ari_stitch() image path on win + RStudio

[CorradoLanera]

The call to ffmpeg concat attaches the wd to each filepath (at least on my system). I solved by reset
images <- basename(images) just before the loop on input_txt_path.

Here below the reprex after the patch I used to fix issue #2

ari::ari_narrate(
  script = system.file("test", "ari_intro_script.md", package = "ari"),
  slides = system.file("test", "ari_intro.html", package = "ari"),
  voice  = "Joey"
)
#> "C:/Program Files/RStudio/bin/pandoc/pandoc" +RTS -K512m -RTS ari_intro_script.utf8.md --to html --from markdown+autolink_bare_uris+ascii_identifiers+tex_math_single_backslash --output pandoc1c0c414b4119.html --smart --email-obfuscation none --self-contained --standalone --section-divs --template "C:\Users\corra\Documents\R\win-library\3.4\rmarkdown\rmd\h\default.html" --no-highlight --variable highlightjs=1 --variable "theme:bootstrap" --include-in-header "C:\Users\corra\AppData\Local\Temp\RtmpCiyuCW\rmarkdown-str1c0c69c45021.html" --mathjax --variable "mathjax-url:https://mathjax.rstudio.com/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML"
#> 
#> Output created: C:\Users\corra\AppData\Local\Temp\Rtmpi8VlWj/ari_script_Sr4gMM78ULl4.html
#> Warning in normalizePath(path.expand(path), winslash, mustWork):
#> path[1]="C:\Users\corra\Documents\R\win-library\3.4\ari\test
#> \ari_intro.html#1": The system cannot find the file specified
#> Warning in normalizePath(path.expand(path), winslash, mustWork):
#> path[1]="C:\Users\corra\Documents\R\win-library\3.4\ari\test
#> \ari_intro.html#2": The system cannot find the file specified
#> Warning in normalizePath(path.expand(path), winslash, mustWork):
#> path[1]="C:\Users\corra\Documents\R\win-library\3.4\ari\test
#> \ari_intro.html#3": The system cannot find the file specified
#> Warning in normalizePath(path.expand(path), winslash, mustWork):
#> path[1]="C:\Users\corra\Documents\R\win-library\3.4\ari\test
#> \ari_intro.html#4": The system cannot find the file specified
#> Warning in normalizePath(path.expand(path), winslash, mustWork):
#> path[1]="C:\Users\corra\Documents\R\win-library\3.4\ari\test
#> \ari_intro.html#5": The system cannot find the file specified
#> Warning: running command 'C:\ffmpeg\bin\ffmpeg.exe -y -f concat -safe 0 -
#> i C:\Users\corra\AppData\Local\Temp\Rtmpi8VlWj/ari_input_LcPVQ5rUzxVj.txt -
#> i C:\Users\corra\AppData\Local\Temp\Rtmpi8VlWj/ari_audio_F5L1gjRHbCnw.wav
#> -c:v libx264 -c:a aac -b:a 192k -shortest -vsync vfr -pix_fmt yuv420p
#> output.mp4' had status 1

Session info

devtools::session_info()
#> Session info -------------------------------------------------------------
#>  setting  value                       
#>  version  R version 3.4.2 (2017-09-28)
#>  system   x86_64, mingw32             
#>  ui       RTerm                       
#>  language (EN)                        
#>  collate  English_United States.1252  
#>  tz       Europe/Berlin               
#>  date     2017-10-08
#> Packages -----------------------------------------------------------------
#>  package       * version  date       source        
#>  ari             0.1.0    2017-10-07 local         
#>  assertthat      0.2.0    2017-04-11 CRAN (R 3.4.1)
#>  aws.polly       0.1.2    2016-12-08 CRAN (R 3.4.1)
#>  aws.signature   0.3.5    2017-07-01 CRAN (R 3.4.1)
#>  backports       1.1.0    2017-05-22 CRAN (R 3.4.0)
#>  base          * 3.4.2    2017-09-28 local         
#>  base64enc       0.1-3    2015-07-28 CRAN (R 3.4.0)
#>  compiler        3.4.2    2017-09-28 local         
#>  curl            2.8.1    2017-07-21 CRAN (R 3.4.1)
#>  datasets      * 3.4.2    2017-09-28 local         
#>  devtools        1.13.3   2017-08-02 CRAN (R 3.4.1)
#>  digest          0.6.12   2017-01-27 CRAN (R 3.4.1)
#>  evaluate        0.10.1   2017-06-24 CRAN (R 3.4.1)
#>  graphics      * 3.4.2    2017-09-28 local         
#>  grDevices     * 3.4.2    2017-09-28 local         
#>  htmltools       0.3.6    2017-04-28 CRAN (R 3.4.1)
#>  httr            1.3.1    2017-08-20 CRAN (R 3.4.1)
#>  jsonlite        1.5      2017-06-01 CRAN (R 3.4.1)
#>  knitr           1.17     2017-08-10 CRAN (R 3.4.1)
#>  magrittr        1.5      2014-11-22 CRAN (R 3.4.1)
#>  MASS            7.3-47   2017-04-21 CRAN (R 3.4.1)
#>  memoise         1.1.0    2017-04-21 CRAN (R 3.4.1)
#>  methods       * 3.4.2    2017-09-28 local         
#>  prettyunits     1.0.2    2015-07-13 CRAN (R 3.4.1)
#>  progress        1.1.2    2016-12-14 CRAN (R 3.4.1)
#>  purrr           0.2.3    2017-08-02 CRAN (R 3.4.1)
#>  R6              2.2.2    2017-06-17 CRAN (R 3.4.1)
#>  Rcpp            0.12.12  2017-07-15 CRAN (R 3.4.1)
#>  rlang           0.1.2    2017-08-09 CRAN (R 3.4.1)
#>  rmarkdown       1.6      2017-06-15 CRAN (R 3.4.1)
#>  rprojroot       1.2      2017-01-16 CRAN (R 3.4.1)
#>  rvest           0.3.2    2016-06-17 CRAN (R 3.4.1)
#>  selectr         0.3-1    2016-12-19 CRAN (R 3.4.1)
#>  signal          0.7-6    2015-07-30 CRAN (R 3.4.1)
#>  stats         * 3.4.2    2017-09-28 local         
#>  stringi         1.1.5    2017-04-07 CRAN (R 3.4.0)
#>  stringr         1.2.0    2017-02-18 CRAN (R 3.4.1)
#>  tools           3.4.2    2017-09-28 local         
#>  tuneR           1.3.2    2017-04-10 CRAN (R 3.4.1)
#>  utils         * 3.4.2    2017-09-28 local         
#>  webshot         0.4.2    2017-09-25 CRAN (R 3.4.2)
#>  withr           2.0.0    2017-07-28 CRAN (R 3.4.1)
#>  XML             3.98-1.9 2017-06-19 CRAN (R 3.4.0)
#>  xml2            1.1.1    2017-01-24 CRAN (R 3.4.1)
#>  yaml            2.1.14   2016-11-12 CRAN (R 3.4.1)

While running not for reprex, the error is more informative and, in particular the following is the output of my consol

ffmpeg version 3.3.3 Copyright (c) 2000-2017 the FFmpeg developers
  built with gcc 7.1.0 (GCC)
  configuration: --enable-gpl --enable-version3 --enable-cuda --enable-cuvid --enable-d3d11va --enable-dxva2 --enable-libmfx --enable-nvenc --enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libfreetype --enable-libgme --enable-libgsm --enable-libilbc --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenh264 --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-libzimg --enable-lzma --enable-zlib
  libavutil      55. 58.100 / 55. 58.100
  libavcodec     57. 89.100 / 57. 89.100
  libavformat    57. 71.100 / 57. 71.100
  libavdevice    57.  6.100 / 57.  6.100
  libavfilter     6. 82.100 /  6. 82.100
  libswscale      4.  6.100 /  4.  6.100
  libswresample   2.  7.100 /  2.  7.100
  libpostproc    54.  5.100 / 54.  5.100
[concat @ 00000000006128a0] Impossible to open 'C:\Users\corra\OneDrive\miscR\ari_video_slide/C:\Users\corra\OneDrive\miscR\ari_video_slide\ari_img_1_L810ChiVwf14p.jpeg'
C:\Users\corra\OneDrive\miscR\ari_video_slide/ari_input_mKfvdbvsyVSq.txt: Invalid argument

As you can see the filepath is repeated twice.