libavcodec/dxva2_mpeg2.c - play-games/ffmpeg - Git at Google


            
            /*

            
             * 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 "config_components.h"


            #include "libavutil/log.h"


            #include "dxva2_internal.h"

            
            #include "hwaccel_internal.h"

            
            #include "mpegutils.h"

            
            #include "mpegvideodec.h"


            #define MAX_SLICES 1024

            
            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;

            
            };


            void ff_dxva2_mpeg2_fill_picture_parameters(AVCodecContext *avctx,

            
                                                AVDXVAContext *ctx,

            
                                                DXVA_PictureParameters *pp)

            
            {

            
                const struct MpegEncContext *s = avctx->priv_data;

            
                const Picture *current_picture = s->current_picture_ptr;

            
                int is_field = s->picture_structure != PICT_FRAME;


                memset(pp, 0, sizeof(*pp));

            
                pp->wDeblockedPictureIndex       = 0;

            
                if (s->pict_type != AV_PICTURE_TYPE_I)

            
                    pp->wForwardRefPictureIndex  = ff_dxva2_get_surface_index(avctx, ctx, s->last_picture.f, 0);

            
                else

            
                    pp->wForwardRefPictureIndex  = 0xffff;

            
                if (s->pict_type == AV_PICTURE_TYPE_B)

            
                    pp->wBackwardRefPictureIndex = ff_dxva2_get_surface_index(avctx, ctx, s->next_picture.f, 0);

            
                else

            
                    pp->wBackwardRefPictureIndex = 0xffff;

            
                pp->wDecodedPictureIndex         = ff_dxva2_get_surface_index(avctx, ctx, current_picture->f, 1);

            
                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;

            
            }


            void ff_dxva2_mpeg2_fill_quantization_matrices(AVCodecContext *avctx,

            
                                                   AVDXVAContext *ctx,

            
                                                   DXVA_QmatrixData *qm)

            
            {

            
                const struct MpegEncContext *s = avctx->priv_data;

            
                int i;

            
                for (i = 0; i < 4; i++)

            
                    qm->bNewQmatrix[i] = 1;

            
                for (i = 0; i < 64; i++) {

            
                    int n = s->idsp.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];

            
                }

            
            }


            void ff_dxva2_mpeg2_fill_slice(AVCodecContext *avctx,

            
                                   DXVA_SliceInfo *slice,

            
                                   unsigned position,

            
                                   const uint8_t *buffer, unsigned size)

            
            {

            
                const struct MpegEncContext *s = avctx->priv_data;

            
                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);

            
                skip_1stop_8data_bits(&gb);


                slice->wMBbitOffset        = 4 * 8 + get_bits_count(&gb);

            
            }

            
            static int commit_bitstream_and_slice_buffer(AVCodecContext *avctx,

            
                                                         DECODER_BUFFER_DESC *bs,

            
                                                         DECODER_BUFFER_DESC *sc)

            
            {

            
                const struct MpegEncContext *s = avctx->priv_data;

            
                AVDXVAContext *ctx = DXVA_CONTEXT(avctx);

            
                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);

            
                void     *dxva_data_ptr;

            
                uint8_t  *dxva_data, *current, *end;

            
                unsigned dxva_size;

            
                unsigned i;

            
                unsigned type;


            #if CONFIG_D3D11VA

            
                if (ff_dxva2_is_d3d11(avctx)) {

            
                    type = D3D11_VIDEO_DECODER_BUFFER_BITSTREAM;

            
                    if (FAILED(ID3D11VideoContext_GetDecoderBuffer(D3D11VA_CONTEXT(ctx)->video_context,

            
                                                                   D3D11VA_CONTEXT(ctx)->decoder,

            
                                                                   type,

            
                                                                   &dxva_size, &dxva_data_ptr)))

            
                        return -1;

            
                }

            
            #endif

            
            #if CONFIG_DXVA2

            
                if (avctx->pix_fmt == AV_PIX_FMT_DXVA2_VLD) {

            
                    type = DXVA2_BitStreamDateBufferType;

            
                    if (FAILED(IDirectXVideoDecoder_GetBuffer(DXVA2_CONTEXT(ctx)->decoder,

            
                                                              type,

            
                                                              &dxva_data_ptr, &dxva_size)))

            
                        return -1;

            
                }

            
            #endif


                dxva_data = dxva_data_ptr;

            
                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 CONFIG_D3D11VA

            
                if (ff_dxva2_is_d3d11(avctx))

            
                    if (FAILED(ID3D11VideoContext_ReleaseDecoderBuffer(D3D11VA_CONTEXT(ctx)->video_context, D3D11VA_CONTEXT(ctx)->decoder, type)))

            
                        return -1;

            
            #endif

            
            #if CONFIG_DXVA2

            
                if (avctx->pix_fmt == AV_PIX_FMT_DXVA2_VLD)

            
                    if (FAILED(IDirectXVideoDecoder_ReleaseBuffer(DXVA2_CONTEXT(ctx)->decoder, type)))

            
                        return -1;

            
            #endif

            
                if (i < ctx_pic->slice_count)

            
                    return -1;


            #if CONFIG_D3D11VA

            
                if (ff_dxva2_is_d3d11(avctx)) {

            
                    D3D11_VIDEO_DECODER_BUFFER_DESC *dsc11 = bs;

            
                    memset(dsc11, 0, sizeof(*dsc11));

            
                    dsc11->BufferType           = type;

            
                    dsc11->DataSize             = current - dxva_data;

            
                    dsc11->NumMBsInBuffer       = mb_count;


                    type = D3D11_VIDEO_DECODER_BUFFER_SLICE_CONTROL;

            
                }

            
            #endif

            
            #if CONFIG_DXVA2

            
                if (avctx->pix_fmt == AV_PIX_FMT_DXVA2_VLD) {

            
                    DXVA2_DecodeBufferDesc *dsc2 = bs;

            
                    memset(dsc2, 0, sizeof(*dsc2));

            
                    dsc2->CompressedBufferType = type;

            
                    dsc2->DataSize             = current - dxva_data;

            
                    dsc2->NumMBsInBuffer       = mb_count;


                    type = DXVA2_SliceControlBufferType;

            
                }

            
            #endif


                return ff_dxva2_commit_buffer(avctx, ctx, sc,

            
                                              type,

            
                                              ctx_pic->slice,

            
                                              ctx_pic->slice_count * sizeof(*ctx_pic->slice),

            
                                              mb_count);

            
            }


            static int dxva2_mpeg2_start_frame(AVCodecContext *avctx,

            
                                               av_unused const uint8_t *buffer,

            
                                               av_unused uint32_t size)

            
            {

            
                const struct MpegEncContext *s = avctx->priv_data;

            
                AVDXVAContext *ctx = DXVA_CONTEXT(avctx);

            
                struct dxva2_picture_context *ctx_pic =

            
                    s->current_picture_ptr->hwaccel_picture_private;


                if (!DXVA_CONTEXT_VALID(avctx, ctx))

            
                    return -1;

            
                av_assert0(ctx_pic);


                ff_dxva2_mpeg2_fill_picture_parameters(avctx, ctx, &ctx_pic->pp);

            
                ff_dxva2_mpeg2_fill_quantization_matrices(avctx, ctx, &ctx_pic->qm);


                ctx_pic->slice_count    = 0;

            
                ctx_pic->bitstream_size = 0;

            
                ctx_pic->bitstream      = NULL;

            
                return 0;

            
            }


            static int dxva2_mpeg2_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) {

            
                    avpriv_request_sample(avctx, "%d slices in dxva2",

            
                                          ctx_pic->slice_count);

            
                    return -1;

            
                }

            
                if (!ctx_pic->bitstream)

            
                    ctx_pic->bitstream = buffer;

            
                ctx_pic->bitstream_size += size;


                position = buffer - ctx_pic->bitstream;

            
                ff_dxva2_mpeg2_fill_slice(avctx, &ctx_pic->slice[ctx_pic->slice_count++], position,

            
                           buffer, size);

            
                return 0;

            
            }


            static int dxva2_mpeg2_end_frame(AVCodecContext *avctx)

            
            {

            
                struct MpegEncContext *s = avctx->priv_data;

            
                struct dxva2_picture_context *ctx_pic =

            
                    s->current_picture_ptr->hwaccel_picture_private;

            
                int ret;


                if (ctx_pic->slice_count <= 0 || ctx_pic->bitstream_size <= 0)

            
                    return -1;

            
                ret = ff_dxva2_common_end_frame(avctx, s->current_picture_ptr->f,

            
                                                &ctx_pic->pp, sizeof(ctx_pic->pp),

            
                                                &ctx_pic->qm, sizeof(ctx_pic->qm),

            
                                                commit_bitstream_and_slice_buffer);

            
                if (!ret)

            
                    ff_mpeg_draw_horiz_band(s, 0, avctx->height);

            
                return ret;

            
            }


            #if CONFIG_MPEG2_DXVA2_HWACCEL

            
            const FFHWAccel ff_mpeg2_dxva2_hwaccel = {

            
                .p.name         = "mpeg2_dxva2",

            
                .p.type         = AVMEDIA_TYPE_VIDEO,

            
                .p.id           = AV_CODEC_ID_MPEG2VIDEO,

            
                .p.pix_fmt      = AV_PIX_FMT_DXVA2_VLD,

            
                .init           = ff_dxva2_decode_init,

            
                .uninit         = ff_dxva2_decode_uninit,

            
                .start_frame    = dxva2_mpeg2_start_frame,

            
                .decode_slice   = dxva2_mpeg2_decode_slice,

            
                .end_frame      = dxva2_mpeg2_end_frame,

            
                .frame_params   = ff_dxva2_common_frame_params,

            
                .frame_priv_data_size = sizeof(struct dxva2_picture_context),

            
                .priv_data_size = sizeof(FFDXVASharedContext),

            
            };

            
            #endif


            #if CONFIG_MPEG2_D3D11VA_HWACCEL

            
            const FFHWAccel ff_mpeg2_d3d11va_hwaccel = {

            
                .p.name         = "mpeg2_d3d11va",

            
                .p.type         = AVMEDIA_TYPE_VIDEO,

            
                .p.id           = AV_CODEC_ID_MPEG2VIDEO,

            
                .p.pix_fmt      = AV_PIX_FMT_D3D11VA_VLD,

            
                .init           = ff_dxva2_decode_init,

            
                .uninit         = ff_dxva2_decode_uninit,

            
                .start_frame    = dxva2_mpeg2_start_frame,

            
                .decode_slice   = dxva2_mpeg2_decode_slice,

            
                .end_frame      = dxva2_mpeg2_end_frame,

            
                .frame_params   = ff_dxva2_common_frame_params,

            
                .frame_priv_data_size = sizeof(struct dxva2_picture_context),

            
                .priv_data_size = sizeof(FFDXVASharedContext),

            
            };

            
            #endif


            #if CONFIG_MPEG2_D3D11VA2_HWACCEL

            
            const FFHWAccel ff_mpeg2_d3d11va2_hwaccel = {

            
                .p.name         = "mpeg2_d3d11va2",

            
                .p.type         = AVMEDIA_TYPE_VIDEO,

            
                .p.id           = AV_CODEC_ID_MPEG2VIDEO,

            
                .p.pix_fmt      = AV_PIX_FMT_D3D11,

            
                .init           = ff_dxva2_decode_init,

            
                .uninit         = ff_dxva2_decode_uninit,

            
                .start_frame    = dxva2_mpeg2_start_frame,

            
                .decode_slice   = dxva2_mpeg2_decode_slice,

            
                .end_frame      = dxva2_mpeg2_end_frame,

            
                .frame_params   = ff_dxva2_common_frame_params,

            
                .frame_priv_data_size = sizeof(struct dxva2_picture_context),

            
                .priv_data_size = sizeof(FFDXVASharedContext),

            
            };

            
            #endif
	/*
	* 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 "config_components.h"

	#include "libavutil/log.h"

	#include "dxva2_internal.h"
	#include "hwaccel_internal.h"
	#include "mpegutils.h"
	#include "mpegvideodec.h"

	#define MAX_SLICES 1024
	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;
	};

	void ff_dxva2_mpeg2_fill_picture_parameters(AVCodecContext *avctx,
	AVDXVAContext *ctx,
	DXVA_PictureParameters *pp)
	{
	const struct MpegEncContext *s = avctx->priv_data;
	const Picture *current_picture = s->current_picture_ptr;
	int is_field = s->picture_structure != PICT_FRAME;

	memset(pp, 0, sizeof(*pp));
	pp->wDeblockedPictureIndex = 0;
	if (s->pict_type != AV_PICTURE_TYPE_I)
	pp->wForwardRefPictureIndex = ff_dxva2_get_surface_index(avctx, ctx, s->last_picture.f, 0);
	else
	pp->wForwardRefPictureIndex = 0xffff;
	if (s->pict_type == AV_PICTURE_TYPE_B)
	pp->wBackwardRefPictureIndex = ff_dxva2_get_surface_index(avctx, ctx, s->next_picture.f, 0);
	else
	pp->wBackwardRefPictureIndex = 0xffff;
	pp->wDecodedPictureIndex = ff_dxva2_get_surface_index(avctx, ctx, current_picture->f, 1);
	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;
	}

	void ff_dxva2_mpeg2_fill_quantization_matrices(AVCodecContext *avctx,
	AVDXVAContext *ctx,
	DXVA_QmatrixData *qm)
	{
	const struct MpegEncContext *s = avctx->priv_data;
	int i;
	for (i = 0; i < 4; i++)
	qm->bNewQmatrix[i] = 1;
	for (i = 0; i < 64; i++) {
	int n = s->idsp.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];
	}
	}

	void ff_dxva2_mpeg2_fill_slice(AVCodecContext *avctx,
	DXVA_SliceInfo *slice,
	unsigned position,
	const uint8_t *buffer, unsigned size)
	{
	const struct MpegEncContext *s = avctx->priv_data;
	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);
	skip_1stop_8data_bits(&gb);

	slice->wMBbitOffset = 4 * 8 + get_bits_count(&gb);
	}
	static int commit_bitstream_and_slice_buffer(AVCodecContext *avctx,
	DECODER_BUFFER_DESC *bs,
	DECODER_BUFFER_DESC *sc)
	{
	const struct MpegEncContext *s = avctx->priv_data;
	AVDXVAContext *ctx = DXVA_CONTEXT(avctx);
	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);
	void *dxva_data_ptr;
	uint8_t dxva_data, current, *end;
	unsigned dxva_size;
	unsigned i;
	unsigned type;

	#if CONFIG_D3D11VA
	if (ff_dxva2_is_d3d11(avctx)) {
	type = D3D11_VIDEO_DECODER_BUFFER_BITSTREAM;
	if (FAILED(ID3D11VideoContext_GetDecoderBuffer(D3D11VA_CONTEXT(ctx)->video_context,
	D3D11VA_CONTEXT(ctx)->decoder,
	type,
	&dxva_size, &dxva_data_ptr)))
	return -1;
	}
	#endif
	#if CONFIG_DXVA2
	if (avctx->pix_fmt == AV_PIX_FMT_DXVA2_VLD) {
	type = DXVA2_BitStreamDateBufferType;
	if (FAILED(IDirectXVideoDecoder_GetBuffer(DXVA2_CONTEXT(ctx)->decoder,
	type,
	&dxva_data_ptr, &dxva_size)))
	return -1;
	}
	#endif

	dxva_data = dxva_data_ptr;
	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 CONFIG_D3D11VA
	if (ff_dxva2_is_d3d11(avctx))
	if (FAILED(ID3D11VideoContext_ReleaseDecoderBuffer(D3D11VA_CONTEXT(ctx)->video_context, D3D11VA_CONTEXT(ctx)->decoder, type)))
	return -1;
	#endif
	#if CONFIG_DXVA2
	if (avctx->pix_fmt == AV_PIX_FMT_DXVA2_VLD)
	if (FAILED(IDirectXVideoDecoder_ReleaseBuffer(DXVA2_CONTEXT(ctx)->decoder, type)))
	return -1;
	#endif
	if (i < ctx_pic->slice_count)
	return -1;

	#if CONFIG_D3D11VA
	if (ff_dxva2_is_d3d11(avctx)) {
	D3D11_VIDEO_DECODER_BUFFER_DESC *dsc11 = bs;
	memset(dsc11, 0, sizeof(*dsc11));
	dsc11->BufferType = type;
	dsc11->DataSize = current - dxva_data;
	dsc11->NumMBsInBuffer = mb_count;

	type = D3D11_VIDEO_DECODER_BUFFER_SLICE_CONTROL;
	}
	#endif
	#if CONFIG_DXVA2
	if (avctx->pix_fmt == AV_PIX_FMT_DXVA2_VLD) {
	DXVA2_DecodeBufferDesc *dsc2 = bs;
	memset(dsc2, 0, sizeof(*dsc2));
	dsc2->CompressedBufferType = type;
	dsc2->DataSize = current - dxva_data;
	dsc2->NumMBsInBuffer = mb_count;

	type = DXVA2_SliceControlBufferType;
	}
	#endif

	return ff_dxva2_commit_buffer(avctx, ctx, sc,
	type,
	ctx_pic->slice,
	ctx_pic->slice_count * sizeof(*ctx_pic->slice),
	mb_count);
	}

	static int dxva2_mpeg2_start_frame(AVCodecContext *avctx,
	av_unused const uint8_t *buffer,
	av_unused uint32_t size)
	{
	const struct MpegEncContext *s = avctx->priv_data;
	AVDXVAContext *ctx = DXVA_CONTEXT(avctx);
	struct dxva2_picture_context *ctx_pic =
	s->current_picture_ptr->hwaccel_picture_private;

	if (!DXVA_CONTEXT_VALID(avctx, ctx))
	return -1;
	av_assert0(ctx_pic);

	ff_dxva2_mpeg2_fill_picture_parameters(avctx, ctx, &ctx_pic->pp);
	ff_dxva2_mpeg2_fill_quantization_matrices(avctx, ctx, &ctx_pic->qm);

	ctx_pic->slice_count = 0;
	ctx_pic->bitstream_size = 0;
	ctx_pic->bitstream = NULL;
	return 0;
	}

	static int dxva2_mpeg2_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) {
	avpriv_request_sample(avctx, "%d slices in dxva2",
	ctx_pic->slice_count);
	return -1;
	}
	if (!ctx_pic->bitstream)
	ctx_pic->bitstream = buffer;
	ctx_pic->bitstream_size += size;

	position = buffer - ctx_pic->bitstream;
	ff_dxva2_mpeg2_fill_slice(avctx, &ctx_pic->slice[ctx_pic->slice_count++], position,
	buffer, size);
	return 0;
	}

	static int dxva2_mpeg2_end_frame(AVCodecContext *avctx)
	{
	struct MpegEncContext *s = avctx->priv_data;
	struct dxva2_picture_context *ctx_pic =
	s->current_picture_ptr->hwaccel_picture_private;
	int ret;

	if (ctx_pic->slice_count <= 0 \|\| ctx_pic->bitstream_size <= 0)
	return -1;
	ret = ff_dxva2_common_end_frame(avctx, s->current_picture_ptr->f,
	&ctx_pic->pp, sizeof(ctx_pic->pp),
	&ctx_pic->qm, sizeof(ctx_pic->qm),
	commit_bitstream_and_slice_buffer);
	if (!ret)
	ff_mpeg_draw_horiz_band(s, 0, avctx->height);
	return ret;
	}

	#if CONFIG_MPEG2_DXVA2_HWACCEL
	const FFHWAccel ff_mpeg2_dxva2_hwaccel = {
	.p.name = "mpeg2_dxva2",
	.p.type = AVMEDIA_TYPE_VIDEO,
	.p.id = AV_CODEC_ID_MPEG2VIDEO,
	.p.pix_fmt = AV_PIX_FMT_DXVA2_VLD,
	.init = ff_dxva2_decode_init,
	.uninit = ff_dxva2_decode_uninit,
	.start_frame = dxva2_mpeg2_start_frame,
	.decode_slice = dxva2_mpeg2_decode_slice,
	.end_frame = dxva2_mpeg2_end_frame,
	.frame_params = ff_dxva2_common_frame_params,
	.frame_priv_data_size = sizeof(struct dxva2_picture_context),
	.priv_data_size = sizeof(FFDXVASharedContext),
	};
	#endif

	#if CONFIG_MPEG2_D3D11VA_HWACCEL
	const FFHWAccel ff_mpeg2_d3d11va_hwaccel = {
	.p.name = "mpeg2_d3d11va",
	.p.type = AVMEDIA_TYPE_VIDEO,
	.p.id = AV_CODEC_ID_MPEG2VIDEO,
	.p.pix_fmt = AV_PIX_FMT_D3D11VA_VLD,
	.init = ff_dxva2_decode_init,
	.uninit = ff_dxva2_decode_uninit,
	.start_frame = dxva2_mpeg2_start_frame,
	.decode_slice = dxva2_mpeg2_decode_slice,
	.end_frame = dxva2_mpeg2_end_frame,
	.frame_params = ff_dxva2_common_frame_params,
	.frame_priv_data_size = sizeof(struct dxva2_picture_context),
	.priv_data_size = sizeof(FFDXVASharedContext),
	};
	#endif

	#if CONFIG_MPEG2_D3D11VA2_HWACCEL
	const FFHWAccel ff_mpeg2_d3d11va2_hwaccel = {
	.p.name = "mpeg2_d3d11va2",
	.p.type = AVMEDIA_TYPE_VIDEO,
	.p.id = AV_CODEC_ID_MPEG2VIDEO,
	.p.pix_fmt = AV_PIX_FMT_D3D11,
	.init = ff_dxva2_decode_init,
	.uninit = ff_dxva2_decode_uninit,
	.start_frame = dxva2_mpeg2_start_frame,
	.decode_slice = dxva2_mpeg2_decode_slice,
	.end_frame = dxva2_mpeg2_end_frame,
	.frame_params = ff_dxva2_common_frame_params,
	.frame_priv_data_size = sizeof(struct dxva2_picture_context),
	.priv_data_size = sizeof(FFDXVASharedContext),
	};
	#endif