Este post é uma tradução do post original anterior, Converting Audio Bit Depths in C#, em inglês
Sinais de áudio digitais podem ser armazenados em muitos tipos de formatos diferentes. Por exemplo, um sinal de áudio poderia ser armazenado como um sinal PCM de 16-bits dentro de um arquivo WAVE ou codificado em um formato com perdas como o MP3. Mas em todos os casos, todos sinais digitais são representados como uma sequência de valores, denominadas amostras, as quais são resultado da mensuração de uma determinada característica do som em função do tempo, para que possam ser manipuladas digitalmente.
Amostras (ou samples) formam um sinal discreto (digital) tipicamente originado de um sinal contínuo (analógico, como as ondas sonoras), obtido através de algum tipo de procedimento ou algorítmo de conversão (de amostragem). Assim existem, portanto, muitas maneiras de se representar uma amostra, como com bytes de 8-bits, inteiros de 32-bits ou números de ponto flutuante (floats) de 32-bits. E, por vezes, a conversão entre estes vários tipos de representações são um requerimento inicial em diversas aplicações.
Convertendo entre diferentes representações de amostras de áudio em C#
Para converter entre diferentes representações de amostras, além de modificar o tipo de dado (sua profundidade em bits) ainda é preciso adequar nossas amostras em uma nova escala. Por exemplo, para converter de um float de 32-bits para um unsigned byte de 8-bits, nós temos que transportar a amostra original de seu intervalo de [-1;1] para seu novo intervalo de [0;255].
Para realizar este processo, a classe a seguir contém um único (exaustivamente sobrecarregado) método que permite converter, por exemplo, amostras de 16-bit para 8-bit, 16-bit para float, float para 16-bit, entre outros. De fato, são possíveis conversões entre quaisquer um dos seguintes tipos: unsigned 8-bit bytes, signed 16-bit integers, signed 32-bit integers e 32-bit floating point single precision numbers. Espero que o código seguinte seja útil a alguem que esteja interessado!
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<span>namespace</span> cSouza.Audio { <span>using</span> System; <span>/// <summary></span> <span>/// Static methods to convert between different sample formats.</span> <span>/// </summary></span> <span>/// <remarks></span> <span>/// <para></span> <span>/// Code is mainly based on information available on the original</span> <span>/// C source code pa_converters.c from Portable Audio I/O Library.</span> <span>/// </para></span> <span>/// <para></span> <span>/// This class try to be as fast as possible without using unsafe code.</span> <span>/// </para></span> <span>/// <para></span> <span>/// Dither isn't currently supported. Currently supported conversions</span> <span>/// are 'to' and 'from' conversions between the following value types:</span> <span>/// </para></span> <span>/// <para></span> <span>/// Integer 8-bit (byte), </span> <span>/// Integer 16-bit (Int16), </span> <span>/// Integer 32-bit (Int32), </span> <span>/// Single precision 32-bit floating point (float).</span> <span>/// </para></span> <span>/// <para></span> <span>/// Which are the most common PCM formats.</span> <span>/// </para></span> <span>/// <example></span> <span>/// To use it, just call Convert. The compiler will automatically detect</span> <span>/// which method to call based on your data types. Couldn't be simplier.</span> <span>/// <code></span> <span>/// int[] srcPcm16samples = new int[] { 1, 2, 3};</span> <span>/// float[] destIeeeFloat32samples = new float[3];</span> <span>/// </span> <span>/// SampleConverter.Convert(srcPcm16samples, destIeeeFloat32samples);</span> <span>/// </span> <span>/// // destIeeeFloat32samples now contains the converted samples.</span> <span>/// </code></span> <span>/// </example></span> <span>/// </remarks></span> <span>public</span> <span>static</span> <span>class</span> SampleConverter { <span>#region</span> Consts: Standard values used <span>in</span> almost all conversions. <span>private</span> <span>const</span> <span>float</span> const_1_div_128_ = 1.0f / 128.0f; <span>// 8 bit multiplier</span> <span>private</span> <span>const</span> <span>float</span> const_1_div_32768_ = 1.0f / 32768.0f; <span>// 16 bit multiplier</span> <span>private</span> <span>const</span> <span>double</span> const_1_div_2147483648_ = 1.0 / 2147483648.0; <span>// 32 bit</span> <span>#endregion</span> <span>#region</span> From UInt8 (<span>byte</span>) <span>#region</span> From UInt8 (<span>byte</span>) to Int16 (<span>short</span>) <span>/// <summary></span> <span>/// Converts a array of signed 8-bit int samples</span> <span>/// into a array of 32-bit float-point samples.</span> <span>/// </summary></span> <span>/// <param name="from">The original sample.</param></span> <span>/// <param name="to">The resulting sample.</param></span> <span>public</span> <span>static</span> <span>void</span> Convert(<span>byte</span>[][] from, Int16[][] to) { <span>for</span> (<span>int</span> j = 0; j < from.Length; j++) <span>for</span> (<span>int</span> i = 0; i < from[0].Length; i++) to[i][j] = (Int16)((from[i][j] - 128) << 8); } <span>/// <summary></span> <span>/// Converts a array of signed 8-bit int samples</span> <span>/// into a array of 32-bit float-point samples.</span> <span>/// </summary></span> <span>/// <param name="from">The original sample.</param></span> <span>/// <param name="to">The resulting sample.</param></span> <span>public</span> <span>static</span> <span>void</span> Convert(<span>byte</span>[] from, Int16[] to) { <span>for</span> (<span>int</span> i = 0; i < from.Length; i++) to[i] = (Int16)((from[i] - 128) << 8); } <span>/// <summary></span> <span>/// Converts a signed 8-bit int sample</span> <span>/// into a 32-bit float-point sample.</span> <span>/// </summary></span> <span>/// <param name="from">The original sample.</param></span> <span>/// <param name="to">The resulting sample.</param></span> <span>public</span> <span>static</span> <span>void</span> Convert(<span>byte</span> from, <span>out</span> Int16 to) { to = (Int16)((from - 128) << 8); } <span>#endregion</span> <span>#region</span> From UInt8 (<span>byte</span>) to Int32 (<span>int</span>) <span>/// <summary></span> <span>/// Converts a matrix of unsigned 8-bit int samples</span> <span>/// into a matrix of 32-bit float-point samples.</span> <span>/// </summary></span> <span>/// <param name="from">The original sample.</param></span> <span>/// <param name="to">The resulting sample.</param></span> <span>public</span> <span>static</span> <span>void</span> Convert(<span>byte</span>[][] from, <span>int</span>[][] to) { <span>for</span> (<span>int</span> i = 0; i < from.Length; i++) <span>for</span> (<span>int</span> j = 0; j < from[0].Length; j++) to[i][j] = ((from[i][j] - 128) << 24); } <span>/// <summary></span> <span>/// Converts a array of unsigned 8-bit int samples</span> <span>/// into a array of 32-bit float-point samples.</span> <span>/// </summary></span> <span>/// <param name="from">The original sample.</param></span> <span>/// <param name="to">The resulting sample.</param></span> <span>public</span> <span>static</span> <span>void</span> Convert(<span>byte</span>[] from, <span>int</span>[] to) { <span>for</span> (<span>int</span> i = 0; i < from.Length; i++) to[i] = ((from[i] - 128) << 24); } <span>/// <summary></span> <span>/// Converts a unsigned 8-bit int sample</span> <span>/// into a 32-bit float-point sample.</span> <span>/// </summary></span> <span>/// <param name="from">The original sample.</param></span> <span>/// <param name="to">The resulting sample.</param></span> <span>public</span> <span>static</span> <span>void</span> Convert(<span>byte</span> from, <span>out</span> <span>int</span> to) { to = ((from - 128) << 24); } <span>#endregion</span> <span>#region</span> From UInt8 (<span>byte</span>) to Single (<span>float</span>) <span>/// <summary></span> <span>/// Converts a matrix of unsigned 8-bit int samples</span> <span>/// into a matrix of 32-bit float-point samples.</span> <span>/// </summary></span> <span>/// <param name="from">The original sample.</param></span> <span>/// <param name="to">The resulting sample.</param></span> <span>public</span> <span>static</span> <span>void</span> Convert(<span>byte</span>[][] from, <span>float</span>[][] to) { <span>for</span> (<span>int</span> i = 0; i < from.Length; i++) <span>for</span> (<span>int</span> j = 0; j < from[0].Length; j++) to[i][j] = (from[i][j] - 128) * const_1_div_128_; } <span>/// <summary></span> <span>/// Converts a array of unsigned 8-bit int samples</span> <span>/// into a array of 32-bit float-point samples.</span> <span>/// </summary></span> <span>/// <param name="from">The original sample.</param></span> <span>/// <param name="to">The resulting sample.</param></span> <span>public</span> <span>static</span> <span>void</span> Convert(<span>byte</span>[] from, <span>float</span>[] to) { <span>for</span> (<span>int</span> i = 0; i < from.Length; i++) to[i] = (from[i] - 128) * const_1_div_128_; } <span>/// <summary></span> <span>/// Converts a unsigned 8-bit int sample</span> <span>/// into a 32-bit float-point sample.</span> <span>/// </summary></span> <span>/// <param name="from">The original sample.</param></span> <span>/// <param name="to">The resulting sample.</param></span> <span>public</span> <span>static</span> <span>void</span> Convert(<span>byte</span> from, <span>out</span> <span>float</span> to) { to = (from - 128) * const_1_div_128_; } <span>#endregion</span> <span>#endregion</span> <span>#region</span> From Int16 (<span>short</span>) <span>#region</span> From Int16 (<span>short</span>) to UInt8 (<span>byte</span>) <span>/// <summary></span> <span>/// Converts a matrix of signed 16-bit int samples</span> <span>/// into a matrix of 8-bit unsigned byte samples.</span> <span>/// </summary></span> <span>/// <param name="from">The original sample.</param></span> <span>/// <param name="to">The resulting sample.</param></span> <span>public</span> <span>static</span> <span>void</span> Convert(Int16[][] from, <span>byte</span>[][] to) { <span>for</span> (<span>int</span> j = 0; j < from.Length; j++) <span>for</span> (<span>int</span> i = 0; i < from[i].Length; i++) to[i][j] = (<span>byte</span>)(((from[i][j]) >> 8) + 128); } <span>/// <summary></span> <span>/// Converts a array of signed 16-bit int samples</span> <span>/// into a array of 8-bit unsigned byte samples.</span> <span>/// </summary></span> <span>/// <param name="from">The original sample.</param></span> <span>/// <param name="to">The resulting sample.</param></span> <span>public</span> <span>static</span> <span>void</span> Convert(Int16[] from, <span>byte</span>[] to) { <span>for</span> (<span>int</span> i = 0; i < from.Length; i++) to[i] = (<span>byte</span>)(((from[i]) >> 8) + 128); } <span>/// <summary></span> <span>/// Converts a signed 16-bit int sample</span> <span>/// into a 8-bit unsigned byte sample.</span> <span>/// </summary></span> <span>/// <param name="from">The original sample.</param></span> <span>/// <param name="to">The resulting sample.</param></span> <span>public</span> <span>static</span> <span>void</span> Convert(Int16 from, <span>out</span> <span>byte</span> to) { to = (<span>byte</span>)(((from) >> 8) + 128); } <span>#endregion</span> <span>#region</span> From Int16 (<span>short</span>) to Int32 (<span>int</span>) <span>/// <summary></span> <span>/// Converts a matrix of signed 16-bit int samples</span> <span>/// into a matrix of 32-bit signed integer samples.</span> <span>/// </summary></span> <span>/// <param name="from">The original sample.</param></span> <span>/// <param name="to">The resulting sample.</param></span> <span>public</span> <span>static</span> <span>void</span> Convert(Int16[][] from, Int32[][] to) { <span>for</span> (<span>int</span> j = 0; j < from.Length; j++) <span>for</span> (<span>int</span> i = 0; i < from[i].Length; i++) to[i][j] = (<span>byte</span>)(((from[i][j]) >> 8) + 128); } <span>/// <summary></span> <span>/// Converts a array of signed 16-bit int samples</span> <span>/// into a array of 32-bit signed integer samples.</span> <span>/// </summary></span> <span>/// <param name="from">The original sample.</param></span> <span>/// <param name="to">The resulting sample.</param></span> <span>public</span> <span>static</span> <span>void</span> Convert(Int16[] from, Int32[] to) { <span>for</span> (<span>int</span> i = 0; i < from.Length; i++) to[i] = (<span>byte</span>)(((from[i]) >> 8) + 128); } <span>/// <summary></span> <span>/// Converts a signed 16-bit int sample</span> <span>/// into a 32-bit signed integer sample.</span> <span>/// </summary></span> <span>/// <param name="from">The original sample.</param></span> <span>/// <param name="to">The resulting sample.</param></span> <span>public</span> <span>static</span> <span>void</span> Convert(Int16 from, <span>out</span> Int32 to) { to = (<span>byte</span>)(((from) >> 8) + 128); } <span>#endregion</span> <span>#region</span> From Int16 (<span>short</span>) to Single (<span>float</span>) <span>/// <summary></span> <span>/// Converts a matrix of signed 16-bit int samples</span> <span>/// into a matrix of 32-bit float-point samples.</span> <span>/// </summary></span> <span>/// <param name="from">The original sample.</param></span> <span>/// <param name="to">The resulting sample.</param></span> <span>public</span> <span>static</span> <span>void</span> Convert(Int16[][] from, <span>float</span>[][] to) { <span>for</span> (<span>int</span> j = 0; j < from.Length; j++) <span>for</span> (<span>int</span> i = 0; i < from[i].Length; i++) to[i][j] = (<span>float</span>)(from[i][j]*const_1_div_32768_); } <span>/// <summary></span> <span>/// Converts a array of signed 16-bit int samples</span> <span>/// into a array of 32-bit float-point samples.</span> <span>/// </summary></span> <span>/// <param name="from">The original sample.</param></span> <span>/// <param name="to">The resulting sample.</param></span> <span>public</span> <span>static</span> <span>void</span> Convert(Int16[] from, <span>float</span>[] to) { <span>for</span> (<span>int</span> i = 0; i < from.Length; i++) to[i] = (<span>float</span>)(from[i]*const_1_div_32768_); } <span>/// <summary></span> <span>/// Converts a signed 16-bit int sample</span> <span>/// into a 32-bit float-point sample.</span> <span>/// </summary></span> <span>/// <param name="from">The original sample.</param></span> <span>/// <param name="to">The resulting sample.</param></span> <span>public</span> <span>static</span> <span>void</span> Convert(Int16 from, <span>out</span> <span>float</span> to) { to = (<span>float</span>)(from*const_1_div_32768_); } <span>#endregion</span> <span>#endregion</span> <span>#region</span> From Int32 (<span>int</span>) <span>#region</span> From Int32 (<span>int</span>) To UInt8 (<span>byte</span>) <span>/// <summary></span> <span>/// Converts a matrix of signed 32-bit int samples</span> <span>/// into a matrix of 8-bit unsigned byte samples.</span> <span>/// </summary></span> <span>/// <param name="from">The original sample.</param></span> <span>/// <param name="to">The resulting sample.</param></span> <span>public</span> <span>static</span> <span>void</span> Convert(Int32[][] from, <span>byte</span>[][] to) { <span>for</span> (<span>int</span> j = 0; j < from.Length; j++) <span>for</span> (<span>int</span> i = 0; i < from[i].Length; i++) to[i][j] = (<span>byte</span>)(((from[i][j]) >> 24) + 128); } <span>/// <summary></span> <span>/// Converts a array of signed 32-bit int samples</span> <span>/// into a array of 8-bit unsigned byte samples.</span> <span>/// </summary></span> <span>/// <param name="from">The original sample.</param></span> <span>/// <param name="to">The resulting sample.</param></span> <span>public</span> <span>static</span> <span>void</span> Convert(Int32[] from, <span>byte</span>[] to) { <span>for</span> (<span>int</span> i = 0; i < from.Length; i++) to[i] = (<span>byte</span>)(((from[i]) >> 24) + 128); } <span>/// <summary></span> <span>/// Converts a signed 32-bit int sample</span> <span>/// into a 8-bit unsigned byte sample.</span> <span>/// </summary></span> <span>/// <param name="from">The original sample.</param></span> <span>/// <param name="to">The resulting sample.</param></span> <span>public</span> <span>static</span> <span>void</span> Convert(Int32 from, <span>out</span> <span>byte</span> to) { to = (<span>byte</span>)((from >> 24) + 128); } <span>#endregion</span> <span>#region</span> From Int32 (<span>int</span>) to Int16 (<span>short</span>) <span>/// <summary></span> <span>/// Converts a matrix of signed 32-bit int samples</span> <span>/// into a matrix of 16-bit signed integer samples.</span> <span>/// </summary></span> <span>/// <param name="from">The original sample.</param></span> <span>/// <param name="to">The resulting sample.</param></span> <span>public</span> <span>static</span> <span>void</span> Convert(Int32[][] from, Int16[][] to) { <span>for</span> (<span>int</span> j = 0; j < from.Length; j++) <span>for</span> (<span>int</span> i = 0; i < from[i].Length; i++) to[i][j] = (Int16)(from[i][j] >> 16); } <span>/// <summary></span> <span>/// Converts a array of signed 32-bit int samples</span> <span>/// into a array of 16-bit signed integer samples.</span> <span>/// </summary></span> <span>/// <param name="from">The original sample.</param></span> <span>/// <param name="to">The resulting sample.</param></span> <span>public</span> <span>static</span> <span>void</span> Convert(Int32[] from, Int16[] to) { <span>for</span> (<span>int</span> i = 0; i < from.Length; i++) to[i] = (Int16)(from[i] >> 16); } <span>/// <summary></span> <span>/// Converts a signed 32-bit int sample</span> <span>/// into a 16-bit signed integer sample.</span> <span>/// </summary></span> <span>/// <param name="from">The original sample.</param></span> <span>/// <param name="to">The resulting sample.</param></span> <span>public</span> <span>static</span> <span>void</span> Convert(Int32 from, <span>out</span> Int16 to) { to = (Int16)(from >> 16); } <span>#endregion</span> <span>#region</span> From Int32 (<span>int</span>) to Single (<span>float</span>) <span>/// <summary></span> <span>/// Converts a matrix of signed 32-bit int samples</span> <span>/// into a matrix of 32-bit float-point samples.</span> <span>/// </summary></span> <span>/// <param name="from">The original sample.</param></span> <span>/// <param name="to">The resulting sample.</param></span> <span>public</span> <span>static</span> <span>void</span> Convert(Int32[][] from, <span>float</span>[][] to) { <span>for</span> (<span>int</span> j = 0; j < from.Length; j++) <span>for</span> (<span>int</span> i = 0; i < from[i].Length; i++) to[i][j] = (<span>float</span>)(from[i][j]*const_1_div_2147483648_); } <span>/// <summary></span> <span>/// Converts a array of signed 32-bit int samples</span> <span>/// into a array of 32-bit float-point samples.</span> <span>/// </summary></span> <span>/// <param name="from">The original sample.</param></span> <span>/// <param name="to">The resulting sample.</param></span> <span>public</span> <span>static</span> <span>void</span> Convert(Int32[] from, <span>float</span>[] to) { <span>for</span> (<span>int</span> i = 0; i < from.Length; i++) to[i] = (<span>float</span>)((<span>double</span>)from[i]*const_1_div_2147483648_); } <span>/// <summary></span> <span>/// Converts a signed 32-bit int sample</span> <span>/// into a 32-bit float-point sample.</span> <span>/// </summary></span> <span>/// <param name="from">The original sample.</param></span> <span>/// <param name="to">The resulting sample.</param></span> <span>public</span> <span>static</span> <span>void</span> Convert(Int32 from, <span>out</span> <span>float</span> to) { to = (<span>float</span>)((<span>double</span>)from*const_1_div_2147483648_); } <span>#endregion</span> <span>#endregion</span> <span>#region</span> From Single (<span>float</span>) <span>#region</span> From Single (<span>float</span>) to UInt8 (<span>byte</span>) <span>/// <summary></span> <span>/// Converts a matrix of signed 32-bit float samples</span> <span>/// into a matrix of 8-bit unsigned byte samples.</span> <span>/// </summary></span> <span>/// <param name="from">The original sample.</param></span> <span>/// <param name="to">The resulting sample.</param></span> <span>public</span> <span>static</span> <span>void</span> Convert(<span>float</span>[][] from, <span>byte</span>[][] to) { <span>for</span> (<span>int</span> j = 0; j < from.Length; j++) <span>for</span> (<span>int</span> i = 0; i < from[i].Length; i++) to[i][j] = (<span>byte</span>)(128 + ((<span>byte</span>)(to[i][j]*(127.0f)))); } <span>/// <summary></span> <span>/// Converts a array of signed 32-bit float samples</span> <span>/// into a array of 8-bit unsigned byte samples.</span> <span>/// </summary></span> <span>/// <param name="from">The original sample.</param></span> <span>/// <param name="to">The resulting sample.</param></span> <span>public</span> <span>static</span> <span>void</span> Convert(<span>float</span>[] from, <span>byte</span>[] to) { <span>for</span> (<span>int</span> i = 0; i < from.Length; i++) to[i] = (<span>byte</span>)(128 + ((<span>byte</span>)(to[i]*(127.0f)))); } <span>/// <summary></span> <span>/// Converts a signed 32-bit float sample</span> <span>/// into a 8-bit unsigned byte sample.</span> <span>/// </summary></span> <span>/// <param name="from">The original sample.</param></span> <span>/// <param name="to">The resulting sample.</param></span> <span>public</span> <span>static</span> <span>void</span> Convert(<span>float</span> from, <span>out</span> <span>byte</span> to) { to = (<span>byte</span>)(128 + ((<span>byte</span>)(from*(127.0f)))); } <span>#endregion</span> <span>#region</span> From Single (<span>float</span>) to Int16 (<span>short</span>) <span>/// <summary></span> <span>/// Converts a matrix of signed 32-bit float samples</span> <span>/// into a matrix of signed 16-bit integer samples.</span> <span>/// </summary></span> <span>/// <param name="from">The original sample.</param></span> <span>/// <param name="to">The resulting sample.</param></span> <span>public</span> <span>static</span> <span>void</span> Convert(<span>float</span>[][] from, <span>short</span>[][] to) { <span>for</span> (<span>int</span> j = 0; j < from.Length; j++) <span>for</span> (<span>int</span> i = 0; i < from[i].Length; i++) to[i][j] = (<span>short</span>) (from[i][j] * (32767.0f)); } <span>/// <summary></span> <span>/// Converts a array of signed 32-bit float samples</span> <span>/// into a array of signed 16-bit integer samples.</span> <span>/// </summary></span> <span>/// <param name="from">The original sample.</param></span> <span>/// <param name="to">The resulting sample.</param></span> <span>public</span> <span>static</span> <span>void</span> Convert(<span>float</span>[] from, <span>short</span>[] to) { <span>for</span> (<span>int</span> i = 0; i < from.Length; i++) to[i] = (<span>short</span>) (from[i] * (32767.0f)); } <span>/// <summary></span> <span>/// Converts a signed 32-bit float sample</span> <span>/// into a signed 16-bit integer sample.</span> <span>/// </summary></span> <span>/// <param name="from">The original sample.</param></span> <span>/// <param name="to">The resulting sample.</param></span> <span>public</span> <span>static</span> <span>void</span> Convert(<span>float</span> from, <span>out</span> <span>short</span> to) { to = (<span>short</span>) (from * (32767.0f)); } <span>#endregion</span> <span>#region</span> From Single (<span>float</span>) to Int32 (<span>int</span>) <span>/// <summary></span> <span>/// Converts a matrix of signed 32-bit float samples</span> <span>/// into a matrix of signed 32-bit integer samples.</span> <span>/// </summary></span> <span>/// <param name="from">The original sample.</param></span> <span>/// <param name="to">The resulting sample.</param></span> <span>public</span> <span>static</span> <span>void</span> Convert(<span>float</span>[][] from, Int32[][] to) { <span>for</span> (<span>int</span> j = 0; j < from.Length; j++) <span>for</span> (<span>int</span> i = 0; i < from[i].Length; i++) to[i][j] = (<span>int</span>)((<span>double</span>)from[i][j] * 0x7FFFFFFF); } <span>/// <summary></span> <span>/// Converts a array of signed 32-bit float samples</span> <span>/// into a array of signed 32-bit integer samples.</span> <span>/// </summary></span> <span>/// <param name="from">The original sample.</param></span> <span>/// <param name="to">The resulting sample.</param></span> <span>public</span> <span>static</span> <span>void</span> Convert(<span>float</span>[] from, Int32[] to) { <span>for</span> (<span>int</span> i = 0; i < from.Length; i++) to[i] = (<span>int</span>)((<span>double</span>)from[i] * 0x7FFFFFFF); } <span>/// <summary></span> <span>/// Converts a signed 32-bit floating-point sample</span> <span>/// into a signed 32-bit integer sample.</span> <span>/// </summary></span> <span>/// <param name="from">The original sample.</param></span> <span>/// <param name="to">The resulting sample.</param></span> <span>public</span> <span>static</span> <span>void</span> Convert(<span>float</span> from, <span>out</span> Int32 to) { to = (<span>int</span>)((<span>double</span>)from * 0x7FFFFFFF); } <span>#endregion</span> <span>#endregion</span> } } |
Considerações
Note, porém, que conversões raramente são perfeitas. Isto é verdade para quase tudo, especialmente para sinais digitais. Converter de uma codifiação para outra pode introduzir erros de conversão nos dados. Para ajudar nesta questão, foi inventada a técnica conhecida como dithering. Dithering é o mesmo que propositalmente adicionar ruído num sinal.
Ruído? Sim, ruído. Ruído não é sempre uma coisa ruim. Basta dar uma olhada nos exemplos de imagens na Wikipedia e você logo entenderá isto. Infelizmente, esta classe ainda não suporta dithering, poderá suportar no futuro caso surja necessidade.
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