m4a | 易学教程

How to convert WAV file to M4A?

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问题 Is there any way to convert my recorded .WAV file to .M4A file in iOS? And also I have to convert .M4A file to .WAV file. I tried with Audio Queue Services, but I am not able to do. 回答1: This post: From iPod Library to PCM Samples in Far Fewer Steps Than Were Previously Necessary describes how to load a file from the users ipod library and write it to the file system as a linear pcm (wav) file. I believe that the change that you will need to make to the code to load a file from the file

How to record using AVAudioRecorder without the .caf container?

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问题 I am using a AVAudioRecorder instance to record with the setting for AVFormatIDKey set to kAudioFormatMPEG4AAC . It records the audio in AAC format but a .caf audio container packages the audio file. (I can see the caff header in the recorder file). How do I record so that the caff container is not there but in pure m4a format so that I can use the files across platforms. 回答1: Found the answer. There is a weird way the AVAudioRecorder works. The format in which the AVAudioRecorder will save

How can I export an mp3 file from an iOS device's iPod library?

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In my iOS application I'm trying to export an mp3 file from the iPod library to the app's documents directory on the device. Currently I'm trying to use AVAssetExportSession but it's not working for mp3 files. It works well for m4a files. Is exporting an mp3 file possible using AVAssetExportSession? What is the appropriate outputFileType for AVAssetExportSession? ( AVFileTypeAppleM4A works for m4a files) Thanks! urish I am facing the same problem. Unfortunately, non of the iOS frameworks (AVFoundation, CoreMedia, etc) support encoding to MP3. An answer to a similar question suggest using the

将任意音频格式文件转换成16K采样率16bit的wav文件

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此转换需要使用ffmpeg 假设有目录 d:\录音目录有张三.m4a, 李四.m4a xxx.m4a（其他任意格式音频触类旁通可以把 *.m4a改成*.*）。批量转换成采样率16K,有符号,16bit 小端wav格式音频。新建一个批处理文件，放在d:\录音\convert.bat,代码如下 @echo off title 正在批量转换 if not exist wav mkdir wav for /f %%i in ('dir /b *.m4a') do ffmpeg -i %%i -acodec pcm_s16le -ac 1 -ar 16000 wav\%%~ni.wav -y pause 转换过程如下：来源：博客园作者：你不知道的浪漫链接：https://www.cnblogs.com/passedbylove/p/11764227.html

将任意音频格式文件转换成16K采样率16bit的wav文件

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此转换需要使用ffmpeg 假设有目录 d:\录音目录有张三.m4a, 李四.m4a xxx.m4a（其他任意格式音频触类旁通可以把 *.m4a改成*.*）。批量转换成采样率16K,有符号,16bit 小端wav格式音频。新建一个批处理文件，放在d:\录音\convert.bat,代码如下 @echo off title 正在批量转换 if not exist wav mkdir wav for /f %%i in ('dir /b *.m4a') do ffmpeg -i %%i -acodec pcm_s16le -ac 1 -ar 16000 wav\%%~ni.wav -y pause 转换过程如下：最终在wav文件下获得转换过的文件来源： https://www.cnblogs.com/passedbylove/p/11764227.html

iOS - How to convert m4a to mp3?

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问题 I have searched through many websites on the internet, but there's no sample code for converting m4a to mp3. Does anyone know how to do this in iOS? Thank~ 回答1: You can use AVAudioFile to read the m4a, and another AVAudioFile to write the mp3 with appropriate format settings. But this thread suggests mp3 encoding in iOS is not possible with CoreAudio. 来源： https://stackoverflow.com/questions/19062157/ios-how-to-convert-m4a-to-mp3

Packing RAW AAC into m4a container?

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问题 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 / mp4box command line, but what I need is to solve this in Android environment, which means either Java Eclipse, or JNI. Any hint please? 回答1: This AACEncoder Project on Github seems to be great! And it works for me. It actually has the ability encode

Java play AAC encoded audio ( JAAD decoder )

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I have struggled with playing aac encoded audio files with Java a while now. We had a group project at the end of our first semester and wanted to have a background music and few soundeffects in there. At the end we used WAV files, as we couldn't get the AAC's to play. This weekend I gave it another try and searched along again, and have got a working code searched together from different sites, but nowhere was a complete working solution. For a more comfortable usage in future projects I made me a small library for aac playback. As it was hard to find th working solution, I wanted to share it

Java play AAC encoded audio ( JAAD decoder )

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问题 I have struggled with playing aac encoded audio files with Java a while now. We had a group project at the end of our first semester and wanted to have a background music and few soundeffects in there. At the end we used WAV files, as we couldn't get the AAC's to play. 回答1: This weekend I gave it another try and searched along again, and have got a working code searched together from different sites, but nowhere was a complete working solution. For a more comfortable usage in future projects

How do I programmatically convert mp3 to an itunes-playable aac/m4a file?

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I've been looking for a way to convert an mp3 to aac programmatically or via the command line with no luck. Ideally, I'd have a snippet of code that I could call from my rails app that converts an mp3 to an aac. I installed ffmpeg and libfaac and was able to create an aac file with the following command: ffmpeg -i test.mp3 -acodec libfaac -ab 163840 dest.aac When i change the output file's name to dest.m4a, it doesn't play in iTunes. Thanks! FFmpeg provides AAC encoding facilities if you've compiled them in. If you are using Windows you can grab full binaries from here ffmpeg -i source.mp3