The *.m2v files are normally destined to be multiplexed (muxed), which is the process of adding audio data and perhaps other streams such as subtitles, before use. M2Vs are created by demultiplexing (demuxing) an existing MPEG-2, or by converting another video format to MPEG-2. The file extension m2v is mostly found with SFV Host Files.
Sound Blaster VOC files. VOC files are multi-part and contain silence parts, looping, and different sample rates for different chunks. On input, the silence parts are filled out, loops are rejected, and sample data with a new sample rate is rejected. Silence with a different sample rate is generated appropriately. On output, silence is not detected, nor are impossible sample rates. SoX supports reading (but not writing) VOC files with multiple blocks, and files containing μ-law, A-law, and 2/3/4-bit ADPCM samples.