sbc: ensure 16-byte buffer position alignment for 4 subbands encoding

Buffer position in X array was not always 16-bytes aligned.
Strict 16-byte alignment is strictly required for powerpc altivec
simd optimizations because altivec does not have support for
unaligned vector loads at all.

diff --git a/sbc/sbc.c b/sbc/sbc.c
index 1510adc..b251d50 100644 (file)
--- a/sbc/sbc.c
+++ b/sbc/sbc.c
@@ -924,7 +924,7 @@ static void sbc_encoder_init(struct sbc_encoder_state *state,
                                const struct sbc_frame *frame)
 {
        memset(&state->X, 0, sizeof(state->X));
-       state->position = SBC_X_BUFFER_SIZE - frame->subbands * 9;
+       state->position = (SBC_X_BUFFER_SIZE - frame->subbands * 9) & ~7;
 
        sbc_init_primitives(state);
 }

diff --git a/sbc/sbc_primitives.c b/sbc/sbc_primitives.c
index 6b0be3f..2105280 100644 (file)
--- a/sbc/sbc_primitives.c
+++ b/sbc/sbc_primitives.c
@@ -231,12 +231,12 @@ static SBC_ALWAYS_INLINE int sbc_encoder_process_input_s4_internal(
        /* handle X buffer wraparound */
        if (position < nsamples) {
                if (nchannels > 0)
-                       memcpy(&X[0][SBC_X_BUFFER_SIZE - 36], &X[0][position],
+                       memcpy(&X[0][SBC_X_BUFFER_SIZE - 40], &X[0][position],
                                                        36 * sizeof(int16_t));
                if (nchannels > 1)
-                       memcpy(&X[1][SBC_X_BUFFER_SIZE - 36], &X[1][position],
+                       memcpy(&X[1][SBC_X_BUFFER_SIZE - 40], &X[1][position],
                                                        36 * sizeof(int16_t));
-               position = SBC_X_BUFFER_SIZE - 36;
+               position = SBC_X_BUFFER_SIZE - 40;
        }
 
        #define PCM(i) (big_endian ? \