| 1 | #!/usr/bin/env bash |
| 2 | |
| 3 | get_audio_format() { |
| 4 | # Desc: Gets audio format of file as string |
| 5 | # Usage: get_audio_format arg1 |
| 6 | # Depends: ffprobe |
| 7 | # Version: 0.0.1 |
| 8 | # Input: arg1: input file path |
| 9 | # Output: stdout (if valid audio format) |
| 10 | # exit code 0 if audio file; 1 otherwise |
| 11 | # Example: get_audio_format myvideo.mp4 |
| 12 | # Note: Would return "opus" if full ffprobe report had 'Audio: opus, 48000 Hz, stereo, fltp' |
| 13 | # Note: Not tested with videos containing multiple video streams |
| 14 | # Ref/Attrib: [1] https://stackoverflow.com/questions/5618363/is-there-a-way-to-use-ffmpeg-to-determine-the-encoding-of-a-file-before-transcod |
| 15 | # [2] https://stackoverflow.com/questions/44123532/how-to-find-out-the-file-extension-for-extracting-audio-tracks-with-ffmpeg-and-p#comment88464070_50723126 |
| 16 | local audio_format file_in; |
| 17 | local return_state; |
| 18 | file_in="$1"; |
| 19 | |
| 20 | # Return error exit code if not audio file |
| 21 | ## Return error if ffprobe itself exited on error |
| 22 | if ! ffprobe -v error -select_streams a -show_entries stream=codec_name -of default=nokey=1:noprint_wrappers=1 "$file_in" 1>/dev/null 2>&1; then |
| 23 | return_state="false"; |
| 24 | fi; |
| 25 | |
| 26 | # Get audio format |
| 27 | audio_format="$(ffprobe -v error -select_streams a -show_entries stream=codec_name -of default=nokey=1:noprint_wrappers=1 "$file_in")"; # see [1] |
| 28 | |
| 29 | ## Return error if audio format is incorrectly formatted (e.g. reject if contains spaces) |
| 30 | pattern="^[[:alnum:]]+$"; # alphanumeric string with no spaces |
| 31 | if [[ $audio_format =~ $pattern ]]; then |
| 32 | return_state="true"; |
| 33 | # Report audio format |
| 34 | echo "$audio_format"; |
| 35 | else |
| 36 | return_state="false"; |
| 37 | fi; |
| 38 | |
| 39 | # Report exit code |
| 40 | if [[ $return_state = "true" ]]; then |
| 41 | return 0; |
| 42 | else |
| 43 | return 1; |
| 44 | fi; |
| 45 | } # Get audio format as stdout |
| 46 | |
| 47 | # Author: Steven Baltakatei Sandoval |
| 48 | # License: GPLv3+ |