How to extract duration time from ffmpeg output?

To get a lot of information about a media file one can do

ffmpeg -i <filename>

where it will output a lot of lines, one in particular

Duration: 00:08:07.98, start: 0.000000, bitrate: 2080 kb/s

I would like to output only 00:08:07.98, so I try

ffmpeg -i file.mp4 | grep Duration| sed 's/Duration: \(.*\), start/\1/g'

But it prints everything, and not just the length.

Even ffmpeg -i file.mp4 | grep Duration outputs everything.

How do I get just the duration length?

Solution 1:

You can use ffprobe:

ffprobe -i <file> -show_entries format=duration -v quiet -of csv="p=0"

It will output the duration in seconds, such as:

154.12

Adding the -sexagesimal option will output duration as hours:minutes:seconds.microseconds:

00:02:34.12

Solution 2:

ffmpeg is writing that information to stderr, not stdout. Try this:

ffmpeg -i file.mp4 2>&1 | grep Duration | sed 's/Duration: \(.*\), start/\1/g'

Notice the redirection of stderr to stdout: 2>&1

EDIT:

Your sed statement isn't working either. Try this:

ffmpeg -i file.mp4 2>&1 | grep Duration | awk '{print $2}' | tr -d ,

Solution 3:

From my experience many tools offer the desired data in some kind of a table/ordered structure and also offer parameters to gather specific parts of that data. This applies to e.g. smartctl, nvidia-smi and ffmpeg/ffprobe, too. Simply speaking - often there's no need to pipe data around or to open subshells for such a task.

As a consequence I'd use the right tool for the job - in that case ffprobe would return the raw duration value in seconds, afterwards one could create the desired time format on his own:

$ ffmpeg --version
ffmpeg version 2.2.3 ...

The command may vary dependent on the version you are using.

#!/usr/bin/env bash
input_file="/path/to/media/file"

# Get raw duration value
ffprobe -v quiet -print_format compact=print_section=0:nokey=1:escape=csv -show_entries format=duration "$input_file"

An explanation:

"-v quiet": Don't output anything else but the desired raw data value

"-print_format": Use a certain format to print out the data

"compact=": Use a compact output format

"print_section=0": Do not print the section name

":nokey=1": do not print the key of the key:value pair

":escape=csv": escape the value

"-show_entries format=duration": Get entries of a field named duration inside a section named format

Reference: ffprobe man pages

Solution 4:

I recommend using json format, it's easier for parsing

ffprobe -i your-input-file.mp4 -v quiet -print_format json -show_format -show_streams -hide_banner

{
    "streams": [
        {
            "index": 0,
            "codec_name": "aac",
            "codec_long_name": "AAC (Advanced Audio Coding)",
            "profile": "HE-AACv2",
            "codec_type": "audio",
            "codec_time_base": "1/44100",
            "codec_tag_string": "[0][0][0][0]",
            "codec_tag": "0x0000",
            "sample_fmt": "fltp",
            "sample_rate": "44100",
            "channels": 2,
            "channel_layout": "stereo",
            "bits_per_sample": 0,
            "r_frame_rate": "0/0",
            "avg_frame_rate": "0/0",
            "time_base": "1/28224000",
            "duration_ts": 305349201,
            "duration": "10.818778",
            "bit_rate": "27734",
            "disposition": {
                "default": 0,
                "dub": 0,
                "original": 0,
                "comment": 0,
                "lyrics": 0,
                "karaoke": 0,
                "forced": 0,
                "hearing_impaired": 0,
                "visual_impaired": 0,
                "clean_effects": 0,
                "attached_pic": 0
            }
        }
    ],
    "format": {
        "filename": "your-input-file.mp4",
        "nb_streams": 1,
        "nb_programs": 0,
        "format_name": "aac",
        "format_long_name": "raw ADTS AAC (Advanced Audio Coding)",
        "duration": "10.818778",
        "size": "37506",
        "bit_rate": "27734",
        "probe_score": 51
    }
}

you can find the duration information in format section, works both for video and audio