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about G729 framing details

Started by renzhengshu3 in Speech Coding13 years ago 4 replies

HI, all I have a question on G729 framing details I used a G729 codec to encode a .wav file before encoding, it is about 300 KB ...

HI, all I have a question on G729 framing details I used a G729 codec to encode a .wav file before encoding, it is about 300 KB after encoding using G729 without VAD , the encoded G729 file is still about 300 KB, why isn't there any compression on bytes? after encoding using G729 with VAD, the encoded file is about 250KB, only 50 KB smaller? Besides, according to a pos...


question about linear prediction of the chirp

Started by Farzane Ahmadi in Speech Coding13 years ago

Hi I am trying to measure the resonances of an arbitrary cavity. I use an ultrasonic signal x to excite the cavity and try to estimate the...

Hi I am trying to measure the resonances of an arbitrary cavity. I use an ultrasonic signal x to excite the cavity and try to estimate the resonances from the cavity output (y). x --> [cavity] --> y I use a chirp pulse train as input (x) to excite the cavity. http://www.mathworks.com/help/toolbox/signal/chirp.html Chirp has a flat spectrum so in frequency domain it has a uniform freq


NB-AMR seek implementation

Started by Padmanabha V Reddy in Speech Coding13 years ago 3 replies

Hi, I am finding that after seek the output of NB-AMR decoder is distorted. I have observed this behavior with 1. codecs from Google (as...

Hi, I am finding that after seek the output of NB-AMR decoder is distorted. I have observed this behavior with 1. codecs from Google (as part Android), as well as 2. in PC based decoder called AMRPlayer software(For this, I have actually dumped the input given to Google's decoder and fed it to AMRPlayer, thereby I'm simulating the seek but not doing the seek even though it has it). ...


ITU-T G.723.1 Speech Coder: A Matlab Implementation P. Kabal Department of Electrical & Computer Engineering McGill University

Started by lu dinh vu in Speech Coding13 years ago 1 reply

In document: ITU-T G.723.1 Speech Coder: A Matlab Implementation P. Kabal Department of Electrical & Computer Engineering McGill...

In document: ITU-T G.723.1 Speech Coder: A Matlab Implementation P. Kabal Department of Electrical & Computer Engineering McGill University -------------------HHP(z), ---Highpass Filter ?(page 5).? and in page 15, what is HF(z)? tks! LU DINH VU


G722 Source Link

Started by mahesh_gb5 in Speech Coding14 years ago 1 reply

Dear All Please let me know where i can download the G722 source code if i use this is there any licensing issues. Thanks and reg's --Mahesh

Dear All Please let me know where i can download the G722 source code if i use this is there any licensing issues. Thanks and reg's --Mahesh


EVRC-B capable of word Mangling/ word replacement

Started by Kevin in Speech Coding14 years ago 1 reply

I came across a recording at the mobile of a land to mobile EVRC-B call Not on VZW. It had Screech Which was no surprise but also it decoded...

I came across a recording at the mobile of a land to mobile EVRC-B call Not on VZW. It had Screech Which was no surprise but also it decoded words that were not sent in the Harvard sentence source speech files! The word "write" was turned into ri.....ot and the word "cookie" became coochie! This would make it possible peoples words could be unknowingly miss understood or worse! Can 4GV mangl...


data format of PCM 16bit signed mono-channel and alignment(line-up) two PCM-16bit .wav files.

Started by nangergong in Speech Coding14 years ago 2 replies

Hi, all: I have some .wav files with format of PCM 16bit signed mono-channel from this...

Hi, all: I have some .wav files with format of PCM 16bit signed mono-channel from this link: https://ccrma.stanford.edu/courses/422/projects/WaveFormat/ I know each sample of these .wav files(except the header) can be converted to value -32768 to 32767 I want to time-align two .wav files with the format mentioned above. My steps are: 1) convert .wav files...


About PESQ scores(audio quality evaluation)

Started by nang...@gmail.com in Speech Coding14 years ago 2 replies

I have a question on PESQ If I want to verify the PESQ score of G711 and G729 codec, what procedures should I take? my idea is: 1)...

I have a question on PESQ If I want to verify the PESQ score of G711 and G729 codec, what procedures should I take? my idea is: 1) prepare a audio .wav file, whose format is PCM 8000Hz, signed 16 bit, let me name it ori.wav 2) encode it into G711 or G729 format and get enc.wav 3) convert enc.wav into PCM 8000Hz, signed 16 bit format, and I get deg.wav 4) run PESQ alg...


Re: how to input sound directly from a audioplayer(like windows media player) into

Started by Jeff Brower in Speech Coding14 years ago

Nangergong- > sorry, there is one place which is wrong in the illustration. The latter computer > is B not A. > > reference .wav...

Nangergong- > sorry, there is one place which is wrong in the illustration. The latter computer > is B not A. > > reference .wav file(signed 16bit, 8000Hz) ----> audio_player --------> VOIP program > on computer A -----------> network ----------------> VOIP program on computer B > -------------> audio recorder > ------------------------------ > > What is the point of the experiment? The d


Re: how to input sound directly from a audio player(like windows media player) into

Started by Jeff Brower in Speech Coding14 years ago

Nangergong- > I want to do an experiment > > reference .wav file(signed 16bit, 8000Hz) ----> audio_player > --------> VOIP program ...

Nangergong- > I want to do an experiment > > reference .wav file(signed 16bit, 8000Hz) ----> audio_player > --------> VOIP program on computer A -----------> network > ----------------> VOIP program on computer A > -------------> audio recorder > > when I use 'mixer' mode of recording device on Windows system > for transferring sound stream, the sound stream will be > processed b


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