.MPG MPEG Video
.mpg

MPEG Video

MPG (MPEG-1 Program Stream) is the 1993 ISO video format whose last patent expired in 2017 — the only major video codec that became royalty-free by outliving its own patents rather than being designed that way. Its audio sibling from the same 1993 standard is MP3.

Container structure
Pack
PES
ES
VideoAudioLossyMetadata1993

Common questions

How do I convert MPG to MP4?

FileDex converts MPG to MP4 in your browser — drop the file into the converter above. The conversion re-packs the video because MP4 doesn't accept MPG's old video compression. FileDex re-builds the video and audio in modern formats every device plays, then arranges the file so it starts playing while still downloading.

What is an MPG file?

MPG is the MPEG-1 Program Stream — the way audio and video chunks are interleaved into a single file. The Moving Picture Experts Group published it in August 1993 as part of ISO/IEC 11172, alongside its audio sibling MP3. MPG defaults to 352×240 and 1.15 Mbps, both inherited from the 1991 Video CD constraint.

Is .mpg the same as .mpeg?

The .mpg and .mpeg extensions denote the same format. MPG is the DOS-era three-letter version, mpeg the four-letter version. Internally, both can carry MPEG-1 or MPEG-2 video — the disambiguation lives in two bits of the file's first 14 bytes. Every modern player treats both extensions identically.

Why won't my iPhone play MPG?

iOS Safari refuses MPG containers entirely — Apple dropped MPEG-1 support in mainstream iOS years ago. The fix is conversion to MP4 with H.264 video and AAC audio, the universal compatibility target. FileDex does this conversion locally in your browser, no upload.

Why does MPG video look low-quality?

MPG's defaults — 352×240 picture, 1.15 Mbps bitrate — date to a 1991 design constraint: fitting 74 minutes of video on a 700 MB CD-ROM at the original CD-ROM read speed. The numbers were never updated. Modern MPG files from any encoder still default to those values, which is why MPG video looks 1990s even on 2026 hardware.

What makes .MPG special

The only video codec that walked free
MPEG-1 is the only major video codec that became royalty-free by outliving its own patents.
MPG was patent-locked from 1988 to 2017. Twenty-nine years of royalties to the MPEG-LA patent pool — until the last patent quietly expired. Every other royalty-free codec was *designed* royalty-free (WebM in 2010, AV1 in 2018). MPG is the only one that *became* royalty-free by waiting out its own patents.
MP3's rarely-named video sibling
MPG and MP3 are siblings — same parent ISO standard, same 1993 publication.
MPG (Part 1, the container) and MP3 (Part 3, the audio compression) were published the same day in August 1993 — same ISO standard, ISO/IEC 11172. The most-used audio format in human history and the rarely-thought-about video format are siblings, designed by the same working group in the same envelope.
74 minutes on a CD-ROM
MPG's defaults trace to a 1991 hardware constraint: 74 minutes on a CD-ROM at 1× speed.
MPEG-1's design constraint was hardware-fixed: fit 74 minutes of video on a single 650 MB CD-ROM at the 1× drive speed of 1991 — 150 KB per second. That yields a target bitrate of 1.15 Mbps. The resolution that fits at acceptable quality is 352×240. Both numbers became the format's permanent defaults.
Every DVD is an MPG grandchild
DVD .vob files use MPG's container — same magic bytes, extended one bit.
Open any DVD's `VTS_01_1.VOB` in a hex viewer. The first four bytes: `00 00 01 BA`. The same pack header that opened a 1995 Video CD. DVD didn't replace MPG's container — it extended it. The 1993 architecture outlived its own codec by 30 years, becoming the foundation for every DVD ever pressed.

Why MPG Looks the Way It Looks: A 1991 Whiteboard

In 1991, an engineer at Philips wrote three numbers on a whiteboard: 74 minutes, 650 megabytes, CD spin rate 1×. The third number was the original CD-ROM's read speed in 1991 — the same rate as audio CDs, 150 kilobytes per second. The first two were the disc's playing-time and capacity ceilings, set by the audio CD specification Sony and Philips had published a decade earlier — and none of the three was negotiable. Divide 650 megabytes by 74 minutes: 150 kilobytes per second. Multiply by eight: 1.15 megabits per second. The resolution that fits in that budget is 352×240 in NTSC, 352×288 in PAL — what the spec called SIF, MPG's standard resolution. Three numbers on a whiteboard became the format's permanent shape. The format wasn't designed to look 1990s — the 1990s laser-disc spin rate designed it. Those numbers held for thirty years. The patents that protected them ran shorter.

Continue reading — full technical deep dive

The Only Video Codec That Walked Free

Sometime in 2017, somewhere in California, a calendar quietly ticked past the last MPEG-1 patent expiration date. No press release. No celebration. A video format that began standards work in 1988 had just become royalty-free, twenty-nine years after the working group's first meeting. From 1988 to 2017, every commercial MPG encoder paid the MPEG-LA patent pool — the company that collected royalties from MPG users until the patents expired. A school district encoding classroom video paid the same pool as a broadcaster encoding the evening news. Then the patents ran out. Every other royalty-free video codec available in 2026 was designed royalty-free from the start: WebM in 2010, AV1 in 2018. MPG is the only one that became royalty-free by outliving its own patents — the only video codec on the entire timeline that walked free instead of being designed free. That single fact is why MPG has a quiet second life in the late 2020s. The Internet Archive's video collection encodes legacy holdings to MPEG-1 specifically because the codec ships license-free in every modern decoder. No royalty paperwork. No per-decoder fee. A 1993 format became, in 2017, the only royalty-free video format with three decades of universal player support. The codec that became free in 2017 had a sibling that became free much earlier — and far more famously.

MP3 Has a Video Sibling Almost Nobody Names

MP3 has a video sibling. Same parent specification, same August 1993 publication, same committee — and almost nobody names it. In August 1993, ISO published ISO/IEC 11172, the 1993 international standard that defined MPG. Three parts in the same envelope, same publication date, same working group. Part 1 was Systems — MPG's container format, the way audio and video chunks are interleaved into a single file. Part 2 was Video — the video compression method MPG uses, defined in the 1993 standard. Part 3 was Audio Layer III. That last part has another name: MP3. The most-used audio format in human history and the rarely-thought-about video format are siblings. Same parent specification. Same August 1993 publication. Same committee — the international working group called the Moving Picture Experts Group, led by an Italian research lab. People who know MP3 don't know MPG is the video sibling. People who know MPG — the few who do — don't know MP3 is the audio sibling. They were one envelope in 1993, published the same day, with the same standard number. MP3 is the part of ISO/IEC 11172 the world remembers. The other part the world remembers — but doesn't realize it's remembering — is on every DVD ever pressed.

Every DVD You Ever Owned Inherits MPG's Container

A DVD spins. The drive reads the file VTS_01_1.VOB. Inside that file at offset zero: 00 00 01 BA — the 4-byte marker that opens every MPG file, like a chapter-start signal. The same pack header that opened a 1995 Video CD — the 1993 movie-on-CD format that drove MPG's design. DVD didn't replace MPG's container; it extended it. The format on a DVD is MPEG-2 Program Stream — DVD's container format, a direct extension of MPG's design. Same pack header at offset zero. Same packet structure. Same byte signals announcing each video and audio packet. The disambiguation between MPG and DVD lives in two bits of the pack header itself: MPEG-1 has the value 01 in those bits, MPEG-2 has 00. Change two bits. Get a DVD. Every DVD pressed since 1996 — every Hollywood release, every wedding video, every PlayStation 2 game cinematic, every karaoke disc — uses the architecture published as part of MPG in August 1993. The 1993 wrapper outlived its own codec by thirty years. The DVD spinning in the drive is, structurally, MPG's grandchild.

.MPG compared to alternatives

.MPG vs .MP4
Modern device compatibility and royalty status
MP4 plays on every modern device — iPhone, Android, Apple TV, smart TVs, every browser. MPG plays only on desktop media players like VLC and mpv; iOS Safari refuses MPG entirely. MPG's one structural advantage is royalty status: every MPEG-1 patent expired by 2017, making MPG the only mainstream video container that's fully royalty-free through natural patent expiration. For shipping projects without licensing fees that matters; for everyday playback, MP4 wins.
 MP4 wins
.MPG vs .VOB
Container generation and intended use
.vob files on a DVD are MPEG-2 Program Stream — DVD's container format, a direct extension of MPG's design. Both share the `00 00 01 BA` pack header at offset zero; the disambiguation lives in two bits of the pack header itself. .vob adds DVD-specific features: higher resolution (720×480 or 720×576 vs MPG's 352×240), multiple audio tracks, multi-program multiplexing, and richer metadata descriptors. Outside a DVD's filesystem, .vob is rarely seen in the wild; MPG remains the format archives and broadcasters actually receive.
 NONE wins
.MPG vs .WEBM
Royalty-free codec generation
Both MPG and WebM are royalty-free, on opposite ends of the timeline. WebM (VP9 / AV1) was designed royalty-free at launch in 2010; MPG became royalty-free in 2017 when the last MPEG-1 patent expired. WebM's compression is roughly four times more efficient than MPG's — same visual quality at a quarter of the bitrate. For new royalty-free encoding, WebM is the modern choice; MPG matters mainly for legacy compatibility and decoding old archives.
 WEBM wins

Technical reference

MIME Type
video/mpeg
Magic Bytes
00 00 01 BA MPEG-1/2 Program Stream pack_start_code at offset 0; high two bits at byte 4 disambiguate MPEG-1 from MPEG-2.
Developer
ISO / Moving Picture Experts Group
Year Introduced
1993
Open Standard
Yes — View specification
00000000000001BA ....

MPEG-1/2 Program Stream pack_start_code at offset 0; high two bits at byte 4 disambiguate MPEG-1 from MPEG-2.

Binary Structure

MPG files are MPEG-1 Program Streams — a multiplex format defined in Part 1 of ISO/IEC 11172, the 1993 international standard the Moving Picture Experts Group published. Every MPG file begins with the same four bytes: `00 00 01 BA` at offset 0 — the pack_start_code that opens the first pack header. Following those four bytes, a 14-byte pack header carries the System Clock Reference (a 33-bit timestamp distributed across nine bytes for synchronization) and the multiplex bit rate. Inside each pack, one or more Packetized Elementary Stream packets follow, each opened by its own 4-byte start code: `00 00 01 E0` through `EF` mark video packets (up to 16 simultaneous video streams), `00 00 01 C0` through `DF` mark audio packets (up to 32 simultaneous audio streams), `00 00 01 BB` opens an optional system header that declares stream IDs and rate bounds, `00 00 01 BD` opens a private stream, and `00 00 01 B9` closes the program. Each PES packet carries chunks of one elementary stream — a video frame's compressed data or an audio frame's compressed data. Multiplexing is time-division: video and audio packets interleave by presentation timestamp, not by physical sector. The disambiguation between MPEG-1 and MPEG-2 lives inside the pack header itself: in MPEG-1 the high two bits at byte 4 are `01`, in MPEG-2 they are `00`. The same Program Stream architecture, with those two bits flipped, became MPEG-2 Program Stream — the format inside every DVD's `.vob` files.

OffsetLengthFieldExampleDescription
0x00 pack_start_code Marks the start of every MPG file's first pack — the 4-byte chapter-start signal.
0x04 marker_bits + version High two bits disambiguate MPEG-1 (01) from MPEG-2 (00). Lower bits carry the System Clock Reference's high portion.
0x05–0x0D SCR + mux_rate (continued) 33-bit System Clock Reference timestamp + 22-bit multiplex bit rate, packed across the next 9 bytes per ISO/IEC 11172-1 § 2.4.3.2.
0x0E+ first PES packet First Packetized Elementary Stream packet. Start code identifies stream type; payload carries one chunk of compressed video or audio.
January 1988ISO/IEC JTC 1/SC 29/WG 11 — the Moving Picture Experts Group — founded under Italian convener Leonardo Chiariglione. Mission: a single international standard for compressed digital video and audio.1990First MPEG-1 video draft circulates inside WG 11. Design constraint locked: a target bitrate of 1.15 Mbps and a SIF resolution of 352×240, derived from the 1× CD-ROM read speed.November 1992MPEG-1 final draft approved at the WG 11 meeting in London.August 1993ISO/IEC 11172 published — Parts 1 (Systems, the .mpg container), 2 (Video, the codec), and 3 (Audio, including Layer III which the world later renamed MP3) all released together.1993Video CD (VCD) launched in Asia by Philips, JVC, Matsushita, and Sony — the first mass-market consumer product built directly on MPG's Program Stream architecture.1994ISO/IEC 13818-1 (MPEG-2 Systems) published — strict superset of MPG's Program Stream. Adds Transport Stream for broadcast and extends Program Stream for DVD; the .vob files on a DVD are this extended Program Stream.2003First wave of MPEG-1 patents begins to expire (20-year term from 1980s filings). The MPEG-LA patent pool's MPG royalty stream begins shrinking.2017Last known MPEG-1 patent expires. MPG becomes the only mainstream video codec to reach fully royalty-free status through natural patent expiration rather than royalty-free design — a quiet milestone with no press release.
Inspect MPG container, codec, and resolution ffmpeg 
ffprobe -v quiet -print_format json -show_streams -show_format input.mpg

Dumps every stream's codec, resolution, frame rate, audio sample rate, and container metadata as structured JSON. The `codec_name` field disambiguates MPEG-1 PS from MPEG-2 PS — the answer determines whether MP4 conversion is a remux into MKV (lossless) or a full transcode (re-encode required for MP4).

Stream copy MPG into MKV (lossless, instant) ffmpeg 
ffmpeg -i input.mpg -c:v copy -c:a copy -y output.mkv

Copies the video and audio streams bit-for-bit into an MKV container without re-encoding. MKV is the only mainstream modern container that natively holds MPEG-1 video — V_MPEG1 is a first-class Matroska codec. Finishes in seconds, fully lossless. Use this when archiving without quality loss.

Convert MPG to MP4 with H.264 + AAC + faststart ffmpeg 
ffmpeg -i input.mpg -c:v libx264 -c:a aac -movflags +faststart -y output.mp4

Re-encodes the video to H.264 (the video compression method MP4 uses) and audio to AAC inside an MP4 container — the universal compatibility target for iOS, Apple TV, smart TVs, and HTML5 video. The `+faststart` flag moves the MP4 index to the file head so the file plays while still downloading. Re-encoding is required because MP4 cannot natively store MPEG-1 video.

MPG → MP4 transcode near-lossless MP4 plays on every modern device — iPhone, Apple TV, smart TVs, browsers. The conversion is slower than a copy because MP4 cannot hold MPG's video — FileDex re-builds it as H.264 and the audio as AAC, then moves the index to the front for instant playback.
MPG → MKV remux lossless MKV is the only mainstream modern container that natively holds MPEG-1 video without re-compression. FileDex copies the video and audio streams bit-for-bit into an MKV container — fast, lossless, finishes in seconds. Use this when archiving MPG without quality loss; use MP4 when device compatibility matters.
MPG → MOV transcode near-lossless QuickTime / MOV does not natively play MPEG-1 video on modern Apple systems. FileDex re-compresses the video to H.264 and audio to AAC inside a MOV container — the result plays in QuickTime Player and on iOS, Apple TV, and Final Cut import workflows.
MPG → WEBM transcode lossy WebM is the modern royalty-free target. FileDex re-compresses the video to VP9 — roughly four times more efficient than MPEG-1 at the same visual quality — and audio to Opus. Use this when shipping royalty-free video to modern browsers without legacy patent concerns.
MPG → MP3 transcode near-lossless Extracts the audio track from the MPG and re-encodes it as MP3 — the audio sibling format published in the same 1993 ISO standard. Useful for pulling commentary, music, or speech out of an old MPG recording when only the audio matters.
MPG → GIF transcode lossy Extracts a short clip from the MPG as an animated GIF — useful for short-form sharing where the destination platform refuses video. Quality drops sharply because GIF caps at 256 colors per frame and lacks real motion compression; keep clips under 10 seconds for sensible file sizes.
MEDIUM

Attack Vectors

  • Demuxer parsing bugs in older FFmpeg / libavformat — multiple CVEs in the MPEG Program Stream demuxer over the years (CVE-2017-7866, an out-of-bounds read in `mpegps_read_pes_header`; CVE-2016-10191, a heap overflow in PES parsing). Patched in current FFmpeg, but legacy media players that bundle older FFmpeg / MPlayer / libmpeg2 remain exposed.
  • MPEG-1 video decoder bugs — historical exploits in libmpeg2 (Michel Lespinasse's reference decoder, 2000s era) and in FFmpeg's libavcodec/mpeg12dec.c for crafted MPEG-1 video sequences; out-of-bounds writes in motion-vector decoding. Patched in modern FFmpeg; legacy systems vulnerable.
  • PES timestamp parsing edge cases — historically a source of denial-of-service crashes in media players when System Clock Reference timestamps are crafted out of valid range. Not a code-execution vector; service availability only. Documented in VLC and MPlayer changelogs across 2008–2018.
  • Codec auto-installation prompts on legacy Windows — older Windows Media Player versions historically prompted to install missing codec packs from external sources when encountering unfamiliar MPEG variants. Mostly theoretical post-2018, but documented as a vector on pre-Windows 10 systems.

Mitigation: FileDex processes MPG files entirely in-browser via FFmpeg WebAssembly. The WASM sandbox confines any demuxer or decoder exploit to the browser's isolated WASM memory — no host-system code execution, no DLL loading, no native codec invocation, no codec auto-installation prompts. Legacy libmpeg2 and pre-patch libavformat exploit vectors are bypassed entirely; FileDex tracks FFmpeg upstream releases and uses only the bundled software decoders.

FFmpeg library
Read, write, and transcode every MPG variant (MPEG-1 Program Stream, MPEG-2 Program Stream) via libavformat's mpeg.c demuxer and mpegenc.c muxer. The reference implementation; most other software MPG support ultimately wraps libavformat.
Universal MPG player. Handles MPEG-1 PS, MPEG-2 PS, and elementary streams. Last major release VLC 3.0.21 (June 2024); 4.0 in active development.
HandBrake tool
GUI MPG converter. Reads MPG, writes MP4 / MKV / WebM with H.264 / H.265 / AV1 / VP9 codec choices. Cross-platform.
Avidemux tool
GUI MPG editor. Lossless cuts and joins at GOP boundaries; the spiritual successor to VirtualDub on Linux and macOS.
mpgtx tool
Purpose-built MPEG-1/2 Program Stream cutting and joining tool. Last release 2008; the format hasn't changed since, so the tool still works for archival workflows.
Linux-native MPG playback and transcoding. Active maintenance through 2024.