ffmpeg

README

FFplay output

FFplay 7.11 A-V: 0.003 fd= 1 aq= 21KB vq= 321KB sq= 0B f=0/0:

• 7.11 - master clock, is the time from start of the stream/video
• A-V - av_diff, difference between audio and video timestamps
• fd - frames dropped
• aq - audio queue (0 - no delay)
• vq - video queue (0 - no delay)
• sq - subtitle queue
• f - timestamp error correction rate (Not 100% sure)

M-V, M-A means video stream only, audio stream only respectively.

Devices Windows

>ffmpeg -hide_banner -f dshow -list_options true -i video="VMware Virtual USB Video Device"
[dshow @ 0000025695e52900] DirectShow video device options (from video devices)
[dshow @ 0000025695e52900]  Pin "Record" (alternative pin name "0")
[dshow @ 0000025695e52900]   pixel_format=yuyv422  min s=1280x720 fps=1 max s=1280x720 fps=10
[dshow @ 0000025695e52900]   pixel_format=yuyv422  min s=1280x720 fps=1 max s=1280x720 fps=10 (tv, bt470bg/bt709/unknown, topleft)
[dshow @ 0000025695e52900]   pixel_format=nv12  min s=1280x720 fps=1 max s=1280x720 fps=23
[dshow @ 0000025695e52900]   pixel_format=nv12  min s=1280x720 fps=1 max s=1280x720 fps=23 (tv, bt470bg/bt709/unknown, topleft)

Devices Mac

% ./ffmpeg -hide_banner -f avfoundation -list_devices true -i ""
[AVFoundation indev @ 0x7f8b1f504d80] AVFoundation video devices:
[AVFoundation indev @ 0x7f8b1f504d80] [0] FaceTime HD Camera
[AVFoundation indev @ 0x7f8b1f504d80] [1] Capture screen 0
[AVFoundation indev @ 0x7f8b1f504d80] AVFoundation audio devices:
[AVFoundation indev @ 0x7f8b1f504d80] [0] Soundflower (2ch)
[AVFoundation indev @ 0x7f8b1f504d80] [1] Built-in Microphone
[AVFoundation indev @ 0x7f8b1f504d80] [2] Soundflower (64ch)

Devices Linux

# ffmpeg -hide_banner -f v4l2 -list_formats all -i /dev/video0
[video4linux2,v4l2 @ 0x7f7de7c58bc0] Raw       :     yuyv422 :           YUYV 4:2:2 : 640x480 160x120 176x144 320x176 320x240 352x288 432x240 544x288 640x360 752x416 800x448 800x600 864x480 960x544 960x720 1024x576 1184x656 1280x720 1280x960
[video4linux2,v4l2 @ 0x7f7de7c58bc0] Compressed:       mjpeg :          Motion-JPEG : 640x480 160x120 176x144 320x176 320x240 352x288 432x240 544x288 640x360 752x416 800x448 800x600 864x480 960x544 960x720 1024x576 1184x656 1280x720 1280x960

Useful links

• https://superuser.com/questions/564402/explanation-of-x264-tune
• https://stackoverflow.com/questions/33624016/why-sliced-thread-affect-so-much-on-realtime-encoding-using-ffmpeg-x264
• https://codec.fandom.com/ru/wiki/X264_-_описание_ключей_кодирования
• https://html5test.com/
• https://trac.ffmpeg.org/wiki/Capture/Webcam
• https://trac.ffmpeg.org/wiki/DirectShow
• https://stackoverflow.com/questions/53207692/libav-mjpeg-encoding-and-huffman-table
• https://github.com/tuupola/esp_video/blob/master/README.md
• https://github.com/leandromoreira/ffmpeg-libav-tutorial
• https://www.reddit.com/user/VeritablePornocopium/comments/okw130/ffmpeg_with_libfdk_aac_for_windows_x64/
• https://slhck.info/video/2017/02/24/vbr-settings.html
• HomeKit audio samples problem

Documentation

Index

• func Init()
• func JPEGWithQuery(b []byte, query url.Values) ([]byte, error)
• func JPEGWithScale(b []byte, width, height int) ([]byte, error)

Functions

func Init

func Init()

func JPEGWithQuery

func JPEGWithQuery(b []byte, query url.Values) ([]byte, error)

func JPEGWithScale

func JPEGWithScale(b []byte, width, height int) ([]byte, error)