summaryrefslogtreecommitdiff
path: root/gst/vaapiconvert/gstvaapiconvert.c
blob: acd2667dc693cac856df38b21bd17c59f97837ed (plain)
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
/*
 *  gstvaapiconvert.c - VA-API video converter
 *
 *  gstreamer-vaapi (C) 2010-2011 Splitted-Desktop Systems
 *
 *  This library 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.
 *
 *  This library 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 this library; if not, write to the Free
 *  Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 *  Boston, MA 02110-1301 USA
 */

/**
 * SECTION:gstvaapiconvert
 * @short_description: A VA-API based video pixels format converter
 *
 * vaapiconvert converts from raw YUV pixels to surfaces suitable for
 * the vaapisink element.
 */

#include "config.h"
#include <gst/gst.h>
#include <gst/video/video.h>
#include <gst/vaapi/gstvaapivideosink.h>
#include <gst/vaapi/gstvaapivideobuffer.h>
#include <gst/vaapi/gstvaapiutils_gst.h>
#include "gstvaapiconvert.h"

#define GST_PLUGIN_NAME "vaapiconvert"
#define GST_PLUGIN_DESC "A VA-API based video pixels format converter"

GST_DEBUG_CATEGORY_STATIC(gst_debug_vaapiconvert);
#define GST_CAT_DEFAULT gst_debug_vaapiconvert

/* ElementFactory information */
static const GstElementDetails gst_vaapiconvert_details =
    GST_ELEMENT_DETAILS(
        "VA-API colorspace converter",
        "Filter/Converter/Video",
        GST_PLUGIN_DESC,
        "Gwenole Beauchesne <gwenole.beauchesne@intel.com>");

/* Default templates */
static const char gst_vaapiconvert_yuv_caps_str[] =
    "video/x-raw-yuv, "
    "width  = (int) [ 1, MAX ], "
    "height = (int) [ 1, MAX ]; ";

static const char gst_vaapiconvert_vaapi_caps_str[] =
    GST_VAAPI_SURFACE_CAPS;

static GstStaticPadTemplate gst_vaapiconvert_sink_factory =
    GST_STATIC_PAD_TEMPLATE(
        "sink",
        GST_PAD_SINK,
        GST_PAD_ALWAYS,
        GST_STATIC_CAPS(gst_vaapiconvert_yuv_caps_str));

static GstStaticPadTemplate gst_vaapiconvert_src_factory =
    GST_STATIC_PAD_TEMPLATE(
        "src",
        GST_PAD_SRC,
        GST_PAD_ALWAYS,
        GST_STATIC_CAPS(gst_vaapiconvert_vaapi_caps_str));

GST_BOILERPLATE(
    GstVaapiConvert,
    gst_vaapiconvert,
    GstBaseTransform,
    GST_TYPE_BASE_TRANSFORM);

/*
 * Direct rendering levels (direct-rendering)
 * 0: upstream allocated YUV pixels
 * 1: vaapiconvert allocated YUV pixels (mapped from VA image)
 * 2: vaapiconvert allocated YUV pixels (mapped from VA surface)
 */
#define DIRECT_RENDERING_DEFAULT 2

enum {
    PROP_0,

    PROP_DIRECT_RENDERING,
};

static gboolean
gst_vaapiconvert_start(GstBaseTransform *trans);

static gboolean
gst_vaapiconvert_stop(GstBaseTransform *trans);

static GstFlowReturn
gst_vaapiconvert_transform(
    GstBaseTransform *trans,
    GstBuffer        *inbuf,
    GstBuffer        *outbuf
);

static GstCaps *
gst_vaapiconvert_transform_caps(
    GstBaseTransform *trans,
    GstPadDirection   direction,
    GstCaps          *caps
);

static gboolean
gst_vaapiconvert_set_caps(
    GstBaseTransform *trans,
    GstCaps          *incaps,
    GstCaps          *outcaps
);

static gboolean
gst_vaapiconvert_get_unit_size(
    GstBaseTransform *trans,
    GstCaps          *caps,
    guint            *size
);

static GstFlowReturn
gst_vaapiconvert_sinkpad_buffer_alloc(
    GstPad           *pad,
    guint64           offset,
    guint             size,
    GstCaps          *caps,
    GstBuffer       **pbuf
);

static GstFlowReturn
gst_vaapiconvert_prepare_output_buffer(
    GstBaseTransform *trans,
    GstBuffer        *inbuf,
    gint              size,
    GstCaps          *caps,
    GstBuffer       **poutbuf
);

static void
gst_vaapiconvert_destroy(GstVaapiConvert *convert)
{
    if (convert->images) {
        g_object_unref(convert->images);
        convert->images = NULL;
    }

    if (convert->surfaces) {
        g_object_unref(convert->surfaces);
        convert->surfaces = NULL;
    }

    if (convert->display) {
        g_object_unref(convert->display);
        convert->display = NULL;
    }
}

static void
gst_vaapiconvert_base_init(gpointer klass)
{
    GstElementClass * const element_class = GST_ELEMENT_CLASS(klass);

    gst_element_class_set_details(element_class, &gst_vaapiconvert_details);

    /* sink pad */
    gst_element_class_add_pad_template(
        element_class,
        gst_static_pad_template_get(&gst_vaapiconvert_sink_factory)
    );

    /* src pad */
    gst_element_class_add_pad_template(
        element_class,
        gst_static_pad_template_get(&gst_vaapiconvert_src_factory)
    );
}

static void
gst_vaapiconvert_finalize(GObject *object)
{
    gst_vaapiconvert_destroy(GST_VAAPICONVERT(object));

    G_OBJECT_CLASS(parent_class)->finalize(object);
}


static void
gst_vaapiconvert_set_property(
    GObject      *object,
    guint         prop_id,
    const GValue *value,
    GParamSpec   *pspec
)
{
    GstVaapiConvert * const convert = GST_VAAPICONVERT(object);

    switch (prop_id) {
    case PROP_DIRECT_RENDERING:
        GST_OBJECT_LOCK(convert);
        convert->direct_rendering = g_value_get_uint(value);
        GST_OBJECT_UNLOCK(convert);
        break;
    default:
        G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
        break;
    }
}

static void
gst_vaapiconvert_get_property(
    GObject    *object,
    guint       prop_id,
    GValue     *value,
    GParamSpec *pspec
)
{
    GstVaapiConvert * const convert = GST_VAAPICONVERT(object);

    switch (prop_id) {
    case PROP_DIRECT_RENDERING:
        g_value_set_uint(value, convert->direct_rendering);
        break;
    default:
        G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
        break;
    }
}

static void
gst_vaapiconvert_class_init(GstVaapiConvertClass *klass)
{
    GObjectClass * const object_class = G_OBJECT_CLASS(klass);
    GstBaseTransformClass * const trans_class = GST_BASE_TRANSFORM_CLASS(klass);

    object_class->finalize      = gst_vaapiconvert_finalize;
    object_class->set_property  = gst_vaapiconvert_set_property;
    object_class->get_property  = gst_vaapiconvert_get_property;

    trans_class->start          = gst_vaapiconvert_start;
    trans_class->stop           = gst_vaapiconvert_stop;
    trans_class->transform      = gst_vaapiconvert_transform;
    trans_class->transform_caps = gst_vaapiconvert_transform_caps;
    trans_class->set_caps       = gst_vaapiconvert_set_caps;
    trans_class->get_unit_size  = gst_vaapiconvert_get_unit_size;
    trans_class->prepare_output_buffer = gst_vaapiconvert_prepare_output_buffer;

    /**
     * GstVaapiConvert:direct-rendering:
     *
     * Selects the direct rendering level.
     * <orderedlist>
     * <listitem override="0">
     *   Disables direct rendering.
     * </listitem>
     * <listitem>
     *   Enables direct rendering to the output buffer. i.e. this
     *   tries to use a single buffer for both sink and src pads.
     * </listitem>
     * <listitem>
     *   Enables direct rendering to the underlying surface. i.e. with
     *   drivers supporting vaDeriveImage(), the output surface pixels
     *   will be modified directly.
     * </listitem>
     * </orderedlist>
     */
    g_object_class_install_property
        (object_class,
         PROP_DIRECT_RENDERING,
         g_param_spec_uint("direct-rendering",
                           "Direct rendering",
                           "Direct rendering level",
                           0, 2,
                           DIRECT_RENDERING_DEFAULT,
                           G_PARAM_READWRITE));
}

static void
gst_vaapiconvert_init(GstVaapiConvert *convert, GstVaapiConvertClass *klass)
{
    GstPad *sinkpad;

    convert->display                    = NULL;
    convert->images                     = NULL;
    convert->images_reset               = FALSE;
    convert->image_width                = 0;
    convert->image_height               = 0;
    convert->surfaces                   = NULL;
    convert->surfaces_reset             = FALSE;
    convert->surface_width              = 0;
    convert->surface_height             = 0;
    convert->direct_rendering_caps      = 0;
    convert->direct_rendering           = G_MAXUINT32;

    /* Override buffer allocator on sink pad */
    sinkpad = gst_element_get_static_pad(GST_ELEMENT(convert), "sink");
    gst_pad_set_bufferalloc_function(
        sinkpad,
        gst_vaapiconvert_sinkpad_buffer_alloc
    );
    g_object_unref(sinkpad);
}

static gboolean
gst_vaapiconvert_start(GstBaseTransform *trans)
{
    GstVaapiConvert * const convert = GST_VAAPICONVERT(trans);
    GstVaapiDisplay *display;

    /* Look for a downstream display */
    display = gst_vaapi_display_lookup_downstream(GST_ELEMENT(trans));
    if (!display)
        return FALSE;

    convert->display = g_object_ref(display);
    return TRUE;
}

static gboolean
gst_vaapiconvert_stop(GstBaseTransform *trans)
{
    GstVaapiConvert * const convert = GST_VAAPICONVERT(trans);

    if (convert->display) {
        g_object_unref(convert->display);
        convert->display = NULL;
    }
    return TRUE;
}

static GstFlowReturn
gst_vaapiconvert_transform(
    GstBaseTransform *trans,
    GstBuffer        *inbuf,
    GstBuffer        *outbuf
)
{
    GstVaapiConvert * const convert = GST_VAAPICONVERT(trans);
    GstVaapiVideoBuffer *vbuffer;
    GstVaapiSurface *surface;
    GstVaapiImage *image;
    gboolean success;

    vbuffer = GST_VAAPI_VIDEO_BUFFER(outbuf);
    surface = gst_vaapi_video_buffer_get_surface(vbuffer);
    if (!surface)
        return GST_FLOW_UNEXPECTED;

    if (convert->direct_rendering) {
        if (!GST_VAAPI_IS_VIDEO_BUFFER(inbuf)) {
            GST_DEBUG("GstVaapiVideoBuffer was expected");
            return GST_FLOW_UNEXPECTED;
        }

        vbuffer = GST_VAAPI_VIDEO_BUFFER(inbuf);
        image   = gst_vaapi_video_buffer_get_image(vbuffer);
        if (!image)
            return GST_FLOW_UNEXPECTED;
        if (!gst_vaapi_image_unmap(image))
            return GST_FLOW_UNEXPECTED;

        if (convert->direct_rendering < 2) {
            if (!gst_vaapi_surface_put_image(surface, image))
                goto error_put_image;
        }
        return GST_FLOW_OK;
    }

    image = gst_vaapi_video_pool_get_object(convert->images);
    if (!image)
        return GST_FLOW_UNEXPECTED;

    gst_vaapi_image_update_from_buffer(image, inbuf);
    success = gst_vaapi_surface_put_image(surface, image);
    gst_vaapi_video_pool_put_object(convert->images, image);
    if (!success)
        goto error_put_image;
    return GST_FLOW_OK;

error_put_image:
    {
        GST_WARNING("failed to upload %" GST_FOURCC_FORMAT " image "
                    "to surface 0x%08x",
                    GST_FOURCC_ARGS(gst_vaapi_image_get_format(image)),
                    gst_vaapi_surface_get_id(surface));
        return GST_FLOW_OK;
    }
}

static GstCaps *
gst_vaapiconvert_transform_caps(
    GstBaseTransform *trans,
    GstPadDirection   direction,
    GstCaps          *caps
)
{
    GstVaapiConvert * const convert = GST_VAAPICONVERT(trans);
    GstCaps *out_caps = NULL;
    GstStructure *structure;
    const GValue *v_width, *v_height, *v_framerate, *v_par;

    g_return_val_if_fail(GST_IS_CAPS(caps), NULL);

    structure   = gst_caps_get_structure(caps, 0);
    v_width     = gst_structure_get_value(structure, "width");
    v_height    = gst_structure_get_value(structure, "height");
    v_framerate = gst_structure_get_value(structure, "framerate");
    v_par       = gst_structure_get_value(structure, "pixel-aspect-ratio");

    if (!v_width || !v_height)
        return NULL;

    if (direction == GST_PAD_SINK) {
        if (!gst_structure_has_name(structure, "video/x-raw-yuv"))
            return NULL;
        out_caps = gst_caps_from_string(gst_vaapiconvert_vaapi_caps_str);
    }
    else {
        if (!gst_structure_has_name(structure, "video/x-vaapi-surface"))
            return NULL;
        out_caps = gst_caps_from_string(gst_vaapiconvert_yuv_caps_str);
        if (convert->display) {
            GstCaps *allowed_caps, *inter_caps;
            allowed_caps = gst_vaapi_display_get_image_caps(convert->display);
            if (!allowed_caps)
                return NULL;
            inter_caps = gst_caps_intersect(out_caps, allowed_caps);
            gst_caps_unref(allowed_caps);
            gst_caps_unref(out_caps);
            out_caps = inter_caps;
        }
    }

    structure = gst_caps_get_structure(out_caps, 0);
    gst_structure_set_value(structure, "width", v_width);
    gst_structure_set_value(structure, "height", v_height);
    if (v_framerate)
        gst_structure_set_value(structure, "framerate", v_framerate);
    if (v_par)
        gst_structure_set_value(structure, "pixel-aspect-ratio", v_par);
    return out_caps;
}

static gboolean
gst_vaapiconvert_ensure_image_pool(GstVaapiConvert *convert, GstCaps *caps)
{
    GstStructure * const structure = gst_caps_get_structure(caps, 0);
    gint width, height;

    gst_structure_get_int(structure, "width",  &width);
    gst_structure_get_int(structure, "height", &height);

    if (width != convert->image_width || height != convert->image_height) {
        convert->image_width  = width;
        convert->image_height = height;
        if (convert->images)
            g_object_unref(convert->images);
        convert->images = gst_vaapi_image_pool_new(convert->display, caps);
        if (!convert->images)
            return FALSE;
        convert->images_reset = TRUE;
    }
    return TRUE;
}

static gboolean
gst_vaapiconvert_ensure_surface_pool(GstVaapiConvert *convert, GstCaps *caps)
{
    GstStructure * const structure = gst_caps_get_structure(caps, 0);
    GstVaapiSurface *surface;
    GstVaapiImage *image;
    gint width, height;

    gst_structure_get_int(structure, "width",  &width);
    gst_structure_get_int(structure, "height", &height);

    if (width != convert->surface_width || height != convert->surface_height) {
        convert->surface_width  = width;
        convert->surface_height = height;
        if (convert->surfaces)
            g_object_unref(convert->surfaces);
        convert->surfaces = gst_vaapi_surface_pool_new(convert->display, caps);
        if (!convert->surfaces)
            return FALSE;
        convert->surfaces_reset = TRUE;
    }
    return TRUE;
}

static GstVaapiImageFormat
gst_video_format_to_vaapi_image_format(GstVideoFormat vformat)
{
    GstVaapiImageFormat vaformat;

    switch (vformat) {
    case GST_VIDEO_FORMAT_NV12: vaformat = GST_VAAPI_IMAGE_NV12; break;
    case GST_VIDEO_FORMAT_YV12: vaformat = GST_VAAPI_IMAGE_YV12; break;
    case GST_VIDEO_FORMAT_I420: vaformat = GST_VAAPI_IMAGE_I420; break;
    case GST_VIDEO_FORMAT_AYUV: vaformat = GST_VAAPI_IMAGE_AYUV; break;
    case GST_VIDEO_FORMAT_ARGB: vaformat = GST_VAAPI_IMAGE_ARGB; break;
    case GST_VIDEO_FORMAT_RGBA: vaformat = GST_VAAPI_IMAGE_RGBA; break;
    case GST_VIDEO_FORMAT_ABGR: vaformat = GST_VAAPI_IMAGE_ABGR; break;
    case GST_VIDEO_FORMAT_BGRA: vaformat = GST_VAAPI_IMAGE_BGRA; break;
    default:                    vaformat = (GstVaapiImageFormat)0; break;
    }
    return vaformat;
}

static void
gst_vaapiconvert_ensure_direct_rendering_caps(
    GstVaapiConvert *convert,
    GstCaps         *caps
)
{
    GstVaapiSurface *surface;
    GstVaapiImage *image;
    GstVaapiImageFormat vaformat;
    GstVideoFormat vformat;
    GstStructure *structure;
    gint width, height;

    if (!convert->images_reset && !convert->surfaces_reset)
        return;

    convert->images_reset          = FALSE;
    convert->surfaces_reset        = FALSE;
    convert->direct_rendering_caps = 0;

    structure = gst_caps_get_structure(caps, 0);
    if (!structure)
        return;
    gst_structure_get_int(structure, "width",  &width);
    gst_structure_get_int(structure, "height", &height);

    /* Translate from Gst video format to VA image format */
    if (!gst_video_format_parse_caps(caps, &vformat, NULL, NULL))
        return;
    if (!gst_video_format_is_yuv(vformat))
        return;
    vaformat = gst_video_format_to_vaapi_image_format(vformat);
    if (!vaformat)
        return;

    /* Check if we can alias sink & output buffers (same data_size) */
    image = gst_vaapi_video_pool_get_object(convert->images);
    if (image) {
        if (convert->direct_rendering_caps == 0 &&
            (gst_vaapi_image_get_format(image) == vaformat &&
             gst_vaapi_image_is_linear(image) &&
             (gst_vaapi_image_get_data_size(image) ==
              gst_video_format_get_size(vformat, width, height))))
            convert->direct_rendering_caps = 1;
        gst_vaapi_video_pool_put_object(convert->images, image);
    }

    /* Check if we can access to the surface pixels directly */
    surface = gst_vaapi_video_pool_get_object(convert->surfaces);
    if (surface) {
        image = gst_vaapi_surface_derive_image(surface);
        if (image) {
            if (gst_vaapi_image_map(image)) {
                if (convert->direct_rendering_caps == 1 &&
                    (gst_vaapi_image_get_format(image) == vaformat &&
                     gst_vaapi_image_is_linear(image) &&
                     (gst_vaapi_image_get_data_size(image) ==
                      gst_video_format_get_size(vformat, width, height))))
                    convert->direct_rendering_caps = 2;
                gst_vaapi_image_unmap(image);
            }
            g_object_unref(image);
        }
        gst_vaapi_video_pool_put_object(convert->surfaces, surface);
    }
}

static gboolean
gst_vaapiconvert_negotiate_buffers(
    GstVaapiConvert  *convert,
    GstCaps          *incaps,
    GstCaps          *outcaps
)
{
    guint dr;

    if (!gst_vaapiconvert_ensure_image_pool(convert, incaps))
        return FALSE;

    if (!gst_vaapiconvert_ensure_surface_pool(convert, outcaps))
        return FALSE;

    gst_vaapiconvert_ensure_direct_rendering_caps(convert, incaps);
    dr = MIN(convert->direct_rendering, convert->direct_rendering_caps);
    if (convert->direct_rendering != dr) {
        convert->direct_rendering = dr;
        GST_DEBUG("direct-rendering level: %d", dr);
    }
    return TRUE;
}

static gboolean
gst_vaapiconvert_set_caps(
    GstBaseTransform *trans,
    GstCaps          *incaps,
    GstCaps          *outcaps
)
{
    GstVaapiConvert * const convert = GST_VAAPICONVERT(trans);

    if (!gst_vaapiconvert_negotiate_buffers(convert, incaps, outcaps))
        return FALSE;

    return TRUE;
}

static gboolean
gst_vaapiconvert_get_unit_size(
    GstBaseTransform *trans,
    GstCaps          *caps,
    guint            *size
)
{
    GstStructure * const structure = gst_caps_get_structure(caps, 0);
    GstVideoFormat format;
    gint width, height;

    if (gst_structure_has_name(structure, "video/x-vaapi-surface"))
        *size = 0;
    else {
        if (!gst_video_format_parse_caps(caps, &format, &width, &height))
            return FALSE;
        *size = gst_video_format_get_size(format, width, height);
    }
    return TRUE;
}

static GstFlowReturn
gst_vaapiconvert_buffer_alloc(
    GstBaseTransform *trans,
    guint             size,
    GstCaps          *caps,
    GstBuffer       **pbuf
)
{
    GstVaapiConvert * const convert = GST_VAAPICONVERT(trans);
    GstBuffer *buffer = NULL;
    GstVaapiImage *image = NULL;
    GstVaapiSurface *surface = NULL;
    GstVaapiVideoBuffer *vbuffer;

    /* Check if we can use direct-rendering */
    if (!gst_vaapiconvert_negotiate_buffers(convert, caps, caps))
        goto error;
    if (!convert->direct_rendering)
        return GST_FLOW_OK;

    switch (convert->direct_rendering) {
    case 2:
        buffer  = gst_vaapi_video_buffer_new_from_pool(convert->surfaces);
        if (!buffer)
            goto error;
        vbuffer = GST_VAAPI_VIDEO_BUFFER(buffer);

        surface = gst_vaapi_video_buffer_get_surface(vbuffer);
        image   = gst_vaapi_surface_derive_image(surface);
        if (image && gst_vaapi_image_get_data_size(image) == size) {
            gst_vaapi_video_buffer_set_image(vbuffer, image);
            gst_object_unref(image); /* video buffer owns an extra reference */
            break;
        }

        /* We can't use the derive-image optimization. Disable it. */
        convert->direct_rendering = 1;
        gst_buffer_unref(buffer);
        buffer = NULL;

    case 1:
        buffer  = gst_vaapi_video_buffer_new_from_pool(convert->images);
        if (!buffer)
            goto error;
        vbuffer = GST_VAAPI_VIDEO_BUFFER(buffer);

        image   = gst_vaapi_video_buffer_get_image(vbuffer);
        break;
    }
    g_assert(image);

    if (!gst_vaapi_image_map(image))
        goto error;

    GST_BUFFER_DATA(buffer) = gst_vaapi_image_get_plane(image, 0);
    GST_BUFFER_SIZE(buffer) = gst_vaapi_image_get_data_size(image);

    gst_buffer_set_caps(buffer, caps);
    *pbuf = buffer;
    return GST_FLOW_OK;

error:
    /* We can't use the inout-buffers optimization. Disable it. */
    GST_DEBUG("disable in/out buffer optimization");
    if (buffer)
        gst_buffer_unref(buffer);
    convert->direct_rendering = 0;
    return GST_FLOW_OK;
}

static GstFlowReturn
gst_vaapiconvert_sinkpad_buffer_alloc(
    GstPad           *pad,
    guint64           offset,
    guint             size,
    GstCaps          *caps,
    GstBuffer       **pbuf
)
{
    GstBaseTransform *trans;
    GstFlowReturn ret;

    trans = GST_BASE_TRANSFORM(gst_pad_get_parent_element(pad));
    if (!trans)
        return GST_FLOW_UNEXPECTED;

    ret = gst_vaapiconvert_buffer_alloc(trans, size, caps, pbuf);
    g_object_unref(trans);
    return ret;
}

static GstFlowReturn
gst_vaapiconvert_prepare_output_buffer(
    GstBaseTransform *trans,
    GstBuffer        *inbuf,
    gint              size,
    GstCaps          *caps,
    GstBuffer       **poutbuf
)
{
    GstVaapiConvert * const convert = GST_VAAPICONVERT(trans);
    GstBuffer *buffer = NULL;
    GstFlowReturn ret;

    if (convert->direct_rendering == 2) {
        if (GST_VAAPI_IS_VIDEO_BUFFER(inbuf)) {
            buffer = gst_vaapi_video_buffer_new_from_buffer(inbuf);
            GST_BUFFER_SIZE(buffer) = size;
        }
        else {
            GST_DEBUG("upstream element destroyed our in/out buffer");
            convert->direct_rendering = 1;
        }
    }

    if (!buffer) {
        buffer = gst_vaapi_video_buffer_new_from_pool(convert->surfaces);
        if (!buffer)
            return GST_FLOW_UNEXPECTED;
    }

    gst_buffer_set_caps(buffer, caps);
    *poutbuf = buffer;
    return GST_FLOW_OK;
}

static gboolean
plugin_init(GstPlugin *plugin)
{
    GST_DEBUG_CATEGORY_INIT(gst_debug_vaapiconvert,
                            GST_PLUGIN_NAME, 0, GST_PLUGIN_DESC);

    return gst_element_register(plugin,
                                GST_PLUGIN_NAME,
                                GST_RANK_SECONDARY,
                                GST_TYPE_VAAPICONVERT);
}

GST_PLUGIN_DEFINE(
    GST_VERSION_MAJOR, GST_VERSION_MINOR,
    GST_PLUGIN_NAME,
    GST_PLUGIN_DESC,
    plugin_init,
    PACKAGE_VERSION,
    "GPL",
    PACKAGE,
    PACKAGE_BUGREPORT);