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Why don’t podcasts use VBR MP3s? Because iOS and macOS don’t accurately seek them

marco.org

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Re: Why don’t podcasts use VBR MP3s? Because iOS and macOS don’t accurately seek them

#21

Post by derefr »

Analemma_ wrote: post #4

If you want more context to this, there's a lot more in the most recent ATP podcast (with timestamp link included in the article). Which kind of highlights a problem that I think is only going to grow over time - the general greatness of podcasts has one big black spot in that they're tough to share. I've seen so many discussions recently where there was awesome additional context or info in a recent podcast, but it…

> I don't have a great solution to this; some kind of automatic transcription maybe?

This was the original goal of YouTube, as a project: automatic video transcription to enable better accessibility and indexibility for audio/video. It's theoretically in there, but it doesn't do well at all. I'm honestly surprised it doesn't do better, given the Google Voice dataset that's likely backing it.

Re: Why don’t podcasts use VBR MP3s? Because iOS and macOS don’t accurately seek them

#22

Post by archagon »

cjensen wrote: post #20
archagon wrote: post #16

Earlier quoted context omitted.

I just don't understand why Marco has bitten so hard into this problem. It doesn't matter at all . Everybody skips the ATP theme song anyway, and VBR will only negligibly improve quality of the rest of the show ( as Marco himself has pointed out ). And it's not like the theme song sounds bad in its current state! I have never noticed any artifacts or flaws in the recording at all. This is almost literally only someth…

The ATP theme song by Johnathan Mann is unexpectedly awesome, and I never ever skip it. And as Marco pointed out in the ATP episode, this also affects any musical interludes or short musical samples within any podcast.

Yeah, I'm sure lots of people listen to it all the way through. I did for a while myself. But it's not worth inconveniencing so many of your listeners just to make your theme song (or very occasional clips) sound a tiny bit better — especially considering the fact that most people listen to podcasts in their car or even through the iPhone speaker, as Marco himself discovered from his analytics. Others have already noted that the easy solution to this problem exists in the form of AAC, which is supported ubiquitously at this point. Another solution is to just use 128kbps CBR; a 1.3x size increase is really not that big of a big deal, and 128 is transparent for many use cases.

Marco's solution is way, way out of proportion to the actual "problem". You'd think the guy who so often kvetches about Apple prioritizing design over function would know better than to make the same mistake!

Also: I know you don't air your dirty laundry in front of your audience, but I'm a bit disappointed that a careful and analytical engineer like Siracusa didn't call Marco out on this nonsense. (Especially after the .marcosweirdformat discussion, which was downright comical given the inconsequential nature of the problem in the first place.)

Re: Why don’t podcasts use VBR MP3s? Because iOS and macOS don’t accurately seek them

#23

Post by derefr »

raverbashing wrote: post #11
Analemma_ wrote: post #4

If you want more context to this, there's a lot more in the most recent ATP podcast (with timestamp link included in the article). Which kind of highlights a problem that I think is only going to grow over time - the general greatness of podcasts has one big black spot in that they're tough to share. I've seen so many discussions recently where there was awesome additional context or info in a recent podcast, but it…

I like podcasts, but they're unnerving to me. It's too much time wasted to get to the point. And as opposed to music, I can't program properly when listening to them Not to mention a lot of podcasters act in a radio way (which make sense for radio), with repetitions, talking slowly, endless introductions, chit chat, etc

The "radio stuff" isn't nearly as much of an irritant if you're listening to a podcast while commuting.

It's still kind of grating when you listen to a whole bunch of episodes of something in a row, though. There needs to be markers in the files and software that can cut off the intro/ending of the "internal" episodes in a playlist. Like a much more drastic version of gapless playback.

Re: Why don’t podcasts use VBR MP3s? Because iOS and macOS don’t accurately seek them

#24

Post by derefr »

colejohnson66 wrote: post #10
zymhan wrote: post #6

So is this why I have weird problems fast-forwarding through some NPR podcasts? I'll find myself at the end of the podcast (as indicated by the time bar), but the podcast itself is still playing. Man, Apple really is neglecting podcasts. Reminds of an article I read recently - "Podcasts Surge, but Producers Fear Apple Isn’t Listening" http://www.nytimes.com/2016/05/08/business/media/podcasts-su...

It's not Apple's fault; It's MP3 in general. Seeking in VBR MP3s is hard unless you decode the whole file and make note of the offsets for timing.

And decoding the whole file, in turn, would be easy in any other use-case (iTunes does this for "gapless playback" calculation) but podcasts are quite often streamed, and only once.

Probably the simplest "clever hack", if Apple wanted to fix this on their own, would be for all the podcast feeds registered through iTMS to get their files retrieved by the iTMS servers once, chewed through to calculate this information, and then all the calculated "keyframe" offsets injected as an opaque extra data field for each feed item of the iTMS-served podcast feed, where the Podcasts app can pick it up.

Re: Why don’t podcasts use VBR MP3s? Because iOS and macOS don’t accurately seek them

#25

Post by astrange »

caiob wrote: post #13

> VBR encoding is far more space-efficient and better-sounding than constant-bitrate (CBR) encoding While this may be true for podcasts, it's def false for music files.

VBR is a strict superset of CBR (= all CBR files are VBR), so this has to always be true.

BTW, if you're going to claim any mp3 encoding is better sounding than another one, I hope you've done an ABX test.

Re: Why don’t podcasts use VBR MP3s? Because iOS and macOS don’t accurately seek them

#26

Post by aianus »

drzaiusapelord wrote: post #17
Apreche wrote: post #7

That's not the only reason. We have been podcasting for over 10 years, and early on we tried to use VBR MP3s because we are teach people who know about that sort of thing. As it turns out, not everyone is listening using a modern device. When we tried VBR a significant number of people could not listen because their MP3 playing hardware/software of choice did not support VBR files properly. They didn't realize this w…

VBR have been the red-headed step-child of MP3 since the beginning. I have no idea why, maybe it was difficult to write good encoders and decoders for it for back in the day. The few times I used them, I found trivial space savings compared to a CBR and to be honest I thought I could hear a difference (maybe its not humanly possible if the implementation of the encoder/decoder is good but what if the implementation i…

iPhone storage and cellular bandwidth are still extremely expensive. Over $100 for a measly 16gb of storage or 4gb of LTE.

Re: Why don’t podcasts use VBR MP3s? Because iOS and macOS don’t accurately seek them

#27

Post by mwfunk »

archagon wrote: post #16
Analemma_ wrote: post #4

If you want more context to this, there's a lot more in the most recent ATP podcast (with timestamp link included in the article). Which kind of highlights a problem that I think is only going to grow over time - the general greatness of podcasts has one big black spot in that they're tough to share. I've seen so many discussions recently where there was awesome additional context or info in a recent podcast, but it…

I just don't understand why Marco has bitten so hard into this problem. It doesn't matter at all . Everybody skips the ATP theme song anyway, and VBR will only negligibly improve quality of the rest of the show ( as Marco himself has pointed out ). And it's not like the theme song sounds bad in its current state! I have never noticed any artifacts or flaws in the recording at all. This is almost literally only someth…

It sounds like he got into it because it piqued his interest so he did a deep dive on the subject. Nothing wrong with that. I will get frustrated with people sometimes for not doing things that they ought to be doing, but I would never sh*t on someone for following their bliss and spending their hobby time on things I personally am not interested in. If this pisses you off then I can't imagine what sort of vitriol you would direct at someone who is into, say, quilting. "Aren't quilts solved problems already?!? You just go down to Target and buy one, WTF people!"

Re: Why don’t podcasts use VBR MP3s? Because iOS and macOS don’t accurately seek them

#28

Post by archagon »

mwfunk wrote: post #27
archagon wrote: post #16

Earlier quoted context omitted.

I just don't understand why Marco has bitten so hard into this problem. It doesn't matter at all . Everybody skips the ATP theme song anyway, and VBR will only negligibly improve quality of the rest of the show ( as Marco himself has pointed out ). And it's not like the theme song sounds bad in its current state! I have never noticed any artifacts or flaws in the recording at all. This is almost literally only someth…

It sounds like he got into it because it piqued his interest so he did a deep dive on the subject. Nothing wrong with that. I will get frustrated with people sometimes for not doing things that they ought to be doing, but I would never sh*t on someone for following their bliss and spending their hobby time on things I personally am not interested in. If this pisses you off then I can't imagine what sort of vitriol yo…

When your solution to an incredibly minor and easily-solvable problem is to ask people to bug Apple engineers about adding new features to a decade-old encoder, maybe you're on the wrong track.

I'm frustrated by Marco's extreme fussiness, not his curiosity. (And there's no doubt his curiosity often leads to interesting places. I learned some great tidbits about MP3 encoding in the last few episodes!)

Re: Why don’t podcasts use VBR MP3s? Because iOS and macOS don’t accurately seek them

#29

Post by pierrec »

There are many degrees of VBR MP3 seeking support, and it's often surprisingly bad. In the case of Firefox's element, it was very poor (nearly unusable in my testing) until a few months ago:

https://bugzilla.mozilla.org/show_bug.cgi?id=994561

https://bugzilla.mozilla.org/show_bug.cgi?id=1163667

I had a fun time testing different js audio players, and going though their many confused bug reports, issues and threads all stemming from this. Even if Apple fixes their stuff, I still wouldn't use VBR MP3 for anything that's going to get streamed. There's always going to be some platforms that screw it up, and even a future browser introducing poor seeking seems very possible.

Re: Why don’t podcasts use VBR MP3s? Because iOS and macOS don’t accurately seek them

#30

Post by skrause »

jsmthrowaway wrote: post #5
Analemma_ wrote: post #4

If you want more context to this, there's a lot more in the most recent ATP podcast (with timestamp link included in the article). Which kind of highlights a problem that I think is only going to grow over time - the general greatness of podcasts has one big black spot in that they're tough to share. I've seen so many discussions recently where there was awesome additional context or info in a recent podcast, but it…

The solution is AAC, regarding which a number of prominent podcasters introduced FUD several years ago and now the podcasting industry is reluctant to give up MP3 -- unlike pretty much every other audio-related industry in the world. Seriously, MP3 was on its way out the year the Backstreet Boys released that song, and it surprises me that people still stick to it despite the VBR thing being a shitty problem in softw…

The problem with AAC is in the container format, as Marco explains in his podcast: While some important metadata like chapter marks which a podcast player might want to display are within the first KB in an MP3 file, this same information is interleaved somewhere in the stream in AAC.

Which means that you can't have all features when streaming an AAC file, in a time when streaming podcasts is getting more popular every day. You first have to download the whole file before you can display e.g. chapter information.

Of course you could just embed that information in the RSS feed, but you could do the same with jump tables for VBR MP3s. So AAC does not solve all your problems, you just get a different set of problems.

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