MPG to FLAC Converter

MPG Audio vs FLAC — What a Lossless Target Can and Cannot Do

An MPG file is an MPEG program stream: the Video CD, DVD and broadcast-capture container whose soundtrack is almost always MPEG-1 Audio Layer II (MP2), Dolby AC-3, or occasionally LPCM. FLAC is lossless, which means it reproduces every sample you hand it exactly. The two facts together give an honest answer to the usual question — extracting to FLAC gives you a permanent, edit-safe, generation-proof copy of the soundtrack, but it cannot restore anything the original MP2 or AC-3 encode already discarded. If the source was LPCM on a DVD, the FLAC holds a bit-exact copy of those samples; otherwise it holds a lossless copy of already-lossy audio, which is still the right choice for editing and archiving.

Side-by-side Comparison

Which Audio Track Gets Extracted

This matters more on DVD-sourced MPG files than anywhere else, because a DVD program stream frequently carries more than one soundtrack — a 5.1 AC-3 mix, a stereo AC-3 or MP2 mix, sometimes a commentary track.

We checked this page's own option set: there is no track selector here, so the choice falls to the decoder's default rule. It picks the audio stream with the most channels, and if two streams tie it takes the one with the lowest index. On a typical DVD rip that means the 5.1 surround track wins over the stereo mix, even when the stereo mix is the one listed first. If your FLAC arrives with six channels and you expected two, that is why — and setting Audio Channel to Stereo downmixes it in the same pass. If you need a specific alternate track rather than the widest one, demux it in a desktop tool before uploading.

How to Convert MPG to FLAC

1. Upload Your MPG File: Drag and drop your .mpg or .mpeg file, or click "Add Files". Several files can be queued and each is processed with the same settings.
2. Set the Compression Level: The Compression level slider runs 1 to 12 and starts at 12. It controls how hard the encoder searches for a smaller file, not how the result sounds — every level decodes back to identical audio.
3. Choose Audio Channel, Sample Rate, or a Trim (Optional): Audio Channel offers Original, Mono or Stereo; Audio Sample Rate offers Original, 8000, 12000, 16000, 24000, 44100 or 48000 Hz. Leave both on Original for a faithful transfer. Trim keeps only a start time and duration.
4. Convert and Download: Click Convert and download the FLAC. Files upload over an encrypted connection, are processed on our servers, and are deleted automatically after a few hours — no sign-up, no watermark, never shared.

What to Set for Each Goal

Frequently Asked Questions

Does converting MPG to FLAC improve the audio quality?

No, and no format can. MP2 and AC-3 both throw away detail permanently at record time; FLAC preserves whatever it is handed, which by then is the already-reduced signal. What you gain is that the audio stops degrading: you can cut, normalise, re-save and convert a FLAC as many times as you like without ever adding another generation of lossy damage. The ceiling was set by the original encode, not by FLAC.

Why is the FLAC bigger than the MPG's audio track?

Because a lossy stream is a compact description of the sound while FLAC stores the decoded waveform, compressed only by patterns it can predict losslessly. A 224 kbps MP2 track becomes a FLAC in the region of several hundred kilobits per second, several times larger. Lossy sources also compress worse than clean recordings, because the encoder's own artefacts break up the patterns FLAC relies on. If a small file matters more than losslessness, MPG to MP3 is the better tool.

What does the Compression level slider actually change?

Encoder effort and encode time — never the audio. FLAC is lossless at 1 and at 12 alike, and both decode to bit-identical samples. Level 12 asks the encoder to search harder for efficient predictors, which takes longer and typically saves a few percent of file size over the low levels. If you are pushing a large batch through and size is not critical, dropping to 3 or 5 is the sensible trade.

My FLAC came out with six channels. How do I get a stereo file?

Set Audio Channel to Stereo before converting. The six channels come from the extraction rule described above picking the widest track on the disc — usually the 5.1 AC-3 mix. Choosing Stereo downmixes it in the same pass, so you do not need a second conversion. Choosing Mono collapses it further, which is useful for dialogue references but discards the stereo image.

Should I extract to FLAC or WAV?

Both are lossless, so they sound identical; the difference is size and metadata. FLAC compresses the same samples into a smaller file and carries tags natively, which makes it the better archive format. WAV is uncompressed and slightly more universal in older audio software and hardware samplers. If a tool in your chain refuses FLAC, MPG to WAV gives you the uncompressed equivalent from the same source.

Does the output keep the video, or any of the timing metadata?

Only the audio. The video stream is discarded entirely, which is why the FLAC is a small fraction of the MPG's size even though it is lossless — picture data is the bulk of a video file. Chapter marks, subtitle streams and the program-stream timing structure do not survive either, since FLAC has no place to store them. If you need the picture, convert to a video target such as MPG to MP4 instead.

Is FLAC free to use, or are there licensing issues?

FLAC is royalty-free with an open reference implementation, and since December 2024 it has been a formally published IETF Proposed Standard, RFC 9639. That combination — an open specification plus a stable, widely implemented decoder — is exactly why libraries, archives and music services standardised on it for long-term storage rather than on a proprietary lossless format.

Can I trim the audio without re-converting the whole video?

The Trim control on this page takes a start time and a duration and encodes only that window, which is the fastest route because the rest of the file never reaches the encoder. If you would rather cut afterwards, Audio Cutter accepts FLAC directly. Note that Audio Cutter only takes audio files — to cut the MPG itself before conversion, use Video Cutter, which accepts .mpg among its input formats.