diff options
| -rw-r--r-- | libavcodec/mlp.c | 3 | ||||
| -rw-r--r-- | libavcodec/mlp.h | 8 | ||||
| -rw-r--r-- | libavcodec/mlpdec.c | 5 |
3 files changed, 10 insertions, 6 deletions
diff --git a/libavcodec/mlp.c b/libavcodec/mlp.c index f2a0276574..2ac2e658f1 100644 --- a/libavcodec/mlp.c +++ b/libavcodec/mlp.c @@ -110,8 +110,7 @@ uint8_t ff_mlp_calculate_parity(const uint8_t *buf, unsigned int buf_size) for (; buf < buf_end - 3; buf += 4) scratch ^= *((const uint32_t*)buf); - scratch ^= scratch >> 16; - scratch ^= scratch >> 8; + scratch = xor_32_to_8(scratch); for (; buf < buf_end; buf++) scratch ^= *buf; diff --git a/libavcodec/mlp.h b/libavcodec/mlp.h index dc6856727a..a434cd1a22 100644 --- a/libavcodec/mlp.h +++ b/libavcodec/mlp.h @@ -107,4 +107,12 @@ int ff_mlp_init_crc2D(AVCodecParserContext *s); void ff_mlp_init_crc(); +/** XOR four bytes into one. */ +static inline uint8_t xor_32_to_8(uint32_t value) +{ + value ^= value >> 16; + value ^= value >> 8; + return value; +} + #endif /* FFMPEG_MLP_H */ diff --git a/libavcodec/mlpdec.c b/libavcodec/mlpdec.c index d44c9b0b29..421abdece1 100644 --- a/libavcodec/mlpdec.c +++ b/libavcodec/mlpdec.c @@ -364,10 +364,7 @@ static int read_restart_header(MLPDecodeContext *m, GetBitContext *gbp, lossless_check = get_bits(gbp, 8); if (substr == m->max_decoded_substream && s->lossless_check_data != 0xffffffff) { - tmp = s->lossless_check_data; - tmp ^= tmp >> 16; - tmp ^= tmp >> 8; - tmp &= 0xff; + tmp = xor_32_to_8(s->lossless_check_data); if (tmp != lossless_check) av_log(m->avctx, AV_LOG_WARNING, "Lossless check failed - expected %02x, calculated %02x.\n", |