#!/usr/bin/env bash

# GOP
# gop_with_graph

input="$1"

ffprobe -v error \
  -select_streams v:0 \
  -show_frames \
  -show_entries frame=pict_type,pkt_size \
  -of csv=p=0 "$input" |
awk -F',' '
{
    type=""
    size=0

    for (i=1; i<=NF; i++) {
        if ($i ~ /^[IPB]$/) type=$i
        if ($i ~ /^[0-9]+$/) size=$i
    }

    if (!type && size) type="I"

    if (type && size) {
        n++
        types[n]=type
        sizes[n]=size
        if (size > max) max=size
    }
}
END {
    width = 40   # max bar width

    for (i=1; i<=n; i++) {
        # padded symbol
        if (types[i]=="I") sym="I────"
        else if (types[i]=="P") sym="  P  "
        else sym="    B"

        # linear scale bar
        bar_len = int((sizes[i] / max) * width)
        # or log scaling
        # bar_len = int((log(sizes[i]+1) / log(max+1)) * width)
        bar = ""
        for (j=0; j<bar_len; j++) bar = bar "#"

        printf "%6d  %s  %8d bytes  %s\n", i, sym, sizes[i], bar
    }
}
'