Convert FLV to AAC: Free Online Converter
Convert Flash Video to Advanced Audio Coding online for free. Fast, secure video conversion with no watermarks or registration.
FLVに対応
アップロードすることで、これらのファイルの権利を有していること、および利用規約に同意することを確認したものとみなされます。
変換設定: ファイルを追加すると調整できます
安全な転送
HTTPS暗号化アップロード
プライバシー優先
ゲストのファイルは約2時間で自動削除
登録不要
すぐに変換を開始
どこでも動作
あらゆるブラウザ、あらゆるデバイス
FLV から AAC への設定
- エンジン
- メディア
- 設定
- 調整できる設定: 12
- Trim Start
- Trim End
- Volume
- Fade In
- Fade Out
- Bitrate
- Sample Rate
- Channels
- Normalize Volume
- Audio Channels
- Reverse Audio
- Strip Metadata
変換方法
アップロードエリアにドラッグするか、クリックして選択し、.flvファイルをアップロードしてください。
必要に応じて出力設定を調整してください。デフォルト設定ではオリジナルの品質を維持します。
「変換」をクリックし、準備ができたら.aacファイルをダウンロードしてください。
FLVからAACへの変換について
FLV files from the Flash Video era frequently contain audio encoded as MP3 at 44.1 kHz or AAC-LC within Adobe's proprietary container. AAC (Advanced Audio Coding) is the successor to MP3, delivering superior sound quality at equivalent bitrates thanks to its modified discrete cosine transform and temporal noise shaping. Converting FLV to AAC extracts the audio layer and outputs it in a widely compatible format recognized by iOS, Android, iTunes, and every major streaming platform.
FLVをAACに変換する理由
You may have FLV recordings — lectures, music performances, podcasts — where only the audio matters. Extracting to AAC gives you a compact, high-fidelity audio file without the video overhead. AAC at 128 kbps matches or exceeds MP3 at 192 kbps in perceptual listening tests. Since Apple adopted AAC as the default iTunes format in 2003, compatibility is universal across modern devices.
主な活用例
- Extracting lecture audio from FLV screen recordings downloaded from early e-learning platforms
- Ripping music performances from Flash-based concert streams for personal listening playlists
- Creating podcast episodes from FLV interview recordings by extracting clean AAC audio
- Saving storage space by stripping the video track from FLV files where only the dialogue matters
- Preparing audio clips from FLV sources for use in mobile apps or iOS ringtone creation
仕組み
FFmpeg demuxes the FLV container, isolates the audio elementary stream, and either copies the AAC bitstream directly (when the FLV already contains AAC-LC audio) or transcodes MP3/Nellymoser/Speex audio to AAC-LC using the libfdk_aac or native aac encoder. The output is wrapped in an ADTS or MP4 container with .aac extension. Sample rates up to 96 kHz and channel counts up to 7.1 surround are supported.
品質とパフォーマンス
If the source FLV contains AAC audio, conversion is lossless — the bitstream is copied without re-encoding. If the source uses MP3, transcoding from one lossy codec to another introduces a small generation loss. Using a higher output bitrate (192-256 kbps) minimizes audible degradation. The resulting AAC file will typically sound transparent to the original at 128+ kbps.
デバイス互換性
| Device | FLV | AAC |
|---|---|---|
| Windows PC | Partial | Partial |
| macOS | Partial | Native |
| iPhone/iPad | Partial | Native |
| Android | Partial | Partial |
| Linux | Partial | Partial |
| Web Browser | No | No |
プラットフォーム別の推奨設定
YouTube
Resolution: 1920x1080
Bitrate: 8-12 Mbps
H.264 recommended for fast processing
Resolution: 1080x1080
Bitrate: 3.5 Mbps
Square or 9:16 for Reels
TikTok
Resolution: 1080x1920
Bitrate: 4 Mbps
9:16 vertical, under 60s ideal
Twitter/X
Resolution: 1280x720
Bitrate: 5 Mbps
Under 140s, 512MB max
Resolution: 960x540
Bitrate: 2 Mbps
16MB limit for standard, 64MB for document
Discord
Resolution: 1280x720
Bitrate: 4 Mbps
8MB free, 50MB Nitro
最良の結果を得るためのヒント
- 1Check if the FLV already contains AAC audio — if so, use stream copy mode to get a lossless extraction with zero quality loss
- 2For music, set the output to AAC-LC at 256 kbps VBR for the best balance of quality and file size
- 3Use mono output for speech-only content like lectures to halve the file size with no perceptual quality difference
- 4If you need to edit the audio afterward, extract at the highest quality possible and compress later after editing
- 5Tag your AAC files with proper metadata (title, artist, album) after extraction for better library organization
関連する変換
Extracting AAC audio from FLV files rescues valuable audio content trapped in an obsolete video container. Whether you are archiving lectures or building a music library, the AAC output delivers excellent quality with universal device support.
FLVとAACの比較
| 特徴 | FLV | AAC |
|---|---|---|
| 正式名称 | Flash Video | Advanced Audio Coding |
| 拡張子 | .flv | .aac |