/// <summary>
/// </summary>
/// <param name="channelLayout">see <see cref="AVChannelLayout"/></param>
/// <param name="nbSamples">recommended use <see cref="AVCodecContext.frame_size"/></param>
/// <param name="format"><see cref="AVCodecContext.sample_fmt"/></param>
/// <param name="sampleRate"></param>
/// <param name="align">
/// Required buffer size alignment. If equal to 0, alignment will be chosen automatically for
/// the current CPU. It is highly recommended to pass 0 here unless you know what you are doing.
/// </param>
public AudioFrame(AVChannelLayout channelLayout, int nbSamples, AVSampleFormat format, int sampleRate = 0, int align = 0)
: this(ffmpeg.av_get_channel_layout_nb_channels((ulong)channelLayout), nbSamples, format, sampleRate, align)
{
unsafe
{
pFrame->channel_layout = (ulong)channelLayout;
}
}
public AudioFormat(int sampleRate, AVChannelLayout channelLayout, AVSampleFormat sampleFormat)
{
SampleRate = sampleRate;
ChannelLayout = channelLayout;
SampleFormat = sampleFormat;
BitsPerSample = GetBytePerSample(sampleFormat) * 8;
ValidBitsPerSample = SampleFormat.EqualsType(AVSampleFormat.Int32) ? 24 : BitsPerSample;
}
public void Init(AVChannelLayout channelLayout, int nbSamples, AVSampleFormat format, int sampleRate = 0, int align = 0)
{
Clear();
AllocBuffer(ffmpeg.av_get_channel_layout_nb_channels((ulong)channelLayout), nbSamples, format, sampleRate, align);
unsafe
{
pFrame->channel_layout = (ulong)channelLayout;
}
}
public AudioFormat(int sampleRate, AVChannelLayout channelLayout, AVSampleFormat sampleFormat)
{
SampleRate = sampleRate;
ChannelLayout = channelLayout;
SampleFormat = sampleFormat;
Channels = GetChannels(channelLayout);
BitsPerSample = GetBytePerSample(sampleFormat) * 8;
SampleType = GetSampleType(sampleFormat);
IsPlanarFormat = sampleFormat.IsPlanar();
LineCount = IsPlanarFormat ? Channels : 1;
LineBlock = IsPlanarFormat ? (BitsPerSample >> 3) : (BitsPerSample >> 3) * Channels;
ValidBitsPerSample = SampleFormat.EqualsType(AVSampleFormat.Int32) ? 24 : BitsPerSample;
}
public AudioFormat Match(IEnumerable <int> sampleRates, IEnumerable <AVSampleFormat> sampleFormats, IEnumerable <AVChannelLayout> channelLayouts)
{
int sampleRate = SampleRate;
if (sampleRates != null)
{
foreach (var sr in sampleRates.OrderBy(sr => sr))
{
sampleRate = sr;
if (sr >= SampleRate)
{
break;
}
}
}
AVSampleFormat sampleFormat = SampleFormat;
if (sampleFormats != null)
{
foreach (var sf in sampleFormats.OrderBy(sf => GetBytePerSample(sf)))
{
sampleFormat = sf;
if (GetBytePerSample(sf) >= BitsPerSample >> 3)
{
break;
}
}
}
AVChannelLayout channelLayout = ChannelLayout;
if (channelLayouts != null)
{
foreach (var cl in channelLayouts.OrderBy(cl => GetChannels(cl)))
{
channelLayout = cl;
if (GetChannels(cl) >= Channels)
{
break;
}
}
}
return(new AudioFormat(sampleRate, channelLayout, sampleFormat));
}
/// <summary>
/// Return the number of channels in the channel layout use <see cref="ffmpeg.av_get_channel_layout_nb_channels(ulong)"/>
/// </summary>
/// <param name="channelLayout"></param>
/// <returns></returns>
public static int ToChannels(this AVChannelLayout channelLayout)
{
return(ffmpeg.av_get_channel_layout_nb_channels((ulong)channelLayout));
}
public static extern SwrContext *swr_alloc_set_opts(SwrContext *s, AVChannelLayout out_ch_layout, AVSampleFormat out_sample_fmt, int out_sample_rate, AVChannelLayout in_ch_layout, AVSampleFormat in_sample_fmt, int in_sample_rate, int log_offset, void *log_ctx);
public static extern byte *av_get_channel_description(AVChannelLayout channel);
public static extern byte *av_get_channel_name(AVChannelLayout channel);
public static extern AVChannelLayout av_channel_layout_extract_channel(AVChannelLayout channel_layout, int index);
public static extern int av_get_channel_layout_channel_index(AVChannelLayout channel_layout, AVChannelLayout channel);
public static extern int av_get_channel_layout_nb_channels(AVChannelLayout channel_layout);
public static extern void av_get_channel_layout_string(byte *buf, int buf_size, int nb_channels, AVChannelLayout channel_layout);
public static int GetChannels(AVChannelLayout channelLayout)
{
return(Internal.FFmpeg.av_get_channel_layout_nb_channels(channelLayout));
}
public extern static int swr_build_matrix(AVChannelLayout in_layout, AVChannelLayout out_layout, double center_mix_level, double surround_mix_level, double lfe_mix_level, double rematrix_maxval, double rematrix_volume, double *matrix, int stride, AVMatrixEncoding matrix_encoding, void *log_ctx);
