diff options
| -rw-r--r-- | src/send.c | 48 |
1 files changed, 43 insertions, 5 deletions
@@ -91,6 +91,40 @@ int send_byte(int c) return 0; } +int send_byte_with_ecc(int c) +{ + static int cs[4]; + static int ptr = 0; + int data[8]; + int i; + + if (c < 0) + while (ptr < 4) + cs[ptr++] = -c; + else + cs[ptr++] = c; + + if (ptr < 4) + return 0; + + ptr = 0; + + data[0] = cs[0] ^ cs[1] ^ cs[3]; + data[1] = cs[0] ^ cs[2] ^ cs[3]; + data[2] = cs[0]; + data[3] = cs[1] ^ cs[2] ^ cs[3]; + data[4] = cs[1]; + data[5] = cs[2]; + data[6] = cs[3]; + data[7] = cs[0] ^ cs[1] ^ cs[2] ^ cs[3]; + + for (i = 0; i < 8; i++) + if (send_byte(data[i])) + return -1; + + return 0; +} + int main(int argc, char* argv[]) { @@ -132,24 +166,28 @@ int main(int argc, char* argv[]) { c = buf[i]; if ((c == CHAR_ESCAPE) || (c == CHAR_CANCEL) || (c == CHAR_END)) - if (send_byte(CHAR_ESCAPE)) + if (send_byte_with_ecc(CHAR_ESCAPE)) goto snd_fail; - if (send_byte(c)) + if (send_byte_with_ecc(c)) goto snd_fail; } } - if (send_byte(CHAR_END)) + if (send_byte_with_ecc(CHAR_END)) + goto snd_fail; + if (send_byte_with_ecc(-CHAR_END)) goto snd_fail; snd_pcm_close(sound_handle); return 0; fail: perror(argv0); - send_byte(CHAR_CANCEL); + send_byte_with_ecc(CHAR_CANCEL); + send_byte_with_ecc(-CHAR_CANCEL); return 1; snd_fail: snd_pcm_close(sound_handle); - send_byte(CHAR_CANCEL); + send_byte_with_ecc(CHAR_CANCEL); + send_byte_with_ecc(-CHAR_CANCEL); return 1; } |