Ffmpeg usage in video compression processing

0、 Through the video compression function , Compress the video frame rate

First of all, we should understand that video is composed of pictures , For example, we can tell by the naked eye every second 24 About a picture , That is, when it plays us every second 24 More than pictures , We can't tell if it's a picture , It feels like a continuous action , This is the video , And normal videos, whether we record them ourselves , It is also a common video format , Frame rates are higher than 25 Frame above ,

Therefore, the content of this section is to count the video frames , Down to 10 Frames per second , This reduces the size of the video , Video compression

Of course, there are many ways of video compression , This is only the more common and easy to implement method .

Can pass python command , Change to python Script , All changes are inseparable from the root

os.system("ffmpeg XXXX")

perhaps

import subprocess
(status, output) = subprocess.getstatusoutput("ffmpeg XXXX")

In the end python The code batch processes the video

One 、ffmpeg install

Because of the present win10 The system can be installed Ubuntu Subsystem , Therefore, most of my software has been installed in Ubuntu In the subsystem , This is convenient for installation, operation and management , This article is about ffmpeg The examples of the video processing toolkit are all by Ubuntu complete .

Installation command
sudo apt install ffmpeg

Two 、 Compressed video

[email protected]:12_ Video processing $ ffmpeg -i "2.mp4" -r 10 -b:a 32k save2.mp4
among

command	meaning
-i "2.mp4"	Enter the video name as 2.mp4, Note the quotation marks
-r 10	Set up 10 frame /s
-b:a 32k	Set the audio bit rate to 32kb/s namely 4kB/s
save2.mp4	Set the output file name

effect

[email protected]:12_ Video processing $ ffmpeg -i "2.mp4" -r 10 -b:a 32k save2.mp4
ffmpeg version 3.4.6-0ubuntu0.18.04.1 Copyright (c) 2000-2019 the FFmpeg developers
  built with gcc 7 (Ubuntu 7.3.0-16ubuntu3)
  configuration: --prefix=/usr --extra-version=0ubuntu0.18.04.1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --enable-gpl --disable-stripping --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librubberband --enable-librsvg --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-omx --enable-openal --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libopencv --enable-libx264 --enable-shared
  libavutil      55. 78.100 / 55. 78.100
  libavcodec     57.107.100 / 57.107.100
  libavformat    57. 83.100 / 57. 83.100
  libavdevice    57. 10.100 / 57. 10.100
  libavfilter     6.107.100 /  6.107.100
  libavresample   3.  7.  0 /  3.  7.  0
  libswscale      4.  8.100 /  4.  8.100
  libswresample   2.  9.100 /  2.  9.100
  libpostproc    54.  7.100 / 54.  7.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '2.mp4':
  Metadata:
    major_brand     : mp42
    minor_version   : 0
    compatible_brands: mp41isom
    creation_time   : 2020-03-10T13:12:18.000000Z
    title           :  Neural vectorization : End to end depth vectorization reinforcement learning  - OneNote
    artist          : Microsoft Game DVR
  Duration: 00:00:06.51, start: 0.000000, bitrate: 8795 kb/s
    Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 8675 kb/s, 29.69 fps, 60 tbr, 30k tbn, 59.94 tbc (default)
    Metadata:
      creation_time   : 2020-03-10T13:12:18.000000Z
      handler_name    : VideoHandler
      encoder         : AVC Coding
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 120 kb/s (default)
    Metadata:
      creation_time   : 2020-03-10T13:12:18.000000Z
      handler_name    : SoundHandler
Stream mapping:
  Stream #0:0 -> #0:0 (h264 (native) -> h264 (libx264))
  Stream #0:1 -> #0:1 (aac (native) -> aac (native))
Press [q] to stop, [?] for help
[libx264 @ 0x7fffdff91780] using SAR=1/1
[libx264 @ 0x7fffdff91780] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 BMI2 AVX2
[libx264 @ 0x7fffdff91780] profile High, level 4.0
[libx264 @ 0x7fffdff91780] 264 - core 152 r2854 e9a5903 - H.264/MPEG-4 AVC codec - Copyleft 2003-2017 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=12 lookahead_threads=2 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=10 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
Output #0, mp4, to 'save2.mp4':
  Metadata:
    major_brand     : mp42
    minor_version   : 0
    compatible_brands: mp41isom
    artist          : Microsoft Game DVR
    title           :  Neural vectorization : End to end depth vectorization reinforcement learning  - OneNote
    encoder         : Lavf57.83.100
    Stream #0:0(und): Video: h264 (libx264) (avc1 / 0x31637661), yuv420p(progressive), 1920x1080 [SAR 1:1 DAR 16:9], q=-1--1, 10 fps, 10240 tbn, 10 tbc (default)
    Metadata:
      creation_time   : 2020-03-10T13:12:18.000000Z
      handler_name    : VideoHandler
      encoder         : Lavc57.107.100 libx264
    Side data:
      cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: -1
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 32 kb/s (default)
    Metadata:
      creation_time   : 2020-03-10T13:12:18.000000Z
      handler_name    : SoundHandler
      encoder         : Lavc57.107.100 aac
frame=   67 fps= 48 q=-1.0 Lsize=     455kB time=00:00:06.50 bitrate= 573.0kbits/s dup=0 drop=126 speed=4.62x
video:425kB audio:26kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.987973%
[libx264 @ 0x7fffdff91780] frame I:1     Avg QP:14.29  size:327526
[libx264 @ 0x7fffdff91780] frame P:20    Avg QP:19.98  size:  4573
[libx264 @ 0x7fffdff91780] frame B:46    Avg QP:23.36  size:   336
[libx264 @ 0x7fffdff91780] consecutive B-frames:  3.0% 14.9%  4.5% 77.6%
[libx264 @ 0x7fffdff91780] mb I  I16..4: 50.0%  9.9% 40.1%
[libx264 @ 0x7fffdff91780] mb P  I16..4:  0.9%  0.5%  0.0%  P16..4:  8.3%  0.2%  0.2%  0.0%  0.0%    skip:89.8%
[libx264 @ 0x7fffdff91780] mb B  I16..4:  0.1%  0.1%  0.0%  B16..8:  3.8%  0.0%  0.0%  direct: 0.1%  skip:95.8%  L0:18.6% L1:81.4% BI: 0.0%
[libx264 @ 0x7fffdff91780] 8x8 transform intra:17.3% inter:50.2%
[libx264 @ 0x7fffdff91780] coded y,uvDC,uvAC intra: 22.2% 32.8% 26.3% inter: 0.6% 2.0% 0.9%
[libx264 @ 0x7fffdff91780] i16 v,h,dc,p: 80% 20%  0%  0%
[libx264 @ 0x7fffdff91780] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 27%  4% 69%  0%  0%  0%  0%  0%  0%
[libx264 @ 0x7fffdff91780] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 35% 31% 12%  3%  3%  3%  4%  4%  5%
[libx264 @ 0x7fffdff91780] i8c dc,h,v,p: 67% 13% 18%  1%
[libx264 @ 0x7fffdff91780] Weighted P-Frames: Y:0.0% UV:0.0%
[libx264 @ 0x7fffdff91780] ref P L0: 82.5%  1.5% 14.5%  1.6%
[libx264 @ 0x7fffdff91780] ref B L0: 75.7% 23.1%  1.2%
[libx264 @ 0x7fffdff91780] ref B L1: 97.0%  3.0%
[libx264 @ 0x7fffdff91780] kb/s:518.72
[aac @ 0x7fffdff9b9c0] Qavg: 574.607
[email protected]:12_ Video processing $                   

3、 ... and 、 Common commands

0.  Remove sounds for a specified period of time ,  here between t Time 0-237s All sounds between are deleted 
ffmpeg -i temperature.mp4 -af "volume=enable='between(t,0,237)':volume=0" out.mp4

1. Separate video and audio streams 

ffmpeg -i input_file -vcodec copy -an output_file_video　　// Separate video streams 
ffmpeg -i input_file -acodec copy -vn output_file_audio　　// Separate audio streams 

2. Video demultiplexing 

ffmpeg –i test.mp4 –vcodec copy –an –f m4v test.264
ffmpeg –i test.avi –vcodec copy –an –f m4v test.264

3. Video transcoding 

ffmpeg –i test.mp4 –vcodec h264 –s 352*278 –an –f m4v test.264              // Transcoding is the original file of code stream 
ffmpeg –i test.mp4 –vcodec h264 –bf 0 –g 25 –s 352*278 –an –f m4v test.264  // Transcoding is the original file of code stream 
ffmpeg –i test.avi -vcodec mpeg4 –vtag xvid –qsame test_xvid.avi            // Transcoding to encapsulation file 
//-bf B Frame number control ,-g  Keyframe interval control ,-s  Resolution control 

4. Video packaging 

ffmpeg –i video_file –i audio_file –vcodec copy –acodec copy output_file

5. Video clip 

ffmpeg –i test.avi –r 1 –f image2 image-%3d.jpeg        // To extract the image 
ffmpeg -ss 0:1:30 -t 0:0:20 -i input.avi -vcodec copy -acodec copy output.avi    // Cut video 
//-r  Extract the frequency of the image ,-ss  Starting time ,-t  The duration of the 

6. video recording 

ffmpeg –i rtsp://192.168.3.205:5555/test –vcodec copy out.avi

7.YUV Sequence play 

ffplay -f rawvideo -video_size 1920x1080 input.yuv

8.YUV The sequence turns AVI

ffmpeg –s w*h –pix_fmt yuv420p –i input.yuv –vcodec mpeg4 output.avi

9. Get the cover 
ffmpeg -ss 00:00:10 -i test1.flv -f image2 -y test1.jpg



 Description of common parameters ：

 main parameter ：
-i  Set input flow 
-f  Set output format 
-ss  Starting time 
 Video parameters ：
-b  Set video traffic , The default is 200Kbit/s
-r  Set the frame rate , The default is 25
-s  Set the width and height of the screen 
-aspect  Set the scale of the screen 
-vn  Don't process video 
-vcodec  Set the video codec , If it is not set, the same codec as the input stream will be used 
 Audio parameters ：
-ar  Set the sampling rate 
-ac  Set the sound Channel Count 
-acodec  Set up the sound codec , If it is not set, the same codec as the input stream will be used 
-an  Don't handle audio 

-L license

-h  help 

-fromats  Show available formats , Codec , Agreed ...

-f fmt  Force format fmt

-I filename  Input file 

-y  Overwrite output file 

-t duration  Set the recording time  hh:mm:ss[.xxx] The format of recording time also supports 

-ss position  Search to the specified time  [-]hh:mm:ss[.xxx] The format also supports 

-title string  Set title 

-author string  Set the author 

-copyright string  Set copyright 

-comment string  Set up comments 

-target type  Set the target file type (vcd,svcd,dvd)  All the format options （ Bit rate , Codec and buffer size ） Automatic setting  , Just type in the following ：
ffmpeg -i myfile.avi -target vcd /tmp/vcd.mpg

-hq  Activate high quality settings 

-itsoffset offset  Set the time offset in seconds , This option affects all subsequent input files . The offset is added to the timestamp of the input file , Defining a positive offset means that the corresponding stream is delayed  offset second . [-]hh:mm:ss[.xxx] The format also supports 

Four 、 Code

#  The function of the script is ,  All videos in the folder to be compressed ,  adopt ffmpeg
#  Frame rate compression ,  Save the compressed file to the processed folder 
#  The execution order is   In the installation ffmpeg In the system , python passion.py
import os
import sys


wait_handle_dir = r" To be compressed /"
save_dir = r" processed /"
if os.path.exists(save_dir):
    pass
else:
    os.mkdir(save_dir)


for file in os.listdir(wait_handle_dir):
    save_name = f"{os.path.splitext(file)[0]}.mp4"
    if save_name not in os.listdir(save_dir): #  Judge whether there is converted data in the folder 
        print(f"trackle {wait_handle_dir}{file} ..................................")
        os.system(f'ffmpeg -i "{wait_handle_dir}{file}" -r 10 -b:a 32k "{save_dir}{save_name}"')

update 2020/9/17 Add parallel processing

# passion.py
#  The function of the script is ,  All videos in the folder to be compressed ,  adopt ffmpeg
#  Frame rate compression ,  Save the compressed file to the processed folder 
#  The execution order is   In the installation ffmpeg In the system , python passion.py  Folder of video to be compressed 
import os
import sys
import ray #  If there is an error here ,  Please install ray package  pip install ray
import time
time_now = time.time()

wait_handle_dir = str(sys.argv[1])
if "/" not in wait_handle_dir:
	wait_handle_dir = wait_handle_dir+"/"

save_dir = wait_handle_dir[:-1] + "_handle/"
print(f" The results will be saved to the path {save_dir} Inside ")

if os.path.exists(save_dir):
    pass
else:
    os.mkdir(save_dir)

ray.init()
@ray.remote
def handle_single(file):
    save_name = f"{os.path.splitext(file)[0]}.mp4"
    if save_name not in os.listdir(save_dir): #  Judge whether there is converted data in the folder 
        print(f"trackle {wait_handle_dir}{file} ..................................")
        os.system(f'ffmpeg -i "{wait_handle_dir}{file}" -r 10 -b:a 32k "{save_dir}{save_name}"')

ray.get([handle_single.remote(file) for file in os.listdir(wait_handle_dir)]) 
#  Process all files in parallel ,  The speed depends on the computer CPU Number of cores ,  Such as four cores and eight threads   Then eight files will be processed at one time, no more words 

print(" when :", time.time()-time_now)

Here are some links that summarize common commands
ffmpeg Command parameter details
Video compression tools ffmpeg Use
python Video compression