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avutil/channel_layout: Add a new channel layout API

Browse Source 
The new API is more extensible and allows for custom layouts.
More accurate information is exported, eg for decoders that do not
set a channel layout, lavc will not make one up for them.

Deprecate the old API working with just uint64_t bitmasks.

Expanded and completed by Vittorio Giovara <vittorio.giovara@gmail.com>
and James Almer <jamrial@gmail.com>.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
Signed-off-by: James Almer <jamrial@gmail.com>
release/5.1
Anton Khirnov 12 years ago committed by James Almer
parent dcc3f62270
commit 086a804806
3 changed files with 1086 additions and 103 deletions
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  1. 663
      libavutil/channel_layout.c
  2. 525
      libavutil/channel_layout.h
  3. 1
      libavutil/version.h

663
libavutil/channel_layout.c
Unescape View File

@ -32,6 +32,7 @@
#include "common.h"
#include "error.h"
#include "macros.h"
#include "opt.h"
struct channel_name {
const char *name;
@ -39,81 +40,149 @@ struct channel_name {
};
static const struct channel_name channel_names[] = {
[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" },
[36] = { "TSL", "top side left" },
[37] = { "TSR", "top side right" },
[38] = { "BFC", "bottom front center" },
[39] = { "BFL", "bottom front left" },
[40] = { "BFR", "bottom front right" },
[AV_CHAN_FRONT_LEFT ] = { "FL", "front left" },
[AV_CHAN_FRONT_RIGHT ] = { "FR", "front right" },
[AV_CHAN_FRONT_CENTER ] = { "FC", "front center" },
[AV_CHAN_LOW_FREQUENCY ] = { "LFE", "low frequency" },
[AV_CHAN_BACK_LEFT ] = { "BL", "back left" },
[AV_CHAN_BACK_RIGHT ] = { "BR", "back right" },
[AV_CHAN_FRONT_LEFT_OF_CENTER ] = { "FLC", "front left-of-center" },
[AV_CHAN_FRONT_RIGHT_OF_CENTER] = { "FRC", "front right-of-center" },
[AV_CHAN_BACK_CENTER ] = { "BC", "back center" },
[AV_CHAN_SIDE_LEFT ] = { "SL", "side left" },
[AV_CHAN_SIDE_RIGHT ] = { "SR", "side right" },
[AV_CHAN_TOP_CENTER ] = { "TC", "top center" },
[AV_CHAN_TOP_FRONT_LEFT ] = { "TFL", "top front left" },
[AV_CHAN_TOP_FRONT_CENTER ] = { "TFC", "top front center" },
[AV_CHAN_TOP_FRONT_RIGHT ] = { "TFR", "top front right" },
[AV_CHAN_TOP_BACK_LEFT ] = { "TBL", "top back left" },
[AV_CHAN_TOP_BACK_CENTER ] = { "TBC", "top back center" },
[AV_CHAN_TOP_BACK_RIGHT ] = { "TBR", "top back right" },
[AV_CHAN_STEREO_LEFT ] = { "DL", "downmix left" },
[AV_CHAN_STEREO_RIGHT ] = { "DR", "downmix right" },
[AV_CHAN_WIDE_LEFT ] = { "WL", "wide left" },
[AV_CHAN_WIDE_RIGHT ] = { "WR", "wide right" },
[AV_CHAN_SURROUND_DIRECT_LEFT ] = { "SDL", "surround direct left" },
[AV_CHAN_SURROUND_DIRECT_RIGHT] = { "SDR", "surround direct right" },
[AV_CHAN_LOW_FREQUENCY_2 ] = { "LFE2", "low frequency 2" },
[AV_CHAN_TOP_SIDE_LEFT ] = { "TSL", "top side left" },
[AV_CHAN_TOP_SIDE_RIGHT ] = { "TSR", "top side right" },
[AV_CHAN_BOTTOM_FRONT_CENTER ] = { "BFC", "bottom front center" },
[AV_CHAN_BOTTOM_FRONT_LEFT ] = { "BFL", "bottom front left" },
[AV_CHAN_BOTTOM_FRONT_RIGHT ] = { "BFR", "bottom front right" },
};
static const char *get_channel_name(int channel_id)
static const char *get_channel_name(enum AVChannel channel_id)
{
if (channel_id < 0 || channel_id >= FF_ARRAY_ELEMS(channel_names))
if ((unsigned) channel_id >= FF_ARRAY_ELEMS(channel_names) ||
!channel_names[channel_id].name)
return NULL;
return channel_names[channel_id].name;
}
static const struct {
void av_channel_name_bprint(AVBPrint *bp, enum AVChannel channel_id)
{
if ((unsigned)channel_id < FF_ARRAY_ELEMS(channel_names))
av_bprintf(bp, "%s", channel_names[channel_id].name);
else if (channel_id == AV_CHAN_NONE)
av_bprintf(bp, "NONE");
else
av_bprintf(bp, "USR%d", channel_id);
}
int av_channel_name(char *buf, size_t buf_size, enum AVChannel channel_id)
{
AVBPrint bp;
if (!buf && buf_size)
return AVERROR(EINVAL);
av_bprint_init_for_buffer(&bp, buf, buf_size);
av_channel_name_bprint(&bp, channel_id);
return bp.len;
}
void av_channel_description_bprint(AVBPrint *bp, enum AVChannel channel_id)
{
if ((unsigned)channel_id < FF_ARRAY_ELEMS(channel_names))
av_bprintf(bp, "%s", channel_names[channel_id].description);
else
av_bprintf(bp, "user %d", channel_id);
}
int av_channel_description(char *buf, size_t buf_size, enum AVChannel channel_id)
{
AVBPrint bp;
if (!buf && buf_size)
return AVERROR(EINVAL);
av_bprint_init_for_buffer(&bp, buf, buf_size);
av_channel_description_bprint(&bp, channel_id);
return bp.len;
}
enum AVChannel av_channel_from_string(const char *str)
{
int i;
char *endptr = (char *)str;
enum AVChannel id = AV_CHAN_NONE;
for (i = 0; i < FF_ARRAY_ELEMS(channel_names); i++) {
if (channel_names[i].name && !strcmp(str, channel_names[i].name))
return i;
}
if (!strncmp(str, "USR", 3)) {
const char *p = str + 3;
id = strtol(p, &endptr, 0);
}
if (id >= 0 && !*endptr)
return id;
return AV_CHAN_NONE;
}
struct channel_layout_name {
const char *name;
int nb_channels;
uint64_t layout;
} channel_layout_map[] = {
{ "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(back)", 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_BACK },
{ "7.1(wide-side)", 8, AV_CH_LAYOUT_7POINT1_WIDE },
{ "octagonal", 8, AV_CH_LAYOUT_OCTAGONAL },
{ "hexadecagonal", 16, AV_CH_LAYOUT_HEXADECAGONAL },
{ "downmix", 2, AV_CH_LAYOUT_STEREO_DOWNMIX, },
{ "22.2", 24, AV_CH_LAYOUT_22POINT2, },
AVChannelLayout layout;
};
static const struct channel_layout_name channel_layout_map[] = {
{ "mono", AV_CHANNEL_LAYOUT_MONO },
{ "stereo", AV_CHANNEL_LAYOUT_STEREO },
{ "stereo", AV_CHANNEL_LAYOUT_STEREO_DOWNMIX },
{ "2.1", AV_CHANNEL_LAYOUT_2POINT1 },
{ "3.0", AV_CHANNEL_LAYOUT_SURROUND },
{ "3.0(back)", AV_CHANNEL_LAYOUT_2_1 },
{ "4.0", AV_CHANNEL_LAYOUT_4POINT0 },
{ "quad", AV_CHANNEL_LAYOUT_QUAD },
{ "quad(side)", AV_CHANNEL_LAYOUT_2_2 },
{ "3.1", AV_CHANNEL_LAYOUT_3POINT1 },
{ "5.0", AV_CHANNEL_LAYOUT_5POINT0_BACK },
{ "5.0(side)", AV_CHANNEL_LAYOUT_5POINT0 },
{ "4.1", AV_CHANNEL_LAYOUT_4POINT1 },
{ "5.1", AV_CHANNEL_LAYOUT_5POINT1_BACK },
{ "5.1(side)", AV_CHANNEL_LAYOUT_5POINT1 },
{ "6.0", AV_CHANNEL_LAYOUT_6POINT0 },
{ "6.0(front)", AV_CHANNEL_LAYOUT_6POINT0_FRONT },
{ "hexagonal", AV_CHANNEL_LAYOUT_HEXAGONAL },
{ "6.1", AV_CHANNEL_LAYOUT_6POINT1 },
{ "6.1(back)", AV_CHANNEL_LAYOUT_6POINT1_BACK },
{ "6.1(front)", AV_CHANNEL_LAYOUT_6POINT1_FRONT },
{ "7.0", AV_CHANNEL_LAYOUT_7POINT0 },
{ "7.0(front)", AV_CHANNEL_LAYOUT_7POINT0_FRONT },
{ "7.1", AV_CHANNEL_LAYOUT_7POINT1 },
{ "7.1(wide)", AV_CHANNEL_LAYOUT_7POINT1_WIDE_BACK },
{ "7.1(wide-side)", AV_CHANNEL_LAYOUT_7POINT1_WIDE },
{ "octagonal", AV_CHANNEL_LAYOUT_OCTAGONAL },
{ "hexadecagonal", AV_CHANNEL_LAYOUT_HEXADECAGONAL },
{ "downmix", AV_CHANNEL_LAYOUT_STEREO_DOWNMIX, },
{ "22.2", AV_CHANNEL_LAYOUT_22POINT2, },
};
#if FF_API_OLD_CHANNEL_LAYOUT
FF_DISABLE_DEPRECATION_WARNINGS
static uint64_t get_channel_layout_single(const char *name, int name_len)
{
int i;
@ -123,7 +192,7 @@ static uint64_t get_channel_layout_single(const char *name, int name_len)
for (i = 0; i < FF_ARRAY_ELEMS(channel_layout_map); i++) {
if (strlen(channel_layout_map[i].name) == name_len &&
!memcmp(channel_layout_map[i].name, name, name_len))
return channel_layout_map[i].layout;
return channel_layout_map[i].layout.u.mask;
}
for (i = 0; i < FF_ARRAY_ELEMS(channel_names); i++)
if (channel_names[i].name &&
@ -191,8 +260,8 @@ void av_bprint_channel_layout(struct AVBPrint *bp,
nb_channels = av_get_channel_layout_nb_channels(channel_layout);
for (i = 0; i < FF_ARRAY_ELEMS(channel_layout_map); i++)
if (nb_channels == channel_layout_map[i].nb_channels &&
channel_layout == channel_layout_map[i].layout) {
if (nb_channels == channel_layout_map[i].layout.nb_channels &&
channel_layout == channel_layout_map[i].layout.u.mask) {
av_bprintf(bp, "%s", channel_layout_map[i].name);
return;
}
@ -233,8 +302,8 @@ int av_get_channel_layout_nb_channels(uint64_t channel_layout)
int64_t av_get_default_channel_layout(int nb_channels) {
int i;
for (i = 0; i < FF_ARRAY_ELEMS(channel_layout_map); i++)
if (nb_channels == channel_layout_map[i].nb_channels)
return channel_layout_map[i].layout;
if (nb_channels == channel_layout_map[i].layout.nb_channels)
return channel_layout_map[i].layout.u.mask;
return 0;
}
@ -289,7 +358,459 @@ int av_get_standard_channel_layout(unsigned index, uint64_t *layout,
{
if (index >= FF_ARRAY_ELEMS(channel_layout_map))
return AVERROR_EOF;
if (layout) *layout = channel_layout_map[index].layout;
if (layout) *layout = channel_layout_map[index].layout.u.mask;
if (name) *name = channel_layout_map[index].name;
return 0;
}
FF_ENABLE_DEPRECATION_WARNINGS
#endif
int av_channel_layout_from_mask(AVChannelLayout *channel_layout,
uint64_t mask)
{
if (!mask)
return AVERROR(EINVAL);
channel_layout->order = AV_CHANNEL_ORDER_NATIVE;
channel_layout->nb_channels = av_popcount64(mask);
channel_layout->u.mask = mask;
return 0;
}
int av_channel_layout_from_string(AVChannelLayout *channel_layout,
const char *str)
{
int i;
int channels = 0, nb_channels = 0, native = 1;
enum AVChannel highest_channel = AV_CHAN_NONE;
const char *dup;
char *chlist, *end;
uint64_t mask = 0;
/* channel layout names */
for (i = 0; i < FF_ARRAY_ELEMS(channel_layout_map); i++) {
if (channel_layout_map[i].name && !strcmp(str, channel_layout_map[i].name)) {
*channel_layout = channel_layout_map[i].layout;
return 0;
}
}
chlist = av_strdup(str);
if (!chlist)
return AVERROR(ENOMEM);
/* channel names */
av_sscanf(str, "%d channels (%[^)]", &nb_channels, chlist);
end = strchr(str, ')');
dup = chlist;
while (*dup) {
char *channel, *chname;
int ret = av_opt_get_key_value(&dup, "@", "+", AV_OPT_FLAG_IMPLICIT_KEY, &channel, &chname);
if (ret < 0) {
av_free(chlist);
return ret;
}
if (*dup)
dup++; // skip separator
if (channel && !*channel)
av_freep(&channel);
for (i = 0; i < FF_ARRAY_ELEMS(channel_names); i++) {
if (channel_names[i].name && !strcmp(channel ? channel : chname, channel_names[i].name)) {
if (channel || i < highest_channel || mask & (1ULL << i))
native = 0; // Not a native layout, use a custom one
highest_channel = i;
mask |= 1ULL << i;
break;
}
}
if (!channel && i >= FF_ARRAY_ELEMS(channel_names)) {
char *endptr = chname;
enum AVChannel id = AV_CHAN_NONE;
if (!strncmp(chname, "USR", 3)) {
const char *p = chname + 3;
id = strtol(p, &endptr, 0);
}
if (id < 0 || *endptr) {
native = 0; // Unknown channel name
channels = 0;
mask = 0;
av_free(chname);
break;
}
if (id > 63)
native = 0; // Not a native layout, use a custom one
else {
if (id < highest_channel || mask & (1ULL << id))
native = 0; // Not a native layout, use a custom one
highest_channel = id;
mask |= 1ULL << id;
}
}
channels++;
av_free(channel);
av_free(chname);
}
if (mask && native) {
av_free(chlist);
if (nb_channels && ((nb_channels != channels) || (!end || *++end)))
return AVERROR(EINVAL);
av_channel_layout_from_mask(channel_layout, mask);
return 0;
}
/* custom layout of channel names */
if (channels && !native) {
int idx = 0;
if (nb_channels && ((nb_channels != channels) || (!end || *++end))) {
av_free(chlist);
return AVERROR(EINVAL);
}
channel_layout->u.map = av_calloc(channels, sizeof(*channel_layout->u.map));
if (!channel_layout->u.map) {
av_free(chlist);
return AVERROR(ENOMEM);
}
channel_layout->order = AV_CHANNEL_ORDER_CUSTOM;
channel_layout->nb_channels = channels;
dup = chlist;
while (*dup) {
char *channel, *chname;
int ret = av_opt_get_key_value(&dup, "@", "+", AV_OPT_FLAG_IMPLICIT_KEY, &channel, &chname);
if (ret < 0) {
av_freep(&channel_layout->u.map);
av_free(chlist);
return ret;
}
if (*dup)
dup++; // skip separator
for (i = 0; i < FF_ARRAY_ELEMS(channel_names); i++) {
if (channel_names[i].name && !strcmp(channel ? channel : chname, channel_names[i].name)) {
channel_layout->u.map[idx].id = i;
if (channel)
av_strlcpy(channel_layout->u.map[idx].name, chname, sizeof(channel_layout->u.map[idx].name));
idx++;
break;
}
}
if (i >= FF_ARRAY_ELEMS(channel_names)) {
const char *p = (channel ? channel : chname) + 3;
channel_layout->u.map[idx].id = strtol(p, NULL, 0);
if (channel)
av_strlcpy(channel_layout->u.map[idx].name, chname, sizeof(channel_layout->u.map[idx].name));
idx++;
}
av_free(channel);
av_free(chname);
}
return 0;
}
av_freep(&chlist);
errno = 0;
mask = strtoull(str, &end, 0);
/* channel layout mask */
if (!errno && !*end && !strchr(str, '-') && mask) {
av_channel_layout_from_mask(channel_layout, mask);
return 0;
}
errno = 0;
channels = strtol(str, &end, 10);
/* number of channels */
if (!errno && !strcmp(end, "c") && channels > 0) {
av_channel_layout_default(channel_layout, channels);
if (channel_layout->order == AV_CHANNEL_ORDER_NATIVE)
return 0;
}
/* number of unordered channels */
if (!errno && (!strcmp(end, "C") || !strcmp(end, " channels"))
&& channels > 0) {
channel_layout->order = AV_CHANNEL_ORDER_UNSPEC;
channel_layout->nb_channels = channels;
return 0;
}
return AVERROR(EINVAL);
}
void av_channel_layout_uninit(AVChannelLayout *channel_layout)
{
if (channel_layout->order == AV_CHANNEL_ORDER_CUSTOM)
av_freep(&channel_layout->u.map);
memset(channel_layout, 0, sizeof(*channel_layout));
}
int av_channel_layout_copy(AVChannelLayout *dst, const AVChannelLayout *src)
{
av_channel_layout_uninit(dst);
*dst = *src;
if (src->order == AV_CHANNEL_ORDER_CUSTOM) {
dst->u.map = av_malloc_array(src->nb_channels, sizeof(*dst->u.map));
if (!dst->u.map)
return AVERROR(ENOMEM);
memcpy(dst->u.map, src->u.map, src->nb_channels * sizeof(*src->u.map));
}
return 0;
}
int av_channel_layout_describe_bprint(const AVChannelLayout *channel_layout,
AVBPrint *bp)
{
int i;
switch (channel_layout->order) {
case AV_CHANNEL_ORDER_NATIVE:
for (i = 0; i < FF_ARRAY_ELEMS(channel_layout_map); i++)
if (channel_layout->u.mask == channel_layout_map[i].layout.u.mask) {
av_bprintf(bp, "%s", channel_layout_map[i].name);
return 0;
}
// fall-through
case AV_CHANNEL_ORDER_CUSTOM:
if (channel_layout->nb_channels)
av_bprintf(bp, "%d channels (", channel_layout->nb_channels);
for (i = 0; i < channel_layout->nb_channels; i++) {
enum AVChannel ch = av_channel_layout_channel_from_index(channel_layout, i);
const char *channel = get_channel_name(ch);
if (i)
av_bprintf(bp, "+");
if (channel)
av_bprintf(bp, "%s", channel);
else
av_bprintf(bp, "USR%d", ch);
if (channel_layout->order == AV_CHANNEL_ORDER_CUSTOM &&
channel_layout->u.map[i].name[0])
av_bprintf(bp, "@%s", channel_layout->u.map[i].name);
}
if (channel_layout->nb_channels) {
av_bprintf(bp, ")");
return 0;
}
// fall-through
case AV_CHANNEL_ORDER_UNSPEC:
av_bprintf(bp, "%d channels", channel_layout->nb_channels);
return 0;
default:
return AVERROR(EINVAL);
}
}
int av_channel_layout_describe(const AVChannelLayout *channel_layout,
char *buf, size_t buf_size)
{
AVBPrint bp;
int ret;
if (!buf && buf_size)
return AVERROR(EINVAL);
av_bprint_init_for_buffer(&bp, buf, buf_size);
ret = av_channel_layout_describe_bprint(channel_layout, &bp);
if (ret < 0)
return ret;
return bp.len;
}
enum AVChannel
av_channel_layout_channel_from_index(const AVChannelLayout *channel_layout,
unsigned int idx)
{
int i;
if (idx >= channel_layout->nb_channels)
return AV_CHAN_NONE;
switch (channel_layout->order) {
case AV_CHANNEL_ORDER_CUSTOM:
return channel_layout->u.map[idx].id;
case AV_CHANNEL_ORDER_NATIVE:
for (i = 0; i < 64; i++) {
if ((1ULL << i) & channel_layout->u.mask && !idx--)
return i;
}
default:
return AV_CHAN_NONE;
}
}
enum AVChannel
av_channel_layout_channel_from_string(const AVChannelLayout *channel_layout,
const char *str)
{
int index = av_channel_layout_index_from_string(channel_layout, str);
if (index < 0)
return AV_CHAN_NONE;
return av_channel_layout_channel_from_index(channel_layout, index);
}
int av_channel_layout_index_from_channel(const AVChannelLayout *channel_layout,
enum AVChannel channel)
{
int i;
if (channel == AV_CHAN_NONE)
return AVERROR(EINVAL);
switch (channel_layout->order) {
case AV_CHANNEL_ORDER_CUSTOM:
for (i = 0; i < channel_layout->nb_channels; i++)
if (channel_layout->u.map[i].id == channel)
return i;
return AVERROR(EINVAL);
case AV_CHANNEL_ORDER_NATIVE: {
uint64_t mask = channel_layout->u.mask;
if ((unsigned)channel > 63 || !(mask & (1ULL << channel)))
return AVERROR(EINVAL);
mask &= (1ULL << channel) - 1;
return av_popcount64(mask);
}
default:
return AVERROR(EINVAL);
}
}
int av_channel_layout_index_from_string(const AVChannelLayout *channel_layout,
const char *str)
{
char *chname;
enum AVChannel ch = AV_CHAN_NONE;
switch (channel_layout->order) {
case AV_CHANNEL_ORDER_CUSTOM:
chname = strstr(str, "@");
if (chname) {
char buf[16];
chname++;
av_strlcpy(buf, str, FFMIN(sizeof(buf), chname - str));
if (!*chname)
chname = NULL;
ch = av_channel_from_string(buf);
if (ch == AV_CHAN_NONE && *buf)
return AVERROR(EINVAL);
}
for (int i = 0; chname && i < channel_layout->nb_channels; i++) {
if (!strcmp(chname, channel_layout->u.map[i].name) &&
(ch == AV_CHAN_NONE || ch == channel_layout->u.map[i].id))
return i;
}
// fall-through
case AV_CHANNEL_ORDER_NATIVE:
ch = av_channel_from_string(str);
if (ch == AV_CHAN_NONE)
return AVERROR(EINVAL);
return av_channel_layout_index_from_channel(channel_layout, ch);
}
return AVERROR(EINVAL);
}
int av_channel_layout_check(const AVChannelLayout *channel_layout)
{
if (channel_layout->nb_channels <= 0)
return 0;
switch (channel_layout->order) {
case AV_CHANNEL_ORDER_NATIVE:
return av_popcount64(channel_layout->u.mask) == channel_layout->nb_channels;
case AV_CHANNEL_ORDER_CUSTOM:
if (!channel_layout->u.map)
return 0;
for (int i = 0; i < channel_layout->nb_channels; i++) {
if (channel_layout->u.map[i].id == AV_CHAN_NONE)
return 0;
}
return 1;
case AV_CHANNEL_ORDER_UNSPEC:
return 1;
default:
return 0;
}
}
int av_channel_layout_compare(const AVChannelLayout *chl, const AVChannelLayout *chl1)
{
int i;
/* different channel counts -> not equal */
if (chl->nb_channels != chl1->nb_channels)
return 1;
/* if only one is unspecified -> not equal */
if ((chl->order == AV_CHANNEL_ORDER_UNSPEC) !=
(chl1->order == AV_CHANNEL_ORDER_UNSPEC))
return 1;
/* both are unspecified -> equal */
else if (chl->order == AV_CHANNEL_ORDER_UNSPEC)
return 0;
/* can compare masks directly */
if (chl->order != AV_CHANNEL_ORDER_CUSTOM &&
chl->order == chl1->order)
return chl->u.mask != chl1->u.mask;
/* compare channel by channel */
for (i = 0; i < chl->nb_channels; i++)
if (av_channel_layout_channel_from_index(chl, i) !=
av_channel_layout_channel_from_index(chl1, i))
return 1;
return 0;
}
void av_channel_layout_default(AVChannelLayout *ch_layout, int nb_channels)
{
int i;
for (i = 0; i < FF_ARRAY_ELEMS(channel_layout_map); i++)
if (nb_channels == channel_layout_map[i].layout.nb_channels) {
*ch_layout = channel_layout_map[i].layout;
return;
}
ch_layout->order = AV_CHANNEL_ORDER_UNSPEC;
ch_layout->nb_channels = nb_channels;
}
const AVChannelLayout *av_channel_layout_standard(void **opaque)
{
uintptr_t i = (uintptr_t)*opaque;
const AVChannelLayout *ch_layout = NULL;
if (i < FF_ARRAY_ELEMS(channel_layout_map)) {
ch_layout = &channel_layout_map[i].layout;
*opaque = (void*)(i + 1);
}
return ch_layout;
}
uint64_t av_channel_layout_subset(const AVChannelLayout *channel_layout,
uint64_t mask)
{
uint64_t ret = 0;
int i;
if (channel_layout->order == AV_CHANNEL_ORDER_NATIVE)
return channel_layout->u.mask & mask;
for (i = 0; i < 64; i++)
if (mask & (1ULL << i) && av_channel_layout_index_from_channel(channel_layout, i) >= 0)
ret |= (1ULL << i);
return ret;
}

525
libavutil/channel_layout.h
Unescape View File

@ -23,6 +23,10 @@
#define AVUTIL_CHANNEL_LAYOUT_H
#include <stdint.h>
#include <stdlib.h>
#include "version.h"
#include "attributes.h"
/**
* @file
@ -34,6 +38,71 @@
* @{
*/
enum AVChannel {
///< Invalid channel index
AV_CHAN_NONE = -1,
AV_CHAN_FRONT_LEFT,
AV_CHAN_FRONT_RIGHT,
AV_CHAN_FRONT_CENTER,
AV_CHAN_LOW_FREQUENCY,
AV_CHAN_BACK_LEFT,
AV_CHAN_BACK_RIGHT,
AV_CHAN_FRONT_LEFT_OF_CENTER,
AV_CHAN_FRONT_RIGHT_OF_CENTER,
AV_CHAN_BACK_CENTER,
AV_CHAN_SIDE_LEFT,
AV_CHAN_SIDE_RIGHT,
AV_CHAN_TOP_CENTER,
AV_CHAN_TOP_FRONT_LEFT,
AV_CHAN_TOP_FRONT_CENTER,
AV_CHAN_TOP_FRONT_RIGHT,
AV_CHAN_TOP_BACK_LEFT,
AV_CHAN_TOP_BACK_CENTER,
AV_CHAN_TOP_BACK_RIGHT,
/** Stereo downmix. */
AV_CHAN_STEREO_LEFT = 29,
/** See above. */
AV_CHAN_STEREO_RIGHT,
AV_CHAN_WIDE_LEFT,
AV_CHAN_WIDE_RIGHT,
AV_CHAN_SURROUND_DIRECT_LEFT,
AV_CHAN_SURROUND_DIRECT_RIGHT,
AV_CHAN_LOW_FREQUENCY_2,
AV_CHAN_TOP_SIDE_LEFT,
AV_CHAN_TOP_SIDE_RIGHT,
AV_CHAN_BOTTOM_FRONT_CENTER,
AV_CHAN_BOTTOM_FRONT_LEFT,
AV_CHAN_BOTTOM_FRONT_RIGHT,
/** Channel is empty can be safely skipped. */
AV_CHAN_UNUSED = 0x200,
/** Channel contains data, but its position is unknown. */
AV_CHAN_UNKNOWN = 0x300,
};
enum AVChannelOrder {
/**
* Only the channel count is specified, without any further information
* about the channel order.
*/
AV_CHANNEL_ORDER_UNSPEC,
/**
* The native channel order, i.e. the channels are in the same order in
* which they are defined in the AVChannel enum. This supports up to 63
* different channels.
*/
AV_CHANNEL_ORDER_NATIVE,
/**
* The channel order does not correspond to any other predefined order and
* is stored as an explicit map. For example, this could be used to support
* layouts with 64 or more channels, or with empty/skipped (AV_CHAN_SILENCE)
* channels at arbitrary positions.
*/
AV_CHANNEL_ORDER_CUSTOM,
};
/**
* @defgroup channel_masks Audio channel masks
*
@ -46,41 +115,46 @@
*
* @{
*/
#define AV_CH_FRONT_LEFT 0x00000001
#define AV_CH_FRONT_RIGHT 0x00000002
#define AV_CH_FRONT_CENTER 0x00000004
#define AV_CH_LOW_FREQUENCY 0x00000008
#define AV_CH_BACK_LEFT 0x00000010
#define AV_CH_BACK_RIGHT 0x00000020
#define AV_CH_FRONT_LEFT_OF_CENTER 0x00000040
#define AV_CH_FRONT_RIGHT_OF_CENTER 0x00000080
#define AV_CH_BACK_CENTER 0x00000100
#define AV_CH_SIDE_LEFT 0x00000200
#define AV_CH_SIDE_RIGHT 0x00000400
#define AV_CH_TOP_CENTER 0x00000800
#define AV_CH_TOP_FRONT_LEFT 0x00001000
#define AV_CH_TOP_FRONT_CENTER 0x00002000
#define AV_CH_TOP_FRONT_RIGHT 0x00004000
#define AV_CH_TOP_BACK_LEFT 0x00008000
#define AV_CH_TOP_BACK_CENTER 0x00010000
#define AV_CH_TOP_BACK_RIGHT 0x00020000
#define AV_CH_STEREO_LEFT 0x20000000 ///< Stereo downmix.
#define AV_CH_STEREO_RIGHT 0x40000000 ///< See AV_CH_STEREO_LEFT.
#define AV_CH_WIDE_LEFT 0x0000000080000000ULL
#define AV_CH_WIDE_RIGHT 0x0000000100000000ULL
#define AV_CH_SURROUND_DIRECT_LEFT 0x0000000200000000ULL
#define AV_CH_SURROUND_DIRECT_RIGHT 0x0000000400000000ULL
#define AV_CH_LOW_FREQUENCY_2 0x0000000800000000ULL
#define AV_CH_TOP_SIDE_LEFT 0x0000001000000000ULL
#define AV_CH_TOP_SIDE_RIGHT 0x0000002000000000ULL
#define AV_CH_BOTTOM_FRONT_CENTER 0x0000004000000000ULL
#define AV_CH_BOTTOM_FRONT_LEFT 0x0000008000000000ULL
#define AV_CH_BOTTOM_FRONT_RIGHT 0x0000010000000000ULL
#define AV_CH_FRONT_LEFT (1ULL << AV_CHAN_FRONT_LEFT )
#define AV_CH_FRONT_RIGHT (1ULL << AV_CHAN_FRONT_RIGHT )
#define AV_CH_FRONT_CENTER (1ULL << AV_CHAN_FRONT_CENTER )
#define AV_CH_LOW_FREQUENCY (1ULL << AV_CHAN_LOW_FREQUENCY )
#define AV_CH_BACK_LEFT (1ULL << AV_CHAN_BACK_LEFT )
#define AV_CH_BACK_RIGHT (1ULL << AV_CHAN_BACK_RIGHT )
#define AV_CH_FRONT_LEFT_OF_CENTER (1ULL << AV_CHAN_FRONT_LEFT_OF_CENTER )
#define AV_CH_FRONT_RIGHT_OF_CENTER (1ULL << AV_CHAN_FRONT_RIGHT_OF_CENTER)
#define AV_CH_BACK_CENTER (1ULL << AV_CHAN_BACK_CENTER )
#define AV_CH_SIDE_LEFT (1ULL << AV_CHAN_SIDE_LEFT )
#define AV_CH_SIDE_RIGHT (1ULL << AV_CHAN_SIDE_RIGHT )
#define AV_CH_TOP_CENTER (1ULL << AV_CHAN_TOP_CENTER )
#define AV_CH_TOP_FRONT_LEFT (1ULL << AV_CHAN_TOP_FRONT_LEFT )
#define AV_CH_TOP_FRONT_CENTER (1ULL << AV_CHAN_TOP_FRONT_CENTER )
#define AV_CH_TOP_FRONT_RIGHT (1ULL << AV_CHAN_TOP_FRONT_RIGHT )
#define AV_CH_TOP_BACK_LEFT (1ULL << AV_CHAN_TOP_BACK_LEFT )
#define AV_CH_TOP_BACK_CENTER (1ULL << AV_CHAN_TOP_BACK_CENTER )
#define AV_CH_TOP_BACK_RIGHT (1ULL << AV_CHAN_TOP_BACK_RIGHT )
#define AV_CH_STEREO_LEFT (1ULL << AV_CHAN_STEREO_LEFT )
#define AV_CH_STEREO_RIGHT (1ULL << AV_CHAN_STEREO_RIGHT )
#define AV_CH_WIDE_LEFT (1ULL << AV_CHAN_WIDE_LEFT )
#define AV_CH_WIDE_RIGHT (1ULL << AV_CHAN_WIDE_RIGHT )
#define AV_CH_SURROUND_DIRECT_LEFT (1ULL << AV_CHAN_SURROUND_DIRECT_LEFT )
#define AV_CH_SURROUND_DIRECT_RIGHT (1ULL << AV_CHAN_SURROUND_DIRECT_RIGHT)
#define AV_CH_LOW_FREQUENCY_2 (1ULL << AV_CHAN_LOW_FREQUENCY_2 )
#define AV_CH_TOP_SIDE_LEFT (1ULL << AV_CHAN_TOP_SIDE_LEFT )
#define AV_CH_TOP_SIDE_RIGHT (1ULL << AV_CHAN_TOP_SIDE_RIGHT )
#define AV_CH_BOTTOM_FRONT_CENTER (1ULL << AV_CHAN_BOTTOM_FRONT_CENTER )
#define AV_CH_BOTTOM_FRONT_LEFT (1ULL << AV_CHAN_BOTTOM_FRONT_LEFT )
#define AV_CH_BOTTOM_FRONT_RIGHT (1ULL << AV_CHAN_BOTTOM_FRONT_RIGHT )
#if FF_API_OLD_CHANNEL_LAYOUT
/** Channel mask value used for AVCodecContext.request_channel_layout
to indicate that the user requests the channel order of the decoder output
to be the native codec channel order. */
to be the native codec channel order.
@deprecated channel order is now indicated in a special field in
AVChannelLayout
*/
#define AV_CH_LAYOUT_NATIVE 0x8000000000000000ULL
#endif
/**
* @}
@ -128,6 +202,141 @@ enum AVMatrixEncoding {
AV_MATRIX_ENCODING_NB
};
/**
* @}
*/
/**
* An AVChannelCustom defines a single channel within a custom order layout
*
* Unlike most structures in FFmpeg, sizeof(AVChannelCustom) is a part of the
* public ABI.
*
* No new fields may be added to it without a major version bump.
*/
typedef struct AVChannelCustom {
enum AVChannel id;
char name[16];
void *opaque;
} AVChannelCustom;
/**
* An AVChannelLayout holds information about the channel layout of audio data.
*
* A channel layout here is defined as a set of channels ordered in a specific
* way (unless the channel order is AV_CHANNEL_ORDER_UNSPEC, in which case an
* AVChannelLayout carries only the channel count).
*
* Unlike most structures in Libav, sizeof(AVChannelLayout) is a part of the
* public ABI and may be used by the caller. E.g. it may be allocated on stack
* or embedded in caller-defined structs.
*
* AVChannelLayout can be initialized as follows:
* - default initialization with {0}, followed by setting all used fields
* correctly;
* - by assigning one of the predefined AV_CHANNEL_LAYOUT_* initializers;
* - with a constructor function, such as av_channel_layout_default(),
* av_channel_layout_from_mask() or av_channel_layout_from_string().
*
* The channel layout must be unitialized with av_channel_layout_uninit()
*
* Copying an AVChannelLayout via assigning is forbidden,
* av_channel_layout_copy() must be used instead (and its return value should
* be checked)
*
* No new fields may be added to it without a major version bump, except for
* new elements of the union fitting in sizeof(uint64_t).
*/
typedef struct AVChannelLayout {
/**
* Channel order used in this layout.
* This is a mandatory field.
*/
enum AVChannelOrder order;
/**
* Number of channels in this layout. Mandatory field.
*/
int nb_channels;
/**
* Details about which channels are present in this layout.
* For AV_CHANNEL_ORDER_UNSPEC, this field is undefined and must not be
* used.
*/
union {
/**
* This member must be used for AV_CHANNEL_ORDER_NATIVE.
* It is a bitmask, where the position of each set bit means that the
* AVChannel with the corresponding value is present.
*
* I.e. when (mask & (1 << AV_CHAN_FOO)) is non-zero, then AV_CHAN_FOO
* is present in the layout. Otherwise it is not present.
*
* @note when a channel layout using a bitmask is constructed or
* modified manually (i.e. not using any of the av_channel_layout_*
* functions), the code doing it must ensure that the number of set bits
* is equal to nb_channels.
*/
uint64_t mask;
/**
* This member must be used when the channel order is
* AV_CHANNEL_ORDER_CUSTOM. It is a nb_channels-sized array, with each
* element signalling the presence of the AVChannel with the
* corresponding value in map[i].id.
*
* I.e. when map[i].id is equal to AV_CHAN_FOO, then AV_CH_FOO is the
* i-th channel in the audio data.
*
* map[i].name may be filled with a 0-terminated string, in which case
* it will be used for the purpose of identifying the channel with the
* convenience functions below. Otherise it must be zeroed.
*/
AVChannelCustom *map;
} u;
/**
* For some private data of the user.
*/
void *opaque;
} AVChannelLayout;
#define AV_CHANNEL_LAYOUT_MASK(nb, m) \
{ .order = AV_CHANNEL_ORDER_NATIVE, .nb_channels = (nb), .u = { .mask = (m) }}
#define AV_CHANNEL_LAYOUT_MONO AV_CHANNEL_LAYOUT_MASK(1, AV_CH_LAYOUT_MONO)
#define AV_CHANNEL_LAYOUT_STEREO AV_CHANNEL_LAYOUT_MASK(2, AV_CH_LAYOUT_STEREO)
#define AV_CHANNEL_LAYOUT_2POINT1 AV_CHANNEL_LAYOUT_MASK(3, AV_CH_LAYOUT_2POINT1)
#define AV_CHANNEL_LAYOUT_2_1 AV_CHANNEL_LAYOUT_MASK(3, AV_CH_LAYOUT_2_1)
#define AV_CHANNEL_LAYOUT_SURROUND AV_CHANNEL_LAYOUT_MASK(3, AV_CH_LAYOUT_SURROUND)
#define AV_CHANNEL_LAYOUT_3POINT1 AV_CHANNEL_LAYOUT_MASK(4, AV_CH_LAYOUT_3POINT1)
#define AV_CHANNEL_LAYOUT_4POINT0 AV_CHANNEL_LAYOUT_MASK(4, AV_CH_LAYOUT_4POINT0)
#define AV_CHANNEL_LAYOUT_4POINT1 AV_CHANNEL_LAYOUT_MASK(5, AV_CH_LAYOUT_4POINT1)
#define AV_CHANNEL_LAYOUT_2_2 AV_CHANNEL_LAYOUT_MASK(4, AV_CH_LAYOUT_2_2)
#define AV_CHANNEL_LAYOUT_QUAD AV_CHANNEL_LAYOUT_MASK(4, AV_CH_LAYOUT_QUAD)
#define AV_CHANNEL_LAYOUT_5POINT0 AV_CHANNEL_LAYOUT_MASK(5, AV_CH_LAYOUT_5POINT0)
#define AV_CHANNEL_LAYOUT_5POINT1 AV_CHANNEL_LAYOUT_MASK(6, AV_CH_LAYOUT_5POINT1)
#define AV_CHANNEL_LAYOUT_5POINT0_BACK AV_CHANNEL_LAYOUT_MASK(5, AV_CH_LAYOUT_5POINT0_BACK)
#define AV_CHANNEL_LAYOUT_5POINT1_BACK AV_CHANNEL_LAYOUT_MASK(6, AV_CH_LAYOUT_5POINT1_BACK)
#define AV_CHANNEL_LAYOUT_6POINT0 AV_CHANNEL_LAYOUT_MASK(6, AV_CH_LAYOUT_6POINT0)
#define AV_CHANNEL_LAYOUT_6POINT0_FRONT AV_CHANNEL_LAYOUT_MASK(6, AV_CH_LAYOUT_6POINT0_FRONT)
#define AV_CHANNEL_LAYOUT_HEXAGONAL AV_CHANNEL_LAYOUT_MASK(6, AV_CH_LAYOUT_HEXAGONAL)
#define AV_CHANNEL_LAYOUT_6POINT1 AV_CHANNEL_LAYOUT_MASK(7, AV_CH_LAYOUT_6POINT1)
#define AV_CHANNEL_LAYOUT_6POINT1_BACK AV_CHANNEL_LAYOUT_MASK(7, AV_CH_LAYOUT_6POINT1_BACK)
#define AV_CHANNEL_LAYOUT_6POINT1_FRONT AV_CHANNEL_LAYOUT_MASK(7, AV_CH_LAYOUT_6POINT1_FRONT)
#define AV_CHANNEL_LAYOUT_7POINT0 AV_CHANNEL_LAYOUT_MASK(7, AV_CH_LAYOUT_7POINT0)
#define AV_CHANNEL_LAYOUT_7POINT0_FRONT AV_CHANNEL_LAYOUT_MASK(7, AV_CH_LAYOUT_7POINT0_FRONT)
#define AV_CHANNEL_LAYOUT_7POINT1 AV_CHANNEL_LAYOUT_MASK(8, AV_CH_LAYOUT_7POINT1)
#define AV_CHANNEL_LAYOUT_7POINT1_WIDE AV_CHANNEL_LAYOUT_MASK(8, AV_CH_LAYOUT_7POINT1_WIDE)
#define AV_CHANNEL_LAYOUT_7POINT1_WIDE_BACK AV_CHANNEL_LAYOUT_MASK(8, AV_CH_LAYOUT_7POINT1_WIDE_BACK)
#define AV_CHANNEL_LAYOUT_OCTAGONAL AV_CHANNEL_LAYOUT_MASK(8, AV_CH_LAYOUT_OCTAGONAL)
#define AV_CHANNEL_LAYOUT_HEXADECAGONAL AV_CHANNEL_LAYOUT_MASK(16, AV_CH_LAYOUT_HEXADECAGONAL)
#define AV_CHANNEL_LAYOUT_STEREO_DOWNMIX AV_CHANNEL_LAYOUT_MASK(2, AV_CH_LAYOUT_STEREO_DOWNMIX)
#define AV_CHANNEL_LAYOUT_22POINT2 AV_CHANNEL_LAYOUT_MASK(24, AV_CH_LAYOUT_22POINT2)
struct AVBPrint;
#if FF_API_OLD_CHANNEL_LAYOUT
/**
* Return a channel layout id that matches name, or 0 if no match is found.
*
@ -144,7 +353,10 @@ enum AVMatrixEncoding {
* AV_CH_* macros).
*
* Example: "stereo+FC" = "2c+FC" = "2c+1c" = "0x7"
*
* @deprecated use av_channel_layout_from_string()
*/
attribute_deprecated
uint64_t av_get_channel_layout(const char *name);
/**
@ -158,7 +370,9 @@ uint64_t av_get_channel_layout(const char *name);
* @param[out] nb_channels number of channels
*
* @return 0 on success, AVERROR(EINVAL) if the parsing fails.
* @deprecated use av_channel_layout_from_string()
*/
attribute_deprecated
int av_get_extended_channel_layout(const char *name, uint64_t* channel_layout, int* nb_channels);
/**
@ -167,23 +381,31 @@ int av_get_extended_channel_layout(const char *name, uint64_t* channel_layout, i
*
* @param buf put here the string containing the channel layout
* @param buf_size size in bytes of the buffer
* @deprecated use av_channel_layout_describe()
*/
attribute_deprecated
void av_get_channel_layout_string(char *buf, int buf_size, int nb_channels, uint64_t channel_layout);
struct AVBPrint;
/**
* Append a description of a channel layout to a bprint buffer.
* @deprecated use av_channel_layout_describe()
*/
attribute_deprecated
void av_bprint_channel_layout(struct AVBPrint *bp, int nb_channels, uint64_t channel_layout);
/**
* Return the number of channels in the channel layout.
* @deprecated use AVChannelLayout.nb_channels
*/
attribute_deprecated
int av_get_channel_layout_nb_channels(uint64_t channel_layout);
/**
* Return default channel layout for a given number of channels.
*
* @deprecated use av_channel_layout_default()
*/
attribute_deprecated
int64_t av_get_default_channel_layout(int nb_channels);
/**
@ -194,20 +416,28 @@ int64_t av_get_default_channel_layout(int nb_channels);
*
* @return index of channel in channel_layout on success, a negative AVERROR
* on error.
*
* @deprecated use av_channel_layout_index_from_channel()
*/
attribute_deprecated
int av_get_channel_layout_channel_index(uint64_t channel_layout,
uint64_t channel);
/**
* Get the channel with the given index in channel_layout.
* @deprecated use av_channel_layout_channel_from_index()
*/
attribute_deprecated
uint64_t av_channel_layout_extract_channel(uint64_t channel_layout, int index);
/**
* Get the name of a given channel.
*
* @return channel name on success, NULL on error.
*
* @deprecated use av_channel_name()
*/
attribute_deprecated
const char *av_get_channel_name(uint64_t channel);
/**
@ -215,7 +445,9 @@ const char *av_get_channel_name(uint64_t channel);
*
* @param channel a channel layout with a single channel
* @return channel description on success, NULL on error
* @deprecated use av_channel_description()
*/
attribute_deprecated
const char *av_get_channel_description(uint64_t channel);
/**
@ -226,9 +458,238 @@ const char *av_get_channel_description(uint64_t channel);
* @param[out] name name of the layout
* @return 0 if the layout exists,
* <0 if index is beyond the limits
* @deprecated use av_channel_layout_standard()
*/
attribute_deprecated
int av_get_standard_channel_layout(unsigned index, uint64_t *layout,
const char **name);
#endif
/**
* Get a human readable string in an abbreviated form describing a given channel.
* This is the inverse function of @ref av_channel_from_string().
*
* @param buf pre-allocated buffer where to put the generated string
* @param buf_size size in bytes of the buffer.
* @return amount of bytes needed to hold the output string, or a negative AVERROR
* on failure. If the returned value is bigger than buf_size, then the
* string was truncated.
*/
int av_channel_name(char *buf, size_t buf_size, enum AVChannel channel);
/**
* bprint variant of av_channel_name().
*
* @note the string will be appended to the bprint buffer.
*/
void av_channel_name_bprint(struct AVBPrint *bp, enum AVChannel channel_id);
/**
* Get a human readable string describing a given channel.
*
* @param buf pre-allocated buffer where to put the generated string
* @param buf_size size in bytes of the buffer.
* @return amount of bytes needed to hold the output string, or a negative AVERROR
* on failure. If the returned value is bigger than buf_size, then the
* string was truncated.
*/
int av_channel_description(char *buf, size_t buf_size, enum AVChannel channel);
/**
* bprint variant of av_channel_description().
*
* @note the string will be appended to the bprint buffer.
*/
void av_channel_description_bprint(struct AVBPrint *bp, enum AVChannel channel_id);
/**
* This is the inverse function of @ref av_channel_name().
*
* @return the channel with the given name
* AV_CHAN_NONE when name does not identify a known channel
*/
enum AVChannel av_channel_from_string(const char *name);
/**
* Initialize a native channel layout from a bitmask indicating which channels
* are present.
*
* @param channel_layout the layout structure to be initialized
* @param mask bitmask describing the channel layout
*
* @return 0 on success
* AVERROR(EINVAL) for invalid mask values
*/
int av_channel_layout_from_mask(AVChannelLayout *channel_layout, uint64_t mask);
/**
* Initialize a channel layout from a given string description.
* The input string can be represented by:
* - the formal channel layout name (returned by av_channel_layout_describe())
* - single or multiple channel names (returned by av_channel_name(), eg. "FL",
* or concatenated with "+", each optionally containing a custom name after
* a "@", eg. "FL@Left+FR@Right+LFE")
* - a decimal or hexadecimal value of a native channel layout (eg. "4" or "0x4")
* - the number of channels with default layout (eg. "4c")
* - the number of unordered channels (eg. "4C" or "4 channels")
*
* @param channel_layout input channel layout
* @param str string describing the channel layout
* @return 0 channel layout was detected, AVERROR_INVALIDATATA otherwise
*/
int av_channel_layout_from_string(AVChannelLayout *channel_layout,
const char *str);
/**
* Get the default channel layout for a given number of channels.
*
* @param channel_layout the layout structure to be initialized
* @param nb_channels number of channels
*/
void av_channel_layout_default(AVChannelLayout *ch_layout, int nb_channels);
/**
* Iterate over all standard channel layouts.
*
* @param opaque a pointer where libavutil will store the iteration state. Must
* point to NULL to start the iteration.
*
* @return the standard channel layout or NULL when the iteration is
* finished
*/
const AVChannelLayout *av_channel_layout_standard(void **opaque);
/**
* Free any allocated data in the channel layout and reset the channel
* count to 0.
*
* @param channel_layout the layout structure to be uninitialized
*/
void av_channel_layout_uninit(AVChannelLayout *channel_layout);
/**
* Make a copy of a channel layout. This differs from just assigning src to dst
* in that it allocates and copies the map for AV_CHANNEL_ORDER_CUSTOM.
*
* @note the destination channel_layout will be always uninitialized before copy.
*
* @param dst destination channel layout
* @param src source channel layout
* @return 0 on success, a negative AVERROR on error.
*/
int av_channel_layout_copy(AVChannelLayout *dst, const AVChannelLayout *src);
/**
* Get a human-readable string describing the channel layout properties.
* The string will be in the same format that is accepted by
* @ref av_channel_layout_from_string(), allowing to rebuild the same
* channel layout, except for opaque pointers.
*
* @param channel_layout channel layout to be described
* @param buf pre-allocated buffer where to put the generated string
* @param buf_size size in bytes of the buffer.
* @return amount of bytes needed to hold the output string, or a negative AVERROR
* on failure. If the returned value is bigger than buf_size, then the
* string was truncated.
*/
int av_channel_layout_describe(const AVChannelLayout *channel_layout,
char *buf, size_t buf_size);
/**
* bprint variant of av_channel_layout_describe().
*
* @note the string will be appended to the bprint buffer.
* @return 0 on success, or a negative AVERROR value on failure.
*/
int av_channel_layout_describe_bprint(const AVChannelLayout *channel_layout,
struct AVBPrint *bp);
/**
* Get the channel with the given index in a channel layout.
*
* @param channel_layout input channel layout
* @return channel with the index idx in channel_layout on success or
* AV_CHAN_NONE on failure (if idx is not valid or the channel order is
* unspecified)
*/
enum AVChannel
av_channel_layout_channel_from_index(const AVChannelLayout *channel_layout, unsigned int idx);
/**
* Get the index of a given channel in a channel layout. In case multiple
* channels are found, only the first match will be returned.
*
* @param channel_layout input channel layout
* @return index of channel in channel_layout on success or a negative number if
* channel is not present in channel_layout.
*/
int av_channel_layout_index_from_channel(const AVChannelLayout *channel_layout,
enum AVChannel channel);
/**
* Get the index in a channel layout of a channel described by the given string.
* In case multiple channels are found, only the first match will be returned.
*
* This function accepts channel names in the same format as
* @ref av_channel_from_string().
*
* @param channel_layout input channel layout
* @return a channel index described by the given string, or a negative AVERROR
* value.
*/
int av_channel_layout_index_from_string(const AVChannelLayout *channel_layout,
const char *name);
/**
* Get a channel described by the given string.
*
* This function accepts channel names in the same format as
* @ref av_channel_from_string().
*
* @param channel_layout input channel layout
* @return a channel described by the given string in channel_layout on success
* or AV_CHAN_NONE on failure (if the string is not valid or the channel
* order is unspecified)
*/
enum AVChannel
av_channel_layout_channel_from_string(const AVChannelLayout *channel_layout,
const char *name);
/**
* Find out what channels from a given set are present in a channel layout,
* without regard for their positions.
*
* @param channel_layout input channel layout
* @param mask a combination of AV_CH_* representing a set of channels
* @return a bitfield representing all the channels from mask that are present
* in channel_layout
*/
uint64_t av_channel_layout_subset(const AVChannelLayout *channel_layout,
uint64_t mask);
/**
* Check whether a channel layout is valid, i.e. can possibly describe audio
* data.
*
* @param channel_layout input channel layout
* @return 1 if channel_layout is valid, 0 otherwise.
*/
int av_channel_layout_check(const AVChannelLayout *channel_layout);
/**
* Check whether two channel layouts are semantically the same, i.e. the same
* channels are present on the same positions in both.
*
* If one of the channel layouts is AV_CHANNEL_ORDER_UNSPEC, while the other is
* not, they are considered to be unequal. If both are AV_CHANNEL_ORDER_UNSPEC,
* they are considered equal iff the channel counts are the same in both.
*
* @param chl input channel layout
* @param chl1 input channel layout
* @return 0 if chl and chl1 are equal, 1 if they are not equal. A negative
* AVERROR code if one or both are invalid.
*/
int av_channel_layout_compare(const AVChannelLayout *chl, const AVChannelLayout *chl1);
/**
* @}

1
libavutil/version.h
Unescape View File

@ -112,6 +112,7 @@
#define FF_API_FIFO_PEEK2 (LIBAVUTIL_VERSION_MAJOR < 58)
#define FF_API_FIFO_OLD_API (LIBAVUTIL_VERSION_MAJOR < 58)
#define FF_API_XVMC (LIBAVUTIL_VERSION_MAJOR < 58)
#define FF_API_OLD_CHANNEL_LAYOUT (LIBAVUTIL_VERSION_MAJOR < 58)
/**
* @}

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