stft2.m
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1 function y = stft2(x, w, N, H)
2 % Analysis/synthesis of a sound using the short-time fourier transform
3 % x: input sound, w: analysis window (odd size), N: FFT size, H: hop size
4 % y: output sound
5 M = length(w); % analysis window size
6 N2 = N/2+1; % size of positive spectrum
7 soundlength = length(x); % length of input sound array
8 hM = (M-1)/2; % half analysis window size
9 pin = 1+hM; % initialize sound pointer in middle of analysis window
10 pend = soundlength-hM; % last sample to start a frame
11 fftbuffer = zeros(N,1); % initialize buffer for FFT
12 yw = zeros(M,1); % initialize output sound frame
13 y = zeros(soundlength,1); % initialize output array
14 w = w/sum(w); % normalize analysis window
15 while pin<pend
16 %-----analysis-----%
17 xw = x(pin-hM:pin+hM).*w(1:M); % window the input sound
18 fftbuffer(:) = 0; % reset buffer
19 fftbuffer(1:(M+1)/2) = xw((M+1)/2:M); % zero-phase window in fftbuffer
20 fftbuffer(N-(M-1)/2+1:N) = xw(1:(M-1)/2);
21 X = fft(fftbuffer); % compute FFT
22 mX = 20*log10(abs(X(1:N2))); % magnitude spectrum of positive frequencies
23 pX = unwrap(angle(X(1:N2))); % unwrapped phase spect. of positive freq.
24 %-----synthesis-----%
25 Y = zeros(N,1); % initialize output spectrum
26 Y(1:N2) = 10.^(mX/20).*exp(i.*pX); % generate positive freq.
27 Y(N2+1:N) = 10.^(mX(N2-1:-1:2)/20).*exp(-i.*pX(N2-1:-1:2));
28 % generate neg.freq.
29 fftbuffer = real(ifft(Y)); % inverse FFT
30 yw(1:(M-1)/2) = fftbuffer(N-(M-1)/2+1:N); % undo zero-phase window
31 yw((M+1)/2:M) = fftbuffer(1:(M+1)/2);
32 y(pin-hM:pin+hM) = y(pin-hM:pin+hM) + H*yw(1:M); % overlap-add
33 pin = pin+H; % advance sound pointer
34 end
start
Definition: start.py:1
pX
magnitude spectrum pX
Definition: stft_peak.m:24
in
About Git write you should know how to use GIT properly Luckily Git comes with excellent documentation git help man git shows you the available git< command > help man git< command > shows information about the subcommand< command > The most comprehensive manual is the website Git Reference visit they are quite exhaustive You do not need a special username or password All you need is to provide a ssh public key to the Git server admin What follows now is a basic introduction to Git and some FFmpeg specific guidelines Read it at least if you are granted commit privileges to the FFmpeg project you are expected to be familiar with these rules I if not You can get git from etc no matter how small Every one of them has been saved from looking like a fool by this many times It s very easy for stray debug output or cosmetic modifications to slip in
Definition: git-howto.txt:5
zeros
N, 1 zeros()
synthesis
FFT size for synthesis(even) H
N
function N
Definition: stft2.m:1
sample
#define sample
Definition: flacdsp_template.c:44
mX
FFT of current buffer mX
Definition: stft_peak.m:23
reset
About Git write you should know how to use GIT properly Luckily Git comes with excellent documentation git help man git shows you the available git< command > help man git< command > shows information about the subcommand< command > The most comprehensive manual is the website Git Reference visit they are quite exhaustive You do not need a special username or password All you need is to provide a ssh public key to the Git server admin What follows now is a basic introduction to Git and some FFmpeg specific guidelines Read it at least if you are granted commit privileges to the FFmpeg project you are expected to be familiar with these rules I if not You can get git from etc no matter how small Every one of them has been saved from looking like a fool by this many times It s very easy for stray debug output or cosmetic modifications to slip please avoid problems through this extra level of scrutiny For cosmetics only commits you should e g by running git config global user name My Name git config global user email my email which is either set in your personal configuration file through git config core editor or set by one of the following environment VISUAL or EDITOR Log messages should be concise but descriptive Explain why you made a what you did will be obvious from the changes themselves most of the time Saying just bug fix or is bad Remember that people of varying skill levels look at and educate themselves while reading through your code Don t include filenames in log Git provides that information Possibly make the commit message have a descriptive first an empty line and then a full description The first line will be used to name the patch by git format patch Renaming moving copying files or contents of making those normal commits mv cp path file otherpath otherfile git add[-A] git commit Do not rename or copy files of which you are not the maintainer without discussing it on the mailing list first Reverting broken commits git revert< commit > git revert will generate a revert commit This will not make the faulty commit disappear from the history git reset< commit > git reset will uncommit the changes till< commit > rewriting the current branch history git commit amend allows to amend the last commit details quickly git rebase i origin master will replay local commits over the main repository allowing to merge or remove some of them in the process Note that the reset
Definition: git-howto.txt:153
M
#define M(a, b)
Definition: vp3dsp.c:43
Y
#define Y
Definition: vf_boxblur.c:76
end
end end
Definition: extra/f0detection.m:15
magnitude
Plot spectral magnitude
Definition: FFT of a Simple Sinusoid.m:26
pend
initialize sound pointer in middle of analysis window pend
Definition: stft2.m:10
w
function w
Definition: stft2.m:1
frame
frame
Definition: stft.m:14
x
Discrete Time axis x
Definition: FFT of a Simple Sinusoid.m:10
y
function y
Definition: stft2.m:1
zero
#define zero
Definition: regdef.h:64
soundlength
size of positive spectrum soundlength
Definition: stft2.m:7
input
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several the filter must be ready for frames arriving randomly on any input any filter with several inputs will most likely require some kind of queuing mechanism It is perfectly acceptable to have a limited queue and to drop frames when the inputs are too unbalanced request_frame This method is called when a frame is wanted on an output For an input
Definition: filter_design.txt:216
spectrum
phase spectrum(unwrapped) ploc
window
overlapping window(triangular window to avoid too much overlapping) ovidx
size
int size
Definition: twinvq_data.h:11127
X
Sampled sinusoid X
Definition: FFT of a Simple Sinusoid.m:11
sound
sound(x3, Fs)
exp
1i.*Xphase exp()
pin
half analysis window size pin
Definition: stft2.m:9
yw
initialize buffer for FFT yw
Definition: stft2.m:12
i
synthesis window for stochastic i
Definition: code Kat/hpsmodel.m:34
fft
fftbuffer, N fft()
H
function H
Definition: stft2.m:1
to
FFmpeg Automated Testing Environment ************************************Table of Contents *****************FFmpeg Automated Testing Environment Introduction Using FATE from your FFmpeg source directory Submitting the results to the FFmpeg result aggregation server FATE makefile targets and variables Makefile targets Makefile variables Examples Introduction **************FATE is an extended regression suite on the client side and a means for results aggregation and presentation on the server side The first part of this document explains how you can use FATE from your FFmpeg source directory to test your ffmpeg binary The second part describes how you can run FATE to submit the results to FFmpeg s FATE server In any way you can have a look at the publicly viewable FATE results by visiting this as it can be seen if some test on some platform broke with their recent contribution This usually happens on the platforms the developers could not test on The second part of this document describes how you can run FATE to submit your results to FFmpeg s FATE server If you want to submit your results be sure to check that your combination of OS and compiler is not already listed on the above mentioned website In the third part you can find a comprehensive listing of FATE makefile targets and variables Using FATE from your FFmpeg source directory **********************************************If you want to run FATE on your machine you need to have the samples in place You can get the samples via the build target fate rsync Use this command from the top level source this will cause FATE to fail NOTE To use a custom wrapper to run the pass target exec to configure or set the TARGET_EXEC Make variable Submitting the results to the FFmpeg result aggregation server ****************************************************************To submit your results to the server you should run fate through the shell script tests fate sh from the FFmpeg sources This script needs to be invoked with a configuration file as its first argument tests fate sh path to fate_config A configuration file template with comments describing the individual configuration variables can be found at doc fate_config sh template Create a configuration that suits your based on the configuration template The slot configuration variable can be any string that is not yet but it is suggested that you name it adhering to the following pattern< arch >< os >< compiler >< compiler version > The configuration file itself will be sourced in a shell therefore all shell features may be used This enables you to setup the environment as you need it for your build For your first test runs the fate_recv variable should be empty or commented out This will run everything as normal except that it will omit the submission of the results to the server The following files should be present in $workdir as specified in the configuration it may help to try out the ssh command with one or more v options You should get detailed output concerning your SSH configuration and the authentication process The only thing left is to automate the execution of the fate sh script and the synchronisation of the samples directory FATE makefile targets and variables *************************************Makefile can be set to
Definition: fate.txt:142
hM
length of input sound array hM
Definition: stft2.m:8
xw
1:W2 xw()
buffer
the buffer and buffer reference mechanism is intended to as much as expensive copies of that data while still allowing the filters to produce correct results The data is stored in buffers represented by AVFilterBuffer structures They must not be accessed but through references stored in AVFilterBufferRef structures Several references can point to the same buffer
Definition: filter_design.txt:45
output
these buffered frames must be flushed immediately if a new input produces new output(Example:frame rate-doubling filter:filter_frame must(1) flush the second copy of the previous frame, if it is still there,(2) push the first copy of the incoming frame,(3) keep the second copy for later.) If the input frame is not enough to produce output
inverse
static uint32_t inverse(uint32_t v)
find multiplicative inverse modulo 2 ^ 32
Definition: asfcrypt.c:35
length
const char int length
Definition: avisynth_c.h:668
N2
analysis window size N2
Definition: stft2.m:6
fftbuffer
last sample to start a frame fftbuffer
Definition: stft2.m:11
a
a
Definition: h264pred_template.c:466
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