Video Playback

SMS turns a bone-stock PlayStation 2 into a video player. Point it at a movie file on any storage device — a burned disc, a USB stick, an MX4SIO microSD card, the internal HDD, SMB or UDPFS — press one button, and it plays. This page covers every video format SMS understands, how to open a file, the on-screen player controls, how the decoding works under the hood, and how to get the smoothest playback out of the console.

Supported video formats

SMS recognises a video by its container and codec, not merely its extension. The heavy lifting is done by a set of FFmpeg-derived decoders that have been hand-optimised for the PS2's Emotion Engine. The table below lists what plays and the file extensions SMS looks for.

Audio inside a video (the soundtrack) is decoded by the same engine that plays standalone music files, so a movie can carry an MP3, AAC, AC3, or other supported audio track. For the full audio picture — including playlists and standalone music — see Audio & Playlists.

Exact implementation limits

These are hard limits visible in the current source, not estimates:

Hardware-confirmed profiles

The generated repository fixtures were played on a real PS2. Every positive case below played correctly, including seeking/pause/return-to-browser checks, while unsupported modern-codec cases failed as expected.

This table is the real-time confirmed baseline, not the full accepted range. Higher dimensions up to the 1024-pixel-per-axis source limit remain valid inputs but have not been qualified as universally smooth.

Playing a video

Opening a movie is a three-key affair: pick the device, walk into the folder, press play.

Player controls

While a video is playing, the pad drives the player directly:

If the movie has an external subtitle file alongside it, SMS displays it over the picture — see Subtitles for how subtitle files are matched and styled.

How SMS decodes video

SMS earns its "good video on a stock PS2" reputation by splitting the work between the Emotion Engine and a dedicated piece of PS2 hardware — the IPU (Image Processing Unit).

• Decoders derived from FFmpeg. SMS's video and audio decoders started life as parts of the FFmpeg project and were then heavily reworked for the PS2 — moving to a packed image format so the decoder produces macroblocks in the IPU's native layout, and making aggressive use of the scratchpad and DMA. The original author measured roughly a 300% speed-up in video decoding versus stock FFmpeg from these changes.
• The IPU does the colour conversion. Turning decoded frames into a displayable picture (the colour-space conversion, YUV → RGB) is handed to the IPU, which runs it as an interrupt-driven process in parallel with the main CPU still decoding the next frames. Because that step is offloaded, the Emotion Engine is free to spend its cycles decoding — which is exactly why a plain, unmodified PS2 can play good-resolution movies at a good frame rate with no HDD and no extra hardware.

Encoding tips

If you are making files for SMS rather than playing existing ones, a few choices make the difference between flawless playback and a slideshow.

• Start from a tested profile. 640×480 at 30 fps with 1.5 Mbit/s MPEG-4 Part 2 video is confirmed in both AVI/Xvid + MP3 and MP4/mp4v + AAC. Lower dimensions or bitrate provide more headroom.
• Use a supported codec, not just a familiar extension. For MP4, select MPEG-4 Part 2 (mp4v), not the much more common H.264 or H.265 encoders.
• Avoid expensive tools when compatibility matters most. B-frames, QPel and GMC are implemented but add work. The hardware-confirmed fixtures use no B-frames.
• Defragment on slower devices. On a device with limited read throughput, a heavily fragmented file forces the console to seek constantly, which can starve the decoder. Copying the file back onto a freshly-formatted card or drive so it lands contiguously gives the smoothest reads, which helps most on the slowest media.
• Add subtitles as a separate file. SMS reads external subtitle files rather than baked-in subtitles, so keep the subtitle track out of the video and drop the .srt / .sub next to it — details on the Subtitles page.

The exact command used for the confirmed 640×480 MP4 profile is:

ffmpeg -i INPUT.mp4 -c:v mpeg4 -vtag mp4v -b:v 1500k -bf 0 -g 30 \
  -s 640x480 -c:a aac -b:a 128k -ar 48000 -ac 2 \
  -movflags +faststart OUTPUT.mp4

Limitations

SMS is a stock-console player, and a few historic limits come with that. Knowing them up front saves a lot of "why won't this play" head-scratching.

• Codec support is deliberately narrow. There are no H.264, H.265, VP9, AV1 or WMV video decoders.
• Interlaced is supported, but not part of the current fixture baseline. The MPEG-4 decoder contains interlaced field/DCT paths, and MPEG-2 supports frame- and field-encoded interlaced video. The published test profiles above are progressive.
• The source ceiling and the real-time ceiling are different. SMS accepts each dimension through 1024, but no single bitrate or resolution below that is guaranteed for every codec-tool and storage combination.
• Large files remain 32-bit addressed. exFAT removes FAT32's filesystem limit, but the SMS file context still limits an individual file to less than 4 GiB.

Where to next