[vlc-devel] [PATCH 08/38] video_output: add vout_GetDevice to get the vout decoder device on demand

[Thomas Guillem]

On Tue, Oct 1, 2019, at 13:12, Steve Lhomme wrote:
> 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  | 32 ++++++++++++++++++++++++++++++++
>  src/video_output/vout_internal.h | 10 ++++++++++
>  2 files changed, 42 insertions(+)
> 
> diff --git a/src/video_output/video_output.c b/src/video_output/video_output.c
> index 131fda74225..dea1141ceae 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"
> @@ -1727,6 +1728,11 @@ void vout_Stop(vout_thread_t *vout)
>          vout_StopDisplay(vout);
>  
>      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;
> @@ -1774,6 +1780,9 @@ 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);
>  
> @@ -1989,6 +1998,11 @@ int vout_Request(const vout_configuration_t 
> *cfg, input_thread_t *input)
>          vlc_mutex_lock(&sys->window_lock);
>          vout_window_Disable(sys->display_cfg.window);
>          sys->window_enabled = false;
> +        if (sys->dec_device)
> +        {
> +            vlc_decoder_device_Release(sys->dec_device);
> +            sys->dec_device = NULL;
> +        }
>          vlc_mutex_unlock(&sys->window_lock);
>          goto error;
>      }
> @@ -2005,3 +2019,21 @@ error:
>      vout_IntfReinit(vout);
>      return 0;
>  }
> +
> +vlc_decoder_device *vout_GetDevice(const vout_configuration_t *cfg)
> +{
> +    vout_thread_t *vout = cfg->vout;
> +    vout_thread_sys_t *sys = vout->p;
> +
> +    if (VoutEnsureEnabledWindow(cfg) != 0)
> +        return NULL;
> +
> +    vlc_mutex_lock(&sys->window_lock);

VoutEnsureEnabledWindow() and vlc_decoder_device_Create() should be called within the same lock to respect atomicity.

I propose you to move the lock oustide the VoutEnsureEnabledWindow() function.

> +    assert(sys->window_enabled);
> +    if (sys->dec_device == NULL)
> +        sys->dec_device = 
> vlc_decoder_device_Create(sys->display_cfg.window);
> +    vlc_decoder_device *dec_device = sys->dec_device ? 
> vlc_decoder_device_Hold( sys->dec_device ) : NULL;
> +    vlc_mutex_unlock(&sys->window_lock);
> +
> +    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
>   */
> -- 
> 2.17.1
> 
> _______________________________________________
> vlc-devel mailing list
> To unsubscribe or modify your subscription options:
> https://mailman.videolan.org/listinfo/vlc-devel