/*
  * MPEG-2 HW decode acceleration through VA API
  *
  * Copyright (C) 2008-2009 Splitted-Desktop Systems
  *
  * 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 "mpegutils.h"

 #include "vaapi_internal.h"

 #include "internal.h"

 
 /** Reconstruct bitstream f_code */
 static inline int mpeg2_get_f_code(MpegEncContext *s)
 {

     return (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];

 }
 
 /** Determine frame start: first field for field picture or frame picture */
 static inline int mpeg2_get_is_frame_start(MpegEncContext *s)
 {
     return s->first_field || s->picture_structure == PICT_FRAME;
 }
 
 static int vaapi_mpeg2_start_frame(AVCodecContext *avctx, av_unused const uint8_t *buffer, av_unused uint32_t size)
 {
     struct MpegEncContext * const s = avctx->priv_data;

     FFVAContext * const vactx = ff_vaapi_get_context(avctx);

     VAPictureParameterBufferMPEG2 *pic_param;
     VAIQMatrixBufferMPEG2 *iq_matrix;
     int i;
 

     ff_dlog(avctx, "vaapi_mpeg2_start_frame()\n");

 
     vactx->slice_param_size = sizeof(VASliceParameterBufferMPEG2);
 
     /* Fill in VAPictureParameterBufferMPEG2 */

     pic_param = ff_vaapi_alloc_pic_param(vactx, sizeof(VAPictureParameterBufferMPEG2));

     if (!pic_param)
         return -1;

     pic_param->horizontal_size                                  = s->width;
     pic_param->vertical_size                                    = s->height;

     pic_param->forward_reference_picture                        = VA_INVALID_ID;
     pic_param->backward_reference_picture                       = VA_INVALID_ID;

     pic_param->picture_coding_type                              = s->pict_type;
     pic_param->f_code                                           = mpeg2_get_f_code(s);
     pic_param->picture_coding_extension.value                   = 0; /* reset all bits */
     pic_param->picture_coding_extension.bits.intra_dc_precision = s->intra_dc_precision;
     pic_param->picture_coding_extension.bits.picture_structure  = s->picture_structure;
     pic_param->picture_coding_extension.bits.top_field_first    = s->top_field_first;
     pic_param->picture_coding_extension.bits.frame_pred_frame_dct = s->frame_pred_frame_dct;
     pic_param->picture_coding_extension.bits.concealment_motion_vectors = s->concealment_motion_vectors;
     pic_param->picture_coding_extension.bits.q_scale_type       = s->q_scale_type;
     pic_param->picture_coding_extension.bits.intra_vlc_format   = s->intra_vlc_format;
     pic_param->picture_coding_extension.bits.alternate_scan     = s->alternate_scan;
     pic_param->picture_coding_extension.bits.repeat_first_field = s->repeat_first_field;
     pic_param->picture_coding_extension.bits.progressive_frame  = s->progressive_frame;
     pic_param->picture_coding_extension.bits.is_first_field     = mpeg2_get_is_frame_start(s);
 
     switch (s->pict_type) {

     case AV_PICTURE_TYPE_B:

         pic_param->backward_reference_picture = ff_vaapi_get_surface_id(s->next_picture.f);

         // fall-through

     case AV_PICTURE_TYPE_P:

         pic_param->forward_reference_picture = ff_vaapi_get_surface_id(s->last_picture.f);

         break;
     }
 
     /* Fill in VAIQMatrixBufferMPEG2 */

     iq_matrix = ff_vaapi_alloc_iq_matrix(vactx, sizeof(VAIQMatrixBufferMPEG2));
     if (!iq_matrix)
         return -1;

     iq_matrix->load_intra_quantiser_matrix              = 1;
     iq_matrix->load_non_intra_quantiser_matrix          = 1;
     iq_matrix->load_chroma_intra_quantiser_matrix       = 1;
     iq_matrix->load_chroma_non_intra_quantiser_matrix   = 1;
 
     for (i = 0; i < 64; i++) {

         int n = s->idsp.idct_permutation[ff_zigzag_direct[i]];

         iq_matrix->intra_quantiser_matrix[i]            = s->intra_matrix[n];
         iq_matrix->non_intra_quantiser_matrix[i]        = s->inter_matrix[n];
         iq_matrix->chroma_intra_quantiser_matrix[i]     = s->chroma_intra_matrix[n];
         iq_matrix->chroma_non_intra_quantiser_matrix[i] = s->chroma_inter_matrix[n];
     }
     return 0;
 }
 
 static int vaapi_mpeg2_decode_slice(AVCodecContext *avctx, const uint8_t *buffer, uint32_t size)
 {
     MpegEncContext * const s = avctx->priv_data;

     FFVAContext * const vactx = ff_vaapi_get_context(avctx);

     VASliceParameterBufferMPEG2 *slice_param;
     GetBitContext gb;

     uint32_t quantiser_scale_code, intra_slice_flag, macroblock_offset;

     ff_dlog(avctx, "vaapi_mpeg2_decode_slice(): buffer %p, size %d\n", buffer, size);

 
     /* Determine macroblock_offset */
     init_get_bits(&gb, buffer, 8 * size);

     if (get_bits_long(&gb, 32) >> 8 != 1) /* start code */
         return AVERROR_INVALIDDATA;

     quantiser_scale_code = get_bits(&gb, 5);
     intra_slice_flag = get_bits1(&gb);
     if (intra_slice_flag) {
         skip_bits(&gb, 8);

         if (skip_1stop_8data_bits(&gb) < 0)
             return AVERROR_INVALIDDATA;

     }
     macroblock_offset = get_bits_count(&gb);
 
     /* Fill in VASliceParameterBufferMPEG2 */

     slice_param = (VASliceParameterBufferMPEG2 *)ff_vaapi_alloc_slice(vactx, buffer, size);

     if (!slice_param)
         return -1;
     slice_param->macroblock_offset              = macroblock_offset;

     slice_param->slice_horizontal_position      = s->mb_x;

     slice_param->slice_vertical_position        = s->mb_y >> (s->picture_structure != PICT_FRAME);

     slice_param->quantiser_scale_code           = quantiser_scale_code;
     slice_param->intra_slice_flag               = intra_slice_flag;
     return 0;
 }
 

 AVHWAccel ff_mpeg2_vaapi_hwaccel = {

     .name           = "mpeg2_vaapi",

     .type           = AVMEDIA_TYPE_VIDEO,

     .id             = AV_CODEC_ID_MPEG2VIDEO,

     .pix_fmt        = AV_PIX_FMT_VAAPI,

     .start_frame    = vaapi_mpeg2_start_frame,

     .end_frame      = ff_vaapi_mpeg_end_frame,

     .decode_slice   = vaapi_mpeg2_decode_slice,

     .init           = ff_vaapi_context_init,
     .uninit         = ff_vaapi_context_fini,
     .priv_data_size = sizeof(FFVAContext),

 };