gst_buffer_add_audio_downmix_meta ()

GstAudioDownmixMeta *
gst_buffer_add_audio_downmix_meta (GstBuffer *buffer,
                                   const GstAudioChannelPosition *from_position,
                                   gint from_channels,
                                   const GstAudioChannelPosition *to_position,
                                   gint to_channels,
                                   const gfloat **matrix);

Attaches GstAudioDownmixMeta metadata to buffer with the given parameters.

matrix is an two-dimensional array of to_channels times from_channels coefficients, i.e. the i-th output channels is constructed by multiplicating the input channels with the coefficients in matrix [i] and taking the sum of the results.

gst_buffer_get_audio_downmix_meta()

#define gst_buffer_get_audio_downmix_meta(b) ((GstAudioDownmixMeta*)gst_buffer_get_meta((b), GST_AUDIO_DOWNMIX_META_API_TYPE))

gst_buffer_get_audio_downmix_meta_for_channels ()

GstAudioDownmixMeta *
gst_buffer_get_audio_downmix_meta_for_channels
                               (GstBuffer *buffer,
                                const GstAudioChannelPosition *to_position,
                                gint to_channels);

Find the GstAudioDownmixMeta on buffer for the given destination channel positions.

gst_buffer_add_audio_clipping_meta ()

GstAudioClippingMeta *
gst_buffer_add_audio_clipping_meta (GstBuffer *buffer,
                                    GstFormat format,
                                    guint64 start,
                                    guint64 end);

Attaches GstAudioClippingMeta metadata to buffer with the given parameters.

Since: 1.8

gst_buffer_get_audio_clipping_meta()

#define gst_buffer_get_audio_clipping_meta(b) ((GstAudioClippingMeta*)gst_buffer_get_meta((b), GST_AUDIO_CLIPPING_META_API_TYPE))

struct GstAudioDownmixMeta

struct GstAudioDownmixMeta {
  GstMeta      meta;

  GstAudioChannelPosition *from_position;
  GstAudioChannelPosition *to_position;
  gint        from_channels, to_channels;
  gfloat       **matrix;
};

Extra buffer metadata describing audio downmixing matrix. This metadata is attached to audio buffers and contains a matrix to downmix the buffer number of channels to channels .

matrix is an two-dimensional array of to_channels times from_channels coefficients, i.e. the i-th output channels is constructed by multiplicating the input channels with the coefficients in matrix [i] and taking the sum of the results.

struct GstAudioClippingMeta

struct GstAudioClippingMeta {
  GstMeta   meta;

  GstFormat format;
  guint64   start;
  guint64   end;
};

Extra buffer metadata describing how much audio has to be clipped from the start or end of a buffer. This is used for compressed formats, where the first frame usually has some additional samples due to encoder and decoder delays, and the last frame usually has some additional samples to be able to fill the complete last frame.

This is used to ensure that decoded data in the end has the same amount of samples, and multiply decoded streams can be gaplessly concatenated.

Note: If clipping of the start is done by adjusting the segment, this meta has to be dropped from buffers as otherwise clipping could happen twice.

Since: 1.8