[FFmpeg-devel] [PATCH] Vulkan hwcontext and filters

Mark Thompson sw at jkqxz.net
Sat Jan 18 22:33:06 EET 2020


On 10/01/2020 21:05, Lynne wrote:
> From e2d18e03e3a5fa8ef82159c68212b720198a9b91 Mon Sep 17 00:00:00 2001
> From: Philip Langdale <philipl at overt.org>
> Date: Wed, 23 Oct 2019 18:11:37 -0700
> Subject: [PATCH 3/9] lavfi/vf_hwupload: Add support for HW -> HW transfers
> 
> As we find ourselves wanting a way to transfer frames between
> HW devices (or more realistically, between APIs on the same device),
> it's desirable to have a way to describe the relationship. While
> we could imagine introducing a `hwtransfer` filter, there is
> almost no difference from `hwupload`. The main new feature we need
> is a way to specify the target device. Having a single device
> for the filter chain is obviously insufficient if we're dealing
> with two devices.
> 
> So let's add a way to specify the upload target device, and if none
> is specified, continue with the existing behaviour.
> 
> We must also correctly preserve the sw_format on such a transfer.
> ---
>  doc/filters.texi               | 13 ++++++++-
>  libavfilter/vf_hwupload.c      | 51 +++++++++++++++++++++++++---------
>  libavfilter/vf_hwupload_cuda.c | 10 ++++++-
>  3 files changed, 59 insertions(+), 15 deletions(-)
> 
> diff --git a/doc/filters.texi b/doc/filters.texi
> index 6fb660b05a..d0a564c8e7 100644
> --- a/doc/filters.texi
> +++ b/doc/filters.texi
> @@ -11938,7 +11938,18 @@ Upload system memory frames to hardware surfaces.
>  
>  The device to upload to must be supplied when the filter is initialised.  If
>  using ffmpeg, select the appropriate device with the @option{-filter_hw_device}
> -option.
> +option or with the @option{derive_device} option.  The input and output devices
> +must be of different types and compatible - the exact meaning of this is
> +system-dependent, but typically it means that they must refer to the same
> +underlying hardware context (for example, refer to the same graphics card).
> +
> +The following additional parameters are accepted:
> +
> + at table @option
> + at item derive_device @var{type}
> +Rather than using the device supplied at initialisation, instead derive a new
> +device of type @var{type} from the device the input frames exist on.
> + at end table

Maybe make it a bit clearer that this can only apply to device-to-device transfers?

>  
>  @anchor{hwupload_cuda}
>  @section hwupload_cuda
> diff --git a/libavfilter/vf_hwupload.c b/libavfilter/vf_hwupload.c
> index 50bc7e10f6..7c5dd497b0 100644
> --- a/libavfilter/vf_hwupload.c
> +++ b/libavfilter/vf_hwupload.c
> @@ -32,10 +32,11 @@ typedef struct HWUploadContext {
>      const AVClass *class;
>  
>      AVBufferRef       *hwdevice_ref;
> -    AVHWDeviceContext *hwdevice;
>  
>      AVBufferRef       *hwframes_ref;
>      AVHWFramesContext *hwframes;
> +
> +    char *device_type;
>  } HWUploadContext;
>  
>  static int hwupload_query_formats(AVFilterContext *avctx)
> @@ -46,17 +47,27 @@ static int hwupload_query_formats(AVFilterContext *avctx)
>      AVFilterFormats *input_formats = NULL;
>      int err, i;
>  
> -    if (!avctx->hw_device_ctx) {
> +    if (ctx->hwdevice_ref) {
> +        /* We already have a specified device. */
> +    } else if (avctx->hw_device_ctx) {
> +        if (ctx->device_type) {
> +            err = av_hwdevice_ctx_create_derived(
> +                &ctx->hwdevice_ref,
> +                av_hwdevice_find_type_by_name(ctx->device_type),
> +                avctx->hw_device_ctx, 0);
> +            if (err < 0)

Add an error message here to say that the derivation went wrong so the user knows what to check.

> +                return err;
> +        } else {
> +            ctx->hwdevice_ref = av_buffer_ref(avctx->hw_device_ctx);
> +            if (!ctx->hwdevice_ref)
> +                return AVERROR(ENOMEM);
> +        }
> +    } else {
>          av_log(ctx, AV_LOG_ERROR, "A hardware device reference is required "
>                 "to upload frames to.\n");
>          return AVERROR(EINVAL);
>      }
>  
> -    ctx->hwdevice_ref = av_buffer_ref(avctx->hw_device_ctx);
> -    if (!ctx->hwdevice_ref)
> -        return AVERROR(ENOMEM);
> -    ctx->hwdevice = (AVHWDeviceContext*)ctx->hwdevice_ref->data;
> -
>      constraints = av_hwdevice_get_hwframe_constraints(ctx->hwdevice_ref, NULL);
>      if (!constraints) {
>          err = AVERROR(EINVAL);
> @@ -127,7 +138,13 @@ static int hwupload_config_output(AVFilterLink *outlink)
>             av_get_pix_fmt_name(inlink->format));
>  
>      ctx->hwframes->format    = outlink->format;
> -    ctx->hwframes->sw_format = inlink->format;
> +    if (inlink->hw_frames_ctx) {
> +        AVHWFramesContext *in_hwframe_ctx =
> +            (AVHWFramesContext*)inlink->hw_frames_ctx->data;
> +        ctx->hwframes->sw_format = in_hwframe_ctx->sw_format;
> +    } else {
> +        ctx->hwframes->sw_format = inlink->format;
> +    }
>      ctx->hwframes->width     = inlink->w;
>      ctx->hwframes->height    = inlink->h;
>  
> @@ -200,13 +217,21 @@ static av_cold void hwupload_uninit(AVFilterContext *avctx)
>      av_buffer_unref(&ctx->hwdevice_ref);
>  }
>  
> -static const AVClass hwupload_class = {
> -    .class_name = "hwupload",
> -    .item_name  = av_default_item_name,
> -    .option     = NULL,
> -    .version    = LIBAVUTIL_VERSION_INT,
> +#define OFFSET(x) offsetof(HWUploadContext, x)
> +#define FLAGS (AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM)
> +static const AVOption hwupload_options[] = {
> +    {
> +        "derive_device", "Derive a new device of this type",
> +        OFFSET(device_type), AV_OPT_TYPE_STRING,
> +        { .str = NULL }, 0, 0, FLAGS
> +    },
> +    {
> +        NULL
> +    }
>  };
>  
> +AVFILTER_DEFINE_CLASS(hwupload);
> +
>  static const AVFilterPad hwupload_inputs[] = {
>      {
>          .name         = "default",
> diff --git a/libavfilter/vf_hwupload_cuda.c b/libavfilter/vf_hwupload_cuda.c
> index 4d83e6c8f2..8ee0825859 100644
> --- a/libavfilter/vf_hwupload_cuda.c
> +++ b/libavfilter/vf_hwupload_cuda.c
> @@ -60,6 +60,9 @@ static int cudaupload_query_formats(AVFilterContext *ctx)
>          AV_PIX_FMT_NV12, AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV444P,
>          AV_PIX_FMT_P010, AV_PIX_FMT_P016, AV_PIX_FMT_YUV444P16,
>          AV_PIX_FMT_0RGB32, AV_PIX_FMT_0BGR32,
> +#if CONFIG_VULKAN
> +        AV_PIX_FMT_VULKAN,
> +#endif

I guess there is no way to make sure this is only exposed on actually-supported devices?

>          AV_PIX_FMT_NONE,
>      };
>      static const enum AVPixelFormat output_pix_fmts[] = {
> @@ -97,7 +100,12 @@ static int cudaupload_config_output(AVFilterLink *outlink)
>  
>      hwframe_ctx            = (AVHWFramesContext*)s->hwframe->data;
>      hwframe_ctx->format    = AV_PIX_FMT_CUDA;
> -    hwframe_ctx->sw_format = inlink->format;
> +    if (inlink->hw_frames_ctx) {
> +        AVHWFramesContext *in_hwframe_ctx = (AVHWFramesContext*)inlink->hw_frames_ctx->data;
> +        hwframe_ctx->sw_format = in_hwframe_ctx->sw_format;
> +    } else {
> +        hwframe_ctx->sw_format = inlink->format;
> +    }
>      hwframe_ctx->width     = inlink->w;
>      hwframe_ctx->height    = inlink->h;
>  
> -- 
> 2.25.0.rc2
> 

Thanks,

- Mark


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