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Diffstat (limited to 'Doc/lib/libaudioop.tex')
| -rw-r--r-- | Doc/lib/libaudioop.tex | 50 |
1 files changed, 25 insertions, 25 deletions
diff --git a/Doc/lib/libaudioop.tex b/Doc/lib/libaudioop.tex index 69a3a83..887cac9 100644 --- a/Doc/lib/libaudioop.tex +++ b/Doc/lib/libaudioop.tex @@ -19,46 +19,46 @@ This exception is raised on all errors, such as unknown number of bytes per sample, etc. \end{excdesc} -\begin{funcdesc}{add}{fragment1\, fragment2\, width} +\begin{funcdesc}{add}{fragment1, fragment2, width} Return a fragment which is the addition of the two samples passed as parameters. \var{width} is the sample width in bytes, either \code{1}, \code{2} or \code{4}. Both fragments should have the same length. \end{funcdesc} -\begin{funcdesc}{adpcm2lin}{adpcmfragment\, width\, state} +\begin{funcdesc}{adpcm2lin}{adpcmfragment, width, state} Decode an Intel/DVI ADPCM coded fragment to a linear fragment. See the description of \code{lin2adpcm} for details on ADPCM coding. Return a tuple \code{(\var{sample}, \var{newstate})} where the sample has the width specified in \var{width}. \end{funcdesc} -\begin{funcdesc}{adpcm32lin}{adpcmfragment\, width\, state} +\begin{funcdesc}{adpcm32lin}{adpcmfragment, width, state} Decode an alternative 3-bit ADPCM code. See \code{lin2adpcm3} for details. \end{funcdesc} -\begin{funcdesc}{avg}{fragment\, width} +\begin{funcdesc}{avg}{fragment, width} Return the average over all samples in the fragment. \end{funcdesc} -\begin{funcdesc}{avgpp}{fragment\, width} +\begin{funcdesc}{avgpp}{fragment, width} Return the average peak-peak value over all samples in the fragment. No filtering is done, so the usefulness of this routine is questionable. \end{funcdesc} -\begin{funcdesc}{bias}{fragment\, width\, bias} +\begin{funcdesc}{bias}{fragment, width, bias} Return a fragment that is the original fragment with a bias added to each sample. \end{funcdesc} -\begin{funcdesc}{cross}{fragment\, width} +\begin{funcdesc}{cross}{fragment, width} Return the number of zero crossings in the fragment passed as an argument. \end{funcdesc} -\begin{funcdesc}{findfactor}{fragment\, reference} +\begin{funcdesc}{findfactor}{fragment, reference} Return a factor \var{F} such that \code{rms(add(fragment, mul(reference, -F)))} is minimal, i.e., return the factor with which you should multiply \var{reference} to @@ -68,7 +68,7 @@ should both contain 2-byte samples. The time taken by this routine is proportional to \code{len(fragment)}. \end{funcdesc} -\begin{funcdesc}{findfit}{fragment\, reference} +\begin{funcdesc}{findfit}{fragment, reference} This routine (which only accepts 2-byte sample fragments) Try to match \var{reference} as well as possible to a portion of @@ -82,7 +82,7 @@ and \var{factor} is the (floating-point) factor as per \code{findfactor}. \end{funcdesc} -\begin{funcdesc}{findmax}{fragment\, length} +\begin{funcdesc}{findmax}{fragment, length} Search \var{fragment} for a slice of length \var{length} samples (not bytes!)\ with maximum energy, i.e., return \var{i} for which \code{rms(fragment[i*2:(i+length)*2])} is maximal. The fragments @@ -91,15 +91,15 @@ should both contain 2-byte samples. The routine takes time proportional to \code{len(fragment)}. \end{funcdesc} -\begin{funcdesc}{getsample}{fragment\, width\, index} +\begin{funcdesc}{getsample}{fragment, width, index} Return the value of sample \var{index} from the fragment. \end{funcdesc} -\begin{funcdesc}{lin2lin}{fragment\, width\, newwidth} +\begin{funcdesc}{lin2lin}{fragment, width, newwidth} Convert samples between 1-, 2- and 4-byte formats. \end{funcdesc} -\begin{funcdesc}{lin2adpcm}{fragment\, width\, state} +\begin{funcdesc}{lin2adpcm}{fragment, width, state} Convert samples to 4 bit Intel/DVI ADPCM encoding. ADPCM coding is an adaptive coding scheme, whereby each 4 bit number is the difference between one sample and the next, divided by a (varying) step. The @@ -113,41 +113,41 @@ initial call \code{None} can be passed as the state. \var{adpcmfrag} is the ADPCM coded fragment packed 2 4-bit values per byte. \end{funcdesc} -\begin{funcdesc}{lin2adpcm3}{fragment\, width\, state} +\begin{funcdesc}{lin2adpcm3}{fragment, width, state} This is an alternative ADPCM coder that uses only 3 bits per sample. It is not compatible with the Intel/DVI ADPCM coder and its output is not packed (due to laziness on the side of the author). Its use is discouraged. \end{funcdesc} -\begin{funcdesc}{lin2ulaw}{fragment\, width} +\begin{funcdesc}{lin2ulaw}{fragment, width} Convert samples in the audio fragment to U-LAW encoding and return this as a Python string. U-LAW is an audio encoding format whereby you get a dynamic range of about 14 bits using only 8 bit samples. It is used by the Sun audio hardware, among others. \end{funcdesc} -\begin{funcdesc}{minmax}{fragment\, width} +\begin{funcdesc}{minmax}{fragment, width} Return a tuple consisting of the minimum and maximum values of all samples in the sound fragment. \end{funcdesc} -\begin{funcdesc}{max}{fragment\, width} +\begin{funcdesc}{max}{fragment, width} Return the maximum of the \emph{absolute value} of all samples in a fragment. \end{funcdesc} -\begin{funcdesc}{maxpp}{fragment\, width} +\begin{funcdesc}{maxpp}{fragment, width} Return the maximum peak-peak value in the sound fragment. \end{funcdesc} -\begin{funcdesc}{mul}{fragment\, width\, factor} +\begin{funcdesc}{mul}{fragment, width, factor} Return a fragment that has all samples in the original framgent multiplied by the floating-point value \var{factor}. Overflow is silently ignored. \end{funcdesc} -\begin{funcdesc}{ratecv}{fragment\, width\, nchannels\, inrate\, outrate\, state\optional{\, weightA\, weightB}} +\begin{funcdesc}{ratecv}{fragment, width, nchannels, inrate, outrate, state\optional{, weightA, weightB}} Convert the frame rate of the input fragment. \code{State} is a tuple containing the state of the converter. The @@ -158,11 +158,11 @@ The \code{weightA} and \code{weightB} arguments are parameters for a simple digital filter and default to 1 and 0 respectively. \end{funcdesc} -\begin{funcdesc}{reverse}{fragment\, width} +\begin{funcdesc}{reverse}{fragment, width} Reverse the samples in a fragment and returns the modified fragment. \end{funcdesc} -\begin{funcdesc}{rms}{fragment\, width} +\begin{funcdesc}{rms}{fragment, width} Return the root-mean-square of the fragment, i.e. \iftexi the square root of the quotient of the sum of all squared sample value, @@ -177,20 +177,20 @@ divided by the sumber of samples. This is a measure of the power in an audio signal. \end{funcdesc} -\begin{funcdesc}{tomono}{fragment\, width\, lfactor\, rfactor} +\begin{funcdesc}{tomono}{fragment, width, lfactor, rfactor} Convert a stereo fragment to a mono fragment. The left channel is multiplied by \var{lfactor} and the right channel by \var{rfactor} before adding the two channels to give a mono signal. \end{funcdesc} -\begin{funcdesc}{tostereo}{fragment\, width\, lfactor\, rfactor} +\begin{funcdesc}{tostereo}{fragment, width, lfactor, rfactor} Generate a stereo fragment from a mono fragment. Each pair of samples in the stereo fragment are computed from the mono sample, whereby left channel samples are multiplied by \var{lfactor} and right channel samples by \var{rfactor}. \end{funcdesc} -\begin{funcdesc}{ulaw2lin}{fragment\, width} +\begin{funcdesc}{ulaw2lin}{fragment, width} Convert sound fragments in ULAW encoding to linearly encoded sound fragments. ULAW encoding always uses 8 bits samples, so \var{width} refers only to the sample width of the output fragment here. |