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
|
\input texinfo @c -*- texinfo -*-
@settitle Libavcodec Documentation
@titlepage
@center @titlefont{Libavcodec Documentation}
@end titlepage
@top
@contents
@chapter Description
@c man begin DESCRIPTION
The libavcodec library provides a generic encoding/decoding framework
and contains multiple decoders and encoders for audio, video and
subtitle streams.
The shared architecture provides various services ranging from bit
stream I/O to DSP optimizations, and makes it suitable for
implementing robust and fast codecs as well as for experimentation.
@c man end DESCRIPTION
@chapter Codec Options
@c man begin CODEC OPTIONS
libavcodec provides some generic global options, which can be set on
all the encoders and decoders. In addition each codec may support
so-called private options, which are specific for a given codec.
Sometimes, a global option may only affect a specific kind of codec,
and may be unsensical or ignored by another, so you need to be aware
of the meaning of the specified options. Also some options are
meant only for decoding or encoding.
Options may be set by specifying -@var{option} @var{value} in the
FFmpeg tools, or by setting the value explicitly in the
@code{AVCodecContext} options or using the @file{libavutil/opt.h} API
for programmatic use.
The list of supported options follow:
@table @option
@item b @var{integer} (@emph{encoding,audio,video})
Set bitrate in bits/s. Default value is 200K.
@item ab @var{integer} (@emph{encoding,audio})
Set audio bitrate (in bits/s). Default value is 128K.
@item bt @var{integer} (@emph{encoding,video})
Set video bitrate tolerance (in bits/s). In 1-pass mode, bitrate
tolerance specifies how far ratecontrol is willing to deviate from the
target average bitrate value. This is not related to min/max
bitrate. Lowering tolerance too much has an adverse effect on quality.
@item flags @var{flags} (@emph{decoding/encoding,audio,video,subtitles})
Set generic flags.
Possible values:
@table @samp
@item mv4
Use four motion vector by macroblock (mpeg4).
@item qpel
Use 1/4 pel motion compensation.
@item loop
Use loop filter.
@item qscale
Use fixed qscale.
@item gmc
Use gmc.
@item mv0
Always try a mb with mv=<0,0>.
@item input_preserved
@item pass1
Use internal 2pass ratecontrol in first pass mode.
@item pass2
Use internal 2pass ratecontrol in second pass mode.
@item gray
Only decode/encode grayscale.
@item emu_edge
Do not draw edges.
@item psnr
Set error[?] variables during encoding.
@item truncated
@item naq
Normalize adaptive quantization.
@item ildct
Use interlaced DCT.
@item low_delay
Force low delay.
@item global_header
Place global headers in extradata instead of every keyframe.
@item bitexact
Use only bitexact stuff (except (I)DCT).
@item aic
Apply H263 advanced intra coding / mpeg4 ac prediction.
@item cbp
Deprecated, use mpegvideo private options instead.
@item qprd
Deprecated, use mpegvideo private options instead.
@item ilme
Apply interlaced motion estimation.
@item cgop
Use closed gop.
@end table
@item sub_id @var{integer}
Deprecated, currently unused.
@item me_method @var{integer} (@emph{encoding,video})
Set motion estimation method.
Possible values:
@table @samp
@item zero
zero motion estimation (fastest)
@item full
full motion estimation (slowest)
@item epzs
EPZS motion estimation (default)
@item esa
esa motion estimation (alias for full)
@item tesa
tesa motion estimation
@item dia
dia motion estimation (alias for epzs)
@item log
log motion estimation
@item phods
phods motion estimation
@item x1
X1 motion estimation
@item hex
hex motion estimation
@item umh
umh motion estimation
@item iter
iter motion estimation
@end table
@item extradata_size @var{integer}
Set extradata size.
@item time_base @var{rational number}
Set codec time base.
It is the fundamental unit of time (in seconds) in terms of which
frame timestamps are represented. For fixed-fps content, timebase
should be 1/framerate and timestamp increments should be identically
1.
@item g @var{integer} (@emph{encoding,video})
Set the group of picture size. Default value is 12.
@item ar @var{integer} (@emph{decoding/encoding,audio})
Set audio sampling rate (in Hz).
@item ac @var{integer} (@emph{decoding/encoding,audio})
Set number of audio channels.
@item cutoff @var{integer} (@emph{encoding,audio})
Set cutoff bandwidth.
@item frame_size @var{integer} (@emph{encoding,audio})
Set audio frame size.
Each submitted frame except the last must contain exactly frame_size
samples per channel. May be 0 when the codec has
CODEC_CAP_VARIABLE_FRAME_SIZE set, in that case the frame size is not
restricted. It is set by some decoders to indicate constant frame
size.
@item frame_number @var{integer}
Set the frame number.
@item delay @var{integer}
@item qcomp @var{float} (@emph{encoding,video})
Set video quantizer scale compression (VBR). It is used as a constant
in the ratecontrol equation. Recommended range for default rc_eq:
0.0-1.0.
@item qblur @var{float} (@emph{encoding,video})
Set video quantizer scale blur (VBR).
@item qmin @var{integer} (@emph{encoding,video})
Set min video quantizer scale (VBR). Must be included between -1 and
69, default value is 2.
@item qmax @var{integer} (@emph{encoding,video})
Set max video quantizer scale (VBR). Must be included between -1 and
1024, default value is 31.
@item qdiff @var{integer} (@emph{encoding,video})
Set max difference between the quantizer scale (VBR).
@item bf @var{integer} (@emph{encoding,video})
Set max number of B frames.
@item b_qfactor @var{float} (@emph{encoding,video})
Set qp factor between P and B frames.
@item rc_strategy @var{integer} (@emph{encoding,video})
Set ratecontrol method.
@item b_strategy @var{integer} (@emph{encoding,video})
Set strategy to choose between I/P/B-frames.
@item ps @var{integer} (@emph{encoding,video})
Set RTP payload size in bytes.
@item mv_bits @var{integer}
@item header_bits @var{integer}
@item i_tex_bits @var{integer}
@item p_tex_bits @var{integer}
@item i_count @var{integer}
@item p_count @var{integer}
@item skip_count @var{integer}
@item misc_bits @var{integer}
@item frame_bits @var{integer}
@item codec_tag @var{integer}
@item bug @var{flags} (@emph{decoding,video})
Workaround not auto detected encoder bugs.
Possible values:
@table @samp
@item autodetect
@item old_msmpeg4
some old lavc generated msmpeg4v3 files (no autodetection)
@item xvid_ilace
Xvid interlacing bug (autodetected if fourcc==XVIX)
@item ump4
(autodetected if fourcc==UMP4)
@item no_padding
padding bug (autodetected)
@item amv
@item ac_vlc
illegal vlc bug (autodetected per fourcc)
@item qpel_chroma
@item std_qpel
old standard qpel (autodetected per fourcc/version)
@item qpel_chroma2
@item direct_blocksize
direct-qpel-blocksize bug (autodetected per fourcc/version)
@item edge
edge padding bug (autodetected per fourcc/version)
@item hpel_chroma
@item dc_clip
@item ms
Workaround various bugs in microsoft broken decoders.
@item trunc
trancated frames
@end table
@item lelim @var{integer} (@emph{encoding,video})
Set single coefficient elimination threshold for luminance (negative
values also consider DC coefficient).
@item celim @var{integer} (@emph{encoding,video})
Set single coefficient elimination threshold for chrominance (negative
values also consider dc coefficient)
@item strict @var{integer} (@emph{decoding/encoding,audio,video})
Specify how strictly to follow the standards.
Possible values:
@table @samp
@item very
strictly conform to a older more strict version of the spec or reference software
@item strict
strictly conform to all the things in the spec no matter what consequences
@item normal
@item unofficial
allow unofficial extensions
@item experimental
allow non standardized experimental things
@end table
@item b_qoffset @var{float} (@emph{encoding,video})
Set QP offset between P and B frames.
@item err_detect @var{flags} (@emph{decoding,audio,video})
Set error detection flags.
Possible values:
@table @samp
@item crccheck
verify embedded CRCs
@item bitstream
detect bitstream specification deviations
@item buffer
detect improper bitstream length
@item explode
abort decoding on minor error detection
@item careful
consider things that violate the spec and have not been seen in the wild as errors
@item compliant
consider all spec non compliancies as errors
@item aggressive
consider things that a sane encoder should not do as an error
@end table
@item has_b_frames @var{integer}
@item block_align @var{integer}
@item mpeg_quant @var{integer} (@emph{encoding,video})
Use MPEG quantizers instead of H.263.
@item qsquish @var{float} (@emph{encoding,video})
How to keep quantizer between qmin and qmax (0 = clip, 1 = use
differentiable function).
@item rc_qmod_amp @var{float} (@emph{encoding,video})
Set experimental quantizer modulation.
@item rc_qmod_freq @var{integer} (@emph{encoding,video})
Set experimental quantizer modulation.
@item rc_override_count @var{integer}
@item rc_eq @var{string} (@emph{encoding,video})
Set rate control equation. When computing the expression, besides the
standard functions defined in the section 'Expression Evaluation', the
following functions are available: bits2qp(bits), qp2bits(qp). Also
the following constants are available: iTex pTex tex mv fCode iCount
mcVar var isI isP isB avgQP qComp avgIITex avgPITex avgPPTex avgBPTex
avgTex.
@item maxrate @var{integer} (@emph{encoding,audio,video})
Set max bitrate tolerance (in bits/s). Requires bufsize to be set.
@item minrate @var{integer} (@emph{encoding,audio,video})
Set min bitrate tolerance (in bits/s). Most useful in setting up a CBR
encode. It is of little use elsewise.
@item bufsize @var{integer} (@emph{encoding,audio,video})
Set ratecontrol buffer size (in bits).
@item rc_buf_aggressivity @var{float} (@emph{encoding,video})
Currently useless.
@item i_qfactor @var{float} (@emph{encoding,video})
Set QP factor between P and I frames.
@item i_qoffset @var{float} (@emph{encoding,video})
Set QP offset between P and I frames.
@item rc_init_cplx @var{float} (@emph{encoding,video})
Set initial complexity for 1-pass encoding.
@item dct @var{integer} (@emph{encoding,video})
Set DCT algorithm.
Possible values:
@table @samp
@item auto
autoselect a good one (default)
@item fastint
fast integer
@item int
accurate integer
@item mmx
@item altivec
@item faan
floating point AAN DCT
@end table
@item lumi_mask @var{float} (@emph{encoding,video})
Compress bright areas stronger than medium ones.
@item tcplx_mask @var{float} (@emph{encoding,video})
Set temporal complexity masking.
@item scplx_mask @var{float} (@emph{encoding,video})
Set spatial complexity masking.
@item p_mask @var{float} (@emph{encoding,video})
Set inter masking.
@item dark_mask @var{float} (@emph{encoding,video})
Compress dark areas stronger than medium ones.
@item idct @var{integer} (@emph{decoding/encoding,video})
Select IDCT implementation.
Possible values:
@table @samp
@item auto
@item int
@item simple
@item simplemmx
@item libmpeg2mmx
@item mmi
@item arm
@item altivec
@item sh4
@item simplearm
@item simplearmv5te
@item simplearmv6
@item simpleneon
@item simplealpha
@item h264
@item vp3
@item ipp
@item xvidmmx
@item faani
floating point AAN IDCT
@end table
@item slice_count @var{integer}
@item ec @var{flags} (@emph{decoding,video})
Set error concealment strategy.
Possible values:
@table @samp
@item guess_mvs
iterative motion vector (MV) search (slow)
@item deblock
use strong deblock filter for damaged MBs
@end table
@item bits_per_coded_sample @var{integer}
@item pred @var{integer} (@emph{encoding,video})
Set prediction method.
Possible values:
@table @samp
@item left
@item plane
@item median
@end table
@item aspect @var{rational number} (@emph{encoding,video})
Set sample aspect ratio.
@item debug @var{flags} (@emph{decoding/encoding,audio,video,subtitles})
Print specific debug info.
Possible values:
@table @samp
@item pict
picture info
@item rc
rate control
@item bitstream
@item mb_type
macroblock (MB) type
@item qp
per-block quantization parameter (QP)
@item mv
motion vector
@item dct_coeff
@item skip
@item startcode
@item pts
@item er
error recognition
@item mmco
memory management control operations (H.264)
@item bugs
@item vis_qp
visualize quantization parameter (QP), lower QP are tinted greener
@item vis_mb_type
visualize block types
@item buffers
picture buffer allocations
@item thread_ops
threading operations
@end table
@item vismv @var{integer} (@emph{decoding,video})
Visualize motion vectors (MVs).
Possible values:
@table @samp
@item pf
forward predicted MVs of P-frames
@item bf
forward predicted MVs of B-frames
@item bb
backward predicted MVs of B-frames
@end table
@item cmp @var{integer} (@emph{encoding,video})
Set full pel me compare function.
Possible values:
@table @samp
@item sad
sum of absolute differences, fast (default)
@item sse
sum of squared errors
@item satd
sum of absolute Hadamard transformed differences
@item dct
sum of absolute DCT transformed differences
@item psnr
sum of squared quantization errors (avoid, low quality)
@item bit
number of bits needed for the block
@item rd
rate distortion optimal, slow
@item zero
0
@item vsad
sum of absolute vertical differences
@item vsse
sum of squared vertical differences
@item nsse
noise preserving sum of squared differences
@item w53
5/3 wavelet, only used in snow
@item w97
9/7 wavelet, only used in snow
@item dctmax
@item chroma
@end table
@item subcmp @var{integer} (@emph{encoding,video})
Set sub pel me compare function.
Possible values:
@table @samp
@item sad
sum of absolute differences, fast (default)
@item sse
sum of squared errors
@item satd
sum of absolute Hadamard transformed differences
@item dct
sum of absolute DCT transformed differences
@item psnr
sum of squared quantization errors (avoid, low quality)
@item bit
number of bits needed for the block
@item rd
rate distortion optimal, slow
@item zero
0
@item vsad
sum of absolute vertical differences
@item vsse
sum of squared vertical differences
@item nsse
noise preserving sum of squared differences
@item w53
5/3 wavelet, only used in snow
@item w97
9/7 wavelet, only used in snow
@item dctmax
@item chroma
@end table
@item mbcmp @var{integer} (@emph{encoding,video})
Set macroblock compare function.
Possible values:
@table @samp
@item sad
sum of absolute differences, fast (default)
@item sse
sum of squared errors
@item satd
sum of absolute Hadamard transformed differences
@item dct
sum of absolute DCT transformed differences
@item psnr
sum of squared quantization errors (avoid, low quality)
@item bit
number of bits needed for the block
@item rd
rate distortion optimal, slow
@item zero
0
@item vsad
sum of absolute vertical differences
@item vsse
sum of squared vertical differences
@item nsse
noise preserving sum of squared differences
@item w53
5/3 wavelet, only used in snow
@item w97
9/7 wavelet, only used in snow
@item dctmax
@item chroma
@end table
@item ildctcmp @var{integer} (@emph{encoding,video})
Set interlaced dct compare function.
Possible values:
@table @samp
@item sad
sum of absolute differences, fast (default)
@item sse
sum of squared errors
@item satd
sum of absolute Hadamard transformed differences
@item dct
sum of absolute DCT transformed differences
@item psnr
sum of squared quantization errors (avoid, low quality)
@item bit
number of bits needed for the block
@item rd
rate distortion optimal, slow
@item zero
0
@item vsad
sum of absolute vertical differences
@item vsse
sum of squared vertical differences
@item nsse
noise preserving sum of squared differences
@item w53
5/3 wavelet, only used in snow
@item w97
9/7 wavelet, only used in snow
@item dctmax
@item chroma
@end table
@item dia_size @var{integer} (@emph{encoding,video})
Set diamond type & size for motion estimation.
@item last_pred @var{integer} (@emph{encoding,video})
Set amount of motion predictors from the previous frame.
@item preme @var{integer} (@emph{encoding,video})
Set pre motion estimation.
@item precmp @var{integer} (@emph{encoding,video})
Set pre motion estimation compare function.
Possible values:
@table @samp
@item sad
sum of absolute differences, fast (default)
@item sse
sum of squared errors
@item satd
sum of absolute Hadamard transformed differences
@item dct
sum of absolute DCT transformed differences
@item psnr
sum of squared quantization errors (avoid, low quality)
@item bit
number of bits needed for the block
@item rd
rate distortion optimal, slow
@item zero
0
@item vsad
sum of absolute vertical differences
@item vsse
sum of squared vertical differences
@item nsse
noise preserving sum of squared differences
@item w53
5/3 wavelet, only used in snow
@item w97
9/7 wavelet, only used in snow
@item dctmax
@item chroma
@end table
@item pre_dia_size @var{integer} (@emph{encoding,video})
Set diamond type & size for motion estimation pre-pass.
@item subq @var{integer} (@emph{encoding,video})
Set sub pel motion estimation quality.
@item dtg_active_format @var{integer}
@item me_range @var{integer} (@emph{encoding,video})
Set limit motion vectors range (1023 for DivX player).
@item ibias @var{integer} (@emph{encoding,video})
Set intra quant bias.
@item pbias @var{integer} (@emph{encoding,video})
Set inter quant bias.
@item color_table_id @var{integer}
@item global_quality @var{integer} (@emph{encoding,audio,video})
@item coder @var{integer} (@emph{encoding,video})
Possible values:
@table @samp
@item vlc
variable length coder / huffman coder
@item ac
arithmetic coder
@item raw
raw (no encoding)
@item rle
run-length coder
@item deflate
deflate-based coder
@end table
@item context @var{integer} (@emph{encoding,video})
Set context model.
@item slice_flags @var{integer}
@item xvmc_acceleration @var{integer}
@item mbd @var{integer} (@emph{encoding,video})
Set macroblock decision algorithm (high quality mode).
Possible values:
@table @samp
@item simple
use mbcmp (default)
@item bits
use fewest bits
@item rd
use best rate distortion
@end table
@item stream_codec_tag @var{integer}
@item sc_threshold @var{integer} (@emph{encoding,video})
Set scene change threshold.
@item lmin @var{integer} (@emph{encoding,video})
Set min lagrange factor (VBR).
@item lmax @var{integer} (@emph{encoding,video})
Set max lagrange factor (VBR).
@item nr @var{integer} (@emph{encoding,video})
Set noise reduction.
@item rc_init_occupancy @var{integer} (@emph{encoding,video})
Set number of bits which should be loaded into the rc buffer before
decoding starts.
@item inter_threshold @var{integer} (@emph{encoding,video})
@item flags2 @var{flags} (@emph{decoding/encoding,audio,video})
Possible values:
@table @samp
@item fast
allow non spec compliant speedup tricks
@item sgop
Deprecated, use mpegvideo private options instead
@item noout
skip bitstream encoding
@item local_header
place global headers at every keyframe instead of in extradata
@item chunks
Frame data might be split into multiple chunks
@item showall
Show all frames before the first keyframe
@item skiprd
Deprecated, use mpegvideo private options instead
@end table
@item error @var{integer} (@emph{encoding,video})
@item qns @var{integer} (@emph{encoding,video})
Deprecated, use mpegvideo private options instead.
@item threads @var{integer} (@emph{decoding/encoding,video})
Possible values:
@table @samp
@item auto
detect a good number of threads
@end table
@item me_threshold @var{integer} (@emph{encoding,video})
Set motion estimaton threshold.
@item mb_threshold @var{integer} (@emph{encoding,video})
Set macroblock threshold.
@item dc @var{integer} (@emph{encoding,video})
Set intra_dc_precision.
@item nssew @var{integer} (@emph{encoding,video})
Set nsse weight.
@item skip_top @var{integer} (@emph{decoding,video})
Set number of macroblock rows at the top which are skipped.
@item skip_bottom @var{integer} (@emph{decoding,video})
Set number of macroblock rows at the bottom which are skipped.
@item profile @var{integer} (@emph{encoding,audio,video})
Possible values:
@table @samp
@item unknown
@item aac_main
@item aac_low
@item aac_ssr
@item aac_ltp
@item aac_he
@item aac_he_v2
@item aac_ld
@item aac_eld
@item dts
@item dts_es
@item dts_96_24
@item dts_hd_hra
@item dts_hd_ma
@end table
@item level @var{integer} (@emph{encoding,audio,video})
Possible values:
@table @samp
@item unknown
@end table
@item lowres @var{integer} (@emph{decoding,audio,video})
Decode at 1= 1/2, 2=1/4, 3=1/8 resolutions.
@item skip_threshold @var{integer} (@emph{encoding,video})
Set frame skip threshold.
@item skip_factor @var{integer} (@emph{encoding,video})
Set frame skip factor.
@item skip_exp @var{integer} (@emph{encoding,video})
Set frame skip exponent.
@item skipcmp @var{integer} (@emph{encoding,video})
Set frame skip compare function.
Possible values:
@table @samp
@item sad
sum of absolute differences, fast (default)
@item sse
sum of squared errors
@item satd
sum of absolute Hadamard transformed differences
@item dct
sum of absolute DCT transformed differences
@item psnr
sum of squared quantization errors (avoid, low quality)
@item bit
number of bits needed for the block
@item rd
rate distortion optimal, slow
@item zero
0
@item vsad
sum of absolute vertical differences
@item vsse
sum of squared vertical differences
@item nsse
noise preserving sum of squared differences
@item w53
5/3 wavelet, only used in snow
@item w97
9/7 wavelet, only used in snow
@item dctmax
@item chroma
@end table
@item border_mask @var{float} (@emph{encoding,video})
Increase the quantizer for macroblocks close to borders.
@item mblmin @var{integer} (@emph{encoding,video})
Set min macroblock lagrange factor (VBR).
@item mblmax @var{integer} (@emph{encoding,video})
Set max macroblock lagrange factor (VBR).
@item mepc @var{integer} (@emph{encoding,video})
Set motion estimation bitrate penalty compensation (1.0 = 256).
@item skip_loop_filter @var{integer} (@emph{decoding,video})
Possible values:
@table @samp
@item none
@item default
@item noref
@item bidir
@item nokey
@item all
@end table
@item skip_idct @var{integer} (@emph{decoding,video})
Possible values:
@table @samp
@item none
@item default
@item noref
@item bidir
@item nokey
@item all
@end table
@item skip_frame @var{integer} (@emph{decoding,video})
Possible values:
@table @samp
@item none
@item default
@item noref
@item bidir
@item nokey
@item all
@end table
@item bidir_refine @var{integer} (@emph{encoding,video})
Refine the two motion vectors used in bidirectional macroblocks.
@item brd_scale @var{integer} (@emph{encoding,video})
Downscale frames for dynamic B-frame decision.
@item keyint_min @var{integer} (@emph{encoding,video})
Set minimum interval between IDR-frames.
@item refs @var{integer} (@emph{encoding,video})
Set reference frames to consider for motion compensation.
@item chromaoffset @var{integer} (@emph{encoding,video})
Set chroma qp offset from luma.
@item trellis @var{integer} (@emph{encoding,audio,video})
Set rate-distortion optimal quantization.
@item sc_factor @var{integer} (@emph{encoding,video})
Set value multiplied by qscale for each frame and added to
scene_change_score.
@item mv0_threshold @var{integer} (@emph{encoding,video})
@item b_sensitivity @var{integer} (@emph{encoding,video})
Adjust sensitivity of b_frame_strategy 1.
@item compression_level @var{integer} (@emph{encoding,audio,video})
@item min_prediction_order @var{integer} (@emph{encoding,audio})
@item max_prediction_order @var{integer} (@emph{encoding,audio})
@item timecode_frame_start @var{integer} (@emph{encoding,video})
Set GOP timecode frame start number, in non drop frame format.
@item request_channels @var{integer} (@emph{decoding,audio})
Set desired number of audio channels.
@item bits_per_raw_sample @var{integer}
@item channel_layout @var{integer} (@emph{decoding/encoding,audio})
Possible values:
@table @samp
@end table
@item request_channel_layout @var{integer} (@emph{decoding,audio})
Possible values:
@table @samp
@end table
@item rc_max_vbv_use @var{float} (@emph{encoding,video})
@item rc_min_vbv_use @var{float} (@emph{encoding,video})
@item ticks_per_frame @var{integer} (@emph{decoding/encoding,audio,video})
@item color_primaries @var{integer} (@emph{decoding/encoding,video})
@item color_trc @var{integer} (@emph{decoding/encoding,video})
@item colorspace @var{integer} (@emph{decoding/encoding,video})
@item color_range @var{integer} (@emph{decoding/encoding,video})
@item chroma_sample_location @var{integer} (@emph{decoding/encoding,video})
@item log_level_offset @var{integer}
Set the log level offset.
@item slices @var{integer} (@emph{encoding,video})
Number of slices, used in parallelized encoding.
@item thread_type @var{flags} (@emph{decoding/encoding,video})
Select multithreading type.
Possible values:
@table @samp
@item slice
@item frame
@end table
@item audio_service_type @var{integer} (@emph{encoding,audio})
Set audio service type.
Possible values:
@table @samp
@item ma
Main Audio Service
@item ef
Effects
@item vi
Visually Impaired
@item hi
Hearing Impaired
@item di
Dialogue
@item co
Commentary
@item em
Emergency
@item vo
Voice Over
@item ka
Karaoke
@end table
@item request_sample_fmt @var{sample_fmt} (@emph{decoding,audio})
Set sample format audio decoders should prefer. Default value is
@code{none}.
@item pkt_timebase @var{rational number}
@end table
@c man end CODEC OPTIONS
@include decoders.texi
@include encoders.texi
@ignore
@setfilename libavcodec
@settitle media streams decoding and encoding library
@c man begin SEEALSO
ffmpeg(1), ffplay(1), ffprobe(1), ffserver(1)
@c man end
@c man begin AUTHORS
See Git history (git://source.ffmpeg.org/ffmpeg)
@c man end
@end ignore
@bye
|