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Questions tagged [adpcm]

Adaptive differential pulse-code modulation (ADPCM) is a variant of differential pulse-code modulation (DPCM) that varies the size of the quantization step, to allow further reduction of the required bandwidth for a given signal-to-noise ratio.

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How to convert headerless ima-adpcm raw file to wav using sox

I am trying to convert a raw file (header-less) to wav It is in ADPCM 16 rate 8000 I have tried three console commands sox -e ima-adpcm -r 8000 input.raw output.wav sox -e ima-adpcm -r 8000 -b 16 input.raw output.wav These trigger the same…
QGA
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OpenAL: alBufferData returns AL_INVALID_VALUE even though input variables *look* OK?

So, I'm building a threaded IMA ADPCM decoder streaming audio data to OpenAL (see below for short description) but I've run into some trouble. One of my issues is that sometimes my call to alBufferData: alBufferData(*bufferID, format, pcmData,…
happytrooper
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Why does my ADPCM decoder seem to oscillate?

I am writing code for an embedded processor (ARM Cortex-M4) The purpose of this code is to decode 4-bit ADPCM in Intel/DVI format (also called IMA format). I have encoded an ADPCM sample of a square wave using Python's audioop module. I have then…
Tom Oldbury
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Way to encode 8-bit per sample audio into 2-bits per sample

If ADPCM can store 16-bit per sample audio into 4-bit per sample, is there a way to store 8-bit per sample audio into 2-bit per sample?
Kyle Alexander Buan
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Web Audio Api Realtime streaming PCM ADPCM

I have a server that passes the client PCM or ADPCM data. I initially decided to use PCM because I did not want to deal with encoding and decoding. I got PCM to work however between each chunk of audio I heard glitches.(Sort of like clipping) So I…
Evren Bingøl
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create a wav header for ADPCM recorded data on iPhone

My requirement is to create a .wav file, and I had an existing code with ADPCM encoder already written. It was getting data in linear PCM and converting it to ADPCM and creating a wave header for the file. Now, I have modified the code, and I am…
user579951
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Play raw uncompressed sound with AudioQueue, no sound

I use three buffers with one queue, to play ADPCM data over network. The data is decoded from my app, and the decoded data (uncompressed pcm data) is verified correctly by playing from Audacity. However, I cannot hear any sound when playing from my…
nevo
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ffmpeg Unsupported codec adpcm_ima_wav when i want sending in RTP

when i want encode a wav file and send it with rtp in ffmpeg i receive an error that say "Unsupported codec adpcm_ima_wav" but i can encode this file with adpcm_ima_wav and save this file but i can not send with rtp in ffmpeg. ffmpeg -hide_banner…
GreenMan
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Dialogic ADPCM VOX file 6000 Hertz to Wave GSM in Alvas.Audio

How to convert Dialogic ADPCM VOX file 6000 samples per second to Wave GSM in Alvas.Audio?
Elena
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HTML5 audio Browsers unable to decode wav file encoded with IMA ADPCM

First, I apologize as I'm essentially new to working with audio. The web application I currently work on, designed using asp.net/vb.net, allows users to record and play back audio using the Nanogong applet (http://nanogong.ust.hk/doc_faq.html). We…
AmyW
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Stream and loop MS ADPCM (WAVE_FORMAT_ADPCM)

I'm trying to stream an MS ADPCM file using XAudio2 (in C++, but this problem doesn't appear to be language related). The file is encoded with ADPCMEncode.exe, this gives a WAV file with a format tag of WAVE_FORMAT_ADPCM. Like any stream, I create a…
subi211
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Play ADPCM stream on iOS (MS IMA 0x11)

I'm using the AudioUnit / RemoteIO API to achieve playback of streaming audio. Other formats such as a-law and u-law are working fine. Here is an example of how I am setting up the a-law format: audioFormat.mSampleRate =…
C-o-r-E
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Problems converting ADPCM to PCM in XNA

I'm looking to convert ADPCM data into PCM data from an XNA's .xnb file. (So many abbreviations!) I've used a couple of places for references,…
RayBatts
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How to play G726 ADPCM buffer?

I want to play the audio that was received from IP Camera. The format of compressed audio data is G726 ADPCM. I have searched for a few days on internet, but I haven't done it yet. I have tried many many ways to play back it. Tried to decode to PCM…
TTGroup
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What do the step size table and step size adaption tables look like for a 12 bit input conversion with ADPCM?

I'm following this guide on using ADPCM to encode 12-bit ADC values into 4-bit samples on an MSP430. It works well as-is, but it's designed to handle 16-bit ADC readings, so I am losing resolution with the current algorithm. I'm wondering how the…
Rohan Menon
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