[vlc-devel] [PATCH 08/48] video_output: add vout_GetDevice to get the vout decoder device on demand

[Rémi Denis-Courmont]

Le perjantaina 11. lokakuuta 2019, 16.33.22 EEST Steve Lhomme a écrit :
> Only a few decoders will request it.
> 
> A decoder device can only be created if the vout has an enabled window.
> 
> The caller receives a reference to the decoder device or NULL.
> ---
>  src/video_output/video_output.c  | 31 ++++++++++++++++++++++++++++---
>  src/video_output/vout_internal.h | 10 ++++++++++
>  2 files changed, 38 insertions(+), 3 deletions(-)
> 
> diff --git a/src/video_output/video_output.c
> b/src/video_output/video_output.c index 2a6ca6fefab..b7452967ec0 100644
> --- a/src/video_output/video_output.c
> +++ b/src/video_output/video_output.c
> @@ -49,6 +49,7 @@
>  #include <vlc_vout_osd.h>
>  #include <vlc_image.h>
>  #include <vlc_plugin.h>
> +#include <vlc_codec.h>
> 
>  #include <libvlc.h>
>  #include "vout_internal.h"
> @@ -1744,6 +1745,11 @@ static void vout_DisableWindow(vout_thread_t *vout)
>  {
>      vout_thread_sys_t *sys = vout->p;
>      vlc_mutex_lock(&sys->window_lock);
> +    if (sys->dec_device)
> +    {
> +        vlc_decoder_device_Release(sys->dec_device);
> +        sys->dec_device = NULL;
> +    }
>      if (sys->window_enabled) {
>          vout_window_Disable(sys->display_cfg.window);
>          sys->window_enabled = false;
> @@ -1801,6 +1807,9 @@ void vout_Release(vout_thread_t *vout)
>      vlc_mutex_destroy(&vout->p->window_lock);
>      vlc_mutex_destroy(&vout->p->filter.lock);
> 
> +    if (sys->dec_device)
> +        vlc_decoder_device_Release(sys->dec_device);
> +
>      assert(!sys->window_enabled);
>      vout_display_window_Delete(sys->display_cfg.window);
> 
> @@ -1932,7 +1941,7 @@ vout_thread_t *vout_Hold(vout_thread_t *vout)
>      return vout;
>  }
> 
> -static int vout_EnableWindow(const vout_configuration_t *cfg)
> +static int vout_EnableWindow(const vout_configuration_t *cfg,
> vlc_decoder_device **pp_dec_device) {
>      vout_thread_t *vout = cfg->vout;
>      vout_thread_sys_t *sys = vout->p;
> @@ -1955,6 +1964,8 @@ static int vout_EnableWindow(const
> vout_configuration_t *cfg) if (cfg->dpb_size <= sys->dpb_size) {
>              video_format_Clean(&original);
>              /* It is assumed that the SPU input matches input already. */
> +            if (pp_dec_device)
> +                *pp_dec_device = sys->dec_device ? vlc_decoder_device_Hold(
> sys->dec_device ) : NULL; return 0;
>          }
>          msg_Warn(vout, "DPB need to be increased");
> @@ -1991,8 +2002,14 @@ static int vout_EnableWindow(const
> vout_configuration_t *cfg) sys->window_enabled = true;
>      } else
>          vout_UpdateWindowSizeLocked(vout);
> -    vlc_mutex_unlock(&sys->window_lock);
> 
> +    if (pp_dec_device)
> +    {
> +        if (sys->dec_device == NULL)
> +            sys->dec_device =
> vlc_decoder_device_Create(sys->display_cfg.window); +        *pp_dec_device
> = sys->dec_device ? vlc_decoder_device_Hold( sys->dec_device ) : NULL; +   
> }
> +    vlc_mutex_unlock(&sys->window_lock);
>      return 0;
>  }
> 
> @@ -2001,7 +2018,7 @@ int vout_Request(const vout_configuration_t *cfg,
> input_thread_t *input) vout_thread_t *vout = cfg->vout;
>      vout_thread_sys_t *sys = vout->p;
> 
> -    if (vout_EnableWindow(cfg) != 0)
> +    if (vout_EnableWindow(cfg, NULL) != 0)
>          return -1;
> 
>      sys->delay = 0;
> @@ -2027,3 +2044,11 @@ int vout_Request(const vout_configuration_t *cfg,
> input_thread_t *input) vout_IntfReinit(vout);
>      return 0;
>  }
> +
> +vlc_decoder_device *vout_GetDevice(const vout_configuration_t *cfg)
> +{
> +    vlc_decoder_device *dec_device = NULL;
> +    if (vout_EnableWindow(cfg, &dec_device) != 0)
> +        return NULL;
> +    return dec_device;
> +}
> diff --git a/src/video_output/vout_internal.h
> b/src/video_output/vout_internal.h index 29f2144f82b..30f79794e12 100644
> --- a/src/video_output/vout_internal.h
> +++ b/src/video_output/vout_internal.h
> @@ -173,6 +173,7 @@ struct vout_thread_sys_t
>      /* Video output window */
>      bool            window_enabled;
>      vlc_mutex_t     window_lock;
> +    vlc_decoder_device *dec_device;
> 
>      /* Video output display */
>      vout_display_cfg_t display_cfg;
> @@ -195,6 +196,14 @@ vout_thread_t *vout_Create(vlc_object_t *obj) VLC_USED;
> 
>  vout_thread_t *vout_CreateDummy(vlc_object_t *obj) VLC_USED;
> 
> +/**
> + * Setup the vout for the given configuration and get an associated decoder
> device. + *
> + * \param cfg the video configuration requested.
> + * \return pointer to a decoder device reference to use with the vout or
> NULL + */
> +vlc_decoder_device *vout_GetDevice(const vout_configuration_t *cfg);
> +
>  /**
>   * Returns a suitable vout or release the given one.
>   *
> @@ -206,6 +215,7 @@ vout_thread_t *vout_CreateDummy(vlc_object_t *obj)
> VLC_USED; *
>   * \param cfg the video configuration requested.
>   * \param input used to get attachments for spu filters
> + * \param dec_dev pointer to receive the decoder device reference to use
> with the vout or NULL * \retval 0 on success
>   * \retval -1 on error
>   */

vout_configuration_t is not really conceptually suitable to span more than one 
function call. In fact, cfg.vout can be NULL (still in some contexts), and 
then obviously this wouldn't work.

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