Examples of Using HW265Enc in FFmpeg

The following uses the conversion from a YUV file to an MP4 file as an example to describe how to use the encoding commands of HW265Enc in FFmpeg.

When you enter command line parameters, the output file name must be written at the end, and other FFmpeg built-in parameters must be written after the ffmpeg command. The libhw265 encoder parameters are written after libhw265. Parameter types and descriptions are shown in Table 1.

Command example:

ffmpeg -s 1920x1080 -i input.yuv -bf 0 -c:v libhw265 -wpp_threads 4 output.mp4

Information similar to the following is displayed:

Input #0, rawvideo, from 'input.yuv':
  Duration: 00:01:00.00, start: 0.000000, bitrate: 622080 kb/s
    Stream #0:0: Video: rawvideo (I420 / 0x30323449), yuv420p, 1920x1080, 622080 kb/s, 25 tbr, 25 tbn, 25 tbc
File 'output.mp4' already exists. Overwrite ? [y/N] y
Stream mapping:
  Stream #0:0 -> #0:0 (rawvideo (native) -> hevc (libhw265))
Press [q] to stop, [?] for help
Output #0, mp4, to 'output.mp4':
  Metadata:
    encoder         : Lavf58.29.100
    Stream #0:0: Video: hevc (libhw265) (hev1 / 0x31766568), yuv420p, 1920x1080, q=2-31, 200 kb/s, 25 fps, 12800 tbn, 25 tbc
    Metadata:
      encoder         : Lavc58.54.100 libhw265
frame= 1500 fps= 13 q=-0.0 Lsize=   34439kB time=00:00:58.96 bitrate=4785.1kbits/s speed=0.504x    
video:34432kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.020906%

**Table 1** FFmpeg command line parameters
FFmpeg Command Line Parameter	Parameter Type	Description
-i	FFmpeg built-in parameter	Name of the input file. It corresponds to the command line parameter -i of CloudHw265App.
-s	FFmpeg built-in parameter	Width and height of the input image. It corresponds to the command line parameters -w and -h of CloudHw265App.
-vframes	FFmpeg built-in parameter	Number of frames to be encoded. It corresponds to the command line parameter --frames of CloudHw265App.
-fps_num	libhw265 encoder parameter	Frame rate of the output video. The value range is (0, 120]. If the value does not fall within the range, the default value 25 is used. It corresponds to the command line parameter --fps_num of CloudHw265App. In this case, the default value of fps_den is 1.
-channel	libhw265 encoder parameter	ID of the current encoder. The encoder ID is used to identify different encoders. The default value is 0.
-log_level	libhw265 encoder parameter	Encoder log output level. The default value is 1. 0: Disables the log function. 1: Enables the error output. Only error information is reported. 2: Enables the warning output. Only warning information and information below the warning level are reported. 3: Enables the info output. Only important information and information below the info level are reported. 4: Enables the debug output. Only debugging information and information below the debug level are reported.
-frame_threads	libhw265 encoder parameter	Number of threads for frame-level encoding. A larger value indicates a higher encoding speed. The value range is [1, 38] and the default value is 12. If this parameter is set to a value outside the range, the default value is used or an error is reported. It corresponds to the command line parameter --FrmThreadNum of CloudHw265App.
-wpp_threads	libhw265 encoder parameter	Number of threads for WPP row-level encoding. A larger value indicates a higher encoding speed. The value range is [1, 20] and the default value is 8. It corresponds to the command line parameter --WppThreadNum of CloudHw265App.
-analysis_threads	libhw265 encoder parameter	Number of threads for pre-analysis. Pre-analysis scans the upcoming frames in advance, which improves the encoding image quality but increases the encoding latency. The value range is [1, 48] and the default value is 5. It corresponds to the command line parameter --LookAheadThreads of CloudHw265App.
-adap_I	libhw265 encoder parameter	Specifies whether to enable scene-adaptive I-frame insertion. If this function is enabled, the encoding quality is improved but the encoding speed decreases. The value range is [0, 1] and the default value is 1. If this parameter is set to a value outside the range, the default value is used. It corresponds to the command line parameter --adapt_i of CloudHw265App.
-profile	libhw265 encoder parameter	Encoding complexity of the HW265 encoder. Only the main profile is supported. The default value is 0.
-qualityset	libhw265 encoder parameter	Sets the encoding quality level. Available level options are 2, 3, 5, and 6. The encoding speed increases with each level, while the corresponding encoding quality decreases. The default value is 3. It corresponds to the command line parameter --preset of CloudHw265App.
-keyint	libhw265 encoder parameter	I-frame interval. Typically, a larger value indicates lower image quality and faster encoding. The value is greater than or equal to 1. The default value is 150. It corresponds to the command line parameter --keyInt of CloudHw265App.
-bframe_nums	libhw265 encoder parameter	Maximum consecutive B-frames. Typically, a larger value indicates higher image quality and slower encoding at the same bit rate. The value range is [0, 7] and the default value is 7. It corresponds to the command line parameter --bframes of CloudHw265App.
-delay	libhw265 encoder parameter	Number of frames buffered for time-domain analysis. Typically, a larger value indicates higher image quality and slower encoding at the same bit rate. The value range is [bframes, 150] and the default value is 25. It corresponds to the command line parameter --delay of CloudHw265App.
-rc	libhw265 encoder parameter	Bit rate control policy. The value can be 0, 1, and 2, indicating constant quantization parameter (CQP), average bit rate (ABR), and constant quality factor (CRF), respectively. If the value does not fall within the range, the default value 0 is used. It corresponds to the command line parameter --rc of CloudHw265App.
-qp	libhw265 encoder parameter	Quantization parameter (QP). Typically, a smaller value indicates a smaller quantization step size and higher precision. The output data volume may be larger for the same visual quality. The value range is [1, 51] and the default value is 18. This parameter is valid only in the CQP mode.
-abr_bitrate	libhw265 encoder parameter	Average bit rate. Typically, a larger value indicates higher image quality and slower encoding. The value range is [40, 300000], in kbit/s. If the value is out of the range, the default value 2000 is used. It corresponds to the command line parameter --br of CloudHw265App. This parameter is valid only in the ABR mode.
-crf	libhw265 encoder parameter	CRF level. Typically, a smaller value indicates a higher bit rate and image quality but slower encoding. The value range is [0, 51]. If the value is out of the range, the default value 23 is used. It corresponds to the command line parameter --crf of CloudHw265App. This parameter is valid only in the CRF mode.
-cfps	libhw265 encoder parameter	Specifies whether to set a constant frame rate. 0: no; 1: yes. The default value is 1. If this parameter is set to a value outside the range, the default value is used. It corresponds to the command line parameter -vfrinput of CloudHw265App, with inverse functionality.
-enablefixedIdrPeriod	libhw265 encoder parameter	Specifies whether a fixed interval always contains an I-frame. This parameter takes effect only when -adap_I is enabled. 0: no; 1: yes. The default value is 0. This parameter does not have a corresponding CloudHw265App command line parameter.
-bitratePar	libhw265 encoder parameter	Peak-to-average bit rate ratio. The value range is [1, 20] and the default value is 4. If this parameter is set to a value outside the range, the default value is used. It corresponds to the command line parameter -BitRatePAR of CloudHw265App.
-bitrateParCtrlStrength	libhw265 encoder parameter	Peak control strength. The value range is [0, 3] and the default value is 0. If this parameter is set to a value outside the range, the default value is used. It corresponds to the command line parameter -ParCovStrength of CloudHw265App.
-enableResetBitrate	libhw265 encoder parameter	Specifies whether to enable bit rate resetting. 0: no; 1: yes. The default value is 0. It corresponds to the command line parameter -dynamicBitrateMode of CloudHw265App. If the value is 0, the bit rate is not reset.
-bframe_ref	libhw265 encoder parameter	Specifies whether to use the B-frame as the reference frame. 0: no; 1: yes. The default value is 1. If this parameter is set to a value outside the range, the default value is used. It corresponds to the command line parameter -bframeRef of CloudHw265App.
-MbTree	libhw265 encoder parameter	Specifies whether to enable the MBTree bit rate control algorithm to intelligently allocate the bit rate based on the macroblock importance. 0: no; 1: yes. The default value is 1. If this parameter is set to a value outside the range, the default value is used. This parameter does not have a corresponding CloudHw265App command line parameter.
-delayTime	libhw265 encoder parameter	Time-domain analysis wait time. The value range is [0, 4000] and the default value is 0. It corresponds to the command line parameter -TotalDelayTime of CloudHw265App.
-enableDelayTimeControl	libhw265 encoder parameter	Specifies whether to enable time-domain analysis wait time control. 0: no; 1: yes. The default value is 0. If this parameter is set to a value outside the range, the default value is used. This parameter does not have a corresponding CloudHw265App command line parameter.
-adap_B	libhw265 encoder parameter	Sets the adaptive B-frame algorithm. Available options are 0 (disabled), 1 (fastest adaptation), 2 (fast adaptation), and 3 (TRELLTS-based adaptation). The default value is 1. If this parameter is set to a value outside the range, the default value is used. This parameter does not have a corresponding CloudHw265App command line parameter.

For details about how to use FFmpeg, see the official FFmpeg website.

Parent topic: FFmpeg+HW265Enc Compilation and Usage Guide