Provided by: ffmpegfs_2.9-1_amd64 bug

NAME

       ffmpegfs - mounts and transcodes a multitude of formats to one of the target formats on
       the fly

SYNOPSIS

       ffmpegfs [OPTION]... IN_DIR OUT_DIR

DESCRIPTION

       The ffmpegfs(1) command will mount the directory IN_DIR on OUT_DIR. Thereafter, accessing
       OUT_DIR will show the contents of IN_DIR, with all supported media files transparently
       renamed and transcoded to one of the supported target formats upon access.

       Supported output formats:

       ┌───────┬─────────────────────┬────────┬───────────────┐
       │       │                     │        │               │
       │FormatDescriptionAudioVideo         │
       ├───────┼─────────────────────┼────────┼───────────────┤
       │       │                     │        │               │
       │AIFF   │ Audio Interchange   │        │ PCM 16 bit BE │
       │       │ File Format         │        │               │
       ├───────┼─────────────────────┼────────┼───────────────┤
       │       │                     │        │               │
       │ALAC   │ Apple Lossless      │        │ ALAC          │
       │       │ Audio Codec         │        │               │
       ├───────┼─────────────────────┼────────┼───────────────┤
       │       │                     │        │               │
       │FLAC   │ Free Lossless Audio │        │ FLAC          │
       ├───────┼─────────────────────┼────────┼───────────────┤
       │       │                     │        │               │
       │HLS    │ HTTP Live Streaming │ H264   │ AAC           │
       ├───────┼─────────────────────┼────────┼───────────────┤
       │       │                     │        │               │
       │MOV    │ QuickTime File      │ H264   │ AAC           │
       │       │ Format              │        │               │
       ├───────┼─────────────────────┼────────┼───────────────┤
       │       │                     │        │               │
       │MP3    │ MPEG-2 Audio Layer  │        │ MP3           │
       │       │ III                 │        │               │
       ├───────┼─────────────────────┼────────┼───────────────┤
       │       │                     │        │               │
       │MP4    │ MPEG-4              │ H264   │ AAC           │
       ├───────┼─────────────────────┼────────┼───────────────┤
       │       │                     │        │               │
       │OGG    │                     │ Theora │ Vorbis        │
       ├───────┼─────────────────────┼────────┼───────────────┤
       │       │                     │        │               │
       │MKV    │ Matroska            │ H264   │ AAC           │
       ├───────┼─────────────────────┼────────┼───────────────┤
       │       │                     │        │               │
       │Opus   │                     │ Opus   │               │
       ├───────┼─────────────────────┼────────┼───────────────┤
       │       │                     │        │               │
       │ProRes │ Apple ProRes        │ ProRes │ PCM 16 bit LE │
       ├───────┼─────────────────────┼────────┼───────────────┤
       │       │                     │        │               │
       │TS     │ MPEG Transport      │ H264   │ AAC           │
       │       │ Stream              │        │               │
       ├───────┼─────────────────────┼────────┼───────────────┤
       │       │                     │        │               │
       │WAV    │ Waveform Audio File │        │ PCM 16 bit LE │
       │       │ Format              │        │               │
       ├───────┼─────────────────────┼────────┼───────────────┤
       │       │                     │        │               │
       │WebM   │                     │ VP9    │ Opus          │
       ├───────┼─────────────────────┼────────┼───────────────┤
       │       │                     │        │               │
       │BMP    │ Video to frameset   │        │ BMP           │
       ├───────┼─────────────────────┼────────┼───────────────┤
       │       │                     │        │               │
       │JPG    │ Video to frameset   │        │ JPEG          │
       ├───────┼─────────────────────┼────────┼───────────────┤
       │       │                     │        │               │
       │PNG    │ Video to frameset   │        │ PNG           │
       └───────┴─────────────────────┴────────┴───────────────┘

OPTIONS

       Usage: ffmpegfs [OPTION]... IN_DIR OUT_DIR

       Mount IN_DIR on OUT_DIR, converting audio/video files upon access.

   Encoding options
       --desttype=TYPE, -odesttype=TYPE
           Select 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 no 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.

           Default: mp4

       --extensions=LIST, -oextensions=LIST
           Set list of extra file extensions recognised as input files.  LIST can contain one or
           more entries, separated by kommas.

           Example: --extensions=xxx,abc,yxz,aaa

           Take care to select extensions that actually can be converted. Specifying something
           like --extensions=txt would make FFmpegfs attempt to transcode text files, resulting
           in error messages, making these files inaccessible.

           Default: Use default set as defined by FFmpeg.

       --audiocodec=TYPE, -oaudiocodec=TYPE
           Select audio codec.  TYPE depends on the destination format and can currently be:

           ┌────────┬───────────────┐
           │FormatsAudio Codecs  │
           ├────────┼───────────────┤
           │MP4     │ AAC, MP3      │
           ├────────┼───────────────┤
           │WebM    │ OPUS, VORBIS  │
           ├────────┼───────────────┤
           │MOV     │ AAC, AC3, MP3 │
           ├────────┼───────────────┤
           │MKV     │ AAC, AC3, MP3 │
           ├────────┼───────────────┤
           │TS, HLS │ AAC, AC3, MP3 │
           └────────┴───────────────┘
           Other destination formats do not support other codecs than the default.

           Default: The default setting for the destination format, see bold codec name in table

       --videocodec=TYPE, -ovideocodec=TYPE
           Select video codec.  TYPE depends on the destination format and can currently be:

           ┌────────┬──────────────────────────┐
           │FormatsVideo Codecs             │
           ├────────┼──────────────────────────┤
           │MP4     │ H264, H265, MPEG1, MPEG2 │
           ├────────┼──────────────────────────┤
           │WebM    │ VP9, VP8, AV1            │
           ├────────┼──────────────────────────┤
           │MOV     │ H264, H265, MPEG1, MPEG2 │
           ├────────┼──────────────────────────┤
           │MKV     │ H264, H265, MPEG1, MPEG2 │
           ├────────┼──────────────────────────┤
           │TS, HLS │ H264, H265, MPEG1, MPEG2 │
           └────────┴──────────────────────────┘
           Other destination formats do not support other codecs than the default.

           Default: The default setting for the destination format, see bold codec name in table

       --autocopy=OPTION, -oautocopy=OPTION
           Select auto copy option, OPTION can be:

           ┌────────────┬────────────────────────────────┐
           │OFF         │ Never copy streams, transcode  │
           │            │ always.                        │
           ├────────────┼────────────────────────────────┤
           │MATCH       │ Copy stream if target supports │
           │            │ codec.                         │
           ├────────────┼────────────────────────────────┤
           │MATCHLIMIT  │ Same as MATCH, only copy if    │
           │            │ target not larger, transcode   │
           │            │ otherwise.                     │
           ├────────────┼────────────────────────────────┤
           │STRICT      │ Copy stream if codec matches   │
           │            │ desired target, transcode      │
           │            │ otherwise.                     │
           ├────────────┼────────────────────────────────┤
           │STRICTLIMIT │ Same as STRICT, only copy if   │
           │            │ target not larger, transcode   │
           │            │ otherwise.                     │
           └────────────┴────────────────────────────────┘
           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 will be a regular MOV/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.

           Default: OFF

       --recodesame=OPTION, -orecodesame=OPTION
           Select recode to same format option, OPTION can be:

           ┌────┬───────────────────────────────┐
           │NO  │ Never recode to same format.  │
           ├────┼───────────────────────────────┤
           │YES │ Always recode to same format. │
           └────┴───────────────────────────────┘
           Default: NO

       --profile=NAME, -oprofile=NAME
           Set profile for target audience, NAME can be:

           ┌────────┬──────────────────────────┐
           │NONE    │ no profile               │
           ├────────┼──────────────────────────┤
           │FF      │ optimise for Firefox     │
           ├────────┼──────────────────────────┤
           │EDGE    │ optimise for MS Edge and │
           │        │ Internet Explorer > 11   │
           ├────────┼──────────────────────────┤
           │IE      │ optimise for MS Edge and │
           │        │ Internet Explorer ⇐ 11   │
           ├────────┼──────────────────────────┤
           │CHROME  │ Google Chrome            │
           ├────────┼──────────────────────────┤
           │SAFARI  │ Apple Safari             │
           ├────────┼──────────────────────────┤
           │OPERA   │ Opera                    │
           ├────────┼──────────────────────────┤
           │MAXTHON │ Maxthon                  │
           └────────┴──────────────────────────┘
           Note: Applies to MP4 output format only, ignored for all other formats.

           Default: NONE

       --level=NAME, -o level=NAME
           Set level for output if available, NAME can be:

           ┌─────────┬─────────────────┐
           │PROXY    │ Proxy – apco    │
           ├─────────┼─────────────────┤
           │LT       │ LT – apcs       │
           ├─────────┼─────────────────┤
           │STANDARD │ standard – apcn │
           ├─────────┼─────────────────┤
           │HQ       │ HQ - apch       │
           └─────────┴─────────────────┘
           Note: Applies to MP4 output format only, ignored for all other formats.

           Default: HQ

   Audio Options
       --audiobitrate=BITRATE, -o audiobitrate=BITRATE
           Audio encoding bitrate.

           Default: 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.

           BITRATE can be defined as... * n bit/s: # or #bps * n kbit/s: #K or #Kbps * n Mbit/s:
           #M or #Mbps

       --audiosamplerate=SAMPLERATE, -o audiosamplerate=SAMPLERATE
           Limits the output sample rate to SAMPLERATE. If the source file sample rate is more it
           will be downsampled automatically.

           Typical values are 8000, 11025, 22050, 44100, 48000, 96000, 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 ut only 22.05 or 44.1 KHz supported, 22.05 KHz
           will be set).

           Set to 0 to keep source rate.

           Default: 44.1 kHz

           SAMPLERATE can be defined as... * In Hz: # or #Hz * In kHz: #K or #KHz

       --audiochannels=CHANNELS, -o audiochannels=CHANNELS
           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.

           Default: 2 channels (stereo)

       --audiosamplefmt=SAMPLEFMT, -o audiosamplefmt=SAMPLEFMT
           Set 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
           for will be reported as command line error and a list of values printed.

           ┌─────────────────┬─────────────────────────────────┐
           │Container FormatSample Format                   │
           ├─────────────────┼─────────────────────────────────┤
           │AIFF             │ 0, 16, 32                       │
           ├─────────────────┼─────────────────────────────────┤
           │ALAC             │ 0, 16, 24                       │
           ├─────────────────┼─────────────────────────────────┤
           │WAV              │ 0, 8, 16, 32, 64, F16, F32, F64 │
           ├─────────────────┼─────────────────────────────────┤
           │FLAC             │ 0, 16, 24                       │
           └─────────────────┴─────────────────────────────────┘
           Default: 0 (Use same as source or the predefined format of the destination if source
           format is not possible).

   Video Options
       --videobitrate=BITRATE, -o videobitrate=BITRATE
           Video encoding bit rate. Setting this too high or low may cause transcoding to fail.

           Default: 2 Mbit

           mp4: May be specified as 500 to 25000 kbit.

           BITRATE can be defined as... * n bit/s: # or #bps * n kbit/s: #K or #Kbps * n Mbit/s:
           #M or #Mbps

       --videoheight=HEIGHT, -o videoheight=HEIGHT
           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.

           Default: keep source video height

       --videowidth=WIDTH, -o videowidth=WIDTH
           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.

           Default: keep source video width

       --deinterlace, -o deinterlace
           Deinterlace video if necessary while transcoding.

           May need higher bit rate, but will increase picture quality when streaming via HTML5.

           Default: no deinterlace

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

           Should normally be left at default.

           Note: Applies to HLS output format only, ignored for all other formats.

           Default: 10 seconds

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

           Should normally be left at default.

           Note: Applies to HLS output format only, ignored for all other formats.

           Default: 30 seconds

   Hardware Acceleration Options
       --hwaccel_enc=API, -o hwaccel_enc=API
           Select the hardware acceleration API for encoding.

           Default: NONE (no acceleration)

       API
           can be defined as...

           ·   NONE: use software encoder

           ·   VAAPI: Video Acceleration API (VA-API)

           ·   OMX: OpenMAX (Open Media Acceleration)

       --hwaccel_dec_blocked=CODEC[:PROFILE[:PROFILE]], -o
       hwaccel_dec_blocked=CODEC:[:PROFILE[:PROFILE]]
           Block codec and optionally profile from hardware decoding. Option can be repeated to
           block several codecs

           Default: no codecs blocked

       CODEC
           can be defined as...

           ·   H263: H.263

           ·   H264: H.264

           ·   HEVC: H.265 / HEVC

           ·   MPEG2: MPEG-2 video

           ·   MPEG4: MPEG-4 video

           ·   VC1: SMPTE VC-1

           ·   VP8: Google VP9

           ·   VP9: Google VP9

           ·   WMV3: Windows Media Video 9

       PROFILE
           can optionally be added to block a certain profile only.

           Example: VP9:0 blocks Google VP profile 0

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

       --hwaccel_enc_device=DEVICE, -o hwaccel_enc_device=DEVICE
           Select the hardware acceleration device. May be required for VAAPI, especially if more
           the one device is available.

           Note: Applies to VAAPI hardware acceleration only, ignored for all other types.

           Default: empty (use default device)

           Example: /dev/dri/renderD128

       --hwaccel_dec=API, -o hwaccel_dec=API
           Select the hardware acceleration API for decoding.

           Default: NONE (no acceleration)

       API
           can be defined as...

           ·   NONE: use software decoder

           ·   VAAPI: Video Acceleration API (VA-API)

           ·   MMAL: Multimedia Abstraction Layer by Broadcom

       --hwaccel_dec_device=DEVICE, -o hwaccel_dec_device=DEVICE
           Select the hardware acceleration device. May be required for VAAPI, especially if more
           the one device is available.

           Note: Applies to VAAPI hardware acceleration only, ignored for all other types.

           Default: empty (use default device)

           Example: /dev/dri/renderD128

   Album Arts
       --noalbumarts, -o noalbumarts
           Do not copy album arts into output file.

           This will reduce the file size, may be useful when streaming via HTML5 when album arts
           are not used anyway.

           Default: add album arts

   Virtual Script
       --enablescript, -o enablescript
           Add virtual index.php to every directory. It reads scripts/videotag.php from the
           FFmpegfs binary directory.

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

           Default: Do not generate script file

       --scriptfile, -o scriptfile
           Set the name of the virtual script created in each directory.

           Default: index.php

       --scriptsource, -o scriptsource
           Take a different source file.

           Default: scripts/videotag.php

   Cache Options
       --expiry_time=TIME, -o expiry_time=TIME
           Cache entries expire after TIME and will be deleted to save disk space.

           Default: 1 week

       --max_inactive_suspend=TIME, -o max_inactive_suspend=TIME
           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.

           Default: 15 seconds

       --max_inactive_abort=TIME, -o max_inactive_abort=TIME
           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.

           Default: 30 seconds

       --prebuffer_size=SIZE, -o prebuffer_size=SIZE
           Files will be decoded until the buffer contains this much bytes allowing playback to
           start smoothly without lags.

           Set to 0 to disable pre-buffering.

           Default: 100 KB

       --max_cache_size=SIZE, -o max_cache_size=SIZE
           Set the maximum diskspace used by the cache. If the cache would grow beyond this limit
           when a file is transcoded, old entries will be deleted to keep the cache within the
           size limit.

           Default: unlimited

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

           Default: 0 (no minimum space)

       --cachepath=DIR, -o cachepath=DIR
           Sets the disk cache directory to DIR. Will be created if not existing. The user
           running FFmpegfs must have write access to the location.

       --disable_cache, -o disable_cache
           Disable the cache functionality completely.

           Default: enabled

       --cache_maintenance=TIME, -o cache_maintenance=TIME
           Starts cache maintenance in TIME intervals. This will enforce the expery_time,
           max_cache_size and min_diskspace settings. Do not set 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 always one will do the maintenance.

           Default: 1 hour

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

       --clear_cache, -o clear_cache
           Clear cache on start up. All previously transcoded files will be deleted.

           TIME can be defined as... * Seconds: # * Minutes: #m * Hours: #h * Days: #d * Weeks:
           #w

           SIZE can be defined as... * In bytes: # or #B * In KBytes: #K or #KB * In MBytes: #M
           or #MB * In GBytes: #G or #GB * In TBytes: #T or #TB

   Other
       --max_threads=COUNT, -o max_threads=COUNT
           Limit concurrent transcoder threads. Set to 0 for unlimited threads. Recommended
           values are up to 16 times number of CPU cores. Should be left at default.

           Default: 16 times number of detected cpu cores

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

           Default: Ignore errors

       --min_dvd_chapter_duration=SECONDS, -o min_dvd_chapter_duration=SECONDS
           Ignores DVD chapters shorter than SECONDS. Set to 0 to disable. This avoids
           transcoding errors for DVD chapters too short to detect its streams.

           Default: 1 second

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

           Default: on

   Logging
       --log_maxlevel=LEVEL, -o log_maxlevel=LEVEL
           Maximum level of messages to log, either ERROR, WARNING, INFO, DEBUG or TRACE.
           Defaults to INFO, and always set to DEBUG in debug mode.

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

       --log_stderr, -o log_stderr
           Enable outputting logging messages to stderr. Automatically enabled in debug mode.

       --log_syslog, -o log_syslog
           Enable outputting logging messages to syslog.

       --logfile=FILE, -o logfile=FILE
           File to output log messages to. By default, no file will be written.

   General/FUSE options
       -d, -o debug
           Enable debug output. This will result in a large quantity of diagnostic information
           being printed to stderr as the program runs. It implies -f.

       -f
           Run in foreground instead of detaching from the terminal.

       -h, --help
           Print usage information.

       -V, --version
           Output version information.

       -c, --capabilities
           Output FFmpeg capabilities: list on the system available codecs.

       -s
           Force single-threaded operation.

USAGE

       Mount your filesystem like this:

           ffmpegfs [--audiobitrate bitrate] [--videobitrate bitrate] musicdir mountpoint [-o fuse_options]

       For example,

           ffmpegfs --audiobitrate 256K -videobitrate 2000000 /mnt/music /mnt/ffmpegfs -o allow_other,ro

       In recent versions of FUSE and FFmpegfs, the same can be achieved with the following entry
       in /etc/fstab:

           ffmpegfs#/mnt/music /mnt/ffmpegfs fuse allow_other,ro,audiobitrate=256K,videobitrate=2000000 0 0

       Another (more modern) form of this command:

           /mnt/music /mnt/ffmpegfs fuse.ffmpegfs allow_other,ro,audiobitrate=256K,videobitrate=2000000 0 0

       At this point files like /mnt/music/{empty}*.flac and /mnt/music/{empty}*.ogg will show up
       as /mnt/ffmpegfs/{empty}*.mp4.

       Note that the "allow_other" option by default can only be used by root. You must either
       run FFmpegfs as root or better add a "user_allow_other" key to /etc/fuse.conf.

       "allow_other" is required to permit any user access to the mount, by default this is only
       possible for the user who launched FFmpegfs.

HOW IT WORKS

       When a file is opened, the decoder and encoder are initialised and the file metadata is
       read. At this time the final filesize can be determined approximately. This works well for
       MP3, AIFF or WAV output files, but only fair to good for MP4 or WebM because the actual
       size heavily depends on the content encoded.

       As the file is read, it is transcoded into an internal per-file buffer. This buffer
       continues to grow while the file is being read until the whole file is transcoded in
       memory. Once decoded the file is kept in a disk buffer and can be accessed very fast.

       Transcoding is done in an extra thread, so if other processes should access the same file
       they will share the same transcoded data, saving CPU time. If all processes close the file
       before its end, transcoding will continue for some time. If the file is accessed again
       before timeout, transcoding will continue, if not it stops and the chunk created so far
       discarded to save disk space.

       Seeking within a file will cause the file to be transcoded up to the seek point (if not
       already done). This is not usually a problem since most programs will read a file from
       start to finish. Future enhancements may provide true random seeking (but if this is
       feasible is yet unclear due to restrictions to positioning inside compressed streams).

       MP3: ID3 version 2.4 and 1.1 tags are created from the comments in the source file. They
       are located at the start and end of the file respectively.

       MP4: Same applies to meta atoms in MP4 containers.

       MP3 target only: A special optimisation is made so that applications which scan for id3v1
       tags do not have to wait for the whole file to be transcoded before reading the tag. This
       dramatically speeds up such applications.

       WAV: A pro format WAV header will be created with estimates of the WAV file size. This
       header will be replaced when the file is finished. It does not seem necessary, though, as
       most modern players obviously ignore this information and play the file anyway.

ABOUT OUTPUT FORMATS

       A few words to the supported output formats. There is not much to say about the MP3 output
       as these are regular constant bitrate (CBR) MP3 files with no strings attached. They
       should play well in any modern player.

       MP4 files are special, though, as regular MP4s are not quite suited for live streaming.
       Reason being that the start block of an MP4 contains a field with the size of the
       compressed data section. Suffice to say that this field cannot be filled in until the size
       is known, which means compression must be completed first, a file seek done to the
       beginning, and the size atom updated.

       For a continuous live stream, that size will never be known. For our transcoded files one
       would have to wait for the whole file to be recoded to get that value. If that was not
       enough some important pieces of information are located at the end of the file, including
       meta tags with artist, album, etc. Also, there is only one big data block, a fact that
       hampers random seek inside the contents without having the complete data section.

       Subsequently many applications will go to the end of an MP4 to read important information
       before going back to the head of the file and start playing. This will break the whole
       transcode-on-demand idea of FFmpegfs.

       To get around the restriction several extensions have been developed, one of which is
       called "faststart" that relocates the aforementioned meta data from the end to the
       beginning of the MP4. Additionally, the size field can be left empty (0). isml (smooth
       live streaming) is another extension.

       For direct to stream transcoding several new features in MP4 need to be active (ISMV,
       faststart, separate_moof/empty_moov to name them) which are not implemented in older
       versions of FFmpeg (or if available, not working properly).

       By default faststart files will be created with an empty size field so that the file can
       be started to be written out at once instead of encoding it as a whole before this is
       possible. Encoding it completely would mean it would take some time before playback can
       start.

       The data part is divided into chunks of about 1 second length, each with its own header,
       thus it is possible to fill in the size fields early enough.

       As a draw back not all players support the format, or play it with strange side effects.
       VLC plays the file, but updates the time display every few seconds only. When streamed
       over HTML5 video tags, sometimes there will be no total time shown, but that is OK, as
       long as the file plays. Playback cannot be positioned past the current playback position,
       only backwards.

       But that’s the price of starting playback fast.

DEVELOPMENT

       FFmpegfs uses Git for revision control. You can obtain the full repository with:

           git clone https://github.com/nschlia/ffmpegfs.git

       FFmpegfs is written in a little bit of C and mostly C++11. It uses the following
       libraries:

       ·   FUSE

       FFmpeg home pages:

       ·   FFmpeg

FUTURE PLANS

       ·   Create a windows version

FILES

       /usr/local/bin/ffmpegfs, /etc/fstab

AUTHORS

       This fork with FFmpeg support is maintained by Norbert Schlia since 2017.

       Based on work by K. Henriksson (from 2008 to 2017) and the original author David Collett
       (from 2006 to 2008).

       Many thanks to them for the original work!

LICENSE

       This program can be distributed under the terms of the GNU GPL version 3 or later. It can
       be found online or in the COPYING file.

       This file and other documentation files can be distributed under the terms of the GNU Free
       Documentation License 1.3 or later. It can be found online or in the COPYING.DOC file.

FFMPEG LICENSE

       FFmpeg is licensed under the GNU Lesser General Public License (LGPL) version 2.1 or
       later. However, FFmpeg incorporates several optional parts and optimizations that are
       covered by the GNU General Public License (GPL) version 2 or later. If those parts get
       used the GPL applies to all of FFmpeg.

       See https://www.ffmpeg.org/legal.html for details.

COPYRIGHT

       This fork with FFmpeg support copyright (C) 2017-2022 Norbert Schlia.

       Based on work copyright (C) 2006-2008 David Collett, 2008-2013 K. Henriksson.

       Much thanks to them for the original work!

       This is free software: you are free to change and redistribute it under the terms of the
       GNU General Public License (GPL) version 3 or later.

       This manual is copyright (C) 2010-2011 K. Henriksson and (C) 2017-2022 by N. Schlia and
       may be distributed under the GNU Free Documentation License (GFDL) 1.3 or later with no
       invariant sections, or alternatively under the GNU General Public License (GPL) version 3
       or later.