Audio and video codecs

Audio Codecs

General Audio Attributes

used when no other attributes are specified

Name	Type	Default	Description
b	int	128K	Set audio bitrate (in bits/s). Support unit prefixes such as K.
ar	int	0	Set audio sampling rate (in Hz)
flags	flags		bitexact - use only bitexact stuff (except (i)dct)
maxrate	int	0	Set max bitrate tolerance (in bits/s). Requires bufsize to be set.
minrate	int	0	Set min bitrate tolerance (in bits/s). Most useful in setting up a CBR encode. It is of little use elsewise.
bufsize	int	0	Set ratecontrol buffer size (in bits)

AAC (Advanced Audio Coding)

Configuration Parameter: aac

Additional attributes

Name	Type	Default	Description
stereo_mode	option_fixed	ms_off	Stereo coding method auto - Selected by the Encoder ms_off - Disable Mid/Side coding ms_force - Force Mid/Side for the whole frame if possible.
aac_coder	int	2	Set AAC encoder coding method. Possible values: 0 - twoloop, 1 - anmr, 2 - fast.
profile	option_fixed	unknown	Profile of AAC coding. Possible values: unknown, main, low, ssr, ltp, he, he_v2, ld, eld.

ATSC A/52A (AC-3)

Configuration Parameter: ac3

Additional attributes

Name	Type	Default	Description
profile	option_fixed	unknown	AC3 profile. Possible values: unknown, dts, dts_es, dts_96_24, dts_hd_hra, dts_hd_ma.
center_mixlev	double	0.594604	Center Mix Level. The amount of gain the decoder should apply to the center channel when downmixing to stereo. This field will only be written to the bitstream if a center channel is present. The value is specified as a scale factor.
surround_mixlev	double	0.500000	Surround Mix Level. The amount of gain the decoder should apply to the surround channel(s) when downmixing to stereo. This field will only be written to the bitstream if one or more surround channels are present. The value is specified as a scale factor.
mixing_level	int	-1	Mixing Level. Specifies peak sound pressure level (SPL) in the production environment when the mix was mastered. Valid values are 80 to 111, or -1 for unknown or not indicated. The default value is -1, but that value cannot be used if the Audio Production Information is written to the bitstream. Therefore, if the room_type option is not the default value, the mixing_level option must not be -1.
room_type	option_fixed		Room Type. Describes the equalization used during the final mixing session at the studio or on the dubbing stage. A large room is a dubbing stage with the industry standard X-curve equalization; a small room has flat equalization. This field will not be written to the bitstream if both the mixing_level option and the room_type option have the default values.
per_frame_metadata	bool	0	Allow Changing Metadata Per-Frame. Specifies if the encoder should check for changing metadata for each frame.
copyright	int	-1	Copyright Bit. Specifies whether a copyright exists for this audio.
dialnorm	int	-31	Dialogue Normalization. Indicates how far the average dialogue level of the program is below digital 100% full scale (0 dBFS). This parameter determines a level shift during audio reproduction that sets the average volume of the dialogue to a preset level. The goal is to match volume level between program sources. A value of -31dB will result in no volume level change, relative to the source volume, during audio reproduction. Valid values are whole numbers in the range -31 to -1, with -31 being the default.
dsur_mode	option_fixed		Dolby Surround Mode. Specifies whether the stereo signal uses Dolby Surround (Pro Logic). This field will only be written to the bitstream if the audio stream is stereo. Using this option does NOT mean the encoder will actually apply Dolby Surround processing. notindicated - Not Indicated (default) on - Dolby Surround Encoded off - Not Dolby Surround Encoded.
original	int	-1	Original Bit Stream Indicator. Specifies whether this audio is from the original source and not a copy.
dmix_mode	option_fixed		Preferred Stereo Downmix Mode. Allows the user to select either Lt/Rt (Dolby Surround) or Lo/Ro (normal stereo) as the preferred stereo downmix mode.
ltrt_cmixlev	double	-1.000000	Lt/Rt Center Mix Level. The amount of gain the decoder should apply to the center channel when downmixing to stereo in Lt/Rt mode.
ltrt_surmixlev	double	-1.000000	Lt/Rt Surround Mix Level. The amount of gain the decoder should apply to the surround channel(s) when downmixing to stereo in Lt/Rt mode.
loro_cmixlev	double	-1.000000	Lo/Ro Center Mix Level. The amount of gain the decoder should apply to the center channel when downmixing to stereo in Lo/Ro mode.
loro_surmixlev	double	-1.000000	Lo/Ro Surround Mix Level. The amount of gain the decoder should apply to the surround channel(s) when downmixing to stereo in Lo/Ro mode.
dsurex_mode	option_fixed	0	Dolby Surround EX Mode. Indicates whether the stream uses Dolby Surround EX (7.1 matrixed to 5.1). Using this option does NOT mean the encoder will actually apply Dolby Surround EX processing.
dheadphone_mode	option_fixed	0	Dolby Headphone Mode. Indicates whether the stream uses Dolby Headphone encoding (multi-channel matrixed to 2.0 for use with headphones). Using this option does NOT mean the encoder will actually apply Dolby Headphone processing.
ad_conv_type	option_fixed	0	A/D Converter Type. Indicates whether the audio has passed through HDCD A/D conversion.
stereo_rematrixing	bool	true	Stereo Rematrixing. Enables/Disables use of rematrixing for stereo input. This is an optional AC-3 feature that increases quality by selectively encoding the left/right channels as mid/side. This option is enabled by default, and it is highly recommended that it be left as enabled except for testing purposes.
channel_coupling	option_fixed	auto	Enables/Disables use of channel coupling, which is an optional AC-3 feature that increases quality by combining high frequency information from multiple channels into a single channel. The per-channel high frequency information is sent with less accuracy in both the frequency and time domains. This allows more bits to be used for lower frequencies while preserving enough information to reconstruct the high frequencies. This option is enabled by default for the floating-point encoder and should generally be left as enabled except for testing purposes or to increase encoding speed.
cpl_start_band	option_fixed	auto	Coupling Start Band. Sets the channel coupling start band, from 1 to 15. If a value higher than the bandwidth is used, it will be reduced to 1 less than the coupling end band. If auto is used, the start band will be determined by the encoder based on the bit rate, sample rate, and channel layout. This option has no effect if channel coupling is disabled.

ATSC A/52A (AC-3) Fixed

Configuration Parameter: ac3_fixed

Additional attributes

Name	Type	Default	Description
profile	option_fixed	unknown	AC3 profile. Possible values: unknown, dts, dts_es, dts_96_24, dts_hd_hra, dts_hd_ma.
center_mixlev	double	0.594604	Center Mix Level. The amount of gain the decoder should apply to the center channel when downmixing to stereo. This field will only be written to the bitstream if a center channel is present. The value is specified as a scale factor.
surround_mixlev	double	0.500000	Surround Mix Level. The amount of gain the decoder should apply to the surround channel(s) when downmixing to stereo. This field will only be written to the bitstream if one or more surround channels are present. The value is specified as a scale factor.
mixing_level	int	-1	Mixing Level. Specifies peak sound pressure level (SPL) in the production environment when the mix was mastered. Valid values are 80 to 111, or -1 for unknown or not indicated. The default value is -1, but that value cannot be used if the Audio Production Information is written to the bitstream. Therefore, if the room_type option is not the default value, the mixing_level option must not be -1.
copyright	int	-1	Copyright Bit. Specifies whether a copyright exists for this audio.
dsur_mode	option_fixed		Dolby Surround Mode. Specifies whether the stereo signal uses Dolby Surround (Pro Logic). This field will only be written to the bitstream if the audio stream is stereo. Using this option does NOT mean the encoder will actually apply Dolby Surround processing. notindicated - Not Indicated (default) on - Dolby Surround Encoded off - Not Dolby Surround Encoded.
ltrt_cmixlev	double	-1.000000	Lt/Rt Center Mix Level. The amount of gain the decoder should apply to the center channel when downmixing to stereo in Lt/Rt mode.
ltrt_surmixlev	double	-1.000000	Lt/Rt Surround Mix Level. The amount of gain the decoder should apply to the surround channel(s) when downmixing to stereo in Lt/Rt mode.
loro_cmixlev	double	-1.000000	Lo/Ro Center Mix Level. The amount of gain the decoder should apply to the center channel when downmixing to stereo in Lo/Ro mode.
loro_surmixlev	double	-1.000000	Lo/Ro Surround Mix Level. The amount of gain the decoder should apply to the surround channel(s) when downmixing to stereo in Lo/Ro mode.

ALAC (Apple Lossless Audio Codec)

Configuration Parameter: alac

ATSC A/52 E-AC-3

Configuration Parameter: eac3

Additional attributes

Name	Type	Default	Description
profile	option_fixed	unknown	Profile name. Possible values: unknown, dts, dts_es, dts_96_24, dts_hd_hra, dts_hd_ma.
mixing_level	int	-1	Mixing Level. Specifies peak sound pressure level (SPL) in the production environment when the mix was mastered. Valid values are 80 to 111, or -1 for unknown or not indicated. The default value is -1, but that value cannot be used if the Audio Production Information is written to the bitstream. Therefore, if the room_type option is not the default value, the mixing_level option must not be -1.
copyright	int	-1	Copyright Bit. Specifies whether a copyright exists for this audio.
dsur_mode	option_fixed		Dolby Surround Mode. Specifies whether the stereo signal uses Dolby Surround (Pro Logic). This field will only be written to the bitstream if the audio stream is stereo. Using this option does NOT mean the encoder will actually apply Dolby Surround processing. notindicated - Not Indicated (default) on - Dolby Surround Encoded off - Not Dolby Surround Encoded.
ltrt_cmixlev	double	-1.000000	Lt/Rt Center Mix Level. The amount of gain the decoder should apply to the center channel when downmixing to stereo in Lt/Rt mode.
ltrt_surmixlev	double	-1.000000	Lt/Rt Surround Mix Level. The amount of gain the decoder should apply to the surround channel(s) when downmixing to stereo in Lt/Rt mode.
loro_cmixlev	double	-1.000000	Lo/Ro Center Mix Level. The amount of gain the decoder should apply to the center channel when downmixing to stereo in Lo/Ro mode.
loro_surmixlev	double	-1.000000	Lo/Ro Surround Mix Level. The amount of gain the decoder should apply to the surround channel(s) when downmixing to stereo in Lo/Ro mode.

FLAC (Free Lossless Audio Codec)

Configuration Parameter: flac

Additional attributes

Name	Type	Default	Description
lpc_coeff_precision	int	15	Sets the LPC coefficient precision, valid values are from 1 to 15, 15 is the default.
lpc_type	option_fixed		Sets the first stage LPC algorithm. Possible values: none, fixed, levinson, cholesky.
lpc_passes	int	-1	Number of passes to use for Cholesky factorization during LPC analysis.
min_partition_order	int	-1	Minimal partition order.
max_partition_order	int	-1	Maximal partition order.
prediction_order_method	option_fixed		Search method for selecting prediction order.
predm			Search method for selecting prediction order. Possible values: estimation, 2level, 4level, 8level, search, log.
ch_mode	option_fixed	auto	Stereo decorrelation mode. Possible values: auto, indep, left_side, right_side, mid_side.

MP2 (MPEG audio layer 2)

Configuration Parameter: mp2

Ogg Vorbis

Configuration Parameter: libvorbis

(Uncompressed) PCM 32-bit floating point little-endian

Configuration Parameter: pcm_f32le

(Uncompressed) PCM signed 16-bit little-endian

Configuration Parameter: pcm_s16le

(Uncompressed) PCM D-Cinema audio signed 24-bit

Configuration Parameter: pcm_s24daud

(Uncompressed) PCM signed 24-bit little-endian

Configuration Parameter: pcm_s24le

(Uncompressed) PCM signed 32-bit little-endian

Configuration Parameter: pcm_s32le

ADPCM IMA QuickTime

Configuration Parameter: adpcm_ima_qt

ADPCM Microsoft

Configuration Parameter: adpcm_ms

MP3 Lame (MPEG audio layer 3)

Configuration Parameter: libmp3lame

Video Codecs

General Video Attributes

used when no other attributes are specified

Name	Type	Default	Description
b	int	5M	Set video bitrate (in bits/s). Support unit prefixes such as K or M.
bt	int	4000000	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.
flags	flags		ildct - use interlaced dct low_delay - force low delay ilme - interlaced motion estimation cgop - closed GOP
size	string		Resolution of video. Format: WIDTHxHEIGHT.
ar	option		Aspect ratio of video.
ar_type	option_fixed		Type of video's aspect ratio.
g	int	-1	Keyframe interval, also known as GOP length. This determines the maximum distance between I-frames. Very high GOP lengths will result in slightly more efficient compression, but will make seeking in the video somewhat more difficult.
qcomp	double	0.500000	Video quantizer scale compression (VBR). Constant of ratecontrol equation. Recommended range for default rc_eq: 0.0-1.0
qmin	int	-1	Min video quantizer scale (VBR).
qmax	int	-1	Max video quantizer scale (VBR).
qdiff	int	3	Max difference between the quantizer scale (VBR).
bf	int	0	This parameter simply serves to limit the max number of B-frames. Note that Baseline Profile, such as that used by iPods, does not support B-frames. Recommended default: 16
b_strategy	int	0	Strategy to choose between I/P/B-frames. 0: Very fast; 1: Fast, a good balance between speed and quality; 2: A much slower but more accurate B-frame decision mode that correctly detects fades and generally gives considerably better quality.
maxrate	int	0	Specifies the maximum bitrate at any point in the video. Requires the VBV buffersize to be set. This option is generally used when encoding for a piece of hardware with bitrate limitations.
minrate	int	0	Set min bitrate tolerance (in bits/s). Most useful in setting up a CBR encode. It is of little use elsewise.
bufsize	int	0	Set ratecontrol buffer size (in bits). Depends on the profile level of the video being encoded. Set only if you're encoding for a hardware device.
i_qfactor	double	-0.800000	Qscale difference between I-frames and P-frames.
dct	option_fixed	auto	DCT algorithm auto - autoselect a good one (default) fastint - fast integer int - accurate integer mmx - MMX altivec - altivec faan - floating point AAN DCT
cmp	option_fixed	sad	Full pel motion estimation compare function.
cmp_func			sse - sum of squared errors satd - sum of absolute Hadamard transformed differences dct - sum of absolute DCT transformed differences bit - number of bits needed for the block rd - rate distortion optimal, slow zero - 0 vsad - sum of absolute vertical differences vsse - sum of squared vertical differences nsse - noise preserving sum of squared differences w53 - 5/3 wavelet, only used in snow w97 - 9/7 wavelet, only used in snow dctmax - DCT max chroma - Chroma
subq	int	8	Sub pel motion estimation quality.
me_range	int	0	MErange controls the max range of the motion search.
coder	option_fixed	vlc	ac - arithmetic coder raw - raw (no encoding) rle - run-length coder deflate - deflate-based coder
sc_threshold	int	0	Adjusts the sensitivity of codec's scenecut detection.
lmin	int	236	Min lagrange factor (VBR).
lmax	int	3658	Max lagrange factor (VBR).
rc_init_occupancy	int	0	Number of bits which should be loaded into the rc buffer before decoding starts.
threads	option_fixed		Detect a good number of threads.
dc	int	0	Intra DC Precision indicates the number of bits for quantized DC coefficients of intra-coded blocks; it takes one of the values of 8, 9, 10, or 11 bits. The more bits are used, the more precise quantization is achieved.
tag	string		Codec's tag (for example, 'xvid').
scaling_quality	string	auto	Scaling quality for video encoding.
refs	int	1	Reference frames to consider for motion compensation.
trellis	int	0	0: disabled; 1: enabled only on the final encode of a MB; 2: enabled on all mode decisions. The main decision made in quantization is which coefficients to round up and which to round down. Trellis chooses the optimal rounding choices for the maximum rate-distortion score, to maximize PSNR relative to bitrate.
timecode_frame_start	int64	-1	GOP timecode frame start number, in non drop frame format.
rc_max_vbv_use	double	0.000000	Maximal rate control of video buffer verifier's usage.
rc_min_vbv_use	double	3.000000	Minimal rate control of video buffer verifier's usage.
slices	int	0	Number of slices, used in parallelized encoding.
top	int		Field order for interlaced files (-1 - auto, 0 - bottom first, 1 - top first).
thread_type	flags	+slice+frame	Select multithreading type slice - Slice frame - Frame

Uncompressed 4:2:2 8bit

Configuration Parameter: rawvideo

Uncompressed 4:2:2 10bit

Configuration Parameter: v210

DV Video / DVCPRO-HD

Configuration Parameter: dvvideo

Additional attributes

Name	Type	Default	Description
dv_format	option_fixed	auto	Format for DV codec. Possible values: dvsd, dv25, dv50, dvhd. Note: x64 version support dvsd, dv25 only.

Intel QuickSync H.264 Encoder

Configuration Parameter: q264

Additional attributes

Name	Type	Default	Description
b	int	5M	The average bit rate in bps is the target bit rate used for VBR rate control.
quality	string		Quality of captured video. Possible values: from 1 (fast capturing, minimal quality) to 7 (maximal quality, slow capturing).
g	int	15	This is the IDR period for H264.
profile	option_fixed	Auto	Set the profile.
level	option_fixed	Auto	Sets the level flag in the output bitstream.
rc_type	option_fixed	quality	The rate control type.
maxrate	int	0	The maximum bit rate in bps is the peak bit rate used for VBR rate control.
bufsize	int	0	Set ratecontrol buffer size (in bits). Depends on the profile level of the video being encoded. Set only if you're encoding for a hardware device.
initialdelay	int	0	Specifies the initial delay in bits. Set 0 to use the default initial delay.
bf	int	1	This sets the distance of one P picture from the previous P picture. e.g. for IBBPBBP, set the value as 3.
ref_frames	int	0	Number of reference frames; if NumRefFrame = 0, this parameter is not specified.
cavlc	option_fixed	false	Enable/disable Context-adaptive variable-length coding mode.
size	string		Resolution of video. Format: WIDTHxHEIGHT.
icq_quality	int	25	Quality of intelligent constant quality algorithm. Possible values: from 1 (the best quality) to 51.
accuracy	int	100	Determines quality of complex scenes in AVBR mode.
convergence	int	0	Determines quality of complex scenes in AVBR mode.
qpi	int	22	Determines quality in CQP mode.
qpb	int	22	Determines quality in CQP mode.
qpp	int	22	Determines quality in CQP mode.
force_gpu	int	-2	Force Specified GPU encoder (0 - HW mode (first suitable HW device), -1 - SW mode, -2 - Auto HW/SW mode, 1..4 - Use specified HW device).
use_vpp	bool	false	Use Intel VPP for frame conversion and scaling.

Intel QuickSync SW H.264 Encoder

Configuration Parameter: q264sw

Additional attributes

Name	Type	Default	Description
b	int	5M	The average bit rate in bps is the target bit rate used for VBR rate control.
quality	string		Quality of captured video. Possible values: from 1 (fast capturing, minimal quality) to 7 (maximal quality, slow capturing).
g	int	15	This is the IDR period for H264.
profile	option_fixed	Auto	Set the profile.
level	option_fixed	Auto	Sets the level flag in the output bitstream.
rc_type	option_fixed	quality	The rate control type.
maxrate	int	0	The maximum bit rate in bps is the peak bit rate used for VBR rate control.
bufsize	int	0	Set ratecontrol buffer size (in bits). Depends on the profile level of the video being encoded. Set only if you're encoding for a hardware device.
initialdelay	int	0	Specifies the initial delay in bits. Set 0 to use the default initial delay.
bf	int	1	This sets the distance of one P picture from the previous P picture. e.g. for IBBPBBP, set the value as 3.
ref_frames	int	0	Number of reference frames; if NumRefFrame = 0, this parameter is not specified.
cavlc	option_fixed	false	Enable/disable Context-adaptive variable-length coding mode.
size	string		Resolution of video. Format: WIDTHxHEIGHT.
icq_quality	int	25	Quality of intelligent constant quality algorithm. Possible values: from 1 (the best quality) to 51.
accuracy	int	100	Determines quality of complex scenes in AVBR mode.
convergence	int	0	Determines quality of complex scenes in AVBR mode.
qpi	int	22	Determines quality in CQP mode.
qpb	int	22	Determines quality in CQP mode.
qpp	int	22	Determines quality in CQP mode.
use_vpp	bool	false	Use Intel VPP for frame conversion and scaling.

Intel QuickSync HW H.264 Encoder

Configuration Parameter: q264hw

Additional attributes

Name	Type	Default	Description
b	int	5M	The average bit rate in bps is the target bit rate used for VBR rate control.
gpu_memory	bool	false	Frames are stored in GPU memory.
quality	string	7	Quality of captured video. Possible values: from 1 (fast capturing, minimal quality) to 7 (maximal quality, slow capturing).
g	int	15	This is the IDR period for H264.
profile	option_fixed	Auto	Set the profile.
level	option_fixed	Auto	Sets the level flag in the output bitstream.
rc_type	option_fixed	quality	The rate control type.
maxrate	int	0	The maximum bit rate in bps is the peak bit rate used for VBR rate control.
bufsize	int	0	Set ratecontrol buffer size (in bits). Depends on the profile level of the video being encoded. Set only if you're encoding for a hardware device.
initialdelay	int	0	Specifies the initial delay in bits. Set 0 to use the default initial delay.
bf	int	1	This sets the distance of one P picture from the previous P picture. e.g. for IBBPBBP, set the value as 3.
ref_frames	int	0	Number of reference frames; if NumRefFrame = 0, this parameter is not specified.
cavlc	option_fixed	false	Enable/disable Context-adaptive variable-length coding mode.
size	string		Resolution of video. Format: WIDTHxHEIGHT.
icq_quality	int	25	Quality of intelligent constant quality algorithm. Possible values: from 1 (the best quality) to 51.
accuracy	int	100	Determines quality of complex scenes in AVBR mode.
convergence	int	0	Determines quality of complex scenes in AVBR mode.
qpi	int	22	Determines quality in CQP mode.
qpb	int	22	Determines quality in CQP mode.
qpp	int	22	Determines quality in CQP mode.
force_gpu	int	0	Force Specified GPU device for encode (0 - first suitable HW device, 1..4 - Use specified HW device).
use_vpp	bool	false	Use Intel VPP for frame conversion and scaling.

Intel VPL/MSDK H.264 Encoder

Configuration Parameter: h264_qsv

Additional attributes

Name	Type	Default	Description
preset	option_fixed		Change options to trade off compression efficiency against encoding speed
forced_idr	bool	false	Forcing I frames as IDR frames
low_power	bool	auto	Enable low power mode(experimental: many limitations by mfx version, BRC modes, etc.)
rdo	int	-1	Enable rate distortion optimization (from -1 to 1)
max_frame_size	int	-1	Maximum encoded frame size in bytes (from -1 to INT_MAX)
max_frame_size_i	int	-1	Maximum encoded I frame size in bytes (from -1 to INT_MAX)
max_frame_size_p	int	-1	Maximum encoded P frame size in bytes (from -1 to INT_MAX)
max_slice_size	int	-1	Maximum encoded slice size in bytes (from -1 to INT_MAX)
bitrate_limit	int	-1	MB level bitrate control (from -1 to 1)
mbbrc	int	-1	The maximum bit rate in bps is the peak bit rate used for VBR rate control.
extbrc	int	-1	Extended bitrate control (from -1 to 1)
adaptive_i	int	-1	Adaptive I-frame placement (from -1 to 1)
adaptive_b	int	-1	Adaptive B-frame placement (from -1 to 1)
low_delay_brc	bool	auto	Allow to strictly obey avg frame size
max_qp_i	int	-1	Maximum video quantizer scale for I frame (from -1 to 51)
min_qp_i	int	-1	Minimum video quantizer scale for I frame (from -1 to 51)
max_qp_p	int	-1	Maximum video quantizer scale for P frame (from -1 to 51)
min_qp_p	int	-1	Minimum video quantizer scale for P frame (from -1 to 51)
max_qp_b	int	-1	Maximum video quantizer scale for B frame (from -1 to 51)
min_qp_b	int	-1	Minimum video quantizer scale for B frame (from -1 to 51)
scenario	option_fixed	unknown	A hint to encoder about the scenario for the encoding session
avbr_accuracy	int	0	Accuracy of the AVBR ratecontrol (unit of tenth of percent) (from 0 to 65535)
avbr_convergence	int	0	Convergence of the AVBR ratecontrol (unit of 100 frames) (from 0 to 65535)
skip_frame	option_fixed	no_skip	Allow frame skipping
dual_gfx	option_fixed	off	Prefer processing on both iGfx and dGfx simultaneously
cavlc	bool	false	Enable CAVLC
vcm	bool	false	Use the video conferencing mode ratecontrol
idr_interval	int	0	Distance (in I-frames) between IDR frames (from 0 to INT_MAX)
pic_timing_sei	bool	true	Insert picture timing SEI with pic_struct_syntax element
single_sei_nal_unit	int	-1	Put all the SEI messages into one NALU (from -1 to 1)
max_dec_frame_buffering	int	0	Maximum number of frames buffered in the DPB (from 0 to 65535)
look_ahead	bool	false	Use VBR algorithm with look ahead
look_ahead_depth	int	0	Depth of look ahead in number frames (from 0 to 100)
look_ahead_downsampling	option_fixed	unknown	Downscaling factor for the frames saved for the lookahead analysis
int_ref_type	option	-1	Intra refresh type. B frames should be set to 0
int_ref_cycle_size	int	-1	Number of frames in the intra refresh cycle (from -1 to 65535)
int_ref_qp_delta	int	-32768	QP difference for the refresh MBs (from -32768 to 32767)
recovery_point_sei	int	-1	Insert recovery point SEI messages (from -1 to 1) (default -1)
int_ref_cycle_dist	int	-1	Distance between the beginnings of the intra-refresh cycles in frames (from -1 to 32767)
profile	option	unknown	Used profile
a53cc	bool	true	Use A53 Closed Captions (if available)
aud	bool	false	Insert the Access Unit Delimiter NAL
repeat_pps	bool	false	Repeat pps for every frame

Intel QuickSync HEVC Encoder

Configuration Parameter: q265hw

Additional attributes

Name	Type	Default	Description
rc_type	option_fixed	vbr	The rate control type
bf	int		This sets the distance of one P picture from the previous P picture. e.g. for IBBPBBP, set the value as 3.
async_depth	int	4	Maximum processing parallelism.
avbr_accuracy	int	0	Accuracy of the AVBR ratecontrol.
avbr_convergence	int	0	Convergence of the AVBR ratecontrol.
preset	option	medium	This option itemizes a range of choices from veryfast (best speed) to veryslow (best quality).
vcm	int	0	Use the video conferencing mode ratecontrol.
rdo	int	-1	Enable rate distortion optimization.
max_frame_size	int	-1	Maximum encoded frame size in bytes.
max_slice_size	int	-1	Maximum encoded slice size in bytes.
bitrate_limit	int	-1	Toggle bitrate limitations.
mbbrc	int	-1	MB level bitrate control.
extbrc	int	-1	Extended bitrate control.
adaptive_i	int	-1	Adaptive I-frame placement.
adaptive_b	int	-1	Adaptive B-frame placement.
b_strategy	int	-1	Strategy to choose between I/P/B-frames.
idr_interval	option		Distance (in I-frames) between IDR frames begin_only - Output an IDR-frame only at the beginning of the stream.
load_plugin	option	hevc_hw	A user plugin to load in an internal session.
load_plugins	string		A :-separate list of hexadecimal plugin UIDs to load in an internal session.
profile	option	unknown	Possible values: unknown, main, main10, mainsp.

Intel VPL/MSDK HEVC Encoder

Configuration Parameter: hevc_qsv

Additional attributes

Name	Type	Default	Description
async_depth	int	4	Maximum processing parallelism (from 1 to INT_MAX)
preset	option_fixed		Change options to trade off compression efficiency against encoding speed
forced_idr	bool	false	Forcing I frames as IDR frames
low_power	bool	auto	Enable low power mode(experimental: many limitations by mfx version, BRC modes, etc.)
rdo	int	-1	Enable rate distortion optimization (from -1 to 1)
max_frame_size	int	-1	Maximum encoded frame size in bytes (from -1 to INT_MAX)
max_frame_size_i	int	-1	Maximum encoded I frame size in bytes (from -1 to INT_MAX)
max_frame_size_p	int	-1	Maximum encoded P frame size in bytes (from -1 to INT_MAX)
max_slice_size	int	-1	Maximum encoded slice size in bytes (from -1 to INT_MAX)
bitrate_limit	int	-1	MB level bitrate control (from -1 to 1)
mbbrc	int	-1	The maximum bit rate in bps is the peak bit rate used for VBR rate control.
extbrc	int	-1	Extended bitrate control (from -1 to 1)
p_strategy	int	0	Enable P-pyramid: 0-default 1-simple 2-pyramid (bf need to be set to 0).
b_strategy	int	-1	Strategy to choose between I/P/B-frames (from -1 to 1)
low_delay_brc	bool	auto	Allow to strictly obey avg frame size
max_qp_i	int	-1	Maximum video quantizer scale for I frame (from -1 to 51)
min_qp_i	int	-1	Minimum video quantizer scale for I frame (from -1 to 51)
max_qp_p	int	-1	Maximum video quantizer scale for P frame (from -1 to 51)
min_qp_p	int	-1	Minimum video quantizer scale for P frame (from -1 to 51)
max_qp_b	int	-1	Maximum video quantizer scale for B frame (from -1 to 51)
min_qp_b	int	-1	Minimum video quantizer scale for B frame (from -1 to 51)
adaptive_i	int	-1	Adaptive I-frame placement (from -1 to 1)
adaptive_b	int	-1	Adaptive B-frame placement (from -1 to 1)
scenario	option_fixed	unknown	A hint to encoder about the scenario for the encoding session
avbr_accuracy	int	0	Accuracy of the AVBR ratecontrol (unit of tenth of percent) (from 0 to 65535)
avbr_convergence	int	0	Convergence of the AVBR ratecontrol (unit of 100 frames) (from 0 to 65535)
skip_frame	option_fixed	no_skip	Allow frame skipping
dual_gfx	option_fixed	off	Prefer processing on both iGfx and dGfx simultaneously
idr_interval	int	0	Distance (in I-frames) between IDR frames (from 0 to INT_MAX)
load_plugins	option_fixed	hevc_hw	A user plugin to load in an internal session
look_ahead_depth	int	0	Depth of look ahead in number frames (from 0 to 100)
profile	option	unknown	Used profile
tier	option	high	Set the encoding tier (only level >= 4 can support high tier)
gpb	bool	true	1: GPB (generalized P/B frame); 0: regular P frame
tile_cols	int	0	Number of columns for tiled encoding (from 0 to 65535)
tile_rows	int	0	Number of rows for tiled encoding (from 0 to 65535)
recovery_point_sei	int	-1	Insert recovery point SEI messages (from -1 to 1) (default -1)
aud	bool	false	Insert the Access Unit Delimiter NAL
pic_timing_sei	bool	true	Insert picture timing SEI with pic_struct_syntax element
transform_skip	int	-1	Turn this option ON to enable transformskip (from -1 to 1)
int_ref_type	option	-1	Intra refresh type. B frames should be set to 0
int_ref_cycle_size	int	-1	Number of frames in the intra refresh cycle (from -1 to 65535)
int_ref_qp_delta	int	-32768	QP difference for the refresh MBs (from -32768 to 32767)
int_ref_cycle_dist	int	-1	Distance between the beginnings of the intra-refresh cycles in frames (from -1 to 32767)

Intel VPL/MSDK AV1 Encoder

Configuration Parameter: av1_qsv

'ffmpeg_av1_qsv.enable' property enabled is required!

Additional attributes

Name	Type	Default	Description
async_depth	int	4	Maximum processing parallelism (from 1 to INT_MAX)
preset	option_fixed		Change options to trade off compression efficiency against encoding speed
forced_idr	bool	false	Forcing I frames as IDR frames
low_power	bool	auto	Enable low power mode(experimental: many limitations by mfx version, BRC modes, etc.)
b_strategy	int	-1	Strategy to choose between I/P/B-frames (from -1 to 1)
adaptive_i	int	-1	Adaptive I-frame placement (from -1 to 1)
adaptive_b	int	-1	Adaptive B-frame placement (from -1 to 1)
extbrc	int	-1	Extended bitrate control (from -1 to 1)
low_delay_brc	bool	auto	Allow to strictly obey avg frame size
max_frame_size	int	-1	Maximum encoded frame size in bytes (from -1 to INT_MAX)
max_frame_size_i	int	-1	Maximum encoded I frame size in bytes (from -1 to INT_MAX)
max_frame_size_p	int	-1	Maximum encoded P frame size in bytes (from -1 to INT_MAX)
profile	option	unknown	Used profile
tile_cols	int	0	Number of columns for tiled encoding (from 0 to 65535)
tile_rows	int	0	Number of rows for tiled encoding (from 0 to 65535)
look_ahead_depth	int	0	Depth of look ahead in number frames (from 0 to 100)

NVIDIA NVEnc H.264 Encoder

Configuration Parameter: n264

Additional attributes

Name	Type	Default	Description
b	int	5M	The average bit rate in bps is the target bit rate used for rate control.
g	int	15	This is the IDR period.
bf	int	1	This sets the distance of one P picture from the previous P picture. e.g. for IBBPBBP, set the value as 3.
rc_type	option_fixed	Auto	The rate control type.
preset	option_fixed	Auto	Codec Preset - if specified, some properties below ignored.
tuning_info	option_fixed		Codec Tuning Info - if specified, some properties below ignored.
profile	option_fixed	Auto	Codec Profile.
level	option_fixed	Auto	Sets the level flag in the output bitstream.
maxrate	int	0	The maximum bit rate in bps is the peak bit rate used for VBR rate control.
size	string		Resolution of video. Format: WIDTHxHEIGHT.
ar	option		Aspect ratio of video.
ar_type	option_fixed		Type of video's aspect ratio.
bufsize	int	0	Specifies the VBV(HRD) buffer size. in bits. Set 0 to use the default VBV buffer size.
initialdelay	int	0	Specifies the VBV(HRD) initial delay in bits. Set 0 to use the default VBV initial delay.
enableAQ	option_fixed	true	Set this to TRUE to enable adaptive quantization.
intraRefreshPeriod	int	0	Specifies the interval between successive intra refresh if intraRefreshCount is set.
intraRefreshCount	int	0	Specifies the length of intra refresh in number of frames for periodic intra refresh. This value should be smaller than intraRefreshPeriod.
disable_cabac	option_fixed	false	Enable or disable CABAC.
mvprecision	option_fixed	Auto	Specifies the desired motion vector prediction precision.
disable_sps_pps	option_fixed	false	Disable writing of Sequence and Picture parameter for every IDR frame.
separateColourPlaneFlag	option_fixed	false	Set 'true' to enable 4:4:4 separate colour planes.
deblock	option_fixed	1	Specifies the deblocking filter mode.
enableTemporalSVC	option_fixed	false	Set to 'true' to enable SVC temporal.
hierarchicalPFrames	option_fixed	false	Set to 'true' to enable hierarchical PFrames.
hierarchicalBFrames	option_fixed	false	Set to 'true' to enable hierarchical BFrames.
outputBufferingPeriodSEI	option_fixed	true	Set 'true' to write SEI buffering period syntax in the bitstream.
outputPictureTimingSEI	option_fixed	true	Set 'true' to write SEI picture timing syntax in the bitstream.
outputFramePackingSEI	option_fixed	true	Set 'true' to enable writing of frame packing arrangement SEI messages to bitstream.
outputRecoveryPointSEI	option_fixed	true	Set'true' to enable writing of recovery point SEI message.
numTemporalLayers	int		Specifies max temporal layers to be used for hierarchical coding. Valid value range is [1,10].
outputAUD	option_fixed	true	Set 'true' to write Access Unit Delimiter syntax.
maxNumRefFrames	int		Specifies the DPB size used for encoding. Setting it to 0 will let driver use the default dpb size. The low latency application which wants to invalidate reference frame as an error resilience tool is recommended to use a large DPB size so that the encoder can keep old reference frames which can be used if recent.
ltrNumFrames	int		Specifies the maximum number of long term references can be used for prediction.
ltrTrustMode	option_fixed		Specifies the LTR operating mode. Set to 'false' to disallow encoding using LTR frames until later specified. Set to 'true' to allow encoding using LTR frames unless later invalidated.
enableConstrainedEncoding	option_fixed		Set this to 1 to enable constrainedFrame encoding where each slice in the constarined picture is independent of other slices.
adaptiveTransformMode	option_fixed		Enable the AdaptiveTransform Mode.
fmoMode	option_fixed		Enable the FMO Mode.
interlace	option_fixed	Auto	Interlace type.
output.444	option_fixed	false	Enable or disable 444 encoding.
qpi	int	25	Determines I-frame quality in CQP mode.
qpp	int	28	Determines P-frame quality in CQP mode.
qpb	int	31	Determines B-frame quality in CQP mode.
targetQuality	int	0	Set target quality level (0 to 51, 0 means automatic) for constant quality mode in VBR rate control.
lowDelayKeyFrameScale	int	0	Specifies the Scene Change frame size increase allowed in case of single frame VBV and CBR (from 0 to 255).
enableFillerDataInsertion	int	0	Set to 1 in case the bitrate needs to be strictly adhered to.
force_gpu	int	0	Force Specified GPU device for encode (-1 - first suitable HW device, 0..3 - Use specified HW device).

NVIDIA NVEnc H.264 Lossless Encoder

Configuration Parameter: l264

Additional attributes

Name	Type	Default	Description
preset	option_fixed	lossless	Codec Preset
size	string		Resolution of video. Format: WIDTHxHEIGHT.
ar	option		Aspect ratio of video.
ar_type	option_fixed		Type of video's aspect ratio.
disable_sps_pps	option_fixed	false	Disable writing of Sequence and Picture parameter for every IDR frame.
outputBufferingPeriodSEI	option_fixed	true	Set 'true' to write SEI buffering period syntax in the bitstream.
outputPictureTimingSEI	option_fixed	true	Set 'true' to write SEI picture timing syntax in the bitstream.
outputFramePackingSEI	option_fixed	true	Set 'true' to enable writing of frame packing arrangement SEI messages to bitstream.
outputRecoveryPointSEI	option_fixed	true	Set'true' to enable writing of recovery point SEI message.
outputAUD	option_fixed	true	Set 'true' to write Access Unit Delimiter syntax.
output.444	option_fixed	false	Enable or disable 444 encoding.

NVIDIA NVEnc H.265 (HEVC) Encoder

Configuration Parameter: n265

Additional attributes

Name	Type	Default	Description
b	int	5M	The average bit rate in bps is the target bit rate used for rate control.
g	int	15	This is the IDR period.
bf	int	1	This sets the distance of one P picture from the previous P picture. e.g. for IBBPBBP, set the value as 3.
rc_type	option_fixed	Auto	The rate control type.
preset	option_fixed	Auto	Codec Preset - if specified, some properties below ignored.
tuning_info	option_fixed		Codec Tuning Info - if specified, some properties below ignored.
level	option_fixed	Auto	Specifies the level of the encoded bitstream.
tier	option_fixed	Main	Set the encoding tier (only level >= 4 can support high tier). This option only takes effect when the level option is specified.
maxrate	int	0	The maximum bit rate in bps is the peak bit rate used for VBR rate control.
size	string		Resolution of video. Format: WIDTHxHEIGHT.
ar	option		Aspect ratio of video.
ar_type	option_fixed		Type of video's aspect ratio.
bufsize	int	0	Specifies the VBV(HRD) buffer size. in bits. Set 0 to use the default VBV buffer size.
initialdelay	int	0	Specifies the VBV(HRD) initial delay in bits. Set 0 to use the default VBV initial delay.
enableAQ	option_fixed	true	Set this to TRUE to enable adaptive quantization.
intraRefreshPeriod	int	0	Specifies the interval between successive intra refresh if intraRefreshCount is set.
intraRefreshCount	int	0	Specifies the length of intra refresh in number of frames for periodic intra refresh. This value should be smaller than intraRefreshPeriod.
mvprecision	option_fixed	Auto	Specifies the desired motion vector prediction precision.
disable_sps_pps	option_fixed	false	Disable writing of Sequence and Picture parameter for every IDR frame.
deblock	option_fixed	true	Set 'true' to enable in loop filtering across slice boundary.
useConstrainedIntraPred	option_fixed		Set 'true' to enable constrained intra prediction.
outputBufferingPeriodSEI	option_fixed	true	Set 'true' to write SEI buffering period syntax in the bitstream.
outputPictureTimingSEI	option_fixed	true	Set 'true' to write SEI picture timing syntax in the bitstream.
outputAUD	option_fixed	true	Set 'true' to write Access Unit Delimiter syntax.
enableLTR	option_fixed		Set 'true' to enable use of long term reference pictures for inter prediction.
maxNumRefFramesInDPB	int		Specifies the maximum number of references frames in the DPB.
ltrNumFrames	int		Specifies the maximum number of long term references can be used for prediction
maxTemporalLayersMinus1	int		Specifies the max temporal layer used for hierarchical coding.
output.10bit	option_fixed	false	Specifies the 10 bit encoding mode
output.444	option_fixed	false	Enable or disable 444 encoding
qpi	int	25	Determines I-frame quality in CQP mode.
qpp	int	28	Determines P-frame quality in CQP mode.
qpb	int	31	Determines B-frame quality in CQP mode.
targetQuality	int	0	Set target quality level (0 to 51, 0 means automatic) for constant quality mode in VBR rate control.
lowDelayKeyFrameScale	int	0	Specifies the Scene Change frame size increase allowed in case of single frame VBV and CBR (from 0 to 255).
enableFillerDataInsertion	int	0	Set to 1 in case the bitrate needs to be strictly adhered to.

NVIDIA NVEnc H.265 (HEVC) Lossless Encoder

Configuration Parameter: l265

Additional attributes

Name	Type	Default	Description
preset	option_fixed	default	Codec Preset - if specified, some properties below ignored.
size	string		Resolution of video. Format: WIDTHxHEIGHT.
ar	option		Aspect ratio of video.
ar_type	option_fixed		Type of video's aspect ratio.
disable_sps_pps	option_fixed	false	Disable writing of Sequence and Picture parameter for every IDR frame.
outputBufferingPeriodSEI	option_fixed	true	Set 'true' to write SEI buffering period syntax in the bitstream.
outputPictureTimingSEI	option_fixed	true	Set 'true' to write SEI picture timing syntax in the bitstream.
outputAUD	option_fixed	true	Set 'true' to write Access Unit Delimiter syntax.
output.10bit	option_fixed	false	Specifies the 10 bit encoding mode.
output.444	option_fixed	false	Enable or disable 444 encoding.

NVIDIA NVEnc AV1 Encoder

Configuration Parameter: nav1

Additional attributes

Name	Type	Default	Description
b	int	5M	The average bit rate in bps is the target bit rate used for rate control.
g	int	15	This is the IDR period.
bf	int	1	This sets the distance of one P picture from the previous P picture. e.g. for IBBPBBP, set the value as 3.
rc_type	option_fixed	Auto	The rate control type.
preset	option_fixed	Auto	Codec Preset - if specified, some properties below ignored.
tuning_info	option_fixed		Codec Tuning Info - if specified, some properties below ignored.
level	option_fixed	Auto	Specifies the level of the encoded bitstream.
tier	option_fixed	Main	Set the encoding tier (only level >= 4 can support high tier). This option only takes effect when the level option is specified.
maxrate	int	0	The maximum bit rate in bps is the peak bit rate used for VBR rate control.
size	string		Resolution of video. Format: WIDTHxHEIGHT.
ar	option		Aspect ratio of video.
ar_type	option_fixed		Type of video's aspect ratio.
bufsize	int	0	Specifies the VBV(HRD) buffer size. in bits. Set 0 to use the default VBV buffer size.
initialdelay	int	0	Specifies the VBV(HRD) initial delay in bits. Set 0 to use the default VBV initial delay.
enableAQ	option_fixed	true	Set this to TRUE to enable adaptive quantization.
outputAnnexBFormat	option_fixed		Set 'true' to use Annex B format for bitstream output.
enableTimingInfo	option_fixed		Set 'true' to write Timing Info into sequence/frame headers.
enableDecoderModelInfo	option_fixed		Set 'true' to write Decoder Model Info into sequence/frame headers.
enableFrameIdNumbers	option_fixed		Set 'true' to write Frame id numbers in bitstream.
disableSeqHdr	option_fixed		Set 'true' to disable Sequence Header signaling in the bitstream.
repeatSeqHdr	option_fixed		Set 'true' to output Sequence Header for every Key frame.
enableBitstreamPadding	option_fixed		Set 'true' to enable bitstream padding.
idrPeriod	int		Specifies the IDR/Key frame interval. If not set, this is made equal to gopLength in NV_ENC_CONFIG.Low latency application client can set IDR interval to NVENC_INFINITE_GOPLENGTH so that IDR frames are not inserted automatically.
intraRefreshPeriod	int	0	Specifies the interval between successive intra refresh if intraRefreshCount is set.
intraRefreshCnt	int	0	Specifies the length of intra refresh in number of frames for periodic intra refresh. This value should be smaller than intraRefreshPeriod.
maxNumRefFramesInDPB	int		Specifies the maximum number of references frames in the DPB.
maxTemporalLayersMinus1	int		Specifies the max temporal layer used for hierarchical coding.
numFwdRefs	int		Specifies max number of forward reference frame used for prediction of a frame. It must be in range 1-4 (Last, Last2, last3 and Golden). It's a suggestive value not necessarily be honored always.
numBwdRefs	int		Specifies max number of L1 list reference frame used for prediction of a frame. It must be in range 1-3 (Backward, Altref2, Altref). It's a suggestive value not necessarily be honored always.
numTileColumns	int		The picture will be uniformly divided into numTileColumns tile columns. If numTileColumns is not a power of 2, it will be rounded down to the next power of 2 value. If numTileColumns == 0, the picture will be coded with the smallest number of vertical tiles as allowed by standard.
numTileRows	int		The picture will be uniformly divided into numTileRows tile rows. If numTileRows is not a power of 2, it will be rounded down to the next power of 2 value. If numTileRows == 0, the picture will be coded with the smallest number of horizontal tiles as allowed by standard.
output.10bit	option_fixed	false	Specifies the 10 bit encoding mode.
qpi	int	25	Determines I-frame quality in CQP mode.
qpp	int	28	Determines P-frame quality in CQP mode.
qpb	int	31	Determines B-frame quality in CQP mode.
targetQuality	int	0	Set target quality level (0 to 51, 0 means automatic) for constant quality mode in VBR rate control.
lowDelayKeyFrameScale	int	0	Specifies the Scene Change frame size increase allowed in case of single frame VBV and CBR (from 0 to 255).

CUDA H.264 Video Encoder

Configuration Parameter: c264

Additional attributes

Name	Type	Default	Description
b	int	6000000	The average bit rate in bps is the target bit rate used for VBR rate control.
maxrate	int	6200000	The maximum bit rate in bps is the peak bit rate used for VBR rate control.
preset	option	Custom	Set the encoding parameters according to the presets required for supported encoding targets.
size	string		Resolution of video. Format: WIDTHxHEIGHT.
g	int	15	This is the IDR period for H264.
bf	int	1	This sets the distance of one P picture from the previous P picture. e.g. for IBBPBBP, set the value as 3.
dynamic_gop	option_fixed	false	The GOP structure is determined dynamically by the encoder.
profile	option_fixed	Main	Set the profile and level information.
nal_type	int	0	Configures the NAL unit framing type.
rc_type	option_fixed	vbr	The rate control type.
qp_level_i	int	28	The QP level for intra pictures.
qp_level_p	int	28	The QP level for inter P pictures.
qp_level_b	int	28	The QP level for inter B pictures.
deblock	option_fixed	true	Enable or disable de-blocking mode.
disable_cabac	option_fixed	false	Enable or disable CABAC.
disable_sps_pps	option_fixed	false	Enable or disable including sequence parameter set/picture parameter set ( SPS/PPS ) information in bitstream.
deinterlace	option_fixed		Enable the deinterlace algorithm.

Cisco libopenh264 H.264/MPEG-4 AVC Encoder

Configuration Parameter: libopenh264

Additional attributes

Name	Type	Default	Description
b	int	5000000	Set the bitrate (as a number of bits per second).
maxrate	int	5000000	Set the max bitrate (as a number of bits per second).
profile	option_fixed	Main	Set profile restrictions. If set to the value of ‘main’ enable CABAC.
size	string		Resolution of video. Format: WIDTHxHEIGHT.
g	int	15	Set the GOP size.
slices	int	0	Set the number of slices, used in parallelized encoding. Default value is 0. This is only used when slice_mode is set to ‘fixed’.
slice_mode	option_fixed	auto	Set slice mode.
loopfilter	int	1	Enable loop filter, if set to 1 (automatically enabled). To disable set a value of 0.
max_nal_size	int	0	Set maximum NAL size in bytes.
allow_skip_frames	int	0	Allow skipping frames to hit the target bitrate if set to 1.
flags	string	+global_header	Set global header in the bitstream
coder	option_fixed	cavlc	Set entropy encoder. Possible values: cavlc, cabac

libx264 H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10

Configuration Parameter: libx264

Additional attributes

Name	Type	Default	Description
preset	string	faster	Change options to trade off compression efficiency against encoding speed. Values available: ultrafast, superfast, veryfast, faster, fast, medium, slow, slower, veryslow, placebo.
tune	string	zerolatency	Tune options to further optimize them for your input content. Values available: film, animation, grain, stillimage, psnr, ssim, fastdecode, zerolatency.
profile	string		Limit the profile of the output stream. Values available: baseline, main, high, high10, high422, high444.
fastfirstpass	int	1	Use fast settings when encoding first pass
level	string		Sets the level flag in the output bitstream (as defined by Annex A) Permissible levels are: 1 1b 1.1 1.2 1.3 2 2.1 2.2 3 3.1 3.2 4 4.1 4.2 5 5.1
wpredp	string		Weighted prediction for P-frames
x264-params	string		Override the x264 configuration using a :-separated list of key=value options. The argument for both options is a list of key=value couples separated by ":". With x264opts the value can be omitted, and the value 1 is assumed in that case
crf	double	-1.000000	Select the quality for constant quality mode
crf_max	double	-1.000000	In CRF mode, prevents VBV from lowering quality beyond this point.
qp	int	-1	Constant quantization parameter rate control method
aq-mode	option_fixed		AQ method
aq_mode			Set adaptive quantization mode autovariance - Auto-variance AQ (experimental) size - Resolution of video. Format: WIDTHxHEIGHT. ar - Aspect ratio of video. ar_type - Type of video's aspect ratio.
v422	option_fixed	false	Indicates whether captioning used 4:2:2 chroma subsampling (4:2:0 overwise).
interlace	int	-1	Interlacing: 1 - interlaced, 0 - progressive, -1 - auto.
aq-strength	double	-1.000000	AQ strength. Reduces blocking and blurring in flat and textured areas.
psy	int	-1	Use psychovisual optimizations.
psy-rd	string		Strength of psychovisual optimization, in : format.
rc-lookahead	int	-1	Number of frames to look ahead for frametype and ratecontrol
weightb	int	-1	Weighted prediction for B-frames.
weightp	option_fixed		Weighted prediction analysis method.
ssim	int	-1	Calculate and print SSIM stats.
intra-refresh	int	-1	Use Periodic Intra Refresh instead of IDR frames.
b-bias	int	-2147483648	Influences how often B-frames are used
b-pyramid	option_fixed		Keep some B-frames as references.
b_pyramid			normal - Non-strict (not Blu-ray compatible)
mixed-refs	int	-1	One reference per partition, as opposed to one reference per macroblock
8x8dct	int	-1	High profile 8x8 transform.
fast-pskip	int	-1
aud	int	-1	Use access unit delimiters.
mbtree	int	-1	Use macroblock tree ratecontrol.
deblock	string		Loop filter parameters, in form.
cplxblur	double	-1.000000	Reduce fluctuations in QP (before curve compression)
partitions	string		A comma-separated list of partitions to consider. Possible values: p8x8, p4x4, b8x8, i8x8, i4x4, none, all
direct-pred	option_fixed		Direct MV prediction mode
slice-max-size	int	-1	Limit the size of each slice in bytes
stats	string		Filename for 2 pass stats
nal-hrd	option_fixed		Signal HRD information (requires vbv-bufsize; cbr not allowed in .mp4)

x265 H.265/HEVC

Configuration Parameter: libx265

Additional attributes

Name	Type	Default	Description
preset	option	superfast	Set the x265 preset.
tune	option		Set the x265 tune parameter. Possible values: psnr (disables adaptive quant, psy-rd, and cutree), ssim (enables adaptive quant auto-mode, disables psy-rd), grain (improves retention of film grain), fastdecode (no loop filters, no weighted pred, no intra in B), zerolatency (no lookahead, no B frames, no cutree).
forced-idr	int	0	Normally, when forcing a I-frame type, the encoder can select any type of I-frame. This option forces it to choose an IDR-frame.
x265-params	string		Set x265 options using a list of key=value couples separated by ":".

FLV / Sorenson Spark / Sorenson H.263 (Flash Video)

Configuration Parameter: flv

Additional attributes

Name	Type	Default	Description
mpv_flags	flags		Flags common for all mpegvideo-based encoders. skip_rd - RD optimal MB level residual skipping strict_gop - Strictly enforce GOP size qp_rd - Use rate distortion optimization for qp selection cbp_rd - use rate distortion optimization for CBP

HuffYUV

Configuration Parameter: huffyuv

VC-1

Configuration Parameter: vc1

MJPEG (Motion JPEG)

Configuration Parameter: mjpeg

Name	Type	Default	Description
color_range	option	jpeg	MPEG vs JPEG YUV range. Possible values: unspecified, mpeg, jpeg

MPEG-1 Video

Configuration Parameter: mpeg1video

Additional attributes

Name	Type	Default	Description
mpv_flags	flags		Flags common for all mpegvideo-based encoders. skip_rd - RD optimal MB level residual skipping strict_gop - Strictly enforce GOP size qp_rd - Use rate distortion optimization for qp selection cbp_rd - use rate distortion optimization for CBP

Vidvox Hap

Configuration Parameter: hap

Additional attributes

Name	Type	Default	Description
format	option		Possible values: hap, hap_alpha, hap_q.
chunks	int	1	Chunk count.
compressor	option	snappy	Second-stage compressor.

FFV1

Configuration Parameter: ffv1

Additional attributes

Name	Type	Default	Description
coder	option_fixed	0	0=Golomb-Rice, 1=Range Coder, 2=Range Coder (with custom state transition table)
context	option_fixed	0	0=small, 1=large
g	int	1	GOP size. For archival use, GOP-size should be "1".
level	option_fixed	1	Version. Select which FFV1 version to use.
threads	int	1	Threads. The number of threads to use while processing. Adjust this to match how many of your available CPU cores you want to use.
slices	option_fixed	4	Slices. Each frame is split into this number of slices. This affects multithreading performance, as well as filesize: Increasing the number of slices might speed up performance, but also increases the filesize.
slicecrc	option_fixed	0	Error correction/detection. 0=off, 1=on. Enabling this option adds CRC information to each slice. This makes it possible for a decoder to detect errors in the bitstream, rather than blindly decoding a broken slice.

MPEG-2 Video

Configuration Parameter: mpeg2video

Additional attributes

Name	Type	Default	Description
mpv_flags	flags		Flags common for all mpegvideo-based encoders. skip_rd - RD optimal MB level residual skipping strict_gop - Strictly enforce GOP size qp_rd - Use rate distortion optimization for qp selection cbp_rd - use rate distortion optimization for CBP
gop_timecode	string		GOP timecode value
v422	option_fixed	false	Indicates whether captioning used 4:2:2 chroma subsampling (4:2:0 overwise).
interlace	int	-1	Interlacing: 1 - interlaced, 0 - progressive, -1 - auto.

MPEG-4 part 2 Video

Configuration Parameter: mpeg4

Additional attributes

Name	Type	Default	Description
data_partitioning	int	0	Use data partitioning.
mpv_flags	flags		Flags common for all mpegvideo-based encoders. skip_rd - RD optimal MB level residual skipping strict_gop - Strictly enforce GOP size qp_rd - Use rate distortion optimization for qp selection cbp_rd - use rate distortion optimization for CBP
interlace	int	-1	Interlacing: 1 - interlaced, 0 - progressive, -1 - auto.

Apple ProRes

Configuration Parameter: prores

Apple ProRes (iCodec Pro)

Configuration Parameter: prores_ks

Name	Type	Default	Description
mbs_per_slice	int	8	Macroblocks per slice.
profile	option	auto	Profile name. Possible values: auto, proxy, lt, standard, hq, 4444, 4444xq.
vendor	string	Lavc	Vendor ID.
bits_per_mb	int	0	Desired bits per macroblock.
quant_mat	option	auto	Quantiser matrix.
alpha_bits	int	16	Bits for alpha plane.

Windows Media Video 8

Configuration Parameter: wmv2

OpenJPEG JPEG 2000

Configuration Parameter: libopenjpeg

Additional attributes

Name	Type	Default	Description
format	option_fixed	jp2	Codec Format. Possible values: j2k, jp2.
profile	option_fixed	jpeg2000	Profile name. Possible values: jpeg2000, cinema2k, cinema4k.
cinema_mode	option_fixed	off	Digital Cinema mode. Possible values: off, 2k_24, 2k_48, 4k_24
numresolution	int	6	Number of resolutions
numlayers	int	1	Number of layers

Google VP8

Configuration Parameter: libvpx

Additional attributes

Name	Type	Default	Description
cpu-used	int	3	Quality/Speed ratio modifier.
quality	int	1000000	Encoding quality.
max-intra-rate	int	-1	Maximum I-frame bitrate (pct) 0=unlimited.
er		default	partitions - The frame partitions are independently decodable by the bool decoder, meaning that partitions can be decoded even though earlier partitions have been lost. Note that intra predicition is still done over the partition boundary.
speed	int	3	Encoding speed.
crf	int	-1	Select the quality for constant quality mode.
frame-parallel		1	Enable frame parallel decodability features.
lag-in-frames	int	4	Number of frames to look ahead for alternate reference frame selection.
auto-alt-ref	int	-1	Enable use of alternate reference frames (2-pass only).
qmin	int	4	Min video quantizer scale (VBR).
qmax	int	48	Max video quantizer scale (VBR).

AMD AMF H.264 Encoder

Configuration Parameter: h264_amf

Additional attributes

Name	Type	Default	Description
b	int	5M	The average bit rate in bps is the target bit rate used for VBR rate control.
g	int	15	Group of picture (GOP) size.
maxrate	int	0	Set max bitrate tolerance (in bits/s). Requires bufsize to be set.
minrate	int	0	Set min bitrate tolerance (in bits/s). Most useful in setting up a CBR encode. It is of little use elsewise.
bufsize	int	0	Set ratecontrol buffer size (in bits). Depends on the profile level of the video being encoded. Set only if you're encoding for a hardware device.
bf	int	0	This sets the distance of one P picture from the previous P picture. e.g. for IBBPBBP, set the value as 3.
usage	option_fixed	transcoding	Encoder Usage.
profile	option_fixed	main	Profile.
level	option_fixed	auto	Profile Level.
quality	option_fixed	speed	Quality Preference.
rc	option_fixed	cqp	Rate Control Method.
enforce_hrd	bool	false	Enforce HRD.
filler_data	bool	false	Filler Data Enable.
vbaq	bool	false	Enable VBAQ.
frame_skipping	bool	false	Rate Control Based Frame Skip.
qp_i	int	-1	Quantization Parameter for I-Frame.
qp_p	int	-1	Quantization Parameter for P-Frame.
qp_b	int	-1	Quantization Parameter for B-Frame.
preanalysis	bool	false	Pre-Analysis Mode.
max_au_size	int	0	Maximum Access Unit Size for rate control (in bits).
header_spacing	int	-1	Header Insertion Spacing.
bf_delta_qp	int	4	B-Picture Delta QP.
bf_ref	bool	true	Enable Reference to B-Frames.
bf_ref_delta_qp	int	4	Reference B-Picture Delta QP.
intra_refresh_mb	int	0	Intra Refresh MBs Number Per Slot in Macroblocks.
coder	option_fixed	auto	Coding Type.
me_half_pel	bool	true	Enable ME Half Pixel.
me_quarter_pel	bool	true	Enable ME Quarter Pixel.
aud	bool	false	Inserts AU Delimiter NAL unit.
deblock	bool	false	Enable or disable de-blocking mode.

AMD AMF H.265 (HEVC) Encoder

Configuration Parameter: hevc_amf

Additional attributes

Name	Type	Default	Description
b	int	5M	The average bit rate in bps is the target bit rate used for VBR rate control
g	int	15	Group of picture (GOP) size
maxrate	int	0	Set max bitrate tolerance (in bits/s). Requires bufsize to be set
minrate	int	0	Set min bitrate tolerance (in bits/s). Most useful in setting up a CBR encode. It is of little use elsewise
bufsize	int	0	Set ratecontrol buffer size (in bits). Depends on the profile level of the video being encoded. Set only if you're encoding for a hardware device.
bf	int	1	This sets the distance of one P picture from the previous P picture. e.g. for IBBPBBP, set the value as 3
usage	option_fixed	transcoding	Encoder Usage
profile	option_fixed	main	Profile
profile_tier	option_fixed	main	Profile tier
level	option_fixed	auto	Profile Level
quality	option_fixed	balanced	Quality Preference
rc	option_fixed	cqp	Rate Control Method
header_insertion_mode	option_fixed	none	Header insertion mode
gops_per_idr	int	60	GOPs per IDR 0-no IDR will be inserted
preanalysis	bool	false	Pre-Analysis Mode
vbaq	bool	false	Enable VBAQ
enforce_hrd	bool	false	Enforce HRD
filler_data	bool	false	Filler Data Enable
max_au_size	int	0	Maximum Access Unit Size for rate control (in bits)
min_qp_i	int	-1	Min quantization parameter for I-frame
max_qp_i	int	-1	Max quantization parameter for I-frame
min_qp_p	int	-1	Min quantization parameter for P-frame
max_qp_p	int	-1	Max quantization parameter for P-frame
qp_p	int	-1	Quantization parameter for P-frame
qp_i	int	-1	Quantization parameter for I-frame
skip_frame	bool	false	Rate Control Based Frame Skip
me_half_pel	bool	true	Enable ME Half Pixel
me_quarter_pel	bool	true	Enable ME Quarter Pixel
aud	bool	false	Inserts AU Delimiter NAL unit

libvpx VP9

Configuration Parameter: libvpx-vp9

Additional attributes

Name	Type	Default	Description
g	int	75	Keyframe interval, also known as GOP length. This determines the maximum distance between I-frames. Very high GOP lengths will result in slightly more efficient compression, but will make seeking in the video somewhat more difficult.
auto-alt-ref	int	-1	Enable use of alternate reference frames (2-pass only).
lag-in-frames	int	25	Number of frames to look ahead for alternate reference frame selection.
arnr-maxframes	int	0	altref noise reduction max frame count.
arnr-strength	int	3	altref noise reduction filter strength.
arnr-type	option	centered	altref noise reduction filter type.
arnr_type	int	3	altref noise reduction filter type.
tune	option		Tune the encoding to a specific scenario. Possible values: psnr, ssim.
deadline	option	good	Time to spend encoding, in microseconds.
quality	int	realtime	Possible values: best, good, realtime.
error-resilient	flags		Error resilience configuration. Select from er.
max-intra-rate	int	-1	Maximum I-frame bitrate (pct) 0=unlimited
er			default - Improve resiliency against losses of whole frames partitions - The frame partitions are independently decodable by the bool decoder, meaning that partitions can be decoded even though earlier partitions have been lost. Note that intra predicition is still done over the partition boundary.
crf	int	-1	Select the quality for constant quality mode
static-thresh	int	0	A change threshold on blocks below which they will be skipped by the encoder.
drop-threshold	int	0	Frame drop threshold.
noise-sensitivity	int	0	Noise sensitivity.
undershoot-pct	int	-1	Datarate undershoot (min) target (%).
overshoot-pct	int	-1	Datarate overshoot (max) target (%).
cpu-used	int	1	Quality/Speed ratio modifier.
lossless	int	-1	Lossless mode.
tile-columns	int	-1	Number of tile columns to use, log2.
tile-rows	int	-1	Number of tile rows to use, log2.
frame-parallel		1	Enable frame parallel decodability features.
aq-mode	option		Adaptive quantization mode.
aq_mode			variance - Variance based Aq complexity - Complexity based Aq cyclic - Cyclic Refresh Aq equator360 - 360 video Aq
level	double	-1.000000	Specify level.
row-mt			Row based multi-threading.
tune-content	option		Tune content type.
tune_content			default - Regular video content screen - Screen capture content film - Film content; improves grain retention
corpus-complexity	int	-1	Corpus vbr complexity midpoint.
speed	int	5	Encoding speed.
vp8flags	flags		Select from flags.
flags			error_resilient - Enable error resilience altref - enable use of alternate reference frames (VP8/2-pass only).
arnr_max_frames	int	0	altref noise reduction max frame count.
arnr_strength	int	3	altref noise reduction filter strength.
rc_lookahead	int	25	Number of frames to look ahead for alternate reference frame selection.
qmin	int	4	Min video quantizer scale (VBR).
qmax	int	48	Max video quantizer scale (VBR).

DNxHD (Digital Nonlinear Extensible High Definition)

Configuration Parameter: dnxhd

Additional attributes

Name	Type	Default	Description
b	int	120M	Set bitrate (in bits/s).
nitris_compat	bool	false	Encode with Avid Nitris compatibility.

QuickTime Animation (RLE) video

Configuration Parameter: qtrle

DPX (Digital Picture Exchange) image

Configuration Parameter: dpx