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Diffstat (limited to 'src/extensions.c')
| -rw-r--r-- | src/extensions.c | 288 |
1 files changed, 288 insertions, 0 deletions
diff --git a/src/extensions.c b/src/extensions.c new file mode 100644 index 00000000..b7bafb99 --- /dev/null +++ b/src/extensions.c @@ -0,0 +1,288 @@ +/* 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; + *header_size = 1; + do { + (*data)++; + len--; + if (len == 0) + return -1; + bytes += **data; + (*header_size)++; + } while (**data == 255); + (*data)++; + len--; + if (bytes <= len) + { + len -= bytes; + *data += bytes; + } else { + return -1; + } + + return len; + } + } +} + +/* Count the number of extensions, excluding real padding and separators. */ +opus_int32 opus_packet_extensions_count(const unsigned char *data, opus_int32 len) +{ + opus_int32 curr_len; + opus_int32 count=0; + const unsigned char *curr_data = data; + curr_len = len; + while (curr_len > 0) + { + int id; + opus_int32 header_size; + id = *curr_data>>1; + if (id > 1) + count++; + curr_len = skip_extension(&curr_data, curr_len, &header_size); + } + 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) +{ + const unsigned char *curr_data; + opus_int32 curr_len; + int curr_frame=0; + opus_int32 count=0; + + curr_data = data; + curr_len = len; + while (curr_len > 0) + { + int id; + opus_int32 header_size; + opus_extension_data curr_ext; + id = *curr_data>>1; + if (id > 1) + { + curr_ext.id = id; + curr_ext.frame = curr_frame; + curr_ext.data = curr_data; + } else if (id == 1) + { + int L = *curr_data&1; + if (L==0) + curr_frame++; + else { + if (curr_len >= 2) + curr_frame += curr_data[1]; + /* Else we're at the end and it doesn't matter. */ + } + if (curr_frame >= 48) + { + *nb_extensions = count; + return OPUS_INVALID_PACKET; + } + } + curr_len = skip_extension(&curr_data, curr_len, &header_size); + /* printf("curr_len = %d, header_size = %d\n", curr_len, header_size); */ + if (curr_len < 0) + { + *nb_extensions = count; + return OPUS_INVALID_PACKET; + } + celt_assert(curr_data - data == len - curr_len); + if (id > 1) + { + if (count == *nb_extensions) + { + return OPUS_BUFFER_TOO_SMALL; + } + curr_ext.len = curr_data - curr_ext.data - header_size; + curr_ext.data += header_size; + extensions[count++] = curr_ext; + } + } + celt_assert(curr_len == 0); + *nb_extensions = count; + return OPUS_OK; +} + +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; + for (i=0;i<nb_extensions;i++) + { + max_frame = IMAX(max_frame, extensions[i].frame); + if (extensions[i].id < 2) + 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) + data[pos++] = 0x02; + else { + data[pos++] = 0x03; + data[pos++] = diff; + } + 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; + data[pos++] = (extensions[i].id<<1) + extensions[i].len; + if (extensions[i].len > 0) + data[pos++] = extensions[i].data[0]; + } else { + int last; + opus_int32 length_bytes; + 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; + data[pos++] = (extensions[i].id<<1) + !last; + if (!last) + { + opus_int32 j; + for (j=0;j<extensions[i].len/255;j++) + data[pos++] = 255; + data[pos++] = extensions[i].len % 255; + } + 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; + 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 |