[vlc-devel] [RFC 1/6] libvlc: add rendering callbacks for D3D11 and D3D9

Rémi Denis-Courmont remi at remlab.net
Tue Apr 30 18:41:46 CEST 2019


Le mardi 30 avril 2019, 12:34:33 EEST Steve Lhomme a écrit :
> ---
>  include/vlc/libvlc_media_player.h | 143 ++++++++++++++++++++++++++++++
>  lib/libvlc.sym                    |   1 +
>  lib/media_player.c                |  39 ++++++++
>  3 files changed, 183 insertions(+)
> 
> diff --git a/include/vlc/libvlc_media_player.h
> b/include/vlc/libvlc_media_player.h index ca72a550d3..51dd964600 100644
> --- a/include/vlc/libvlc_media_player.h
> +++ b/include/vlc/libvlc_media_player.h
> @@ -557,6 +557,149 @@ int libvlc_video_set_output_callbacks(
> libvlc_media_player_t *mp, libvlc_video_getProcAddress_cb
> getProcAddress_cb, void* opaque );
> 
> +
> +/**
> + * Enumeration of the Video engine to be used on output.
> + * can be passed to @a libvlc_video_set_rendering_callbacks
> + */
> +typedef enum libvlc_video_rendering_t {
> +    /** Direct3D11 rendering engine */
> +    libvlc_video_rendering_direct3d11,
> +    /** Direct3D9 rendering engine */
> +    libvlc_video_rendering_direct3d9,
> +} libvlc_video_rendering_t;
> +
> +typedef struct
> +{
> +    unsigned width;     /** rendering video width in pixel */
> +    unsigned height;    /** rendering video height in pixel */
> +} libvlc_video_callback_setup_t;
> +
> +/**
> + * List of control passed to the @a libvlc_video_control_cb callback
> + */
> +typedef enum libvlc_video_callback_control_t {
> +    /** Setup the rendering environment.
> +     *
> +     * \ref input ignored
> +     * \ref output pointer depending on the type of the engine
> +     *
> +     * For \ref libvlc_video_rendering_direct3d9 the output must be a
> IDirect3DDevice9*. +     * A reference to this object is held until the
> \ref LIBVLC_VIDEO_DEVICE_CLEANUP is called. +     * the device must be
> created with D3DPRESENT_PARAMETERS.hDeviceWindow set to 0. +     *
> +     * For \ref libvlc_video_rendering_direct3d11 the output must be a
> ID3D11DeviceContext*. +     * A reference to this object is held until the
> \ref LIBVLC_VIDEO_DEVICE_CLEANUP is called. +     * The ID3D11Device used
> to create ID3D11DeviceContext must have multithreading enabled. +     */
> +    LIBVLC_VIDEO_DEVICE_SETUP,
> +
> +    /** Cleanup the rendering environment initialized during \ref
> LIBVLC_VIDEO_DEVICE_SETUP. +     *
> +     * \ref input ignored
> +     * \ref output ignored
> +     */
> +    LIBVLC_VIDEO_DEVICE_CLEANUP,
> +
> +    /** Update the rendering output setup.
> +     *
> +     * \ref input const libvlc_video_callback_setup_t* with the new setup
> +     * \ref output ignored
> +     */
> +    LIBVLC_VIDEO_UPDATE_OUTPUT,
> +
> +    /** Callback prototype called after performing drawing calls.
> +     *
> +     * \ref input ignored
> +     * \ref output ignored
> +     */
> +    LIBVLC_VIDEO_SWAP,
> +
> +    /** Tell the host the rendering is about to start.
> +     *
> +     * \ref input ignored
> +     * \ref output ignored
> +     *
> +     * Between \ref LIBVLC_VIDEO_START_RENDERING and \ref
> LIBVLC_VIDEO_FINISHED_RENDERING +     * of Direct3D9 the following may
> change on the provided IDirect3DDevice9*: +     * - D3DSAMP_ADDRESSU
> +     * - D3DSAMP_ADDRESSV
> +     * - D3DSAMP_MINFILTER
> +     * - D3DSAMP_MAGFILTER
> +     * - D3DRS_AMBIENT
> +     * - D3DRS_CULLMODE
> +     * - D3DRS_ZENABLE
> +     * - D3DRS_LIGHTING
> +     * - D3DRS_DITHERENABLE
> +     * - D3DRS_STENCILENABLE
> +     * - D3DRS_ALPHABLENDENABLE
> +     * - D3DRS_SRCBLEND,D3DBLEND_SRCALPHA
> +     * - D3DRS_DESTBLEND,D3DBLEND_INVSRCALPHA
> +     * - D3DPCMPCAPS_GREATER
> +     * - D3DRS_ALPHATESTENABLE
> +     * - D3DRS_ALPHAREF
> +     * - D3DRS_ALPHAFUNC
> +     * - D3DTSS_COLOROP
> +     * - D3DTSS_COLORARG1
> +     * - D3DTSS_ALPHAOP
> +     * - D3DTSS_ALPHAARG1
> +     * - D3DTSS_ALPHAARG2
> +     *
> +     * Between \ref LIBVLC_VIDEO_START_RENDERING and \ref
> LIBVLC_VIDEO_FINISHED_RENDERING +     * of Direct3D11 the following may
> change on the provided ID3D11DeviceContext*: +     * -
> IASetPrimitiveTopology()
> +     * - IASetInputLayout()
> +     * - IASetVertexBuffers()
> +     * - IASetIndexBuffer()
> +     * - VSSetConstantBuffers()
> +     * - VSSetShader()
> +     * - PSSetSamplers()
> +     * - PSSetConstantBuffers()
> +     * - PSSetShaderResources()
> +     * - PSSetShader()
> +     * - RSSetViewports()
> +     * - DrawIndexed()
> +     */
> +    LIBVLC_VIDEO_START_RENDERING,
> +
> +    /** Tell the host the rendering has ended.
> +     *
> +     * \ref input ignored
> +     * \ref output ignored
> +     */
> +    LIBVLC_VIDEO_FINISHED_RENDERING,
> +} libvlc_video_callback_control_t;
> +
> +/**
> + * Callback prototype for the @a libvlc_video_set_surface_callbacks
> callback. + *
> + * \param opaque private pointer passed to the @a
> libvlc_video_set_surface_callbacks() [IN] + * \version LibVLC 4.0.0 or
> later
> + */
> +typedef int (*libvlc_video_control_cb)(void* opaque,
> +                                       libvlc_video_callback_control_t
> control, +                                       const void *input,
> +                                       void **output);

I really don't think that a type-unsafe API is a good idea for LibVLC. It's 
already hard enough to get right.

> +
> +/**
> + * Set callbacks and data to render decoded video to a custom Direct3D
> output + *
> + * \warning VLC will perform video rendering in its own thread and at its
> own rate, + * You need to provide your own synchronisation mechanism.
> + *
> + * \param mp the media player
> + * \param engine the GPU engine to use
> + * \param control_cb callback that receives all the \ref
> libvlc_video_callback_control_t + * \param opaque private pointer passed to
> the control callback
> + * \libvlc_return_bool
> + * \version LibVLC 4.0.0 or later
> + */
> +LIBVLC_API
> +int libvlc_video_set_rendering_callbacks( libvlc_media_player_t *mp,
> +                                          libvlc_video_rendering_t engine,
> +                                          libvlc_video_control_cb
> control_cb, +                                          void* opaque );
> +
>  /**
>   * Set the NSView handler where the media player should render its video
> output. *
> diff --git a/lib/libvlc.sym b/lib/libvlc.sym
> index ef132c37e4..f212088b30 100644
> --- a/lib/libvlc.sym
> +++ b/lib/libvlc.sym
> @@ -244,6 +244,7 @@ libvlc_video_set_deinterlace
>  libvlc_video_set_format
>  libvlc_video_set_format_callbacks
>  libvlc_video_set_output_callbacks
> +libvlc_video_set_rendering_callbacks
>  libvlc_video_set_key_input
>  libvlc_video_set_logo_int
>  libvlc_video_set_logo_string
> diff --git a/lib/media_player.c b/lib/media_player.c
> index 106e7d26b0..e04f1dab19 100644
> --- a/lib/media_player.c
> +++ b/lib/media_player.c
> @@ -646,6 +646,7 @@ libvlc_media_player_new( libvlc_instance_t *instance )
>      var_Create( mp, "vout-cb-swap", VLC_VAR_ADDRESS );
>      var_Create( mp, "vout-cb-get-proc-address", VLC_VAR_ADDRESS );
>      var_Create( mp, "vout-cb-make-current", VLC_VAR_ADDRESS );
> +    var_Create( mp, "vout-cb-control", VLC_VAR_ADDRESS );
> 
>      var_Create (mp, "avcodec-hw", VLC_VAR_STRING);
>      var_Create (mp, "drawable-xid", VLC_VAR_INTEGER);
> @@ -1202,6 +1203,31 @@ int libvlc_video_set_output_callbacks(
> libvlc_media_player_t *mp, }
> 
> 
> +int libvlc_video_set_rendering_callbacks( libvlc_media_player_t *mp,
> +                                        libvlc_video_rendering_t engine,
> +                                        libvlc_video_control_cb control_cb,
> +                                        void* opaque )
> +{
> +    var_SetString( mp, "window", "wdummy");
> +
> +    if ( engine == libvlc_video_rendering_direct3d11 )
> +    {
> +        var_SetString ( mp, "vout", "direct3d11" );
> +        var_SetString ( mp, "avcodec-hw", "d3d11va");
> +    }
> +    else if ( engine == libvlc_video_rendering_direct3d9 )
> +    {
> +        var_SetString ( mp, "vout", "direct3d9" );
> +        var_SetString ( mp, "avcodec-hw", "dxva2");
> +    }
> +    else
> +        return 0;
> +
> +    var_SetAddress( mp, "vout-cb-opaque", opaque );
> +    var_SetAddress( mp, "vout-cb-control", control_cb );
> +    return 1;
> +}
> +
>  /**************************************************************************
> * set_nsobject
>  
> **************************************************************************/
> @@ -2049,3 +2075,16 @@ int
> libvlc_media_player_get_role(libvlc_media_player_t *mp) free(str);
>      return ret;
>  }
> +
> +#include <vlc_vout_display.h>
> +
> +static_assert(VLC_VIDEO_SURFACE_DEVICE_SETUP       ==
> LIBVLC_VIDEO_DEVICE_SETUP && +             
> VLC_VIDEO_SURFACE_DEVICE_CLEANUP     == LIBVLC_VIDEO_DEVICE_CLEANUP && +   
>           VLC_VIDEO_SURFACE_UPDATE_OUTPUT      ==
> LIBVLC_VIDEO_UPDATE_OUTPUT && +              VLC_VIDEO_SURFACE_SWAP        
>       == LIBVLC_VIDEO_SWAP && +             
> VLC_VIDEO_SURFACE_START_RENDERING    == LIBVLC_VIDEO_START_RENDERING && +  
>            VLC_VIDEO_SURFACE_FINISHED_RENDERING ==
> LIBVLC_VIDEO_FINISHED_RENDERING && +             
> sizeof(vlc_video_surface_cfg_t)           ==
> sizeof(libvlc_video_callback_setup_t) && +             
> offsetof(vlc_video_surface_cfg_t, width)  ==
> offsetof(libvlc_video_callback_setup_t, width) && +             
> offsetof(vlc_video_surface_cfg_t, height) ==
> offsetof(libvlc_video_callback_setup_t, height) +              , "video
> surface mismatch");

What's the point of this static assertion? Structures of different types cannot 
alias even if they have the same layout and representation, AFAIK.

-- 
Rémi Denis-Courmont




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