> > these
> > + * from "audio-es", "video-es", "spu-es" callbacks-> Indeed,
> > these
> > * callbacks are not triggered when the input_thread changes an
> > ES
> > * while this callback is. */
> > struct {
> > @@ -1161,14 +1161,7 @@ void
> > libvlc_video_set_format( libvlc_media_player_t *mp, const char *chroma,
> > }
> >
> > void libvlc_video_set_output_callbacks( libvlc_media_player_t *mp,
> > - libvlc_video_engine_t engine,
> > - libvlc_video_setup_cb setup_cb,
> > - libvlc_video_cleanup_cb
> > cleanup_cb,
> > - libvlc_video_update_output_cb
> > update_output_cb,
> > - libvlc_video_swap_cb swap_cb,
> > - libvlc_video_makeCurrent_cb
> > makeCurrent_cb,
> > - libvlc_video_getProcAddress_cb
> > getProcAddress_cb,
> > - void* opaque )
> > + libvlc_video_engine_callbacks_t
> > *callbacks )
> > {
> > #ifdef __ANDROID__
> > //use the default android window
> > @@ -1177,7 +1170,7 @@ void
> > libvlc_video_set_output_callbacks( libvlc_media_player_t *mp,
> > var_SetString( mp, "window", "wdummy");
> > #endif
> >
> > - if( engine == libvlc_video_engine_gles2 )
> > + if( callbacks->engine == libvlc_video_engine_gles2 )
> > {
> > var_SetString ( mp, "vout", "gles2" );
> > var_SetString ( mp, "gles2", "vgl" );
> > @@ -1188,15 +1181,27 @@ void
> > libvlc_video_set_output_callbacks( libvlc_media_player_t *mp,
> > var_SetString ( mp, "gl", "vgl");
> > }
> >
> > - var_SetAddress( mp, "vout-cb-opaque", opaque );
> > - var_SetAddress( mp, "vout-cb-setup", setup_cb );
> > - var_SetAddress( mp, "vout-cb-cleanup", cleanup_cb );
> > - var_SetAddress( mp, "vout-cb-update-output", update_output_cb );
> > - var_SetAddress( mp, "vout-cb-swap", swap_cb );
> > - var_SetAddress( mp, "vout-cb-get-proc-address",
> > getProcAddress_cb );
> > - var_SetAddress( mp, "vout-cb-make-current", makeCurrent_cb );
> > + var_SetAddress( mp, "vout-cb-opaque", callbacks->opaque );
> > + var_SetAddress( mp, "vout-cb-setup", callbacks->setup_cb );
> > + var_SetAddress( mp, "vout-cb-cleanup", callbacks->cleanup_cb );
> > + var_SetAddress( mp, "vout-cb-update-output", callbacks-
> > >update_output_cb );
> > + var_SetAddress( mp, "vout-cb-swap", callbacks->swap_cb );
> > + var_SetAddress( mp, "vout-cb-get-proc-address", callbacks-
> > >getProcAddress_cb );
> > + var_SetAddress( mp, "vout-cb-make-current", callbacks-
> > >makeCurrent_cb );
> > }
> >
> > +libvlc_video_engine_callbacks_t
> > *libvlc_video_engine_callbacks_get( libvlc_video_engine_t engine )
> > +{
> > + libvlc_video_engine_callbacks_t *callbacks = calloc(1,
> > sizeof(*callbacks));
> > + if (callbacks)
> > + callbacks->engine = engine;
> > + return callbacks;
> > +}
> > +
> > +void
> > libvlc_video_engine_callbacks_release(libvlc_video_engine_callbacks_t *
> > cb)
> > +{
> > + free(cb);
> > +}
> >
> > /**************************************************************************
> > * set_nsobject
> > --
> > 2.17.1
> >
> > _______________________________________________
> > vlc-devel mailing list
> > To unsubscribe or modify your subscription options:
> > https://mailman.videolan.org/listinfo/vlc-devel
>
>
> --
> Jean-Baptiste Kempf - President
> +33 672 704 734
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