aboutsummaryrefslogtreecommitdiffstats
path: root/libavdevice/opengl_enc.c
blob: 851b94735d25930547d4da1296bd3c0e71b32262 (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
/*
 * Copyright (c) 2014 Lukasz Marek
 *
 * 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
 */

//TODO: support for more formats
//TODO: support for more systems.
//TODO: implement X11, Windows, Mac OS native default window. SDL 1.2 doesn't allow to render to custom thread.

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <stddef.h>

#include "config.h"

#if HAVE_WINDOWS_H
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#endif
#if HAVE_OPENGL_GL3_H
#include <OpenGL/gl3.h>
#elif HAVE_ES2_GL_H
#include <ES2/gl.h>
#else
#include <GL/gl.h>
#include <GL/glext.h>
#endif
#if HAVE_GLXGETPROCADDRESS
#include <GL/glx.h>
#endif

#if HAVE_SDL
#include <SDL.h>
#endif

#include "libavutil/common.h"
#include "libavutil/pixdesc.h"
#include "libavutil/log.h"
#include "libavutil/opt.h"
#include "libavutil/avassert.h"
#include "libavutil/avstring.h"
#include "libavformat/avformat.h"
#include "libavformat/internal.h"
#include "libavdevice/avdevice.h"
#include "opengl_enc_shaders.h"

#ifndef APIENTRY
#define APIENTRY
#endif

/* FF_GL_RED_COMPONENT is used for plannar pixel types.
 * Only red component is sampled in shaders.
 * On some platforms GL_RED is not available and GL_LUMINANCE have to be used,
 * but since OpenGL 3.0 GL_LUMINANCE is deprecated.
 * GL_RED produces RGBA = value, 0, 0, 1.
 * GL_LUMINANCE produces RGBA = value, value, value, 1.
 * Note: GL_INTENSITY may also be used which produce RGBA = value, value, value, value. */
#if defined(GL_RED)
#define FF_GL_RED_COMPONENT GL_RED
#elif defined(GL_LUMINANCE)
#define FF_GL_RED_COMPONENT GL_LUMINANCE
#else
#define FF_GL_RED_COMPONENT 0x1903; //GL_RED
#endif

/* Constants not defined for iOS */
#define FF_GL_UNSIGNED_BYTE_3_3_2 0x8032
#define FF_GL_UNSIGNED_BYTE_2_3_3_REV 0x8362
#define FF_GL_UNSIGNED_SHORT_1_5_5_5_REV 0x8366
#define FF_GL_UNPACK_ROW_LENGTH          0x0CF2

/* MinGW exposes only OpenGL 1.1 API */
#define FF_GL_ARRAY_BUFFER                0x8892
#define FF_GL_ELEMENT_ARRAY_BUFFER        0x8893
#define FF_GL_STATIC_DRAW                 0x88E4
#define FF_GL_FRAGMENT_SHADER             0x8B30
#define FF_GL_VERTEX_SHADER               0x8B31
#define FF_GL_COMPILE_STATUS              0x8B81
#define FF_GL_LINK_STATUS                 0x8B82
#define FF_GL_INFO_LOG_LENGTH             0x8B84
typedef void   (APIENTRY *FF_PFNGLACTIVETEXTUREPROC) (GLenum texture);
typedef void   (APIENTRY *FF_PFNGLGENBUFFERSPROC) (GLsizei n, GLuint *buffers);
typedef void   (APIENTRY *FF_PFNGLDELETEBUFFERSPROC) (GLsizei n, const GLuint *buffers);
typedef void   (APIENTRY *FF_PFNGLBUFFERDATAPROC) (GLenum target, ptrdiff_t size, const GLvoid *data, GLenum usage);
typedef void   (APIENTRY *FF_PFNGLBINDBUFFERPROC) (GLenum target, GLuint buffer);
typedef GLint  (APIENTRY *FF_PFNGLGETATTRIBLOCATIONPROC) (GLuint program, const char *name);
typedef void   (APIENTRY *FF_PFNGLENABLEVERTEXATTRIBARRAYPROC) (GLuint index);
typedef void   (APIENTRY *FF_PFNGLVERTEXATTRIBPOINTERPROC) (GLuint index, GLint size, GLenum type, GLboolean normalized, GLsizei stride, uintptr_t pointer);
typedef GLint  (APIENTRY *FF_PFNGLGETUNIFORMLOCATIONPROC) (GLuint program, const char *name);
typedef void   (APIENTRY *FF_PFNGLUNIFORM1FPROC) (GLint location, GLfloat v0);
typedef void   (APIENTRY *FF_PFNGLUNIFORM1IPROC) (GLint location, GLint v0);
typedef void   (APIENTRY *FF_PFNGLUNIFORMMATRIX4FVPROC) (GLint location, GLsizei count, GLboolean transpose, const GLfloat *value);
typedef GLuint (APIENTRY *FF_PFNGLCREATEPROGRAMPROC) (void);
typedef void   (APIENTRY *FF_PFNGLDELETEPROGRAMPROC) (GLuint program);
typedef void   (APIENTRY *FF_PFNGLUSEPROGRAMPROC) (GLuint program);
typedef void   (APIENTRY *FF_PFNGLLINKPROGRAMPROC) (GLuint program);
typedef void   (APIENTRY *FF_PFNGLGETPROGRAMIVPROC) (GLuint program, GLenum pname, GLint *params);
typedef void   (APIENTRY *FF_PFNGLGETPROGRAMINFOLOGPROC) (GLuint program, GLsizei bufSize, GLsizei *length, char *infoLog);
typedef void   (APIENTRY *FF_PFNGLATTACHSHADERPROC) (GLuint program, GLuint shader);
typedef GLuint (APIENTRY *FF_PFNGLCREATESHADERPROC) (GLenum type);
typedef void   (APIENTRY *FF_PFNGLDELETESHADERPROC) (GLuint shader);
typedef void   (APIENTRY *FF_PFNGLCOMPILESHADERPROC) (GLuint shader);
typedef void   (APIENTRY *FF_PFNGLSHADERSOURCEPROC) (GLuint shader, GLsizei count, const char* *string, const GLint *length);
typedef void   (APIENTRY *FF_PFNGLGETSHADERIVPROC) (GLuint shader, GLenum pname, GLint *params);
typedef void   (APIENTRY *FF_PFNGLGETSHADERINFOLOGPROC) (GLuint shader, GLsizei bufSize, GLsizei *length, char *infoLog);

typedef struct FFOpenGLFunctions {
    FF_PFNGLACTIVETEXTUREPROC glActiveTexture;                     //Require GL ARB multitexture
    FF_PFNGLGENBUFFERSPROC glGenBuffers;                           //Require GL_ARB_vertex_buffer_object
    FF_PFNGLDELETEBUFFERSPROC glDeleteBuffers;                     //Require GL_ARB_vertex_buffer_object
    FF_PFNGLBUFFERDATAPROC glBufferData;                           //Require GL_ARB_vertex_buffer_object
    FF_PFNGLBINDBUFFERPROC glBindBuffer;                           //Require GL_ARB_vertex_buffer_object
    FF_PFNGLGETATTRIBLOCATIONPROC glGetAttribLocation;             //Require GL_ARB_vertex_shader
    FF_PFNGLENABLEVERTEXATTRIBARRAYPROC glEnableVertexAttribArray; //Require GL_ARB_vertex_shader
    FF_PFNGLVERTEXATTRIBPOINTERPROC glVertexAttribPointer;         //Require GL_ARB_vertex_shader
    FF_PFNGLGETUNIFORMLOCATIONPROC glGetUniformLocation;           //Require GL_ARB_shader_objects
    FF_PFNGLUNIFORM1FPROC glUniform1f;                             //Require GL_ARB_shader_objects
    FF_PFNGLUNIFORM1IPROC glUniform1i;                             //Require GL_ARB_shader_objects
    FF_PFNGLUNIFORMMATRIX4FVPROC glUniformMatrix4fv;               //Require GL_ARB_shader_objects
    FF_PFNGLCREATEPROGRAMPROC glCreateProgram;                     //Require GL_ARB_shader_objects
    FF_PFNGLDELETEPROGRAMPROC glDeleteProgram;                     //Require GL_ARB_shader_objects
    FF_PFNGLUSEPROGRAMPROC glUseProgram;                           //Require GL_ARB_shader_objects
    FF_PFNGLLINKPROGRAMPROC glLinkProgram;                         //Require GL_ARB_shader_objects
    FF_PFNGLGETPROGRAMIVPROC glGetProgramiv;                       //Require GL_ARB_shader_objects
    FF_PFNGLGETPROGRAMINFOLOGPROC glGetProgramInfoLog;             //Require GL_ARB_shader_objects
    FF_PFNGLATTACHSHADERPROC glAttachShader;                       //Require GL_ARB_shader_objects
    FF_PFNGLCREATESHADERPROC glCreateShader;                       //Require GL_ARB_shader_objects
    FF_PFNGLDELETESHADERPROC glDeleteShader;                       //Require GL_ARB_shader_objects
    FF_PFNGLCOMPILESHADERPROC glCompileShader;                     //Require GL_ARB_shader_objects
    FF_PFNGLSHADERSOURCEPROC glShaderSource;                       //Require GL_ARB_shader_objects
    FF_PFNGLGETSHADERIVPROC glGetShaderiv;                         //Require GL_ARB_shader_objects
    FF_PFNGLGETSHADERINFOLOGPROC glGetShaderInfoLog;               //Require GL_ARB_shader_objects
} FFOpenGLFunctions;

#define OPENGL_ERROR_CHECK(ctx) \
{\
    GLenum err_code; \
    if ((err_code = glGetError()) != GL_NO_ERROR) { \
        av_log(ctx, AV_LOG_ERROR, "OpenGL error occurred in '%s', line %d: %d\n", __FUNCTION__, __LINE__, err_code); \
        goto fail; \
    } \
}\

typedef struct OpenGLVertexInfo
{
    float x, y, z;    ///<Position
    float s0, t0;     ///<Texture coords
} OpenGLVertexInfo;

/* defines 2 triangles to display */
static const GLushort g_index[6] =
{
    0, 1, 2,
    0, 3, 2,
};

typedef struct OpenGLContext {
    AVClass *class;                    ///< class for private options

#if HAVE_SDL
    SDL_Surface *surface;
#endif
    FFOpenGLFunctions glprocs;

    int inited;                        ///< Set to 1 when write_header was successfully called.
    uint8_t background[4];             ///< Background color
    int no_window;                     ///< 0 for create default window
    char *window_title;                ///< Title of the window

    /* OpenGL implementation limits */
    GLint max_texture_size;            ///< Maximum texture size
    GLint max_viewport_width;          ///< Maximum viewport size
    GLint max_viewport_height;         ///< Maximum viewport size
    int non_pow_2_textures;            ///< 1 when non power of 2 textures are supported
    int unpack_subimage;               ///< 1 when GL_EXT_unpack_subimage is available

    /* Current OpenGL configuration */
    GLuint program;                    ///< Shader program
    GLuint vertex_shader;              ///< Vertex shader
    GLuint fragment_shader;            ///< Fragment shader for current pix_pmt
    GLuint texture_name[4];            ///< Textures' IDs
    GLuint index_buffer;               ///< Index buffer
    GLuint vertex_buffer;              ///< Vertex buffer
    OpenGLVertexInfo vertex[4];        ///< VBO
    GLint projection_matrix_location;  ///< Uniforms' locations
    GLint model_view_matrix_location;
    GLint color_map_location;
    GLint chroma_div_w_location;
    GLint chroma_div_h_location;
    GLint texture_location[4];
    GLint position_attrib;             ///< Attibutes' locations
    GLint texture_coords_attrib;

    GLfloat projection_matrix[16];     ///< Projection matrix
    GLfloat model_view_matrix[16];     ///< Modev view matrix
    GLfloat color_map[16];             ///< RGBA color map matrix
    GLfloat chroma_div_w;              ///< Chroma subsampling w ratio
    GLfloat chroma_div_h;              ///< Chroma subsampling h ratio

    /* Stream information */
    GLenum format;
    GLenum type;
    int width;                         ///< Stream width
    int height;                        ///< Stream height
    enum AVPixelFormat pix_fmt;        ///< Stream pixel format
    int picture_width;                 ///< Rendered width
    int picture_height;                ///< Rendered height
    int window_width;
    int window_height;
} OpenGLContext;

static const struct OpenGLFormatDesc {
    enum AVPixelFormat fixel_format;
    const char * const * fragment_shader;
    GLenum format;
    GLenum type;
} opengl_format_desc[] = {
    { AV_PIX_FMT_YUV420P,    &FF_OPENGL_FRAGMENT_SHADER_YUV_PLANAR,  FF_GL_RED_COMPONENT, GL_UNSIGNED_BYTE },
    { AV_PIX_FMT_YUV444P,    &FF_OPENGL_FRAGMENT_SHADER_YUV_PLANAR,  FF_GL_RED_COMPONENT, GL_UNSIGNED_BYTE },
    { AV_PIX_FMT_YUV422P,    &FF_OPENGL_FRAGMENT_SHADER_YUV_PLANAR,  FF_GL_RED_COMPONENT, GL_UNSIGNED_BYTE },
    { AV_PIX_FMT_YUV410P,    &FF_OPENGL_FRAGMENT_SHADER_YUV_PLANAR,  FF_GL_RED_COMPONENT, GL_UNSIGNED_BYTE },
    { AV_PIX_FMT_YUV411P,    &FF_OPENGL_FRAGMENT_SHADER_YUV_PLANAR,  FF_GL_RED_COMPONENT, GL_UNSIGNED_BYTE },
    { AV_PIX_FMT_YUV440P,    &FF_OPENGL_FRAGMENT_SHADER_YUV_PLANAR,  FF_GL_RED_COMPONENT, GL_UNSIGNED_BYTE },
    { AV_PIX_FMT_YUV420P16,  &FF_OPENGL_FRAGMENT_SHADER_YUV_PLANAR,  FF_GL_RED_COMPONENT, GL_UNSIGNED_SHORT },
    { AV_PIX_FMT_YUV422P16,  &FF_OPENGL_FRAGMENT_SHADER_YUV_PLANAR,  FF_GL_RED_COMPONENT, GL_UNSIGNED_SHORT },
    { AV_PIX_FMT_YUV444P16,  &FF_OPENGL_FRAGMENT_SHADER_YUV_PLANAR,  FF_GL_RED_COMPONENT, GL_UNSIGNED_SHORT },
    { AV_PIX_FMT_YUVA420P,   &FF_OPENGL_FRAGMENT_SHADER_YUVA_PLANAR, FF_GL_RED_COMPONENT, GL_UNSIGNED_BYTE },
    { AV_PIX_FMT_YUVA444P,   &FF_OPENGL_FRAGMENT_SHADER_YUVA_PLANAR, FF_GL_RED_COMPONENT, GL_UNSIGNED_BYTE },
    { AV_PIX_FMT_YUVA422P,   &FF_OPENGL_FRAGMENT_SHADER_YUVA_PLANAR, FF_GL_RED_COMPONENT, GL_UNSIGNED_BYTE },
    { AV_PIX_FMT_YUVA420P16, &FF_OPENGL_FRAGMENT_SHADER_YUVA_PLANAR, FF_GL_RED_COMPONENT, GL_UNSIGNED_SHORT },
    { AV_PIX_FMT_YUVA422P16, &FF_OPENGL_FRAGMENT_SHADER_YUVA_PLANAR, FF_GL_RED_COMPONENT, GL_UNSIGNED_SHORT },
    { AV_PIX_FMT_YUVA444P16, &FF_OPENGL_FRAGMENT_SHADER_YUVA_PLANAR, FF_GL_RED_COMPONENT, GL_UNSIGNED_SHORT },
    { AV_PIX_FMT_RGB24,      &FF_OPENGL_FRAGMENT_SHADER_RGB_PACKET,  GL_RGB, GL_UNSIGNED_BYTE },
    { AV_PIX_FMT_BGR24,      &FF_OPENGL_FRAGMENT_SHADER_RGB_PACKET,  GL_RGB, GL_UNSIGNED_BYTE },
    { AV_PIX_FMT_0RGB,       &FF_OPENGL_FRAGMENT_SHADER_RGB_PACKET,  GL_RGBA, GL_UNSIGNED_BYTE },
    { AV_PIX_FMT_RGB0,       &FF_OPENGL_FRAGMENT_SHADER_RGB_PACKET,  GL_RGBA, GL_UNSIGNED_BYTE },
    { AV_PIX_FMT_0BGR,       &FF_OPENGL_FRAGMENT_SHADER_RGB_PACKET,  GL_RGBA, GL_UNSIGNED_BYTE },
    { AV_PIX_FMT_BGR0,       &FF_OPENGL_FRAGMENT_SHADER_RGB_PACKET,  GL_RGBA, GL_UNSIGNED_BYTE },
    { AV_PIX_FMT_RGB565,     &FF_OPENGL_FRAGMENT_SHADER_RGB_PACKET,  GL_RGB, GL_UNSIGNED_SHORT_5_6_5 },
    { AV_PIX_FMT_BGR565,     &FF_OPENGL_FRAGMENT_SHADER_RGB_PACKET,  GL_RGB, GL_UNSIGNED_SHORT_5_6_5 },
    { AV_PIX_FMT_RGB555,     &FF_OPENGL_FRAGMENT_SHADER_RGB_PACKET,  GL_RGBA, FF_GL_UNSIGNED_SHORT_1_5_5_5_REV },
    { AV_PIX_FMT_BGR555,     &FF_OPENGL_FRAGMENT_SHADER_RGB_PACKET,  GL_RGBA, FF_GL_UNSIGNED_SHORT_1_5_5_5_REV },
    { AV_PIX_FMT_RGB8,       &FF_OPENGL_FRAGMENT_SHADER_RGB_PACKET,  GL_RGB, FF_GL_UNSIGNED_BYTE_3_3_2 },
    { AV_PIX_FMT_BGR8,       &FF_OPENGL_FRAGMENT_SHADER_RGB_PACKET,  GL_RGB, FF_GL_UNSIGNED_BYTE_2_3_3_REV },
    { AV_PIX_FMT_RGB48,      &FF_OPENGL_FRAGMENT_SHADER_RGB_PACKET,  GL_RGB, GL_UNSIGNED_SHORT },
    { AV_PIX_FMT_ARGB,       &FF_OPENGL_FRAGMENT_SHADER_RGBA_PACKET, GL_RGBA, GL_UNSIGNED_BYTE },
    { AV_PIX_FMT_RGBA,       &FF_OPENGL_FRAGMENT_SHADER_RGBA_PACKET, GL_RGBA, GL_UNSIGNED_BYTE },
    { AV_PIX_FMT_ABGR,       &FF_OPENGL_FRAGMENT_SHADER_RGBA_PACKET, GL_RGBA, GL_UNSIGNED_BYTE },
    { AV_PIX_FMT_BGRA,       &FF_OPENGL_FRAGMENT_SHADER_RGBA_PACKET, GL_RGBA, GL_UNSIGNED_BYTE },
    { AV_PIX_FMT_RGBA64,     &FF_OPENGL_FRAGMENT_SHADER_RGBA_PACKET, GL_RGBA, GL_UNSIGNED_SHORT },
    { AV_PIX_FMT_BGRA64,     &FF_OPENGL_FRAGMENT_SHADER_RGBA_PACKET, GL_RGBA, GL_UNSIGNED_SHORT },
    { AV_PIX_FMT_GBRP,       &FF_OPENGL_FRAGMENT_SHADER_RGB_PLANAR,  FF_GL_RED_COMPONENT, GL_UNSIGNED_BYTE },
    { AV_PIX_FMT_GBRP16,     &FF_OPENGL_FRAGMENT_SHADER_RGB_PLANAR,  FF_GL_RED_COMPONENT, GL_UNSIGNED_SHORT },
    { AV_PIX_FMT_GBRAP,      &FF_OPENGL_FRAGMENT_SHADER_RGBA_PLANAR, FF_GL_RED_COMPONENT, GL_UNSIGNED_BYTE },
    { AV_PIX_FMT_GBRAP16,    &FF_OPENGL_FRAGMENT_SHADER_RGBA_PLANAR, FF_GL_RED_COMPONENT, GL_UNSIGNED_SHORT },
    { AV_PIX_FMT_GRAY8,      &FF_OPENGL_FRAGMENT_SHADER_GRAY,        FF_GL_RED_COMPONENT, GL_UNSIGNED_BYTE },
    { AV_PIX_FMT_GRAY16,     &FF_OPENGL_FRAGMENT_SHADER_GRAY,        FF_GL_RED_COMPONENT, GL_UNSIGNED_SHORT },
    { AV_PIX_FMT_NONE,       NULL }
};

static av_cold int opengl_prepare_vertex(AVFormatContext *s);
static int opengl_draw(AVFormatContext *h, void *intput, int repaint, int is_pkt);
static av_cold int opengl_init_context(OpenGLContext *opengl);

static av_cold void opengl_deinit_context(OpenGLContext *opengl)
{
    glDeleteTextures(4, opengl->texture_name);
    opengl->texture_name[0] = opengl->texture_name[1] =
    opengl->texture_name[2] = opengl->texture_name[3] = 0;
    if (opengl->glprocs.glUseProgram)
        opengl->glprocs.glUseProgram(0);
    if (opengl->glprocs.glDeleteProgram) {
        opengl->glprocs.glDeleteProgram(opengl->program);
        opengl->program = 0;
    }
    if (opengl->glprocs.glDeleteShader) {
        opengl->glprocs.glDeleteShader(opengl->vertex_shader);
        opengl->glprocs.glDeleteShader(opengl->fragment_shader);
        opengl->vertex_shader = opengl->fragment_shader = 0;
    }
    if (opengl->glprocs.glBindBuffer) {
        opengl->glprocs.glBindBuffer(FF_GL_ARRAY_BUFFER, 0);
        opengl->glprocs.glBindBuffer(FF_GL_ELEMENT_ARRAY_BUFFER, 0);
    }
    if (opengl->glprocs.glDeleteBuffers) {
        opengl->glprocs.glDeleteBuffers(2, &opengl->index_buffer);
        opengl->vertex_buffer = opengl->index_buffer = 0;
    }
}

static int opengl_resize(AVFormatContext *h, int width, int height)
{
    int ret = 0;
    OpenGLContext *opengl = h->priv_data;
    opengl->window_width = width;
    opengl->window_height = height;
    if (opengl->inited) {
        if (opengl->no_window &&
            (ret = avdevice_dev_to_app_control_message(h, AV_DEV_TO_APP_PREPARE_WINDOW_BUFFER, NULL , 0)) < 0) {
            av_log(opengl, AV_LOG_ERROR, "Application failed to prepare window buffer.\n");
            goto end;
        }
        if ((ret = opengl_prepare_vertex(h)) < 0)
            goto end;
        ret = opengl_draw(h, NULL, 1, 0);
    }
  end:
    return ret;
}

static int opengl_control_message(AVFormatContext *h, int type, void *data, size_t data_size)
{
    OpenGLContext *opengl = h->priv_data;
    switch(type) {
    case AV_APP_TO_DEV_WINDOW_SIZE:
        if (data) {
            AVDeviceRect *message = data;
            return opengl_resize(h, message->width, message->height);
        }
        return AVERROR(EINVAL);
    case AV_APP_TO_DEV_WINDOW_REPAINT:
        return opengl_resize(h, opengl->window_width, opengl->window_height);
    }
    return AVERROR(ENOSYS);
}

#if HAVE_SDL
static int opengl_sdl_recreate_window(OpenGLContext *opengl, int width, int height)
{
    opengl->surface = SDL_SetVideoMode(width, height,
                                       32, SDL_OPENGL | SDL_RESIZABLE);
    if (!opengl->surface) {
        av_log(opengl, AV_LOG_ERROR, "Unable to set video mode: %s\n", SDL_GetError());
        return AVERROR_EXTERNAL;
    }
    SDL_GL_SetAttribute(SDL_GL_RED_SIZE, 8);
    SDL_GL_SetAttribute(SDL_GL_GREEN_SIZE, 8);
    SDL_GL_SetAttribute(SDL_GL_BLUE_SIZE, 8);
    SDL_GL_SetAttribute(SDL_GL_ALPHA_SIZE, 8);
    SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
    return 0;
}

static int opengl_sdl_process_events(AVFormatContext *h)
{
    int ret;
    OpenGLContext *opengl = h->priv_data;
    SDL_Event event;
    SDL_PumpEvents();
    while (SDL_PeepEvents(&event, 1, SDL_GETEVENT, SDL_ALLEVENTS) > 0) {
        switch (event.type) {
        case SDL_QUIT:
            return AVERROR(EIO);
        case SDL_KEYDOWN:
            switch (event.key.keysym.sym) {
            case SDLK_ESCAPE:
            case SDLK_q:
                return AVERROR(EIO);
            }
            return 0;
        case SDL_VIDEORESIZE: {
            char buffer[100];
            int reinit;
            AVDeviceRect message;
            /* clean up old context because SDL_SetVideoMode may lose its state. */
            SDL_VideoDriverName(buffer, sizeof(buffer));
            reinit = !av_strncasecmp(buffer, "quartz", sizeof(buffer));
            if (reinit) {
                opengl_deinit_context(opengl);
            }
            if ((ret = opengl_sdl_recreate_window(opengl, event.resize.w, event.resize.h)) < 0)
                return ret;
            if (reinit && (ret = opengl_init_context(opengl)) < 0)
                return ret;
            message.width = opengl->surface->w;
            message.height = opengl->surface->h;
            return opengl_control_message(h, AV_APP_TO_DEV_WINDOW_SIZE, &message, sizeof(AVDeviceRect));
            }
        }
    }
    return 0;
}

static int av_cold opengl_sdl_create_window(AVFormatContext *h)
{
    int ret;
    char buffer[100];
    OpenGLContext *opengl = h->priv_data;
    AVDeviceRect message;
    if (SDL_Init(SDL_INIT_VIDEO)) {
        av_log(opengl, AV_LOG_ERROR, "Unable to initialize SDL: %s\n", SDL_GetError());
        return AVERROR_EXTERNAL;
    }
    if ((ret = opengl_sdl_recreate_window(opengl, opengl->window_width,
                                          opengl->window_height)) < 0)
        return ret;
    av_log(opengl, AV_LOG_INFO, "SDL driver: '%s'.\n", SDL_VideoDriverName(buffer, sizeof(buffer)));
    message.width = opengl->surface->w;
    message.height = opengl->surface->h;
    SDL_WM_SetCaption(opengl->window_title, NULL);
    opengl_control_message(h, AV_APP_TO_DEV_WINDOW_SIZE, &message, sizeof(AVDeviceRect));
    return 0;
}

static int av_cold opengl_sdl_load_procedures(OpenGLContext *opengl)
{
    FFOpenGLFunctions *procs = &opengl->glprocs;

#define LOAD_OPENGL_FUN(name, type) \
    procs->name = (type)SDL_GL_GetProcAddress(#name); \
    if (!procs->name) { \
        av_log(opengl, AV_LOG_ERROR, "Cannot load OpenGL function: '%s'\n", #name); \
        return AVERROR(ENOSYS); \
    }

    LOAD_OPENGL_FUN(glActiveTexture, FF_PFNGLACTIVETEXTUREPROC)
    LOAD_OPENGL_FUN(glGenBuffers, FF_PFNGLGENBUFFERSPROC)
    LOAD_OPENGL_FUN(glDeleteBuffers, FF_PFNGLDELETEBUFFERSPROC)
    LOAD_OPENGL_FUN(glBufferData, FF_PFNGLBUFFERDATAPROC)
    LOAD_OPENGL_FUN(glBindBuffer, FF_PFNGLBINDBUFFERPROC)
    LOAD_OPENGL_FUN(glGetAttribLocation, FF_PFNGLGETATTRIBLOCATIONPROC)
    LOAD_OPENGL_FUN(glGetUniformLocation, FF_PFNGLGETUNIFORMLOCATIONPROC)
    LOAD_OPENGL_FUN(glUniform1f, FF_PFNGLUNIFORM1FPROC)
    LOAD_OPENGL_FUN(glUniform1i, FF_PFNGLUNIFORM1IPROC)
    LOAD_OPENGL_FUN(glUniformMatrix4fv, FF_PFNGLUNIFORMMATRIX4FVPROC)
    LOAD_OPENGL_FUN(glCreateProgram, FF_PFNGLCREATEPROGRAMPROC)
    LOAD_OPENGL_FUN(glDeleteProgram, FF_PFNGLDELETEPROGRAMPROC)
    LOAD_OPENGL_FUN(glUseProgram, FF_PFNGLUSEPROGRAMPROC)
    LOAD_OPENGL_FUN(glLinkProgram, FF_PFNGLLINKPROGRAMPROC)
    LOAD_OPENGL_FUN(glGetProgramiv, FF_PFNGLGETPROGRAMIVPROC)
    LOAD_OPENGL_FUN(glGetProgramInfoLog, FF_PFNGLGETPROGRAMINFOLOGPROC)
    LOAD_OPENGL_FUN(glAttachShader, FF_PFNGLATTACHSHADERPROC)
    LOAD_OPENGL_FUN(glCreateShader, FF_PFNGLCREATESHADERPROC)
    LOAD_OPENGL_FUN(glDeleteShader, FF_PFNGLDELETESHADERPROC)
    LOAD_OPENGL_FUN(glCompileShader, FF_PFNGLCOMPILESHADERPROC)
    LOAD_OPENGL_FUN(glShaderSource, FF_PFNGLSHADERSOURCEPROC)
    LOAD_OPENGL_FUN(glGetShaderiv, FF_PFNGLGETSHADERIVPROC)
    LOAD_OPENGL_FUN(glGetShaderInfoLog, FF_PFNGLGETSHADERINFOLOGPROC)
    LOAD_OPENGL_FUN(glEnableVertexAttribArray, FF_PFNGLENABLEVERTEXATTRIBARRAYPROC)
    LOAD_OPENGL_FUN(glVertexAttribPointer, FF_PFNGLVERTEXATTRIBPOINTERPROC)

    return 0;

#undef LOAD_OPENGL_FUN
}
#endif /* HAVE_SDL */

#if defined(__APPLE__)
static int av_cold opengl_load_procedures(OpenGLContext *opengl)
{
    FFOpenGLFunctions *procs = &opengl->glprocs;

#if HAVE_SDL
    if (!opengl->no_window)
        return opengl_sdl_load_procedures(opengl);
#endif

    procs->glActiveTexture = glActiveTexture;
    procs->glGenBuffers = glGenBuffers;
    procs->glDeleteBuffers = glDeleteBuffers;
    procs->glBufferData = glBufferData;
    procs->glBindBuffer = glBindBuffer;
    procs->glGetAttribLocation = glGetAttribLocation;
    procs->glGetUniformLocation = glGetUniformLocation;
    procs->glUniform1f = glUniform1f;
    procs->glUniform1i = glUniform1i;
    procs->glUniformMatrix4fv = glUniformMatrix4fv;
    procs->glCreateProgram = glCreateProgram;
    procs->glDeleteProgram = glDeleteProgram;
    procs->glUseProgram = glUseProgram;
    procs->glLinkProgram = glLinkProgram;
    procs->glGetProgramiv = glGetProgramiv;
    procs->glGetProgramInfoLog = glGetProgramInfoLog;
    procs->glAttachShader = glAttachShader;
    procs->glCreateShader = glCreateShader;
    procs->glDeleteShader = glDeleteShader;
    procs->glCompileShader = glCompileShader;
    procs->glShaderSource = glShaderSource;
    procs->glGetShaderiv = glGetShaderiv;
    procs->glGetShaderInfoLog = glGetShaderInfoLog;
    procs->glEnableVertexAttribArray = glEnableVertexAttribArray;
    procs->glVertexAttribPointer = (FF_PFNGLVERTEXATTRIBPOINTERPROC) glVertexAttribPointer;
    return 0;
}
#else
static int av_cold opengl_load_procedures(OpenGLContext *opengl)
{
    FFOpenGLFunctions *procs = &opengl->glprocs;

#if HAVE_GLXGETPROCADDRESS
#define SelectedGetProcAddress glXGetProcAddress
#elif HAVE_WGLGETPROCADDRESS
#define SelectedGetProcAddress wglGetProcAddress
#endif

#define LOAD_OPENGL_FUN(name, type) \
    procs->name = (type)SelectedGetProcAddress(#name); \
    if (!procs->name) { \
        av_log(opengl, AV_LOG_ERROR, "Cannot load OpenGL function: '%s'\n", #name); \
        return AVERROR(ENOSYS); \
    }

#if HAVE_SDL
    if (!opengl->no_window)
        return opengl_sdl_load_procedures(opengl);
#endif

    LOAD_OPENGL_FUN(glActiveTexture, FF_PFNGLACTIVETEXTUREPROC)
    LOAD_OPENGL_FUN(glGenBuffers, FF_PFNGLGENBUFFERSPROC)
    LOAD_OPENGL_FUN(glDeleteBuffers, FF_PFNGLDELETEBUFFERSPROC)
    LOAD_OPENGL_FUN(glBufferData, FF_PFNGLBUFFERDATAPROC)
    LOAD_OPENGL_FUN(glBindBuffer, FF_PFNGLBINDBUFFERPROC)
    LOAD_OPENGL_FUN(glGetAttribLocation, FF_PFNGLGETATTRIBLOCATIONPROC)
    LOAD_OPENGL_FUN(glGetUniformLocation, FF_PFNGLGETUNIFORMLOCATIONPROC)
    LOAD_OPENGL_FUN(glUniform1f, FF_PFNGLUNIFORM1FPROC)
    LOAD_OPENGL_FUN(glUniform1i, FF_PFNGLUNIFORM1IPROC)
    LOAD_OPENGL_FUN(glUniformMatrix4fv, FF_PFNGLUNIFORMMATRIX4FVPROC)
    LOAD_OPENGL_FUN(glCreateProgram, FF_PFNGLCREATEPROGRAMPROC)
    LOAD_OPENGL_FUN(glDeleteProgram, FF_PFNGLDELETEPROGRAMPROC)
    LOAD_OPENGL_FUN(glUseProgram, FF_PFNGLUSEPROGRAMPROC)
    LOAD_OPENGL_FUN(glLinkProgram, FF_PFNGLLINKPROGRAMPROC)
    LOAD_OPENGL_FUN(glGetProgramiv, FF_PFNGLGETPROGRAMIVPROC)
    LOAD_OPENGL_FUN(glGetProgramInfoLog, FF_PFNGLGETPROGRAMINFOLOGPROC)
    LOAD_OPENGL_FUN(glAttachShader, FF_PFNGLATTACHSHADERPROC)
    LOAD_OPENGL_FUN(glCreateShader, FF_PFNGLCREATESHADERPROC)
    LOAD_OPENGL_FUN(glDeleteShader, FF_PFNGLDELETESHADERPROC)
    LOAD_OPENGL_FUN(glCompileShader, FF_PFNGLCOMPILESHADERPROC)
    LOAD_OPENGL_FUN(glShaderSource, FF_PFNGLSHADERSOURCEPROC)
    LOAD_OPENGL_FUN(glGetShaderiv, FF_PFNGLGETSHADERIVPROC)
    LOAD_OPENGL_FUN(glGetShaderInfoLog, FF_PFNGLGETSHADERINFOLOGPROC)
    LOAD_OPENGL_FUN(glEnableVertexAttribArray, FF_PFNGLENABLEVERTEXATTRIBARRAYPROC)
    LOAD_OPENGL_FUN(glVertexAttribPointer, FF_PFNGLVERTEXATTRIBPOINTERPROC)

    return 0;

#undef SelectedGetProcAddress
#undef LOAD_OPENGL_FUN
}
#endif

static void opengl_make_identity(float matrix[16])
{
    memset(matrix, 0, 16 * sizeof(float));
    matrix[0] = matrix[5] = matrix[10] = matrix[15] = 1.0f;
}

static void opengl_make_ortho(float matrix[16], float left, float right,
                              float bottom, float top, float nearZ, float farZ)
{
    float ral = right + left;
    float rsl = right - left;
    float tab = top + bottom;
    float tsb = top - bottom;
    float fan = farZ + nearZ;
    float fsn = farZ - nearZ;

    memset(matrix, 0, 16 * sizeof(float));
    matrix[0] = 2.0f / rsl;
    matrix[5] = 2.0f / tsb;
    matrix[10] = -2.0f / fsn;
    matrix[12] = -ral / rsl;
    matrix[13] = -tab / tsb;
    matrix[14] = -fan / fsn;
    matrix[15] = 1.0f;
}

static av_cold int opengl_read_limits(OpenGLContext *opengl)
{
    static const struct{
        const char *extension;
        int major;
        int minor;
    } required_extensions[] = {
        { "GL_ARB_multitexture",         1, 3 },
        { "GL_ARB_vertex_buffer_object", 1, 5 }, //GLX_ARB_vertex_buffer_object
        { "GL_ARB_vertex_shader",        2, 0 },
        { "GL_ARB_fragment_shader",      2, 0 },
        { "GL_ARB_shader_objects",       2, 0 },
        { NULL,                          0, 0 }
    };
    int i, major, minor;
    const char *extensions, *version;

    version = glGetString(GL_VERSION);
    extensions = glGetString(GL_EXTENSIONS);

    av_log(opengl, AV_LOG_DEBUG, "OpenGL version: %s\n", version);
    sscanf(version, "%d.%d", &major, &minor);

    for (i = 0; required_extensions[i].extension; i++) {
        if (major < required_extensions[i].major &&
            (major == required_extensions[i].major && minor < required_extensions[i].minor) &&
            !strstr(extensions, required_extensions[i].extension)) {
            av_log(opengl, AV_LOG_ERROR, "Required extension %s is not supported.\n",
                   required_extensions[i].extension);
            av_log(opengl, AV_LOG_DEBUG, "Supported extensions are: %s\n", extensions);
            return AVERROR(ENOSYS);
        }
    }
    glGetIntegerv(GL_MAX_TEXTURE_SIZE, &opengl->max_texture_size);
    glGetIntegerv(GL_MAX_VIEWPORT_DIMS, &opengl->max_viewport_width);
    opengl->non_pow_2_textures = major >= 2 || strstr(extensions, "GL_ARB_texture_non_power_of_two");
#if defined(GL_ES_VERSION_2_0)
    opengl->unpack_subimage = !!strstr(extensions, "GL_EXT_unpack_subimage");
#else
    opengl->unpack_subimage = 1;
#endif

    av_log(opengl, AV_LOG_DEBUG, "Non Power of 2 textures support: %s\n", opengl->non_pow_2_textures ? "Yes" : "No");
    av_log(opengl, AV_LOG_DEBUG, "Unpack Subimage extension support: %s\n", opengl->unpack_subimage ? "Yes" : "No");
    av_log(opengl, AV_LOG_DEBUG, "Max texture size: %dx%d\n", opengl->max_texture_size, opengl->max_texture_size);
    av_log(opengl, AV_LOG_DEBUG, "Max viewport size: %dx%d\n",
           opengl->max_viewport_width, opengl->max_viewport_height);

    OPENGL_ERROR_CHECK(opengl);
    return 0;
  fail:
    return AVERROR_EXTERNAL;
}

static const char* opengl_get_fragment_shader_code(enum AVPixelFormat format)
{
    int i;
    for (i = 0; i < FF_ARRAY_ELEMS(opengl_format_desc); i++) {
        if (opengl_format_desc[i].fixel_format == format)
            return *opengl_format_desc[i].fragment_shader;
    }
    return NULL;
}

static int opengl_type_size(GLenum type)
{
    switch(type) {
    case GL_UNSIGNED_SHORT:
    case FF_GL_UNSIGNED_SHORT_1_5_5_5_REV:
    case GL_UNSIGNED_SHORT_5_6_5:
        return 2;
    case GL_UNSIGNED_BYTE:
    case FF_GL_UNSIGNED_BYTE_3_3_2:
    case FF_GL_UNSIGNED_BYTE_2_3_3_REV:
    default:
        break;
    }
    return 1;
}

static av_cold void opengl_get_texture_params(OpenGLContext *opengl)
{
    int i;
    for (i = 0; i < FF_ARRAY_ELEMS(opengl_format_desc); i++) {
        if (opengl_format_desc[i].fixel_format == opengl->pix_fmt) {
            opengl->format = opengl_format_desc[i].format;
            opengl->type = opengl_format_desc[i].type;
            break;
        }
    }
}

static void opengl_compute_display_area(AVFormatContext *s)
{
    AVRational sar, dar; /* sample and display aspect ratios */
    OpenGLContext *opengl = s->priv_data;
    AVStream *st = s->streams[0];
    AVCodecContext *encctx = st->codec;

    /* compute overlay width and height from the codec context information */
    sar = st->sample_aspect_ratio.num ? st->sample_aspect_ratio : (AVRational){ 1, 1 };
    dar = av_mul_q(sar, (AVRational){ encctx->width, encctx->height });

    /* we suppose the screen has a 1/1 sample aspect ratio */
    /* fit in the window */
    if (av_cmp_q(dar, (AVRational){ opengl->window_width, opengl->window_height }) > 0) {
        /* fit in width */
        opengl->picture_width = opengl->window_width;
        opengl->picture_height = av_rescale(opengl->picture_width, dar.den, dar.num);
    } else {
        /* fit in height */
        opengl->picture_height = opengl->window_height;
        opengl->picture_width = av_rescale(opengl->picture_height, dar.num, dar.den);
    }
}

static av_cold void opengl_get_texture_size(OpenGLContext *opengl, int in_width, int in_height,
                                            int *out_width, int *out_height)
{
    if (opengl->non_pow_2_textures) {
        *out_width = in_width;
        *out_height = in_height;
    } else {
        int max = FFMIN(FFMAX(in_width, in_height), opengl->max_texture_size);
        unsigned power_of_2 = 1;
        while (power_of_2 < max)
            power_of_2 *= 2;
        *out_height = power_of_2;
        *out_width = power_of_2;
        av_log(opengl, AV_LOG_DEBUG, "Texture size calculated from %dx%d into %dx%d\n",
               in_width, in_height, *out_width, *out_height);
    }
}

static av_cold void opengl_fill_color_map(OpenGLContext *opengl)
{
    const AVPixFmtDescriptor *desc;
    int shift;
    enum AVPixelFormat pix_fmt = opengl->pix_fmt;

    /* We need order of components, not exact position, some minor HACKs here */
    if (pix_fmt == AV_PIX_FMT_RGB565 || pix_fmt == AV_PIX_FMT_BGR555 ||
        pix_fmt == AV_PIX_FMT_BGR8   || pix_fmt == AV_PIX_FMT_RGB8)
        pix_fmt = AV_PIX_FMT_RGB24;
    else if (pix_fmt == AV_PIX_FMT_BGR565 || pix_fmt == AV_PIX_FMT_RGB555)
        pix_fmt = AV_PIX_FMT_BGR24;

    desc = av_pix_fmt_desc_get(pix_fmt);
    if (!(desc->flags & AV_PIX_FMT_FLAG_RGB))
        return;

#define FILL_COMPONENT(i) { \
        shift = (desc->comp[i].depth - 1) >> 3; \
        opengl->color_map[(i << 2) + (desc->comp[i].offset >> shift)] = 1.0; \
    }

    memset(opengl->color_map, 0, sizeof(opengl->color_map));
    FILL_COMPONENT(0);
    FILL_COMPONENT(1);
    FILL_COMPONENT(2);
    if (desc->flags & AV_PIX_FMT_FLAG_ALPHA)
        FILL_COMPONENT(3);

#undef FILL_COMPONENT
}

static av_cold GLuint opengl_load_shader(OpenGLContext *opengl, GLenum type, const char *source)
{
    GLuint shader = opengl->glprocs.glCreateShader(type);
    GLint result;
    if (!shader) {
        av_log(opengl, AV_LOG_ERROR, "glCreateShader() failed\n");
        return 0;
    }
    opengl->glprocs.glShaderSource(shader, 1, &source, NULL);
    opengl->glprocs.glCompileShader(shader);

    opengl->glprocs.glGetShaderiv(shader, FF_GL_COMPILE_STATUS, &result);
    if (!result) {
        char *log;
        opengl->glprocs.glGetShaderiv(shader, FF_GL_INFO_LOG_LENGTH, &result);
        if (result) {
            if ((log = av_malloc(result))) {
                opengl->glprocs.glGetShaderInfoLog(shader, result, NULL, log);
                av_log(opengl, AV_LOG_ERROR, "Compile error: %s\n", log);
                av_free(log);
            }
        }
        goto fail;
    }
    OPENGL_ERROR_CHECK(opengl);
    return shader;
  fail:
    opengl->glprocs.glDeleteShader(shader);
    return 0;
}

static av_cold int opengl_compile_shaders(OpenGLContext *opengl, enum AVPixelFormat pix_fmt)
{
    GLint result;
    const char *fragment_shader_code = opengl_get_fragment_shader_code(pix_fmt);

    if (!fragment_shader_code) {
        av_log(opengl, AV_LOG_ERROR, "Provided pixel format '%s' is not supported\n",
               av_get_pix_fmt_name(pix_fmt));
        return AVERROR(EINVAL);
    }

    opengl->vertex_shader = opengl_load_shader(opengl, FF_GL_VERTEX_SHADER,
                                               FF_OPENGL_VERTEX_SHADER);
    if (!opengl->vertex_shader) {
        av_log(opengl, AV_LOG_ERROR, "Vertex shader loading failed.\n");
        goto fail;
    }
    opengl->fragment_shader = opengl_load_shader(opengl, FF_GL_FRAGMENT_SHADER,
                                                 fragment_shader_code);
    if (!opengl->fragment_shader) {
        av_log(opengl, AV_LOG_ERROR, "Fragment shader loading failed.\n");
        goto fail;
    }

    opengl->program = opengl->glprocs.glCreateProgram();
    if (!opengl->program)
        goto fail;

    opengl->glprocs.glAttachShader(opengl->program, opengl->vertex_shader);
    opengl->glprocs.glAttachShader(opengl->program, opengl->fragment_shader);
    opengl->glprocs.glLinkProgram(opengl->program);

    opengl->glprocs.glGetProgramiv(opengl->program, FF_GL_LINK_STATUS, &result);
    if (!result) {
        char *log;
        opengl->glprocs.glGetProgramiv(opengl->program, FF_GL_INFO_LOG_LENGTH, &result);
        if (result) {
            log = av_malloc(result);
            if (!log)
                goto fail;
            opengl->glprocs.glGetProgramInfoLog(opengl->program, result, NULL, log);
            av_log(opengl, AV_LOG_ERROR, "Link error: %s\n", log);
            av_free(log);
        }
        goto fail;
    }

    opengl->position_attrib = opengl->glprocs.glGetAttribLocation(opengl->program, "a_position");
    opengl->texture_coords_attrib = opengl->glprocs.glGetAttribLocation(opengl->program, "a_textureCoords");
    opengl->projection_matrix_location = opengl->glprocs.glGetUniformLocation(opengl->program, "u_projectionMatrix");
    opengl->model_view_matrix_location = opengl->glprocs.glGetUniformLocation(opengl->program, "u_modelViewMatrix");
    opengl->color_map_location = opengl->glprocs.glGetUniformLocation(opengl->program, "u_colorMap");
    opengl->texture_location[0] = opengl->glprocs.glGetUniformLocation(opengl->program, "u_texture0");
    opengl->texture_location[1] = opengl->glprocs.glGetUniformLocation(opengl->program, "u_texture1");
    opengl->texture_location[2] = opengl->glprocs.glGetUniformLocation(opengl->program, "u_texture2");
    opengl->texture_location[3] = opengl->glprocs.glGetUniformLocation(opengl->program, "u_texture3");
    opengl->chroma_div_w_location = opengl->glprocs.glGetUniformLocation(opengl->program, "u_chroma_div_w");
    opengl->chroma_div_h_location = opengl->glprocs.glGetUniformLocation(opengl->program, "u_chroma_div_h");

    OPENGL_ERROR_CHECK(opengl);
    return 0;
  fail:
    opengl->glprocs.glDeleteShader(opengl->vertex_shader);
    opengl->glprocs.glDeleteShader(opengl->fragment_shader);
    opengl->glprocs.glDeleteProgram(opengl->program);
    opengl->fragment_shader = opengl->vertex_shader = opengl->program = 0;
    return AVERROR_EXTERNAL;
}

static av_cold int opengl_configure_texture(OpenGLContext *opengl, GLuint texture,
                                            GLsizei width, GLsizei height)
{
    if (texture) {
        int new_width, new_height;
        opengl_get_texture_size(opengl, width, height, &new_width, &new_height);
        glBindTexture(GL_TEXTURE_2D, texture);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
        glTexImage2D(GL_TEXTURE_2D, 0, opengl->format, new_width, new_height, 0,
                     opengl->format, opengl->type, NULL);
        OPENGL_ERROR_CHECK(NULL);
    }
    return 0;
  fail:
    return AVERROR_EXTERNAL;
}

static av_cold int opengl_prepare_vertex(AVFormatContext *s)
{
    OpenGLContext *opengl = s->priv_data;
    int tex_w, tex_h;

    if (opengl->window_width > opengl->max_viewport_width || opengl->window_height > opengl->max_viewport_height) {
        opengl->window_width = FFMIN(opengl->window_width, opengl->max_viewport_width);
        opengl->window_height = FFMIN(opengl->window_height, opengl->max_viewport_height);
        av_log(opengl, AV_LOG_WARNING, "Too big viewport requested, limited to %dx%d", opengl->window_width, opengl->window_height);
    }
    glViewport(0, 0, opengl->window_width, opengl->window_height);
    opengl_make_ortho(opengl->projection_matrix,
                      - (float)opengl->window_width  / 2.0f, (float)opengl->window_width  / 2.0f,
                      - (float)opengl->window_height / 2.0f, (float)opengl->window_height / 2.0f,
                      1.0f, -1.0f);
    opengl_make_identity(opengl->model_view_matrix);

    opengl_compute_display_area(s);

    opengl->vertex[0].z = opengl->vertex[1].z = opengl->vertex[2].z = opengl->vertex[3].z = 0.0f;
    opengl->vertex[0].x = opengl->vertex[1].x = - (float)opengl->picture_width / 2.0f;
    opengl->vertex[2].x = opengl->vertex[3].x =   (float)opengl->picture_width / 2.0f;
    opengl->vertex[1].y = opengl->vertex[2].y = - (float)opengl->picture_height / 2.0f;
    opengl->vertex[0].y = opengl->vertex[3].y =   (float)opengl->picture_height / 2.0f;

    opengl_get_texture_size(opengl, opengl->width, opengl->height, &tex_w, &tex_h);

    opengl->vertex[0].s0 = 0.0f;
    opengl->vertex[0].t0 = 0.0f;
    opengl->vertex[1].s0 = 0.0f;
    opengl->vertex[1].t0 = (float)opengl->height / (float)tex_h;
    opengl->vertex[2].s0 = (float)opengl->width  / (float)tex_w;
    opengl->vertex[2].t0 = (float)opengl->height / (float)tex_h;
    opengl->vertex[3].s0 = (float)opengl->width  / (float)tex_w;
    opengl->vertex[3].t0 = 0.0f;

    opengl->glprocs.glBindBuffer(FF_GL_ARRAY_BUFFER, opengl->vertex_buffer);
    opengl->glprocs.glBufferData(FF_GL_ARRAY_BUFFER, sizeof(opengl->vertex), opengl->vertex, FF_GL_STATIC_DRAW);
    opengl->glprocs.glBindBuffer(FF_GL_ARRAY_BUFFER, 0);
    OPENGL_ERROR_CHECK(opengl);
    return 0;
  fail:
    return AVERROR_EXTERNAL;
}

static int opengl_prepare(OpenGLContext *opengl)
{
    int i;
    opengl->glprocs.glUseProgram(opengl->program);
    opengl->glprocs.glUniformMatrix4fv(opengl->projection_matrix_location, 1, GL_FALSE, opengl->projection_matrix);
    opengl->glprocs.glUniformMatrix4fv(opengl->model_view_matrix_location, 1, GL_FALSE, opengl->model_view_matrix);
    for (i = 0; i < 4; i++)
        if (opengl->texture_location[i] != -1) {
            opengl->glprocs.glActiveTexture(GL_TEXTURE0 + i);
            glBindTexture(GL_TEXTURE_2D, opengl->texture_name[i]);
            opengl->glprocs.glUniform1i(opengl->texture_location[i], i);
        }
    if (opengl->color_map_location != -1)
        opengl->glprocs.glUniformMatrix4fv(opengl->color_map_location, 1, GL_FALSE, opengl->color_map);
    if (opengl->chroma_div_h_location != -1)
        opengl->glprocs.glUniform1f(opengl->chroma_div_h_location, opengl->chroma_div_h);
    if (opengl->chroma_div_w_location != -1)
        opengl->glprocs.glUniform1f(opengl->chroma_div_w_location, opengl->chroma_div_w);

    OPENGL_ERROR_CHECK(opengl);
    return 0;
  fail:
    return AVERROR_EXTERNAL;
}

static int opengl_create_window(AVFormatContext *h)
{
    OpenGLContext *opengl = h->priv_data;
    int ret;

    if (!opengl->no_window) {
#if HAVE_SDL
        if ((ret = opengl_sdl_create_window(h)) < 0) {
            av_log(opengl, AV_LOG_ERROR, "Cannot create default SDL window.\n");
            return ret;
        }
#else
        av_log(opengl, AV_LOG_ERROR, "FFmpeg is compiled without SDL. Cannot create default window.\n");
        return AVERROR(ENOSYS);
#endif
    } else {
        AVDeviceRect message;
        message.x = message.y = 0;
        message.width = opengl->window_width;
        message.height = opengl->window_height;
        if ((ret = avdevice_dev_to_app_control_message(h, AV_DEV_TO_APP_CREATE_WINDOW_BUFFER,
                                                       &message , sizeof(message))) < 0) {
            av_log(opengl, AV_LOG_ERROR, "Application failed to create window buffer.\n");
            return ret;
        }
        if ((ret = avdevice_dev_to_app_control_message(h, AV_DEV_TO_APP_PREPARE_WINDOW_BUFFER, NULL , 0)) < 0) {
            av_log(opengl, AV_LOG_ERROR, "Application failed to prepare window buffer.\n");
            return ret;
        }
    }
    return 0;
}

static int opengl_release_window(AVFormatContext *h)
{
    int ret;
    OpenGLContext *opengl = h->priv_data;
    if (!opengl->no_window) {
#if HAVE_SDL
        SDL_Quit();
#endif
    } else if ((ret = avdevice_dev_to_app_control_message(h, AV_DEV_TO_APP_DESTROY_WINDOW_BUFFER, NULL , 0)) < 0) {
        av_log(opengl, AV_LOG_ERROR, "Application failed to release window buffer.\n");
        return ret;
    }
    return 0;
}

static av_cold int opengl_write_trailer(AVFormatContext *h)
{
    OpenGLContext *opengl = h->priv_data;

    if (opengl->no_window &&
        avdevice_dev_to_app_control_message(h, AV_DEV_TO_APP_PREPARE_WINDOW_BUFFER, NULL , 0) < 0)
        av_log(opengl, AV_LOG_ERROR, "Application failed to prepare window buffer.\n");

    opengl_deinit_context(opengl);
    opengl_release_window(h);

    return 0;
}

static av_cold int opengl_init_context(OpenGLContext *opengl)
{
    int i, ret;
    const AVPixFmtDescriptor *desc;

    if ((ret = opengl_compile_shaders(opengl, opengl->pix_fmt)) < 0)
        goto fail;

    desc = av_pix_fmt_desc_get(opengl->pix_fmt);
    av_assert0(desc->nb_components > 0 && desc->nb_components <= 4);
    glGenTextures(desc->nb_components, opengl->texture_name);

    opengl->glprocs.glGenBuffers(2, &opengl->index_buffer);
    if (!opengl->index_buffer || !opengl->vertex_buffer) {
        av_log(opengl, AV_LOG_ERROR, "Buffer generation failed.\n");
        ret = AVERROR_EXTERNAL;
        goto fail;
    }

    opengl_configure_texture(opengl, opengl->texture_name[0], opengl->width, opengl->height);
    if (desc->nb_components > 1) {
        int has_alpha = desc->flags & AV_PIX_FMT_FLAG_ALPHA;
        int num_planes = desc->nb_components - (has_alpha ? 1 : 0);
        if (opengl->non_pow_2_textures) {
            opengl->chroma_div_w = 1.0f;
            opengl->chroma_div_h = 1.0f;
        } else {
            opengl->chroma_div_w = 1 << desc->log2_chroma_w;
            opengl->chroma_div_h = 1 << desc->log2_chroma_h;
        }
        for (i = 1; i < num_planes; i++)
            if (opengl->non_pow_2_textures)
                opengl_configure_texture(opengl, opengl->texture_name[i],
                        FF_CEIL_RSHIFT(opengl->width, desc->log2_chroma_w),
                        FF_CEIL_RSHIFT(opengl->height, desc->log2_chroma_h));
            else
                opengl_configure_texture(opengl, opengl->texture_name[i], opengl->width, opengl->height);
        if (has_alpha)
            opengl_configure_texture(opengl, opengl->texture_name[3], opengl->width, opengl->height);
    }

    opengl->glprocs.glBindBuffer(FF_GL_ELEMENT_ARRAY_BUFFER, opengl->index_buffer);
    opengl->glprocs.glBufferData(FF_GL_ELEMENT_ARRAY_BUFFER, sizeof(g_index), g_index, FF_GL_STATIC_DRAW);
    opengl->glprocs.glBindBuffer(FF_GL_ELEMENT_ARRAY_BUFFER, 0);

    glEnable(GL_BLEND);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

    glClearColor((float)opengl->background[0] / 255.0f, (float)opengl->background[1] / 255.0f,
                 (float)opengl->background[2] / 255.0f, 1.0f);

    ret = AVERROR_EXTERNAL;
    OPENGL_ERROR_CHECK(opengl);

    return 0;
  fail:
    return ret;
}

static av_cold int opengl_write_header(AVFormatContext *h)
{
    OpenGLContext *opengl = h->priv_data;
    AVStream *st;
    int ret;

    if (h->nb_streams != 1 ||
        h->streams[0]->codec->codec_type != AVMEDIA_TYPE_VIDEO ||
        h->streams[0]->codec->codec_id != AV_CODEC_ID_RAWVIDEO) {
        av_log(opengl, AV_LOG_ERROR, "Only a single video stream is supported.\n");
        return AVERROR(EINVAL);
    }
    st = h->streams[0];
    opengl->width = st->codec->width;
    opengl->height = st->codec->height;
    opengl->pix_fmt = st->codec->pix_fmt;
    if (!opengl->window_width)
        opengl->window_width = opengl->width;
    if (!opengl->window_height)
        opengl->window_height = opengl->height;

    if (!opengl->window_title && !opengl->no_window)
        opengl->window_title = av_strdup(h->filename);

    if ((ret = opengl_create_window(h)))
        goto fail;

    if ((ret = opengl_read_limits(opengl)) < 0)
        goto fail;

    if (opengl->width > opengl->max_texture_size || opengl->height > opengl->max_texture_size) {
        av_log(opengl, AV_LOG_ERROR, "Too big picture %dx%d, max supported size is %dx%d\n",
               opengl->width, opengl->height, opengl->max_texture_size, opengl->max_texture_size);
        ret = AVERROR(EINVAL);
        goto fail;
    }

    if ((ret = opengl_load_procedures(opengl)) < 0)
        goto fail;

    opengl_fill_color_map(opengl);
    opengl_get_texture_params(opengl);

    if ((ret = opengl_init_context(opengl)) < 0)
        goto fail;

    if ((ret = opengl_prepare_vertex(h)) < 0)
        goto fail;

    glClear(GL_COLOR_BUFFER_BIT);

#if HAVE_SDL
    if (!opengl->no_window)
        SDL_GL_SwapBuffers();
#endif
    if (opengl->no_window &&
        (ret = avdevice_dev_to_app_control_message(h, AV_DEV_TO_APP_DISPLAY_WINDOW_BUFFER, NULL , 0)) < 0) {
        av_log(opengl, AV_LOG_ERROR, "Application failed to display window buffer.\n");
        goto fail;
    }

    ret = AVERROR_EXTERNAL;
    OPENGL_ERROR_CHECK(opengl);

    opengl->inited = 1;
    return 0;

  fail:
    opengl_write_trailer(h);
    return ret;
}

static uint8_t* opengl_get_plane_pointer(OpenGLContext *opengl, AVPacket *pkt, int comp_index,
                                         const AVPixFmtDescriptor *desc)
{
    uint8_t *data = pkt->data;
    int wordsize = opengl_type_size(opengl->type);
    int width_chroma = FF_CEIL_RSHIFT(opengl->width, desc->log2_chroma_w);
    int height_chroma = FF_CEIL_RSHIFT(opengl->height, desc->log2_chroma_h);
    int plane = desc->comp[comp_index].plane;

    switch(plane) {
    case 0:
        break;
    case 1:
        data += opengl->width * opengl->height * wordsize;
        break;
    case 2:
        data += opengl->width * opengl->height * wordsize;
        data += width_chroma * height_chroma * wordsize;
        break;
    case 3:
        data += opengl->width * opengl->height * wordsize;
        data += 2 * width_chroma * height_chroma * wordsize;
        break;
    default:
        return NULL;
    }
    return data;
}

#define LOAD_TEXTURE_DATA(comp_index, sub)                                                  \
{                                                                                           \
    int width = sub ? FF_CEIL_RSHIFT(opengl->width, desc->log2_chroma_w) : opengl->width;   \
    int height = sub ? FF_CEIL_RSHIFT(opengl->height, desc->log2_chroma_h): opengl->height; \
    uint8_t *data;                                                                          \
    int plane = desc->comp[comp_index].plane;                                               \
                                                                                            \
    glBindTexture(GL_TEXTURE_2D, opengl->texture_name[comp_index]);                         \
    if (!is_pkt) {                                                                          \
        GLint length = ((AVFrame *)input)->linesize[plane];                                 \
        int bytes_per_pixel = opengl_type_size(opengl->type);                               \
        if (!(desc->flags & AV_PIX_FMT_FLAG_PLANAR))                                        \
            bytes_per_pixel *= desc->nb_components;                                         \
        data = ((AVFrame *)input)->data[plane];                                             \
        if (!(length % bytes_per_pixel) &&                                                  \
            (opengl->unpack_subimage || ((length / bytes_per_pixel) == width))) {           \
            length /= bytes_per_pixel;                                                      \
            if (length != width)                                                            \
                glPixelStorei(FF_GL_UNPACK_ROW_LENGTH, length);                             \
            glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width, height,                          \
                            opengl->format, opengl->type, data);                            \
            if (length != width)                                                            \
                glPixelStorei(FF_GL_UNPACK_ROW_LENGTH, 0);                                  \
        } else {                                                                            \
            int h;                                                                          \
            for (h = 0; h < height; h++) {                                                  \
                glTexSubImage2D(GL_TEXTURE_2D, 0, 0, h, width, 1,                           \
                                opengl->format, opengl->type, data);                        \
                data += length;                                                             \
            }                                                                               \
        }                                                                                   \
    } else {                                                                                \
        data = opengl_get_plane_pointer(opengl, input, comp_index, desc);                   \
        glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width, height,                              \
                        opengl->format, opengl->type, data);                                \
    }                                                                                       \
}

static int opengl_draw(AVFormatContext *h, void *input, int repaint, int is_pkt)
{
    OpenGLContext *opengl = h->priv_data;
    enum AVPixelFormat pix_fmt = h->streams[0]->codec->pix_fmt;
    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
    int ret;

#if HAVE_SDL
    if (!opengl->no_window && (ret = opengl_sdl_process_events(h)) < 0)
        goto fail;
#endif
    if (opengl->no_window &&
        (ret = avdevice_dev_to_app_control_message(h, AV_DEV_TO_APP_PREPARE_WINDOW_BUFFER, NULL , 0)) < 0) {
        av_log(opengl, AV_LOG_ERROR, "Application failed to prepare window buffer.\n");
        goto fail;
    }

    glClear(GL_COLOR_BUFFER_BIT);

    if (!repaint) {
        if (is_pkt)
            glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
        LOAD_TEXTURE_DATA(0, 0)
        if (desc->flags & AV_PIX_FMT_FLAG_PLANAR) {
            LOAD_TEXTURE_DATA(1, 1)
            LOAD_TEXTURE_DATA(2, 1)
            if (desc->flags & AV_PIX_FMT_FLAG_ALPHA)
                LOAD_TEXTURE_DATA(3, 0)
        }
    }
    ret = AVERROR_EXTERNAL;
    OPENGL_ERROR_CHECK(opengl);

    if ((ret = opengl_prepare(opengl)) < 0)
        goto fail;

    opengl->glprocs.glBindBuffer(FF_GL_ARRAY_BUFFER, opengl->vertex_buffer);
    opengl->glprocs.glBindBuffer(FF_GL_ELEMENT_ARRAY_BUFFER, opengl->index_buffer);
    opengl->glprocs.glVertexAttribPointer(opengl->position_attrib, 3, GL_FLOAT, GL_FALSE, sizeof(OpenGLVertexInfo), 0);
    opengl->glprocs.glEnableVertexAttribArray(opengl->position_attrib);
    opengl->glprocs.glVertexAttribPointer(opengl->texture_coords_attrib, 2, GL_FLOAT, GL_FALSE, sizeof(OpenGLVertexInfo), 12);
    opengl->glprocs.glEnableVertexAttribArray(opengl->texture_coords_attrib);

    glDrawElements(GL_TRIANGLES, FF_ARRAY_ELEMS(g_index), GL_UNSIGNED_SHORT, 0);

    ret = AVERROR_EXTERNAL;
    OPENGL_ERROR_CHECK(opengl);

#if HAVE_SDL
    if (!opengl->no_window)
        SDL_GL_SwapBuffers();
#endif
    if (opengl->no_window &&
        (ret = avdevice_dev_to_app_control_message(h, AV_DEV_TO_APP_DISPLAY_WINDOW_BUFFER, NULL , 0)) < 0) {
        av_log(opengl, AV_LOG_ERROR, "Application failed to display window buffer.\n");
        goto fail;
    }

    return 0;
  fail:
    return ret;
}

static int opengl_write_packet(AVFormatContext *h, AVPacket *pkt)
{
    return opengl_draw(h, pkt, 0, 1);
}

static int opengl_write_frame(AVFormatContext *h, int stream_index,
                              AVFrame **frame, unsigned flags)
{
    if ((flags & AV_WRITE_UNCODED_FRAME_QUERY))
        return 0;
    return opengl_draw(h, *frame, 0, 0);
}

#define OFFSET(x) offsetof(OpenGLContext, x)
#define ENC AV_OPT_FLAG_ENCODING_PARAM
static const AVOption options[] = {
    { "background",   "set background color",   OFFSET(background),   AV_OPT_TYPE_COLOR,  {.str = "black"}, CHAR_MIN, CHAR_MAX, ENC },
    { "no_window",    "disable default window", OFFSET(no_window),    AV_OPT_TYPE_INT,    {.i64 = 0}, INT_MIN, INT_MAX, ENC },
    { "window_title", "set window title",       OFFSET(window_title), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, ENC },
    { "window_size",  "set window size",        OFFSET(window_width), AV_OPT_TYPE_IMAGE_SIZE, {.str = NULL}, 0, 0, ENC },
    { NULL }
};

static const AVClass opengl_class = {
    .class_name = "opengl outdev",
    .item_name  = av_default_item_name,
    .option     = options,
    .version    = LIBAVUTIL_VERSION_INT,
    .category   = AV_CLASS_CATEGORY_DEVICE_VIDEO_OUTPUT,
};

AVOutputFormat ff_opengl_muxer = {
    .name           = "opengl",
    .long_name      = NULL_IF_CONFIG_SMALL("OpenGL output"),
    .priv_data_size = sizeof(OpenGLContext),
    .audio_codec    = AV_CODEC_ID_NONE,
    .video_codec    = AV_CODEC_ID_RAWVIDEO,
    .write_header   = opengl_write_header,
    .write_packet   = opengl_write_packet,
    .write_uncoded_frame = opengl_write_frame,
    .write_trailer  = opengl_write_trailer,
    .control_message = opengl_control_message,
    .flags          = AVFMT_NOFILE | AVFMT_VARIABLE_FPS | AVFMT_NOTIMESTAMPS,
    .priv_class     = &opengl_class,
};