ref: 6dabc64aea921626a7f0a7f3b4dd4a00e7a32b7f
dir: /src/extensions.c/
/* Copyright (c) 2022 Amazon */
/*
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
- Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
- Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "opus_types.h"
#include "opus_defines.h"
#include "arch.h"
#include "os_support.h"
#include "opus_private.h"
/* Given an extension payload, advance data to the next extension and return the
length of the remaining extensions. */
static opus_int32 skip_extension(const unsigned char **data, opus_int32 len,
opus_int32 *header_size)
{
int id, L;
if (len==0)
return 0;
id = **data>>1;
L = **data&1;
if (id == 0 && L == 1)
{
*header_size = 1;
if (len < 1)
return -1;
(*data)++;
len--;
return len;
} else if (id > 0 && id < 32)
{
if (len < 1+L)
return -1;
*data += 1+L;
len -= 1+L;
*header_size = 1;
return len;
} else {
if (L==0)
{
*data += len;
*header_size = 1;
return 0;
} else {
opus_int32 bytes=0;
opus_int32 lacing;
*header_size = 1;
do {
(*data)++;
len--;
if (len < 1)
return -1;
lacing = **data;
bytes += lacing;
(*header_size)++;
len -= lacing;
} while (lacing == 255);
if (len < 1)
return -1;
(*data)++;
len--;
*data += bytes;
return len;
}
}
}
void opus_extension_iterator_init(OpusExtensionIterator *iter,
const unsigned char *data, opus_int32 len) {
celt_assert(len >= 0);
celt_assert(data != NULL || len == 0);
iter->curr_data = iter->data = data;
iter->curr_len = iter->len = len;
iter->curr_frame = 0;
}
/* Reset the iterator so it can start iterating again from the first
extension. */
void opus_extension_iterator_reset(OpusExtensionIterator *iter) {
iter->curr_data = iter->data;
iter->curr_len = iter->len;
iter->curr_frame = 0;
}
/* Return the next extension (excluding real padding and separators). */
int opus_extension_iterator_next(OpusExtensionIterator *iter,
opus_extension_data *ext) {
opus_int32 header_size;
if (iter->curr_len < 0) {
return OPUS_INVALID_PACKET;
}
while (iter->curr_len > 0) {
const unsigned char *curr_data0;
int id;
int L;
curr_data0 = iter->curr_data;
id = *curr_data0>>1;
L = *curr_data0&1;
iter->curr_len = skip_extension(&iter->curr_data, iter->curr_len,
&header_size);
if (iter->curr_len < 0) {
return OPUS_INVALID_PACKET;
}
celt_assert(iter->curr_data - iter->data == iter->len - iter->curr_len);
if (id == 1) {
if (L == 0) {
iter->curr_frame++;
}
else {
iter->curr_frame += curr_data0[1];
}
if (iter->curr_frame >= 48) {
iter->curr_len = -1;
return OPUS_INVALID_PACKET;
}
}
else if (id > 1) {
if (ext != NULL) {
ext->id = id;
ext->frame = iter->curr_frame;
ext->data = curr_data0 + header_size;
ext->len = iter->curr_data - curr_data0 - header_size;
}
return 1;
}
}
return 0;
}
int opus_extension_iterator_find(OpusExtensionIterator *iter,
opus_extension_data *ext, int id) {
opus_extension_data curr_ext;
int ret;
for(;;) {
ret = opus_extension_iterator_next(iter, &curr_ext);
if (ret <= 0) {
return ret;
}
if (curr_ext.id == id) {
*ext = curr_ext;
return ret;
}
}
}
/* Count the number of extensions, excluding real padding and separators. */
opus_int32 opus_packet_extensions_count(const unsigned char *data, opus_int32 len)
{
OpusExtensionIterator iter;
int count;
opus_extension_iterator_init(&iter, data, len);
for (count=0; opus_extension_iterator_next(&iter, NULL) > 0; count++);
return count;
}
/* Extract extensions from Opus padding (excluding real padding and separators) */
opus_int32 opus_packet_extensions_parse(const unsigned char *data, opus_int32 len, opus_extension_data *extensions, opus_int32 *nb_extensions)
{
OpusExtensionIterator iter;
int count;
int ret;
celt_assert(nb_extensions != NULL);
celt_assert(extensions != NULL || *nb_extensions == 0);
opus_extension_iterator_init(&iter, data, len);
for (count=0;; count++) {
opus_extension_data ext;
ret = opus_extension_iterator_next(&iter, &ext);
if (ret <= 0) break;
if (count == *nb_extensions) {
return OPUS_BUFFER_TOO_SMALL;
}
extensions[count] = ext;
}
*nb_extensions = count;
return ret;
}
opus_int32 opus_packet_extensions_generate(unsigned char *data, opus_int32 len, const opus_extension_data *extensions, opus_int32 nb_extensions, int pad)
{
int max_frame=0;
opus_int32 i;
int frame;
int curr_frame = 0;
opus_int32 pos = 0;
opus_int32 written = 0;
celt_assert(len >= 0);
for (i=0;i<nb_extensions;i++)
{
max_frame = IMAX(max_frame, extensions[i].frame);
if (extensions[i].id < 2 || extensions[i].id > 127)
return OPUS_BAD_ARG;
}
if (max_frame >= 48) return OPUS_BAD_ARG;
for (frame=0;frame<=max_frame;frame++)
{
for (i=0;i<nb_extensions;i++)
{
if (extensions[i].frame == frame)
{
/* Insert separator when needed. */
if (frame != curr_frame) {
int diff = frame - curr_frame;
if (len-pos < 2)
return OPUS_BUFFER_TOO_SMALL;
if (diff == 1) {
if (data) data[pos] = 0x02;
pos++;
} else {
if (data) data[pos] = 0x03;
pos++;
if (data) data[pos] = diff;
pos++;
}
curr_frame = frame;
}
if (extensions[i].id < 32)
{
if (extensions[i].len < 0 || extensions[i].len > 1)
return OPUS_BAD_ARG;
if (len-pos < extensions[i].len+1)
return OPUS_BUFFER_TOO_SMALL;
if (data) data[pos] = (extensions[i].id<<1) + extensions[i].len;
pos++;
if (extensions[i].len > 0) {
if (data) data[pos] = extensions[i].data[0];
pos++;
}
} else {
int last;
opus_int32 length_bytes;
if (extensions[i].len < 0)
return OPUS_BAD_ARG;
last = (written == nb_extensions - 1);
length_bytes = 1 + extensions[i].len/255;
if (last)
length_bytes = 0;
if (len-pos < 1 + length_bytes + extensions[i].len)
return OPUS_BUFFER_TOO_SMALL;
if (data) data[pos] = (extensions[i].id<<1) + !last;
pos++;
if (!last)
{
opus_int32 j;
for (j=0;j<extensions[i].len/255;j++) {
if (data) data[pos] = 255;
pos++;
}
if (data) data[pos] = extensions[i].len % 255;
pos++;
}
if (data) OPUS_COPY(&data[pos], extensions[i].data, extensions[i].len);
pos += extensions[i].len;
}
written++;
}
}
}
/* If we need to pad, just prepend 0x01 bytes. Even better would be to fill the
end with zeros, but that requires checking that turning the last extesion into
an L=1 case still fits. */
if (pad && pos < len)
{
opus_int32 padding = len - pos;
if (data) {
OPUS_MOVE(data+padding, data, pos);
for (i=0;i<padding;i++)
data[i] = 0x01;
}
pos += padding;
}
return pos;
}
#if 0
#include <stdio.h>
int main()
{
opus_extension_data ext[] = {{2, 0, (const unsigned char *)"a", 1},
{32, 10, (const unsigned char *)"DRED", 4},
{33, 1, (const unsigned char *)"NOT DRED", 8},
{3, 4, (const unsigned char *)NULL, 0}
};
opus_extension_data ext2[10];
int i, len;
int nb_ext = 10;
unsigned char packet[10000];
len = opus_packet_extensions_generate(packet, 32, ext, 4, 1);
for (i=0;i<len;i++)
{
printf("%#04x ", packet[i]);
if (i%16 == 15)
printf("\n");
}
printf("\n");
printf("count = %d\n", opus_packet_extensions_count(packet, len));
opus_packet_extensions_parse(packet, len, ext2, &nb_ext);
for (i=0;i<nb_ext;i++)
{
int j;
printf("%d %d {", ext2[i].id, ext2[i].frame);
for (j=0;j<ext2[i].len;j++) printf("%#04x ", ext2[i].data[j]);
printf("} %d\n", ext2[i].len);
}
}
#endif