aboutsummaryrefslogtreecommitdiffstats
path: root/libavutil/hwcontext_vaapi.c
blob: 40a85d288c6a936080717514a4f31ef13bab0869 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
/*
 * 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.h"

#if HAVE_VAAPI_X11
#   include <va/va_x11.h>
#endif
#if HAVE_VAAPI_DRM
#   include <va/va_drm.h>
#endif

#if CONFIG_LIBDRM
#   include <va/va_drmcommon.h>
#   include <drm_fourcc.h>
#endif

#include <fcntl.h>
#if HAVE_UNISTD_H
#   include <unistd.h>
#endif


#include "avassert.h"
#include "buffer.h"
#include "common.h"
#include "hwcontext.h"
#include "hwcontext_internal.h"
#include "hwcontext_vaapi.h"
#include "mem.h"
#include "pixdesc.h"
#include "pixfmt.h"

#if CONFIG_LIBDRM
#   include "hwcontext_drm.h"
#endif

typedef struct VAAPIDevicePriv {
#if HAVE_VAAPI_X11
    Display *x11_display;
#endif

    int drm_fd;
} VAAPIDevicePriv;

typedef struct VAAPISurfaceFormat {
    enum AVPixelFormat pix_fmt;
    VAImageFormat image_format;
} VAAPISurfaceFormat;

typedef struct VAAPIDeviceContext {
    // Surface formats which can be used with this device.
    VAAPISurfaceFormat *formats;
    int              nb_formats;
} VAAPIDeviceContext;

typedef struct VAAPIFramesContext {
    // Surface attributes set at create time.
    VASurfaceAttrib *attributes;
    int           nb_attributes;
    // RT format of the underlying surface (Intel driver ignores this anyway).
    unsigned int rt_format;
    // Whether vaDeriveImage works.
    int derive_works;
} VAAPIFramesContext;

typedef struct VAAPIMapping {
    // Handle to the derived or copied image which is mapped.
    VAImage image;
    // The mapping flags actually used.
    int flags;
} VAAPIMapping;

#define MAP(va, rt, av) { \
        VA_FOURCC_ ## va, \
        VA_RT_FORMAT_ ## rt, \
        AV_PIX_FMT_ ## av \
    }
// The map fourcc <-> pix_fmt isn't bijective because of the annoying U/V
// plane swap cases.  The frame handling below tries to hide these.
static const struct {
    unsigned int fourcc;
    unsigned int rt_format;
    enum AVPixelFormat pix_fmt;
} vaapi_format_map[] = {
    MAP(NV12, YUV420,  NV12),
    MAP(YV12, YUV420,  YUV420P), // With U/V planes swapped.
    MAP(IYUV, YUV420,  YUV420P),
  //MAP(I420, YUV420,  YUV420P), // Not in libva but used by Intel driver.
#ifdef VA_FOURCC_YV16
    MAP(YV16, YUV422,  YUV422P), // With U/V planes swapped.
#endif
    MAP(422H, YUV422,  YUV422P),
    MAP(UYVY, YUV422,  UYVY422),
    MAP(YUY2, YUV422,  YUYV422),
    MAP(Y800, YUV400,  GRAY8),
#ifdef VA_FOURCC_P010
    MAP(P010, YUV420_10BPP, P010),
#endif
    MAP(BGRA, RGB32,   BGRA),
    MAP(BGRX, RGB32,   BGR0),
    MAP(RGBA, RGB32,   RGBA),
    MAP(RGBX, RGB32,   RGB0),
#ifdef VA_FOURCC_ABGR
    MAP(ABGR, RGB32,   ABGR),
    MAP(XBGR, RGB32,   0BGR),
#endif
    MAP(ARGB, RGB32,   ARGB),
    MAP(XRGB, RGB32,   0RGB),
};
#undef MAP

static enum AVPixelFormat vaapi_pix_fmt_from_fourcc(unsigned int fourcc)
{
    int i;
    for (i = 0; i < FF_ARRAY_ELEMS(vaapi_format_map); i++)
        if (vaapi_format_map[i].fourcc == fourcc)
            return vaapi_format_map[i].pix_fmt;
    return AV_PIX_FMT_NONE;
}

static int vaapi_get_image_format(AVHWDeviceContext *hwdev,
                                  enum AVPixelFormat pix_fmt,
                                  VAImageFormat **image_format)
{
    VAAPIDeviceContext *ctx = hwdev->internal->priv;
    int i;

    for (i = 0; i < ctx->nb_formats; i++) {
        if (ctx->formats[i].pix_fmt == pix_fmt) {
            if (image_format)
                *image_format = &ctx->formats[i].image_format;
            return 0;
        }
    }
    return AVERROR(EINVAL);
}

static int vaapi_frames_get_constraints(AVHWDeviceContext *hwdev,
                                        const void *hwconfig,
                                        AVHWFramesConstraints *constraints)
{
    AVVAAPIDeviceContext *hwctx = hwdev->hwctx;
    const AVVAAPIHWConfig *config = hwconfig;
    VAAPIDeviceContext *ctx = hwdev->internal->priv;
    VASurfaceAttrib *attr_list = NULL;
    VAStatus vas;
    enum AVPixelFormat pix_fmt;
    unsigned int fourcc;
    int err, i, j, attr_count, pix_fmt_count;

    if (config &&
        !(hwctx->driver_quirks & AV_VAAPI_DRIVER_QUIRK_SURFACE_ATTRIBUTES)) {
        attr_count = 0;
        vas = vaQuerySurfaceAttributes(hwctx->display, config->config_id,
                                       0, &attr_count);
        if (vas != VA_STATUS_SUCCESS) {
            av_log(hwdev, AV_LOG_ERROR, "Failed to query surface attributes: "
                   "%d (%s).\n", vas, vaErrorStr(vas));
            err = AVERROR(ENOSYS);
            goto fail;
        }

        attr_list = av_malloc(attr_count * sizeof(*attr_list));
        if (!attr_list) {
            err = AVERROR(ENOMEM);
            goto fail;
        }

        vas = vaQuerySurfaceAttributes(hwctx->display, config->config_id,
                                       attr_list, &attr_count);
        if (vas != VA_STATUS_SUCCESS) {
            av_log(hwdev, AV_LOG_ERROR, "Failed to query surface attributes: "
                   "%d (%s).\n", vas, vaErrorStr(vas));
            err = AVERROR(ENOSYS);
            goto fail;
        }

        pix_fmt_count = 0;
        for (i = 0; i < attr_count; i++) {
            switch (attr_list[i].type) {
            case VASurfaceAttribPixelFormat:
                fourcc = attr_list[i].value.value.i;
                pix_fmt = vaapi_pix_fmt_from_fourcc(fourcc);
                if (pix_fmt != AV_PIX_FMT_NONE) {
                    ++pix_fmt_count;
                } else {
                    // Something unsupported - ignore.
                }
                break;
            case VASurfaceAttribMinWidth:
                constraints->min_width  = attr_list[i].value.value.i;
                break;
            case VASurfaceAttribMinHeight:
                constraints->min_height = attr_list[i].value.value.i;
                break;
            case VASurfaceAttribMaxWidth:
                constraints->max_width  = attr_list[i].value.value.i;
                break;
            case VASurfaceAttribMaxHeight:
                constraints->max_height = attr_list[i].value.value.i;
                break;
            }
        }
        if (pix_fmt_count == 0) {
            // Nothing usable found.  Presumably there exists something which
            // works, so leave the set null to indicate unknown.
            constraints->valid_sw_formats = NULL;
        } else {
            constraints->valid_sw_formats = av_malloc_array(pix_fmt_count + 1,
                                                            sizeof(pix_fmt));
            if (!constraints->valid_sw_formats) {
                err = AVERROR(ENOMEM);
                goto fail;
            }

            for (i = j = 0; i < attr_count; i++) {
                if (attr_list[i].type != VASurfaceAttribPixelFormat)
                    continue;
                fourcc = attr_list[i].value.value.i;
                pix_fmt = vaapi_pix_fmt_from_fourcc(fourcc);
                if (pix_fmt != AV_PIX_FMT_NONE)
                    constraints->valid_sw_formats[j++] = pix_fmt;
            }
            av_assert0(j == pix_fmt_count);
            constraints->valid_sw_formats[j] = AV_PIX_FMT_NONE;
        }
    } else {
        // No configuration supplied.
        // Return the full set of image formats known by the implementation.
        constraints->valid_sw_formats = av_malloc_array(ctx->nb_formats + 1,
                                                        sizeof(pix_fmt));
        if (!constraints->valid_sw_formats) {
            err = AVERROR(ENOMEM);
            goto fail;
        }
        for (i = 0; i < ctx->nb_formats; i++)
            constraints->valid_sw_formats[i] = ctx->formats[i].pix_fmt;
        constraints->valid_sw_formats[i] = AV_PIX_FMT_NONE;
    }

    constraints->valid_hw_formats = av_malloc_array(2, sizeof(pix_fmt));
    if (!constraints->valid_hw_formats) {
        err = AVERROR(ENOMEM);
        goto fail;
    }
    constraints->valid_hw_formats[0] = AV_PIX_FMT_VAAPI;
    constraints->valid_hw_formats[1] = AV_PIX_FMT_NONE;

    err = 0;
fail:
    av_freep(&attr_list);
    return err;
}

static const struct {
    const char *friendly_name;
    const char *match_string;
    unsigned int quirks;
} vaapi_driver_quirks_table[] = {
    {
        "Intel i965 (Quick Sync)",
        "i965",
        AV_VAAPI_DRIVER_QUIRK_RENDER_PARAM_BUFFERS,
    },
    {
        "Intel iHD",
        "ubit",
        AV_VAAPI_DRIVER_QUIRK_ATTRIB_MEMTYPE,
    },
    {
        "VDPAU wrapper",
        "Splitted-Desktop Systems VDPAU backend for VA-API",
        AV_VAAPI_DRIVER_QUIRK_SURFACE_ATTRIBUTES,
    },
};

static int vaapi_device_init(AVHWDeviceContext *hwdev)
{
    VAAPIDeviceContext *ctx = hwdev->internal->priv;
    AVVAAPIDeviceContext *hwctx = hwdev->hwctx;
    VAImageFormat *image_list = NULL;
    VAStatus vas;
    const char *vendor_string;
    int err, i, image_count;
    enum AVPixelFormat pix_fmt;
    unsigned int fourcc;

    image_count = vaMaxNumImageFormats(hwctx->display);
    if (image_count <= 0) {
        err = AVERROR(EIO);
        goto fail;
    }
    image_list = av_malloc(image_count * sizeof(*image_list));
    if (!image_list) {
        err = AVERROR(ENOMEM);
        goto fail;
    }
    vas = vaQueryImageFormats(hwctx->display, image_list, &image_count);
    if (vas != VA_STATUS_SUCCESS) {
        err = AVERROR(EIO);
        goto fail;
    }

    ctx->formats  = av_malloc(image_count * sizeof(*ctx->formats));
    if (!ctx->formats) {
        err = AVERROR(ENOMEM);
        goto fail;
    }
    ctx->nb_formats = 0;
    for (i = 0; i < image_count; i++) {
        fourcc  = image_list[i].fourcc;
        pix_fmt = vaapi_pix_fmt_from_fourcc(fourcc);
        if (pix_fmt == AV_PIX_FMT_NONE) {
            av_log(hwdev, AV_LOG_DEBUG, "Format %#x -> unknown.\n",
                   fourcc);
        } else {
            av_log(hwdev, AV_LOG_DEBUG, "Format %#x -> %s.\n",
                   fourcc, av_get_pix_fmt_name(pix_fmt));
            ctx->formats[ctx->nb_formats].pix_fmt      = pix_fmt;
            ctx->formats[ctx->nb_formats].image_format = image_list[i];
            ++ctx->nb_formats;
        }
    }

    if (hwctx->driver_quirks & AV_VAAPI_DRIVER_QUIRK_USER_SET) {
        av_log(hwdev, AV_LOG_VERBOSE, "Not detecting driver: "
               "quirks set by user.\n");
    } else {
        // Detect the driver in use and set quirk flags if necessary.
        vendor_string = vaQueryVendorString(hwctx->display);
        hwctx->driver_quirks = 0;
        if (vendor_string) {
            for (i = 0; i < FF_ARRAY_ELEMS(vaapi_driver_quirks_table); i++) {
                if (strstr(vendor_string,
                           vaapi_driver_quirks_table[i].match_string)) {
                    av_log(hwdev, AV_LOG_VERBOSE, "Matched \"%s\" as known "
                           "driver \"%s\".\n", vendor_string,
                           vaapi_driver_quirks_table[i].friendly_name);
                    hwctx->driver_quirks |=
                        vaapi_driver_quirks_table[i].quirks;
                    break;
                }
            }
            if (!(i < FF_ARRAY_ELEMS(vaapi_driver_quirks_table))) {
                av_log(hwdev, AV_LOG_VERBOSE, "Unknown driver \"%s\", "
                       "assuming standard behaviour.\n", vendor_string);
            }
        }
    }

    av_free(image_list);
    return 0;
fail:
    av_freep(&ctx->formats);
    av_free(image_list);
    return err;
}

static void vaapi_device_uninit(AVHWDeviceContext *hwdev)
{
    VAAPIDeviceContext *ctx = hwdev->internal->priv;

    av_freep(&ctx->formats);
}

static void vaapi_buffer_free(void *opaque, uint8_t *data)
{
    AVHWFramesContext     *hwfc = opaque;
    AVVAAPIDeviceContext *hwctx = hwfc->device_ctx->hwctx;
    VASurfaceID surface_id;
    VAStatus vas;

    surface_id = (VASurfaceID)(uintptr_t)data;

    vas = vaDestroySurfaces(hwctx->display, &surface_id, 1);
    if (vas != VA_STATUS_SUCCESS) {
        av_log(hwfc, AV_LOG_ERROR, "Failed to destroy surface %#x: "
               "%d (%s).\n", surface_id, vas, vaErrorStr(vas));
    }
}

static AVBufferRef *vaapi_pool_alloc(void *opaque, int size)
{
    AVHWFramesContext     *hwfc = opaque;
    VAAPIFramesContext     *ctx = hwfc->internal->priv;
    AVVAAPIDeviceContext *hwctx = hwfc->device_ctx->hwctx;
    AVVAAPIFramesContext  *avfc = hwfc->hwctx;
    VASurfaceID surface_id;
    VAStatus vas;
    AVBufferRef *ref;

    if (hwfc->initial_pool_size > 0 &&
        avfc->nb_surfaces >= hwfc->initial_pool_size)
        return NULL;

    vas = vaCreateSurfaces(hwctx->display, ctx->rt_format,
                           hwfc->width, hwfc->height,
                           &surface_id, 1,
                           ctx->attributes, ctx->nb_attributes);
    if (vas != VA_STATUS_SUCCESS) {
        av_log(hwfc, AV_LOG_ERROR, "Failed to create surface: "
               "%d (%s).\n", vas, vaErrorStr(vas));
        return NULL;
    }
    av_log(hwfc, AV_LOG_DEBUG, "Created surface %#x.\n", surface_id);

    ref = av_buffer_create((uint8_t*)(uintptr_t)surface_id,
                           sizeof(surface_id), &vaapi_buffer_free,
                           hwfc, AV_BUFFER_FLAG_READONLY);
    if (!ref) {
        vaDestroySurfaces(hwctx->display, &surface_id, 1);
        return NULL;
    }

    if (hwfc->initial_pool_size > 0) {
        // This is a fixed-size pool, so we must still be in the initial
        // allocation sequence.
        av_assert0(avfc->nb_surfaces < hwfc->initial_pool_size);
        avfc->surface_ids[avfc->nb_surfaces] = surface_id;
        ++avfc->nb_surfaces;
    }

    return ref;
}

static int vaapi_frames_init(AVHWFramesContext *hwfc)
{
    AVVAAPIFramesContext  *avfc = hwfc->hwctx;
    VAAPIFramesContext     *ctx = hwfc->internal->priv;
    AVVAAPIDeviceContext *hwctx = hwfc->device_ctx->hwctx;
    VAImageFormat *expected_format;
    AVBufferRef *test_surface = NULL;
    VASurfaceID test_surface_id;
    VAImage test_image;
    VAStatus vas;
    int err, i;
    unsigned int fourcc, rt_format;

    for (i = 0; i < FF_ARRAY_ELEMS(vaapi_format_map); i++) {
        if (vaapi_format_map[i].pix_fmt == hwfc->sw_format) {
            fourcc    = vaapi_format_map[i].fourcc;
            rt_format = vaapi_format_map[i].rt_format;
            break;
        }
    }
    if (i >= FF_ARRAY_ELEMS(vaapi_format_map)) {
        av_log(hwfc, AV_LOG_ERROR, "Unsupported format: %s.\n",
               av_get_pix_fmt_name(hwfc->sw_format));
        return AVERROR(EINVAL);
    }

    if (!hwfc->pool) {
        if (!(hwctx->driver_quirks & AV_VAAPI_DRIVER_QUIRK_SURFACE_ATTRIBUTES)) {
            int need_memory_type = !(hwctx->driver_quirks & AV_VAAPI_DRIVER_QUIRK_ATTRIB_MEMTYPE);
            int need_pixel_format = 1;
            for (i = 0; i < avfc->nb_attributes; i++) {
                if (ctx->attributes[i].type == VASurfaceAttribMemoryType)
                    need_memory_type  = 0;
                if (ctx->attributes[i].type == VASurfaceAttribPixelFormat)
                    need_pixel_format = 0;
            }
            ctx->nb_attributes =
                avfc->nb_attributes + need_memory_type + need_pixel_format;

            ctx->attributes = av_malloc(ctx->nb_attributes *
                                        sizeof(*ctx->attributes));
            if (!ctx->attributes) {
                err = AVERROR(ENOMEM);
                goto fail;
            }

            for (i = 0; i < avfc->nb_attributes; i++)
                ctx->attributes[i] = avfc->attributes[i];
            if (need_memory_type) {
                ctx->attributes[i++] = (VASurfaceAttrib) {
                    .type          = VASurfaceAttribMemoryType,
                    .flags         = VA_SURFACE_ATTRIB_SETTABLE,
                    .value.type    = VAGenericValueTypeInteger,
                    .value.value.i = VA_SURFACE_ATTRIB_MEM_TYPE_VA,
                };
            }
            if (need_pixel_format) {
                ctx->attributes[i++] = (VASurfaceAttrib) {
                    .type          = VASurfaceAttribPixelFormat,
                    .flags         = VA_SURFACE_ATTRIB_SETTABLE,
                    .value.type    = VAGenericValueTypeInteger,
                    .value.value.i = fourcc,
                };
            }
            av_assert0(i == ctx->nb_attributes);
        } else {
            ctx->attributes = NULL;
            ctx->nb_attributes = 0;
        }

        ctx->rt_format = rt_format;

        if (hwfc->initial_pool_size > 0) {
            // This pool will be usable as a render target, so we need to store
            // all of the surface IDs somewhere that vaCreateContext() calls
            // will be able to access them.
            avfc->nb_surfaces = 0;
            avfc->surface_ids = av_malloc(hwfc->initial_pool_size *
                                          sizeof(*avfc->surface_ids));
            if (!avfc->surface_ids) {
                err = AVERROR(ENOMEM);
                goto fail;
            }
        } else {
            // This pool allows dynamic sizing, and will not be usable as a
            // render target.
            avfc->nb_surfaces = 0;
            avfc->surface_ids = NULL;
        }

        hwfc->internal->pool_internal =
            av_buffer_pool_init2(sizeof(VASurfaceID), hwfc,
                                 &vaapi_pool_alloc, NULL);
        if (!hwfc->internal->pool_internal) {
            av_log(hwfc, AV_LOG_ERROR, "Failed to create VAAPI surface pool.\n");
            err = AVERROR(ENOMEM);
            goto fail;
        }
    }

    // Allocate a single surface to test whether vaDeriveImage() is going
    // to work for the specific configuration.
    if (hwfc->pool) {
        test_surface = av_buffer_pool_get(hwfc->pool);
        if (!test_surface) {
            av_log(hwfc, AV_LOG_ERROR, "Unable to allocate a surface from "
                   "user-configured buffer pool.\n");
            err = AVERROR(ENOMEM);
            goto fail;
        }
    } else {
        test_surface = av_buffer_pool_get(hwfc->internal->pool_internal);
        if (!test_surface) {
            av_log(hwfc, AV_LOG_ERROR, "Unable to allocate a surface from "
                   "internal buffer pool.\n");
            err = AVERROR(ENOMEM);
            goto fail;
        }
    }
    test_surface_id = (VASurfaceID)(uintptr_t)test_surface->data;

    ctx->derive_works = 0;

    err = vaapi_get_image_format(hwfc->device_ctx,
                                 hwfc->sw_format, &expected_format);
    if (err == 0) {
        vas = vaDeriveImage(hwctx->display, test_surface_id, &test_image);
        if (vas == VA_STATUS_SUCCESS) {
            if (expected_format->fourcc == test_image.format.fourcc) {
                av_log(hwfc, AV_LOG_DEBUG, "Direct mapping possible.\n");
                ctx->derive_works = 1;
            } else {
                av_log(hwfc, AV_LOG_DEBUG, "Direct mapping disabled: "
                       "derived image format %08x does not match "
                       "expected format %08x.\n",
                       expected_format->fourcc, test_image.format.fourcc);
            }
            vaDestroyImage(hwctx->display, test_image.image_id);
        } else {
            av_log(hwfc, AV_LOG_DEBUG, "Direct mapping disabled: "
                   "deriving image does not work: "
                   "%d (%s).\n", vas, vaErrorStr(vas));
        }
    } else {
        av_log(hwfc, AV_LOG_DEBUG, "Direct mapping disabled: "
               "image format is not supported.\n");
    }

    av_buffer_unref(&test_surface);
    return 0;

fail:
    av_buffer_unref(&test_surface);
    av_freep(&avfc->surface_ids);
    av_freep(&ctx->attributes);
    return err;
}

static void vaapi_frames_uninit(AVHWFramesContext *hwfc)
{
    AVVAAPIFramesContext *avfc = hwfc->hwctx;
    VAAPIFramesContext    *ctx = hwfc->internal->priv;

    av_freep(&avfc->surface_ids);
    av_freep(&ctx->attributes);
}

static int vaapi_get_buffer(AVHWFramesContext *hwfc, AVFrame *frame)
{
    frame->buf[0] = av_buffer_pool_get(hwfc->pool);
    if (!frame->buf[0])
        return AVERROR(ENOMEM);

    frame->data[3] = frame->buf[0]->data;
    frame->format  = AV_PIX_FMT_VAAPI;
    frame->width   = hwfc->width;
    frame->height  = hwfc->height;

    return 0;
}

static int vaapi_transfer_get_formats(AVHWFramesContext *hwfc,
                                      enum AVHWFrameTransferDirection dir,
                                      enum AVPixelFormat **formats)
{
    VAAPIDeviceContext *ctx = hwfc->device_ctx->internal->priv;
    enum AVPixelFormat *pix_fmts, preferred_format;
    int i, k;

    preferred_format = hwfc->sw_format;

    pix_fmts = av_malloc((ctx->nb_formats + 1) * sizeof(*pix_fmts));
    if (!pix_fmts)
        return AVERROR(ENOMEM);

    pix_fmts[0] = preferred_format;
    k = 1;
    for (i = 0; i < ctx->nb_formats; i++) {
        if (ctx->formats[i].pix_fmt == preferred_format)
            continue;
        av_assert0(k < ctx->nb_formats);
        pix_fmts[k++] = ctx->formats[i].pix_fmt;
    }
    av_assert0(k == ctx->nb_formats);
    pix_fmts[k] = AV_PIX_FMT_NONE;

    *formats = pix_fmts;
    return 0;
}

static void vaapi_unmap_frame(AVHWFramesContext *hwfc,
                              HWMapDescriptor *hwmap)
{
    AVVAAPIDeviceContext *hwctx = hwfc->device_ctx->hwctx;
    VAAPIMapping           *map = hwmap->priv;
    VASurfaceID surface_id;
    VAStatus vas;

    surface_id = (VASurfaceID)(uintptr_t)hwmap->source->data[3];
    av_log(hwfc, AV_LOG_DEBUG, "Unmap surface %#x.\n", surface_id);

    vas = vaUnmapBuffer(hwctx->display, map->image.buf);
    if (vas != VA_STATUS_SUCCESS) {
        av_log(hwfc, AV_LOG_ERROR, "Failed to unmap image from surface "
               "%#x: %d (%s).\n", surface_id, vas, vaErrorStr(vas));
    }

    if ((map->flags & AV_HWFRAME_MAP_WRITE) &&
        !(map->flags & AV_HWFRAME_MAP_DIRECT)) {
        vas = vaPutImage(hwctx->display, surface_id, map->image.image_id,
                         0, 0, hwfc->width, hwfc->height,
                         0, 0, hwfc->width, hwfc->height);
        if (vas != VA_STATUS_SUCCESS) {
            av_log(hwfc, AV_LOG_ERROR, "Failed to write image to surface "
                   "%#x: %d (%s).\n", surface_id, vas, vaErrorStr(vas));
        }
    }

    vas = vaDestroyImage(hwctx->display, map->image.image_id);
    if (vas != VA_STATUS_SUCCESS) {
        av_log(hwfc, AV_LOG_ERROR, "Failed to destroy image from surface "
               "%#x: %d (%s).\n", surface_id, vas, vaErrorStr(vas));
    }

    av_free(map);
}

static int vaapi_map_frame(AVHWFramesContext *hwfc,
                           AVFrame *dst, const AVFrame *src, int flags)
{
    AVVAAPIDeviceContext *hwctx = hwfc->device_ctx->hwctx;
    VAAPIFramesContext *ctx = hwfc->internal->priv;
    VASurfaceID surface_id;
    VAImageFormat *image_format;
    VAAPIMapping *map;
    VAStatus vas;
    void *address = NULL;
    int err, i;

    surface_id = (VASurfaceID)(uintptr_t)src->data[3];
    av_log(hwfc, AV_LOG_DEBUG, "Map surface %#x.\n", surface_id);

    if (!ctx->derive_works && (flags & AV_HWFRAME_MAP_DIRECT)) {
        // Requested direct mapping but it is not possible.
        return AVERROR(EINVAL);
    }
    if (dst->format == AV_PIX_FMT_NONE)
        dst->format = hwfc->sw_format;
    if (dst->format != hwfc->sw_format && (flags & AV_HWFRAME_MAP_DIRECT)) {
        // Requested direct mapping but the formats do not match.
        return AVERROR(EINVAL);
    }

    err = vaapi_get_image_format(hwfc->device_ctx, dst->format, &image_format);
    if (err < 0) {
        // Requested format is not a valid output format.
        return AVERROR(EINVAL);
    }

    map = av_malloc(sizeof(*map));
    if (!map)
        return AVERROR(ENOMEM);
    map->flags = flags;
    map->image.image_id = VA_INVALID_ID;

    vas = vaSyncSurface(hwctx->display, surface_id);
    if (vas != VA_STATUS_SUCCESS) {
        av_log(hwfc, AV_LOG_ERROR, "Failed to sync surface "
               "%#x: %d (%s).\n", surface_id, vas, vaErrorStr(vas));
        err = AVERROR(EIO);
        goto fail;
    }

    // The memory which we map using derive need not be connected to the CPU
    // in a way conducive to fast access.  On Gen7-Gen9 Intel graphics, the
    // memory is mappable but not cached, so normal memcpy()-like access is
    // very slow to read it (but writing is ok).  It is possible to read much
    // faster with a copy routine which is aware of the limitation, but we
    // assume for now that the user is not aware of that and would therefore
    // prefer not to be given direct-mapped memory if they request read access.
    if (ctx->derive_works && dst->format == hwfc->sw_format &&
        ((flags & AV_HWFRAME_MAP_DIRECT) || !(flags & AV_HWFRAME_MAP_READ))) {
        vas = vaDeriveImage(hwctx->display, surface_id, &map->image);
        if (vas != VA_STATUS_SUCCESS) {
            av_log(hwfc, AV_LOG_ERROR, "Failed to derive image from "
                   "surface %#x: %d (%s).\n",
                   surface_id, vas, vaErrorStr(vas));
            err = AVERROR(EIO);
            goto fail;
        }
        if (map->image.format.fourcc != image_format->fourcc) {
            av_log(hwfc, AV_LOG_ERROR, "Derive image of surface %#x "
                   "is in wrong format: expected %#08x, got %#08x.\n",
                   surface_id, image_format->fourcc, map->image.format.fourcc);
            err = AVERROR(EIO);
            goto fail;
        }
        map->flags |= AV_HWFRAME_MAP_DIRECT;
    } else {
        vas = vaCreateImage(hwctx->display, image_format,
                            hwfc->width, hwfc->height, &map->image);
        if (vas != VA_STATUS_SUCCESS) {
            av_log(hwfc, AV_LOG_ERROR, "Failed to create image for "
                   "surface %#x: %d (%s).\n",
                   surface_id, vas, vaErrorStr(vas));
            err = AVERROR(EIO);
            goto fail;
        }
        if (!(flags & AV_HWFRAME_MAP_OVERWRITE)) {
            vas = vaGetImage(hwctx->display, surface_id, 0, 0,
                             hwfc->width, hwfc->height, map->image.image_id);
            if (vas != VA_STATUS_SUCCESS) {
                av_log(hwfc, AV_LOG_ERROR, "Failed to read image from "
                       "surface %#x: %d (%s).\n",
                       surface_id, vas, vaErrorStr(vas));
                err = AVERROR(EIO);
                goto fail;
            }
        }
    }

    vas = vaMapBuffer(hwctx->display, map->image.buf, &address);
    if (vas != VA_STATUS_SUCCESS) {
        av_log(hwfc, AV_LOG_ERROR, "Failed to map image from surface "
               "%#x: %d (%s).\n", surface_id, vas, vaErrorStr(vas));
        err = AVERROR(EIO);
        goto fail;
    }

    err = ff_hwframe_map_create(src->hw_frames_ctx,
                                dst, src, &vaapi_unmap_frame, map);
    if (err < 0)
        goto fail;

    dst->width  = src->width;
    dst->height = src->height;

    for (i = 0; i < map->image.num_planes; i++) {
        dst->data[i] = (uint8_t*)address + map->image.offsets[i];
        dst->linesize[i] = map->image.pitches[i];
    }
    if (
#ifdef VA_FOURCC_YV16
        map->image.format.fourcc == VA_FOURCC_YV16 ||
#endif
        map->image.format.fourcc == VA_FOURCC_YV12) {
        // Chroma planes are YVU rather than YUV, so swap them.
        FFSWAP(uint8_t*, dst->data[1], dst->data[2]);
    }

    return 0;

fail:
    if (map) {
        if (address)
            vaUnmapBuffer(hwctx->display, map->image.buf);
        if (map->image.image_id != VA_INVALID_ID)
            vaDestroyImage(hwctx->display, map->image.image_id);
        av_free(map);
    }
    return err;
}

static int vaapi_transfer_data_from(AVHWFramesContext *hwfc,
                                    AVFrame *dst, const AVFrame *src)
{
    AVFrame *map;
    int err;

    if (dst->width > hwfc->width || dst->height > hwfc->height)
        return AVERROR(EINVAL);

    map = av_frame_alloc();
    if (!map)
        return AVERROR(ENOMEM);
    map->format = dst->format;

    err = vaapi_map_frame(hwfc, map, src, AV_HWFRAME_MAP_READ);
    if (err)
        goto fail;

    map->width  = dst->width;
    map->height = dst->height;

    err = av_frame_copy(dst, map);
    if (err)
        goto fail;

    err = 0;
fail:
    av_frame_free(&map);
    return err;
}

static int vaapi_transfer_data_to(AVHWFramesContext *hwfc,
                                  AVFrame *dst, const AVFrame *src)
{
    AVFrame *map;
    int err;

    if (src->width > hwfc->width || src->height > hwfc->height)
        return AVERROR(EINVAL);

    map = av_frame_alloc();
    if (!map)
        return AVERROR(ENOMEM);
    map->format = src->format;

    err = vaapi_map_frame(hwfc, map, dst, AV_HWFRAME_MAP_WRITE | AV_HWFRAME_MAP_OVERWRITE);
    if (err)
        goto fail;

    map->width  = src->width;
    map->height = src->height;

    err = av_frame_copy(map, src);
    if (err)
        goto fail;

    err = 0;
fail:
    av_frame_free(&map);
    return err;
}

static int vaapi_map_to_memory(AVHWFramesContext *hwfc, AVFrame *dst,
                               const AVFrame *src, int flags)
{
    int err;

    if (dst->format != AV_PIX_FMT_NONE) {
        err = vaapi_get_image_format(hwfc->device_ctx, dst->format, NULL);
        if (err < 0)
            return AVERROR(ENOSYS);
    }

    err = vaapi_map_frame(hwfc, dst, src, flags);
    if (err)
        return err;

    err = av_frame_copy_props(dst, src);
    if (err)
        return err;

    return 0;
}

#if CONFIG_LIBDRM

#define DRM_MAP(va, layers, ...) { \
        VA_FOURCC_ ## va, \
        layers, \
        { __VA_ARGS__ } \
    }
static const struct {
    uint32_t va_fourcc;
    int   nb_layer_formats;
    uint32_t layer_formats[AV_DRM_MAX_PLANES];
} vaapi_drm_format_map[] = {
#ifdef DRM_FORMAT_R8
    DRM_MAP(NV12, 2, DRM_FORMAT_R8,  DRM_FORMAT_RG88),
#endif
    DRM_MAP(NV12, 1, DRM_FORMAT_NV12),
#if defined(VA_FOURCC_P010) && defined(DRM_FORMAT_R16)
    DRM_MAP(P010, 2, DRM_FORMAT_R16, DRM_FORMAT_RG1616),
#endif
    DRM_MAP(BGRA, 1, DRM_FORMAT_ARGB8888),
    DRM_MAP(BGRX, 1, DRM_FORMAT_XRGB8888),
    DRM_MAP(RGBA, 1, DRM_FORMAT_ABGR8888),
    DRM_MAP(RGBX, 1, DRM_FORMAT_XBGR8888),
#ifdef VA_FOURCC_ABGR
    DRM_MAP(ABGR, 1, DRM_FORMAT_RGBA8888),
    DRM_MAP(XBGR, 1, DRM_FORMAT_RGBX8888),
#endif
    DRM_MAP(ARGB, 1, DRM_FORMAT_BGRA8888),
    DRM_MAP(XRGB, 1, DRM_FORMAT_BGRX8888),
};
#undef DRM_MAP

static void vaapi_unmap_from_drm(AVHWFramesContext *dst_fc,
                                 HWMapDescriptor *hwmap)
{
    AVVAAPIDeviceContext *dst_dev = dst_fc->device_ctx->hwctx;

    VASurfaceID surface_id = (VASurfaceID)(uintptr_t)hwmap->priv;

    av_log(dst_fc, AV_LOG_DEBUG, "Destroy surface %#x.\n", surface_id);

    vaDestroySurfaces(dst_dev->display, &surface_id, 1);
}

static int vaapi_map_from_drm(AVHWFramesContext *src_fc, AVFrame *dst,
                              const AVFrame *src, int flags)
{
    AVHWFramesContext      *dst_fc =
        (AVHWFramesContext*)dst->hw_frames_ctx->data;
    AVVAAPIDeviceContext  *dst_dev = dst_fc->device_ctx->hwctx;
    const AVDRMFrameDescriptor *desc;
    VASurfaceID surface_id;
    VAStatus vas;
    uint32_t va_fourcc, va_rt_format;
    int err, i, j, k;

    unsigned long buffer_handle;
    VASurfaceAttribExternalBuffers buffer_desc;
    VASurfaceAttrib attrs[2] = {
        {
            .type  = VASurfaceAttribMemoryType,
            .flags = VA_SURFACE_ATTRIB_SETTABLE,
            .value.type    = VAGenericValueTypeInteger,
            .value.value.i = VA_SURFACE_ATTRIB_MEM_TYPE_DRM_PRIME,
        },
        {
            .type  = VASurfaceAttribExternalBufferDescriptor,
            .flags = VA_SURFACE_ATTRIB_SETTABLE,
            .value.type    = VAGenericValueTypePointer,
            .value.value.p = &buffer_desc,
        }
    };

    desc = (AVDRMFrameDescriptor*)src->data[0];

    if (desc->nb_objects != 1) {
        av_log(dst_fc, AV_LOG_ERROR, "VAAPI can only map frames "
               "made from a single DRM object.\n");
        return AVERROR(EINVAL);
    }

    va_fourcc = 0;
    for (i = 0; i < FF_ARRAY_ELEMS(vaapi_drm_format_map); i++) {
        if (desc->nb_layers != vaapi_drm_format_map[i].nb_layer_formats)
            continue;
        for (j = 0; j < desc->nb_layers; j++) {
            if (desc->layers[j].format !=
                vaapi_drm_format_map[i].layer_formats[j])
                break;
        }
        if (j != desc->nb_layers)
            continue;
        va_fourcc = vaapi_drm_format_map[i].va_fourcc;
        break;
    }
    if (!va_fourcc) {
        av_log(dst_fc, AV_LOG_ERROR, "DRM format not supported "
               "by VAAPI.\n");
        return AVERROR(EINVAL);
    }

    av_log(dst_fc, AV_LOG_DEBUG, "Map DRM object %d to VAAPI as "
           "%08x.\n", desc->objects[0].fd, va_fourcc);

    for (i = 0; i < FF_ARRAY_ELEMS(vaapi_format_map); i++) {
        if (vaapi_format_map[i].fourcc == va_fourcc)
            va_rt_format = vaapi_format_map[i].rt_format;
    }

    buffer_handle = desc->objects[0].fd;
    buffer_desc.pixel_format = va_fourcc;
    buffer_desc.width        = src_fc->width;
    buffer_desc.height       = src_fc->height;
    buffer_desc.data_size    = desc->objects[0].size;
    buffer_desc.buffers      = &buffer_handle;
    buffer_desc.num_buffers  = 1;
    buffer_desc.flags        = 0;

    k = 0;
    for (i = 0; i < desc->nb_layers; i++) {
        for (j = 0; j < desc->layers[i].nb_planes; j++) {
            buffer_desc.pitches[k] = desc->layers[i].planes[j].pitch;
            buffer_desc.offsets[k] = desc->layers[i].planes[j].offset;
            ++k;
        }
    }
    buffer_desc.num_planes = k;

    vas = vaCreateSurfaces(dst_dev->display, va_rt_format,
                           src->width, src->height,
                           &surface_id, 1,
                           attrs, FF_ARRAY_ELEMS(attrs));
    if (vas != VA_STATUS_SUCCESS) {
        av_log(dst_fc, AV_LOG_ERROR, "Failed to create surface from DRM "
               "object: %d (%s).\n", vas, vaErrorStr(vas));
        return AVERROR(EIO);
    }
    av_log(dst_fc, AV_LOG_DEBUG, "Create surface %#x.\n", surface_id);

    err = ff_hwframe_map_create(dst->hw_frames_ctx, dst, src,
                                &vaapi_unmap_from_drm,
                                (void*)(uintptr_t)surface_id);
    if (err < 0)
        return err;

    dst->width   = src->width;
    dst->height  = src->height;
    dst->data[3] = (uint8_t*)(uintptr_t)surface_id;

    av_log(dst_fc, AV_LOG_DEBUG, "Mapped DRM object %d to "
           "surface %#x.\n", desc->objects[0].fd, surface_id);

    return 0;
}

static void vaapi_unmap_to_drm(AVHWFramesContext *dst_fc,
                               HWMapDescriptor *hwmap)
{
    AVDRMFrameDescriptor *drm_desc = hwmap->priv;
    int i;

    for (i = 0; i < drm_desc->nb_objects; i++)
        close(drm_desc->objects[i].fd);

    av_freep(&drm_desc);
}

static int vaapi_map_to_drm(AVHWFramesContext *hwfc, AVFrame *dst,
                            const AVFrame *src, int flags)
{
#if CONFIG_VAAPI_1
    AVVAAPIDeviceContext *hwctx = hwfc->device_ctx->hwctx;
    VASurfaceID surface_id;
    VAStatus vas;
    VADRMPRIMESurfaceDescriptor va_desc;
    AVDRMFrameDescriptor *drm_desc = NULL;
    int err, i, j;

    surface_id = (VASurfaceID)(uintptr_t)src->data[3];

    vas = vaExportSurfaceHandle(hwctx->display, surface_id,
                                VA_SURFACE_ATTRIB_MEM_TYPE_DRM_PRIME_2,
                                VA_EXPORT_SURFACE_READ_ONLY |
                                VA_EXPORT_SURFACE_SEPARATE_LAYERS,
                                &va_desc);
    if (vas != VA_STATUS_SUCCESS) {
        if (vas == VA_STATUS_ERROR_UNIMPLEMENTED)
            return AVERROR(ENOSYS);
        av_log(hwfc, AV_LOG_ERROR, "Failed to export surface %#x: "
               "%d (%s).\n", surface_id, vas, vaErrorStr(vas));
        return AVERROR(EIO);
    }

    drm_desc = av_mallocz(sizeof(*drm_desc));
    if (!drm_desc) {
        err = AVERROR(ENOMEM);
        goto fail;
    }

    // By some bizarre coincidence, these structures are very similar...
    drm_desc->nb_objects = va_desc.num_objects;
    for (i = 0; i < va_desc.num_objects; i++) {
        drm_desc->objects[i].fd   = va_desc.objects[i].fd;
        drm_desc->objects[i].size = va_desc.objects[i].size;
        drm_desc->objects[i].format_modifier =
            va_desc.objects[i].drm_format_modifier;
    }
    drm_desc->nb_layers = va_desc.num_layers;
    for (i = 0; i < va_desc.num_layers; i++) {
        drm_desc->layers[i].format    = va_desc.layers[i].drm_format;
        drm_desc->layers[i].nb_planes = va_desc.layers[i].num_planes;
        for (j = 0; j < va_desc.layers[i].num_planes; j++) {
            drm_desc->layers[i].planes[j].object_index =
                va_desc.layers[i].object_index[j];
            drm_desc->layers[i].planes[j].offset =
                va_desc.layers[i].offset[j];
            drm_desc->layers[i].planes[j].pitch =
                va_desc.layers[i].pitch[j];
        }
    }

    err = ff_hwframe_map_create(src->hw_frames_ctx, dst, src,
                                &vaapi_unmap_to_drm, drm_desc);
    if (err < 0)
        goto fail;

    dst->width   = src->width;
    dst->height  = src->height;
    dst->data[0] = (uint8_t*)drm_desc;

    return 0;

fail:
    for (i = 0; i < va_desc.num_objects; i++)
        close(va_desc.objects[i].fd);
    av_freep(&drm_desc);
    return err;
#else
    // Older versions without vaExportSurfaceHandle() are not supported -
    // in theory this is possible with a combination of vaDeriveImage()
    // and vaAcquireBufferHandle(), but it doesn't carry enough metadata
    // to actually use the result in a generic way.
    return AVERROR(ENOSYS);
#endif
}
#endif

static int vaapi_map_to(AVHWFramesContext *hwfc, AVFrame *dst,
                        const AVFrame *src, int flags)
{
    switch (src->format) {
#if CONFIG_LIBDRM
    case AV_PIX_FMT_DRM_PRIME:
        return vaapi_map_from_drm(hwfc, dst, src, flags);
#endif
    default:
        return AVERROR(ENOSYS);
    }
}

static int vaapi_map_from(AVHWFramesContext *hwfc, AVFrame *dst,
                          const AVFrame *src, int flags)
{
    switch (dst->format) {
#if CONFIG_LIBDRM
    case AV_PIX_FMT_DRM_PRIME:
        return vaapi_map_to_drm(hwfc, dst, src, flags);
#endif
    default:
        return vaapi_map_to_memory(hwfc, dst, src, flags);
    }
}

static void vaapi_device_free(AVHWDeviceContext *ctx)
{
    AVVAAPIDeviceContext *hwctx = ctx->hwctx;
    VAAPIDevicePriv      *priv  = ctx->user_opaque;

    if (hwctx->display)
        vaTerminate(hwctx->display);

#if HAVE_VAAPI_X11
    if (priv->x11_display)
        XCloseDisplay(priv->x11_display);
#endif

    if (priv->drm_fd >= 0)
        close(priv->drm_fd);

    av_freep(&priv);
}

#if CONFIG_VAAPI_1
static void vaapi_device_log_error(void *context, const char *message)
{
    AVHWDeviceContext *ctx = context;

    av_log(ctx, AV_LOG_ERROR, "libva: %s", message);
}

static void vaapi_device_log_info(void *context, const char *message)
{
    AVHWDeviceContext *ctx = context;

    av_log(ctx, AV_LOG_VERBOSE, "libva: %s", message);
}
#endif

static int vaapi_device_connect(AVHWDeviceContext *ctx,
                                VADisplay display)
{
    AVVAAPIDeviceContext *hwctx = ctx->hwctx;
    int major, minor;
    VAStatus vas;

#if CONFIG_VAAPI_1
    vaSetErrorCallback(display, &vaapi_device_log_error, ctx);
    vaSetInfoCallback (display, &vaapi_device_log_info,  ctx);
#endif

    hwctx->display = display;

    vas = vaInitialize(display, &major, &minor);
    if (vas != VA_STATUS_SUCCESS) {
        av_log(ctx, AV_LOG_ERROR, "Failed to initialise VAAPI "
               "connection: %d (%s).\n", vas, vaErrorStr(vas));
        return AVERROR(EIO);
    }
    av_log(ctx, AV_LOG_VERBOSE, "Initialised VAAPI connection: "
           "version %d.%d\n", major, minor);

    return 0;
}

static int vaapi_device_create(AVHWDeviceContext *ctx, const char *device,
                               AVDictionary *opts, int flags)
{
    VAAPIDevicePriv *priv;
    VADisplay display = NULL;

    priv = av_mallocz(sizeof(*priv));
    if (!priv)
        return AVERROR(ENOMEM);

    priv->drm_fd = -1;

    ctx->user_opaque = priv;
    ctx->free        = vaapi_device_free;

#if HAVE_VAAPI_X11
    if (!display && !(device && device[0] == '/')) {
        // Try to open the device as an X11 display.
        priv->x11_display = XOpenDisplay(device);
        if (!priv->x11_display) {
            av_log(ctx, AV_LOG_VERBOSE, "Cannot open X11 display "
                   "%s.\n", XDisplayName(device));
        } else {
            display = vaGetDisplay(priv->x11_display);
            if (!display) {
                av_log(ctx, AV_LOG_ERROR, "Cannot open a VA display "
                       "from X11 display %s.\n", XDisplayName(device));
                return AVERROR_UNKNOWN;
            }

            av_log(ctx, AV_LOG_VERBOSE, "Opened VA display via "
                   "X11 display %s.\n", XDisplayName(device));
        }
    }
#endif

#if HAVE_VAAPI_DRM
    if (!display) {
        // Try to open the device as a DRM path.
        // Default to using the first render node if the user did not
        // supply a path.
        const char *path = device ? device : "/dev/dri/renderD128";
        priv->drm_fd = open(path, O_RDWR);
        if (priv->drm_fd < 0) {
            av_log(ctx, AV_LOG_VERBOSE, "Cannot open DRM device %s.\n",
                   path);
        } else {
            display = vaGetDisplayDRM(priv->drm_fd);
            if (!display) {
                av_log(ctx, AV_LOG_ERROR, "Cannot open a VA display "
                       "from DRM device %s.\n", path);
                return AVERROR_UNKNOWN;
            }

            av_log(ctx, AV_LOG_VERBOSE, "Opened VA display via "
                   "DRM device %s.\n", path);
        }
    }
#endif

    if (!display) {
        av_log(ctx, AV_LOG_ERROR, "No VA display found for "
               "device: %s.\n", device ? device : "");
        return AVERROR(EINVAL);
    }

    return vaapi_device_connect(ctx, display);
}

static int vaapi_device_derive(AVHWDeviceContext *ctx,
                               AVHWDeviceContext *src_ctx, int flags)
{
#if CONFIG_LIBDRM
    if (src_ctx->type == AV_HWDEVICE_TYPE_DRM) {
        AVDRMDeviceContext *src_hwctx = src_ctx->hwctx;
        VADisplay *display;
        VAAPIDevicePriv *priv;

        if (src_hwctx->fd < 0) {
            av_log(ctx, AV_LOG_ERROR, "DRM instance requires an associated "
                   "device to derive a VA display from.\n");
            return AVERROR(EINVAL);
        }

        priv = av_mallocz(sizeof(*priv));
        if (!priv)
            return AVERROR(ENOMEM);

        // Inherits the fd from the source context, which will close it.
        priv->drm_fd = -1;

        ctx->user_opaque = priv;
        ctx->free        = &vaapi_device_free;

        display = vaGetDisplayDRM(src_hwctx->fd);
        if (!display) {
            av_log(ctx, AV_LOG_ERROR, "Failed to open a VA display from "
                   "DRM device.\n");
            return AVERROR(EIO);
        }

        return vaapi_device_connect(ctx, display);
    }
#endif
    return AVERROR(ENOSYS);
}

const HWContextType ff_hwcontext_type_vaapi = {
    .type                   = AV_HWDEVICE_TYPE_VAAPI,
    .name                   = "VAAPI",

    .device_hwctx_size      = sizeof(AVVAAPIDeviceContext),
    .device_priv_size       = sizeof(VAAPIDeviceContext),
    .device_hwconfig_size   = sizeof(AVVAAPIHWConfig),
    .frames_hwctx_size      = sizeof(AVVAAPIFramesContext),
    .frames_priv_size       = sizeof(VAAPIFramesContext),

    .device_create          = &vaapi_device_create,
    .device_derive          = &vaapi_device_derive,
    .device_init            = &vaapi_device_init,
    .device_uninit          = &vaapi_device_uninit,
    .frames_get_constraints = &vaapi_frames_get_constraints,
    .frames_init            = &vaapi_frames_init,
    .frames_uninit          = &vaapi_frames_uninit,
    .frames_get_buffer      = &vaapi_get_buffer,
    .transfer_get_formats   = &vaapi_transfer_get_formats,
    .transfer_data_to       = &vaapi_transfer_data_to,
    .transfer_data_from     = &vaapi_transfer_data_from,
    .map_to                 = &vaapi_map_to,
    .map_from               = &vaapi_map_from,

    .pix_fmts = (const enum AVPixelFormat[]) {
        AV_PIX_FMT_VAAPI,
        AV_PIX_FMT_NONE
    },
};