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Questions tagged [aac]

Advanced Audio Coding (AAC) is a standardized, lossy compression and encoding scheme for digital audio. Designed to be the successor of the MP3 format, AAC generally achieves better sound quality than MP3 at similar bit rates.

Advanced Audio Coding (AAC) is a standardized, lossy compression and encoding scheme for digital audio. Designed to be the successor of the MP3 format, AAC generally achieves better sound quality than MP3 at similar bit rates.

AAC has been standardized by ISO and IEC, as part of the MPEG-2 and MPEG-4 specifications.[3][4] Part of the AAC known as High-Efficiency Advanced Audio Coding (HE-AAC) which is part of MPEG-4 Audio is also adopted into digital radio standards like DAB+ and Digital Radio Mondiale, as well as mobile television standards DVB-H and ATSC-M/H.

AAC can be encapsulated in MP4, ADTS and ADIF formats. Use as well if the question is related to AAC encapsulated in ADTS and if the question is related to AAC encapsulated in MP4 container.

More information at AAC in wikipedia

614 questions
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How do I use CoreAudio's AudioConverter to encode AAC in real-time?

All the sample code I can find that uses AudioConverterRef focuses on use cases where I have all the data up-front (such as converting a file on disk). They commonly call AudioConverterFillComplexBuffer with the PCM to be converted as the…
nevyn
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avconv: getting aac to work. -strict experimental doesn't work

I am trying to get the following screencast command to work: avconv -f alsa -ar 44100 -ac 2 -i default -acodec aac -strict experimental -ab 320k -f x11grab -s 1024x600 -r 24 -i :0.0 -vcodec rawvideo screencast.mp4 But I still get the following…
Nicholas
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How to encode resampled PCM-audio to AAC using ffmpeg-API when input pcm samples count not equal 1024

I am working on capturing and streaming audio to RTMP server at a moment. I work under MacOS (in Xcode), so for capturing audio sample-buffer I use AVFoundation-framework. But for encoding and streaming I need to use ffmpeg-API and libfaac encoder.…
Aleksei2414904
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Using AVAssetWriter to create QuickTime movie from raw H.264 / AAC files

Using Mac OSX Objective-C, I'm trying to create a command line tool that takes a single H.264 and a single AAC file as inputs - encoded from the same source material - and, using AVAssetWriter, create a single QuickTime-compatible mov (and/or m4v)…
Chuck at Cimarron Systems
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Can I use AVCaptureSession to encode an AAC stream to memory?

I'm writing an iOS app that streams video and audio over the network. I am using AVCaptureSession to grab raw video frames using AVCaptureVideoDataOutput and encode them in software using x264. This works great. I wanted to do the same for audio,…
Avner
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How to record video in MPEG-2 TS output and ACC audio encoding format

When I set video format MPEG-2(Constant value 8) TS and audio format ACC(Constant value 3) it records video only without audio in ACC format. But it doesn't give any error. I tried it on Samsung Galaxy Tab(Honeycomb). Because MPEG-2TS supports on…
Suvam Roy
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ExtAudioFileWrite to m4a/aac failing on dual-core devices (ipad 2, iphone 4s)

I wrote a loop to encode pcm audio data generated by my app to aac using Extended Audio File Services. The encoding takes place in a background thread synchronously, and not in real-time. The encoding works flawlessly on ipad 1 and iphone 3gs/4 for…
roperklacks
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Packing RAW AAC into m4a container?

I have an Android app using FAAC to convert raw PCM into raw AAC, but now I don't know how it can be packed into m4a container. I've searched on the net and found a lot of info, but none of them solves my question. Most of them referring ffmpeg /…
JiangCat
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difference between audio data in .aac and .m4a files at the byte level

This is for trying to understand the aac file structure For simplicity we can assume m4a file with only aac audio (that is, no video) I am comparing an m4a file and an aac file made from the m4a file using the faac library A screenshot of the…
user13267
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Video and Audio Sychronization issue

I am saving frames to H264 format and I saved audio to aac format. Then I concatenate of these format to creating mp4 format using ffmpeg player in android but When I concatenate Audio and Video, audio getting back of video they aren't playing at…
Diego
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How to determine if an audio track is a Dolby Pro Logic II mixdown

I'm trying to find out if there's a way to determine if an AAC-encoded audio track is encoded with Dolby Pro Logic II data. Is there a way of examining the file such that you can see this information? I have for example encoded a media file in…
WheresWardy
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How to decode AAC compressed frames to PCM using AudioConverterFillComplexBuffer iOS

I want to implement SIP calls in my application, and first problem, that I need to solve, is converting audio from compressed AAC format with ADTS header to linear PCM. My input data is an NSArray of ADTS frames with different framesize. Each frame…
avsmirnov567
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Write seekable AAC audio stream into MP4 file with FFMPEG

I'm trying to write an AAC audio stream into an mp4 file using the FFMPEG libraries. I am using a custom IO context that writes directly to a socket so I have to set ioContext->seekable = 0. To make this work I had to add the "movflags" empty_moov…
lex82
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What is the algorithm to convert an mp3 file to a wav file?

What is the algorithm to convert an mp3 file to a wav file?
Evil Nodoer
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How to enable the experimental AAC encoder for VLC and record AAC sound from the microphone?

I managed to record mp3 with VLC 2.1.5 on MacOSX 10.9.2 by using this command: ./VLC -vvv qtsound://AppleHDAEngineInput:1B,0,1,0:1 --sout "#transcode{acodec=mp3,ab=128}:standard{access=file,mux=mp3,dst=~/Desktop/Recording.mp3}" However I need to…
DevtelSoftware
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