VLC and ffprobe: inspect files before delivery

A review that produces useful notes

Record filename, content version, duration and requested destination. On Windows, Media → Open File opens the file and may begin playback: prepare a review screen and monitoring outside the audience output first.

In Tools → Codec Information, inspect the identified streams and compare the codec and resolution with the delivery brief. This guide’s metadata section shows how to obtain a repeatable technical report with ffprobe.

No sound, or the wrong track?

Check Audio → Audio Track: a track may be disabled or another language selected. Also check output device, mute and volume. Identify and listen to required tracks; track count and channel count are different.

If the video uses external audio or associated subtitles, include them in the delivery and check how they load at the destination. Check what is embedded in the video and what relies on separate files. Preserve the originals and record the exact file you opened.

Different picture, or the wrong destination?

Compare aspect ratio, cropping, playback speed, subtitles and active effects to identify the source of the difference. On Windows, Video → Full Screen fills the screen and Esc exits. Separately check that the picture is on the intended monitor without visible controls or desktop elements; fullscreen alone does not confirm those conditions.

Review text, motion, sync, start and end; for a loop, observe several restarts at the intended destination. If a visibly seamless loop is required, choose the tool and rehearse that condition explicitly.

Can it serve as a show backup?

Define a specific manual operation: who opens which file, picture/audio destination, who authorizes the change and expected end behavior. Check the list for unrelated files, shuffle and unintended repeat.

If both files are on one workstation, they depend on the same hardware, operating system and storage. When preparing the backup, consider a failure of those shared dependencies and how long the changeover takes. Installing VLC does not configure automatic switching; prepare and rehearse the procedure with the operator.

Example: an opening video and a holding clip

To review an opening video and a holding clip before delivery, record each defect with its time in the file. Compare the same segment on the planned playback system. If the picture or sound differs, check the file, decoding and presentation before deciding on another conversion.

If the event needs a cue list with precise destinations and transitions, review those requirements with the playback operator. Use VLC to inspect the material and work with the operator to select a tool for preparing and rehearsing the event sequence.

ffprobe 8.1.2: local inspection without conversion

Examples reference official source and documentation at tag n8.1.2; this does not establish the installed or latest version. If ffprobe is already available, record its version first using the following example. These commands are prepared for reading without transcoding or opening a camera or stream.

ffprobe -version

What does the file contain?

Proposed example for an authorized local copy named sample.mp4 in the working folder. Use it as a single line only in a prepared environment. It selects container and all-stream fields without requesting tags or the full filename.

ffprobe -v error -show_entries "format=format_name,duration:stream=index,codec_type,codec_name,width,height,pix_fmt,r_frame_rate,avg_frame_rate,duration,sample_rate,channels,channel_layout" -of json "sample.mp4"

Interpret frame rate, duration and audio

codec_name describes the stream codec; format_name describes the container. width/height and pix_fmt help compare pictures; channels and channel_layout describe each audio stream, not its audible contents. Missing or N/A fields mean unavailable data, not an empty file.

avg_frame_rate is an average; r_frame_rate is a base rate estimated by the library. Keeping 30000/1001 avoids rounding to 30. If they differ, examine frame timing before classifying CFR/VFR: those two numbers are not conclusive proof.

Compare container and stream durations and investigate differences before concluding that a file has failed. Follow the metadata check with playback of the entire file: the report does not verify synchronization, usable transparency or destination compatibility. Keep the file, attach observations with file times and review the report before sharing it.