libavfilter/vf_scale_cuda.c - manifest_repos/ffmpeg - Git at Google

 /*
 * Copyright (c) 2017, NVIDIA CORPORATION. All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */

 #include <float.h>
 #include <stdio.h>
 #include <string.h>

 #include "libavutil/avstring.h"
 #include "libavutil/common.h"
 #include "libavutil/hwcontext.h"
 #include "libavutil/hwcontext_cuda_internal.h"
 #include "libavutil/cuda_check.h"
 #include "libavutil/internal.h"
 #include "libavutil/opt.h"
 #include "libavutil/pixdesc.h"

 #include "avfilter.h"
 #include "formats.h"
 #include "internal.h"
 #include "scale_eval.h"
 #include "video.h"

 #include "vf_scale_cuda.h"

 static const enum AVPixelFormat supported_formats[] = {
     AV_PIX_FMT_YUV420P,
     AV_PIX_FMT_NV12,
     AV_PIX_FMT_YUV444P,
     AV_PIX_FMT_P010,
     AV_PIX_FMT_P016,
     AV_PIX_FMT_YUV444P16,
     AV_PIX_FMT_0RGB32,
     AV_PIX_FMT_0BGR32,
 };

 #define DIV_UP(a, b) ( ((a) + (b) - 1) / (b) )
 #define BLOCKX 32
 #define BLOCKY 16

 #define CHECK_CU(x) FF_CUDA_CHECK_DL(ctx, s->hwctx->internal->cuda_dl, x)

 enum {
     INTERP_ALGO_DEFAULT,

     INTERP_ALGO_NEAREST,
     INTERP_ALGO_BILINEAR,
     INTERP_ALGO_BICUBIC,
     INTERP_ALGO_LANCZOS,

     INTERP_ALGO_COUNT
 };

 typedef struct CUDAScaleContext {
     const AVClass *class;

     AVCUDADeviceContext *hwctx;

     enum AVPixelFormat in_fmt;
     enum AVPixelFormat out_fmt;

     AVBufferRef *frames_ctx;
     AVFrame     *frame;

     AVFrame *tmp_frame;
     int passthrough;

     /**
      * Output sw format. AV_PIX_FMT_NONE for no conversion.
      */
     enum AVPixelFormat format;

     char *w_expr;               ///< width  expression string
     char *h_expr;               ///< height expression string

     int force_original_aspect_ratio;
     int force_divisible_by;

     CUcontext   cu_ctx;
     CUmodule    cu_module;
     CUfunction  cu_func_uchar;
     CUfunction  cu_func_uchar2;
     CUfunction  cu_func_uchar4;
     CUfunction  cu_func_ushort;
     CUfunction  cu_func_ushort2;
     CUfunction  cu_func_ushort4;
     CUstream    cu_stream;

     CUdeviceptr srcBuffer;
     CUdeviceptr dstBuffer;
     int         tex_alignment;

     int interp_algo;
     int interp_use_linear;
     int interp_as_integer;

     float param;
 } CUDAScaleContext;

 static av_cold int cudascale_init(AVFilterContext *ctx)
 {
     CUDAScaleContext *s = ctx->priv;

     s->format = AV_PIX_FMT_NONE;
     s->frame = av_frame_alloc();
     if (!s->frame)
         return AVERROR(ENOMEM);

     s->tmp_frame = av_frame_alloc();
     if (!s->tmp_frame)
         return AVERROR(ENOMEM);

     return 0;
 }

 static av_cold void cudascale_uninit(AVFilterContext *ctx)
 {
     CUDAScaleContext *s = ctx->priv;

     if (s->hwctx && s->cu_module) {
         CudaFunctions *cu = s->hwctx->internal->cuda_dl;
         CUcontext dummy;

         CHECK_CU(cu->cuCtxPushCurrent(s->hwctx->cuda_ctx));
         CHECK_CU(cu->cuModuleUnload(s->cu_module));
         s->cu_module = NULL;
         CHECK_CU(cu->cuCtxPopCurrent(&dummy));
     }

     av_frame_free(&s->frame);
     av_buffer_unref(&s->frames_ctx);
     av_frame_free(&s->tmp_frame);
 }

 static int cudascale_query_formats(AVFilterContext *ctx)
 {
     static const enum AVPixelFormat pixel_formats[] = {
         AV_PIX_FMT_CUDA, AV_PIX_FMT_NONE,
     };
     AVFilterFormats *pix_fmts = ff_make_format_list(pixel_formats);
     if (!pix_fmts)
         return AVERROR(ENOMEM);

     return ff_set_common_formats(ctx, pix_fmts);
 }

 static av_cold int init_hwframe_ctx(CUDAScaleContext *s, AVBufferRef *device_ctx, int width, int height)
 {
     AVBufferRef *out_ref = NULL;
     AVHWFramesContext *out_ctx;
     int ret;

     out_ref = av_hwframe_ctx_alloc(device_ctx);
     if (!out_ref)
         return AVERROR(ENOMEM);
     out_ctx = (AVHWFramesContext*)out_ref->data;

     out_ctx->format    = AV_PIX_FMT_CUDA;
     out_ctx->sw_format = s->out_fmt;
     out_ctx->width     = FFALIGN(width,  32);
     out_ctx->height    = FFALIGN(height, 32);

     ret = av_hwframe_ctx_init(out_ref);
     if (ret < 0)
         goto fail;

     av_frame_unref(s->frame);
     ret = av_hwframe_get_buffer(out_ref, s->frame, 0);
     if (ret < 0)
         goto fail;

     s->frame->width  = width;
     s->frame->height = height;

     av_buffer_unref(&s->frames_ctx);
     s->frames_ctx = out_ref;

     return 0;
 fail:
     av_buffer_unref(&out_ref);
     return ret;
 }

 static int format_is_supported(enum AVPixelFormat fmt)
 {
     int i;

     for (i = 0; i < FF_ARRAY_ELEMS(supported_formats); i++)
         if (supported_formats[i] == fmt)
             return 1;
     return 0;
 }

 static av_cold int init_processing_chain(AVFilterContext *ctx, int in_width, int in_height,
                                          int out_width, int out_height)
 {
     CUDAScaleContext *s = ctx->priv;

     AVHWFramesContext *in_frames_ctx;

     enum AVPixelFormat in_format;
     enum AVPixelFormat out_format;
     int ret;

     /* check that we have a hw context */
     if (!ctx->inputs[0]->hw_frames_ctx) {
         av_log(ctx, AV_LOG_ERROR, "No hw context provided on input\n");
         return AVERROR(EINVAL);
     }
     in_frames_ctx = (AVHWFramesContext*)ctx->inputs[0]->hw_frames_ctx->data;
     in_format     = in_frames_ctx->sw_format;
     out_format    = (s->format == AV_PIX_FMT_NONE) ? in_format : s->format;

     if (!format_is_supported(in_format)) {
         av_log(ctx, AV_LOG_ERROR, "Unsupported input format: %s\n",
                av_get_pix_fmt_name(in_format));
         return AVERROR(ENOSYS);
     }
     if (!format_is_supported(out_format)) {
         av_log(ctx, AV_LOG_ERROR, "Unsupported output format: %s\n",
                av_get_pix_fmt_name(out_format));
         return AVERROR(ENOSYS);
     }

     s->in_fmt = in_format;
     s->out_fmt = out_format;

     if (s->passthrough && in_width == out_width && in_height == out_height && in_format == out_format) {
         s->frames_ctx = av_buffer_ref(ctx->inputs[0]->hw_frames_ctx);
         if (!s->frames_ctx)
             return AVERROR(ENOMEM);
     } else {
         s->passthrough = 0;

         ret = init_hwframe_ctx(s, in_frames_ctx->device_ref, out_width, out_height);
         if (ret < 0)
             return ret;
     }

     ctx->outputs[0]->hw_frames_ctx = av_buffer_ref(s->frames_ctx);
     if (!ctx->outputs[0]->hw_frames_ctx)
         return AVERROR(ENOMEM);

     return 0;
 }

 static av_cold int cudascale_config_props(AVFilterLink *outlink)
 {
     AVFilterContext *ctx = outlink->src;
     AVFilterLink *inlink = outlink->src->inputs[0];
     CUDAScaleContext *s  = ctx->priv;
     AVHWFramesContext     *frames_ctx = (AVHWFramesContext*)inlink->hw_frames_ctx->data;
     AVCUDADeviceContext *device_hwctx = frames_ctx->device_ctx->hwctx;
     CUcontext dummy, cuda_ctx = device_hwctx->cuda_ctx;
     CudaFunctions *cu = device_hwctx->internal->cuda_dl;
     char buf[64];
     int w, h;
     int ret;

     char *scaler_ptx;
     const char *function_infix = "";

     extern char vf_scale_cuda_ptx[];
     extern char vf_scale_cuda_bicubic_ptx[];

     switch(s->interp_algo) {
     case INTERP_ALGO_NEAREST:
         scaler_ptx = vf_scale_cuda_ptx;
         function_infix = "_Nearest";
         s->interp_use_linear = 0;
         s->interp_as_integer = 1;
         break;
     case INTERP_ALGO_BILINEAR:
         scaler_ptx = vf_scale_cuda_ptx;
         function_infix = "_Bilinear";
         s->interp_use_linear = 1;
         s->interp_as_integer = 1;
         break;
     case INTERP_ALGO_DEFAULT:
     case INTERP_ALGO_BICUBIC:
         scaler_ptx = vf_scale_cuda_bicubic_ptx;
         function_infix = "_Bicubic";
         s->interp_use_linear = 0;
         s->interp_as_integer = 0;
         break;
     case INTERP_ALGO_LANCZOS:
         scaler_ptx = vf_scale_cuda_bicubic_ptx;
         function_infix = "_Lanczos";
         s->interp_use_linear = 0;
         s->interp_as_integer = 0;
         break;
     default:
         av_log(ctx, AV_LOG_ERROR, "Unknown interpolation algorithm\n");
         return AVERROR_BUG;
     }

     s->hwctx = device_hwctx;
     s->cu_stream = s->hwctx->stream;

     ret = CHECK_CU(cu->cuCtxPushCurrent(cuda_ctx));
     if (ret < 0)
         goto fail;

     ret = CHECK_CU(cu->cuModuleLoadData(&s->cu_module, scaler_ptx));
     if (ret < 0)
         goto fail;

     snprintf(buf, sizeof(buf), "Subsample%s_uchar", function_infix);
     CHECK_CU(cu->cuModuleGetFunction(&s->cu_func_uchar, s->cu_module, buf));
     if (ret < 0)
         goto fail;

     snprintf(buf, sizeof(buf), "Subsample%s_uchar2", function_infix);
     CHECK_CU(cu->cuModuleGetFunction(&s->cu_func_uchar2, s->cu_module, buf));
     if (ret < 0)
         goto fail;

     snprintf(buf, sizeof(buf), "Subsample%s_uchar4", function_infix);
     CHECK_CU(cu->cuModuleGetFunction(&s->cu_func_uchar4, s->cu_module, buf));
     if (ret < 0)
         goto fail;

     snprintf(buf, sizeof(buf), "Subsample%s_ushort", function_infix);
     CHECK_CU(cu->cuModuleGetFunction(&s->cu_func_ushort, s->cu_module, buf));
     if (ret < 0)
         goto fail;

     snprintf(buf, sizeof(buf), "Subsample%s_ushort2", function_infix);
     CHECK_CU(cu->cuModuleGetFunction(&s->cu_func_ushort2, s->cu_module, buf));
     if (ret < 0)
         goto fail;

     snprintf(buf, sizeof(buf), "Subsample%s_ushort4", function_infix);
     CHECK_CU(cu->cuModuleGetFunction(&s->cu_func_ushort4, s->cu_module, buf));
     if (ret < 0)
         goto fail;


     CHECK_CU(cu->cuCtxPopCurrent(&dummy));

     if ((ret = ff_scale_eval_dimensions(s,
                                         s->w_expr, s->h_expr,
                                         inlink, outlink,
                                         &w, &h)) < 0)
         goto fail;

     ff_scale_adjust_dimensions(inlink, &w, &h,
                                s->force_original_aspect_ratio, s->force_divisible_by);

     if (((int64_t)h * inlink->w) > INT_MAX  ||
         ((int64_t)w * inlink->h) > INT_MAX)
         av_log(ctx, AV_LOG_ERROR, "Rescaled value for width or height is too big.\n");

     outlink->w = w;
     outlink->h = h;

     ret = init_processing_chain(ctx, inlink->w, inlink->h, w, h);
     if (ret < 0)
         return ret;

     av_log(ctx, AV_LOG_VERBOSE, "w:%d h:%d -> w:%d h:%d%s\n",
            inlink->w, inlink->h, outlink->w, outlink->h, s->passthrough ? " (passthrough)" : "");

     if (inlink->sample_aspect_ratio.num) {
         outlink->sample_aspect_ratio = av_mul_q((AVRational){outlink->h*inlink->w,
                                                              outlink->w*inlink->h},
                                                 inlink->sample_aspect_ratio);
     } else {
         outlink->sample_aspect_ratio = inlink->sample_aspect_ratio;
     }

     return 0;

 fail:
     return ret;
 }

 static int call_resize_kernel(AVFilterContext *ctx, CUfunction func, int channels,
                               uint8_t *src_dptr, int src_width, int src_height, int src_pitch,
                               uint8_t *dst_dptr, int dst_width, int dst_height, int dst_pitch,
                               int pixel_size, int bit_depth)
 {
     CUDAScaleContext *s = ctx->priv;
     CudaFunctions *cu = s->hwctx->internal->cuda_dl;
     CUdeviceptr dst_devptr = (CUdeviceptr)dst_dptr;
     CUtexObject tex = 0;
     void *args_uchar[] = { &tex, &dst_devptr, &dst_width, &dst_height, &dst_pitch,
                            &src_width, &src_height, &bit_depth, &s->param };
     int ret;

     CUDA_TEXTURE_DESC tex_desc = {
         .filterMode = s->interp_use_linear ?
                       CU_TR_FILTER_MODE_LINEAR :
                       CU_TR_FILTER_MODE_POINT,
         .flags = s->interp_as_integer ? CU_TRSF_READ_AS_INTEGER : 0,
     };

     CUDA_RESOURCE_DESC res_desc = {
         .resType = CU_RESOURCE_TYPE_PITCH2D,
         .res.pitch2D.format = pixel_size == 1 ?
                               CU_AD_FORMAT_UNSIGNED_INT8 :
                               CU_AD_FORMAT_UNSIGNED_INT16,
         .res.pitch2D.numChannels = channels,
         .res.pitch2D.width = src_width,
         .res.pitch2D.height = src_height,
         .res.pitch2D.pitchInBytes = src_pitch,
         .res.pitch2D.devPtr = (CUdeviceptr)src_dptr,
     };

     // Handling of channels is done via vector-types in cuda, so their size is implicitly part of the pitch
     // Same for pixel_size, which is represented via datatypes on the cuda side of things.
     dst_pitch /= channels * pixel_size;

     ret = CHECK_CU(cu->cuTexObjectCreate(&tex, &res_desc, &tex_desc, NULL));
     if (ret < 0)
         goto exit;

     ret = CHECK_CU(cu->cuLaunchKernel(func,
                                       DIV_UP(dst_width, BLOCKX), DIV_UP(dst_height, BLOCKY), 1,
                                       BLOCKX, BLOCKY, 1, 0, s->cu_stream, args_uchar, NULL));

 exit:
     if (tex)
         CHECK_CU(cu->cuTexObjectDestroy(tex));

     return ret;
 }

 static int scalecuda_resize(AVFilterContext *ctx,
                             AVFrame *out, AVFrame *in)
 {
     AVHWFramesContext *in_frames_ctx = (AVHWFramesContext*)in->hw_frames_ctx->data;
     CUDAScaleContext *s = ctx->priv;

     switch (in_frames_ctx->sw_format) {
     case AV_PIX_FMT_YUV420P:
         call_resize_kernel(ctx, s->cu_func_uchar, 1,
                            in->data[0], in->width, in->height, in->linesize[0],
                            out->data[0], out->width, out->height, out->linesize[0],
                            1, 8);
         call_resize_kernel(ctx, s->cu_func_uchar, 1,
                            in->data[1], in->width / 2, in->height / 2, in->linesize[1],
                            out->data[1], out->width / 2, out->height / 2, out->linesize[1],
                            1, 8);
         call_resize_kernel(ctx, s->cu_func_uchar, 1,
                            in->data[2], in->width / 2, in->height / 2, in->linesize[2],
                            out->data[2], out->width / 2, out->height / 2, out->linesize[2],
                            1, 8);
         break;
     case AV_PIX_FMT_YUV444P:
         call_resize_kernel(ctx, s->cu_func_uchar, 1,
                            in->data[0], in->width, in->height, in->linesize[0],
                            out->data[0], out->width, out->height, out->linesize[0],
                            1, 8);
         call_resize_kernel(ctx, s->cu_func_uchar, 1,
                            in->data[1], in->width, in->height, in->linesize[1],
                            out->data[1], out->width, out->height, out->linesize[1],
                            1, 8);
         call_resize_kernel(ctx, s->cu_func_uchar, 1,
                            in->data[2], in->width, in->height, in->linesize[2],
                            out->data[2], out->width, out->height, out->linesize[2],
                            1, 8);
         break;
     case AV_PIX_FMT_YUV444P16:
         call_resize_kernel(ctx, s->cu_func_ushort, 1,
                            in->data[0], in->width, in->height, in->linesize[0],
                            out->data[0], out->width, out->height, out->linesize[0],
                            2, 16);
         call_resize_kernel(ctx, s->cu_func_ushort, 1,
                            in->data[1], in->width, in->height, in->linesize[1],
                            out->data[1], out->width, out->height, out->linesize[1],
                            2, 16);
         call_resize_kernel(ctx, s->cu_func_ushort, 1,
                            in->data[2], in->width, in->height, in->linesize[2],
                            out->data[2], out->width, out->height, out->linesize[2],
                            2, 16);
         break;
     case AV_PIX_FMT_NV12:
         call_resize_kernel(ctx, s->cu_func_uchar, 1,
                            in->data[0], in->width, in->height, in->linesize[0],
                            out->data[0], out->width, out->height, out->linesize[0],
                            1, 8);
         call_resize_kernel(ctx, s->cu_func_uchar2, 2,
                            in->data[1], in->width / 2, in->height / 2, in->linesize[1],
                            out->data[1], out->width / 2, out->height / 2, out->linesize[1],
                            1, 8);
         break;
     case AV_PIX_FMT_P010LE:
         call_resize_kernel(ctx, s->cu_func_ushort, 1,
                            in->data[0], in->width, in->height, in->linesize[0],
                            out->data[0], out->width, out->height, out->linesize[0],
                            2, 10);
         call_resize_kernel(ctx, s->cu_func_ushort2, 2,
                            in->data[1], in->width / 2, in->height / 2, in->linesize[1],
                            out->data[1], out->width / 2, out->height / 2, out->linesize[1],
                            2, 10);
         break;
     case AV_PIX_FMT_P016LE:
         call_resize_kernel(ctx, s->cu_func_ushort, 1,
                            in->data[0], in->width, in->height, in->linesize[0],
                            out->data[0], out->width, out->height, out->linesize[0],
                            2, 16);
         call_resize_kernel(ctx, s->cu_func_ushort2, 2,
                            in->data[1], in->width / 2, in->height / 2, in->linesize[1],
                            out->data[1], out->width / 2, out->height / 2, out->linesize[1],
                            2, 16);
         break;
     case AV_PIX_FMT_0RGB32:
     case AV_PIX_FMT_0BGR32:
         call_resize_kernel(ctx, s->cu_func_uchar4, 4,
                            in->data[0], in->width, in->height, in->linesize[0],
                            out->data[0], out->width, out->height, out->linesize[0],
                            1, 8);
         break;
     default:
         return AVERROR_BUG;
     }

     return 0;
 }

 static int cudascale_scale(AVFilterContext *ctx, AVFrame *out, AVFrame *in)
 {
     CUDAScaleContext *s = ctx->priv;
     AVFilterLink *outlink = ctx->outputs[0];
     AVFrame *src = in;
     int ret;

     ret = scalecuda_resize(ctx, s->frame, src);
     if (ret < 0)
         return ret;

     src = s->frame;
     ret = av_hwframe_get_buffer(src->hw_frames_ctx, s->tmp_frame, 0);
     if (ret < 0)
         return ret;

     av_frame_move_ref(out, s->frame);
     av_frame_move_ref(s->frame, s->tmp_frame);

     s->frame->width  = outlink->w;
     s->frame->height = outlink->h;

     ret = av_frame_copy_props(out, in);
     if (ret < 0)
         return ret;

     return 0;
 }

 static int cudascale_filter_frame(AVFilterLink *link, AVFrame *in)
 {
     AVFilterContext       *ctx = link->dst;
     CUDAScaleContext        *s = ctx->priv;
     AVFilterLink      *outlink = ctx->outputs[0];
     CudaFunctions          *cu = s->hwctx->internal->cuda_dl;

     AVFrame *out = NULL;
     CUcontext dummy;
     int ret = 0;

     if (s->passthrough)
         return ff_filter_frame(outlink, in);

     out = av_frame_alloc();
     if (!out) {
         ret = AVERROR(ENOMEM);
         goto fail;
     }

     ret = CHECK_CU(cu->cuCtxPushCurrent(s->hwctx->cuda_ctx));
     if (ret < 0)
         goto fail;

     ret = cudascale_scale(ctx, out, in);

     CHECK_CU(cu->cuCtxPopCurrent(&dummy));
     if (ret < 0)
         goto fail;

     av_reduce(&out->sample_aspect_ratio.num, &out->sample_aspect_ratio.den,
               (int64_t)in->sample_aspect_ratio.num * outlink->h * link->w,
               (int64_t)in->sample_aspect_ratio.den * outlink->w * link->h,
               INT_MAX);

     av_frame_free(&in);
     return ff_filter_frame(outlink, out);
 fail:
     av_frame_free(&in);
     av_frame_free(&out);
     return ret;
 }

 static AVFrame *cudascale_get_video_buffer(AVFilterLink *inlink, int w, int h)
 {
     CUDAScaleContext *s = inlink->dst->priv;

     return s->passthrough ?
         ff_null_get_video_buffer   (inlink, w, h) :
         ff_default_get_video_buffer(inlink, w, h);
 }

 #define OFFSET(x) offsetof(CUDAScaleContext, x)
 #define FLAGS (AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM)
 static const AVOption options[] = {
     { "w", "Output video width",  OFFSET(w_expr), AV_OPT_TYPE_STRING, { .str = "iw" }, .flags = FLAGS },
     { "h", "Output video height", OFFSET(h_expr), AV_OPT_TYPE_STRING, { .str = "ih" }, .flags = FLAGS },
     { "interp_algo", "Interpolation algorithm used for resizing", OFFSET(interp_algo), AV_OPT_TYPE_INT, { .i64 = INTERP_ALGO_DEFAULT }, 0, INTERP_ALGO_COUNT - 1, FLAGS, "interp_algo" },
         { "nearest",  "nearest neighbour", 0, AV_OPT_TYPE_CONST, { .i64 = INTERP_ALGO_NEAREST }, 0, 0, FLAGS, "interp_algo" },
         { "bilinear", "bilinear", 0, AV_OPT_TYPE_CONST, { .i64 = INTERP_ALGO_BILINEAR }, 0, 0, FLAGS, "interp_algo" },
         { "bicubic",  "bicubic",  0, AV_OPT_TYPE_CONST, { .i64 = INTERP_ALGO_BICUBIC  }, 0, 0, FLAGS, "interp_algo" },
         { "lanczos",  "lanczos",  0, AV_OPT_TYPE_CONST, { .i64 = INTERP_ALGO_LANCZOS  }, 0, 0, FLAGS, "interp_algo" },
     { "passthrough", "Do not process frames at all if parameters match", OFFSET(passthrough), AV_OPT_TYPE_BOOL, { .i64 = 1 }, 0, 1, FLAGS },
     { "param", "Algorithm-Specific parameter", OFFSET(param), AV_OPT_TYPE_FLOAT, { .dbl = SCALE_CUDA_PARAM_DEFAULT }, -FLT_MAX, FLT_MAX, FLAGS },
     { "force_original_aspect_ratio", "decrease or increase w/h if necessary to keep the original AR", OFFSET(force_original_aspect_ratio), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 2, FLAGS, "force_oar" },
         { "disable",  NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 0 }, 0, 0, FLAGS, "force_oar" },
         { "decrease", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 1 }, 0, 0, FLAGS, "force_oar" },
         { "increase", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 2 }, 0, 0, FLAGS, "force_oar" },
     { "force_divisible_by", "enforce that the output resolution is divisible by a defined integer when force_original_aspect_ratio is used", OFFSET(force_divisible_by), AV_OPT_TYPE_INT, { .i64 = 1 }, 1, 256, FLAGS },
     { NULL },
 };

 static const AVClass cudascale_class = {
     .class_name = "cudascale",
     .item_name  = av_default_item_name,
     .option     = options,
     .version    = LIBAVUTIL_VERSION_INT,
 };

 static const AVFilterPad cudascale_inputs[] = {
     {
         .name        = "default",
         .type        = AVMEDIA_TYPE_VIDEO,
         .filter_frame = cudascale_filter_frame,
         .get_video_buffer = cudascale_get_video_buffer,
     },
     { NULL }
 };

 static const AVFilterPad cudascale_outputs[] = {
     {
         .name         = "default",
         .type         = AVMEDIA_TYPE_VIDEO,
         .config_props = cudascale_config_props,
     },
     { NULL }
 };

 AVFilter ff_vf_scale_cuda = {
     .name      = "scale_cuda",
     .description = NULL_IF_CONFIG_SMALL("GPU accelerated video resizer"),

     .init          = cudascale_init,
     .uninit        = cudascale_uninit,
     .query_formats = cudascale_query_formats,

     .priv_size = sizeof(CUDAScaleContext),
     .priv_class = &cudascale_class,

     .inputs    = cudascale_inputs,
     .outputs   = cudascale_outputs,

     .flags_internal = FF_FILTER_FLAG_HWFRAME_AWARE,
 };
	/*
	* Copyright (c) 2017, NVIDIA CORPORATION. All rights reserved.
	*
	* Permission is hereby granted, free of charge, to any person obtaining a
	* copy of this software and associated documentation files (the "Software"),
	* to deal in the Software without restriction, including without limitation
	* the rights to use, copy, modify, merge, publish, distribute, sublicense,
	* and/or sell copies of the Software, and to permit persons to whom the
	* Software is furnished to do so, subject to the following conditions:
	*
	* The above copyright notice and this permission notice shall be included in
	* all copies or substantial portions of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
	* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
	* DEALINGS IN THE SOFTWARE.
	*/

	#include <float.h>
	#include <stdio.h>
	#include <string.h>

	#include "libavutil/avstring.h"
	#include "libavutil/common.h"
	#include "libavutil/hwcontext.h"
	#include "libavutil/hwcontext_cuda_internal.h"
	#include "libavutil/cuda_check.h"
	#include "libavutil/internal.h"
	#include "libavutil/opt.h"
	#include "libavutil/pixdesc.h"

	#include "avfilter.h"
	#include "formats.h"
	#include "internal.h"
	#include "scale_eval.h"
	#include "video.h"

	#include "vf_scale_cuda.h"

	static const enum AVPixelFormat supported_formats[] = {
	AV_PIX_FMT_YUV420P,
	AV_PIX_FMT_NV12,
	AV_PIX_FMT_YUV444P,
	AV_PIX_FMT_P010,
	AV_PIX_FMT_P016,
	AV_PIX_FMT_YUV444P16,
	AV_PIX_FMT_0RGB32,
	AV_PIX_FMT_0BGR32,
	};

	#define DIV_UP(a, b) ( ((a) + (b) - 1) / (b) )
	#define BLOCKX 32
	#define BLOCKY 16

	#define CHECK_CU(x) FF_CUDA_CHECK_DL(ctx, s->hwctx->internal->cuda_dl, x)

	enum {
	INTERP_ALGO_DEFAULT,

	INTERP_ALGO_NEAREST,
	INTERP_ALGO_BILINEAR,
	INTERP_ALGO_BICUBIC,
	INTERP_ALGO_LANCZOS,

	INTERP_ALGO_COUNT
	};

	typedef struct CUDAScaleContext {
	const AVClass *class;

	AVCUDADeviceContext *hwctx;

	enum AVPixelFormat in_fmt;
	enum AVPixelFormat out_fmt;

	AVBufferRef *frames_ctx;
	AVFrame *frame;

	AVFrame *tmp_frame;
	int passthrough;

	/**
	* Output sw format. AV_PIX_FMT_NONE for no conversion.
	*/
	enum AVPixelFormat format;

	char *w_expr; ///< width expression string
	char *h_expr; ///< height expression string

	int force_original_aspect_ratio;
	int force_divisible_by;

	CUcontext cu_ctx;
	CUmodule cu_module;
	CUfunction cu_func_uchar;
	CUfunction cu_func_uchar2;
	CUfunction cu_func_uchar4;
	CUfunction cu_func_ushort;
	CUfunction cu_func_ushort2;
	CUfunction cu_func_ushort4;
	CUstream cu_stream;

	CUdeviceptr srcBuffer;
	CUdeviceptr dstBuffer;
	int tex_alignment;

	int interp_algo;
	int interp_use_linear;
	int interp_as_integer;

	float param;
	} CUDAScaleContext;

	static av_cold int cudascale_init(AVFilterContext *ctx)
	{
	CUDAScaleContext *s = ctx->priv;

	s->format = AV_PIX_FMT_NONE;
	s->frame = av_frame_alloc();
	if (!s->frame)
	return AVERROR(ENOMEM);

	s->tmp_frame = av_frame_alloc();
	if (!s->tmp_frame)
	return AVERROR(ENOMEM);

	return 0;
	}

	static av_cold void cudascale_uninit(AVFilterContext *ctx)
	{
	CUDAScaleContext *s = ctx->priv;

	if (s->hwctx && s->cu_module) {
	CudaFunctions *cu = s->hwctx->internal->cuda_dl;
	CUcontext dummy;

	CHECK_CU(cu->cuCtxPushCurrent(s->hwctx->cuda_ctx));
	CHECK_CU(cu->cuModuleUnload(s->cu_module));
	s->cu_module = NULL;
	CHECK_CU(cu->cuCtxPopCurrent(&dummy));
	}

	av_frame_free(&s->frame);
	av_buffer_unref(&s->frames_ctx);
	av_frame_free(&s->tmp_frame);
	}

	static int cudascale_query_formats(AVFilterContext *ctx)
	{
	static const enum AVPixelFormat pixel_formats[] = {
	AV_PIX_FMT_CUDA, AV_PIX_FMT_NONE,
	};
	AVFilterFormats *pix_fmts = ff_make_format_list(pixel_formats);
	if (!pix_fmts)
	return AVERROR(ENOMEM);

	return ff_set_common_formats(ctx, pix_fmts);
	}

	static av_cold int init_hwframe_ctx(CUDAScaleContext s, AVBufferRef device_ctx, int width, int height)
	{
	AVBufferRef *out_ref = NULL;
	AVHWFramesContext *out_ctx;
	int ret;

	out_ref = av_hwframe_ctx_alloc(device_ctx);
	if (!out_ref)
	return AVERROR(ENOMEM);
	out_ctx = (AVHWFramesContext*)out_ref->data;

	out_ctx->format = AV_PIX_FMT_CUDA;
	out_ctx->sw_format = s->out_fmt;
	out_ctx->width = FFALIGN(width, 32);
	out_ctx->height = FFALIGN(height, 32);

	ret = av_hwframe_ctx_init(out_ref);
	if (ret < 0)
	goto fail;

	av_frame_unref(s->frame);
	ret = av_hwframe_get_buffer(out_ref, s->frame, 0);
	if (ret < 0)
	goto fail;

	s->frame->width = width;
	s->frame->height = height;

	av_buffer_unref(&s->frames_ctx);
	s->frames_ctx = out_ref;

	return 0;
	fail:
	av_buffer_unref(&out_ref);
	return ret;
	}

	static int format_is_supported(enum AVPixelFormat fmt)
	{
	int i;

	for (i = 0; i < FF_ARRAY_ELEMS(supported_formats); i++)
	if (supported_formats[i] == fmt)
	return 1;
	return 0;
	}

	static av_cold int init_processing_chain(AVFilterContext *ctx, int in_width, int in_height,
	int out_width, int out_height)
	{
	CUDAScaleContext *s = ctx->priv;

	AVHWFramesContext *in_frames_ctx;

	enum AVPixelFormat in_format;
	enum AVPixelFormat out_format;
	int ret;

	/* check that we have a hw context */
	if (!ctx->inputs[0]->hw_frames_ctx) {
	av_log(ctx, AV_LOG_ERROR, "No hw context provided on input\n");
	return AVERROR(EINVAL);
	}
	in_frames_ctx = (AVHWFramesContext*)ctx->inputs[0]->hw_frames_ctx->data;
	in_format = in_frames_ctx->sw_format;
	out_format = (s->format == AV_PIX_FMT_NONE) ? in_format : s->format;

	if (!format_is_supported(in_format)) {
	av_log(ctx, AV_LOG_ERROR, "Unsupported input format: %s\n",
	av_get_pix_fmt_name(in_format));
	return AVERROR(ENOSYS);
	}
	if (!format_is_supported(out_format)) {
	av_log(ctx, AV_LOG_ERROR, "Unsupported output format: %s\n",
	av_get_pix_fmt_name(out_format));
	return AVERROR(ENOSYS);
	}

	s->in_fmt = in_format;
	s->out_fmt = out_format;

	if (s->passthrough && in_width == out_width && in_height == out_height && in_format == out_format) {
	s->frames_ctx = av_buffer_ref(ctx->inputs[0]->hw_frames_ctx);
	if (!s->frames_ctx)
	return AVERROR(ENOMEM);
	} else {
	s->passthrough = 0;

	ret = init_hwframe_ctx(s, in_frames_ctx->device_ref, out_width, out_height);
	if (ret < 0)
	return ret;
	}

	ctx->outputs[0]->hw_frames_ctx = av_buffer_ref(s->frames_ctx);
	if (!ctx->outputs[0]->hw_frames_ctx)
	return AVERROR(ENOMEM);

	return 0;
	}

	static av_cold int cudascale_config_props(AVFilterLink *outlink)
	{
	AVFilterContext *ctx = outlink->src;
	AVFilterLink *inlink = outlink->src->inputs[0];
	CUDAScaleContext *s = ctx->priv;
	AVHWFramesContext frames_ctx = (AVHWFramesContext)inlink->hw_frames_ctx->data;
	AVCUDADeviceContext *device_hwctx = frames_ctx->device_ctx->hwctx;
	CUcontext dummy, cuda_ctx = device_hwctx->cuda_ctx;
	CudaFunctions *cu = device_hwctx->internal->cuda_dl;
	char buf[64];
	int w, h;
	int ret;

	char *scaler_ptx;
	const char *function_infix = "";

	extern char vf_scale_cuda_ptx[];
	extern char vf_scale_cuda_bicubic_ptx[];

	switch(s->interp_algo) {
	case INTERP_ALGO_NEAREST:
	scaler_ptx = vf_scale_cuda_ptx;
	function_infix = "_Nearest";
	s->interp_use_linear = 0;
	s->interp_as_integer = 1;
	break;
	case INTERP_ALGO_BILINEAR:
	scaler_ptx = vf_scale_cuda_ptx;
	function_infix = "_Bilinear";
	s->interp_use_linear = 1;
	s->interp_as_integer = 1;
	break;
	case INTERP_ALGO_DEFAULT:
	case INTERP_ALGO_BICUBIC:
	scaler_ptx = vf_scale_cuda_bicubic_ptx;
	function_infix = "_Bicubic";
	s->interp_use_linear = 0;
	s->interp_as_integer = 0;
	break;
	case INTERP_ALGO_LANCZOS:
	scaler_ptx = vf_scale_cuda_bicubic_ptx;
	function_infix = "_Lanczos";
	s->interp_use_linear = 0;
	s->interp_as_integer = 0;
	break;
	default:
	av_log(ctx, AV_LOG_ERROR, "Unknown interpolation algorithm\n");
	return AVERROR_BUG;
	}

	s->hwctx = device_hwctx;
	s->cu_stream = s->hwctx->stream;

	ret = CHECK_CU(cu->cuCtxPushCurrent(cuda_ctx));
	if (ret < 0)
	goto fail;

	ret = CHECK_CU(cu->cuModuleLoadData(&s->cu_module, scaler_ptx));
	if (ret < 0)
	goto fail;

	snprintf(buf, sizeof(buf), "Subsample%s_uchar", function_infix);
	CHECK_CU(cu->cuModuleGetFunction(&s->cu_func_uchar, s->cu_module, buf));
	if (ret < 0)
	goto fail;

	snprintf(buf, sizeof(buf), "Subsample%s_uchar2", function_infix);
	CHECK_CU(cu->cuModuleGetFunction(&s->cu_func_uchar2, s->cu_module, buf));
	if (ret < 0)
	goto fail;

	snprintf(buf, sizeof(buf), "Subsample%s_uchar4", function_infix);
	CHECK_CU(cu->cuModuleGetFunction(&s->cu_func_uchar4, s->cu_module, buf));
	if (ret < 0)
	goto fail;

	snprintf(buf, sizeof(buf), "Subsample%s_ushort", function_infix);
	CHECK_CU(cu->cuModuleGetFunction(&s->cu_func_ushort, s->cu_module, buf));
	if (ret < 0)
	goto fail;

	snprintf(buf, sizeof(buf), "Subsample%s_ushort2", function_infix);
	CHECK_CU(cu->cuModuleGetFunction(&s->cu_func_ushort2, s->cu_module, buf));
	if (ret < 0)
	goto fail;

	snprintf(buf, sizeof(buf), "Subsample%s_ushort4", function_infix);
	CHECK_CU(cu->cuModuleGetFunction(&s->cu_func_ushort4, s->cu_module, buf));
	if (ret < 0)
	goto fail;


	CHECK_CU(cu->cuCtxPopCurrent(&dummy));

	if ((ret = ff_scale_eval_dimensions(s,
	s->w_expr, s->h_expr,
	inlink, outlink,
	&w, &h)) < 0)
	goto fail;

	ff_scale_adjust_dimensions(inlink, &w, &h,
	s->force_original_aspect_ratio, s->force_divisible_by);

	if (((int64_t)h * inlink->w) > INT_MAX \|\|
	((int64_t)w * inlink->h) > INT_MAX)
	av_log(ctx, AV_LOG_ERROR, "Rescaled value for width or height is too big.\n");

	outlink->w = w;
	outlink->h = h;

	ret = init_processing_chain(ctx, inlink->w, inlink->h, w, h);
	if (ret < 0)
	return ret;

	av_log(ctx, AV_LOG_VERBOSE, "w:%d h:%d -> w:%d h:%d%s\n",
	inlink->w, inlink->h, outlink->w, outlink->h, s->passthrough ? " (passthrough)" : "");

	if (inlink->sample_aspect_ratio.num) {
	outlink->sample_aspect_ratio = av_mul_q((AVRational){outlink->h*inlink->w,
	outlink->w*inlink->h},
	inlink->sample_aspect_ratio);
	} else {
	outlink->sample_aspect_ratio = inlink->sample_aspect_ratio;
	}

	return 0;

	fail:
	return ret;
	}

	static int call_resize_kernel(AVFilterContext *ctx, CUfunction func, int channels,
	uint8_t *src_dptr, int src_width, int src_height, int src_pitch,
	uint8_t *dst_dptr, int dst_width, int dst_height, int dst_pitch,
	int pixel_size, int bit_depth)
	{
	CUDAScaleContext *s = ctx->priv;
	CudaFunctions *cu = s->hwctx->internal->cuda_dl;
	CUdeviceptr dst_devptr = (CUdeviceptr)dst_dptr;
	CUtexObject tex = 0;
	void *args_uchar[] = { &tex, &dst_devptr, &dst_width, &dst_height, &dst_pitch,
	&src_width, &src_height, &bit_depth, &s->param };
	int ret;

	CUDA_TEXTURE_DESC tex_desc = {
	.filterMode = s->interp_use_linear ?
	CU_TR_FILTER_MODE_LINEAR :
	CU_TR_FILTER_MODE_POINT,
	.flags = s->interp_as_integer ? CU_TRSF_READ_AS_INTEGER : 0,
	};

	CUDA_RESOURCE_DESC res_desc = {
	.resType = CU_RESOURCE_TYPE_PITCH2D,
	.res.pitch2D.format = pixel_size == 1 ?
	CU_AD_FORMAT_UNSIGNED_INT8 :
	CU_AD_FORMAT_UNSIGNED_INT16,
	.res.pitch2D.numChannels = channels,
	.res.pitch2D.width = src_width,
	.res.pitch2D.height = src_height,
	.res.pitch2D.pitchInBytes = src_pitch,
	.res.pitch2D.devPtr = (CUdeviceptr)src_dptr,
	};

	// Handling of channels is done via vector-types in cuda, so their size is implicitly part of the pitch
	// Same for pixel_size, which is represented via datatypes on the cuda side of things.
	dst_pitch /= channels * pixel_size;

	ret = CHECK_CU(cu->cuTexObjectCreate(&tex, &res_desc, &tex_desc, NULL));
	if (ret < 0)
	goto exit;

	ret = CHECK_CU(cu->cuLaunchKernel(func,
	DIV_UP(dst_width, BLOCKX), DIV_UP(dst_height, BLOCKY), 1,
	BLOCKX, BLOCKY, 1, 0, s->cu_stream, args_uchar, NULL));

	exit:
	if (tex)
	CHECK_CU(cu->cuTexObjectDestroy(tex));

	return ret;
	}

	static int scalecuda_resize(AVFilterContext *ctx,
	AVFrame out, AVFrame in)
	{
	AVHWFramesContext in_frames_ctx = (AVHWFramesContext)in->hw_frames_ctx->data;
	CUDAScaleContext *s = ctx->priv;

	switch (in_frames_ctx->sw_format) {
	case AV_PIX_FMT_YUV420P:
	call_resize_kernel(ctx, s->cu_func_uchar, 1,
	in->data[0], in->width, in->height, in->linesize[0],
	out->data[0], out->width, out->height, out->linesize[0],
	1, 8);
	call_resize_kernel(ctx, s->cu_func_uchar, 1,
	in->data[1], in->width / 2, in->height / 2, in->linesize[1],
	out->data[1], out->width / 2, out->height / 2, out->linesize[1],
	1, 8);
	call_resize_kernel(ctx, s->cu_func_uchar, 1,
	in->data[2], in->width / 2, in->height / 2, in->linesize[2],
	out->data[2], out->width / 2, out->height / 2, out->linesize[2],
	1, 8);
	break;
	case AV_PIX_FMT_YUV444P:
	call_resize_kernel(ctx, s->cu_func_uchar, 1,
	in->data[0], in->width, in->height, in->linesize[0],
	out->data[0], out->width, out->height, out->linesize[0],
	1, 8);
	call_resize_kernel(ctx, s->cu_func_uchar, 1,
	in->data[1], in->width, in->height, in->linesize[1],
	out->data[1], out->width, out->height, out->linesize[1],
	1, 8);
	call_resize_kernel(ctx, s->cu_func_uchar, 1,
	in->data[2], in->width, in->height, in->linesize[2],
	out->data[2], out->width, out->height, out->linesize[2],
	1, 8);
	break;
	case AV_PIX_FMT_YUV444P16:
	call_resize_kernel(ctx, s->cu_func_ushort, 1,
	in->data[0], in->width, in->height, in->linesize[0],
	out->data[0], out->width, out->height, out->linesize[0],
	2, 16);
	call_resize_kernel(ctx, s->cu_func_ushort, 1,
	in->data[1], in->width, in->height, in->linesize[1],
	out->data[1], out->width, out->height, out->linesize[1],
	2, 16);
	call_resize_kernel(ctx, s->cu_func_ushort, 1,
	in->data[2], in->width, in->height, in->linesize[2],
	out->data[2], out->width, out->height, out->linesize[2],
	2, 16);
	break;
	case AV_PIX_FMT_NV12:
	call_resize_kernel(ctx, s->cu_func_uchar, 1,
	in->data[0], in->width, in->height, in->linesize[0],
	out->data[0], out->width, out->height, out->linesize[0],
	1, 8);
	call_resize_kernel(ctx, s->cu_func_uchar2, 2,
	in->data[1], in->width / 2, in->height / 2, in->linesize[1],
	out->data[1], out->width / 2, out->height / 2, out->linesize[1],
	1, 8);
	break;
	case AV_PIX_FMT_P010LE:
	call_resize_kernel(ctx, s->cu_func_ushort, 1,
	in->data[0], in->width, in->height, in->linesize[0],
	out->data[0], out->width, out->height, out->linesize[0],
	2, 10);
	call_resize_kernel(ctx, s->cu_func_ushort2, 2,
	in->data[1], in->width / 2, in->height / 2, in->linesize[1],
	out->data[1], out->width / 2, out->height / 2, out->linesize[1],
	2, 10);
	break;
	case AV_PIX_FMT_P016LE:
	call_resize_kernel(ctx, s->cu_func_ushort, 1,
	in->data[0], in->width, in->height, in->linesize[0],
	out->data[0], out->width, out->height, out->linesize[0],
	2, 16);
	call_resize_kernel(ctx, s->cu_func_ushort2, 2,
	in->data[1], in->width / 2, in->height / 2, in->linesize[1],
	out->data[1], out->width / 2, out->height / 2, out->linesize[1],
	2, 16);
	break;
	case AV_PIX_FMT_0RGB32:
	case AV_PIX_FMT_0BGR32:
	call_resize_kernel(ctx, s->cu_func_uchar4, 4,
	in->data[0], in->width, in->height, in->linesize[0],
	out->data[0], out->width, out->height, out->linesize[0],
	1, 8);
	break;
	default:
	return AVERROR_BUG;
	}

	return 0;
	}

	static int cudascale_scale(AVFilterContext ctx, AVFrame out, AVFrame *in)
	{
	CUDAScaleContext *s = ctx->priv;
	AVFilterLink *outlink = ctx->outputs[0];
	AVFrame *src = in;
	int ret;

	ret = scalecuda_resize(ctx, s->frame, src);
	if (ret < 0)
	return ret;

	src = s->frame;
	ret = av_hwframe_get_buffer(src->hw_frames_ctx, s->tmp_frame, 0);
	if (ret < 0)
	return ret;

	av_frame_move_ref(out, s->frame);
	av_frame_move_ref(s->frame, s->tmp_frame);

	s->frame->width = outlink->w;
	s->frame->height = outlink->h;

	ret = av_frame_copy_props(out, in);
	if (ret < 0)
	return ret;

	return 0;
	}

	static int cudascale_filter_frame(AVFilterLink link, AVFrame in)
	{
	AVFilterContext *ctx = link->dst;
	CUDAScaleContext *s = ctx->priv;
	AVFilterLink *outlink = ctx->outputs[0];
	CudaFunctions *cu = s->hwctx->internal->cuda_dl;

	AVFrame *out = NULL;
	CUcontext dummy;
	int ret = 0;

	if (s->passthrough)
	return ff_filter_frame(outlink, in);

	out = av_frame_alloc();
	if (!out) {
	ret = AVERROR(ENOMEM);
	goto fail;
	}

	ret = CHECK_CU(cu->cuCtxPushCurrent(s->hwctx->cuda_ctx));
	if (ret < 0)
	goto fail;

	ret = cudascale_scale(ctx, out, in);

	CHECK_CU(cu->cuCtxPopCurrent(&dummy));
	if (ret < 0)
	goto fail;

	av_reduce(&out->sample_aspect_ratio.num, &out->sample_aspect_ratio.den,
	(int64_t)in->sample_aspect_ratio.num * outlink->h * link->w,
	(int64_t)in->sample_aspect_ratio.den * outlink->w * link->h,
	INT_MAX);

	av_frame_free(&in);
	return ff_filter_frame(outlink, out);
	fail:
	av_frame_free(&in);
	av_frame_free(&out);
	return ret;
	}

	static AVFrame cudascale_get_video_buffer(AVFilterLink inlink, int w, int h)
	{
	CUDAScaleContext *s = inlink->dst->priv;

	return s->passthrough ?
	ff_null_get_video_buffer (inlink, w, h) :
	ff_default_get_video_buffer(inlink, w, h);
	}

	#define OFFSET(x) offsetof(CUDAScaleContext, x)
	#define FLAGS (AV_OPT_FLAG_FILTERING_PARAM\|AV_OPT_FLAG_VIDEO_PARAM)
	static const AVOption options[] = {
	{ "w", "Output video width", OFFSET(w_expr), AV_OPT_TYPE_STRING, { .str = "iw" }, .flags = FLAGS },
	{ "h", "Output video height", OFFSET(h_expr), AV_OPT_TYPE_STRING, { .str = "ih" }, .flags = FLAGS },
	{ "interp_algo", "Interpolation algorithm used for resizing", OFFSET(interp_algo), AV_OPT_TYPE_INT, { .i64 = INTERP_ALGO_DEFAULT }, 0, INTERP_ALGO_COUNT - 1, FLAGS, "interp_algo" },
	{ "nearest", "nearest neighbour", 0, AV_OPT_TYPE_CONST, { .i64 = INTERP_ALGO_NEAREST }, 0, 0, FLAGS, "interp_algo" },
	{ "bilinear", "bilinear", 0, AV_OPT_TYPE_CONST, { .i64 = INTERP_ALGO_BILINEAR }, 0, 0, FLAGS, "interp_algo" },
	{ "bicubic", "bicubic", 0, AV_OPT_TYPE_CONST, { .i64 = INTERP_ALGO_BICUBIC }, 0, 0, FLAGS, "interp_algo" },
	{ "lanczos", "lanczos", 0, AV_OPT_TYPE_CONST, { .i64 = INTERP_ALGO_LANCZOS }, 0, 0, FLAGS, "interp_algo" },
	{ "passthrough", "Do not process frames at all if parameters match", OFFSET(passthrough), AV_OPT_TYPE_BOOL, { .i64 = 1 }, 0, 1, FLAGS },
	{ "param", "Algorithm-Specific parameter", OFFSET(param), AV_OPT_TYPE_FLOAT, { .dbl = SCALE_CUDA_PARAM_DEFAULT }, -FLT_MAX, FLT_MAX, FLAGS },
	{ "force_original_aspect_ratio", "decrease or increase w/h if necessary to keep the original AR", OFFSET(force_original_aspect_ratio), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 2, FLAGS, "force_oar" },
	{ "disable", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 0 }, 0, 0, FLAGS, "force_oar" },
	{ "decrease", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 1 }, 0, 0, FLAGS, "force_oar" },
	{ "increase", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 2 }, 0, 0, FLAGS, "force_oar" },
	{ "force_divisible_by", "enforce that the output resolution is divisible by a defined integer when force_original_aspect_ratio is used", OFFSET(force_divisible_by), AV_OPT_TYPE_INT, { .i64 = 1 }, 1, 256, FLAGS },
	{ NULL },
	};

	static const AVClass cudascale_class = {
	.class_name = "cudascale",
	.item_name = av_default_item_name,
	.option = options,
	.version = LIBAVUTIL_VERSION_INT,
	};

	static const AVFilterPad cudascale_inputs[] = {
	{
	.name = "default",
	.type = AVMEDIA_TYPE_VIDEO,
	.filter_frame = cudascale_filter_frame,
	.get_video_buffer = cudascale_get_video_buffer,
	},
	{ NULL }
	};

	static const AVFilterPad cudascale_outputs[] = {
	{
	.name = "default",
	.type = AVMEDIA_TYPE_VIDEO,
	.config_props = cudascale_config_props,
	},
	{ NULL }
	};

	AVFilter ff_vf_scale_cuda = {
	.name = "scale_cuda",
	.description = NULL_IF_CONFIG_SMALL("GPU accelerated video resizer"),

	.init = cudascale_init,
	.uninit = cudascale_uninit,
	.query_formats = cudascale_query_formats,

	.priv_size = sizeof(CUDAScaleContext),
	.priv_class = &cudascale_class,

	.inputs = cudascale_inputs,
	.outputs = cudascale_outputs,

	.flags_internal = FF_FILTER_FLAG_HWFRAME_AWARE,
	};