Background Audio Player Windows Phone Stutter - audio

I've made a simple app for Windows Phone 8 using BackgroundAudioPlayer and I've encountered a strange problem:
While I'm trying to play a large mp3 file (for example 70Mb) sometimes (1% of cases) music starts but I hear something like somebody was stuttering (audio player jams?). If I pause, rewind some seconds and play again it works perfect.

Related

Ableton Live 11 Lite: Lagging or distorted delay of recording

I'm using Ableton Live 11 Lite while recording a cover, and discovered that all of my recording comes out as a jittery mess all of the sudden. I'm using a Focusrite Scarlett Solo, a Squier Telecaster, Maestro Ranger Over-Drive pedal, and an Audio-Technica Mic. It's a new project, I have a metronome set up for recording Privately Owned Spiral Galaxy, and the audio interface splits the mic and guitar into separate tracks that I'm trying to record individually. I posted a sample of the God-awful sound of it recording here for reference.
P.S. I know this isn't the correct page but there's hardly any Ableton/DAW questions on the Music page and no answers really, as opposed to the several I found on SO.
I would start with playing with your buffer size in your Audio driver.

Delay Audio on Windows 10 by a second

Is there a way to universally delay audio in Windows 10 (I have Realtek Hi-Definiton Audio) as an example.
I have 2 reasons why I want to accomplish this
1) My audio is playing a quarter of a second before the video plays (out of sync). This is consistent in youtube, vlc media player, windows media player, pretty much any video content... the mouth will move 1/4 second after the audio. The delay builds up overtime as well, about 5 minutes in it becomes unbearable.
2) Unrelated to #1 I want to scan the audio and edit it in near real time. Searching for certain sounds and also reading certain subtitles.

Bluetooth headphone music quality deteriorates when launching iOS simulator

The situation goes a little something like this:
I am programming Xcode whilst concurrently listening to music on my Bluetooth headphones... you know to block out the world.
Then, I go to launch my app in the iOS simulator and BOOM all of a sudden my crystal clear music becomes garbled and super low quality like it is playing in a bathtub 2 blocks away... in the 1940s.
Note: the quality deterioration does NOT occur if I am playing music on my laptop or cinema display and I launch the sim. It seems to be exclusively a Sim -> Bluetooth issue.
The problem is more than just annoying. Because often after stopping the simulator the crappy bathtub quality music continues. To fix it I have to open sound preferences in OSX and briefly toggle back to my laptop sound and then back to my Bluetooth headphones.
This is a big deal because I launch the simulator 50x a day and have to do this toggle thing every time as well as suffer listening to 40s era mono ham radio quality music.
For your information, the headphones I am using are Plantronics BackBeat Pro and I am up to date on firmware. I am on OSX 10.11.4 and Xcode 7.3... but this problem has persisted through all versions for 2+ years now. Can you save me from the 1940s?
I've managed to fix it, and it actually seems to be a microphone issue. Go to System Preferences -> Sound, select the Input tab and set Internal Microphone as the input (mine was set with my headphones').
Crappy sound goes way after that =)
EDIT (May 30 2018):
I've found out an easier way to do the same as above. Instead of opening the System Preferences, you can just go to the Mac OSX toolbar, press Option (alt) + click on the sound icon and then select "Internal Microphone" from the "Input Device" list. Print screen as follows.
If you're using Xcode 9 or higher, you can set a default audio input and output for the simulator. This can be done by launching the simulator from Xcode and navigating to I/O > Audio Input within the menu bar and selecting Internal Microphone. This solution will save your audio preference so you won't have to change it on every launch.
On Simulator, Select;
I/O -> Audio Input -> Macbook [Pro]
Done.
Seems like years of suffering are finally over, Xcode 12 Beta Release Notes:
Simulator defaults to the internal microphone unless you explicitly choose a different audio source. This avoids triggering phone call mode on Bluetooth headsets which degrades audio quality while listening to music. (59338925, 59803381)
You can also switch to Mac's internal mic in System Preferences -> Sound, that's how I usually fix this bug (I have Sony Wh-1000XM3)

same mp3 files behave differently in iPhone app

I have 2 mp3 files that are nearly identical. The first file refused to stream down and play in my Appcelerator iPhone app that I am developing:
http://www.zerogravpro.com/temp/bad.mp3 (you'll find you can play this just fine in your browser, or download it and it plays fine)
This is 100% replicatable; it's not sporadic at all. The actual behavior is that the file begins to play in the iphone mediaPlayer for just a split second, then stops with some kind of "unknown" error. So then I took that file, opened it in audacity, removed the first split-second of silence from the beginning of the clip, and re-generated the mp3:
http://www.zerogravpro.com/temp/good.mp3
And this one works perfectly in the iphone app! 100% success each and every time. I have many mp3 files that are similar to bad.mp3 in that they play fine in any audio device, but error out when streaming/playing in iphone's media player. Audacity fixed it somehow and I need to know how/why, so that I can automate the fix in my hundreds of other mp3 files. I'd love to not have to open hundreds of files in Audacity and re-save. There must be some way to automate these fixes. How did Audacity fix the file? What did it do? I can only think of 2 possibilities:
The existence of a split second of silence at the beginning of the clip chokes iphone
Audacity fixes something non-obvious in the mp3
Experts: Any idea what the difference is between these 2 files, and how I could automatically turn "bad" mp3s into good ones, from some command-line tool or something? Thanks all.
I discovered that the only difference between the files that actually matter is the size. iPhone apps (at least in the simulator), when using the audio streaming library, choke on any file under 40Kb. So you have to use the standard sound library for the smaller files.

I hear clicking in audio with a DirectShow graph created with Graph Edit yet player software on my PC plays audio smoothly

I have a DirectShow application that I built with Delphi 6 using the DSPACK component library. For two days I have been trying to solve a problem with audio playback. When I run the filter graph I create I hear repetitive clicks in the playback. What was really confusing was that the audio file I created simultaneously with my filter graph had clean continuous audio, not gaps. So I knew that the audio buffers were being delivered properly but something I was doing was "jamming up" the "live" playback. Or so I thought. I spent two days diagnosing the problem looking for semaphores being held too long (locks) or perhaps timestamp problems, which I documented in this other Stack Overflow post:
Getting stuttering during rendering of my DirectShow filter despite output file being "smooth"
A few minutes ago I decided to try a test with the Graph Edit utility. I created a dead simple graph consisting of just the capture device I was using (VOIP phone microphone), and the renderer device I was using (HD ATI Rear Audio output to headphones). Two filters total. Much to my surprise I heard the same clicking. So here was a case that did not involve my code at all and I heard clicking.
Then I changed the audio renderer in the Graph Edit created filter graph to the VOIP phone ear piece. The clicking went away.
Now I know there's a way to get smooth audio on ut the ATI Rear Audio device since its the preferred audio output device and everything from videos I play on my PC to wave files I play on it sound flawless. So are the other software programs doing something different than just connecting filters? I am wondering if perhaps the default mode for the HD ATI Rear Audio is without double-buffering and perhaps those other software programs know how to enable that feature? Or are they doing something else, perhaps using another DirectShow or DirectSound filter or technique for example, to make the audio play smoothly on the HD ATI Rear Audio renderer?
What you possibly having (depends on actual stuttering though) is that when you are using capture and playback devices backed by different hardware, their sampling rates slightly differ. For example, you capture 22050 Hz at actual rate of (22050 - 2%) Hz and you play it back with hardware consuming bytes at (22050 + 2%) Hz.
Now obviously this won't work out smooth: eventually playback will experience data underlow... If you save into file and play back from file, it will go smooth as the file will be able to supply data at the rate of playback device. If capture and playback devices are the same hardware, they are likely to use shared "hardware" clock and rates match.
The problem is known as "rate matcing" and is discussed on MSDN in Live Sources section.

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