I need an audio steganalysis tool for detecting stego mp3 files.
There is an audio steganalysis tools (MP3stego), but its input is for wav stego files. Also there are some audio steganalysis algorithms that refers to MP3stego.
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I am recording audio from HTML and it is getting stored as .webm format.
I feeding that audio to google speech api to get the transcript from it.
I found out that .flac is lossless so I converted it from webm to flac using FFMPEG.
But i am having one doubt, converting audio from webm to flac increases the size of file but if an audio is already lossy with webm format converting to flac will still be lossy because the information is already lost.
Am i wrong with this assumption ?
Am i wrong with this assumption ?
No. FLAC conversion will only preserve the data in the source file. Any data lost during original conversion to WebM codec (Opus/vorbis) is gone.
I'm looking to convert some audio files into spectrograms. I'm wondering what the difference is between an m4a and wav file. If I have two of the same audio recording, one saved as wav and the other as m4a, will there be a difference in the spectrogram representations of both?
Both WAV and M4A are container formats, with options for how exactly audio data is encoded and represented inside the file. WAV file has one audio track with variety of encoding options including those possible for M4A format. However most often typically WAV refers to having uncompressed audio inside, where data is contained in PCM format.
M4A files are MP4 (MPEG-4 Part 14) files with an implication that there is one audio track inside. There are much less encoding options even though they still include both compressed and uncompressed ones. Most often M4A has audio encoded with AAC encoding, which is a lossy encoding. Depending on that loss, roughly on how much of information was lost during the encoding, your spectrogram could be different from the one built on original data.
The m4a format uses a lossy compression algorithm, so there may be differences, depending on compression level, and the resolution and depth of the spectrogram. The .wav format can also be lossy, due to quantization of the sound by an A/D or any sample format/rate conversions. So the difference may be in the noise floor, or in the portions of the sound's spectrum that are usually inaudible (due to masking effects and etc.) to humans.
How can I use ffmpeg and only extract the frames that does not have artifacts (e.g. compression artifacts) from a video and save them with good quality in jpeg format .
i need the audio file for the yuv test video sequences like foreman.yuv, akiyo.yuv
,etc. none of the yuv sequences online have the audio file.
any other yuv sequences with the audio file suitable for encoder analysis also works.
I think there is no audio available for the sequences you mention.
But have a look at https://media.xiph.org/video/derf/, at the bottom of the page you have full sequences with flac audio.
I am writing an encoding software and dealing with uncompressed wav and flac formats. My question is, flac is supposed to be a lossless format, similar to wav but compressed. However, certain softwares such as JRiver's Media Center offer a 'quality' setting for encoding flac files. Does taht mean they are offering to reduce quality pre-encoding or am i missing something in the flac standard?
The quality parameter for FLAC refers to the quality of compression, not audio. The audio will stay lossless but you get a better compression with higher quality. Higher quality will take more time to compress however.
See docs http://wiki.jriver.com/index.php/Encoding_Settings
Free Lossless Audio Codec (FLAC): FLAC is a popular lossless, freely
available open source encoder. [2] Quality Settings: 0 - 8. Sets the
quality of compression (and not sound, which is lossless), 8 meaning
most compressed/time/effort.