git.sesse.net Git - ffmpeg/blob - libavcodec/vaapi_h264.c

   1 /*
   2  * H.264 HW decode acceleration through VA API
   3  *
   4  * Copyright (C) 2008-2009 Splitted-Desktop Systems
   5  *
   6  * This file is part of FFmpeg.
   7  *
   8  * FFmpeg is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * FFmpeg is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with FFmpeg; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 #include "vaapi_internal.h"
  24 #include "h264.h"
  25
  26 /** @file
  27  *  This file implements the glue code between FFmpeg's and VA API's
  28  *  structures for H.264 decoding.
  29  */
  30
  31 /**
  32  * Initializes an empty VA API picture.
  33  *
  34  * VA API requires a fixed-size reference picture array.
  35  */
  36 static void init_vaapi_pic(VAPictureH264 *va_pic)
  37 {
  38     va_pic->picture_id          = VA_INVALID_ID;
  39     va_pic->flags               = VA_PICTURE_H264_INVALID;
  40     va_pic->TopFieldOrderCnt    = 0;
  41     va_pic->BottomFieldOrderCnt = 0;
  42 }
  43
  44 /**
  45  * Translates an FFmpeg Picture into its VA API form.
  46  *
  47  * @param[out] va_pic          A pointer to VA API's own picture struct
  48  * @param[in]  pic             A pointer to the FFmpeg picture struct to convert
  49  * @param[in]  pic_structure   The picture field type (as defined in mpegvideo.h),
  50  *                             supersedes pic's field type if nonzero.
  51  */
  52 static void fill_vaapi_pic(VAPictureH264 *va_pic,
  53                            Picture       *pic,
  54                            int            pic_structure)
  55 {
  56     if (pic_structure == 0)
  57         pic_structure = pic->reference;
  58
  59     va_pic->picture_id = ff_vaapi_get_surface_id(pic);
  60     va_pic->frame_idx  = pic->long_ref ? pic->pic_id : pic->frame_num;
  61
  62     va_pic->flags      = 0;
  63     if (pic_structure != PICT_FRAME)
  64         va_pic->flags |= (pic_structure & PICT_TOP_FIELD) ? VA_PICTURE_H264_TOP_FIELD : VA_PICTURE_H264_BOTTOM_FIELD;
  65     if (pic->reference)
  66         va_pic->flags |= pic->long_ref ? VA_PICTURE_H264_LONG_TERM_REFERENCE : VA_PICTURE_H264_SHORT_TERM_REFERENCE;
  67
  68     va_pic->TopFieldOrderCnt = 0;
  69     if (pic->field_poc[0] != INT_MAX)
  70         va_pic->TopFieldOrderCnt = pic->field_poc[0];
  71
  72     va_pic->BottomFieldOrderCnt = 0;
  73     if (pic->field_poc[1] != INT_MAX)
  74         va_pic->BottomFieldOrderCnt = pic->field_poc[1];
  75 }
  76
  77 /** Decoded Picture Buffer (DPB). */
  78 typedef struct DPB {
  79     int            size;        ///< Current number of reference frames in the DPB
  80     int            max_size;    ///< Max number of reference frames. This is FF_ARRAY_ELEMS(VAPictureParameterBufferH264.ReferenceFrames)
  81     VAPictureH264 *va_pics;     ///< Pointer to VAPictureParameterBufferH264.ReferenceFrames array
  82 } DPB;
  83
  84 /**
  85  * Appends picture to the decoded picture buffer, in a VA API form that
  86  * merges the second field picture attributes with the first, if
  87  * available.  The decoded picture buffer's size must be large enough
  88  * to receive the new VA API picture object.
  89  */
  90 static int dpb_add(DPB *dpb, Picture *pic)
  91 {
  92     int i;
  93
  94     if (dpb->size >= dpb->max_size)
  95         return -1;
  96
  97     for (i = 0; i < dpb->size; i++) {
  98         VAPictureH264 * const va_pic = &dpb->va_pics[i];
  99         if (va_pic->picture_id == ff_vaapi_get_surface_id(pic)) {
 100             VAPictureH264 temp_va_pic;
 101             fill_vaapi_pic(&temp_va_pic, pic, 0);
 102
 103             if ((temp_va_pic.flags ^ va_pic->flags) & (VA_PICTURE_H264_TOP_FIELD | VA_PICTURE_H264_BOTTOM_FIELD)) {
 104                 va_pic->flags |= temp_va_pic.flags & (VA_PICTURE_H264_TOP_FIELD | VA_PICTURE_H264_BOTTOM_FIELD);
 105                 /* Merge second field */
 106                 if (temp_va_pic.flags & VA_PICTURE_H264_TOP_FIELD) {
 107                     va_pic->TopFieldOrderCnt    = temp_va_pic.TopFieldOrderCnt;
 108                 } else {
 109                     va_pic->BottomFieldOrderCnt = temp_va_pic.BottomFieldOrderCnt;
 110                 }
 111             }
 112             return 0;
 113         }
 114     }
 115
 116     fill_vaapi_pic(&dpb->va_pics[dpb->size++], pic, 0);
 117     return 0;
 118 }
 119
 120 /** Fills in VA API reference frames array. */
 121 static int fill_vaapi_ReferenceFrames(VAPictureParameterBufferH264 *pic_param,
 122                                       H264Context                  *h)
 123 {
 124     DPB dpb;
 125     int i;
 126
 127     dpb.size     = 0;
 128     dpb.max_size = FF_ARRAY_ELEMS(pic_param->ReferenceFrames);
 129     dpb.va_pics  = pic_param->ReferenceFrames;
 130     for (i = 0; i < dpb.max_size; i++)
 131         init_vaapi_pic(&dpb.va_pics[i]);
 132
 133     for (i = 0; i < h->short_ref_count; i++) {
 134         Picture * const pic = h->short_ref[i];
 135         if (pic && pic->reference && dpb_add(&dpb, pic) < 0)
 136             return -1;
 137     }
 138
 139     for (i = 0; i < 16; i++) {
 140         Picture * const pic = h->long_ref[i];
 141         if (pic && pic->reference && dpb_add(&dpb, pic) < 0)
 142             return -1;
 143     }
 144     return 0;
 145 }
 146
 147 /**
 148  * Fills in VA API reference picture lists from the FFmpeg reference
 149  * picture list.
 150  *
 151  * @param[out] RefPicList  VA API internal reference picture list
 152  * @param[in]  ref_list    A pointer to the FFmpeg reference list
 153  * @param[in]  ref_count   The number of reference pictures in ref_list
 154  */
 155 static void fill_vaapi_RefPicList(VAPictureH264 RefPicList[32],
 156                                   Picture      *ref_list,
 157                                   unsigned int  ref_count)
 158 {
 159     unsigned int i, n = 0;
 160     for (i = 0; i < ref_count; i++)
 161         if (ref_list[i].reference)
 162             fill_vaapi_pic(&RefPicList[n++], &ref_list[i], 0);
 163
 164     for (; n < 32; n++)
 165         init_vaapi_pic(&RefPicList[n]);
 166 }
 167
 168 /**
 169  * Fills in prediction weight table.
 170  *
 171  * VA API requires a plain prediction weight table as it does not infer
 172  * any value.
 173  *
 174  * @param[in]  h                   A pointer to the current H.264 context
 175  * @param[in]  list                The reference frame list index to use
 176  * @param[out] luma_weight_flag    VA API plain luma weight flag
 177  * @param[out] luma_weight         VA API plain luma weight table
 178  * @param[out] luma_offset         VA API plain luma offset table
 179  * @param[out] chroma_weight_flag  VA API plain chroma weight flag
 180  * @param[out] chroma_weight       VA API plain chroma weight table
 181  * @param[out] chroma_offset       VA API plain chroma offset table
 182  */
 183 static void fill_vaapi_plain_pred_weight_table(H264Context   *h,
 184                                                int            list,
 185                                                unsigned char *luma_weight_flag,
 186                                                short          luma_weight[32],
 187                                                short          luma_offset[32],
 188                                                unsigned char *chroma_weight_flag,
 189                                                short          chroma_weight[32][2],
 190                                                short          chroma_offset[32][2])
 191 {
 192     unsigned int i, j;
 193
 194     *luma_weight_flag    = h->luma_weight_flag[list];
 195     *chroma_weight_flag  = h->chroma_weight_flag[list];
 196
 197     for (i = 0; i < h->ref_count[list]; i++) {
 198         /* VA API also wants the inferred (default) values, not
 199            only what is available in the bitstream (7.4.3.2). */
 200         if (h->luma_weight_flag[list]) {
 201             luma_weight[i] = h->luma_weight[i][list][0];
 202             luma_offset[i] = h->luma_weight[i][list][1];
 203         } else {
 204             luma_weight[i] = 1 << h->luma_log2_weight_denom;
 205             luma_offset[i] = 0;
 206         }
 207         for (j = 0; j < 2; j++) {
 208             if (h->chroma_weight_flag[list]) {
 209                 chroma_weight[i][j] = h->chroma_weight[i][list][j][0];
 210                 chroma_offset[i][j] = h->chroma_weight[i][list][j][1];
 211             } else {
 212                 chroma_weight[i][j] = 1 << h->chroma_log2_weight_denom;
 213                 chroma_offset[i][j] = 0;
 214             }
 215         }
 216     }
 217 }
 218
 219 /** Initializes and starts decoding a frame with VA API. */
 220 static int start_frame(AVCodecContext          *avctx,
 221                        av_unused const uint8_t *buffer,
 222                        av_unused uint32_t       size)
 223 {
 224     H264Context * const h = avctx->priv_data;
 225     MpegEncContext * const s = &h->s;
 226     struct vaapi_context * const vactx = avctx->hwaccel_context;
 227     VAPictureParameterBufferH264 *pic_param;
 228     VAIQMatrixBufferH264 *iq_matrix;
 229
 230     dprintf(avctx, "start_frame()\n");
 231
 232     vactx->slice_param_size = sizeof(VASliceParameterBufferH264);
 233
 234     /* Fill in VAPictureParameterBufferH264. */
 235     pic_param = ff_vaapi_alloc_pic_param(vactx, sizeof(VAPictureParameterBufferH264));
 236     if (!pic_param)
 237         return -1;
 238     fill_vaapi_pic(&pic_param->CurrPic, s->current_picture_ptr, s->picture_structure);
 239     if (fill_vaapi_ReferenceFrames(pic_param, h) < 0)
 240         return -1;
 241     pic_param->picture_width_in_mbs_minus1                      = s->mb_width - 1;
 242     pic_param->picture_height_in_mbs_minus1                     = s->mb_height - 1;
 243     pic_param->bit_depth_luma_minus8                            = h->sps.bit_depth_luma - 8;
 244     pic_param->bit_depth_chroma_minus8                          = h->sps.bit_depth_chroma - 8;
 245     pic_param->num_ref_frames                                   = h->sps.ref_frame_count;
 246     pic_param->seq_fields.value                                 = 0; /* reset all bits */
 247     pic_param->seq_fields.bits.chroma_format_idc                = h->sps.chroma_format_idc;
 248     pic_param->seq_fields.bits.residual_colour_transform_flag   = h->sps.residual_color_transform_flag; /* XXX: only for 4:4:4 high profile? */
 249     pic_param->seq_fields.bits.gaps_in_frame_num_value_allowed_flag = h->sps.gaps_in_frame_num_allowed_flag;
 250     pic_param->seq_fields.bits.frame_mbs_only_flag              = h->sps.frame_mbs_only_flag;
 251     pic_param->seq_fields.bits.mb_adaptive_frame_field_flag     = h->sps.mb_aff;
 252     pic_param->seq_fields.bits.direct_8x8_inference_flag        = h->sps.direct_8x8_inference_flag;
 253     pic_param->seq_fields.bits.MinLumaBiPredSize8x8             = h->sps.level_idc >= 31; /* A.3.3.2 */
 254     pic_param->seq_fields.bits.log2_max_frame_num_minus4        = h->sps.log2_max_frame_num - 4;
 255     pic_param->seq_fields.bits.pic_order_cnt_type               = h->sps.poc_type;
 256     pic_param->seq_fields.bits.log2_max_pic_order_cnt_lsb_minus4 = h->sps.log2_max_poc_lsb - 4;
 257     pic_param->seq_fields.bits.delta_pic_order_always_zero_flag = h->sps.delta_pic_order_always_zero_flag;
 258     pic_param->num_slice_groups_minus1                          = h->pps.slice_group_count - 1;
 259     pic_param->slice_group_map_type                             = h->pps.mb_slice_group_map_type;
 260     pic_param->slice_group_change_rate_minus1                   = 0; /* XXX: unimplemented in FFmpeg */
 261     pic_param->pic_init_qp_minus26                              = h->pps.init_qp - 26;
 262     pic_param->pic_init_qs_minus26                              = h->pps.init_qs - 26;
 263     pic_param->chroma_qp_index_offset                           = h->pps.chroma_qp_index_offset[0];
 264     pic_param->second_chroma_qp_index_offset                    = h->pps.chroma_qp_index_offset[1];
 265     pic_param->pic_fields.value                                 = 0; /* reset all bits */
 266     pic_param->pic_fields.bits.entropy_coding_mode_flag         = h->pps.cabac;
 267     pic_param->pic_fields.bits.weighted_pred_flag               = h->pps.weighted_pred;
 268     pic_param->pic_fields.bits.weighted_bipred_idc              = h->pps.weighted_bipred_idc;
 269     pic_param->pic_fields.bits.transform_8x8_mode_flag          = h->pps.transform_8x8_mode;
 270     pic_param->pic_fields.bits.field_pic_flag                   = s->picture_structure != PICT_FRAME;
 271     pic_param->pic_fields.bits.constrained_intra_pred_flag      = h->pps.constrained_intra_pred;
 272     pic_param->pic_fields.bits.pic_order_present_flag           = h->pps.pic_order_present;
 273     pic_param->pic_fields.bits.deblocking_filter_control_present_flag = h->pps.deblocking_filter_parameters_present;
 274     pic_param->pic_fields.bits.redundant_pic_cnt_present_flag   = h->pps.redundant_pic_cnt_present;
 275     pic_param->pic_fields.bits.reference_pic_flag               = h->nal_ref_idc != 0;
 276     pic_param->frame_num                                        = h->frame_num;
 277
 278     /* Fill in VAIQMatrixBufferH264. */
 279     iq_matrix = ff_vaapi_alloc_iq_matrix(vactx, sizeof(VAIQMatrixBufferH264));
 280     if (!iq_matrix)
 281         return -1;
 282     memcpy(iq_matrix->ScalingList4x4, h->pps.scaling_matrix4, sizeof(iq_matrix->ScalingList4x4));
 283     memcpy(iq_matrix->ScalingList8x8, h->pps.scaling_matrix8, sizeof(iq_matrix->ScalingList8x8));
 284     return 0;
 285 }
 286
 287 /** Ends a hardware decoding based frame. */
 288 static int end_frame(AVCodecContext *avctx)
 289 {
 290     H264Context * const h = avctx->priv_data;
 291
 292     dprintf(avctx, "end_frame()\n");
 293     return ff_vaapi_common_end_frame(&h->s);
 294 }
 295
 296 /** Decodes the given H.264 slice with VA API. */
 297 static int decode_slice(AVCodecContext *avctx,
 298                         const uint8_t  *buffer,
 299                         uint32_t        size)
 300 {
 301     H264Context * const h = avctx->priv_data;
 302     MpegEncContext * const s = &h->s;
 303     VASliceParameterBufferH264 *slice_param;
 304
 305     dprintf(avctx, "decode_slice(): buffer %p, size %d\n", buffer, size);
 306
 307     /* Fill in VASliceParameterBufferH264. */
 308     slice_param = (VASliceParameterBufferH264 *)ff_vaapi_alloc_slice(avctx->hwaccel_context, buffer, size);
 309     if (!slice_param)
 310         return -1;
 311     slice_param->slice_data_bit_offset          = get_bits_count(&h->s.gb) + 8; /* bit buffer started beyond nal_unit_type */
 312     slice_param->first_mb_in_slice              = (s->mb_y >> FIELD_OR_MBAFF_PICTURE) * s->mb_width + s->mb_x;
 313     slice_param->slice_type                     = ff_h264_get_slice_type(h);
 314     slice_param->direct_spatial_mv_pred_flag    = h->slice_type == FF_B_TYPE ? h->direct_spatial_mv_pred : 0;
 315     slice_param->num_ref_idx_l0_active_minus1   = h->list_count > 0 ? h->ref_count[0] - 1 : 0;
 316     slice_param->num_ref_idx_l1_active_minus1   = h->list_count > 1 ? h->ref_count[1] - 1 : 0;
 317     slice_param->cabac_init_idc                 = h->cabac_init_idc;
 318     slice_param->slice_qp_delta                 = s->qscale - h->pps.init_qp;
 319     slice_param->disable_deblocking_filter_idc  = h->deblocking_filter < 2 ? !h->deblocking_filter : h->deblocking_filter;
 320     slice_param->slice_alpha_c0_offset_div2     = h->slice_alpha_c0_offset / 2 - 26;
 321     slice_param->slice_beta_offset_div2         = h->slice_beta_offset     / 2 - 26;
 322     slice_param->luma_log2_weight_denom         = h->luma_log2_weight_denom;
 323     slice_param->chroma_log2_weight_denom       = h->chroma_log2_weight_denom;
 324
 325     fill_vaapi_RefPicList(slice_param->RefPicList0, h->ref_list[0], h->list_count > 0 ? h->ref_count[0] : 0);
 326     fill_vaapi_RefPicList(slice_param->RefPicList1, h->ref_list[1], h->list_count > 1 ? h->ref_count[1] : 0);
 327
 328     fill_vaapi_plain_pred_weight_table(h, 0,
 329                                        &slice_param->luma_weight_l0_flag,   slice_param->luma_weight_l0,   slice_param->luma_offset_l0,
 330                                        &slice_param->chroma_weight_l0_flag, slice_param->chroma_weight_l0, slice_param->chroma_offset_l0);
 331     fill_vaapi_plain_pred_weight_table(h, 1,
 332                                        &slice_param->luma_weight_l1_flag,   slice_param->luma_weight_l1,   slice_param->luma_offset_l1,
 333                                        &slice_param->chroma_weight_l1_flag, slice_param->chroma_weight_l1, slice_param->chroma_offset_l1);
 334     return 0;
 335 }
 336
 337 AVHWAccel h264_vaapi_hwaccel = {
 338     .name           = "h264_vaapi",
 339     .type           = AVMEDIA_TYPE_VIDEO,
 340     .id             = CODEC_ID_H264,
 341     .pix_fmt        = PIX_FMT_VAAPI_VLD,
 342     .capabilities   = 0,
 343     .start_frame    = start_frame,
 344     .end_frame      = end_frame,
 345     .decode_slice   = decode_slice,
 346     .priv_data_size = 0,
 347 };