codec

I am aware that JPEG compression is lossy. I have 2 questions: Given an operation T: 1. Take a JPEG-80 image 2. Decode it to a byte buffer 3. Encode given byte buffer as JPEG-80 Is T an idempotent operation in terms of visual quality? Or will the quality of the image keep degrading as I repeat T? Does the same hold true for the JPEG-XR codec? Thank you! Edit : Since there have been conflicting answers, it would be great if you could provide references! It's not guaranteed, but it may happen. Especially if you repeat the encode -> decode -> encode -> decode process enough times, it will

I am trying to find the codec used to compress a movie. I am sure if I need to somehow use CMFormatDescription and get a CMVideoCodecType key. I am stuck as to how to get past the metadata array. Any ideas on how to retrieve the codec? AVURLAsset* movieAsset = [AVURLAsset URLAssetWithURL:sourceMovieURL options:nil]; NSArray *tracks = [movieAsset tracksWithMediaType:AVMediaTypeVideo]; if ([tracks count] != 0) { AVAssetTrack *videoTrack = [tracks objectAtIndex:0]; // // Let's get the movie's meta data // // Find the codec NSArray *metadata = [movieAsset commonMetadata]; } A Swift approach to

I need to use HTML 5 audio to play sounds. However, the codec support is very irritating: Firefox: Ogg, Wav Safari: Mp3, Wav Chrome: Ogg, Mp3 Opera: Wav I basically need to encode in Wav and Ogg/Mp3. However, Wav's are terrible in size and that is very crucial point for me. So, I guess I should go for Mp3 + Ogg leaving Opera and IE out? According to: http://my.opera.com/core/blog/2009/12/31/re-introducing-video , Opera 10.5 (still in alpha/beta) supports Vorbis and PCM Wav for audio. I don't believe 10.10 actually supports the audio tag. Safari would support Vorbis (and Theora on the video

I am trying to record video from the back camera (the one that faces the face) on my Samsung Galaxy S6 (which supports 1920x1080 at about 30 fps). I do not want to have to use any surface for previewing if I do not have to as this is to just happen in the background. I seem to have it working, but the output files are not playable in a way that actually is correct. On my Windows 10 PC, Windows Media Player will show the first frame and then play the audio, VLC will not show any of the frames. On my phone, the recorded file is playable but not totally. It will hold the first frame for 5-8

I am designing an app that can record short audio files on iPhone and Android that can be played back on both platforms, as well as hopefully any other smartphone. Right now I'm using *.caf with the iLBC codec, as I know the iPhone does not encode mp3. Is there a file format/codec that I should use in this case? It used to be that there were no common audio encoding formats for Android and iPhone. iPhone: iPhone audio encoding supported formats Android: Android supported media formats But Android 2.3.3 adds support for AMR-WB and AAC: Android Audio Encoder AAC See Media Framework at Android 2