1@anchor{codec-options} 2@chapter Codec Options 3@c man begin CODEC OPTIONS 4 5libavcodec provides some generic global options, which can be set on 6all the encoders and decoders. In addition each codec may support 7so-called private options, which are specific for a given codec. 8 9Sometimes, a global option may only affect a specific kind of codec, 10and may be nonsensical or ignored by another, so you need to be aware 11of the meaning of the specified options. Also some options are 12meant only for decoding or encoding. 13 14Options may be set by specifying -@var{option} @var{value} in the 15FFmpeg tools, or by setting the value explicitly in the 16@code{AVCodecContext} options or using the @file{libavutil/opt.h} API 17for programmatic use. 18 19The list of supported options follow: 20 21@table @option 22@item b @var{integer} (@emph{encoding,audio,video}) 23Set bitrate in bits/s. Default value is 200K. 24 25@item ab @var{integer} (@emph{encoding,audio}) 26Set audio bitrate (in bits/s). Default value is 128K. 27 28@item bt @var{integer} (@emph{encoding,video}) 29Set video bitrate tolerance (in bits/s). In 1-pass mode, bitrate 30tolerance specifies how far ratecontrol is willing to deviate from the 31target average bitrate value. This is not related to min/max 32bitrate. Lowering tolerance too much has an adverse effect on quality. 33 34@item flags @var{flags} (@emph{decoding/encoding,audio,video,subtitles}) 35Set generic flags. 36 37Possible values: 38@table @samp 39@item mv4 40Use four motion vector by macroblock (mpeg4). 41@item qpel 42Use 1/4 pel motion compensation. 43@item loop 44Use loop filter. 45@item qscale 46Use fixed qscale. 47@item pass1 48Use internal 2pass ratecontrol in first pass mode. 49@item pass2 50Use internal 2pass ratecontrol in second pass mode. 51@item gray 52Only decode/encode grayscale. 53@item psnr 54Set error[?] variables during encoding. 55@item truncated 56Input bitstream might be randomly truncated. 57@item drop_changed 58Don't output frames whose parameters differ from first decoded frame in stream. 59Error AVERROR_INPUT_CHANGED is returned when a frame is dropped. 60 61@item ildct 62Use interlaced DCT. 63@item low_delay 64Force low delay. 65@item global_header 66Place global headers in extradata instead of every keyframe. 67@item bitexact 68Only write platform-, build- and time-independent data. (except (I)DCT). 69This ensures that file and data checksums are reproducible and match between 70platforms. Its primary use is for regression testing. 71@item aic 72Apply H263 advanced intra coding / mpeg4 ac prediction. 73@item ilme 74Apply interlaced motion estimation. 75@item cgop 76Use closed gop. 77@item output_corrupt 78Output even potentially corrupted frames. 79@end table 80 81@item time_base @var{rational number} 82Set codec time base. 83 84It is the fundamental unit of time (in seconds) in terms of which 85frame timestamps are represented. For fixed-fps content, timebase 86should be @code{1 / frame_rate} and timestamp increments should be 87identically 1. 88 89@item g @var{integer} (@emph{encoding,video}) 90Set the group of picture (GOP) size. Default value is 12. 91 92@item ar @var{integer} (@emph{decoding/encoding,audio}) 93Set audio sampling rate (in Hz). 94 95@item ac @var{integer} (@emph{decoding/encoding,audio}) 96Set number of audio channels. 97 98@item cutoff @var{integer} (@emph{encoding,audio}) 99Set cutoff bandwidth. (Supported only by selected encoders, see 100their respective documentation sections.) 101 102@item frame_size @var{integer} (@emph{encoding,audio}) 103Set audio frame size. 104 105Each submitted frame except the last must contain exactly frame_size 106samples per channel. May be 0 when the codec has 107CODEC_CAP_VARIABLE_FRAME_SIZE set, in that case the frame size is not 108restricted. It is set by some decoders to indicate constant frame 109size. 110 111@item frame_number @var{integer} 112Set the frame number. 113 114@item delay @var{integer} 115 116@item qcomp @var{float} (@emph{encoding,video}) 117Set video quantizer scale compression (VBR). It is used as a constant 118in the ratecontrol equation. Recommended range for default rc_eq: 1190.0-1.0. 120 121@item qblur @var{float} (@emph{encoding,video}) 122Set video quantizer scale blur (VBR). 123 124@item qmin @var{integer} (@emph{encoding,video}) 125Set min video quantizer scale (VBR). Must be included between -1 and 12669, default value is 2. 127 128@item qmax @var{integer} (@emph{encoding,video}) 129Set max video quantizer scale (VBR). Must be included between -1 and 1301024, default value is 31. 131 132@item qdiff @var{integer} (@emph{encoding,video}) 133Set max difference between the quantizer scale (VBR). 134 135@item bf @var{integer} (@emph{encoding,video}) 136Set max number of B frames between non-B-frames. 137 138Must be an integer between -1 and 16. 0 means that B-frames are 139disabled. If a value of -1 is used, it will choose an automatic value 140depending on the encoder. 141 142Default value is 0. 143 144@item b_qfactor @var{float} (@emph{encoding,video}) 145Set qp factor between P and B frames. 146 147@item codec_tag @var{integer} 148@item bug @var{flags} (@emph{decoding,video}) 149Workaround not auto detected encoder bugs. 150 151Possible values: 152@table @samp 153@item autodetect 154 155@item xvid_ilace 156Xvid interlacing bug (autodetected if fourcc==XVIX) 157@item ump4 158(autodetected if fourcc==UMP4) 159@item no_padding 160padding bug (autodetected) 161@item amv 162 163@item qpel_chroma 164 165@item std_qpel 166old standard qpel (autodetected per fourcc/version) 167@item qpel_chroma2 168 169@item direct_blocksize 170direct-qpel-blocksize bug (autodetected per fourcc/version) 171@item edge 172edge padding bug (autodetected per fourcc/version) 173@item hpel_chroma 174 175@item dc_clip 176 177@item ms 178Workaround various bugs in microsoft broken decoders. 179@item trunc 180trancated frames 181@end table 182 183@item strict @var{integer} (@emph{decoding/encoding,audio,video}) 184Specify how strictly to follow the standards. 185 186Possible values: 187@table @samp 188@item very 189strictly conform to an older more strict version of the spec or reference software 190@item strict 191strictly conform to all the things in the spec no matter what consequences 192@item normal 193 194@item unofficial 195allow unofficial extensions 196@item experimental 197allow non standardized experimental things, experimental 198(unfinished/work in progress/not well tested) decoders and encoders. 199Note: experimental decoders can pose a security risk, do not use this for 200decoding untrusted input. 201@end table 202 203@item b_qoffset @var{float} (@emph{encoding,video}) 204Set QP offset between P and B frames. 205 206@item err_detect @var{flags} (@emph{decoding,audio,video}) 207Set error detection flags. 208 209Possible values: 210@table @samp 211@item crccheck 212verify embedded CRCs 213@item bitstream 214detect bitstream specification deviations 215@item buffer 216detect improper bitstream length 217@item explode 218abort decoding on minor error detection 219@item ignore_err 220ignore decoding errors, and continue decoding. 221This is useful if you want to analyze the content of a video and thus want 222everything to be decoded no matter what. This option will not result in a video 223that is pleasing to watch in case of errors. 224@item careful 225consider things that violate the spec and have not been seen in the wild as errors 226@item compliant 227consider all spec non compliancies as errors 228@item aggressive 229consider things that a sane encoder should not do as an error 230@end table 231 232@item has_b_frames @var{integer} 233 234@item block_align @var{integer} 235 236@item rc_override_count @var{integer} 237 238@item maxrate @var{integer} (@emph{encoding,audio,video}) 239Set max bitrate tolerance (in bits/s). Requires bufsize to be set. 240 241@item minrate @var{integer} (@emph{encoding,audio,video}) 242Set min bitrate tolerance (in bits/s). Most useful in setting up a CBR 243encode. It is of little use elsewise. 244 245@item bufsize @var{integer} (@emph{encoding,audio,video}) 246Set ratecontrol buffer size (in bits). 247 248@item i_qfactor @var{float} (@emph{encoding,video}) 249Set QP factor between P and I frames. 250 251@item i_qoffset @var{float} (@emph{encoding,video}) 252Set QP offset between P and I frames. 253 254@item dct @var{integer} (@emph{encoding,video}) 255Set DCT algorithm. 256 257Possible values: 258@table @samp 259@item auto 260autoselect a good one (default) 261@item fastint 262fast integer 263@item int 264accurate integer 265@item mmx 266 267@item altivec 268 269@item faan 270floating point AAN DCT 271@end table 272 273@item lumi_mask @var{float} (@emph{encoding,video}) 274Compress bright areas stronger than medium ones. 275 276@item tcplx_mask @var{float} (@emph{encoding,video}) 277Set temporal complexity masking. 278 279@item scplx_mask @var{float} (@emph{encoding,video}) 280Set spatial complexity masking. 281 282@item p_mask @var{float} (@emph{encoding,video}) 283Set inter masking. 284 285@item dark_mask @var{float} (@emph{encoding,video}) 286Compress dark areas stronger than medium ones. 287 288@item idct @var{integer} (@emph{decoding/encoding,video}) 289Select IDCT implementation. 290 291Possible values: 292@table @samp 293@item auto 294 295@item int 296 297@item simple 298 299@item simplemmx 300 301@item simpleauto 302Automatically pick a IDCT compatible with the simple one 303 304@item arm 305 306@item altivec 307 308@item sh4 309 310@item simplearm 311 312@item simplearmv5te 313 314@item simplearmv6 315 316@item simpleneon 317 318@item xvid 319 320@item faani 321floating point AAN IDCT 322@end table 323 324@item slice_count @var{integer} 325 326@item ec @var{flags} (@emph{decoding,video}) 327Set error concealment strategy. 328 329Possible values: 330@table @samp 331@item guess_mvs 332iterative motion vector (MV) search (slow) 333@item deblock 334use strong deblock filter for damaged MBs 335@item favor_inter 336favor predicting from the previous frame instead of the current 337@end table 338 339@item bits_per_coded_sample @var{integer} 340 341@item aspect @var{rational number} (@emph{encoding,video}) 342Set sample aspect ratio. 343 344@item sar @var{rational number} (@emph{encoding,video}) 345Set sample aspect ratio. Alias to @var{aspect}. 346 347@item debug @var{flags} (@emph{decoding/encoding,audio,video,subtitles}) 348Print specific debug info. 349 350Possible values: 351@table @samp 352@item pict 353picture info 354@item rc 355rate control 356@item bitstream 357 358@item mb_type 359macroblock (MB) type 360@item qp 361per-block quantization parameter (QP) 362@item dct_coeff 363 364@item green_metadata 365display complexity metadata for the upcoming frame, GoP or for a given duration. 366 367@item skip 368 369@item startcode 370 371@item er 372error recognition 373@item mmco 374memory management control operations (H.264) 375@item bugs 376 377@item buffers 378picture buffer allocations 379@item thread_ops 380threading operations 381@item nomc 382skip motion compensation 383@end table 384 385@item cmp @var{integer} (@emph{encoding,video}) 386Set full pel me compare function. 387 388Possible values: 389@table @samp 390@item sad 391sum of absolute differences, fast (default) 392@item sse 393sum of squared errors 394@item satd 395sum of absolute Hadamard transformed differences 396@item dct 397sum of absolute DCT transformed differences 398@item psnr 399sum of squared quantization errors (avoid, low quality) 400@item bit 401number of bits needed for the block 402@item rd 403rate distortion optimal, slow 404@item zero 4050 406@item vsad 407sum of absolute vertical differences 408@item vsse 409sum of squared vertical differences 410@item nsse 411noise preserving sum of squared differences 412@item w53 4135/3 wavelet, only used in snow 414@item w97 4159/7 wavelet, only used in snow 416@item dctmax 417 418@item chroma 419 420@end table 421 422@item subcmp @var{integer} (@emph{encoding,video}) 423Set sub pel me compare function. 424 425Possible values: 426@table @samp 427@item sad 428sum of absolute differences, fast (default) 429@item sse 430sum of squared errors 431@item satd 432sum of absolute Hadamard transformed differences 433@item dct 434sum of absolute DCT transformed differences 435@item psnr 436sum of squared quantization errors (avoid, low quality) 437@item bit 438number of bits needed for the block 439@item rd 440rate distortion optimal, slow 441@item zero 4420 443@item vsad 444sum of absolute vertical differences 445@item vsse 446sum of squared vertical differences 447@item nsse 448noise preserving sum of squared differences 449@item w53 4505/3 wavelet, only used in snow 451@item w97 4529/7 wavelet, only used in snow 453@item dctmax 454 455@item chroma 456 457@end table 458 459@item mbcmp @var{integer} (@emph{encoding,video}) 460Set macroblock compare function. 461 462Possible values: 463@table @samp 464@item sad 465sum of absolute differences, fast (default) 466@item sse 467sum of squared errors 468@item satd 469sum of absolute Hadamard transformed differences 470@item dct 471sum of absolute DCT transformed differences 472@item psnr 473sum of squared quantization errors (avoid, low quality) 474@item bit 475number of bits needed for the block 476@item rd 477rate distortion optimal, slow 478@item zero 4790 480@item vsad 481sum of absolute vertical differences 482@item vsse 483sum of squared vertical differences 484@item nsse 485noise preserving sum of squared differences 486@item w53 4875/3 wavelet, only used in snow 488@item w97 4899/7 wavelet, only used in snow 490@item dctmax 491 492@item chroma 493 494@end table 495 496@item ildctcmp @var{integer} (@emph{encoding,video}) 497Set interlaced dct compare function. 498 499Possible values: 500@table @samp 501@item sad 502sum of absolute differences, fast (default) 503@item sse 504sum of squared errors 505@item satd 506sum of absolute Hadamard transformed differences 507@item dct 508sum of absolute DCT transformed differences 509@item psnr 510sum of squared quantization errors (avoid, low quality) 511@item bit 512number of bits needed for the block 513@item rd 514rate distortion optimal, slow 515@item zero 5160 517@item vsad 518sum of absolute vertical differences 519@item vsse 520sum of squared vertical differences 521@item nsse 522noise preserving sum of squared differences 523@item w53 5245/3 wavelet, only used in snow 525@item w97 5269/7 wavelet, only used in snow 527@item dctmax 528 529@item chroma 530 531@end table 532 533@item dia_size @var{integer} (@emph{encoding,video}) 534Set diamond type & size for motion estimation. 535@table @samp 536@item (1024, INT_MAX) 537full motion estimation(slowest) 538@item (768, 1024] 539umh motion estimation 540@item (512, 768] 541hex motion estimation 542@item (256, 512] 543l2s diamond motion estimation 544@item [2,256] 545var diamond motion estimation 546@item (-1, 2) 547small diamond motion estimation 548@item -1 549funny diamond motion estimation 550@item (INT_MIN, -1) 551sab diamond motion estimation 552@end table 553 554@item last_pred @var{integer} (@emph{encoding,video}) 555Set amount of motion predictors from the previous frame. 556 557@item precmp @var{integer} (@emph{encoding,video}) 558Set pre motion estimation compare function. 559 560Possible values: 561@table @samp 562@item sad 563sum of absolute differences, fast (default) 564@item sse 565sum of squared errors 566@item satd 567sum of absolute Hadamard transformed differences 568@item dct 569sum of absolute DCT transformed differences 570@item psnr 571sum of squared quantization errors (avoid, low quality) 572@item bit 573number of bits needed for the block 574@item rd 575rate distortion optimal, slow 576@item zero 5770 578@item vsad 579sum of absolute vertical differences 580@item vsse 581sum of squared vertical differences 582@item nsse 583noise preserving sum of squared differences 584@item w53 5855/3 wavelet, only used in snow 586@item w97 5879/7 wavelet, only used in snow 588@item dctmax 589 590@item chroma 591 592@end table 593 594@item pre_dia_size @var{integer} (@emph{encoding,video}) 595Set diamond type & size for motion estimation pre-pass. 596 597@item subq @var{integer} (@emph{encoding,video}) 598Set sub pel motion estimation quality. 599 600@item me_range @var{integer} (@emph{encoding,video}) 601Set limit motion vectors range (1023 for DivX player). 602 603@item global_quality @var{integer} (@emph{encoding,audio,video}) 604 605@item slice_flags @var{integer} 606 607@item mbd @var{integer} (@emph{encoding,video}) 608Set macroblock decision algorithm (high quality mode). 609 610Possible values: 611@table @samp 612@item simple 613use mbcmp (default) 614@item bits 615use fewest bits 616@item rd 617use best rate distortion 618@end table 619 620@item rc_init_occupancy @var{integer} (@emph{encoding,video}) 621Set number of bits which should be loaded into the rc buffer before 622decoding starts. 623 624@item flags2 @var{flags} (@emph{decoding/encoding,audio,video,subtitles}) 625 626Possible values: 627@table @samp 628@item fast 629Allow non spec compliant speedup tricks. 630@item noout 631Skip bitstream encoding. 632@item ignorecrop 633Ignore cropping information from sps. 634@item local_header 635Place global headers at every keyframe instead of in extradata. 636@item chunks 637Frame data might be split into multiple chunks. 638@item showall 639Show all frames before the first keyframe. 640@item export_mvs 641Export motion vectors into frame side-data (see @code{AV_FRAME_DATA_MOTION_VECTORS}) 642for codecs that support it. See also @file{doc/examples/export_mvs.c}. 643@item skip_manual 644Do not skip samples and export skip information as frame side data. 645@item ass_ro_flush_noop 646Do not reset ASS ReadOrder field on flush. 647@end table 648 649@item export_side_data @var{flags} (@emph{decoding/encoding,audio,video,subtitles}) 650 651Possible values: 652@table @samp 653@item mvs 654Export motion vectors into frame side-data (see @code{AV_FRAME_DATA_MOTION_VECTORS}) 655for codecs that support it. See also @file{doc/examples/export_mvs.c}. 656@item prft 657Export encoder Producer Reference Time into packet side-data (see @code{AV_PKT_DATA_PRFT}) 658for codecs that support it. 659@item venc_params 660Export video encoding parameters through frame side data (see @code{AV_FRAME_DATA_VIDEO_ENC_PARAMS}) 661for codecs that support it. At present, those are H.264 and VP9. 662@item film_grain 663Export film grain parameters through frame side data (see @code{AV_FRAME_DATA_FILM_GRAIN_PARAMS}). 664Supported at present by AV1 decoders. 665@end table 666 667@item threads @var{integer} (@emph{decoding/encoding,video}) 668Set the number of threads to be used, in case the selected codec 669implementation supports multi-threading. 670 671Possible values: 672@table @samp 673@item auto, 0 674automatically select the number of threads to set 675@end table 676 677Default value is @samp{auto}. 678 679@item dc @var{integer} (@emph{encoding,video}) 680Set intra_dc_precision. 681 682@item nssew @var{integer} (@emph{encoding,video}) 683Set nsse weight. 684 685@item skip_top @var{integer} (@emph{decoding,video}) 686Set number of macroblock rows at the top which are skipped. 687 688@item skip_bottom @var{integer} (@emph{decoding,video}) 689Set number of macroblock rows at the bottom which are skipped. 690 691@item profile @var{integer} (@emph{encoding,audio,video}) 692 693Set encoder codec profile. Default value is @samp{unknown}. Encoder specific 694profiles are documented in the relevant encoder documentation. 695 696@item level @var{integer} (@emph{encoding,audio,video}) 697 698Possible values: 699@table @samp 700@item unknown 701 702@end table 703 704@item lowres @var{integer} (@emph{decoding,audio,video}) 705Decode at 1= 1/2, 2=1/4, 3=1/8 resolutions. 706 707@item mblmin @var{integer} (@emph{encoding,video}) 708Set min macroblock lagrange factor (VBR). 709 710@item mblmax @var{integer} (@emph{encoding,video}) 711Set max macroblock lagrange factor (VBR). 712 713@item skip_loop_filter @var{integer} (@emph{decoding,video}) 714@item skip_idct @var{integer} (@emph{decoding,video}) 715@item skip_frame @var{integer} (@emph{decoding,video}) 716 717Make decoder discard processing depending on the frame type selected 718by the option value. 719 720@option{skip_loop_filter} skips frame loop filtering, @option{skip_idct} 721skips frame IDCT/dequantization, @option{skip_frame} skips decoding. 722 723Possible values: 724@table @samp 725@item none 726Discard no frame. 727 728@item default 729Discard useless frames like 0-sized frames. 730 731@item noref 732Discard all non-reference frames. 733 734@item bidir 735Discard all bidirectional frames. 736 737@item nokey 738Discard all frames excepts keyframes. 739 740@item nointra 741Discard all frames except I frames. 742 743@item all 744Discard all frames. 745@end table 746 747Default value is @samp{default}. 748 749@item bidir_refine @var{integer} (@emph{encoding,video}) 750Refine the two motion vectors used in bidirectional macroblocks. 751 752@item keyint_min @var{integer} (@emph{encoding,video}) 753Set minimum interval between IDR-frames. 754 755@item refs @var{integer} (@emph{encoding,video}) 756Set reference frames to consider for motion compensation. 757 758@item trellis @var{integer} (@emph{encoding,audio,video}) 759Set rate-distortion optimal quantization. 760 761@item mv0_threshold @var{integer} (@emph{encoding,video}) 762@item compression_level @var{integer} (@emph{encoding,audio,video}) 763@item bits_per_raw_sample @var{integer} 764@item channel_layout @var{integer} (@emph{decoding/encoding,audio}) 765 766Possible values: 767@table @samp 768@end table 769@item request_channel_layout @var{integer} (@emph{decoding,audio}) 770 771Possible values: 772@table @samp 773@end table 774@item rc_max_vbv_use @var{float} (@emph{encoding,video}) 775@item rc_min_vbv_use @var{float} (@emph{encoding,video}) 776@item ticks_per_frame @var{integer} (@emph{decoding/encoding,audio,video}) 777 778@item color_primaries @var{integer} (@emph{decoding/encoding,video}) 779Possible values: 780@table @samp 781@item bt709 782BT.709 783@item bt470m 784BT.470 M 785@item bt470bg 786BT.470 BG 787@item smpte170m 788SMPTE 170 M 789@item smpte240m 790SMPTE 240 M 791@item film 792Film 793@item bt2020 794BT.2020 795@item smpte428 796@item smpte428_1 797SMPTE ST 428-1 798@item smpte431 799SMPTE 431-2 800@item smpte432 801SMPTE 432-1 802@item jedec-p22 803JEDEC P22 804@end table 805 806@item color_trc @var{integer} (@emph{decoding/encoding,video}) 807Possible values: 808@table @samp 809@item bt709 810BT.709 811@item gamma22 812BT.470 M 813@item gamma28 814BT.470 BG 815@item smpte170m 816SMPTE 170 M 817@item smpte240m 818SMPTE 240 M 819@item linear 820Linear 821@item log 822@item log100 823Log 824@item log_sqrt 825@item log316 826Log square root 827@item iec61966_2_4 828@item iec61966-2-4 829IEC 61966-2-4 830@item bt1361 831@item bt1361e 832BT.1361 833@item iec61966_2_1 834@item iec61966-2-1 835IEC 61966-2-1 836@item bt2020_10 837@item bt2020_10bit 838BT.2020 - 10 bit 839@item bt2020_12 840@item bt2020_12bit 841BT.2020 - 12 bit 842@item smpte2084 843SMPTE ST 2084 844@item smpte428 845@item smpte428_1 846SMPTE ST 428-1 847@item arib-std-b67 848ARIB STD-B67 849@end table 850 851@item colorspace @var{integer} (@emph{decoding/encoding,video}) 852Possible values: 853@table @samp 854@item rgb 855RGB 856@item bt709 857BT.709 858@item fcc 859FCC 860@item bt470bg 861BT.470 BG 862@item smpte170m 863SMPTE 170 M 864@item smpte240m 865SMPTE 240 M 866@item ycocg 867YCOCG 868@item bt2020nc 869@item bt2020_ncl 870BT.2020 NCL 871@item bt2020c 872@item bt2020_cl 873BT.2020 CL 874@item smpte2085 875SMPTE 2085 876@item chroma-derived-nc 877Chroma-derived NCL 878@item chroma-derived-c 879Chroma-derived CL 880@item ictcp 881ICtCp 882@end table 883 884@item color_range @var{integer} (@emph{decoding/encoding,video}) 885If used as input parameter, it serves as a hint to the decoder, which 886color_range the input has. 887Possible values: 888@table @samp 889@item tv 890@item mpeg 891MPEG (219*2^(n-8)) 892@item pc 893@item jpeg 894JPEG (2^n-1) 895@end table 896 897@item chroma_sample_location @var{integer} (@emph{decoding/encoding,video}) 898Possible values: 899@table @samp 900@item left 901 902@item center 903 904@item topleft 905 906@item top 907 908@item bottomleft 909 910@item bottom 911 912@end table 913 914@item log_level_offset @var{integer} 915Set the log level offset. 916 917@item slices @var{integer} (@emph{encoding,video}) 918Number of slices, used in parallelized encoding. 919 920@item thread_type @var{flags} (@emph{decoding/encoding,video}) 921Select which multithreading methods to use. 922 923Use of @samp{frame} will increase decoding delay by one frame per 924thread, so clients which cannot provide future frames should not use 925it. 926 927Possible values: 928@table @samp 929@item slice 930Decode more than one part of a single frame at once. 931 932Multithreading using slices works only when the video was encoded with 933slices. 934 935@item frame 936Decode more than one frame at once. 937@end table 938 939Default value is @samp{slice+frame}. 940 941@item audio_service_type @var{integer} (@emph{encoding,audio}) 942Set audio service type. 943 944Possible values: 945@table @samp 946@item ma 947Main Audio Service 948@item ef 949Effects 950@item vi 951Visually Impaired 952@item hi 953Hearing Impaired 954@item di 955Dialogue 956@item co 957Commentary 958@item em 959Emergency 960@item vo 961Voice Over 962@item ka 963Karaoke 964@end table 965 966@item request_sample_fmt @var{sample_fmt} (@emph{decoding,audio}) 967Set sample format audio decoders should prefer. Default value is 968@code{none}. 969 970@item pkt_timebase @var{rational number} 971 972@item sub_charenc @var{encoding} (@emph{decoding,subtitles}) 973Set the input subtitles character encoding. 974 975@item field_order @var{field_order} (@emph{video}) 976Set/override the field order of the video. 977Possible values: 978@table @samp 979@item progressive 980Progressive video 981@item tt 982Interlaced video, top field coded and displayed first 983@item bb 984Interlaced video, bottom field coded and displayed first 985@item tb 986Interlaced video, top coded first, bottom displayed first 987@item bt 988Interlaced video, bottom coded first, top displayed first 989@end table 990 991@item skip_alpha @var{bool} (@emph{decoding,video}) 992Set to 1 to disable processing alpha (transparency). This works like the 993@samp{gray} flag in the @option{flags} option which skips chroma information 994instead of alpha. Default is 0. 995 996@item codec_whitelist @var{list} (@emph{input}) 997"," separated list of allowed decoders. By default all are allowed. 998 999@item dump_separator @var{string} (@emph{input}) 1000Separator used to separate the fields printed on the command line about the 1001Stream parameters. 1002For example, to separate the fields with newlines and indentation: 1003@example 1004ffprobe -dump_separator " 1005 " -i ~/videos/matrixbench_mpeg2.mpg 1006@end example 1007 1008@item max_pixels @var{integer} (@emph{decoding/encoding,video}) 1009Maximum number of pixels per image. This value can be used to avoid out of 1010memory failures due to large images. 1011 1012@item apply_cropping @var{bool} (@emph{decoding,video}) 1013Enable cropping if cropping parameters are multiples of the required 1014alignment for the left and top parameters. If the alignment is not met the 1015cropping will be partially applied to maintain alignment. 1016Default is 1 (enabled). 1017Note: The required alignment depends on if @code{AV_CODEC_FLAG_UNALIGNED} is set and the 1018CPU. @code{AV_CODEC_FLAG_UNALIGNED} cannot be changed from the command line. Also hardware 1019decoders will not apply left/top Cropping. 1020 1021 1022@end table 1023 1024@c man end CODEC OPTIONS 1025 1026@ifclear config-writeonly 1027@include decoders.texi 1028@end ifclear 1029@ifclear config-readonly 1030@include encoders.texi 1031@end ifclear 1032