Count GOP (Group Of Pictures) and their frames (I, P and B frames) within a video file

probe_gop.sh

#!/usr/bin/env bash

set -e

GOP=0
iframes=0
totiframes=0
pframes=0
totpframes=0
bframes=0
totbframes=0
while IFS= read -r line; do
        if echo "$line" | grep -q 'frame,I'; then
                if [ $GOP -ne 0 ]; then
                        echo "GOP #${GOP} has $(( $iframes + $pframes + $bframes )) frames: $iframes I frame(s), $pframes P frames and $bframes B frames"
                fi
                totiframes=$(( $totiframes + $iframes ))
                iframes=1
                totpframes=$(( $totpframes + $pframes ))
                pframes=0
                totbframes=$(( $totbframes + $bframes ))
                bframes=0
                GOP=$(( $GOP + 1 ))
                continue
        fi
        if echo "$line" | grep -q 'frame,P'; then
                pframes=$(( $pframes + 1 ))
                continue
        fi
        if echo "$line" | grep -q 'frame,B'; then
                bframes=$(( $bframes + 1 ))
                continue
        fi
        echo "unexpected line: $line"
done < <(ffprobe -loglevel error -threads $(nproc) -select_streams v -show_frames -show_entries 'frame=pict_type' -of csv "$1")
echo "GOP #$GOP has $(( $iframes + $pframes + $bframes )) frames: $iframes I frame(s), $pframes P frames and $bframes B frames"
totiframes=$(( $totiframes + $iframes ))
totpframes=$(( $totpframes + $pframes ))
totbframes=$(( $totbframes + $bframes ))
echo
echo "Analysis done: $GOP Groups Of Pictures with $(( $totiframes + $totpframes + $totbframes )) total frames ($totiframes I frames, $totpframes P frames and $totbframes B frames)"