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FFmpeg/libavutil/channel_layout.c
Andreas Rheinhardt c4f35ba808 avutil/channel_layout: Account for \0 in sizes
av_channel_name(), av_channel_description() and
av_channel_layout_describe() are supposed to return the size
of the needed buffer to allow the user to check for truncation;
the documentation ("If the returned value is bigger than buf_size,
then the string was truncated.") confirms that size does not
mean strlen.

Yet the AVBPrint API, i.e. AVBPrint.len, does not account for
the terminating '\0'. Therefore the returned length is off by one.

Furthermore, also check for whether the returned value actually
fits in an int (which is the return value of these functions).

Reviewed-by: Nicolas George <george@nsup.org>
Reviewed-by: James Almer <jamrial@gmail.com>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
2023-08-10 08:55:05 +02:00

1013 lines
34 KiB
C

/*
* Copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* audio channel layout utility functions
*/
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include "avassert.h"
#include "channel_layout.h"
#include "bprint.h"
#include "common.h"
#include "error.h"
#include "macros.h"
#include "opt.h"
#define CHAN_IS_AMBI(x) ((x) >= AV_CHAN_AMBISONIC_BASE &&\
(x) <= AV_CHAN_AMBISONIC_END)
struct channel_name {
const char *name;
const char *description;
};
static const struct channel_name channel_names[] = {
[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(enum AVChannel channel_id)
{
if ((unsigned) channel_id >= FF_ARRAY_ELEMS(channel_names) ||
!channel_names[channel_id].name)
return NULL;
return channel_names[channel_id].name;
}
void av_channel_name_bprint(AVBPrint *bp, enum AVChannel channel_id)
{
if (channel_id >= AV_CHAN_AMBISONIC_BASE &&
channel_id <= AV_CHAN_AMBISONIC_END)
av_bprintf(bp, "AMBI%d", channel_id - AV_CHAN_AMBISONIC_BASE);
else if ((unsigned)channel_id < FF_ARRAY_ELEMS(channel_names) &&
channel_names[channel_id].name)
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);
if (bp.len >= INT_MAX)
return AVERROR(ERANGE);
return bp.len + 1;
}
void av_channel_description_bprint(AVBPrint *bp, enum AVChannel channel_id)
{
if (channel_id >= AV_CHAN_AMBISONIC_BASE &&
channel_id <= AV_CHAN_AMBISONIC_END)
av_bprintf(bp, "ambisonic ACN %d", channel_id - AV_CHAN_AMBISONIC_BASE);
else if ((unsigned)channel_id < FF_ARRAY_ELEMS(channel_names) &&
channel_names[channel_id].description)
av_bprintf(bp, "%s", channel_names[channel_id].description);
else if (channel_id == AV_CHAN_NONE)
av_bprintf(bp, "none");
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);
if (bp.len >= INT_MAX)
return AVERROR(ERANGE);
return bp.len + 1;
}
enum AVChannel av_channel_from_string(const char *str)
{
int i;
char *endptr = (char *)str;
enum AVChannel id = AV_CHAN_NONE;
if (!strncmp(str, "AMBI", 4)) {
i = strtol(str + 4, NULL, 0);
if (i < 0 || i > AV_CHAN_AMBISONIC_END - AV_CHAN_AMBISONIC_BASE)
return AV_CHAN_NONE;
return AV_CHAN_AMBISONIC_BASE + i;
}
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;
AVChannelLayout layout;
};
static const struct channel_layout_name channel_layout_map[] = {
{ "mono", AV_CHANNEL_LAYOUT_MONO },
{ "stereo", AV_CHANNEL_LAYOUT_STEREO },
{ "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 },
{ "7.1(top)", AV_CHANNEL_LAYOUT_7POINT1_TOP_BACK },
{ "octagonal", AV_CHANNEL_LAYOUT_OCTAGONAL },
{ "cube", AV_CHANNEL_LAYOUT_CUBE },
{ "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;
char *end;
int64_t layout;
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.u.mask;
}
for (i = 0; i < FF_ARRAY_ELEMS(channel_names); i++)
if (channel_names[i].name &&
strlen(channel_names[i].name) == name_len &&
!memcmp(channel_names[i].name, name, name_len))
return (int64_t)1 << i;
errno = 0;
i = strtol(name, &end, 10);
if (!errno && (end + 1 - name == name_len && *end == 'c'))
return av_get_default_channel_layout(i);
errno = 0;
layout = strtoll(name, &end, 0);
if (!errno && end - name == name_len)
return FFMAX(layout, 0);
return 0;
}
uint64_t av_get_channel_layout(const char *name)
{
const char *n, *e;
const char *name_end = name + strlen(name);
int64_t layout = 0, layout_single;
for (n = name; n < name_end; n = e + 1) {
for (e = n; e < name_end && *e != '+' && *e != '|'; e++);
layout_single = get_channel_layout_single(n, e - n);
if (!layout_single)
return 0;
layout |= layout_single;
}
return layout;
}
int av_get_extended_channel_layout(const char *name, uint64_t* channel_layout, int* nb_channels)
{
int nb = 0;
char *end;
uint64_t layout = av_get_channel_layout(name);
if (layout) {
*channel_layout = layout;
*nb_channels = av_get_channel_layout_nb_channels(layout);
return 0;
}
nb = strtol(name, &end, 10);
if (!errno && *end == 'C' && *(end + 1) == '\0' && nb > 0 && nb < 64) {
*channel_layout = 0;
*nb_channels = nb;
return 0;
}
return AVERROR(EINVAL);
}
void av_bprint_channel_layout(struct AVBPrint *bp,
int nb_channels, uint64_t channel_layout)
{
int i;
if (nb_channels <= 0)
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].layout.nb_channels &&
channel_layout == channel_layout_map[i].layout.u.mask) {
av_bprintf(bp, "%s", channel_layout_map[i].name);
return;
}
av_bprintf(bp, "%d channels", nb_channels);
if (channel_layout) {
int i, ch;
av_bprintf(bp, " (");
for (i = 0, ch = 0; i < 64; i++) {
if ((channel_layout & (UINT64_C(1) << i))) {
const char *name = get_channel_name(i);
if (name) {
if (ch > 0)
av_bprintf(bp, "+");
av_bprintf(bp, "%s", name);
}
ch++;
}
}
av_bprintf(bp, ")");
}
}
void av_get_channel_layout_string(char *buf, int buf_size,
int nb_channels, uint64_t channel_layout)
{
AVBPrint bp;
av_bprint_init_for_buffer(&bp, buf, buf_size);
av_bprint_channel_layout(&bp, nb_channels, channel_layout);
}
int av_get_channel_layout_nb_channels(uint64_t channel_layout)
{
return av_popcount64(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].layout.nb_channels)
return channel_layout_map[i].layout.u.mask;
return 0;
}
int av_get_channel_layout_channel_index(uint64_t channel_layout,
uint64_t channel)
{
if (!(channel_layout & channel) ||
av_get_channel_layout_nb_channels(channel) != 1)
return AVERROR(EINVAL);
channel_layout &= channel - 1;
return av_get_channel_layout_nb_channels(channel_layout);
}
const char *av_get_channel_name(uint64_t channel)
{
int i;
if (av_get_channel_layout_nb_channels(channel) != 1)
return NULL;
for (i = 0; i < 64; i++)
if ((1ULL<<i) & channel)
return get_channel_name(i);
return NULL;
}
const char *av_get_channel_description(uint64_t channel)
{
int i;
if (av_get_channel_layout_nb_channels(channel) != 1)
return NULL;
for (i = 0; i < FF_ARRAY_ELEMS(channel_names); i++)
if ((1ULL<<i) & channel)
return channel_names[i].description;
return NULL;
}
uint64_t av_channel_layout_extract_channel(uint64_t channel_layout, int index)
{
int i;
if (av_get_channel_layout_nb_channels(channel_layout) <= index)
return 0;
for (i = 0; i < 64; i++) {
if ((1ULL << i) & channel_layout && !index--)
return 1ULL << i;
}
return 0;
}
int av_get_standard_channel_layout(unsigned index, uint64_t *layout,
const char **name)
{
if (index >= FF_ARRAY_ELEMS(channel_layout_map))
return AVERROR_EOF;
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;
}
}
/* ambisonic */
if (!strncmp(str, "ambisonic ", 10)) {
const char *p = str + 10;
char *endptr;
AVChannelLayout extra = {0};
int order;
order = strtol(p, &endptr, 0);
if (order < 0 || order + 1 > INT_MAX / (order + 1) ||
(*endptr && *endptr != '+'))
return AVERROR(EINVAL);
channel_layout->order = AV_CHANNEL_ORDER_AMBISONIC;
channel_layout->nb_channels = (order + 1) * (order + 1);
if (*endptr) {
int ret = av_channel_layout_from_string(&extra, endptr + 1);
if (ret < 0)
return ret;
if (extra.nb_channels >= INT_MAX - channel_layout->nb_channels) {
av_channel_layout_uninit(&extra);
return AVERROR(EINVAL);
}
if (extra.order == AV_CHANNEL_ORDER_NATIVE) {
channel_layout->u.mask = extra.u.mask;
} else {
channel_layout->order = AV_CHANNEL_ORDER_CUSTOM;
channel_layout->u.map =
av_calloc(channel_layout->nb_channels + extra.nb_channels,
sizeof(*channel_layout->u.map));
if (!channel_layout->u.map) {
av_channel_layout_uninit(&extra);
return AVERROR(ENOMEM);
}
for (i = 0; i < channel_layout->nb_channels; i++)
channel_layout->u.map[i].id = AV_CHAN_AMBISONIC_BASE + i;
for (i = 0; i < extra.nb_channels; i++) {
enum AVChannel ch = av_channel_layout_channel_from_index(&extra, i);
if (CHAN_IS_AMBI(ch)) {
av_channel_layout_uninit(&extra);
return AVERROR(EINVAL);
}
channel_layout->u.map[channel_layout->nb_channels + i].id = ch;
if (extra.order == AV_CHANNEL_ORDER_CUSTOM &&
extra.u.map[i].name[0])
av_strlcpy(channel_layout->u.map[channel_layout->nb_channels + i].name,
extra.u.map[i].name,
sizeof(channel_layout->u.map[channel_layout->nb_channels + i].name));
}
}
channel_layout->nb_channels += extra.nb_channels;
av_channel_layout_uninit(&extra);
}
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);
}
av_free(chlist);
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;
}
/**
* If the layout is n-th order standard-order ambisonic, with optional
* extra non-diegetic channels at the end, return the order.
* Return a negative error code otherwise.
*/
static int ambisonic_order(const AVChannelLayout *channel_layout)
{
int i, highest_ambi, order;
highest_ambi = -1;
if (channel_layout->order == AV_CHANNEL_ORDER_AMBISONIC)
highest_ambi = channel_layout->nb_channels - av_popcount64(channel_layout->u.mask) - 1;
else {
const AVChannelCustom *map = channel_layout->u.map;
av_assert0(channel_layout->order == AV_CHANNEL_ORDER_CUSTOM);
for (i = 0; i < channel_layout->nb_channels; i++) {
int is_ambi = CHAN_IS_AMBI(map[i].id);
/* ambisonic following non-ambisonic */
if (i > 0 && is_ambi && !CHAN_IS_AMBI(map[i - 1].id))
return AVERROR(EINVAL);
/* non-default ordering */
if (is_ambi && map[i].id - AV_CHAN_AMBISONIC_BASE != i)
return AVERROR(EINVAL);
if (CHAN_IS_AMBI(map[i].id))
highest_ambi = i;
}
}
/* no ambisonic channels*/
if (highest_ambi < 0)
return AVERROR(EINVAL);
order = floor(sqrt(highest_ambi));
/* incomplete order - some harmonics are missing */
if ((order + 1) * (order + 1) != highest_ambi + 1)
return AVERROR(EINVAL);
return order;
}
/**
* If the custom layout is n-th order standard-order ambisonic, with optional
* extra non-diegetic channels at the end, write its string description in bp.
* Return a negative error code otherwise.
*/
static int try_describe_ambisonic(AVBPrint *bp, const AVChannelLayout *channel_layout)
{
int nb_ambi_channels;
int order = ambisonic_order(channel_layout);
if (order < 0)
return order;
av_bprintf(bp, "ambisonic %d", order);
/* extra channels present */
nb_ambi_channels = (order + 1) * (order + 1);
if (nb_ambi_channels < channel_layout->nb_channels) {
AVChannelLayout extra = { 0 };
if (channel_layout->order == AV_CHANNEL_ORDER_AMBISONIC) {
extra.order = AV_CHANNEL_ORDER_NATIVE;
extra.nb_channels = av_popcount64(channel_layout->u.mask);
extra.u.mask = channel_layout->u.mask;
} else {
extra.order = AV_CHANNEL_ORDER_CUSTOM;
extra.nb_channels = channel_layout->nb_channels - nb_ambi_channels;
extra.u.map = channel_layout->u.map + nb_ambi_channels;
}
av_bprint_chars(bp, '+', 1);
av_channel_layout_describe_bprint(&extra, bp);
/* Not calling uninit here on extra because we don't own the u.map pointer */
}
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->order == AV_CHANNEL_ORDER_CUSTOM) {
int res = try_describe_ambisonic(bp, channel_layout);
if (res >= 0)
return 0;
}
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);
if (i)
av_bprintf(bp, "+");
av_channel_name_bprint(bp, 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;
case AV_CHANNEL_ORDER_AMBISONIC:
return try_describe_ambisonic(bp, channel_layout);
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;
if (bp.len >= INT_MAX)
return AVERROR(ERANGE);
return bp.len + 1;
}
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_AMBISONIC: {
int ambi_channels = channel_layout->nb_channels - av_popcount64(channel_layout->u.mask);
if (idx < ambi_channels)
return AV_CHAN_AMBISONIC_BASE + idx;
idx -= ambi_channels;
}
// fall-through
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_AMBISONIC:
case AV_CHANNEL_ORDER_NATIVE: {
uint64_t mask = channel_layout->u.mask;
int ambi_channels = channel_layout->nb_channels - av_popcount64(mask);
if (channel_layout->order == AV_CHANNEL_ORDER_AMBISONIC &&
channel >= AV_CHAN_AMBISONIC_BASE) {
if (channel - AV_CHAN_AMBISONIC_BASE >= ambi_channels)
return AVERROR(EINVAL);
return channel - AV_CHAN_AMBISONIC_BASE;
}
if ((unsigned)channel > 63 || !(mask & (1ULL << channel)))
return AVERROR(EINVAL);
mask &= (1ULL << channel) - 1;
return av_popcount64(mask) + ambi_channels;
}
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_AMBISONIC:
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_AMBISONIC:
/* If non-diegetic channels are present, ensure they are taken into account */
return av_popcount64(channel_layout->u.mask) < channel_layout->nb_channels;
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_NATIVE ||
chl->order == AV_CHANNEL_ORDER_AMBISONIC) &&
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;
switch (channel_layout->order) {
case AV_CHANNEL_ORDER_NATIVE:
case AV_CHANNEL_ORDER_AMBISONIC:
return channel_layout->u.mask & mask;
case AV_CHANNEL_ORDER_CUSTOM:
for (i = 0; i < 64; i++)
if (mask & (1ULL << i) && av_channel_layout_index_from_channel(channel_layout, i) >= 0)
ret |= (1ULL << i);
break;
}
return ret;
}