MPG and MPEG to MP4

MPEG is not MPEG-4

MPEG is a family of standards, and the names trip people up. Files ending in .mpg or .mpeg hold MPEG-1 video (1993, the format of Video CDs) or MPEG-2 (DVDs and digital TV). MP4, short for MPEG-4 Part 14, came later and usually carries H.264. People searching for “MPEG4 to MP4” often have one of these older files, or an MP4 that a device still refuses.

So if a file already ends in .mp4, it is MPEG-4 and there is nothing to convert, unless a device wants a different codec inside: an MP4 can hold H.264, HEVC or others, and that inner codec is what devices care about. The MP4 converter page covers that case. Everything below is about the older .mpg and .mpeg files.

Where MPEG files come from

• Video CDs: MPEG-1 at 352 × 240 (352 × 288 in PAL countries), about 1.15 Mbit/s.
• DVD recorders and DVDs: MPEG-2 at 720 × 480 or 720 × 576. A disc's own files are VOBs; see VOB to MP4.
• TV capture cards and set-top recorders, which saved MPEG-2 programs, sometimes as transport streams (TS to MP4).
• Camcorders that recorded MPEG-2 to mini DVDs or a hard disk, before AVCHD.
• Old web and digital camera clips in MPEG-1.

Windows and VLC still play them. Phones, smart TVs, editing apps and upload forms are another matter, which is where MP4 comes in. Not sure which kind you have? Each row in the converter says MPEG-1 or MPEG-2 before you start.

Why the MP4 usually comes out smaller

H.264 needs roughly half the data MPEG-2 does for the same picture, and MPEG-1 is older still. Octoolo takes that into account when it sets the H.264 bit rate: it aims for the detail in your file, not its megabytes, so the MP4 is usually smaller than the MPEG. Picture size and frame rate remain as recorded unless you change them, so a 720 × 576 recording comes out at 720 × 576.

Octoolo does not copy MPEG-1 or MPEG-2 pictures into an MP4, so the picture is always re-encoded; that is what takes the time, and your graphics card handles it if it has a video encoder. The sound is handled on its own: Dolby Digital (AC-3), common on DVD recordings, is copied as it is with As it is, while MPEG audio (MP2) and uncompressed PCM become AAC.

Tidying up recordings

Recordings from TV and DVD recorders often run on before and after the part you wanted, or come in several pieces. Convert them first, then open the MP4s in the Video Editor to trim the ends or join the pieces into one video. Your MPEG files stay as they were, so you can always go back to them.

For a big batch of tapes that were digitized to MPEG-2 years ago, point Save in at A folder I choose… so the MP4s gather in one place, and let the queue run: one file is encoded at a time, and the rest wait their turn without you doing anything. Tape captures keep the look of their source, noise, soft color and all: the conversion changes the format, not the footage.