Development -ffmpeg audio and video instructions (2)

YUV data extraction

ffmpeg -i input.mp4 -an -c:v rawvideo -pix_fmt yuv420p out.yuv

-i input file
-an Audio NO
-c: v equal -vcodec
-pix_fmt pixel format

PCM data extraction

ffmpeg -i out.flv -vn -ar 44100 -ac 2 -f s16le out.pcm

-i input file
-vn Video NO
-Ar Audio Sample Rate Read
-ac audio count the number of channels
-f data format s16le s representatives numeral 16 denotes a numerical value represented by each of the 16 le expressed as little end head storage

gensees-iMac:study gensee$ ffmpeg -i out.flv -vn -ar 44100 -ac 2 -f s16le out.pcm
ffmpeg version N-94063-g86f04b918c Copyright (c) 2000-2019 the FFmpeg developers
  built with Apple LLVM version 8.1.0 (clang-802.0.38)
  configuration: --prefix=/usr/local/ffmpeg --enable-gpl --enable-nonfree --enable-libfdk-aac --enable-libx264 --enable-libx265 --enable-filter=delogo --enable-debug --disable-optimizations --enable-libspeex --enable-videotoolbox --enable-shared --enable-pthreads --enable-version3 --cc=clang --host-cflags= --host-ldflags=
  libavutil      56. 29.100 / 56. 29.100
  libavcodec     58. 53.100 / 58. 53.100
  libavformat    58. 27.103 / 58. 27.103
  libavdevice    58.  7.100 / 58.  7.100
  libavfilter     7. 55.100 /  7. 55.100
  libswscale      5.  4.101 /  5.  4.101
  libswresample   3.  4.100 /  3.  4.100
  libpostproc    55.  4.100 / 55.  4.100
Input #0, flv, from 'out.flv':
  Metadata:
    encoder         : Lavf58.27.103
  Duration: 00:00:08.13, start: 0.000000, bitrate: 470 kb/s
    Stream #0:0: Video: h264 (High 4:2:2), yuv422p(progressive), 1920x1080, 30 fps, 30 tbr, 1k tbn, 60 tbc
    Stream #0:1: Audio: aac (HE-AACv2), 44100 Hz, stereo, fltp, 32 kb/s
Stream mapping:
  Stream #0:1 -> #0:0 (aac (native) -> pcm_s16le (native))
Press [q] to stop, [?] for help
Output #0, s16le, to 'out.pcm':
  Metadata:
    encoder         : Lavf58.27.103
    Stream #0:0: Audio: pcm_s16le, 44100 Hz, stereo, s16, 1411 kb/s
    Metadata:
      encoder         : Lavc58.53.100 pcm_s16le
size=    1288kB time=00:00:08.13 bitrate=1296.4kbits/s speed= 203x    
video:0kB audio:1288kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.000000%
gensees-iMac:study gensee$ 

Play Audio

ffplay -ar 44100 -ac 2 -f s16le out.pcm

gensees-iMac:study gensee$ ffplay -ar 44100 -ac 2 -f s16le out.pcm
ffplay version N-94063-g86f04b918c Copyright (c) 2003-2019 the FFmpeg developers
  built with Apple LLVM version 8.1.0 (clang-802.0.38)
  configuration: --prefix=/usr/local/ffmpeg --enable-gpl --enable-nonfree --enable-libfdk-aac --enable-libx264 --enable-libx265 --enable-filter=delogo --enable-debug --disable-optimizations --enable-libspeex --enable-videotoolbox --enable-shared --enable-pthreads --enable-version3 --cc=clang --host-cflags= --host-ldflags=
  libavutil      56. 29.100 / 56. 29.100
  libavcodec     58. 53.100 / 58. 53.100
  libavformat    58. 27.103 / 58. 27.103
  libavdevice    58.  7.100 / 58.  7.100
  libavfilter     7. 55.100 /  7. 55.100
  libswscale      5.  4.101 /  5.  4.101
  libswresample   3.  4.100 /  3.  4.100
  libpostproc    55.  4.100 / 55.  4.100
[s16le @ 0x7fc51b876c00] Estimating duration from bitrate, this may be inaccurate
Input #0, s16le, from 'out.pcm':
  Duration: 00:00:07.48, bitrate: 1411 kb/s
    Stream #0:0: Audio: pcm_s16le, 44100 Hz, 2 channels, s16, 1411 kb/s
   5.88 M-A:  0.000 fd=   0 aq=  182KB vq=    0KB sq=    0B f=0/0   
gensees-iMac:study gensee$ 

Filter

Cut - to change the width and height

ffmpeg -i out.flv -vf crop=in_w-200:in_h-200 -c:v libx264 -c:a copy out.mp4

-i input file
-vf video filter chosen here crop filter
in_w in_h width and height representing the video

Add a watermark

ffmpeg -i out.mp4 -vf "movie=timg.jpeg,scale=70x30[watermask];[in][watermask] overlay=30:10 [out]" water.mp4

movie logo specified source
scale size specified logo
overlay specified logo placement

paste it here Piece of the watermark, in the upper left corner of the video

gensees-iMac:study gensee$ ffmpeg -i out.mp4 -vf "movie=timg.jpeg,scale=70x30[watermask];[in][watermask] overlay=30:10 [out]" water.mp4

After using ffplay play water.mp4 you can see the upper left corner there is a watermark

Deleting a watermark

ffplay -i water.mp4 -vf delogo=x=30:y=10:w=70:h=30:show=1 out.flv

Description of delogo filter:

• x, y: coordinates of the top left of the watermark
• Width and height of the watermark: w, h
• show: an optional parameter is 1, a green can be seen, the x, y, w h confirmed rectangular frame, to facilitate debugging. Correct, this parameter can be removed.
• To use delogo filters, compiled ffmpge must add -enable-gpl option. Or you will be prompted when using the
  
  upper-left corner for the watermark position

Audio and video cropping

ffmpeg -i out.flv -ss 00:00:00 -t 10 out.ts

-ss start second start time
-t time the size of the cut, cropped 10s here

Audio and video merge

ffmpeg -f concat -i inputs.txt out.flv

concat represent stitching
input.txt is a list of files, which reads 'file filename' format
if there are two ts files 1.ts 2.ts
then the content is input.txt

file '1.ts'
file '2.ts'

Video pictures Huzhuan

Video to picture

ffmpeg -i out.flv -r 1 -f image2 image-%3d.jpeg

1 frame per second frame rate -r
-f format means the format

After the terminal do you get picture

Pictures turn video

ffmpeg -i image-%3d.jpeg imageOut.mp4

The last 10 drawing to MP4
video after obtained using ffplay play