Step 1: Upload your FLV files using the button above or by drag and drop.
Step 2: Click the 'Convert' button to start the conversion.
Step 3: Download your converted AC3 files.
FLV to AC3 Conversion FAQ
How do I extract audio from a FLV video as AC3?
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Upload your FLV video. PDF.to pulls the audio track out, encodes it to AC3, and gives you a AC3-only download. The video stream is discarded.
Will the audio in the AC3 match the original FLV quality?
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If the source audio is already in a codec compatible with AC3, we stream-copy without re-encoding — bit-identical to the original. Otherwise we re-encode at 192 kbps by default for near-transparent quality.
What bitrate is the AC3 output?
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192 kbps by default. The options panel exposes 96, 128, 192, 256, and 320 kbps — pick higher for music, lower for voice.
Can I extract only part of the FLV as AC3?
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Yes. Use the trim controls on the upload preview to set start and end times before extracting, and only that range becomes AC3.
Does the converter handle FLV files with multiple audio tracks?
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Yes. If your FLV has several language or commentary tracks, you can pick which one(s) to extract as AC3 in the options panel.
Will the AC3 output have the same sample rate as the source?
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Yes by default. We do not resample unless you explicitly request it. 48 kHz is preserved from movie sources, 44.1 kHz from music sources.
Is the FLV to AC3 extraction free?
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Yes for files under 100 MB. PRO supports larger FLV files (5 GB) and parallel batch extraction.
Does PDF.to read or store my FLV content?
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No. The FLV video and the AC3 audio output are deleted within an hour. Conversion runs in an isolated worker.
Can I batch-extract audio from multiple FLV files?
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Yes — drop a folder of FLV videos and you will get a ZIP of AC3 files back, one per source video.
Will the AC3 preserve tags and metadata?
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Title, artist, and album tags are populated from the FLV container metadata when available. You can edit them after extraction with our audio-tag tool.
Does the converter work on streaming video URLs?
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No — PDF.to converts files you upload, not third-party stream URLs. Download the FLV legally first, then upload it for AC3 extraction.
Why is the AC3 file much smaller than the FLV video?
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Because the video stream (typically 90%+ of file size) is discarded. Only the audio track ends up in the AC3, which is why it can drop from gigabytes to a few megabytes.