I have a linux box hooked up to an amplifier via optical out, I use MPD to play music out through the amp. I also watch movies using a Popcorn Hour connected to the amp and to a projector. During daylight it's not really possible to use the projector so I want to watch TV programs on my Windows laptop, but still take advantage of the amp...
Is there a way to detect whether an FLV file contains video, audio or both? The flv file is streamed to a flash client, that needs to show a certain view depending on the data in wrapped in the flv file. ...
Hi, I create a video with image in real time. I need to add at this audio in real time. I record audio with AVAudioSession but this create a file, i need to get a byte, what library must i use?? thanks ...
I need to create a C++ application with a simple audio recording from microphone functionality. I can't say that there aren't enough audio APIs to do this! Pulse, ALSA, /dev/dsp, OpenAL, etc. My question is what is the current "Best practice" API? Pulse seems supported by most modern distros, but seems almost devoid of documentation....
What is the best API to utilize in developing an application that handles both realtime MIDI and audio input and output? This would be for an application that is used in the process of making music as opposed to playing audio or MIDI files. I'm aware that this may be a subjective question, but if you know of an API that is dominantly use...
Hi I am using the AudioRecord class to analize raw pcm bytes as it comes in the mic. So thats working nicely. Now i need convert the pcm bytes into decibel. I have a formula that takes sound presure in Pa into db. db = 20 * log10(Pa/ref Pa) So the question is the bytes i am getting from audiorecorder from the buffer what is it is it...
Hi, I want to play sounds from an internet server in my own program. But the sample codes Apple supplied concerned about sound play are all open an audio file, and then play it. I want to know how can I play PCM data from memory, which received from internet continuously. Either OpenAL or AudioQueue is OK. Thanks. ...
So basically I would like somehow that given an audio file as input (most likely mp3 or I can use some audio engine that will handle other types too) from my computer to control some LED lights so they will be something like an oscilloscope, like the one in winamp. What would I need to be able to do this? I'm interested in building thin...
Hi, I have certain sound files and will like to develop an app which allows to set those sound files as ringtones. Can someone let me know the way of implementing it? What are the API's that I need to use for this purpose? Hope to get the reply soon. Regards Sunil ...
For real-time multimedia tasks the low latency is essential. A stable low latency value makes it possible to use a computer for making music for example. As far as I know, under Windows systems there's a DPC latency thing that's quite crucial for ensuring the stability of the latency. You can read more about Deferred Procedure Calls her...
I'm wondering what's the easiest/best way to determine the magnitude of a given frequency in a sound. It's my understanding that a FFT function will return the magnitudes of all frequencies in a signal. I'm wondering if there is any shortcut I could use if I'm only concerned about a specific frequency. I'll be using the iPhone mic to r...
Just wondering if it's possible to go through a flac, mp3, wav, etc file and edit portions, or the entire file by removing sections based on a specific frequency range? So for example, I have a recording of a friend reciting a poem with a few percussion instruments in the background. Could I write a C program that goes through the entir...
Hi I need to extract musical features (note details->pitch, duration, rhythm, loudness, note start time) from a polyphonic (having 2 scores for treble and bass - bass may also have chords) MIDI file. I'm using the jMusic API to extract these details from a MIDI file. My approach is to go through each score, into parts, then phrases and ...
Please see the class I have created at http://textsnip.com/see/WAVinAS3 for parsing a WAVE file in ActionScript 3.0. This class is correctly pulling apart info from the file header & fmt chunks, isolating the data chunk, and creating a new ByteArray to store the data chunk. It takes in an uncompressed WAVE file with a format tag of 1. T...
Hi, this is a 2 part question. First off, is it possible to access the audio data in an MP3 independently of the ID3 tags, and secondly, is there any way to do so using available libraries? I recently consolidated my music collection from 3 computers and ended up with songs which had changed ID3 tags, but the audio data itself was unmod...
Hi, I'd like to take an existing mp3 file located on an SD card and arbitrarily crop it (e.g. crop from 0:12 to 1:14 in a 3 minute song). The only class that I've seen that seems remotely relevant to do this is the MediaRecorder class. My 'hope' would be to "record" an existing file like this: MediaRecorder recorder = new MediaRecorde...
I am currently trying to record compressed audio with the iPhone Simulator to a .caf container. More specifically I am using the IMA4 codec. It works fine if I have the Sample rate set to 44KHZ. But if I lower the setting to any other value (eg. 22KHZ, 16, or 8KHZ) the recorded file is being played back much slower?! This does not happen...
Hi! Is it possible to cut audio file with iPhone SDK? (file has .caf extension) I just need to cut off the silence at the beginning. (Also, maybe it's possible to write new file from the existing one with specified start and end time.) Thanks in advance! ...
Hi Anybody know how to programmatically generate audio podcast files with bookmarks that can be used in iTunes / iPod / iPhone / iPod touch? Specifically text bookmarks (bookmarks with titles) that the listener can skip to a specific point in time in the audio file. Also how to add the text transcription of the podcast's content. Eve...
Trying to figure out why setloopback needs to be set to true for microphone activity to be detected. The problem is the echo feedback when using a macbook with a built in mic. If anyone has some ideas about this let me know. Right now I'm experimenting with toggling gain, depending on activity to simulate echo reduction. Not optimal...