ERF to FLV Converter

ERF to FLV Converter

ERF is Epson RAW Format — the negative written by the Epson R-D1 rangefinder and its two successors, and by nothing else. FLV is Flash Video, Adobe's container from the era when web video meant a browser plug-in. Putting one inside the other is an unusual request, and it is worth knowing exactly what you get: the raw still is developed into ordinary pixels and then held as a short, silent clip. This page documents both formats, the codecs FLV can carry, and the settings that change the output.

ERF Format at a Glance

FLV Format at a Glance

How to Convert ERF to FLV

1. Upload Your ERF Files: Drag and drop your .erf files onto the page or click "+ Add Files". Raw files are large, so the upload is usually the longest part of the job; several frames can be queued at once.
2. Set Merge strategy and Duration: "Merge strategy" is preselected to "Merge images", which places every uploaded photo back to back in one FLV; "Video per image" writes a separate file each. Under "Image Duration", the "Duration" dropdown is preselected to "5 seconds per frame".
3. Choose a Video Codec, Background Color and Quality Preset (Optional): "Video Codec" is preselected to FLV — that is Sorenson Spark — and also offers H.264, Flash Video and Flash Video (v2). "Background Color" is preselected to White and fills letterbox bars; "Quality Preset" sits on "Very High (Recommended)", with Constant Quality and Constraint Quality as alternatives.
4. Convert and Download: Click "Convert" and download the FLV. Files upload over an encrypted connection, are processed on our servers, and are deleted automatically after a few hours. No sign-up, no watermark.

What the Conversion Actually Produces

From one ERF you get a silent clip that shows a single rendered photograph for the duration you set — no pan, no zoom, no transition, no soundtrack, because a still image has neither motion nor audio to carry. Image-sourced clips are encoded at one frame per second with B-frames disabled, so a five-second hold is five identical frames. Before encoding, the source is re-rendered to a clean PNG and clamped to 4096 pixels on the long edge; raw camera formats such as ERF fall through to an ImageMagick decode when the faster path declines them. If you upload several photos with "Merge images" selected, they appear in upload order with hard cuts between them.

The codec choice is the one decision on this page that materially changes the result. Sorenson Spark is the most "authentic" FLV — it is what Flash Player 6 and 7 demanded — but it is an H.263 derivative and the weakest of the four options for a detailed photograph. H.264 gives a much better result at the same size and has been legal inside FLV since December 2007. The two Flash Screen Video codecs are block-based screen-capture codecs, designed for slides and screencasts rather than continuous-tone camera frames, so they are a poor fit here unless something downstream specifically asks for them.

Frequently Asked Questions

Which codec does the FLV output use, and should I change it?

FLV — Sorenson Spark — is preselected, because that is the codec the container is historically associated with and the one legacy Flash tooling expects. If your only requirement is a watchable file that happens to carry the .flv extension, switch "Video Codec" to H.264: Adobe added H.264 to Flash Video in Flash Player 9 Update 3 on 3 December 2007, and it gives far better quality for the same file size than an H.263 derivative. Flash Video and Flash Video (v2) are screen-capture codecs and are not a good match for a photograph. No audio codec is offered, because the source has no audio.

Will my FLV play now that Flash is gone?

Not in a browser. Adobe ended support for Flash Player on 31 December 2020 and began blocking Flash content on 12 January 2021, so an .flv no longer embeds in a web page or runs through the old plug-in. It does still play in standalone software that carries its own decoders — VLC, mpv and ffmpeg all open FLV, including Sorenson Spark, VP6 and H.264 streams. If you need something that plays anywhere in 2026, convert to ERF to MP4 instead.

Why is there no sound, and no audio codec option?

Because an ERF is a photograph. There is no audio anywhere in the source file to carry into the container, so no audio stream is written and the Audio Codec control is not rendered for image-to-video conversions. If the clip needs music or narration, add it afterwards in a video editor.

Is ERF compressed, and why are the files so large?

ERF is not compressed, contrary to what several converter sites claim. darktable's RawSpeed reads it with its uncompressed decompressor — 12-bit samples, MSB-first, with a control byte interleaved roughly every ten pixels. That is the whole explanation for the file size: 6.1 million photosites at 12 bits each is about 9 MB of pixel data by simple arithmetic, before metadata and the embedded preview are counted. A 6-megapixel camera writing 10 MB files looks strange until you know the pixels are stored raw.

How much quality do I lose going from a 12-bit raw to FLV?

A lot, and every stage contributes. Demosaicing the Bayer data bakes in one white balance, exposure and tone curve, ending the raw latitude. The frame is then scaled to a video resolution, which for a 6.1-megapixel photograph usually means downscaling. Finally the codec compresses lossily — noticeably so with Sorenson Spark, which was designed for low-bitrate web video in the early 2000s. Keep the original .erf and treat the FLV as a disposable delivery file.

Can I turn several ERF photos into one FLV slideshow?

Yes. Upload them in the order you want, leave "Merge strategy" on "Merge images", and set "Duration" to how long each photo should hold. The result is a single FLV with each rendered frame shown in turn. There are no transitions or cross-fades — just hard cuts — and the whole clip is silent.

What opened ERF files originally, and what opens them now?

Epson never shipped a widely used raw developer of its own, so R-D1 owners have always leaned on third-party decoders. LibRaw's supported-camera list covers the R-D1, R-D1s and R-D1x, ExifTool reads and writes the format's metadata, and the Epson-specific white-balance tag inside the file is what decoders read to derive the correct colour coefficients. So the originals are readable — they are just not viewable without a raw-aware application, which is the whole reason to render a copy.

Should I be converting to FLV at all?

Almost certainly not, and it is worth saying plainly. This pairing mismatches three ways: a raw still becomes a video, an archival photograph becomes a lossy consumer clip, and the target container's host platform has been dead since the end of 2020. If you want to look at, print or share the picture, use ERF to JPG. If you genuinely need a clip, use ERF to MP4. Choose FLV only when a legacy Flash-era tool refuses to accept anything else — and see the ERF converter hub for the full list of alternatives. Files are uploaded over an encrypted connection, processed on our servers, and deleted automatically after a few hours in every case.