I've written a basic SL4 application to capture audio data from the microphone using CaptureSource. The trouble is, it's raw PCM output - which means huge and uncompressed. Given that I need this application to run purely within a SL4 environment, how can I compress the PCM audio data into something that can be delivered to a remote ser...
I have several chunks of PCM audio (G.711) in my C++ application. I would like to visualize the different audio volume in each of these chunks. My first attempt was to calculate the average of the sample values for each chunk and use that as an a volume indicator, but this doesn't work well. I do get 0 for chunks with silence and differ...
What is an algorithm for joining PCM files? I have several PCM files I need to Join them in a way like speakers are speac at the same time. So How to Join PCM files? ...
First I am going to broadly state what I'm trying to do and ask for advice. Then I will explain my current approach and ask for answers to my current problems. Problem I have an MP3 file of a person speaking. I'd like to split it up into segments roughly corresponding to a sentence or phrase. (I'd do it manually, but we are talking ...
I'm attempting to port an application that plays chiptunes (NSF, SPC, etc) music files from Java SE to Android. The Android API seems to lack the javax multimedia classes that this application uses to output raw PCM audio. The closest analog I've found in the API is AudioTrack and so I've been wrestling with that. However, when I try to...
I have an app that is streaming audio content and sometimes it just stops all of the suddent. the logcat windows shows -- AudioHardware pcm playback is going to standby and that's it. I saw on another thread (pun intended) that someone was saying it was because he was using too many threads. Could that really be causing this? Could...
I have a situation where I need to trim a small amount of audio from the beginning of a recorded clip (generally somewhere between 110-150ms, it is an inconsistent amount). I'm recording in 44100 frequency and 16 bitrate. This is the code I'm using: public function get trimmedData():ByteArray { var ba:ByteArray = new ByteArray(...
I am looking to use 'Packet Loss Concealment' to conceal lost PCM frames in an audio stream. Unfortunately, I cannot find a library that is accessible without all the licensing restrictions and code bloat (...up for some suggestions though). I have located some GPL code written by Steve Underwood for the Asterisk project which implemen...
I was looking into System.Media.SoundPlayer and NAudio, and AFAIK they only play WAVE streams. The WAVE file is composed of the pure PCM data plus a format header. I don't want to provide this header in the WAVE format. I want to pass the parameters (bitrate, etc) programatically ...
i created a simple voice recording using wav format. my problem is i wanted it to save as PCM format using Tbass components form http://www.un4seen.com. My compiler is delphi. or convertion from mp3/wav to pcm. ...
I have Bass component from http://www.un4seen.com/bass.html. I load mp3 and triying to change the format to PCM but it wont do nothing? or any suggestion will be appreciated. ...
I am studying a sound converting algorithm where an array of signed shorts is received. At a given point in the algorithm it converts the samples from 16 bits to 14 bits, and it does it like this: int16_t sample = (old_sample + 2) >> 2; For me its clear that the shifting is needed as we want to get rid of the least 2 significant bits,...
Please bear with me as my understanding of audio codec is limited. I have this audio source from a IPCAM (through a htto//... CGI interface). I am trying to write several client programs to play this audio source on Windows, MAC, as well as Android phone. The audio is encoded in G711 (PCM ulaw). Do I need to decode the PCM audio data...
As a small experimental music piece I am attempting to program a song in standard C. The code outputs a raw PCM file which can be imported into Audacity. At the moment everything works as expected, but I'm encountering problems when trying to write each sample as 16 bit as opposed to the current 8 bit I am using. Up until the point of b...
I would like to start studying the .wav specimen by compairing two files. like returning a result of duration, accent, pronounciation in percentage. etc. or any code that comparing/analyzing the .wav ...
I'm writing an application that uses the Python Gstreamer bindings to play audio, but I'm now trying to also just decode audio -- that is, I'd like to read data using a decodebin and receive a raw PCM buffer. Specifically, I want to read chunks of the file incrementally rather than reading the whole file into memory. Some specific quest...
As a warning, I'm not super savvy with DSP so this may be silly. I've got a callback method in an application that takes a float buffer and writes it to a queue, and then eventually to a file. The callback method looks like this: FMOD_RESULT F_CALLBACK dspCallback (FMOD_DSP_STATE *dsp_state, float *inbuffer, float *outbuffer, ...
I'm currently trying to decipher WAV files. From headers to the PCM data. I've found a PDF (http://www.tdt.com/T2Support/technical_notes/tn0132.pdf) detailing the anatomy of a WAV file, and I've been able to extract and make sense of the appropriate header data using Ghex2. But my questions are: Why are the integers bytes stored backw...
I'm trying to get raw audio data from a file (i'm used to seeing floating point values between -1 and 1). I'm trying to pull this data out of the buffers in real time so that I can provide some type of metering for the app. I'm basically reading the whole file into memory using AudioFileReadPackets. I've create a RemoteIO audio unit to...
I need to convert an AMR (Adaptive Multi-Rate) audio file recorded in a phone (as a Stream object) to a PCM uncompressed wav audio Stream so it can be processed afterwards for speech recognition. The Speech Recognition doesn't like the AMR format. This is going to be a server application using the Microsoft Speech Platform. I am not sure...