The next disruptive iPhone feature? High definition audio call | Hacker News Reader

The next disruptive iPhone feature? High definition audio call

thenextweb.com

15 pointsdavidedicillo16 comments

I'm sure that's part of the evolution of FaceTime technology, but the article's author doesn't seem to really understand the technology he's touting. If cell phone antennas result in poor audio quality, they will also result in poor data quality, and thus poor audio-over-data quality. Either the antenna works well or it doesn't.

Similarly, ALAC would be a horrible way to send voice calls over wireless. Lossy codecs will require less bandwidth and thus be less susceptible to dropouts on poor-quality connections.

And while I know almost nothing about codecs, I'm pretty sure you have to design one specifically for streaming - you can't just take a write-to-disk format like ALAC or FLAC and decide to stream it wirelessly.

Not only you need a codec designed for streaming, you also need it to be resistant to bit errors. This is a big technical issue that most people do not understand when they compare voip targeted codecs with cellular codecs. In regular voip communication, you might encounter an occasional dropped packet, but by and large, most packets make it to their destination and they arrive there intact. Voip codecs are designed with this scenario in mind. In cellular voice communication, a device has to accommodate for frequent bit errors in the packets it receives, and codecs are designed to cope with this (otherwise you'd get an inordinate number of bad packets that have to be dropped). This is why you need significantly more bits to achieve the same perceived audio quality with a cellular codec that with a traditional voip one. Yes, you can do regular voip over a mobile data connection, but the results will be substandard in less than perfect connectivity scenarios.

maybe this is a dumb question, but why are so many packets dropped in cellular technology? is it an issue of the way the network is built, or is there some sort of physical constraint? or something else?

I doubt phone antennas are the bottleneck, they're a pretty minor part of a huge, lumbering voice-transmission infrastructure. Much of that infrastructure is presumably expensively, archaic, and built assuming that audio traveling through it is compressed all to heck.

You can stream tunes in real time over data with quality far in excess of what a high-def voice call would need. There's bandwidth to spare on the data side of things.

This is a meandering article. Marco Arment's response at http://www.marco.org/2011/10/27/high-definition-audio conveys the point much more clearly and succinctly.

Audio and video codecs are generally stream/packet based. You'd really have to screw up the container format to make a codec completely incapable of streaming. (Like putting the last frame of video at the start and the first frame at the end of the file)

If you use a player like VLC you can generally watch videos while they are downloading.

The issue is more so whether the codec can handle dropped packets. It wouldn't surprise me if FLAC could not recover in such a case; usually lossless codecs employ something like Huffmann coding which places a large dictionary at the start of the file.

Low-latency is required for realtime applications, which many codecs are incapable of.

Subpar telephone audio quality is one of those things that is so pervasive that most people are probably only vaguely aware it's a problem.

I'm convinced that if you brought an engineer from the 1940s to today and showed him an iPhone, he'd be absolutely overwhelmed and ecstatic that technology has progressed so far. That is until you let him make a call. Then he'd ask you why the girl on the other end sounds the same as she did in 1940.

I was thinking about this the other day.

The voice quality on the majority of networks suck. I don't know a better way to put it. We can have HD video streaming to a phone but I can't have crystal clear audio?

Don't even get me started on conference calls and volume. Am I the only one that wishes the volume on my damn phone could go about 10x higher than the preprogrammed setting?

It would be nice if instead of creating another proprietary protocol, they'd just use something that's already in place http://en.wikipedia.org/wiki/Wideband_audio

Exactly. Telecom is basic infrastructure like the highway system. If Apple were building cars they'd want to have special super smooth tastefully designed toll roads that only Apple cars could run on.

I fully expect this to happen. iMessage is a clear shot across the carrier's bows -- in fact, I wouldn't be surprised if they'd have preferred that Apple go after voice first before the obscenely marked up texting market. They're getting gutted from the inside out, and I can only imagine the frantic rent-seeking that's going on even as we speak to get this sort of thing "sorted out".

I don't see this. Carriers already compete with messaging services like AIM creating AppleTalk-for-mobile doesn't seem that disruptive considering. The article's evidence looks more like ATT responding to a bifurcating market with no-text and text-heavy users. It's profitable for them to fold mid-level users into unlimited plans and attract more people who'd rather have the $15.

With HD audio you can hear absolutely everything in the background. We need signal compression in the frequency range to hear just our voice signals in the range we want to hear. You can't speak over HD audio in busy traffic or where there is significant ambient noise.

"How are you going to send high quality data, Mr. Anderson, when you can't even get signal?"

AGENT SMITH LOOKS AMUSED.

Apple had enough clout to leave the carriers silent for iMessage, but this could be the straw that breaks the innovation-fearing camel's back.

I'm almost certain they're planning it.

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