M2TS to SPX Converter

M2TS (MPEG-2 Transport Stream) is a container format used primarily for multiplexing audio, video, and other data on Blu-ray Disc media. The format is specified as part of the Blu-ray Disc Audio-Video (BDAV) standard developed by the Blu-ray Disc Association, with commercial Blu-ray products launching in 2006. M2TS files wrap content in MPEG-2 transport stream packets with an additional 4-byte timestamp header prepended to each 188-byte packet, resulting in 192-byte packets that enable more precise timing and error recovery during optical disc playback. This extended packet structure helps maintain synchronization when dealing with the variable read speeds inherent to disc-based media. M2TS supports the major Blu-ray video codecs including H.264/AVC, MPEG-2, and VC-1, alongside audio formats such as Dolby TrueHD, DTS-HD Master Audio, and LPCM for lossless surround sound. The container is also used by AVCHD camcorders for recording high-definition footage, making it common in both consumer disc playback and video production workflows. M2TS files preserve chapter markers, subtitle streams, and interactive menu data within the transport stream. Reliable synchronization mechanisms and support for high-quality codecs make M2TS well-suited for archiving high-definition content where preserving full source quality is essential.

Speex is an open-source audio codec purpose-built for speech compression, developed by Jean-Marc Valin under the Xiph.Org Foundation. First released in October 2002, it targets voice-over-IP, conferencing, and any scenario where spoken word needs to travel efficiently over a network. SPX files wrap Speex-encoded audio inside an Ogg container, pairing the codec's speech optimization with Ogg's streaming capabilities. Three sampling rates are supported — narrowband at 8 kHz, wideband at 16 kHz, and ultra-wideband at 32 kHz — along with variable bitrate encoding that adapts in real time to speech complexity. A standout advantage is its patent-free, BSD-licensed nature, which allowed developers to embed it freely in both commercial and open-source products. Speex also bundles acoustic echo cancellation, noise suppression, and automatic gain control, features that rival codecs typically delegate to external libraries. Although its creators officially recommend Opus as a successor since 2012, Speex remains deployed in legacy VoIP systems, archived recordings, and embedded devices where its lightweight decoder footprint is still valued.