[vlc-devel] [PATCH 03/34] video context: add a function to test if 2 context are similar

[Rémi Denis-Courmont]

Le vendredi 8 novembre 2019, 16:40:07 EET Steve Lhomme a écrit :
> If they are not similar a converter from one to the other should be used.

What is the definition of similar ? For non-serial objects, the idea seems 
rather fishy.

> A NULL callback is allowed, in which case only the type of the video context
> is checked.
> ---
>  include/vlc_picture.h            | 11 +++++++++++
>  modules/hw/vdpau/avcodec.c       |  2 +-
>  modules/video_chroma/d3d11_fmt.c |  2 +-
>  modules/video_chroma/d3d9_fmt.c  |  2 +-
>  src/input/decoder_helpers.c      | 16 ++++++++++++++++
>  src/libvlccore.sym               |  1 +
>  6 files changed, 31 insertions(+), 3 deletions(-)
> 
> diff --git a/include/vlc_picture.h b/include/vlc_picture.h
> index a5931ef67af..c9bf28a9ed8 100644
> --- a/include/vlc_picture.h
> +++ b/include/vlc_picture.h
> @@ -85,6 +85,11 @@ typedef struct vlc_video_context vlc_video_context;
>  struct vlc_video_context_operations
>  {
>      void (*destroy)(void *priv);
> +    /**
> +     * Check if two video context of the same type are similar.
> +     * The callback can be NULL.
> +     */
> +    bool (*similar)(const vlc_video_context*, const vlc_video_context*);
>  };
> 
>  /** Decoder device type */
> @@ -110,6 +115,12 @@ VLC_API void
> vlc_video_context_Release(vlc_video_context *); VLC_API enum
> vlc_video_context_type vlc_video_context_GetType(const vlc_video_context
> *); VLC_API void *vlc_video_context_GetPrivate(vlc_video_context *, enum
> vlc_video_context_type); VLC_API vlc_video_context
> *vlc_video_context_Hold(vlc_video_context *); +/**
> + * Test if two video context are similar/compatible.
> + *
> + * Video Context are similar when they can use surfaces from one another.
> + */
> +VLC_API bool vlc_video_context_IsSimilar(const vlc_video_context *, const
> vlc_video_context *);
> 
>  /**
>   * Get the decoder device used by the device context.
> diff --git a/modules/hw/vdpau/avcodec.c b/modules/hw/vdpau/avcodec.c
> index 74aa135f70c..6f9a75fd803 100644
> --- a/modules/hw/vdpau/avcodec.c
> +++ b/modules/hw/vdpau/avcodec.c
> @@ -153,7 +153,7 @@ static void DestroyVDPAUVideoContext(void *private)
>  }
> 
>  const struct vlc_video_context_operations vdpau_vctx_ops = {
> -    DestroyVDPAUVideoContext,
> +    DestroyVDPAUVideoContext, NULL // TODO
>  };
> 
>  static int Open(vlc_va_t *va, AVCodecContext *avctx, const
> AVPixFmtDescriptor *desc, diff --git a/modules/video_chroma/d3d11_fmt.c
> b/modules/video_chroma/d3d11_fmt.c index 77156f509bb..edb39244a33 100644
> --- a/modules/video_chroma/d3d11_fmt.c
> +++ b/modules/video_chroma/d3d11_fmt.c
> @@ -771,7 +771,7 @@ static void ReleaseD3D11ContextPrivate(void *private)
>  }
> 
>  const struct vlc_video_context_operations d3d11_vctx_ops = {
> -    ReleaseD3D11ContextPrivate,
> +    ReleaseD3D11ContextPrivate, NULL // TODO
>  };
> 
>  void d3d11_pic_context_destroy(picture_context_t *ctx)
> diff --git a/modules/video_chroma/d3d9_fmt.c
> b/modules/video_chroma/d3d9_fmt.c index 508bfc838f8..3a53484908e 100644
> --- a/modules/video_chroma/d3d9_fmt.c
> +++ b/modules/video_chroma/d3d9_fmt.c
> @@ -293,7 +293,7 @@ static void ReleaseD3D9ContextPrivate(void *private)
>  }
> 
>  const struct vlc_video_context_operations d3d9_vctx_ops = {
> -    ReleaseD3D9ContextPrivate,
> +    ReleaseD3D9ContextPrivate, NULL // TODO
>  };
> 
>  void d3d9_pic_context_destroy(picture_context_t *ctx)
> diff --git a/src/input/decoder_helpers.c b/src/input/decoder_helpers.c
> index 3ff71f49c23..e4b8f2797b6 100644
> --- a/src/input/decoder_helpers.c
> +++ b/src/input/decoder_helpers.c
> @@ -294,3 +294,19 @@ vlc_decoder_device*
> vlc_video_context_HoldDevice(vlc_video_context *vctx) return NULL;
>      return vlc_decoder_device_Hold( vctx->device );
>  }
> +
> +bool vlc_video_context_IsSimilar(const vlc_video_context *a, const
> vlc_video_context *b) +{
> +    if (!a && !b)
> +        return true;
> +    if (!a || !b)
> +        return false;

if (a == NULL || b == NULL)
    return a == b;

> +    if (a->private_type != b->private_type)
> +        return false;
> +    if (a->ops == NULL)
> +    {
> +        assert(b->ops == NULL);
> +        return b->ops == NULL;
> +    }
> +    return a->ops->similar == NULL || a->ops->similar(a, b);
> +}
> diff --git a/src/libvlccore.sym b/src/libvlccore.sym
> index 7dce1c2c25b..3ea59614722 100644
> --- a/src/libvlccore.sym
> +++ b/src/libvlccore.sym
> @@ -952,3 +952,4 @@ vlc_video_context_GetType
>  vlc_video_context_GetPrivate
>  vlc_video_context_Hold
>  vlc_video_context_HoldDevice
> +vlc_video_context_IsSimilar


-- 
Rémi Denis-Courmont