====== ffmpeg - Video - Size ======

===== Using Perl Regex =====

<code bash>
ffmpeg -i "input.mkv" -c copy -f null /dev/null 2>&1 | tail -n 2 | grep -Po "(?<=video\:)([0-9]+)"

or

ffmpeg -i "input.mkv" -c copy -f null /dev/null 2>&1 | tail -n 2 | grep -Po "video\:([0-9]+)(?=kB)" | cut -f 2 -d ":
</code>

<WRAP info>
**NOTE:**  Gets the size directly from ffmpeg.
</WRAP>


----

===== Get the video size from the stream =====

<code bash>
ffprobe -v error -select_streams v:$i -show_entries stream=size -of default=noprint_wrappers=1:nokey=1 "input.mkv" | uniq
</code>

<WRAP important>
**WARNING:**  This often returns N/A for some container formats, such as MKV.
</WRAP>

----

===== Get the video size from the container =====

<code bash>
ffprobe -v error -select_streams v:0 -show_entries format=size -of default=noprint_wrappers=1:nokey=1 "input.mkv" | uniq
</code>

<WRAP important>
**WARNING:**  This gets the entire container size, not just the video stream...
</WRAP>

----

===== Calculate video size manually using packet size =====

This method reads each video packet, individually, and totals up each packet size.

  * Sums up the **size** attribute of **-show_entries** command.

<code bash>
video_sizes=$(ffprobe -v error -select_streams v:0 -skip_frame nokey -show_entries packet=size -of default=nokey=1:noprint_wrappers=1 "input.mkv")

sum_video_size=0
precision=6
count_video_pkt_size=0

echo "Calculating video size..."
for video_size in $video_sizes; do
  (( sum_video_size+=video_size ))

  (( count_video_size++ ))
done;

size=$( echo "scale=6; ${sum_video_size}" | bc)
</code>

<WRAP info>
**NOTE:**  This is very accurate but may be slow...
</WRAP>

----