PeerStreamer

/*

 * 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 "vaapi_internal.h"

#include "dsputil.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;

    struct vaapi_context * const vactx = avctx->hwaccel_context;

    VAPictureParameterBufferMPEG2 *pic_param;

    VAIQMatrixBufferMPEG2 *iq_matrix;

    int i;

    av_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);

        // fall-through

    case AV_PICTURE_TYPE_P:

        pic_param->forward_reference_picture = ff_vaapi_get_surface_id(&s->last_picture);

        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->dsp.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_end_frame(AVCodecContext *avctx)

{

    return ff_vaapi_common_end_frame(avctx->priv_data);

}

static int vaapi_mpeg2_decode_slice(AVCodecContext *avctx, const uint8_t *buffer, uint32_t size)

{

    MpegEncContext * const s = avctx->priv_data;

    VASliceParameterBufferMPEG2 *slice_param;

    GetBitContext gb;

    uint32_t start_code, quantiser_scale_code, intra_slice_flag, macroblock_offset;

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

    /* Determine macroblock_offset */

    init_get_bits(&gb, buffer, 8 * size);

    start_code = get_bits(&gb, 32);

    assert((start_code & 0xffffff00) == 0x00000100);

    quantiser_scale_code = get_bits(&gb, 5);

    intra_slice_flag = get_bits1(&gb);

    if (intra_slice_flag) {

        skip_bits(&gb, 8);

        while (get_bits1(&gb) != 0)

            skip_bits(&gb, 8);

    }

    macroblock_offset = get_bits_count(&gb);

    /* Fill in VASliceParameterBufferMPEG2 */

    slice_param = (VASliceParameterBufferMPEG2 *)ff_vaapi_alloc_slice(avctx->hwaccel_context, 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;

    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             = CODEC_ID_MPEG2VIDEO,

    .pix_fmt        = PIX_FMT_VAAPI_VLD,

    .capabilities   = 0,

    .start_frame    = vaapi_mpeg2_start_frame,

    .end_frame      = vaapi_mpeg2_end_frame,

    .decode_slice   = vaapi_mpeg2_decode_slice,

    .priv_data_size = 0,

};