/*

  * MPEG-1/2 HW decode acceleration through NVDEC

  *
  * Copyright (c) 2017 Philip Langdale
  *
  * 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 "avcodec.h"
 #include "mpegvideo.h"
 #include "nvdec.h"
 #include "decode.h"
 
 static int nvdec_mpeg12_start_frame(AVCodecContext *avctx, const uint8_t *buffer, uint32_t size)
 {
     MpegEncContext *s = avctx->priv_data;
 
     NVDECContext      *ctx = avctx->internal->hwaccel_priv_data;
     CUVIDPICPARAMS     *pp = &ctx->pic_params;
     CUVIDMPEG2PICPARAMS *ppc = &pp->CodecSpecific.mpeg2;
     FrameDecodeData *fdd;
     NVDECFrame *cf;
     AVFrame *cur_frame = s->current_picture.f;
 
     int ret, i;
 
     ret = ff_nvdec_start_frame(avctx, cur_frame);
     if (ret < 0)
         return ret;
 
     fdd = (FrameDecodeData*)cur_frame->private_ref->data;
     cf  = (NVDECFrame*)fdd->hwaccel_priv;
 
     *pp = (CUVIDPICPARAMS) {
         .PicWidthInMbs     = (cur_frame->width  + 15) / 16,
         .FrameHeightInMbs  = (cur_frame->height + 15) / 16,
         .CurrPicIdx        = cf->idx,
 

         .field_pic_flag    = s->picture_structure != PICT_FRAME,
         .bottom_field_flag = s->picture_structure == PICT_BOTTOM_FIELD,
         .second_field      = s->picture_structure != PICT_FRAME && !s->first_field,
 

         .intra_pic_flag    = s->pict_type == AV_PICTURE_TYPE_I,
         .ref_pic_flag      = s->pict_type == AV_PICTURE_TYPE_I ||
                              s->pict_type == AV_PICTURE_TYPE_P,
 
         .CodecSpecific.mpeg2 = {

             .ForwardRefIdx     = ff_nvdec_get_ref_idx(s->last_picture.f),
             .BackwardRefIdx    = ff_nvdec_get_ref_idx(s->next_picture.f),

 
             .picture_coding_type        = s->pict_type,
             .full_pel_forward_vector    = s->full_pel[0],
             .full_pel_backward_vector   = s->full_pel[1],
             .f_code                     = { { s->mpeg_f_code[0][0],
                                               s->mpeg_f_code[0][1] },
                                             { s->mpeg_f_code[1][0],
                                               s->mpeg_f_code[1][1] } },
             .intra_dc_precision         = s->intra_dc_precision,
             .frame_pred_frame_dct       = s->frame_pred_frame_dct,
             .concealment_motion_vectors = s->concealment_motion_vectors,
             .q_scale_type               = s->q_scale_type,
             .intra_vlc_format           = s->intra_vlc_format,
             .alternate_scan             = s->alternate_scan,
             .top_field_first            = s->top_field_first,
         }
     };
 
     for (i = 0; i < 64; ++i) {
         ppc->QuantMatrixIntra[i] = s->intra_matrix[i];
         ppc->QuantMatrixInter[i] = s->inter_matrix[i];
     }
 
     return 0;
 }
 
 static int nvdec_mpeg12_frame_params(AVCodecContext *avctx,
                                   AVBufferRef *hw_frames_ctx)
 {
     // Each frame can at most have one P and one B reference

     return ff_nvdec_frame_params(avctx, hw_frames_ctx, 2, 0);

 }
 
 #if CONFIG_MPEG2_NVDEC_HWACCEL

 const AVHWAccel ff_mpeg2_nvdec_hwaccel = {

     .name                 = "mpeg2_nvdec",
     .type                 = AVMEDIA_TYPE_VIDEO,
     .id                   = AV_CODEC_ID_MPEG2VIDEO,
     .pix_fmt              = AV_PIX_FMT_CUDA,
     .start_frame          = nvdec_mpeg12_start_frame,

     .end_frame            = ff_nvdec_simple_end_frame,
     .decode_slice         = ff_nvdec_simple_decode_slice,

     .frame_params         = nvdec_mpeg12_frame_params,
     .init                 = ff_nvdec_decode_init,
     .uninit               = ff_nvdec_decode_uninit,
     .priv_data_size       = sizeof(NVDECContext),
 };
 #endif

 
 #if CONFIG_MPEG1_NVDEC_HWACCEL

 const AVHWAccel ff_mpeg1_nvdec_hwaccel = {

     .name                 = "mpeg1_nvdec",
     .type                 = AVMEDIA_TYPE_VIDEO,
     .id                   = AV_CODEC_ID_MPEG1VIDEO,
     .pix_fmt              = AV_PIX_FMT_CUDA,
     .start_frame          = nvdec_mpeg12_start_frame,
     .end_frame            = ff_nvdec_simple_end_frame,
     .decode_slice         = ff_nvdec_simple_decode_slice,
     .frame_params         = nvdec_mpeg12_frame_params,
     .init                 = ff_nvdec_decode_init,
     .uninit               = ff_nvdec_decode_uninit,
     .priv_data_size       = sizeof(NVDECContext),
 };
 #endif