


tcexport(1)                                           tcexport(1)


NAME
       tcexport - Simple frontend to transcode's encoding subsystem


SYNOPSIS
       tcexport [ -i video_file ] [ -p audio_file ] [ -o output_file ] [ -c
       f1-f2[,f3-f4[,...]]  ] [ -N fmt,fmt ] [ -R n[,video_log[,audio_log]] ]
       [ -P profile[,profile] ] [ -y video_mod,audio_mod,mplex_mod ] [ -w
       bitrate[,keyint[,crisp]] ] [ -b bitrate[,vbr[,quality[,mode]]] ] [ -D ]
       [ -d verbosity ] [ -m path ] [ -v ]


COPYRIGHT
       tcexport is Copyright (C) by Francesco Romani


DESCRIPTION
       tcexport was designed as a debug tool for transcode's encoding code: it
       fits in a very limited range of usage cases; however, it can also be
       used independently if you like.
       tcexport encodes and multiplexes a raw YUV4MPEG2/WAV V/A stream using
       given parameters and transcode encoder components. tecexport provides
       direct and complete access to transcode's encoding features and mod-
       ules, but hasn't any of transcode import/extracting/decoding/filtering
       capabilities. Use some other tc* tool if you need those facilities.
       tcexport's options are intentionally made similar, or identical if fea-
       sible, to corresponding transcode's encoding options.


OPTIONS
       -i video_file
              Specify the path of video source.  Only regular files on
              filesystem are supported.  video_file must be a YUV4MPEG2
              stream, nothing else is supported.

       -p audio_file
              Specify the path of audio source.  Only regular files on
              filesystem are supported.  audio_file must be a WAVE stream,
              nothing else is supported.

       -o output_file
              Specify the (base)path of output file. Some multiplexors (es:
              raw multiplexor) uses value of this option as an hint to make
              the final  output file(s) (i.e.  appending different extensions
              for A/V streams).

       -c f1-f2[,f3-f4[, ... ] ]
              encode only frames f1-f2 [and f3-f4 and so on].  Default is to
              encode all available frames.  Use this and you will get statis-
              tics about remaining encoding time.  The f[N] parameters may
              also be timecodes in the HH:MM:SS.FRAME format. Example:
              -c 500-0:5:01,:10:20-1:18:02.1

                     Will encode only from frame 500 to 5 minutes and 1 second



tcexport(1)                9 April 2006                         1





tcexport(1)                                           tcexport(1)


                     and from 10 min, 20 sec to 1 hour, 18 min, 2 sec and one
                     frame.

              Note that tcexport, ad well as transcode, starts counting frames
              at 0 and excludes the last frame specified.  That means that "-c
              0-100" will encoded 100 frames starting at frame 0 up to frame
              99

       -N video_format,audio_format
              Setup the desired encoded video and audio format respectively.
              You must always use this option since there is some encoder mod-
              ules (notably encode_ffmpeg) that support a lot of codecs, and
              tcexport nor modules can automatically choose a sane one not
              have defaults (yet).

       -R n[,video_log[,audio_log]]
              enable multi-pass encoding (0-3) [0,divx4.log,pcm.log].

              0 Constant bitrate (CBR) encoding. [default]
                  The codec tries to achieve constant bitrate output. This
                  means, each encoded frame is mostly the same size. This type
                  of encoding can help in maintaining constant filling of
                  hardware buffer on set top players or smooth streaming over
                  networks. By the way, Constant bitrate is often obtained
                  sacrifying quality during high motion scenes.

              1 Variable bitrate encoding: First pass.
                  In this mode, the codec analyses the complete sequence in
                  order to collect data that can improve the distribution of
                  bits in a second VBR pass. The collected data is written to
                  second sub argument (default: divx4.log). This data is codec
                  dependant and cannot be used across codecs. It is strongly
                  advised to use the same codec settings for the VBR analysis
                  pass and the VBR encoding pass if you want predictable
                  results.

                  The video output of the first pass is not of much use and
                  can grow very large.  It's a good idea to not save the video
                  output to a file but directly to /dev/null.  Usually the
                  bitrate is ignored during first pass.  Disabling audio
                  export makes sense too, so use -y.

              2 Variable bitrate encoding: Second pass.
                  The first pass allowed the codec collecting data about the
                  complete sequence.  During the second pass, the codec will
                  use that data in order to find an efficient bit distribution
                  that respects both the desired bitrate and the natural
                  bitrate curve shape. This ensures a good compromise between
                  quality and desired bitrate.

              3 Constant quantizer encoding.
                  The quantizer is the "compression level" of the picture. The
                  lower the quantizer is, the higher is the quality of the
                  picture. This mode can help in making sure the sequence is



tcexport(1)                9 April 2006                         2





tcexport(1)                                           tcexport(1)


                  encoded at constant quality, but no prediction can be made
                  on the final bitrate. When using this mode, the -w option
                  changes its meaning, it now takes the quantizer ranging from
                  1 to 31. Note that constant quantizer encoding is not sup-
                  ported with some codecs (notably mpeg1/2/4 with -y ffmpeg).

       -P profile[,profile]
              select export profile(s) to load. An export profile it's just a
              different, already tuned, set of basic values for tcexport's
              options. Even if isn't recomended, an user can always overwrite
              profile settings just using standard options.  export profiles
              are stackable, just requesting to load multiple profiles sepa-
              rated by commas; if some options are set by more than one pro-
              file, the last profile determine their value.

       -y video_mod,audio_mod,mplex_mod
              Select export modules: video and audio encoders, and multiplexor
              module.  You always must select both the encoders and multi-
              plexor, there isn't implicit modules. The only exception to this
              rule is if this option isn't used at all: in this case tcexport
              will use null modules.

       -w bitrate[,keyint[,crisp]]
              encoder bitrate[,keyframes[,crispness]] [(6000 for MPEG 1/2,
              1800 for others),250,100].

       -b bitrate[,vbr[,quality[,mode]]]
              audio encoder bitrate kBits/s[,vbr[,quality[,mode]]] [128,0,5,0]

       -D     Select dry run mode: tcexport will probe stream, load selected
              modules then exit, without doing anything else.

       -d verbosity
              Select the verbosity of program, support code and modules. See
              transcode's manpage to see supported verbosity levels. Please
              note that higher verbosity levels include lower ones, so if You
              select i.e. TC_DEBUG level you will get TC_DEBUG messages and
              TC_INFO messages. Please also note that high verbosity levels
              will output a lot of messages.

       -m path
              Look in Path instead of the compiled-in module path for a mod-
              ule.

       -v     Print version information and exit.


RETURN VALUES
       tcexport uses following return values:
        0  successfull
        1  bad parameter or command line option
        2  error while reading/writing from/to a file
        3  requested an inexistent (or unreadable) module
        4  a module raised an internal error



tcexport(1)                9 April 2006                         3





tcexport(1)                                           tcexport(1)


        5  error while probing input file(s). Make sure they are of right for-
       mat.
       64  internal error. Please provide a report of what's happened on
       transcode-devel mailing list



AUTHORS
       tcexport was written by Francesco Romani
       <fromani@gmail.com> with contributions from the Transcode Team and many
       others.  See AUTHORS for details.


SEE ALSO
       tccat(1), tcdecode(1), tcdemux(1), tcextract(1), tcprobe(1),
       transcode(1) tcmodinfo(1)









































tcexport(1)                9 April 2006                         4


