TyToMpg

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Contents

Overview

TyToMpg (a.k.a. TyToMpeg) is a program written by bcc on the DealDatabase forum. It runs on any PC (Windows, Linux, Macintosh) and converts the TY files extracted from a TiVo to standard MPEG files (that can then be edited/converted to another format). TyToMpg converts from TY/TY+/TMF to mpeg2 program streams in a single step. In other words, it combines the TY demuxing operation with a loss-less re-multiplex operation.


Details

Inside it uses the mature hdemux code for demuxing, and a new purpose-built muxer on the muxing side. For multiplexing, the timestamps from the original TY stream are preserved instead of trying to regenerate them, as was required with hdemux. This has the following benefits:

  • Preserving a/v sync regardless of errors in the audio or video streams. For example, the current tivo bug that plagues much of the FOX OTA broadcasts with audio dropouts does not phase tytompg.
  • tytompg's ability to pass-thru video with varying frame rates (these have historically been a deal-breaker for using the mplex muxer).
  • mpeg2 editors such as videoredo work with tytompg a lot better than hdemux+ffmpeg, as tytompg includes timestamps at all video I frame boundaries (so long as the original recording included them), whereas ffmpeg would often leave out some of these timestamps.


Requirements

  • Any Series 1 or Series 2 TiVo
  • TiVo must be modified and recorded show Encryption must be disabled
  • Shows must be extracted from the TiVo to PC, using a program on the TiVo such as [mfs_ftp]


Download and Installation

Usage

  • In Windows Explorer, Drag the TY file onto the tytompg.exe file and it will automatically create a *.mpg file with the same name but an *.mpg extension. (Note, this only works starting with version 0.16 and later.)
  • Command line usage: At the command prompt, type:
tytompg <show name>.ty

Command Line Options: Output is to <show>.mpg by default. Some switches: -y Allow overwrite of output file without confirmation, even if it already exists -V Omit video stream from output file -A Omit audio stream from output file -s <number> Skip <number> chunks on input before processing. Note: if input file is a .tmf file, this option will not work correctly -n <number> Process <number> chunks from input


Issues with TyToMpg

  • Because tytompg does not try to re-generate the timestamps, this can cause problems for players and mpeg2 editors that assume that an mpeg2 program stream has no errors and/or is dvd compliant. For example, under Linux, mplayer may be unable to properly recover from audio holes, but xine does so just fine. YMMV.
  • There are no DVD navigation records being generated, so players that are unable to perform trick-play-like operations without them (ie simplistic players like MyHD's) will have trouble. This really should only be a real concern for DVD output, in which case you'll need to post-process the mpeg anyways (to fix other issues including the video GOPs not being DVD compliant).