For streaming, the OraStream (and ClassicsOnlineHD*LL" - a new CD- & HD-quality classical music service with more than 70,000 classical music albums, including 1,000 albums in 24-bit audio resolution) sites uses a MPEG Audio standard format known as MPEG-4 SLS (see attached paper). You would note that this codec is also called HD-AAC by its inventors. OraStream works with the Non-Core version (i.e. without the lossy-AAC core) of MPEG 4-SLS.
The OraStream platform utilises the fine-grain, scalable audio layers of this lossless audio format to scale lossless and high-res audio streaming based on the quality of the user's network connection. When a user connects to our servers, the user's network connection is monitored continuously in real-time. When a user's connection is good, every layer of the bitstream is delivered for lossless audio playback. When the connection is poorer, the server removes some layers (via a bitstream truncation process that ensures optimal multi-channel distribution) to match the poorer connection. Network adaptive audio streaming is dynamic, in real-time and transparent to the user. Music streaming scales from 80 kbps to >5,500 kbps (compressed bitrate quality of 24/192 audio) so quality of service is assured in moderately congested 3G and public-WiFi network conditions. In super fast networks, quality of experience can be achieved with full lossless 24-bit audio streams. As MPEG-4 SLS applications include that of audio archival, the format handles PCM audio in resolutions up to 24bit depth/192kHz sampling frequency. Therefore, with a good connection, users can stream 16-bit, 44.1 kHz and any higher resolution up to 24-bit, 192 kHz audio quality on desktop PCs and mobile devices. Beside using different encoding methods, MQA encapsulation is carried out during encoding and MQA files are fixed bit-rate files. The smallest near CD- or CD-quality file (without MQA) requires about 1 Mbps connection to stream (with good QoS experience). The MQA files (of high-res audio recordings) are only about 50%-100% larger (for downloads). Notwithstanding, Meridian claims that MQA files are master-quality-authenticated (by artists, producers, sound engineers) to sound as the original studio recordings are intended or better. 17153 +-------------------------------------------------------------------+ |Filename: AES Paper 120 Convention.pdf | |Download: http://forums.slimdevices.com/attachment.php?attachmentid=17153| +-------------------------------------------------------------------+ ------------------------------------------------------------------------ orastream's Profile: http://forums.slimdevices.com/member.php?userid=63868 View this thread: http://forums.slimdevices.com/showthread.php?t=102914 _______________________________________________ discuss mailing list discuss@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/discuss
