audio digitization

Part of this article refers to the blog from Droidphone (http://blog.csdn.net/droidphone/article/details/6271122), about Alsa writing a very good article, just a few examples. This article is a combination of examples to analyze the ALSA audio driver.Development environment: ubuntu10.04Target board: linux-2.6.37 (view Linux kernel information via command uname-r)Compiler: arm-none-linux-gnueabi-(None on behalf of compiler creator, such as: FSL for Fre

Http://blog.csdn.net/dinggo/archive/2007/12/29/2002298.aspx AMR Audio Codec Table of Contents 1. Overview 2. AMR Code 3. AMR decoding 4. AMR frame reading algorithm 5. Resources 1. Overview Many smartphones now support multimedia features, especially audio and video playback, and the AMR file format is a widely supported audio file format for mobile phones. A

As the most well-known media player software in China, Storm audio and video has been in the market in 08 and is dedicated to creating a complete video playback platform for 150 million users. In this platform, not only the continuation of the Storm audio and video to the user's local storage environment of all kinds of audio and visual files of the universal pla

Author: Yang xingping The resources on the Internet are really rich and colorful, such as MP3, movie and TV series, and funny cartoons and Flash. However, in the face of the vast Internet, A lot of netizens often look at the Internet and sigh, because some resources are difficult to save to a local computer to listen to or watch them again using the conventional method. Today, we will introduce the "audio and video probe". This software not only finds

Audio terminologyIn this DOCUMENT Generic Terms Digital Audio Hardware and Accessories Audio Signal Path Android-specific Terms Sample Rate Conversion This document provides a glossary of audio-related terminology, including a list of widely used, generic terms and a list

Android Audio Analytics1 Android Audio System framework? Multimedia framework:The multimedia framework is responsible for encapsulating the playback/recording class, connecting the Android audio decoding library for audio software decoding, and connecting the high-pass Openmaxil interface. The upper app directly invoke

SummaryThis article introduces the principle and basic implementation process of VoIP, and analyzes the composition of audio latency in the Ethernet environment. The experimental results show that the audio latency in the Ethernet environment is mainly composed of the buffer latency and API call latency, and the most important part is the API call latency. This paper proposes a method to reduce API call lat

Small series of computer just reload Win7 system, found no sound, using Windows7 users will find in the lower right corner of the taskbar in the position of the volume icon shows a small red fork, put the mouse up later to show that the audio service is not running or not plugged into the speakers or headphones. There are two situations in which the "Audio service is not running" but the computer has sound,

1, click the "Insert" tab, click "Video"-"video on PC" To insert a video, the effect of inserting the following image as shown below. 2. After inserting the effect as shown in the following figure, the next step begins to trim the video. 3. Select the video, which will display the video tool (including the format and Playback tabs), click the Play tab, and then click Clip Video. 4, the "Clip Video" dialog box, you can drag the following figure in the circle

1. Import #import 2. Implementation Protocol e.g. @property (nonatomic, strong) Avaudiorecorder *audiorecorder; @property (nonatomic, strong) Avaudioplayer *audioplayer; Path of audio files saved after recording -(Nsurl *) audiorecordingpath{ Nsfilemanager *filemanager = [[Nsfilemanager alloc] init]; Nsurl *documentsfolderurl = [FileManager urlfordirectory:nsdocumentdirectory indomain:nsuserdomainmask Appropriateforurl:nil Create:no Error:nil]; N

1.2.1 Common formatsCommon audio formats are: CD format, WAVE (*. WAV), AIFF, AU, MP3, MIDI, WMA, RealAudio, VQF, Oggvorbis,AAC, APE. CDThe audio quality of the CD format is relatively high. So to speak the audio format, CD is naturally the leading pioneer. In most playback software, the "hitOpen file Type ", you can see the *.CDA format, which is the CD track. S

IOS audio playback (4): Converting AudioFileSource: http://msching.github.io/blog/2014/07/19/audio-in-ios-4/preface Next, the third articleAudioStreamFileLet's talk about this article.AudioFile. AndAudioStreamFileSameAudioFileYesAudioToolBoxIn the framework, it can also complete Step 1 described in the first article, read audio format information and perform fram

The previous article recorded the RGB/YUV video pixel data processing method, this article continues the previous article the content, records the PCM audio sampling data processing method. The location of the audio sample data in the video player's decoding process is shown.This paper introduces several PCM audio sampling data processing functions as follows:Sep

In iOS development, the most important framework for audio and video is the avfoundation framework. Starting from this article, we will focus on avfoundation-based audio usage and processing. To learn how to use audio, you must first understand the audio session. 1. What is an aud