2014/10/15 下午 10:03:28

iphone Programming Glossary: aac

Writing video + generated audio to AVAssetWriterInput, audio stuttering

http://stackoverflow.com/questions/12187124/writing-video-generated-audio-to-avassetwriterinput-audio-stuttering

nil audioOutputSettings NSDictionary dictionaryWithObjectsAndKeys NSNumber numberWithInt kAudioFormatMPEG4AAC AVFormatIDKey NSNumber numberWithInt 2 AVNumberOfChannelsKey NSNumber numberWithFloat 44100.0 AVSampleRateKey NSNumber.. Any ideas on what's going on Should I be creating appending samples in a different way Is it something to do with the AAC compression It doesn't work if I try to use uncompressed audio it throws . As far as I can tell I'm calculating the PTS.. Update I've tried providing the audio in fixed blocks of 1024 samples since this is the size of the DCT used by the AAC compressor. Doesn't make any difference. I've tried pushing all the blocks in one go before writing any video. Doesn't work...

iPhone - convert mp3 to wav?

http://stackoverflow.com/questions/1478030/iphone-convert-mp3-to-wav

write a file . Note that a given converter cannot convert between two encoded formats you can do MP3 to PCM or PCM to AAC but to do MP3 to AAC you'd need two converters. Extended Audio File Services which combine both of the above. Check out.. that a given converter cannot convert between two encoded formats you can do MP3 to PCM or PCM to AAC but to do MP3 to AAC you'd need two converters. Extended Audio File Services which combine both of the above. Check out the ConvertFile example..

Video file formats supported in iPhone

http://stackoverflow.com/questions/1535836/video-file-formats-supported-in-iphone

video up to 1.5 Mbps 640 by 480 pixels 30 frames per second Low Complexity version of the H.264 Baseline Profile with AAC LC audio up to 160 Kbps 48kHz stereo audio in .m4v .mp4 and .mov file formats H.264 video up to 768 Kbps 320 by 240 pixels.. file formats H.264 video up to 768 Kbps 320 by 240 pixels 30 frames per second Baseline Profile up to Level 1.3 with AAC LC audio up to 160 Kbps 48kHz stereo audio in .m4v .mp4 and .mov file formats MPEG 4 video up to 2.5 Mbps 640 by 480 pixels.. .m4v .mp4 and .mov file formats MPEG 4 video up to 2.5 Mbps 640 by 480 pixels 30 frames per second Simple Profile with AAC LC audio up to 160 Kbps 48kHz stereo audio in .m4v .mp4 and .mov file formats Numerous audio formats including the ones..

MPMoviePlayerController & .m3u8 playlist

http://stackoverflow.com/questions/1665151/mpmovieplayercontroller-m3u8-playlist

audio and video despite the fact that the transport stream is part of the MPEG 2 spec the contents should be H.264 and AAC the audio and video codecs usually associated with MPEG 4 . You sometimes see other contents like .aac for audio only streams...

Supported Audio file formats in iPhone

http://stackoverflow.com/questions/1761460/supported-audio-file-formats-in-iphone

Library Audio Playback and Recording Formats The audio playback formats supported in iPhone OS are the following AAC HE AAC AMR Adaptive Multi Rate a format for speech ALAC Apple Lossless iLBC internet Low Bitrate Codec another format for.. Audio Playback and Recording Formats The audio playback formats supported in iPhone OS are the following AAC HE AAC AMR Adaptive Multi Rate a format for speech ALAC Apple Lossless iLBC internet Low Bitrate Codec another format for speech.. 繕 law and a law MP3 MPEG 1 audio layer 3 The audio recording formats supported in iPhone OS are the following AAC on supported devices only ALAC Apple Lossless iLBC internet Low Bitrate Codec for speech IMA4 IMA ADPCM linear PCM 繕 law..

What video formats are compatible with the assets library?

http://stackoverflow.com/questions/3257224/what-video-formats-are-compatible-with-the-assets-library

bit little endian signed integer 48000 Hz Stereo L R 35.33 Mbit s 6119419764_hd.mp4 AVC Coding 1 280 x 720 NO YES YES AAC 44100 Hz Stereo L R 2.15 Mbit s 6119419764_site.mp4 AVC Coding 640 x 360 NO YES YES AAC 44100 Hz Stereo L R 833.71 kbit.. Coding 1 280 x 720 NO YES YES AAC 44100 Hz Stereo L R 2.15 Mbit s 6119419764_site.mp4 AVC Coding 640 x 360 NO YES YES AAC 44100 Hz Stereo L R 833.71 kbit s 6119419764_mobile.mp4 AVC Coding 568 x 320 YES YES YES AAC 32000 Hz Mono 775.14 kbit s.. 640 x 360 NO YES YES AAC 44100 Hz Stereo L R 833.71 kbit s 6119419764_mobile.mp4 AVC Coding 568 x 320 YES YES YES AAC 32000 Hz Mono 775.14 kbit s 6121206003_orig.mov Taken with iPhone 3Gs H.264 480 x 360 YES YES YES AAC 44100 Hz Mono 865.94..

merge Audio files on iPhone

http://stackoverflow.com/questions/3359313/merge-audio-files-on-iphone

2 mp3 sounds at the same time in iphone?

http://stackoverflow.com/questions/5026105/2-mp3-sounds-at-the-same-time-in-iphone

function. The following limitations pertain for simultaneous sounds in iPhone OS depending on the audio data format AAC MP3 and ALAC Apple Lossless audio You may play multiple AAC MP3 and ALAC format sounds simultaneously playback of multiple.. sounds in iPhone OS depending on the audio data format AAC MP3 and ALAC Apple Lossless audio You may play multiple AAC MP3 and ALAC format sounds simultaneously playback of multiple sounds of these formats will require CPU resources for decoding...

Realtime Audio/Video Streaming FROM iPhone to another device (Browser, or iPhone)

http://stackoverflow.com/questions/5719538/realtime-audio-video-streaming-from-iphone-to-another-device-browser-or-iphone

raw data and use FFmpeg to encode on the phone will use a ton of CPU and battery . Write your own parser for the H.264 AAC output very hard Record and process in chunks will add latency equal to the length of the chunks and drop around 1 4 second..

OGG Vorbis in iPhone sdk

http://stackoverflow.com/questions/4745618/ogg-vorbis-in-iphone-sdk

that have cropped up since then that it doesn't handle. Why do you need to play ogg files If you convert them to aac you will be able to play them back using hardware decoding which is much more efficient from a cpu usage point of view...

iOS and decoding MP3/AAC data from memory buffer

http://stackoverflow.com/questions/6691510/ios-and-decoding-mp3-aac-data-from-memory-buffer

there are some functions like ExtAudiofile... for decoding MP3 AAC files but are there any that will operate on Mp3 aac data that's already in memory I will probably have to extract the media data byte by byte iOS does allow that right from..

AudioQueue how to find out playback length of queued data

http://stackoverflow.com/questions/7375309/audioqueue-how-to-find-out-playback-length-of-queued-data

else if fileExtension isEqual @ caf fileTypeHint kAudioFileCAFType else if fileExtension isEqual @ aac fileTypeHint kAudioFileAAC_ADTSType return fileTypeHint id initWithURL NSURL url andFileType NSString ext self super init..

ExtAudioFileWrite to m4a/aac failing on dual-core devices (ipad 2, iphone 4s)

http://stackoverflow.com/questions/8719865/extaudiofilewrite-to-m4a-aac-failing-on-dual-core-devices-ipad-2-iphone-4s

to m4a aac failing on dual core devices ipad 2 iphone 4s I wrote a loop to encode pcm audio data generated by my app to aac using.. m4a aac failing on dual core devices ipad 2 iphone 4s I wrote a loop to encode pcm audio data generated by my app to aac using Extended Audio File Services. The encoding takes place in a background thread synchronously and not in real time... created but ExtAudioFileWrite fails the 2nd 3rd time it is called. Any ideas Thank you iphone ios ipad core audio aac share improve this question I had a very similar problem where I was attempting to use Extended Audio File Services..