Select the destination format. TYPE can currently be:

AIFF, ALAC, BMP, FLAC, HLS, JPG, MOV, MP3, MP4, MKV, OGG, Opus, PNG, ProRes, TS, WAV, WebM.

To stream videos, MP4, TS, HLS, OGG, WEBM, MKV, or MOV/PRORES must be selected.

To use HTTP Live Streaming, set HLS.

When a destination JPG, PNG, or BMP is chosen, all frames of a video source file will be presented in a virtual directory named after the source file. Audio will not be available.

To use the smart transcoding feature, specify a video and audio file type, separated by a "+" sign. For example, --desttype=mov+aiff will convert video files to Apple Quicktime MOV and audio-only files to AIFF.

Defaults to: mp4

Select an audio codec. TYPE depends on the destination format and can currently be:

Other destination formats do not support other codecs than the default.

Defaults to: The destination format’s default setting, as indicated by the first codec name in the list.

Select a video codec. TYPE depends on the destination format and can currently be:

Other destination formats do not support other codecs than the default.

Defaults to: The destination format’s default setting, as indicated by the first codec name in the list.

Select the auto copy option. OPTION can be:

This can speed up transcoding significantly as copying streams uses much less computing power as compared to transcoding.

MATCH copies a stream if the target supports it, e.g., an AAC audio stream will be copied to MPEG, although FFmpeg’s target format is MP3 for this container. H264 would be copied to ProRes, although the result would be a regular MOV or MP4, not a ProRes file.

STRICT would convert AAC to MP3 for MPEG or H264 to ProRes for Prores files to strictly adhere to the output format setting. This will create homogenous results which might prevent problems with picky playback software.

Note: When the --audiocodec or --videocodec option is specified, the STRICT option should be used to ensure that the chosen output codec is used in any scenario. MATCH would enable copy if the output format supports the input codec.

Select recode to the same format option, OPTION can be:

Defaults to: NO

Set profile for target audience, NAME can be:

Note: applies to the MP4 output format only, and is ignored for all other formats.

Defaults to: NONE

Set level for output if available. NAME can be:

Note: applies to the MP4 output format only, and is ignored for all other formats.

Defaults to: HQ

Set the list of file extensions to be encoded. LIST can have one or more entries that are separated by commas. These are the only file extensions that will be transcoded. Can be specified numerous times and will be merged, which is required when specifying them in the fstab because commas cannot be used to separate the extensions. The entries support shell wildcard patterns.

Example: --include_extensions=mp4,wmv to encode MPEG-4 and Windows Media files only.

Defaults to: Encode all supported files.

Set a list of file extensions to exclude from the output. LIST can have one or more entries that are separated by commas. Can be specified numerous times and will be merged, which is required when specifying them in the fstab because commas cannot be used to separate the extensions. The entries support shell wildcard patterns.

Example: --hide_extensions=jpg,png,cue to stop covers and cue sheets from showing up.

Defaults to: Show all files.

Select the audio encoding bitrate.

Defaults to: 128 kbit

Acceptable values for BITRATE:

mp4: 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, 176, 192, 224, 256, 288, 320, 352, 384, 416, and 448 kbps.

mp3: For sampling frequencies of 32, 44.1, and 48 kHz, BITRATE can be among 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, and 320 kbps.

For sampling frequencies of 16, 22.05, and 24 kHz, BITRATE can be among 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, and 160 kbps.

When in doubt, it is recommended to choose a bitrate among 96, 112, 128, 160, 192, 224, 256, and 320 kbps.

This limits the output sample rate to SAMPLERATE. If the source file sample rate is higher, it will be downsampled automatically.

Typical values are 8000, 11025, 22050, 44100, 48000, 96000, and 192000.

If the target codec does not support the selected sample rate, the next matching rate will be chosen (e.g. if 24K is selected but only 22.05 or 44.1 KHz is supported, 22.05 KHz will be set).

Set to 0 to keep the source rate.

Defaults to: 44.1 kHz

This limits the number of output channels to CHANNELS. If the source has more channels, the number will be reduced to this limit.

Typical values are 1, 2 or 6 (e.g., 5.1) channels.

If the target codec does not support the selected number of channels, transcoding may fail.

Set to 0 to keep the number of channels.

Defaults to: 2 channels (stereo)

This sets a sample format. SAMPLEFMT can be:

0 to use the predefined setting; 8, 16, 32, 64 for integer format, F16, F32, F64 for floating point.

Not all formats are supported by all destination types. Selecting an invalid format will be reported as a command line error and a list of values printed.

Defaults to: 0 (Use the same as the source or the predefined format of the destination if the source format is not possible.)

This sets the video encoding bit rate. Setting this too high or too low may cause transcoding to fail.

Defaults to: 2 Mbit

mp4: May be specified as 500 to 25,000 kbps.

This sets the height of the transcoded video.

When the video is rescaled, the aspect ratio is preserved if --width is not set at the same time.

Defaults to: keep source video height

This sets the width of the transcoded video.

When the video is rescaled, the aspect ratio is preserved if --height is not set at the same time.

Defaults to: keep source video width

Deinterlace video if necessary while transcoding.

This may need a higher bit rate, but this will increase picture quality when streaming via HTML5.

Defaults to: "no deinterlace"

Set the duration of one video segment of the HLS stream. This argument is a floating point value, e.g., it can be set to 2.5 for 2500 milliseconds.

Should normally be left as the default.

Note: This applies to the HLS output format only, and is ignored for all other formats.

Defaults to: 10 seconds

If the requested HLS segment is less than min_seek_time seconds away, discard the seek request. The segment will be available very soon anyway, and that makes a re-transcode necessary. Set to 0 to disable.

Should normally be left as the default.

Note: This applies to the HLS output format only, and is ignored for all other formats.

Defaults to: 30 seconds

Select the hardware acceleration API for encoding.

Defaults to: NONE (no acceleration).

Block a codec and, optionally, a profile for hardware decoding. The option can be repeated to block several codecs.

Defaults to: no codecs blocked.

can optionally be added to block a certain profile from the codec only.

Example: VP9:0 blocks Google VP profile 0.

Example: H264:1:33 blocks H.264 profile 1 and 33.

Select the hardware acceleration device. May be required for VAAPI, especially if more than one device is available.

Note: This only applies to VAAPI hardware acceleration; all other types are ignored.

Defaults to: empty (use default device).

Example: /dev/dri/renderD128

Select the hardware acceleration API for decoding.

Defaults to: NONE (no acceleration)

Select the hardware acceleration device. May be required for VAAPI, especially if more than one device is available.

Note: This only applies to VAAPI hardware acceleration; all other types are ignored.

Defaults to: empty (use default device)

Example: /dev/dri/renderD128

Do not copy album art into the output file.

This will reduce the file size and may be useful when streaming via HTML5 when album art is not used anyway.

Defaults to: add album arts

Add a virtual index.php to every directory. It reads scripts/videotag.php from the FFmpegfs binary directory.

This can be very handy for testing video playback. Of course, feel free to replace videotag.php with your own script.

Defaults to: Do not generate script file

Set the name of the virtual script created in each directory.

Defaults to: index.php

Use a different source file.

Defaults to: scripts/videotag.php

Cache entries expire after TIME and will be deleted to save disc space.

Defaults to: 1 week

While being accessed, the file is transcoded to the target format in the background. When the client quits, transcoding will continue until this time out. Transcoding is suspended until it is accessed again, then transcoding will continue.

Defaults to: 15 seconds

While being accessed, the file is transcoded in the background to the target format. When the client quits, transcoding will continue until this time out, then the transcoder thread quits.

Defaults to: 30 seconds

Files will be decoded until the buffer contains the specified playing time, allowing playback to start smoothly without lags. Both options must be met if prebuffer time and prebuffer size are specified.

Set to 0 to disable pre-buffering.

Defaults to: no prebuffer time

Files will be decoded until the specified number of bytes is present in the buffer, allowing playback to start smoothly without lags. Both options must be met if prebuffer size and prebuffer time are specified.

Set to 0 to disable pre-buffering.

Defaults to: 100 KB

Set the maximum diskspace used by the cache. If the cache grows beyond this limit when a file is transcoded, old entries will be deleted to keep the cache within the size limit.

Defaults to: unlimited

Set the required diskspace on the cachepath mount. If the remaining space falls below SIZE when a file is transcoded, old entries will be deleted to keep the diskspace within the limit.

Defaults to: 0 (no minimum space)

Sets the disc cache directory to DIR. If it does not already exist, it will be created. The user running FFmpegfs must have write access to the location.

Defaults to: ${XDG_CACHE_HOME:-~/.cache}/ffmpegfs (as specified in the XDG Base Directory Specification). Falls back to ${HOME:-~/.cache}/ffmpegfs if not defined. If executed with root privileges, "/var/cache/ffmpegfs" will be used.

Disable the cache functionality completely.

Defaults to: enabled

Starts cache maintenance in TIME intervals. This will enforce the expery_time, max_cache_size and min_diskspace settings. Do not set it too low as this can slow down transcoding.

Only one FFmpegfs process will do the maintenance by becoming the master. If that process exits, another will take over, so that one will always do the maintenance.

Defaults to: 1 hour

Prune the cache immediately according to the above settings at application start up.

Defaults to: Do not prune cache

On startup, clear the cache. All previously transcoded files will be deleted.

Limit concurrent transcoder threads. Set to 0 for unlimited threads. Recommended values are up to 16 times the number of CPU cores. Should be left as the default.

Defaults to: 16 times number of detected cpu cores

Decoding errors are normally ignored, leaving bloopers and hiccups in encoded audio or video but still creating a valid file. When this option is set, transcoding will stop with an error.

Defaults to: Ignore errors

This ignores DVD chapters shorter than SECONDS. To disable, set to 0. This avoids transcoding errors for DVD chapters too short to detect its streams.

Defaults to: 1 second

Windows seems to access the files on Samba drives starting at the last 64K segment when the file is opened. Setting --win_smb_fix=1 will ignore these attempts (not decode the file up to this point).

Defaults to: on

Maximum level of messages to log, either ERROR, WARNING, INFO, DEBUG or TRACE. Defaults to INFO and is always set to DEBUG in debug mode.

Note that the other log flags must also be set to enable logging.