Video playback troubleshooting

If only one video has a problem, start with the three checks below, then try the steps for the matching symptom.

Check these first

Play a different video on the same device. If it plays normally, the problem is probably specific to the original file.
Play the problem video on another Neo Video device. If it works there, check the first device and its connection.
Play the original file directly on a computer, without Neo Video Server. If the same symptom appears, the source file is probably the cause.

Convert the file to address the problem

Converting the file to a widely supported format may make it playable. Try a video converter such as HandBrake or Shutter Encoder. The examples below use ffmpeg, a command-line video conversion tool.

Disclaimer

ffmpeg is intended for advanced users who are comfortable with command-line tools. Conversion is not guaranteed to fix the problem and may remove audio tracks, subtitles, or metadata. Always keep the original file and proceed at your own risk. Installing and using ffmpeg is outside the scope of Neo Video support; refer to the official ffmpeg website. Run the command from the folder containing the original file, and replace input.mkv or input.mp4 inside the quotation marks with its filename.

Find your symptom

Video plays, but there is no sound

No video quality change

Possible causes

The wrong audio track may be selected, or the selected track may use a format that the device or player cannot decode.

What to do

Open the player's Audio menu and try each available track. If another track works, no change to the file is needed.

If none of the tracks has sound on the affected device, this command converts the first audio track to AAC. It keeps the first video track and all subtitle tracks without re-encoding the video.

ffmpeg -i "input.mkv" -map 0:v:0 -map 0:a:0 -map "0:s?" -c:v copy -c:a aac -b:a 256k -c:s copy "output.mkv"

Playback stutters or drops frames

Video quality may change

Possible causes

The video's bitrate may exceed the available bandwidth, the device may be decoding it in software, or the file may contain damaged timestamps. High-bitrate 4K and 10-bit H.264 often expose these limits, but the symptom alone does not identify the cause.

What to do

Compare direct playback on a computer with playback through the server. If only server playback stutters, try moving the viewing device closer to Wi-Fi or connecting the server computer by Ethernet. If the file stutters on several devices, the file itself is the more likely cause.

If the connection is not the cause, make a broadly compatible H.264/AAC MP4 copy. This re-encodes the video and usually reduces its bitrate.

ffmpeg -i "input.mkv" -map 0:v:0 -map "0:a:0?" -c:v libx264 -pix_fmt yuv420p -preset medium -crf 20 -c:a aac -b:a 192k -movflags +faststart "output.mp4"

An MP4 is slow to start or to seek

No video quality change

Possible causes

The MP4 index may be stored at the end of the file, delaying playback and seeking over a network.

What to do

Play the file directly on a computer. If it starts quickly there but remains slow through the server, the location of the MP4 index may be the cause.

Move the index to the beginning of a new file. This does not re-encode the video; processing time depends on the file size.

ffmpeg -i "input.mp4" -c copy -movflags +faststart "output.mp4"

Some subtitles can't be selected, or vanish over AirPlay

No video quality change

Possible causes

Bitmap subtitles such as PGS and VobSub work only when Neo Video uses its built-in compatibility player. The HLS stream used for Apple TV and AirPlay can carry text subtitles, but not bitmap subtitles.

What to do

Use a text subtitle such as SRT. Give it the same filename as the video, apart from the extension, place it beside the video, and reopen the folder. Converting bitmap subtitles requires OCR software and manual proofreading.

Sound slowly drifts out of sync

No video quality change

Possible causes

The file may contain damaged or inconsistent timestamps. Variable frame rate is valid and is not, by itself, evidence of a problem.

What to do

Close the video, reopen it, and check whether the drift begins at the same place. Then try the file on another device. If it drifts in the same way there, the file's timestamps are probably the cause.

Rebuild the timestamps in a new file without re-encoding. If the new file still drifts, there is no single frame-rate conversion that is safe for every file. Keep the original and diagnose the file separately.

ffmpeg -fflags +genpts -i "input.mp4" -map 0 -c copy "output.mp4"

Comb-like horizontal stripes during motion

Video quality may change

Possible causes

The source may be interlaced, as some broadcast recordings are, and is not being deinterlaced correctly.

What to do

Play the file directly on a computer and on another device. If the same stripes appear during motion, the source is probably interlaced.

Convert the video to progressive scan while preserving the source field rate. This re-encodes the video, so compare the result with the original before replacing the file.

ffmpeg -i "input.mkv" -map 0:v:0 -map "0:a?" -vf bwdif=mode=send_field -c:v libx264 -preset slow -crf 18 -c:a copy "output.mkv"

Other issues

The server computer loses free space during playback

Possible causes

When a device cannot play a video as it is — an MKV or AVI file, for example — the server creates temporary playback files while it streams. These temporary files are kept separately from your video, in the server's cache, and can grow to about the remaining running time of that video. Playing different videos on several devices at once uses space for each. Videos your device can play as they are need no temporary files.

What to do

Close the video on every device. The temporary files are removed once the last device closes it.

If free space does not come back — after force-quitting the app, for example — wait about 15 minutes. Temporary files that are no longer playing are removed automatically. To reclaim the space right away, quit Neo Video Server and start it again.

When checking free space, look at the drive your computer's system is on, not the drive holding the video. Temporary files are normally created there.

Thumbnails and other files that remain after playback can be removed with Clear cache in the server settings.