/*
  * Nvidia CUVID decoder
  * Copyright (c) 2016 Timo Rothenpieler <timo@rothenpieler.org>
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 

 #include "compat/cuda/dynlink_loader.h"
 

 #include "libavutil/buffer.h"
 #include "libavutil/mathematics.h"
 #include "libavutil/hwcontext.h"

 #include "libavutil/hwcontext_cuda_internal.h"

 #include "libavutil/fifo.h"
 #include "libavutil/log.h"

 #include "libavutil/opt.h"

 #include "libavutil/pixdesc.h"

 
 #include "avcodec.h"
 #include "internal.h"
 
 typedef struct CuvidContext
 {

     AVClass *avclass;
 

     CUvideodecoder cudecoder;
     CUvideoparser cuparser;
 

     char *cu_gpu;

     int nb_surfaces;

     int drop_second_field;

     char *crop_expr;
     char *resize_expr;
 
     struct {
         int left;
         int top;
         int right;
         int bottom;
     } crop;
 
     struct {
         int width;
         int height;
     } resize;

     AVBufferRef *hwdevice;
     AVBufferRef *hwframe;
 
     AVBSFContext *bsf;
 
     AVFifoBuffer *frame_queue;
 

     int deint_mode;

     int deint_mode_current;

     int64_t prev_pts;
 

     int internal_error;

     int decoder_flushing;

 
     cudaVideoCodec codec_type;
     cudaVideoChromaFormat chroma_format;

 
     CUVIDPARSERPARAMS cuparseinfo;
     CUVIDEOFORMATEX cuparse_ext;

 
     CudaFunctions *cudl;
     CuvidFunctions *cvdl;

 } CuvidContext;
 

 typedef struct CuvidParsedFrame
 {
     CUVIDPARSERDISPINFO dispinfo;
     int second_field;
     int is_deinterlacing;
 } CuvidParsedFrame;
 

 static int check_cu(AVCodecContext *avctx, CUresult err, const char *func)
 {

     CuvidContext *ctx = avctx->priv_data;

     const char *err_name;
     const char *err_string;
 
     av_log(avctx, AV_LOG_TRACE, "Calling %s\n", func);
 
     if (err == CUDA_SUCCESS)
         return 0;
 

     ctx->cudl->cuGetErrorName(err, &err_name);
     ctx->cudl->cuGetErrorString(err, &err_string);

 
     av_log(avctx, AV_LOG_ERROR, "%s failed", func);
     if (err_name && err_string)
         av_log(avctx, AV_LOG_ERROR, " -> %s: %s", err_name, err_string);
     av_log(avctx, AV_LOG_ERROR, "\n");
 
     return AVERROR_EXTERNAL;
 }
 
 #define CHECK_CU(x) check_cu(avctx, (x), #x)
 
 static int CUDAAPI cuvid_handle_video_sequence(void *opaque, CUVIDEOFORMAT* format)
 {
     AVCodecContext *avctx = opaque;
     CuvidContext *ctx = avctx->priv_data;
     AVHWFramesContext *hwframe_ctx = (AVHWFramesContext*)ctx->hwframe->data;
     CUVIDDECODECREATEINFO cuinfo;

     int surface_fmt;
 

     int old_width = avctx->width;
     int old_height = avctx->height;
 

     enum AVPixelFormat pix_fmts[3] = { AV_PIX_FMT_CUDA,
                                        AV_PIX_FMT_NONE,  // Will be updated below
                                        AV_PIX_FMT_NONE };

     av_log(avctx, AV_LOG_TRACE, "pfnSequenceCallback, progressive_sequence=%d\n", format->progressive_sequence);

     memset(&cuinfo, 0, sizeof(cuinfo));
 

     ctx->internal_error = 0;
 

     avctx->coded_width = cuinfo.ulWidth = format->coded_width;
     avctx->coded_height = cuinfo.ulHeight = format->coded_height;
 
     // apply cropping
     cuinfo.display_area.left = format->display_area.left + ctx->crop.left;
     cuinfo.display_area.top = format->display_area.top + ctx->crop.top;
     cuinfo.display_area.right = format->display_area.right - ctx->crop.right;
     cuinfo.display_area.bottom = format->display_area.bottom - ctx->crop.bottom;
 

     // width and height need to be set before calling ff_get_format

     if (ctx->resize_expr) {
         avctx->width = ctx->resize.width;
         avctx->height = ctx->resize.height;
     } else {
         avctx->width = cuinfo.display_area.right - cuinfo.display_area.left;
         avctx->height = cuinfo.display_area.bottom - cuinfo.display_area.top;
     }
 
     // target width/height need to be multiples of two
     cuinfo.ulTargetWidth = avctx->width = (avctx->width + 1) & ~1;
     cuinfo.ulTargetHeight = avctx->height = (avctx->height + 1) & ~1;
 
     // aspect ratio conversion, 1:1, depends on scaled resolution
     cuinfo.target_rect.left = 0;
     cuinfo.target_rect.top = 0;
     cuinfo.target_rect.right = cuinfo.ulTargetWidth;
     cuinfo.target_rect.bottom = cuinfo.ulTargetHeight;

     switch (format->bit_depth_luma_minus8) {
     case 0: // 8-bit
         pix_fmts[1] = AV_PIX_FMT_NV12;
         break;
     case 2: // 10-bit
         pix_fmts[1] = AV_PIX_FMT_P010;
         break;
     case 4: // 12-bit
         pix_fmts[1] = AV_PIX_FMT_P016;
         break;
     default:
         av_log(avctx, AV_LOG_ERROR, "unsupported bit depth: %d\n",
                format->bit_depth_luma_minus8 + 8);
         ctx->internal_error = AVERROR(EINVAL);
         return 0;
     }
     surface_fmt = ff_get_format(avctx, pix_fmts);
     if (surface_fmt < 0) {
         av_log(avctx, AV_LOG_ERROR, "ff_get_format failed: %d\n", surface_fmt);
         ctx->internal_error = AVERROR(EINVAL);
         return 0;
     }
 
     av_log(avctx, AV_LOG_VERBOSE, "Formats: Original: %s | HW: %s | SW: %s\n",
            av_get_pix_fmt_name(avctx->pix_fmt),
            av_get_pix_fmt_name(surface_fmt),
            av_get_pix_fmt_name(avctx->sw_pix_fmt));
 
     avctx->pix_fmt = surface_fmt;
 

     // Update our hwframe ctx, as the get_format callback might have refreshed it!
     if (avctx->hw_frames_ctx) {
         av_buffer_unref(&ctx->hwframe);
 
         ctx->hwframe = av_buffer_ref(avctx->hw_frames_ctx);
         if (!ctx->hwframe) {
             ctx->internal_error = AVERROR(ENOMEM);
             return 0;
         }
 
         hwframe_ctx = (AVHWFramesContext*)ctx->hwframe->data;
     }
 

     ff_set_sar(avctx, av_div_q(
         (AVRational){ format->display_aspect_ratio.x, format->display_aspect_ratio.y },
         (AVRational){ avctx->width, avctx->height }));
 

     ctx->deint_mode_current = format->progressive_sequence
                               ? cudaVideoDeinterlaceMode_Weave
                               : ctx->deint_mode;
 
     if (!format->progressive_sequence && ctx->deint_mode_current == cudaVideoDeinterlaceMode_Weave)

         avctx->flags |= AV_CODEC_FLAG_INTERLACED_DCT;
     else
         avctx->flags &= ~AV_CODEC_FLAG_INTERLACED_DCT;
 
     if (format->video_signal_description.video_full_range_flag)
         avctx->color_range = AVCOL_RANGE_JPEG;
     else
         avctx->color_range = AVCOL_RANGE_MPEG;
 
     avctx->color_primaries = format->video_signal_description.color_primaries;
     avctx->color_trc = format->video_signal_description.transfer_characteristics;
     avctx->colorspace = format->video_signal_description.matrix_coefficients;
 
     if (format->bitrate)
         avctx->bit_rate = format->bitrate;
 
     if (format->frame_rate.numerator && format->frame_rate.denominator) {
         avctx->framerate.num = format->frame_rate.numerator;
         avctx->framerate.den = format->frame_rate.denominator;
     }
 
     if (ctx->cudecoder
             && avctx->coded_width == format->coded_width
             && avctx->coded_height == format->coded_height

             && avctx->width == old_width
             && avctx->height == old_height

             && ctx->chroma_format == format->chroma_format
             && ctx->codec_type == format->codec)
         return 1;
 
     if (ctx->cudecoder) {

         av_log(avctx, AV_LOG_TRACE, "Re-initializing decoder\n");

         ctx->internal_error = CHECK_CU(ctx->cvdl->cuvidDestroyDecoder(ctx->cudecoder));

         if (ctx->internal_error < 0)
             return 0;
         ctx->cudecoder = NULL;

     }
 

     if (hwframe_ctx->pool && (
             hwframe_ctx->width < avctx->width ||
             hwframe_ctx->height < avctx->height ||
             hwframe_ctx->format != AV_PIX_FMT_CUDA ||

             hwframe_ctx->sw_format != avctx->sw_pix_fmt)) {

         av_log(avctx, AV_LOG_ERROR, "AVHWFramesContext is already initialized with incompatible parameters\n");

         av_log(avctx, AV_LOG_DEBUG, "width: %d <-> %d\n", hwframe_ctx->width, avctx->width);
         av_log(avctx, AV_LOG_DEBUG, "height: %d <-> %d\n", hwframe_ctx->height, avctx->height);
         av_log(avctx, AV_LOG_DEBUG, "format: %s <-> cuda\n", av_get_pix_fmt_name(hwframe_ctx->format));
         av_log(avctx, AV_LOG_DEBUG, "sw_format: %s <-> %s\n",
                av_get_pix_fmt_name(hwframe_ctx->sw_format), av_get_pix_fmt_name(avctx->sw_pix_fmt));

         ctx->internal_error = AVERROR(EINVAL);
         return 0;
     }
 

     if (format->chroma_format != cudaVideoChromaFormat_420) {
         av_log(avctx, AV_LOG_ERROR, "Chroma formats other than 420 are not supported\n");
         ctx->internal_error = AVERROR(EINVAL);
         return 0;
     }
 

     ctx->chroma_format = format->chroma_format;
 
     cuinfo.CodecType = ctx->codec_type = format->codec;
     cuinfo.ChromaFormat = format->chroma_format;

 
     switch (avctx->sw_pix_fmt) {
     case AV_PIX_FMT_NV12:
         cuinfo.OutputFormat = cudaVideoSurfaceFormat_NV12;
         break;
     case AV_PIX_FMT_P010:
     case AV_PIX_FMT_P016:
         cuinfo.OutputFormat = cudaVideoSurfaceFormat_P016;
         break;
     default:
         av_log(avctx, AV_LOG_ERROR, "Output formats other than NV12, P010 or P016 are not supported\n");
         ctx->internal_error = AVERROR(EINVAL);
         return 0;
     }

     cuinfo.ulNumDecodeSurfaces = ctx->nb_surfaces;

     cuinfo.ulNumOutputSurfaces = 1;
     cuinfo.ulCreationFlags = cudaVideoCreate_PreferCUVID;

     cuinfo.bitDepthMinus8 = format->bit_depth_luma_minus8;

     cuinfo.DeinterlaceMode = ctx->deint_mode_current;

     if (ctx->deint_mode_current != cudaVideoDeinterlaceMode_Weave && !ctx->drop_second_field)

         avctx->framerate = av_mul_q(avctx->framerate, (AVRational){2, 1});

     ctx->internal_error = CHECK_CU(ctx->cvdl->cuvidCreateDecoder(&ctx->cudecoder, &cuinfo));

     if (ctx->internal_error < 0)
         return 0;
 

     if (!hwframe_ctx->pool) {
         hwframe_ctx->format = AV_PIX_FMT_CUDA;

         hwframe_ctx->sw_format = avctx->sw_pix_fmt;

         hwframe_ctx->width = avctx->width;
         hwframe_ctx->height = avctx->height;

         if ((ctx->internal_error = av_hwframe_ctx_init(ctx->hwframe)) < 0) {
             av_log(avctx, AV_LOG_ERROR, "av_hwframe_ctx_init failed\n");
             return 0;
         }

     }
 
     return 1;
 }
 
 static int CUDAAPI cuvid_handle_picture_decode(void *opaque, CUVIDPICPARAMS* picparams)
 {
     AVCodecContext *avctx = opaque;
     CuvidContext *ctx = avctx->priv_data;
 
     av_log(avctx, AV_LOG_TRACE, "pfnDecodePicture\n");
 

     ctx->internal_error = CHECK_CU(ctx->cvdl->cuvidDecodePicture(ctx->cudecoder, picparams));

     if (ctx->internal_error < 0)
         return 0;
 
     return 1;
 }
 
 static int CUDAAPI cuvid_handle_picture_display(void *opaque, CUVIDPARSERDISPINFO* dispinfo)
 {
     AVCodecContext *avctx = opaque;
     CuvidContext *ctx = avctx->priv_data;

     CuvidParsedFrame parsed_frame = { { 0 } };

     parsed_frame.dispinfo = *dispinfo;

     ctx->internal_error = 0;
 

     if (ctx->deint_mode_current == cudaVideoDeinterlaceMode_Weave) {

         av_fifo_generic_write(ctx->frame_queue, &parsed_frame, sizeof(CuvidParsedFrame), NULL);
     } else {
         parsed_frame.is_deinterlacing = 1;
         av_fifo_generic_write(ctx->frame_queue, &parsed_frame, sizeof(CuvidParsedFrame), NULL);

         if (!ctx->drop_second_field) {
             parsed_frame.second_field = 1;
             av_fifo_generic_write(ctx->frame_queue, &parsed_frame, sizeof(CuvidParsedFrame), NULL);
         }

     }

 
     return 1;
 }
 

 static int cuvid_decode_packet(AVCodecContext *avctx, const AVPacket *avpkt)

 {
     CuvidContext *ctx = avctx->priv_data;
     AVHWDeviceContext *device_ctx = (AVHWDeviceContext*)ctx->hwdevice->data;
     AVCUDADeviceContext *device_hwctx = device_ctx->hwctx;
     CUcontext dummy, cuda_ctx = device_hwctx->cuda_ctx;
     CUVIDSOURCEDATAPACKET cupkt;
     AVPacket filter_packet = { 0 };
     AVPacket filtered_packet = { 0 };

     int ret = 0, eret = 0, is_flush = ctx->decoder_flushing;

     av_log(avctx, AV_LOG_TRACE, "cuvid_decode_packet\n");
 
     if (is_flush && avpkt && avpkt->size)
         return AVERROR_EOF;
 

     if ((av_fifo_size(ctx->frame_queue) / sizeof(CuvidParsedFrame)) + 2 > ctx->nb_surfaces && avpkt && avpkt->size)

         return AVERROR(EAGAIN);
 
     if (ctx->bsf && avpkt && avpkt->size) {

         if ((ret = av_packet_ref(&filter_packet, avpkt)) < 0) {
             av_log(avctx, AV_LOG_ERROR, "av_packet_ref failed\n");
             return ret;
         }
 
         if ((ret = av_bsf_send_packet(ctx->bsf, &filter_packet)) < 0) {
             av_log(avctx, AV_LOG_ERROR, "av_bsf_send_packet failed\n");
             av_packet_unref(&filter_packet);
             return ret;
         }
 
         if ((ret = av_bsf_receive_packet(ctx->bsf, &filtered_packet)) < 0) {
             av_log(avctx, AV_LOG_ERROR, "av_bsf_receive_packet failed\n");
             return ret;
         }
 
         avpkt = &filtered_packet;
     }
 

     ret = CHECK_CU(ctx->cudl->cuCtxPushCurrent(cuda_ctx));

     if (ret < 0) {
         av_packet_unref(&filtered_packet);
         return ret;
     }
 
     memset(&cupkt, 0, sizeof(cupkt));
 

     if (avpkt && avpkt->size) {

         cupkt.payload_size = avpkt->size;
         cupkt.payload = avpkt->data;
 
         if (avpkt->pts != AV_NOPTS_VALUE) {
             cupkt.flags = CUVID_PKT_TIMESTAMP;

             if (avctx->pkt_timebase.num && avctx->pkt_timebase.den)
                 cupkt.timestamp = av_rescale_q(avpkt->pts, avctx->pkt_timebase, (AVRational){1, 10000000});
             else
                 cupkt.timestamp = avpkt->pts;

         }
     } else {
         cupkt.flags = CUVID_PKT_ENDOFSTREAM;

         ctx->decoder_flushing = 1;

     }
 

     ret = CHECK_CU(ctx->cvdl->cuvidParseVideoData(ctx->cuparser, &cupkt));

 
     av_packet_unref(&filtered_packet);
 

     if (ret < 0)

         goto error;
 
     // cuvidParseVideoData doesn't return an error just because stuff failed...
     if (ctx->internal_error) {
         av_log(avctx, AV_LOG_ERROR, "cuvid decode callback error\n");
         ret = ctx->internal_error;

         goto error;
     }
 

 error:

     eret = CHECK_CU(ctx->cudl->cuCtxPopCurrent(&dummy));

 
     if (eret < 0)
         return eret;
     else if (ret < 0)
         return ret;
     else if (is_flush)
         return AVERROR_EOF;
     else
         return 0;
 }
 
 static int cuvid_output_frame(AVCodecContext *avctx, AVFrame *frame)
 {
     CuvidContext *ctx = avctx->priv_data;
     AVHWDeviceContext *device_ctx = (AVHWDeviceContext*)ctx->hwdevice->data;
     AVCUDADeviceContext *device_hwctx = device_ctx->hwctx;
     CUcontext dummy, cuda_ctx = device_hwctx->cuda_ctx;
     CUdeviceptr mapped_frame = 0;
     int ret = 0, eret = 0;
 
     av_log(avctx, AV_LOG_TRACE, "cuvid_output_frame\n");
 
     if (ctx->decoder_flushing) {
         ret = cuvid_decode_packet(avctx, NULL);
         if (ret < 0 && ret != AVERROR_EOF)
             return ret;
     }
 

     ret = CHECK_CU(ctx->cudl->cuCtxPushCurrent(cuda_ctx));

     if (ret < 0)
         return ret;
 

     if (av_fifo_size(ctx->frame_queue)) {

         CuvidParsedFrame parsed_frame;

         CUVIDPROCPARAMS params;
         unsigned int pitch = 0;
         int offset = 0;
         int i;
 

         av_fifo_generic_read(ctx->frame_queue, &parsed_frame, sizeof(CuvidParsedFrame), NULL);

 
         memset(&params, 0, sizeof(params));

         params.progressive_frame = parsed_frame.dispinfo.progressive_frame;
         params.second_field = parsed_frame.second_field;
         params.top_field_first = parsed_frame.dispinfo.top_field_first;

         ret = CHECK_CU(ctx->cvdl->cuvidMapVideoFrame(ctx->cudecoder, parsed_frame.dispinfo.picture_index, &mapped_frame, &pitch, &params));

         if (ret < 0)
             goto error;
 
         if (avctx->pix_fmt == AV_PIX_FMT_CUDA) {
             ret = av_hwframe_get_buffer(ctx->hwframe, frame, 0);
             if (ret < 0) {
                 av_log(avctx, AV_LOG_ERROR, "av_hwframe_get_buffer failed\n");
                 goto error;
             }
 
             ret = ff_decode_frame_props(avctx, frame);
             if (ret < 0) {
                 av_log(avctx, AV_LOG_ERROR, "ff_decode_frame_props failed\n");
                 goto error;
             }
 
             for (i = 0; i < 2; i++) {
                 CUDA_MEMCPY2D cpy = {
                     .srcMemoryType = CU_MEMORYTYPE_DEVICE,
                     .dstMemoryType = CU_MEMORYTYPE_DEVICE,
                     .srcDevice     = mapped_frame,
                     .dstDevice     = (CUdeviceptr)frame->data[i],
                     .srcPitch      = pitch,
                     .dstPitch      = frame->linesize[i],
                     .srcY          = offset,
                     .WidthInBytes  = FFMIN(pitch, frame->linesize[i]),

                     .Height        = avctx->height >> (i ? 1 : 0),

                 };
 

                 ret = CHECK_CU(ctx->cudl->cuMemcpy2D(&cpy));

                 if (ret < 0)
                     goto error;
 

                 offset += avctx->height;

             }

         } else if (avctx->pix_fmt == AV_PIX_FMT_NV12 ||
                    avctx->pix_fmt == AV_PIX_FMT_P010 ||
                    avctx->pix_fmt == AV_PIX_FMT_P016) {

             AVFrame *tmp_frame = av_frame_alloc();
             if (!tmp_frame) {
                 av_log(avctx, AV_LOG_ERROR, "av_frame_alloc failed\n");
                 ret = AVERROR(ENOMEM);
                 goto error;
             }
 
             tmp_frame->format        = AV_PIX_FMT_CUDA;
             tmp_frame->hw_frames_ctx = av_buffer_ref(ctx->hwframe);
             tmp_frame->data[0]       = (uint8_t*)mapped_frame;
             tmp_frame->linesize[0]   = pitch;

             tmp_frame->data[1]       = (uint8_t*)(mapped_frame + avctx->height * pitch);

             tmp_frame->linesize[1]   = pitch;
             tmp_frame->width         = avctx->width;
             tmp_frame->height        = avctx->height;
 
             ret = ff_get_buffer(avctx, frame, 0);
             if (ret < 0) {
                 av_log(avctx, AV_LOG_ERROR, "ff_get_buffer failed\n");
                 av_frame_free(&tmp_frame);
                 goto error;
             }
 
             ret = av_hwframe_transfer_data(frame, tmp_frame, 0);
             if (ret) {
                 av_log(avctx, AV_LOG_ERROR, "av_hwframe_transfer_data failed\n");
                 av_frame_free(&tmp_frame);
                 goto error;
             }
             av_frame_free(&tmp_frame);
         } else {
             ret = AVERROR_BUG;
             goto error;
         }
 
         frame->width = avctx->width;
         frame->height = avctx->height;

         if (avctx->pkt_timebase.num && avctx->pkt_timebase.den)

             frame->pts = av_rescale_q(parsed_frame.dispinfo.timestamp, (AVRational){1, 10000000}, avctx->pkt_timebase);

         else

             frame->pts = parsed_frame.dispinfo.timestamp;
 
         if (parsed_frame.second_field) {
             if (ctx->prev_pts == INT64_MIN) {
                 ctx->prev_pts = frame->pts;
                 frame->pts += (avctx->pkt_timebase.den * avctx->framerate.den) / (avctx->pkt_timebase.num * avctx->framerate.num);
             } else {
                 int pts_diff = (frame->pts - ctx->prev_pts) / 2;
                 ctx->prev_pts = frame->pts;
                 frame->pts += pts_diff;
             }
         }

 
         /* CUVIDs opaque reordering breaks the internal pkt logic.
          * So set pkt_pts and clear all the other pkt_ fields.
          */

 #if FF_API_PKT_PTS
 FF_DISABLE_DEPRECATION_WARNINGS

         frame->pkt_pts = frame->pts;

 FF_ENABLE_DEPRECATION_WARNINGS
 #endif

         av_frame_set_pkt_pos(frame, -1);
         av_frame_set_pkt_duration(frame, 0);
         av_frame_set_pkt_size(frame, -1);
 

         frame->interlaced_frame = !parsed_frame.is_deinterlacing && !parsed_frame.dispinfo.progressive_frame;

         if (frame->interlaced_frame)
             frame->top_field_first = parsed_frame.dispinfo.top_field_first;

     } else if (ctx->decoder_flushing) {
         ret = AVERROR_EOF;

     } else {

         ret = AVERROR(EAGAIN);

     }
 
 error:
     if (mapped_frame)

         eret = CHECK_CU(ctx->cvdl->cuvidUnmapVideoFrame(ctx->cudecoder, mapped_frame));

     eret = CHECK_CU(ctx->cudl->cuCtxPopCurrent(&dummy));

 
     if (eret < 0)
         return eret;
     else
         return ret;
 }
 

 static int cuvid_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
 {
     CuvidContext *ctx = avctx->priv_data;
     AVFrame *frame = data;
     int ret = 0;
 
     av_log(avctx, AV_LOG_TRACE, "cuvid_decode_frame\n");
 

     if (ctx->deint_mode_current != cudaVideoDeinterlaceMode_Weave) {

         av_log(avctx, AV_LOG_ERROR, "Deinterlacing is not supported via the old API\n");
         return AVERROR(EINVAL);
     }
 

     if (!ctx->decoder_flushing) {
         ret = cuvid_decode_packet(avctx, avpkt);
         if (ret < 0)
             return ret;
     }
 
     ret = cuvid_output_frame(avctx, frame);
     if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF) {
         *got_frame = 0;
     } else if (ret < 0) {
         return ret;
     } else {
         *got_frame = 1;
     }
 
     return 0;
 }
 

 static av_cold int cuvid_decode_end(AVCodecContext *avctx)
 {
     CuvidContext *ctx = avctx->priv_data;
 
     av_fifo_freep(&ctx->frame_queue);
 
     if (ctx->bsf)
         av_bsf_free(&ctx->bsf);
 
     if (ctx->cuparser)

         ctx->cvdl->cuvidDestroyVideoParser(ctx->cuparser);

 
     if (ctx->cudecoder)

         ctx->cvdl->cuvidDestroyDecoder(ctx->cudecoder);
 
     ctx->cudl = NULL;

 
     av_buffer_unref(&ctx->hwframe);
     av_buffer_unref(&ctx->hwdevice);
 

     cuvid_free_functions(&ctx->cvdl);
 

     return 0;
 }
 

 static int cuvid_test_dummy_decoder(AVCodecContext *avctx,
                                     const CUVIDPARSERPARAMS *cuparseinfo,
                                     int probed_width,
                                     int probed_height)

 {

     CuvidContext *ctx = avctx->priv_data;

     CUVIDDECODECREATEINFO cuinfo;
     CUvideodecoder cudec = 0;
     int ret = 0;
 
     memset(&cuinfo, 0, sizeof(cuinfo));
 
     cuinfo.CodecType = cuparseinfo->CodecType;
     cuinfo.ChromaFormat = cudaVideoChromaFormat_420;
     cuinfo.OutputFormat = cudaVideoSurfaceFormat_NV12;
 

     cuinfo.ulWidth = probed_width;
     cuinfo.ulHeight = probed_height;

     cuinfo.ulTargetWidth = cuinfo.ulWidth;
     cuinfo.ulTargetHeight = cuinfo.ulHeight;
 
     cuinfo.target_rect.left = 0;
     cuinfo.target_rect.top = 0;
     cuinfo.target_rect.right = cuinfo.ulWidth;
     cuinfo.target_rect.bottom = cuinfo.ulHeight;
 

     cuinfo.ulNumDecodeSurfaces = ctx->nb_surfaces;

     cuinfo.ulNumOutputSurfaces = 1;
     cuinfo.ulCreationFlags = cudaVideoCreate_PreferCUVID;

     cuinfo.bitDepthMinus8 = 0;

 
     cuinfo.DeinterlaceMode = cudaVideoDeinterlaceMode_Weave;
 

     ret = CHECK_CU(ctx->cvdl->cuvidCreateDecoder(&cudec, &cuinfo));

     if (ret < 0)
         return ret;
 

     ret = CHECK_CU(ctx->cvdl->cuvidDestroyDecoder(cudec));

     if (ret < 0)
         return ret;
 
     return 0;
 }
 
 static av_cold int cuvid_decode_init(AVCodecContext *avctx)
 {
     CuvidContext *ctx = avctx->priv_data;
     AVCUDADeviceContext *device_hwctx;
     AVHWDeviceContext *device_ctx;
     AVHWFramesContext *hwframe_ctx;
     CUVIDSOURCEDATAPACKET seq_pkt;
     CUcontext cuda_ctx = NULL;
     CUcontext dummy;
     const AVBitStreamFilter *bsf;
     int ret = 0;
 

     enum AVPixelFormat pix_fmts[3] = { AV_PIX_FMT_CUDA,
                                        AV_PIX_FMT_NV12,
                                        AV_PIX_FMT_NONE };
 

     int probed_width = avctx->coded_width ? avctx->coded_width : 1280;
     int probed_height = avctx->coded_height ? avctx->coded_height : 720;
 

     // Accelerated transcoding scenarios with 'ffmpeg' require that the
     // pix_fmt be set to AV_PIX_FMT_CUDA early. The sw_pix_fmt, and the
     // pix_fmt for non-accelerated transcoding, do not need to be correct
     // but need to be set to something. We arbitrarily pick NV12.
     ret = ff_get_format(avctx, pix_fmts);
     if (ret < 0) {
         av_log(avctx, AV_LOG_ERROR, "ff_get_format failed: %d\n", ret);
         return ret;
     }
     avctx->pix_fmt = ret;
 

     if (ctx->resize_expr && sscanf(ctx->resize_expr, "%dx%d",
                                    &ctx->resize.width, &ctx->resize.height) != 2) {
         av_log(avctx, AV_LOG_ERROR, "Invalid resize expressions\n");
         ret = AVERROR(EINVAL);
         goto error;
     }
 
     if (ctx->crop_expr && sscanf(ctx->crop_expr, "%dx%dx%dx%d",
                                  &ctx->crop.top, &ctx->crop.bottom,
                                  &ctx->crop.left, &ctx->crop.right) != 4) {
         av_log(avctx, AV_LOG_ERROR, "Invalid cropping expressions\n");
         ret = AVERROR(EINVAL);
         goto error;
     }
 

     ret = cuvid_load_functions(&ctx->cvdl);
     if (ret < 0) {
         av_log(avctx, AV_LOG_ERROR, "Failed loading nvcuvid.\n");
         goto error;
     }

     ctx->frame_queue = av_fifo_alloc(ctx->nb_surfaces * sizeof(CuvidParsedFrame));

     if (!ctx->frame_queue) {
         ret = AVERROR(ENOMEM);
         goto error;
     }
 
     if (avctx->hw_frames_ctx) {
         ctx->hwframe = av_buffer_ref(avctx->hw_frames_ctx);
         if (!ctx->hwframe) {
             ret = AVERROR(ENOMEM);
             goto error;
         }
 
         hwframe_ctx = (AVHWFramesContext*)ctx->hwframe->data;
 
         ctx->hwdevice = av_buffer_ref(hwframe_ctx->device_ref);
         if (!ctx->hwdevice) {
             ret = AVERROR(ENOMEM);
             goto error;
         }
     } else {

         ret = av_hwdevice_ctx_create(&ctx->hwdevice, AV_HWDEVICE_TYPE_CUDA, ctx->cu_gpu, NULL, 0);

         if (ret < 0)
             goto error;
 
         ctx->hwframe = av_hwframe_ctx_alloc(ctx->hwdevice);
         if (!ctx->hwframe) {
             av_log(avctx, AV_LOG_ERROR, "av_hwframe_ctx_alloc failed\n");
             ret = AVERROR(ENOMEM);
             goto error;
         }

 
         hwframe_ctx = (AVHWFramesContext*)ctx->hwframe->data;

     }
 

     device_ctx = hwframe_ctx->device_ctx;
     device_hwctx = device_ctx->hwctx;

     cuda_ctx = device_hwctx->cuda_ctx;

     ctx->cudl = device_hwctx->internal->cuda_dl;

     memset(&ctx->cuparseinfo, 0, sizeof(ctx->cuparseinfo));
     memset(&ctx->cuparse_ext, 0, sizeof(ctx->cuparse_ext));

     memset(&seq_pkt, 0, sizeof(seq_pkt));
 

     ctx->cuparseinfo.pExtVideoInfo = &ctx->cuparse_ext;

 
     switch (avctx->codec->id) {
 #if CONFIG_H264_CUVID_DECODER
     case AV_CODEC_ID_H264:

         ctx->cuparseinfo.CodecType = cudaVideoCodec_H264;

         break;
 #endif
 #if CONFIG_HEVC_CUVID_DECODER
     case AV_CODEC_ID_HEVC:

         ctx->cuparseinfo.CodecType = cudaVideoCodec_HEVC;

         break;
 #endif

 #if CONFIG_MJPEG_CUVID_DECODER
     case AV_CODEC_ID_MJPEG:

         ctx->cuparseinfo.CodecType = cudaVideoCodec_JPEG;

         break;
 #endif
 #if CONFIG_MPEG1_CUVID_DECODER
     case AV_CODEC_ID_MPEG1VIDEO:

         ctx->cuparseinfo.CodecType = cudaVideoCodec_MPEG1;

         break;
 #endif
 #if CONFIG_MPEG2_CUVID_DECODER
     case AV_CODEC_ID_MPEG2VIDEO:

         ctx->cuparseinfo.CodecType = cudaVideoCodec_MPEG2;

         break;
 #endif
 #if CONFIG_MPEG4_CUVID_DECODER
     case AV_CODEC_ID_MPEG4:

         ctx->cuparseinfo.CodecType = cudaVideoCodec_MPEG4;

         break;
 #endif

 #if CONFIG_VP8_CUVID_DECODER
     case AV_CODEC_ID_VP8:

         ctx->cuparseinfo.CodecType = cudaVideoCodec_VP8;

         break;
 #endif
 #if CONFIG_VP9_CUVID_DECODER
     case AV_CODEC_ID_VP9:

         ctx->cuparseinfo.CodecType = cudaVideoCodec_VP9;

         break;
 #endif
 #if CONFIG_VC1_CUVID_DECODER
     case AV_CODEC_ID_VC1:

         ctx->cuparseinfo.CodecType = cudaVideoCodec_VC1;

         break;
 #endif
     default:
         av_log(avctx, AV_LOG_ERROR, "Invalid CUVID codec!\n");
         return AVERROR_BUG;
     }
 
     if (avctx->codec->id == AV_CODEC_ID_H264 || avctx->codec->id == AV_CODEC_ID_HEVC) {
         if (avctx->codec->id == AV_CODEC_ID_H264)
             bsf = av_bsf_get_by_name("h264_mp4toannexb");
         else
             bsf = av_bsf_get_by_name("hevc_mp4toannexb");
 
         if (!bsf) {
             ret = AVERROR_BSF_NOT_FOUND;
             goto error;
         }
         if (ret = av_bsf_alloc(bsf, &ctx->bsf)) {
             goto error;
         }
         if (((ret = avcodec_parameters_from_context(ctx->bsf->par_in, avctx)) < 0) || ((ret = av_bsf_init(ctx->bsf)) < 0)) {
             av_bsf_free(&ctx->bsf);
             goto error;
         }
 

         ctx->cuparse_ext.format.seqhdr_data_length = ctx->bsf->par_out->extradata_size;
         memcpy(ctx->cuparse_ext.raw_seqhdr_data,

                ctx->bsf->par_out->extradata,

                FFMIN(sizeof(ctx->cuparse_ext.raw_seqhdr_data), ctx->bsf->par_out->extradata_size));

     } else if (avctx->extradata_size > 0) {

         ctx->cuparse_ext.format.seqhdr_data_length = avctx->extradata_size;
         memcpy(ctx->cuparse_ext.raw_seqhdr_data,

                avctx->extradata,

                FFMIN(sizeof(ctx->cuparse_ext.raw_seqhdr_data), avctx->extradata_size));

     }
 

     ctx->cuparseinfo.ulMaxNumDecodeSurfaces = ctx->nb_surfaces;

     ctx->cuparseinfo.ulMaxDisplayDelay = 4;
     ctx->cuparseinfo.pUserData = avctx;
     ctx->cuparseinfo.pfnSequenceCallback = cuvid_handle_video_sequence;
     ctx->cuparseinfo.pfnDecodePicture = cuvid_handle_picture_decode;
     ctx->cuparseinfo.pfnDisplayPicture = cuvid_handle_picture_display;

     ret = CHECK_CU(ctx->cudl->cuCtxPushCurrent(cuda_ctx));

     if (ret < 0)
         goto error;
 

     ret = cuvid_test_dummy_decoder(avctx, &ctx->cuparseinfo,
                                    probed_width,
                                    probed_height);

     if (ret < 0)
         goto error;
 

     ret = CHECK_CU(ctx->cvdl->cuvidCreateVideoParser(&ctx->cuparser, &ctx->cuparseinfo));

     if (ret < 0)
         goto error;
 

     seq_pkt.payload = ctx->cuparse_ext.raw_seqhdr_data;
     seq_pkt.payload_size = ctx->cuparse_ext.format.seqhdr_data_length;

 
     if (seq_pkt.payload && seq_pkt.payload_size) {

         ret = CHECK_CU(ctx->cvdl->cuvidParseVideoData(ctx->cuparser, &seq_pkt));

         if (ret < 0)
             goto error;
     }
 

     ret = CHECK_CU(ctx->cudl->cuCtxPopCurrent(&dummy));

     if (ret < 0)
         goto error;
 

     ctx->prev_pts = INT64_MIN;
 

     if (!avctx->pkt_timebase.num || !avctx->pkt_timebase.den)
         av_log(avctx, AV_LOG_WARNING, "Invalid pkt_timebase, passing timestamps as-is.\n");
 

     return 0;
 
 error:
     cuvid_decode_end(avctx);
     return ret;
 }
 

 static void cuvid_flush(AVCodecContext *avctx)
 {
     CuvidContext *ctx = avctx->priv_data;
     AVHWDeviceContext *device_ctx = (AVHWDeviceContext*)ctx->hwdevice->data;
     AVCUDADeviceContext *device_hwctx = device_ctx->hwctx;
     CUcontext dummy, cuda_ctx = device_hwctx->cuda_ctx;

     CUVIDSOURCEDATAPACKET seq_pkt = { 0 };

     int ret;
 

     ret = CHECK_CU(ctx->cudl->cuCtxPushCurrent(cuda_ctx));

     if (ret < 0)
         goto error;
 
     av_fifo_freep(&ctx->frame_queue);
 

     ctx->frame_queue = av_fifo_alloc(ctx->nb_surfaces * sizeof(CuvidParsedFrame));

     if (!ctx->frame_queue) {
         av_log(avctx, AV_LOG_ERROR, "Failed to recreate frame queue on flush\n");
         return;
     }
 
     if (ctx->cudecoder) {

         ctx->cvdl->cuvidDestroyDecoder(ctx->cudecoder);

         ctx->cudecoder = NULL;
     }
 
     if (ctx->cuparser) {

         ctx->cvdl->cuvidDestroyVideoParser(ctx->cuparser);

         ctx->cuparser = NULL;
     }
 

     ret = CHECK_CU(ctx->cvdl->cuvidCreateVideoParser(&ctx->cuparser, &ctx->cuparseinfo));

     if (ret < 0)
         goto error;
 

     seq_pkt.payload = ctx->cuparse_ext.raw_seqhdr_data;
     seq_pkt.payload_size = ctx->cuparse_ext.format.seqhdr_data_length;
 
     if (seq_pkt.payload && seq_pkt.payload_size) {

         ret = CHECK_CU(ctx->cvdl->cuvidParseVideoData(ctx->cuparser, &seq_pkt));

         if (ret < 0)
             goto error;
     }
 

     ret = CHECK_CU(ctx->cudl->cuCtxPopCurrent(&dummy));

     if (ret < 0)
         goto error;
 

     ctx->prev_pts = INT64_MIN;
     ctx->decoder_flushing = 0;
 

     return;
  error:
     av_log(avctx, AV_LOG_ERROR, "CUDA reinit on flush failed\n");
 }
 

 #define OFFSET(x) offsetof(CuvidContext, x)
 #define VD AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_DECODING_PARAM
 static const AVOption options[] = {
     { "deint",    "Set deinterlacing mode", OFFSET(deint_mode), AV_OPT_TYPE_INT,   { .i64 = cudaVideoDeinterlaceMode_Weave    }, cudaVideoDeinterlaceMode_Weave, cudaVideoDeinterlaceMode_Adaptive, VD, "deint" },
     { "weave",    "Weave deinterlacing (do nothing)",        0, AV_OPT_TYPE_CONST, { .i64 = cudaVideoDeinterlaceMode_Weave    }, 0, 0, VD, "deint" },
     { "bob",      "Bob deinterlacing",                       0, AV_OPT_TYPE_CONST, { .i64 = cudaVideoDeinterlaceMode_Bob      }, 0, 0, VD, "deint" },
     { "adaptive", "Adaptive deinterlacing",                  0, AV_OPT_TYPE_CONST, { .i64 = cudaVideoDeinterlaceMode_Adaptive }, 0, 0, VD, "deint" },

     { "gpu",      "GPU to be used for decoding", OFFSET(cu_gpu), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, VD },

     { "surfaces", "Maximum surfaces to be used for decoding", OFFSET(nb_surfaces), AV_OPT_TYPE_INT, { .i64 = 25 }, 0, INT_MAX, VD },

     { "drop_second_field", "Drop second field when deinterlacing", OFFSET(drop_second_field), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, VD },

     { "crop",     "Crop (top)x(bottom)x(left)x(right)", OFFSET(crop_expr), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, VD },
     { "resize",   "Resize (width)x(height)", OFFSET(resize_expr), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, VD },

     { NULL }
 };
 

 #define DEFINE_CUVID_CODEC(x, X) \

     static const AVClass x##_cuvid_class = { \
         .class_name = #x "_cuvid", \
         .item_name = av_default_item_name, \
         .option = options, \
         .version = LIBAVUTIL_VERSION_INT, \
     }; \

     AVHWAccel ff_##x##_cuvid_hwaccel = { \
         .name           = #x "_cuvid", \
         .type           = AVMEDIA_TYPE_VIDEO, \
         .id             = AV_CODEC_ID_##X, \
         .pix_fmt        = AV_PIX_FMT_CUDA, \
     }; \
     AVCodec ff_##x##_cuvid_decoder = { \
         .name           = #x "_cuvid", \
         .long_name      = NULL_IF_CONFIG_SMALL("Nvidia CUVID " #X " decoder"), \
         .type           = AVMEDIA_TYPE_VIDEO, \
         .id             = AV_CODEC_ID_##X, \
         .priv_data_size = sizeof(CuvidContext), \

         .priv_class     = &x##_cuvid_class, \

         .init           = cuvid_decode_init, \
         .close          = cuvid_decode_end, \
         .decode         = cuvid_decode_frame, \

         .send_packet    = cuvid_decode_packet, \
         .receive_frame  = cuvid_output_frame, \

         .flush          = cuvid_flush, \

         .capabilities   = AV_CODEC_CAP_DELAY | AV_CODEC_CAP_AVOID_PROBING, \

         .pix_fmts       = (const enum AVPixelFormat[]){ AV_PIX_FMT_CUDA, \
                                                         AV_PIX_FMT_NV12, \

                                                         AV_PIX_FMT_P010, \
                                                         AV_PIX_FMT_P016, \

                                                         AV_PIX_FMT_NONE }, \
     };
 
 #if CONFIG_HEVC_CUVID_DECODER
 DEFINE_CUVID_CODEC(hevc, HEVC)
 #endif
 
 #if CONFIG_H264_CUVID_DECODER
 DEFINE_CUVID_CODEC(h264, H264)
 #endif
 

 #if CONFIG_MJPEG_CUVID_DECODER
 DEFINE_CUVID_CODEC(mjpeg, MJPEG)
 #endif
 
 #if CONFIG_MPEG1_CUVID_DECODER
 DEFINE_CUVID_CODEC(mpeg1, MPEG1VIDEO)
 #endif
 
 #if CONFIG_MPEG2_CUVID_DECODER
 DEFINE_CUVID_CODEC(mpeg2, MPEG2VIDEO)
 #endif
 
 #if CONFIG_MPEG4_CUVID_DECODER
 DEFINE_CUVID_CODEC(mpeg4, MPEG4)
 #endif
 

 #if CONFIG_VP8_CUVID_DECODER
 DEFINE_CUVID_CODEC(vp8, VP8)
 #endif
 
 #if CONFIG_VP9_CUVID_DECODER
 DEFINE_CUVID_CODEC(vp9, VP9)
 #endif
 
 #if CONFIG_VC1_CUVID_DECODER
 DEFINE_CUVID_CODEC(vc1, VC1)
 #endif