TiVo

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Introduction

TiVo is a format encapsulating MPEG-2 data.

ty format

The ty format consists of multiple chunks. Each chunk contains multiple records. Each record contains multiplexed MPEG-1 or MPEG-2 audio and video data. The multiplexing is non-standard. It looks like a mixture of a Program Stream and a Transport Stream, but lacks some features. Each ty chunk is padded with zeroes to be exactly 128kB. In addition, large ty files consist of multiple parts, each part is composed the same way and has a size of 512 MB (0x20000000 bytes). The first chunk in each part is the header and starts with 0xf5 0x46 0x7a 0xbd. The bytes 12 - 14 in that chunk gives the total number of chunks in this part (coded as 24 bit big-endian).

tmf format

The tmf format is a tar-file that contains a blob of XML data and up to sixteen .ty files.

TiVo format

This is an encrypted MPEG-2 encapsulation used by TiVo To Go. It uses the Turing Cipher Algorithm and a device specific MAK (Media Access Key).