Re: Review requested: audio/atrac3 media type registration
On 2/26/08, actech <actech@jp.sony.com> wrote:
Hi Mark,
In ATRAC receiver side, it is required to know sampling frequency, bit-rate and channel configuration in order to switch and initialize the decoder and associated hardware for immediate starting of ATRAC3, ATRAC-X or ATRAC Advanced Lossless decoding.
We think it is the best way to signal above parameters in SDP session with media type registarion procedure.
Hi Jun. I suppose that answers my question about a recipient being able to determine those parameters from the data itself, but I'm still not clear why a parameter is marked as required when it can only have a single value. Is it perhaps because other values may be supported in the future? Some other reason? Mark.
Hi Mark, We think it is very useful that the all of decoding parameters are available before decoding, without any parsing of payload data. For example, if the receiver has only 48000Hz D/A clock, the receiver can activate sampling rate converter before 44100Hz decoding, or send back decoder capability(refusal of 44100Hz streaming) to sender side in SDP offer-answer exchange. In addition, we made a discuss with AVT chair that also ATRAC3 media type registration should have a bit-rate parameter even if it can be only 44100, considering the consistency that ATRAC-X and ATRAC Advanced Lossless media type have bit-rate parameter. Best Regards, Jun
On 2/26/08, actech <actech@jp.sony.com> wrote:
Hi Mark,
In ATRAC receiver side, it is required to know sampling frequency, bit-rate and channel configuration in order to switch and initialize the decoder and associated hardware for immediate starting of ATRAC3, ATRAC-X or ATRAC Advanced Lossless decoding.
We think it is the best way to signal above parameters in SDP session with media type registarion procedure.
Hi Jun. I suppose that answers my question about a recipient being able to determine those parameters from the data itself, but I'm still not clear why a parameter is marked as required when it can only have a single value. Is it perhaps because other values may be supported in the future? Some other reason?
Mark.
On 27 Feb 2008, at 04:43, Mark Baker wrote:
On 2/26/08, actech <actech@jp.sony.com> wrote:
In ATRAC receiver side, it is required to know sampling frequency, bit-rate and channel configuration in order to switch and initialize the decoder and associated hardware for immediate starting of ATRAC3, ATRAC-X or ATRAC Advanced Lossless decoding.
We think it is the best way to signal above parameters in SDP session with media type registarion procedure.
Hi Jun. I suppose that answers my question about a recipient being able to determine those parameters from the data itself, but I'm still not clear why a parameter is marked as required when it can only have a single value. Is it perhaps because other values may be supported in the future? Some other reason?
It's required by SDP signalling, which is the main place this media type will be used, since many other media types support variable rates. -- Colin Perkins http://csperkins.org/
participants (3)
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actech -
Colin Perkins -
Mark Baker