channel_layout.c File Reference

audio channel layout utility functions More...

#include "avstring.h"
#include "avutil.h"
#include "channel_layout.h"
#include "bprint.h"
#include "common.h"

Go to the source code of this file.

Data Structures
struct	channel_name

Functions
static const char *	get_channel_name (int channel_id)
static uint64_t	get_channel_layout_single (const char *name, int name_len)
uint64_t	av_get_channel_layout (const char *name)
	Return a channel layout id that matches name, or 0 if no match is found.
void	av_bprint_channel_layout (struct AVBPrint *bp, int nb_channels, uint64_t channel_layout)
	Append a description of a channel layout to a bprint buffer.
void	av_get_channel_layout_string (char *buf, int buf_size, int nb_channels, uint64_t channel_layout)
	Return a description of a channel layout.
int	av_get_channel_layout_nb_channels (uint64_t channel_layout)
	Return the number of channels in the channel layout.
int64_t	av_get_default_channel_layout (int nb_channels)
	Return default channel layout for a given number of channels.
int	av_get_channel_layout_channel_index (uint64_t channel_layout, uint64_t channel)
	Get the index of a channel in channel_layout.
const char *	av_get_channel_name (uint64_t channel)
	Get the name of a given channel.
const char *	av_get_channel_description (uint64_t channel)
	Get the description of a given channel.
uint64_t	av_channel_layout_extract_channel (uint64_t channel_layout, int index)
	Get the channel with the given index in channel_layout.
int	av_get_standard_channel_layout (unsigned index, uint64_t *layout, const char **name)
	Get the value and name of a standard channel layout.

Variables
static struct channel_name	channel_names []
struct {
const char *   name
int   nb_channels
uint64_t   layout
}	channel_layout_map []

Detailed Description

audio channel layout utility functions

Definition in file channel_layout.c.

Function Documentation

static const char* get_channel_name ( int  channel_id )

static

Definition at line 65 of file channel_layout.c.

Referenced by av_bprint_channel_layout(), and av_get_channel_name().

static uint64_t get_channel_layout_single ( const char *  name, int  name_len  )

static

Definition at line 105 of file channel_layout.c.

Referenced by av_get_channel_layout().

Variable Documentation

struct channel_name channel_names[]

static

Initial value:

= {
     [0] = { "FL",        "front left"            },
     [1] = { "FR",        "front right"           },
     [2] = { "FC",        "front center"          },
     [3] = { "LFE",       "low frequency"         },
     [4] = { "BL",        "back left"             },
     [5] = { "BR",        "back right"            },
     [6] = { "FLC",       "front left-of-center"  },
     [7] = { "FRC",       "front right-of-center" },
     [8] = { "BC",        "back center"           },
     [9] = { "SL",        "side left"             },
    [10] = { "SR",        "side right"            },
    [11] = { "TC",        "top center"            },
    [12] = { "TFL",       "top front left"        },
    [13] = { "TFC",       "top front center"      },
    [14] = { "TFR",       "top front right"       },
    [15] = { "TBL",       "top back left"         },
    [16] = { "TBC",       "top back center"       },
    [17] = { "TBR",       "top back right"        },
    [29] = { "DL",        "downmix left"          },
    [30] = { "DR",        "downmix right"         },
    [31] = { "WL",        "wide left"             },
    [32] = { "WR",        "wide right"            },
    [33] = { "SDL",       "surround direct left"  },
    [34] = { "SDR",       "surround direct right" },
    [35] = { "LFE2",      "low frequency 2"       },
}

Definition at line 37 of file channel_layout.c.

const char* name

Definition at line 73 of file channel_layout.c.

int nb_channels

Examples:

doc/examples/decoding_encoding.c, doc/examples/muxing.c, and doc/examples/resampling_audio.c.

Definition at line 74 of file channel_layout.c.

Referenced by av_asrc_buffer_add_buffer(), av_buffersink_read_samples(), av_samples_copy(), av_samples_fill_arrays(), av_samples_set_silence(), avfilter_copy_buf_props(), avfilter_ref_buffer(), buffer_offset(), celt_header(), channelmap_config_input(), config_audio_output(), config_props_output(), ff_buffersink_read_samples_compat(), ff_default_get_audio_buffer(), ff_filter_frame_needs_framing(), ff_mpa_l2_select_table(), fill_coding_method_array(), fill_samples(), filter_frame(), get_audio_frame(), init(), main(), MPA_encode_frame(), plot_spectrum_column(), return_audio_frame(), select_channel_layout(), and send_silence().

uint64_t layout

Definition at line 75 of file channel_layout.c.

Referenced by av_bprint_channel_layout(), av_get_channel_layout(), avfilter_get_audio_buffer_ref_from_frame(), clean_layout(), count_channels(), encode_init(), ff_alsa_open(), ff_mov_get_channel_layout_tag(), ff_truehd_layout(), filter_frame(), get_channel_layout_single(), mxf_read_pixel_layout(), opt_channel_layout(), output_configure(), parse_channel_name(), print_link_prop(), query_formats(), show_layouts(), and sniff_channel_order().

struct { ... } channel_layout_map[]

Initial value:

= {
    { "mono",        1,  AV_CH_LAYOUT_MONO },
    { "stereo",      2,  AV_CH_LAYOUT_STEREO },
    { "2.1",         3,  AV_CH_LAYOUT_2POINT1 },
    { "3.0",         3,  AV_CH_LAYOUT_SURROUND },
    { "3.0(back)",   3,  AV_CH_LAYOUT_2_1 },
    { "4.0",         4,  AV_CH_LAYOUT_4POINT0 },
    { "quad",        4,  AV_CH_LAYOUT_QUAD },
    { "quad(side)",  4,  AV_CH_LAYOUT_2_2 },
    { "3.1",         4,  AV_CH_LAYOUT_3POINT1 },
    { "5.0",         5,  AV_CH_LAYOUT_5POINT0_BACK },
    { "5.0(side)",   5,  AV_CH_LAYOUT_5POINT0 },
    { "4.1",         5,  AV_CH_LAYOUT_4POINT1 },
    { "5.1",         6,  AV_CH_LAYOUT_5POINT1_BACK },
    { "5.1(side)",   6,  AV_CH_LAYOUT_5POINT1 },
    { "6.0",         6,  AV_CH_LAYOUT_6POINT0 },
    { "6.0(front)",  6,  AV_CH_LAYOUT_6POINT0_FRONT },
    { "hexagonal",   6,  AV_CH_LAYOUT_HEXAGONAL },
    { "6.1",         7,  AV_CH_LAYOUT_6POINT1 },
    { "6.1",         7,  AV_CH_LAYOUT_6POINT1_BACK },
    { "6.1(front)",  7,  AV_CH_LAYOUT_6POINT1_FRONT },
    { "7.0",         7,  AV_CH_LAYOUT_7POINT0 },
    { "7.0(front)",  7,  AV_CH_LAYOUT_7POINT0_FRONT },
    { "7.1",         8,  AV_CH_LAYOUT_7POINT1 },
    { "7.1(wide)",   8,  AV_CH_LAYOUT_7POINT1_WIDE },
    { "octagonal",   8,  AV_CH_LAYOUT_OCTAGONAL },
    { "downmix",     2,  AV_CH_LAYOUT_STEREO_DOWNMIX, },
}

Referenced by av_bprint_channel_layout(), av_get_default_channel_layout(), av_get_standard_channel_layout(), and get_channel_layout_single().