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• ffmpeg : given a video of any length, create timelapse video of 6-8 seconds long

  14 mai 2018, par CDub

  I have an application which consumes video of any length (could be a few seconds, could be several minutes) and I want to use ffmpeg to return a "timelapse" version of the input video which will always be between 6 and 8 seconds long.

  I’ve been fiddling with the following :

  ffmpeg -y -i in.mp4 -r 10 -vf setpts='0.01*PTS' -an out.mp4

  Which seems to be a good start, but still generates very dynamic results given what in.mp4 is.

  I also don’t fully understand the verbiage in the ffmpeg documentation, so I’m not even sure what arguments to use for setpts, or if setpts is the correct filter I want to use.

• Live streaming .webm file with ffmpeg and nginx

  9 décembre 2017, par seekahead

  Hi I am new to ffmpeg and I need some help with live streaming of .webm file which is still being written into. I have a .webm file containing only video in vp9 codecwhich needs to be live streamed (preferably without transcoding and streamed using DASH`. I have compiled nginx along with nginx-ts-module from (https://github.com/arut/nginx-ts-module#features) with the following configuration

  nginx version: nginx/1.12.1
  
  built by gcc 4.8.4 (Ubuntu 4.8.4-2ubuntu1~14.04.3) 
  
  built with OpenSSL 1.0.1f 6 Jan 2014
  
  TLS SNI support enabled
  
  configure arguments: --with-cc-opt='-g -O2 -fPIE -fstack-protector --param=ssp-buffer-size=4 -Wformat -Werror=format-security -fPIC -D_FORTIFY_SOURCE=2' --with-ld-opt='-Wl,-Bsymbolic-functions -fPIE -pie -Wl,-z,relro -Wl,-z,now -fPIC' --prefix=/usr/share/nginx --conf-path=/etc/nginx/nginx.conf --http-log-path=/var/log/nginx/access.log --error-log-path=/var/log/nginx/error.log --lock-path=/var/lock/nginx.lock --pid-path=/run/nginx.pid --modules-path=/usr/lib/nginx/modules --http-client-body-temp-path=/var/lib/nginx/body --http-fastcgi-temp-path=/var/lib/nginx/fastcgi --http-proxy-temp-path=/var/lib/nginx/proxy --http-scgi-temp-path=/var/lib/nginx/scgi --http-uwsgi-temp-path=/var/lib/nginx/uwsgi --with-debug --with-pcre-jit --with-http_ssl_module --with-http_stub_status_module --with-http_realip_module --with-http_auth_request_module --with-http_v2_module --with-http_dav_module --with-http_slice_module --with-threads --with-http_addition_module --with-http_gunzip_module --with-http_gzip_static_module --with-http_sub_module --with-stream=dynamic --with-stream_ssl_module --with-stream_ssl_preread_module --with-mail=dynamic --with-mail_ssl_module --add-dynamic-module=/home/ubuntu/NGINX/nginx-ts-module-master

  The mediafile has the following properties(obtained with mediainfo) :

  General
  
  Complete name                            : video_4_1_Admin_0.webm
  
  Format                                   : WebM
  
  Format version                           : Version 2
  
  File size                                : 19.7 MiB
  
  Duration                                 : 1ms
  
  Overall bit rate                         : 165 Gbps
  
  Writing library                          : libwebm-0.2.1.0
  
  Video
  
  ID                                       : 1
  
  Format                                   : VP9
  
  Codec ID                                 : V_VP9
  
  Width                                    : 320 pixels
  
  Height                                   : 180 pixels
  
  Display aspect ratio                     : 16:9
  
  Frame rate mode                          : Variable
  
  Language                                 : English
  
  Default                                  : Yes
  
  Forced                                   : No

  I am trying to stream the file with the following

  ffmpeg -re -i video_4_1_Admin_0.webm -bsf:v vp9_superframe -c copy -f webm_chunk  http://127.0.0.1:8000/publish/sintel

  And I am getting the following error

  Input #0, matroska,webm, from 'video_4_1_Admin_0.webm':
  
    Metadata:
  
      encoder         : libwebm-0.2.1.0
  
    Duration: 00:00:00.00, start: 0.000000, bitrate: 174444152 kb/s
  
      Stream #0:0(eng): Video: vp9 (Profile 0), yuv420p(tv), 320x180, SAR 1:1 DAR 16:9, 30 fps, 30 tbr, 1k tbn, 1k tbc (default)
  
  Output #0, webm_chunk, to 'http://127.0.0.1:8000/publish/sintel':
  
  Output file #0 does not contain any stream

  I am not sure what are the exact options to be passed to ffmpeg so that it creates the .mpd and needed chunks which will allow me to LiveStream the media, I tried replacing the options given in the example (https://github.com/arut/nginx-ts-module#features) with what seems like vp9 equivalent., but, I am not sure. Can someone help me out here ? Thanks in advance

• Converting ffmpeg loudnorm first pass dcf summary report output to data.frame R

  23 décembre 2022, par Chris

  Following from operations on a video with ffmpeg, a loudnorm first pass report for purely audio files is produced

  


  names(aud_proc_df)
[1] "in_files" "proc_out" "filter"

cmds_loudness_report <- with(aud_proc_df, sprintf("ffmpeg -hide_banner -i %s -af loudnorm=I=-23:TP=-2:LRA=7:print_format=summary -f null /dev/null 2>&1 | tail -n 12 >> loudness_rpt_all.txt", in_files)) # linux specific notation
lapply(cmds_loudness_report, system)


  


  reading this as a .csv rather than .dcf

  


  loudness_df_csv <- read.csv('loudness_rpt_all.txt', header = FALSE, sep =':')
head(loudness_df_csv)
                 V1                  V2
1  Input Integrated          -24.7 LUFS
2   Input True Peak           -1.6 dBTP
3         Input LRA             17.9 LU
4   Input Threshold          -37.8 LUFS
5 Output Integrated          -23.4 LUFS
6  Output True Peak           -2.0 dBTP
#data
structure(list(V1 = c("Input Integrated", "Input True Peak", 
"Input LRA", "Input Threshold", "Output Integrated", "Output True Peak", 
"Output LRA", "Output Threshold", "Normalization Type", "Target Offset", 
"Input Integrated", "Input True Peak", "Input LRA", "Input Threshold", 
"Output Integrated", "Output True Peak", "Output LRA", "Output Threshold", 
"Normalization Type", "Target Offset"), V2 = c("    -24.7 LUFS", 
"      -1.6 dBTP", "            17.9 LU", "     -37.8 LUFS", 
"   -23.4 LUFS", "     -2.0 dBTP", "           14.8 LU", "    -36.2 LUFS", 
"   Dynamic", "        +0.4 LU", "    -23.9 LUFS", "      +0.2 dBTP", 
"            22.0 LU", "     -37.6 LUFS", "   -23.6 LUFS", "     -2.0 dBTP", 
"           21.9 LU", "    -37.0 LUFS", "   Dynamic", "        +0.6 LU"
)), row.names = c(NA, 20L), class = "data.frame")


  


  then, for column notation portability between win and linux systems

  


  df_names <- unique(loudness_df_csv$V1)
df_names2 <- gsub(' ', '_', df_names)


  


  and then make a data.frame

  


  loudnorm_rpt <- data.frame(loudness_df_csv$V2[which(loudness_df_csv$V1 == df_names[1])], loudness_df_csv$V2[which(loudness_df_csv$V1 == df_names[2])], loudness_df_csv$V2[which(loudness_df_csv$V1 == df_names[3])], loudness_df_csv$V2[which(loudness_df_csv$V1 == df_names[4])], loudness_df_csv$V2[which(loudness_df_csv$V1 == df_names[5])], loudness_df_csv$V2[which(loudness_df_csv$V1 == df_names[6])], loudness_df_csv$V2[which(loudness_df_csv$V1 == df_names[7])], loudness_df_csv$V2[which(loudness_df_csv$V1 == df_names[8])], loudness_df_csv$V2[which(loudness_df_csv$V1 == df_names[9])], loudness_df_csv$V2[which(loudness_df_csv$V1 == df_names[10])])
names(loudnorm_rpt) <- df_names2
rownames(loudnorm_rpt) <- c('A', 'B')


  


  Should I just wrap this in a function or is there a dcf to data.frame function that I've missed ?