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Precisa de ajuda com o script bash MPV

tag-icon • tag-icon bash screenshot filename
Precisa de ajuda com o script bash MPV

Basicamente, estou tentando editar um script bash. O objetivo do script é permitir que eu faça várias capturas de tela de vídeos simplesmente iniciando-o no terminal, bastando especificar o nome do arquivo e o número da captura de tela desejada. Resolvi alguns bugs, mas estou tendo problemas para fazer com que o MPV atribua o nome de arquivo desejado.

Aqui está o script como está atualmente.

#!/bin/bash


### Global variables
filename="$1"

### Error handling
if [ -z ${filename} ]; 
then
    echo "ERROR: No video file supplied. Please enter a video file as argument."
    exit 1;
fi

NUM_OF_SCREENSHOTS=9
if [ ! -z $2 ]; 
then
  NUM_OF_SCREENSHOTS=$2
  echo "WARNING: Overwrite default number of screenshots to ${NUM_OF_SCREENSHOTS}."
  sleep 3s
fi




# Get the total length of the video in seconds.
#  Use mplayer to display the info of the video and then get the value of ID_LENGTH, the total number of seconds of the video.
total_length=$(mplayer -identify -frames 0 -vc null -vo null -ao null "$filename" | grep ID_LENGTH | sed 's/ID_LENGTH=//' | sed 's/\..*//')
# Reference https://github.com/mpv-player/mpv/blob/master/TOOLS/mpv_identify.sh

# Remove 4 seconds from the video so that it doesn't take screenshot at the ends.
let total_length-=4

# time_slice: At which time interval should mplayer take screenshots.
let time_slice=${total_length}/${NUM_OF_SCREENSHOTS}

# time_at: When should mplayer take screenshots.
time_at=${time_slice};

# Looping to take screenshots.
for ((i=1; i <= NUM_OF_SCREENSHOTS ; i++))
do


  # Take the screenshot.
  #mplayer -loop 1 -nosound -frames 1 -ss ${time_at} -vo png:z=9 ${filename}
  mpv --quiet --no-audio --vo=image --screenshot-template="%f %n" --start=${time_at} --frames=1 "$filename" 

  # Increment to the next time slice.
  let time_at+=${time_slice}



done

Responder1

O script não pode funcionar dessa maneira. O script está basicamente bom, embora você deva fazer pequenas melhorias (useShellCheckpor isso.)

O problema é que mpvusa um contador interno para nomear o arquivo de captura de tela ( %n). E o contador é zerado a cada passagem do loop.

O script modificado abaixo renomeia o arquivo.

#!/usr/bin/env bash

### Global variables
filename="$1"

### Error handling
if [ -z "${filename}" ]; 
then
    echo "ERROR: No video file supplied. Please enter a video file as argument."
    exit 1;
fi

NUM_OF_SCREENSHOTS=9
if [ ! -z "$2" ]; 
then
  NUM_OF_SCREENSHOTS=$2
  echo "WARNING: Overwrite default number of screenshots to ${NUM_OF_SCREENSHOTS}."
  sleep 3s
fi

# Get the total length of the video in seconds.
#  Use mplayer to display the info of the video and then get the value of ID_LENGTH, the total number of seconds of the video.
total_length=$(mplayer -identify -frames 0 -vc null -vo null -ao null "$filename" | grep ID_LENGTH | sed 's/ID_LENGTH=//' | sed 's/\..*//')
# Reference https://github.com/mpv-player/mpv/blob/master/TOOLS/mpv_identify.sh

# Remove 4 seconds from the video so that it doesn't take screenshot at the ends.
let total_length-=4

# time_slice: At which time interval should mplayer take screenshots.
let time_slice=${total_length}/${NUM_OF_SCREENSHOTS}

# time_at: When should mplayer take screenshots.
time_at=${time_slice};

# Looping to take screenshots.
for ((i=1; i <= NUM_OF_SCREENSHOTS ; i++))
do

  # Take the screenshot.
  #mplayer -loop 1 -nosound -frames 1 -ss ${time_at} -vo png:z=9 ${filename}
  mpv --quiet --no-audio --vo=image --start=${time_at} --frames=1 "$filename" 
  rename 's/^[0-9]+/out'"${time_at}"'/' 00000001.jpg

  # Increment to the next time slice.
  let time_at+=${time_slice}

done

exit 0

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