I'm using AVPlayer to play local .mp3 file and audio stream from server.
And i want to play local .pcm file too.
NSArray *paths=NSSearchPathForDirectoriesInDomains(NSDocumentDirectory
, NSUserDomainMask
, YES);
NSString * voiceFile = [[paths objectAtIndex:0] stringByAppendingPathComponent:#"OutPut.pcm"];
But it didn't work. i got unknown error.
It seems AudioQueue can play .pcm correctly.
But is there a sample way can let AVPlayer direct play .pcm just like .mp3?
Neither .pcm as a file extension or PCM data specifies a readable format. The player cannot recognize an arbitrary data stream. It is certainly capable of reading file formats which contain PCM data, but this PCM representation is missing several things typical audio file formats represent:
Sample Rate
Sample Size
Sample Format
Channel Count
and so on.
You should instead save that PCM data in an audio file format the player supports (e.g. a WAV file).
If you prefer to simply stream PCM audio information and you know the stream format, you can approach that problem using an AudioQueue.
Related
I'm working on a project where I'd like to play raw PCM data for IOS using swift. So far I've been able to load the PCM data from a local file into a swift Data variable like so
let audioData = try Data(contentsOf: fileURL) //Read data into data var
where fileURL contains the path to a PCM file.
Next, I'd like to play the audioData somehow; currently my ideas are to either
add a WAV header onto the audioData, write the data to file, then play it using AVAudioPlayer
somehow copy the data over to a AVAudioPCMBuffer and play it from the buffer using AVAudioEngine
Unfortunately, since I'm very new to swift and audio in general I'm pretty lost on how to actually program either of these routes
I am creating a bot that will record the Microsoft team live sessions. Audio recording is working fine but facing problems in generating the video file. The process I am following is that I am converting the video data into a byte array and then writing the data to a video format file.
I am adding some code snippets, I have examined so far.
1. Stream videoStream = new FileStream(videoFilePath, FileMode.Create);
BinaryWriter videoStreamWriter = new BinaryWriter(videoStream);
videoStreamWriter.Write(videoBytesArray, 0, videoBytesArray.Length);
videoStreamWriter.Close();
2. System.IO.File.WriteAllBytes(videoFilePath, videoBytesArray);
The generated files from the above code snippets are of an unsupported format.
It may be because of the data receiving from the session.
I am receiving the data through the Local media session's Video Socket on VideoMediaReceived Event (ICall.ILocalMediaSession.VideoSockets). The Video Color Format of the data that the socket is receiving is of H264 Format.
A similar problem I encountered when creating the audio file. For that, I utilized the WaveFormat package for creating an audio file.
So, Is there any library/method to convert the byte array to a video file of any format?
#Murtaza, you can try this and see if it helps. If the byte array is already a video stream then, simply you can serialize it to the disk with the extension mp4. (If it's an MP4 encoded stream).
Stream t = new FileStream("video.mp4", FileMode.Create);
BinaryWriter b = new BinaryWriter(t);
b.Write(videoData);
t.Close();
I have extracted the audio data from .m4a file using mp4v2 library (sample-by-sample). Does this library have function that decodes the data? Anybody with experience with this library and can provide some help?
The documentation says:
MP4ReadSample function reads the specified sample from the specified track.
Typically this sample is then decoded in a codec dependent fashion and
rendered in an appropriate fashion.
I am interesed in decoding the output.
Thanks in advance.
You tagged MP4(video data) and M4A(audio data). Since you are extracting from M4A, I can only imagine you actually have either AAC or MP3 audio data.
Each extracted sample (bytes) is audio frame.
To make a playable MP3 file : Simply join all MP3 frames' bytes together. Save as .mp3 to play later.
To make a playable AAC file : For each AAC frame, first create an ADTS header (7 bytes) followed by that frame's data. You can test your header bytes here (site shows what your byte values mean). When all your AAC frames each begin with an ADTS header, simply save as .aac to play later using some audio payer code.
I have researched everything and the answer is NO. There is no decoder in mp4/mp4v2 libraries. One has to use some other library to do that.
I need help in my iphone application, I want to convert byte array or binary data into audio file.Please help me out and tell me any way so i con do it.
If your array is supposed to contain audio data in PCM format, than you can simply add WAVE header at the beginning to get ready to play audio file. Format of header is described here.
I want to use OpenAL to play music in an iOS game. The music files are stored in mp3 format and I want to stream them using a buffer queue. I load audio data into the buffers using AudioFileReadPacketData(). However playing the buffers only gives me noise. It works perfectly for caf files, but not for mp3s. Did I miss some vital step in decoding the file?
Code I use to open the sound file:
- (void) openFile:(NSString*)fileName {
NSBundle *bundle = [NSBundle mainBundle];
CFURLRef url = (CFURLRef)[[NSURL fileURLWithPath:[bundle pathForResource:fileName ofType:#"mp3"]] retain];
AudioFileOpenURL(url, kAudioFileReadPermission, 0, &audioFile);
AudioStreamBasicDescription theFormat;
UInt32 formatSize = sizeof(theFormat);
AudioFileGetProperty(audioFile, kAudioFilePropertyDataFormat, &formatSize, &theFormat);
freq = (ALsizei)theFormat.mSampleRate;
CFRelease(url);
}
Code I use to fill in buffers:
- (void) loadOneChunkIntoBuffer:(ALuint)buffer {
char data[STREAM_BUFFER_SIZE];
UInt32 loadSize = STREAM_BUFFER_SIZE;
AudioStreamPacketDescription packetDesc[STREAM_PACKETS];
UInt32 numPackets = STREAM_PACKETS;
AudioFileReadPacketData(audioFile, NO, &loadSize, packetDesc, packetsLoaded, &numPackets, data);
alBufferData(buffer, AL_FORMAT_STEREO16, data, loadSize, freq);
packetsLoaded += numPackets;
}
Because you're reading bytes of MP3 data and treating them as PCM data.
You almost certainly want AudioFileReadPacketData(). EDIT: Except that still gives you MP3 data; it just gives it in packets and (possibly) parses packet headers.
If you don't require OpenAL, AVAudioPlayer is probably the better way to go (according to the Multimedia Programming Guide, there's also Audio Queue services if you want more control).
If you really need to use OpenAL, according to TN2199 you'll need to convert it to PCM in the native byte order. See oalTouch/Classes/MyOpenALSupport.c for an example of using Extended Audio File Services to do this. Note that TN2199 says the format "must ... not use hardware decompression" — according to the Multimedia Programming Guide, software decoding is supported for everything except HE-AAC since OS 3.0. Also note that software MP3 decoding can use a significant amount of CPU time.
Alternatively, explicitly convert the audio using AudioConverter or (possibly) AudioUnit with kAudioUnitSubType_AUConverter. If you do this, it might be worthwhile decompressing everything once and keeping it in memory to minimize overhead.