See also, the list of all parameters
[TOC]
This document describes how to use the Scalable Video Technology for AV1 Encoder (SVT-AV1). In particular, this user guide describes how to run the sample application with the respective dynamically linked library.
This section describes how to run the sample encoder application that uses the SVT-AV1 Encoder library. It describes the input video format, the command line input parameters and the resulting outputs.
The SVT-AV1 Encoder supports the following input formats:
8-bit yuv420p
10-bit yuv420p10le
In order to reduce the size of the input original YUV file, the SVT-AV1 Encoder uses a compressed 10-bit format allowing the software to achieve a higher speed and channel density levels. The conversion between the 10-bit yuv420p10le and the compressed 10-bit format is a lossless operation and is performed using the following steps.
This step consists of separating the 10 bit video samples into 8 bit and 2 bit planes so that each 10-bit picture will be represented as two separate pictures as shown in the figure below. As a result of the operation, the 2 least significant bits of the 10 bits will be written into a full byte.
10-bit yuv420p10le unpacked
The unpacking steps separates the 10bits into a group of 8 bits and a group of 2 bits, where the 2 bits are stored in a byte. In this step, every group of consecutive 4 bytes, each containing 2bits from the unpacking step, are compressed into one byte. As a result, each 10bit picture will be represented as two separate pictures as shown in the figure below.
10-bit yuv420p10le compressed
Now for a faster read of the samples, every 64x64 block of the 2 bit picture should be written into a one dimensional array. Therefore, the top left 64x64 sample block which is now written into a 16 bytes x 64 bytes after the compression of the 2bit samples, will be written into a 1024 bytes x 1 byte array as shown in the picture below.
64x64 block after 2 bit compression
64x64 block after unrolling
This section describes how to run the sample encoder application
SvtAv1EncApp.exe (on Windows*) or SvtAv1EncApp (on Linux*) from the
command line, including descriptions of the most commonly used input parameters
and outputs.
The sample application typically takes the following command line parameters:
-c filename [Optional]
A text file that contains encoder parameters such as input file name, quantization parameter etc. Refer to the comments in the Config/Sample.cfg for specific details. The list of encoder parameters are also listed below. Note that command line parameters take precedence over the parameters included in the configuration file when there is a conflict.
-i filename [Required]
A YUV file (e.g. 8 bit 4:2:0 planar) containing the video sequence that will be
encoded. The dimensions of each image are specified by -w and -h as
indicated below.
-b filename [Optional]
The resulting encoded bit stream file in binary format. If none specified, no output bit stream will be produced by the encoder.
-w integer [Required]
The width of each input image in units of picture luma pixels, e.g. 1920
-h integer [Required]]
The height of each input image in units of picture luma pixels, e.g. 1080
-n integer [Optional]
The number of frames of the sequence to encode. e.g. 100. If the input frame count is larger than the number of frames in the input video, the encoder will loopback to the first frame when it is done.
--keyint integer [Optional]
The keyint defines the display order location at which the encoder would insert
a keyframe. It is recommended to use a value that is (a multiple of the mini
GOP size (default 16)) + 1 so that the keyframe does not break a mini GOP
formation. When using forward frame, it is recommended that the keyint value is
placed at a multiple of mini-gop size. The mini-gop size is measured by 1 << hierarchical-levels.
SvtAv1EncApp only: optionally accepts a s suffix to indicate to use keyint * frame-rate as the keyint value. e.g. --keyint 5s for 5 seconds
--rc integer [Optional]
The rc token sets the bitrate control encoding mode [0: Constant QP OR Constant Rate Factor, 1: Variable Bitrate, 2: Constant Bitrate].
With --rc set to 0, CQP (fixed qp offsets regardless of the content) mode is
enabled using --aq-mode 0, else CRF mode (default) will be used. If --crf
is set, then aq-mode will be forced to 2, however, if -q/--qp is set, then
the encoder will use whatever is set for aq-mode.
If a qp/crf value is not specified, a default value is assigned (35).
Here are some sample encode command lines
SvtAv1EncApp -i input.yuv -w 1920 -h 1080 --fps 24 --crf 30 --preset 12 -b output.ivf
Single command line :
SvtAv1EncApp -i input.yuv -w 1920 -h 1080 --fps 24 --crf 30 --preset 0 --passes 2 -b output.ivf
or
Multiple command lines :
SvtAv1EncApp -i input.yuv -w 1920 -h 1080 --fps 24 --crf 30 --preset 0 --pass 1 --stats stat_file.stat
SvtAv1EncApp -i input.yuv -w 1920 -h 1080 --fps 24 --crf 30 --preset 0 --pass 2 --stats stat_file.stat -b output.ivf
SvtAv1EncApp -i input.yuv -w 1920 -h 1080 --fps 24 --rc 1 --tbr 1000 --preset 5 -b output.ivf
Single command line :
SvtAv1EncApp -i input.yuv -w 1920 -h 1080 --fps 24 --rc 1 --tbr 1000 --preset 0 --passes 2 --stats stat_file.stat -b output.ivf
or
Multiple command lines :
SvtAv1EncApp -i input.yuv -w 1920 -h 1080 --fps 24 --rc 1 --tbr 1000 --preset 0 --pass 1 --stats stat_file.stat
SvtAv1EncApp -i input.yuv -w 1920 -h 1080 --fps 24 --rc 1 --tbr 1000 --preset 0 --pass 2 --stats stat_file.stat
SvtAv1EncApp -i input.yuv -w 1920 -h 1080 --fps 24 --rc 1 --tbr 1000 --preset 0 --pass 3 --stats stat_file.stat -b output.ivf
SvtAv1EncApp -i input.yuv -w 1920 -h 1080 --fps 24 --crf 30 --preset 12 --color-range full -b output.ivf
SvtAv1EncApp -i input.yuv -w 1920 -h 1080 --fps 24 --crf 30 --preset 12 --color-primaries bt709 --transfer-characteristics bt709 --matrix-coefficients bt709 -b output.ivf