/*
  * MPEG-2 HW acceleration.
  *
  * copyright (c) 2010 Laurent Aimar
  *
  * 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 "dxva2_internal.h"
 
 #define MAX_SLICES (SLICE_MAX_START_CODE - SLICE_MIN_START_CODE + 1)
 struct dxva2_picture_context {
     DXVA_PictureParameters pp;
     DXVA_QmatrixData       qm;
     unsigned               slice_count;
     DXVA_SliceInfo         slice[MAX_SLICES];
 
     const uint8_t          *bitstream;
     unsigned               bitstream_size;
 };
 
 static void fill_picture_parameters(AVCodecContext *avctx,
                                     struct dxva_context *ctx,
                                     const struct MpegEncContext *s,
                                     DXVA_PictureParameters *pp)
 {
     const Picture *current_picture = s->current_picture_ptr;
     int is_field = s->picture_structure != PICT_FRAME;
 
     memset(pp, 0, sizeof(*pp));
     pp->wDecodedPictureIndex         = ff_dxva2_get_surface_index(ctx, current_picture);
     pp->wDeblockedPictureIndex       = 0;

     if (s->pict_type != AV_PICTURE_TYPE_I)

         pp->wForwardRefPictureIndex  = ff_dxva2_get_surface_index(ctx, &s->last_picture);
     else
         pp->wForwardRefPictureIndex  = 0xffff;

     if (s->pict_type == AV_PICTURE_TYPE_B)

         pp->wBackwardRefPictureIndex = ff_dxva2_get_surface_index(ctx, &s->next_picture);
     else
         pp->wBackwardRefPictureIndex = 0xffff;
     pp->wPicWidthInMBminus1          = s->mb_width  - 1;
     pp->wPicHeightInMBminus1         = (s->mb_height >> is_field) - 1;
     pp->bMacroblockWidthMinus1       = 15;
     pp->bMacroblockHeightMinus1      = 15;
     pp->bBlockWidthMinus1            = 7;
     pp->bBlockHeightMinus1           = 7;
     pp->bBPPminus1                   = 7;
     pp->bPicStructure                = s->picture_structure;
     pp->bSecondField                 = is_field && !s->first_field;

     pp->bPicIntra                    = s->pict_type == AV_PICTURE_TYPE_I;
     pp->bPicBackwardPrediction       = s->pict_type == AV_PICTURE_TYPE_B;

     pp->bBidirectionalAveragingMode  = 0;
     pp->bMVprecisionAndChromaRelation= 0; /* FIXME */
     pp->bChromaFormat                = s->chroma_format;
     pp->bPicScanFixed                = 1;
     pp->bPicScanMethod               = s->alternate_scan ? 1 : 0;
     pp->bPicReadbackRequests         = 0;
     pp->bRcontrol                    = 0;
     pp->bPicSpatialResid8            = 0;
     pp->bPicOverflowBlocks           = 0;
     pp->bPicExtrapolation            = 0;
     pp->bPicDeblocked                = 0;
     pp->bPicDeblockConfined          = 0;
     pp->bPic4MVallowed               = 0;
     pp->bPicOBMC                     = 0;
     pp->bPicBinPB                    = 0;
     pp->bMV_RPS                      = 0;
     pp->bReservedBits                = 0;
     pp->wBitstreamFcodes             = (s->mpeg_f_code[0][0] << 12) |
                                        (s->mpeg_f_code[0][1] <<  8) |
                                        (s->mpeg_f_code[1][0] <<  4) |
                                        (s->mpeg_f_code[1][1]      );
     pp->wBitstreamPCEelements        = (s->intra_dc_precision         << 14) |
                                        (s->picture_structure          << 12) |
                                        (s->top_field_first            << 11) |
                                        (s->frame_pred_frame_dct       << 10) |
                                        (s->concealment_motion_vectors <<  9) |
                                        (s->q_scale_type               <<  8) |
                                        (s->intra_vlc_format           <<  7) |
                                        (s->alternate_scan             <<  6) |
                                        (s->repeat_first_field         <<  5) |
                                        (s->chroma_420_type            <<  4) |
                                        (s->progressive_frame          <<  3);
     pp->bBitstreamConcealmentNeed    = 0;
     pp->bBitstreamConcealmentMethod  = 0;
 }
 
 static void fill_quantization_matrices(AVCodecContext *avctx,
                                        struct dxva_context *ctx,
                                        const struct MpegEncContext *s,
                                        DXVA_QmatrixData *qm)
 {
     int i;
     for (i = 0; i < 4; i++)
         qm->bNewQmatrix[i] = 1;
     for (i = 0; i < 64; i++) {
         int n = s->dsp.idct_permutation[ff_zigzag_direct[i]];
         qm->Qmatrix[0][i] = s->intra_matrix[n];;
         qm->Qmatrix[1][i] = s->inter_matrix[n];;
         qm->Qmatrix[2][i] = s->chroma_intra_matrix[n];;
         qm->Qmatrix[3][i] = s->chroma_inter_matrix[n];;
     }
 }
 
 static void fill_slice(AVCodecContext *avctx,
                        const struct MpegEncContext *s,
                        DXVA_SliceInfo *slice,
                        unsigned position,
                        const uint8_t *buffer, unsigned size)
 {
     int is_field = s->picture_structure != PICT_FRAME;
     GetBitContext gb;
 
     memset(slice, 0, sizeof(*slice));
     slice->wHorizontalPosition = s->mb_x;
     slice->wVerticalPosition   = s->mb_y >> is_field;
     slice->dwSliceBitsInBuffer = 8 * size;
     slice->dwSliceDataLocation = position;
     slice->bStartCodeBitOffset = 0;
     slice->bReservedBits       = 0;
     /* XXX We store the index of the first MB and it will be fixed later */
     slice->wNumberMBsInSlice   = (s->mb_y >> is_field) * s->mb_width + s->mb_x;
     slice->wBadSliceChopping   = 0;
 
     init_get_bits(&gb, &buffer[4], 8 * (size - 4));
 
     slice->wQuantizerScaleCode = get_bits(&gb, 5);
     while (get_bits1(&gb))
         skip_bits(&gb, 8);
 
     slice->wMBbitOffset        = 4 * 8 + get_bits_count(&gb);
 }
 static int commit_bitstream_and_slice_buffer(AVCodecContext *avctx,
                                              DXVA2_DecodeBufferDesc *bs,
                                              DXVA2_DecodeBufferDesc *sc)
 {
     const struct MpegEncContext *s = avctx->priv_data;
     struct dxva_context *ctx = avctx->hwaccel_context;
     struct dxva2_picture_context *ctx_pic =
         s->current_picture_ptr->hwaccel_picture_private;
     const int is_field = s->picture_structure != PICT_FRAME;
     const unsigned mb_count = s->mb_width * (s->mb_height >> is_field);
     uint8_t  *dxva_data, *current, *end;
     unsigned dxva_size;
     unsigned i;
 
     if (FAILED(IDirectXVideoDecoder_GetBuffer(ctx->decoder,
                                               DXVA2_BitStreamDateBufferType,
                                               &dxva_data, &dxva_size)))
         return -1;
     current = dxva_data;
     end = dxva_data + dxva_size;
 
     for (i = 0; i < ctx_pic->slice_count; i++) {
         DXVA_SliceInfo *slice = &ctx_pic->slice[i];
         unsigned position = slice->dwSliceDataLocation;
         unsigned size     = slice->dwSliceBitsInBuffer / 8;
         if (size > end - current) {
             av_log(avctx, AV_LOG_ERROR, "Failed to build bitstream");
             break;
         }
         slice->dwSliceDataLocation = current - dxva_data;
 
         if (i < ctx_pic->slice_count - 1)
             slice->wNumberMBsInSlice =
                 slice[1].wNumberMBsInSlice - slice[0].wNumberMBsInSlice;
         else
             slice->wNumberMBsInSlice =
                 mb_count - slice[0].wNumberMBsInSlice;
 
         memcpy(current, &ctx_pic->bitstream[position], size);
         current += size;
     }
     if (FAILED(IDirectXVideoDecoder_ReleaseBuffer(ctx->decoder,
                                                   DXVA2_BitStreamDateBufferType)))
         return -1;
     if (i < ctx_pic->slice_count)
         return -1;
 
     memset(bs, 0, sizeof(*bs));
     bs->CompressedBufferType = DXVA2_BitStreamDateBufferType;
     bs->DataSize             = current - dxva_data;
     bs->NumMBsInBuffer       = mb_count;
 
     return ff_dxva2_commit_buffer(avctx, ctx, sc,
                                   DXVA2_SliceControlBufferType,
                                   ctx_pic->slice,
                                   ctx_pic->slice_count * sizeof(*ctx_pic->slice),
                                   mb_count);
 }
 
 static int start_frame(AVCodecContext *avctx,
                        av_unused const uint8_t *buffer,
                        av_unused uint32_t size)
 {
     const struct MpegEncContext *s = avctx->priv_data;
     struct dxva_context *ctx = avctx->hwaccel_context;
     struct dxva2_picture_context *ctx_pic =
         s->current_picture_ptr->hwaccel_picture_private;
 
     if (!ctx->decoder || !ctx->cfg || ctx->surface_count <= 0)
         return -1;
     assert(ctx_pic);
 
     fill_picture_parameters(avctx, ctx, s, &ctx_pic->pp);
     fill_quantization_matrices(avctx, ctx, s, &ctx_pic->qm);
 
     ctx_pic->slice_count    = 0;
     ctx_pic->bitstream_size = 0;
     ctx_pic->bitstream      = NULL;
     return 0;
 }
 
 static int decode_slice(AVCodecContext *avctx,
                         const uint8_t *buffer, uint32_t size)
 {
     const struct MpegEncContext *s = avctx->priv_data;
     struct dxva2_picture_context *ctx_pic =
         s->current_picture_ptr->hwaccel_picture_private;
     unsigned position;
 
     if (ctx_pic->slice_count >= MAX_SLICES)
         return -1;
 
     if (!ctx_pic->bitstream)
         ctx_pic->bitstream = buffer;
     ctx_pic->bitstream_size += size;
 
     position = buffer - ctx_pic->bitstream;
     fill_slice(avctx, s, &ctx_pic->slice[ctx_pic->slice_count++], position,
                buffer, size);
     return 0;
 }
 
 static int end_frame(AVCodecContext *avctx)
 {
     struct MpegEncContext *s = avctx->priv_data;
     struct dxva2_picture_context *ctx_pic =
         s->current_picture_ptr->hwaccel_picture_private;
 
     if (ctx_pic->slice_count <= 0 || ctx_pic->bitstream_size <= 0)
         return -1;
     return ff_dxva2_common_end_frame(avctx, s,
                                      &ctx_pic->pp, sizeof(ctx_pic->pp),
                                      &ctx_pic->qm, sizeof(ctx_pic->qm),
                                      commit_bitstream_and_slice_buffer);
 }
 

 AVHWAccel ff_mpeg2_dxva2_hwaccel = {

     .name           = "mpeg2_dxva2",
     .type           = AVMEDIA_TYPE_VIDEO,
     .id             = CODEC_ID_MPEG2VIDEO,
     .pix_fmt        = PIX_FMT_DXVA2_VLD,
     .capabilities   = 0,
     .start_frame    = start_frame,
     .decode_slice   = decode_slice,
     .end_frame      = end_frame,
     .priv_data_size = sizeof(struct dxva2_picture_context),
 };