ASF to OPUS - Convert audio online

Conversion Results:
# Output File Source File Action

Steps:

1. Click "Choose Files" button to select multiple files on your computer. You can also click the dropdown button to choose online file from URL, Google Drive or Dropbox. The source file can also be video format. Video and audio file size can be up to 200M.

2. Set target audio format, bitrate and sample rate. The target audio format can be WAV, WMA, MP3, OGG, AAC, AU, FLAC, M4A, MKA, AIFF, OPUS or RA.

3. Click "Convert Now!" button to start batch conversion. It will automatically retry another server if one failed, please be patient while converting. The output files will be listed in the "Conversion Results" section. Click icon to show file QR code or save file to online storage services such as Google Drive or Dropbox.

ASF vs OPUS:
Name ASF OPUS
Full name Advanced Systems Format Opus Audio Format
File extension .asf .opus
MIME video/x-ms-asf, application/vnd.ms-asf audio/opus
Developed by Microsoft IETF codec working group
Type of format Digital container format Audio file format
Introduction Advanced Systems Format (formerly Advanced Streaming Format, Active Streaming Format) is Microsoft's proprietary digital audio/digital video container format, especially meant for streaming media. ASF is part of the Media Foundation framework. Opus is a lossy audio coding format developed by Xiph and standardized by the IETF, designed to efficiently code speech and general audio in a single format, while remaining low-latency enough for real-time interactive communication and low-complexity enough for low end ARM3 processors.
Technical details The format does not specify how the video or audio should be encoded; it just specifies the structure of the video/audio stream. This is similar to the function performed by the QuickTime, AVI, or Ogg container formats. One of the objectives of ASF was to support playback from digital media servers, HTTP servers, and local storage devices such as hard disk drives. Opus supports constant and variable bitrate encoding from 6 kbit/s to 510 kbit/s, frame sizes from 2.5 ms to 60 ms, and five sampling rates from 8 kHz (with 4 kHz bandwidth) to 48 kHz (with 20 kHz bandwidth, the human hearing range). An Opus stream can support up to 255 audio channels, and it allows channel coupling between channels in groups of two using mid-side coding.
Associated programs Windows Media Player FFmpeg, AIMP, Amarok, cmus, foobar2000, Mpxplay, MusicBee, SMplayer, VLC media player, Winamp
Sample file sample.asf sample.opus
Wikipedia ASF on Wikipedia OPUS on Wikipedia