Does the M4R to MP3 converter keep ID3 / metadata tags?
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Yes — title, artist, album, year, track number, and album art are read from the M4R container and written into the MP3 container where the format supports tags. All common targets (MP3, AAC, FLAC, OGG) handle tags fine; raw WAV does not.
我可以批量转换成 M4R 成百上千个文件 MP3 吗?
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Yes — drop a folder of M4R files in and we process them in parallel. Premium has more parallel workers and no per-file size cap, so a 500-file batch finishes in minutes rather than tens of minutes.
Yes — uploaded M4R files are processed in isolated workers and deleted within minutes. We never play back, store long-term, or share the audio content. The full retention window is in /privacy/.
转换一个 1小时 M4R 到 MP3 需要多久?
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Same-codec re-mux: 10 to 30 seconds. Re-encode to a different codec: typically 10 to 20% of source duration, so a 1-hour M4R → MP3 finishes in 6 to 12 minutes. Batch jobs parallelize across workers for further speedups.
Why is the MP3 louder or quieter than the M4R source?
If the M4R download is unprotected (no DRM), yes. DRM-encrypted streams (Spotify, Apple Music tracks) are encrypted at the bit level and we cannot process them. Bandcamp, SoundCloud downloads, personal recordings, and podcast files convert cleanly.