src/gallium/drivers/nouveau/nouveau_vp3_video_vp.c

   1 /*
   2  * Copyright 2011-2013 Maarten Lankhorst
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice shall be included in
  12  * all copies or substantial portions of the Software.
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  17  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  18  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  19  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  20  * OTHER DEALINGS IN THE SOFTWARE.
  21  */
  22
  23 #include "nouveau_vp3_video.h"
  24
  25 struct mpeg12_picparm_vp {
  26    uint16_t width; // 00 in mb units
  27    uint16_t height; // 02 in mb units
  28
  29    uint32_t unk04; // 04 stride for Y?
  30    uint32_t unk08; // 08 stride for CbCr?
  31
  32    uint32_t ofs[6]; // 1c..20 ofs
  33    uint32_t bucket_size; // 24
  34    uint32_t inter_ring_data_size; // 28
  35    uint16_t unk2c; // 2c
  36    uint16_t alternate_scan; // 2e
  37    uint16_t unk30; // 30 not seen set yet
  38    uint16_t picture_structure; // 32
  39    uint16_t pad2[3];
  40    uint16_t unk3a; // 3a set on I frame?
  41
  42    uint32_t f_code[4]; // 3c
  43    uint32_t picture_coding_type; // 4c
  44    uint32_t intra_dc_precision; // 50
  45    uint32_t q_scale_type; // 54
  46    uint32_t top_field_first; // 58
  47    uint32_t full_pel_forward_vector; // 5c
  48    uint32_t full_pel_backward_vector; // 60
  49    uint8_t intra_quantizer_matrix[0x40]; // 64
  50    uint8_t non_intra_quantizer_matrix[0x40]; // a4
  51 };
  52
  53 struct mpeg4_picparm_vp {
  54    uint32_t width; // 00 in normal units
  55    uint32_t height; // 04 in normal units
  56    uint32_t unk08; // stride 1
  57    uint32_t unk0c; // stride 2
  58    uint32_t ofs[6]; // 10..24 ofs
  59    uint32_t bucket_size; // 28
  60    uint32_t pad1; // 2c, pad
  61    uint32_t pad2; // 30
  62    uint32_t inter_ring_data_size; // 34
  63
  64    uint32_t trd[2]; // 38, 3c
  65    uint32_t trb[2]; // 40, 44
  66    uint32_t u48; // XXX codec selection? Should test with different values of VdpDecoderProfile
  67    uint16_t f_code_fw; // 4c
  68    uint16_t f_code_bw; // 4e
  69    uint8_t interlaced; // 50
  70
  71    uint8_t quant_type; // bool, written to 528
  72    uint8_t quarter_sample; // bool, written to 548
  73    uint8_t short_video_header; // bool, negated written to 528 shifted by 1
  74    uint8_t u54; // bool, written to 0x740
  75    uint8_t vop_coding_type; // 55
  76    uint8_t rounding_control; // 56
  77    uint8_t alternate_vertical_scan_flag; // 57 bool
  78    uint8_t top_field_first; // bool, written to vuc
  79
  80    uint8_t pad4[3]; // 59, 5a, 5b, contains garbage on blob
  81
  82    uint32_t intra[0x10]; // 5c
  83    uint32_t non_intra[0x10]; // 9c
  84    uint32_t pad5[0x10]; // bc what does this do?
  85    // udc..uff pad?
  86 };
  87
  88 // Full version, with data pumped from BSP
  89 struct vc1_picparm_vp {
  90    uint32_t bucket_size; // 00
  91    uint32_t pad; // 04
  92
  93    uint32_t inter_ring_data_size; // 08
  94    uint32_t unk0c; // stride 1
  95    uint32_t unk10; // stride 2
  96    uint32_t ofs[6]; // 14..28 ofs
  97
  98    uint16_t width; // 2c
  99    uint16_t height; // 2e
 100
 101    uint8_t profile; // 30 0 = simple, 1 = main, 2 = advanced
 102    uint8_t loopfilter; // 31 written into vuc
 103    uint8_t fastuvmc; // 32, written into vuc
 104    uint8_t dquant; // 33
 105
 106    uint8_t overlap; // 34
 107    uint8_t quantizer; // 35
 108    uint8_t u36; // 36, bool
 109    uint8_t pad2; // 37, to align to 0x38
 110 };
 111
 112 struct h264_picparm_vp { // 700..a00
 113    uint16_t width, height;
 114    uint32_t stride1, stride2; // 04 08
 115    uint32_t ofs[6]; // 0c..24 in-image offset
 116
 117    uint32_t tmp_stride;
 118    uint32_t bucket_size; // 28 bucket size
 119    uint32_t inter_ring_data_size; // 2c
 120
 121    unsigned mb_adaptive_frame_field_flag : 1; // 0
 122    unsigned direct_8x8_inference_flag : 1; // 1 0x02: into vuc ofs 56
 123    unsigned weighted_pred_flag : 1; // 2 0x04
 124    unsigned constrained_intra_pred_flag : 1; // 3 0x08: into vuc ofs 68
 125    unsigned is_reference : 1; // 4
 126    unsigned interlace : 1; // 5 field_pic_flag
 127    unsigned bottom_field_flag : 1; // 6
 128    unsigned second_field : 1; // 7 0x80: nfi yet
 129
 130    signed log2_max_frame_num_minus4 : 4; // 31 0..3
 131    unsigned chroma_format_idc : 2; // 31 4..5
 132    unsigned pic_order_cnt_type : 2; // 31 6..7
 133    signed pic_init_qp_minus26 : 6; // 32 0..5
 134    signed chroma_qp_index_offset : 5; // 32 6..10
 135    signed second_chroma_qp_index_offset : 5; // 32 11..15
 136
 137    unsigned weighted_bipred_idc : 2; // 34 0..1
 138    unsigned fifo_dec_index : 7; // 34 2..8
 139    unsigned tmp_idx : 5; // 34 9..13
 140    unsigned frame_number : 16; // 34 14..29
 141    unsigned u34_3030 : 1; // 34 30..30 pp.u34[30:30]
 142    unsigned u34_3131 : 1; // 34 31..31 pad?
 143
 144    uint32_t field_order_cnt[2]; // 38, 3c
 145
 146    struct { // 40
 147       unsigned fifo_idx : 7; // 00 0..6
 148       unsigned tmp_idx : 5; // 00 7..11
 149       unsigned top_is_reference : 1; // 00 12
 150       unsigned bottom_is_reference : 1; // 00 13
 151       unsigned is_long_term : 1; // 00 14
 152       unsigned notseenyet : 1; // 00 15 pad?
 153       unsigned field_pic_flag : 1; // 00 16
 154       unsigned top_field_marking : 4; // 00 17..20
 155       unsigned bottom_field_marking : 4; // 00 21..24
 156       unsigned pad : 7; // 00 d25..31
 157
 158       uint32_t field_order_cnt[2]; // 04,08
 159       uint32_t frame_idx; // 0c
 160    } refs[0x10];
 161
 162    uint8_t m4x4[6][16]; // 140
 163    uint8_t m8x8[2][64]; // 1a0
 164    uint32_t u220; // 220 number of extra reorder_list to append?
 165    uint8_t u224[0x20]; // 224..244 reorder_list append ?
 166    uint8_t nfi244[0xb0]; // add some pad to make sure nulls are read
 167 };
 168
 169 static void
 170 nouveau_vp3_handle_references(struct nouveau_vp3_decoder *dec, struct nouveau_vp3_video_buffer *refs[16], unsigned seq, struct nouveau_vp3_video_buffer *target)
 171 {
 172    unsigned i, idx, empty_spot = ~0;
 173
 174    for (i = 0; i < dec->base.max_references; ++i) {
 175       if (!refs[i])
 176          continue;
 177
 178       idx = refs[i]->valid_ref;
 179       //debug_printf("ref[%i] %p in slot %i\n", i, refs[i], idx);
 180
 181       if (dec->refs[idx].vidbuf != refs[i]) {
 182          debug_printf("%p is not a real ref\n", refs[i]);
 183          // FIXME: Maybe do m2mf copy here if a application really depends on it?
 184          continue;
 185       }
 186
 187       assert(dec->refs[idx].vidbuf == refs[i]);
 188       dec->refs[idx].last_used = seq;
 189    }
 190
 191    if (dec->refs[target->valid_ref].vidbuf == target) {
 192       dec->refs[target->valid_ref].last_used = seq;
 193       return;
 194    }
 195
 196    /* Try to find a real empty spot first, there should be one..
 197     */
 198    for (i = 0; i < dec->base.max_references + 1; ++i) {
 199       if (dec->refs[i].vidbuf == target) {
 200          empty_spot = i;
 201          break;
 202       } else if (!dec->refs[i].last_used) {
 203          empty_spot = i;
 204       } else if (empty_spot == ~0U && dec->refs[i].last_used != seq)
 205          empty_spot = i;
 206    }
 207
 208    assert(empty_spot < dec->base.max_references+1);
 209    dec->refs[empty_spot].last_used = seq;
 210 //   debug_printf("Kicked %p to add %p to slot %i\n", dec->refs[empty_spot].vidbuf, target, empty_spot);
 211    dec->refs[empty_spot].vidbuf = target;
 212    dec->refs[empty_spot].decoded_bottom = dec->refs[empty_spot].decoded_top = 0;
 213    target->valid_ref = empty_spot;
 214 }
 215
 216 static uint32_t
 217 nouveau_vp3_fill_picparm_mpeg12_vp(struct nouveau_vp3_decoder *dec,
 218                                    struct pipe_mpeg12_picture_desc *desc,
 219                                    struct nouveau_vp3_video_buffer *refs[16],
 220                                    unsigned *is_ref,
 221                                    char *map)
 222 {
 223    struct mpeg12_picparm_vp pic_vp_stub = {}, *pic_vp = &pic_vp_stub;
 224    uint32_t i, ret = 0x01010, ring; // !async_shutdown << 16 | watchdog << 12 | irq_record << 4 | unk;
 225    assert(!(dec->base.width & 0xf));
 226    *is_ref = desc->picture_coding_type <= 2;
 227
 228    if (dec->base.profile == PIPE_VIDEO_PROFILE_MPEG1)
 229       pic_vp->picture_structure = 3;
 230    else
 231       pic_vp->picture_structure = desc->picture_structure;
 232
 233    assert(desc->picture_structure != 4);
 234    if (desc->picture_structure == 4) // Untested, but should work
 235       ret |= 0x100;
 236    pic_vp->width = mb(dec->base.width);
 237    pic_vp->height = mb(dec->base.height);
 238    pic_vp->unk08 = pic_vp->unk04 = (dec->base.width+0xf)&~0xf; // Stride
 239
 240    nouveau_vp3_ycbcr_offsets(dec, &pic_vp->ofs[1], &pic_vp->ofs[3], &pic_vp->ofs[4]);
 241    pic_vp->ofs[5] = pic_vp->ofs[3];
 242    pic_vp->ofs[0] = pic_vp->ofs[2] = 0;
 243    nouveau_vp3_inter_sizes(dec, 1, &ring, &pic_vp->bucket_size, &pic_vp->inter_ring_data_size);
 244
 245    pic_vp->alternate_scan = desc->alternate_scan;
 246    pic_vp->pad2[0] = pic_vp->pad2[1] = pic_vp->pad2[2] = 0;
 247    pic_vp->unk30 = desc->picture_structure < 3 && (desc->picture_structure == 2 - desc->top_field_first);
 248    pic_vp->unk3a = (desc->picture_coding_type == 1);
 249    for (i = 0; i < 4; ++i)
 250       pic_vp->f_code[i] = desc->f_code[i/2][i%2] + 1; // FU
 251    pic_vp->picture_coding_type = desc->picture_coding_type;
 252    pic_vp->intra_dc_precision = desc->intra_dc_precision;
 253    pic_vp->q_scale_type = desc->q_scale_type;
 254    pic_vp->top_field_first = desc->top_field_first;
 255    pic_vp->full_pel_forward_vector = desc->full_pel_forward_vector;
 256    pic_vp->full_pel_backward_vector = desc->full_pel_backward_vector;
 257    memcpy(pic_vp->intra_quantizer_matrix, desc->intra_matrix, 0x40);
 258    memcpy(pic_vp->non_intra_quantizer_matrix, desc->non_intra_matrix, 0x40);
 259    memcpy(map, pic_vp, sizeof(*pic_vp));
 260    refs[0] = (struct nouveau_vp3_video_buffer *)desc->ref[0];
 261    refs[!!refs[0]] = (struct nouveau_vp3_video_buffer *)desc->ref[1];
 262    return ret | (dec->base.profile != PIPE_VIDEO_PROFILE_MPEG1);
 263 }
 264
 265 static uint32_t
 266 nouveau_vp3_fill_picparm_mpeg4_vp(struct nouveau_vp3_decoder *dec,
 267                                   struct pipe_mpeg4_picture_desc *desc,
 268                                   struct nouveau_vp3_video_buffer *refs[16],
 269                                   unsigned *is_ref,
 270                                   char *map)
 271 {
 272    struct mpeg4_picparm_vp pic_vp_stub = {}, *pic_vp = &pic_vp_stub;
 273    uint32_t ring, ret = 0x01014; // !async_shutdown << 16 | watchdog << 12 | irq_record << 4 | unk;
 274    *is_ref = desc->vop_coding_type <= 1;
 275
 276    pic_vp->width = dec->base.width;
 277    pic_vp->height = mb(dec->base.height)<<4;
 278    pic_vp->unk0c = pic_vp->unk08 = mb(dec->base.width)<<4; // Stride
 279
 280    nouveau_vp3_ycbcr_offsets(dec, &pic_vp->ofs[1], &pic_vp->ofs[3], &pic_vp->ofs[4]);
 281    pic_vp->ofs[5] = pic_vp->ofs[3];
 282    pic_vp->ofs[0] = pic_vp->ofs[2] = 0;
 283    pic_vp->pad1 = pic_vp->pad2 = 0;
 284    nouveau_vp3_inter_sizes(dec, 1, &ring, &pic_vp->bucket_size, &pic_vp->inter_ring_data_size);
 285
 286    pic_vp->trd[0] = desc->trd[0];
 287    pic_vp->trd[1] = desc->trd[1];
 288    pic_vp->trb[0] = desc->trb[0];
 289    pic_vp->trb[1] = desc->trb[1];
 290    pic_vp->u48 = 0; // Codec?
 291    pic_vp->pad1 = pic_vp->pad2 = 0;
 292    pic_vp->f_code_fw = desc->vop_fcode_forward;
 293    pic_vp->f_code_bw = desc->vop_fcode_backward;
 294    pic_vp->interlaced = desc->interlaced;
 295    pic_vp->quant_type = desc->quant_type;
 296    pic_vp->quarter_sample = desc->quarter_sample;
 297    pic_vp->short_video_header = desc->short_video_header;
 298    pic_vp->u54 = 0;
 299    pic_vp->vop_coding_type = desc->vop_coding_type;
 300    pic_vp->rounding_control = desc->rounding_control;
 301    pic_vp->alternate_vertical_scan_flag = desc->alternate_vertical_scan_flag;
 302    pic_vp->top_field_first = desc->top_field_first;
 303
 304    memcpy(pic_vp->intra, desc->intra_matrix, 0x40);
 305    memcpy(pic_vp->non_intra, desc->non_intra_matrix, 0x40);
 306    memcpy(map, pic_vp, sizeof(*pic_vp));
 307    refs[0] = (struct nouveau_vp3_video_buffer *)desc->ref[0];
 308    refs[!!refs[0]] = (struct nouveau_vp3_video_buffer *)desc->ref[1];
 309    return ret;
 310 }
 311
 312 static uint32_t
 313 nouveau_vp3_fill_picparm_h264_vp(struct nouveau_vp3_decoder *dec,
 314                                  const struct pipe_h264_picture_desc *d,
 315                                  struct nouveau_vp3_video_buffer *refs[16],
 316                                  unsigned *is_ref,
 317                                  char *map)
 318 {
 319    struct h264_picparm_vp stub_h = {}, *h = &stub_h;
 320    unsigned ring, i, j = 0;
 321    assert(offsetof(struct h264_picparm_vp, u224) == 0x224);
 322    *is_ref = d->is_reference;
 323    dec->last_frame_num = d->frame_num;
 324
 325    h->width = mb(dec->base.width);
 326    h->height = mb(dec->base.height);
 327    h->stride1 = h->stride2 = mb(dec->base.width)*16;
 328    nouveau_vp3_ycbcr_offsets(dec, &h->ofs[1], &h->ofs[3], &h->ofs[4]);
 329    h->ofs[5] = h->ofs[3];
 330    h->ofs[0] = h->ofs[2] = 0;
 331    h->tmp_stride = dec->tmp_stride >> 8;
 332    assert(h->tmp_stride);
 333    nouveau_vp3_inter_sizes(dec, d->slice_count, &ring, &h->bucket_size, &h->inter_ring_data_size);
 334
 335    h->u220 = 0;
 336    h->mb_adaptive_frame_field_flag = d->pps->sps->mb_adaptive_frame_field_flag;
 337    h->direct_8x8_inference_flag = d->pps->sps->direct_8x8_inference_flag;
 338    h->weighted_pred_flag = d->pps->weighted_pred_flag;
 339    h->constrained_intra_pred_flag = d->pps->constrained_intra_pred_flag;
 340    h->is_reference = d->is_reference;
 341    h->interlace = d->field_pic_flag;
 342    h->bottom_field_flag = d->bottom_field_flag;
 343    h->second_field = 0; // set in nouveau_vp3_fill_picparm_h264_vp_refs
 344
 345    h->log2_max_frame_num_minus4 = d->pps->sps->log2_max_frame_num_minus4;
 346    h->chroma_format_idc = 1;
 347
 348    h->pic_order_cnt_type = d->pps->sps->pic_order_cnt_type;
 349    h->pic_init_qp_minus26 = d->pps->pic_init_qp_minus26;
 350    h->chroma_qp_index_offset = d->pps->chroma_qp_index_offset;
 351    h->second_chroma_qp_index_offset = d->pps->second_chroma_qp_index_offset;
 352    h->weighted_bipred_idc = d->pps->weighted_bipred_idc;
 353    h->tmp_idx = 0; // set in h264_vp_refs below
 354    h->fifo_dec_index = 0; // always set to 0 to be fifo compatible with other codecs
 355    h->frame_number = d->frame_num;
 356    h->u34_3030 = h->u34_3131 = 0;
 357    h->field_order_cnt[0] = d->field_order_cnt[0];
 358    h->field_order_cnt[1] = d->field_order_cnt[1];
 359    memcpy(h->m4x4, d->pps->ScalingList4x4, sizeof(h->m4x4));
 360    memcpy(h->m8x8, d->pps->ScalingList8x8, sizeof(h->m8x8));
 361    h->u220 = 0;
 362    for (i = 0; i < d->num_ref_frames; ++i) {
 363       if (!d->ref[i])
 364          break;
 365       refs[j] = (struct nouveau_vp3_video_buffer *)d->ref[i];
 366       h->refs[j].fifo_idx = j + 1;
 367       h->refs[j].tmp_idx = refs[j]->valid_ref;
 368       assert(dec->refs[refs[j]->valid_ref].vidbuf == refs[j]);
 369       h->refs[j].field_order_cnt[0] = d->field_order_cnt_list[i][0];
 370       h->refs[j].field_order_cnt[1] = d->field_order_cnt_list[i][1];
 371       h->refs[j].frame_idx = d->frame_num_list[i];
 372       if (!dec->refs[refs[j]->valid_ref].field_pic_flag) {
 373          h->refs[j].top_is_reference = d->top_is_reference[i];
 374          h->refs[j].bottom_is_reference = d->bottom_is_reference[i];
 375       }
 376       h->refs[j].is_long_term = d->is_long_term[i];
 377       h->refs[j].notseenyet = 0;
 378       h->refs[j].field_pic_flag = dec->refs[refs[j]->valid_ref].field_pic_flag;
 379       h->refs[j].top_field_marking =
 380          dec->refs[refs[j]->valid_ref].decoded_top && d->top_is_reference[i] ?
 381          1 + d->is_long_term[i] : 0;
 382       h->refs[j].bottom_field_marking =
 383          dec->refs[refs[j]->valid_ref].decoded_bottom && d->bottom_is_reference[i] ?
 384          1 + d->is_long_term[i] : 0;
 385       h->refs[j].pad = 0;
 386       j++;
 387    }
 388    for (; i < 16; ++i)
 389       assert(!d->ref[i]);
 390    assert(d->num_ref_frames <= dec->base.max_references);
 391
 392    for (; i < d->num_ref_frames; ++i)
 393       h->refs[j].field_pic_flag = d->field_pic_flag;
 394    *(struct h264_picparm_vp *)map = *h;
 395
 396    return 0x1113;
 397 }
 398
 399 static void
 400 nouveau_vp3_fill_picparm_h264_vp_refs(struct nouveau_vp3_decoder *dec,
 401                                       struct pipe_h264_picture_desc *d,
 402                                       struct nouveau_vp3_video_buffer *refs[16],
 403                                       struct nouveau_vp3_video_buffer *target,
 404                                       char *map)
 405 {
 406    struct h264_picparm_vp *h = (struct h264_picparm_vp *)map;
 407    assert(dec->refs[target->valid_ref].vidbuf == target);
 408 //    debug_printf("Target: %p\n", target);
 409
 410    if (!dec->refs[target->valid_ref].decoded_top &&
 411        !dec->refs[target->valid_ref].decoded_bottom)
 412       dec->refs[target->valid_ref].decoded_first = d->bottom_field_flag;
 413    else if (dec->refs[target->valid_ref].decoded_first != d->bottom_field_flag)
 414       h->second_field = 1;
 415
 416    h->tmp_idx = target->valid_ref;
 417    dec->refs[target->valid_ref].field_pic_flag = d->field_pic_flag;
 418    if (!d->field_pic_flag || d->bottom_field_flag)
 419       dec->refs[target->valid_ref].decoded_bottom = 1;
 420    if (!d->field_pic_flag || !d->bottom_field_flag)
 421       dec->refs[target->valid_ref].decoded_top = 1;
 422 }
 423
 424 static uint32_t
 425 nouveau_vp3_fill_picparm_vc1_vp(struct nouveau_vp3_decoder *dec,
 426                                 struct pipe_vc1_picture_desc *d,
 427                                 struct nouveau_vp3_video_buffer *refs[16],
 428                                 unsigned *is_ref,
 429                                 char *map)
 430 {
 431    struct vc1_picparm_vp *vc = (struct vc1_picparm_vp *)map;
 432    unsigned ring;
 433    assert(dec->base.profile != PIPE_VIDEO_PROFILE_VC1_SIMPLE);
 434    *is_ref = d->picture_type <= 1;
 435
 436    nouveau_vp3_ycbcr_offsets(dec, &vc->ofs[1], &vc->ofs[3], &vc->ofs[4]);
 437    vc->ofs[5] = vc->ofs[3];
 438    vc->ofs[0] = vc->ofs[2] = 0;
 439    vc->width = dec->base.width;
 440    vc->height = mb(dec->base.height)<<4;
 441    vc->unk0c = vc->unk10 = mb(dec->base.width)<<4; // Stride
 442    vc->pad = vc->pad2 = 0;
 443    nouveau_vp3_inter_sizes(dec, 1, &ring, &vc->bucket_size, &vc->inter_ring_data_size);
 444    vc->profile = dec->base.profile - PIPE_VIDEO_PROFILE_VC1_SIMPLE;
 445    vc->loopfilter = d->loopfilter;
 446    vc->fastuvmc = d->fastuvmc;
 447    vc->dquant = d->dquant;
 448    vc->overlap = d->overlap;
 449    vc->quantizer = d->quantizer;
 450    vc->u36 = 0; // ? No idea what this one is..
 451    refs[0] = (struct nouveau_vp3_video_buffer *)d->ref[0];
 452    refs[!!refs[0]] = (struct nouveau_vp3_video_buffer *)d->ref[1];
 453    return 0x12;
 454 }
 455
 456 void nouveau_vp3_vp_caps(struct nouveau_vp3_decoder *dec, union pipe_desc desc,
 457                          struct nouveau_vp3_video_buffer *target, unsigned comm_seq,
 458                          unsigned *caps, unsigned *is_ref,
 459                          struct nouveau_vp3_video_buffer *refs[16])
 460 {
 461    struct nouveau_bo *bsp_bo = dec->bsp_bo[comm_seq % NOUVEAU_VP3_VIDEO_QDEPTH];
 462    enum pipe_video_format codec = u_reduce_video_profile(dec->base.profile);
 463    char *vp = bsp_bo->map + VP_OFFSET;
 464
 465    switch (codec){
 466    case PIPE_VIDEO_FORMAT_MPEG12:
 467       *caps = nouveau_vp3_fill_picparm_mpeg12_vp(dec, desc.mpeg12, refs, is_ref, vp);
 468       nouveau_vp3_handle_references(dec, refs, dec->fence_seq, target);
 469       switch (desc.mpeg12->picture_structure) {
 470       case PIPE_MPEG12_PICTURE_STRUCTURE_FIELD_TOP:
 471          dec->refs[target->valid_ref].decoded_top = 1;
 472          break;
 473       case PIPE_MPEG12_PICTURE_STRUCTURE_FIELD_BOTTOM:
 474          dec->refs[target->valid_ref].decoded_bottom = 1;
 475          break;
 476       default:
 477          dec->refs[target->valid_ref].decoded_top = 1;
 478          dec->refs[target->valid_ref].decoded_bottom = 1;
 479          break;
 480       }
 481       return;
 482    case PIPE_VIDEO_FORMAT_MPEG4:
 483       *caps = nouveau_vp3_fill_picparm_mpeg4_vp(dec, desc.mpeg4, refs, is_ref, vp);
 484       nouveau_vp3_handle_references(dec, refs, dec->fence_seq, target);
 485       // XXX: Correct?
 486       if (!desc.mpeg4->interlaced) {
 487          dec->refs[target->valid_ref].decoded_top = 1;
 488          dec->refs[target->valid_ref].decoded_bottom = 1;
 489       } else if (desc.mpeg4->top_field_first) {
 490          if (!dec->refs[target->valid_ref].decoded_top)
 491             dec->refs[target->valid_ref].decoded_top = 1;
 492          else
 493             dec->refs[target->valid_ref].decoded_bottom = 1;
 494       } else {
 495          if (!dec->refs[target->valid_ref].decoded_bottom)
 496             dec->refs[target->valid_ref].decoded_bottom = 1;
 497          else
 498             dec->refs[target->valid_ref].decoded_top = 1;
 499       }
 500       return;
 501    case PIPE_VIDEO_FORMAT_VC1: {
 502       *caps = nouveau_vp3_fill_picparm_vc1_vp(dec, desc.vc1, refs, is_ref, vp);
 503       nouveau_vp3_handle_references(dec, refs, dec->fence_seq, target);
 504       if (desc.vc1->frame_coding_mode == 3)
 505          debug_printf("Field-Interlaced possibly incorrectly handled\n");
 506       dec->refs[target->valid_ref].decoded_top = 1;
 507       dec->refs[target->valid_ref].decoded_bottom = 1;
 508       return;
 509    }
 510    case PIPE_VIDEO_FORMAT_MPEG4_AVC: {
 511       *caps = nouveau_vp3_fill_picparm_h264_vp(dec, desc.h264, refs, is_ref, vp);
 512       nouveau_vp3_handle_references(dec, refs, dec->fence_seq, target);
 513       nouveau_vp3_fill_picparm_h264_vp_refs(dec, desc.h264, refs, target, vp);
 514       return;
 515    }
 516    default: assert(0); return;
 517    }
 518 }