CODEWITHSUNDEEP
mp3audio-streamingbandwidthaacicecast
STeN
STeN

Reputation: 6268

Bandwidth for audio stream for the mobile client

1/ I would like to know if I am computing (with rough precision) the bandwidth for MP3/AAC audio stream correctly. Parameters of the stream are:

Sample rate: 44100,  
Bitrate: 128bit
Channels: 2,
Stream type: icecast (no metadata)
Codecs used: MP3 or AAC

The raw audio would be: 44100*128*2 = 11289600 bits/sec = 11025 kbit/sec = ~10.8 MBit/sec. I will count with 10:1 compression ratio (which I think can be more or less correct - but please correct me, if I am wrong) then approx. 1 Megabit/sec should be enough.

2/ Is the computation correct? Because this means that for GPRS (~80 kbps), EDGE (~230kbps), UMTS (~384kbps) it does not make sense to even try those streams. If my computation is correct, then the only technology would be then the HDSPA, which starts on ~1.8 Mbps.

3/ Can someone give me good parameters for the streaming for the mobile audio streaming?

Thanks a lot BR STeN

Upvotes: 1

Views: 1709

Answers (1)

Brad
Brad

Reputation: 163468

You have figured out the first part of this, that the audio is actually 16 bit, and that the bitrate specified here is for the compressor.

The second part is choosing a bitrate appropriate for mobile streaming. In my tests, I've found that you don't really want to go higher than 96kbit, but 64kbit is generally acceptable.

To get a decent audio quality at 64kbit, you can encode the stream in mono. If you prefer stereo, you will get many compression artifacts at this bitrate. Only AAC would be recomended at that point, which works very well at low bitrates.

At least in my area, the bandwidth just isn't there to reliably do anything higher, and this is on EvDO.

Upvotes: 2

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