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authorSiarhei Siamashka <siarhei.siamashka@nokia.com>2011-03-14 15:16:30 -0300
committerLuiz Augusto von Dentz <luiz.dentz-von@nokia.com>2011-03-14 15:16:30 -0300
commitc2b2fc1640b380b5bb17960975ae6b21c3f8de2d (patch)
tree97bba29ca93d2b2259c6cad5bcb68a59dff4ba67 /src
parent16a05e52c635e192eb878ec5b3a87e3e00d91aed (diff)
sbc: new 'sbc_calc_scalefactors_j' function added to sbc primitives
The code for scale factors calculation with joint stereo support has been moved to a separate function. It can get platform-specific SIMD optimizations later for best possible performance. But even this change in C code improves performance because of the use of __builtin_clz() instead of loops similar to what was done to sbc_calc_scalefactors earlier. Also technically it does loop unrolling by processing two channels at once, which might be either good or bad for performance (if the registers pressure is increased and more data is spilled to memory). But the benchmark from 32-bit x86 system (pentium-m) shows that it got clearly faster: $ time ./sbcenc.old -b53 -s8 -j test.au > /dev/null real 0m1.868s user 0m1.808s sys 0m0.048s $ time ./sbcenc.new -b53 -s8 -j test.au > /dev/null real 0m1.742s user 0m1.668s sys 0m0.064s
Diffstat (limited to 'src')
-rw-r--r--src/modules/bluetooth/sbc/sbc.c91
-rw-r--r--src/modules/bluetooth/sbc/sbc_primitives.c75
-rw-r--r--src/modules/bluetooth/sbc/sbc_primitives.h4
3 files changed, 102 insertions, 68 deletions
diff --git a/src/modules/bluetooth/sbc/sbc.c b/src/modules/bluetooth/sbc/sbc.c
index 5c5c1112..512341fa 100644
--- a/src/modules/bluetooth/sbc/sbc.c
+++ b/src/modules/bluetooth/sbc/sbc.c
@@ -744,7 +744,7 @@ static int sbc_analyze_audio(struct sbc_encoder_state *state,
static SBC_ALWAYS_INLINE int sbc_pack_frame_internal(
uint8_t *data, struct sbc_frame *frame, size_t len,
- int frame_subbands, int frame_channels)
+ int frame_subbands, int frame_channels, int joint)
{
/* Bitstream writer starts from the fourth byte */
uint8_t *data_ptr = data + 4;
@@ -801,63 +801,6 @@ static SBC_ALWAYS_INLINE int sbc_pack_frame_internal(
crc_pos = 16;
if (frame->mode == JOINT_STEREO) {
- /* like frame->sb_sample but joint stereo */
- int32_t sb_sample_j[16][2];
- /* scalefactor and scale_factor in joint case */
- uint32_t scalefactor_j[2];
- uint8_t scale_factor_j[2];
-
- uint8_t joint = 0;
- frame->joint = 0;
-
- for (sb = 0; sb < frame_subbands - 1; sb++) {
- scale_factor_j[0] = 0;
- scalefactor_j[0] = 2 << SCALE_OUT_BITS;
- scale_factor_j[1] = 0;
- scalefactor_j[1] = 2 << SCALE_OUT_BITS;
-
- for (blk = 0; blk < frame->blocks; blk++) {
- uint32_t tmp;
- /* Calculate joint stereo signal */
- sb_sample_j[blk][0] =
- ASR(frame->sb_sample_f[blk][0][sb], 1) +
- ASR(frame->sb_sample_f[blk][1][sb], 1);
- sb_sample_j[blk][1] =
- ASR(frame->sb_sample_f[blk][0][sb], 1) -
- ASR(frame->sb_sample_f[blk][1][sb], 1);
-
- /* calculate scale_factor_j and scalefactor_j for joint case */
- tmp = fabs(sb_sample_j[blk][0]);
- while (scalefactor_j[0] < tmp) {
- scale_factor_j[0]++;
- scalefactor_j[0] *= 2;
- }
- tmp = fabs(sb_sample_j[blk][1]);
- while (scalefactor_j[1] < tmp) {
- scale_factor_j[1]++;
- scalefactor_j[1] *= 2;
- }
- }
-
- /* decide whether to join this subband */
- if ((frame->scale_factor[0][sb] +
- frame->scale_factor[1][sb]) >
- (scale_factor_j[0] +
- scale_factor_j[1])) {
- /* use joint stereo for this subband */
- joint |= 1 << (frame_subbands - 1 - sb);
- frame->joint |= 1 << sb;
- frame->scale_factor[0][sb] = scale_factor_j[0];
- frame->scale_factor[1][sb] = scale_factor_j[1];
- for (blk = 0; blk < frame->blocks; blk++) {
- frame->sb_sample_f[blk][0][sb] =
- sb_sample_j[blk][0];
- frame->sb_sample_f[blk][1][sb] =
- sb_sample_j[blk][1];
- }
- }
- }
-
PUT_BITS(data_ptr, bits_cache, bits_count,
joint, frame_subbands);
crc_header[crc_pos >> 3] = joint;
@@ -915,18 +858,23 @@ static SBC_ALWAYS_INLINE int sbc_pack_frame_internal(
return data_ptr - data;
}
-static int sbc_pack_frame(uint8_t *data, struct sbc_frame *frame, size_t len)
+static int sbc_pack_frame(uint8_t *data, struct sbc_frame *frame, size_t len,
+ int joint)
{
if (frame->subbands == 4) {
if (frame->channels == 1)
- return sbc_pack_frame_internal(data, frame, len, 4, 1);
+ return sbc_pack_frame_internal(
+ data, frame, len, 4, 1, joint);
else
- return sbc_pack_frame_internal(data, frame, len, 4, 2);
+ return sbc_pack_frame_internal(
+ data, frame, len, 4, 2, joint);
} else {
if (frame->channels == 1)
- return sbc_pack_frame_internal(data, frame, len, 8, 1);
+ return sbc_pack_frame_internal(
+ data, frame, len, 8, 1, joint);
else
- return sbc_pack_frame_internal(data, frame, len, 8, 2);
+ return sbc_pack_frame_internal(
+ data, frame, len, 8, 2, joint);
}
}
@@ -1124,11 +1072,18 @@ ssize_t sbc_encode(sbc_t *sbc, const void *input, size_t input_len,
samples = sbc_analyze_audio(&priv->enc_state, &priv->frame);
- priv->enc_state.sbc_calc_scalefactors(
- priv->frame.sb_sample_f, priv->frame.scale_factor,
- priv->frame.blocks, priv->frame.channels, priv->frame.subbands);
-
- framelen = sbc_pack_frame(output, &priv->frame, output_len);
+ if (priv->frame.mode == JOINT_STEREO) {
+ int j = priv->enc_state.sbc_calc_scalefactors_j(
+ priv->frame.sb_sample_f, priv->frame.scale_factor,
+ priv->frame.blocks, priv->frame.subbands);
+ framelen = sbc_pack_frame(output, &priv->frame, output_len, j);
+ } else {
+ priv->enc_state.sbc_calc_scalefactors(
+ priv->frame.sb_sample_f, priv->frame.scale_factor,
+ priv->frame.blocks, priv->frame.channels,
+ priv->frame.subbands);
+ framelen = sbc_pack_frame(output, &priv->frame, output_len, 0);
+ }
if (written)
*written = framelen;
diff --git a/src/modules/bluetooth/sbc/sbc_primitives.c b/src/modules/bluetooth/sbc/sbc_primitives.c
index 2105280e..82cd399d 100644
--- a/src/modules/bluetooth/sbc/sbc_primitives.c
+++ b/src/modules/bluetooth/sbc/sbc_primitives.c
@@ -439,6 +439,80 @@ static void sbc_calc_scalefactors(
}
}
+static int sbc_calc_scalefactors_j(
+ int32_t sb_sample_f[16][2][8],
+ uint32_t scale_factor[2][8],
+ int blocks, int subbands)
+{
+ int blk, joint = 0;
+ int32_t tmp0, tmp1;
+ uint32_t x, y;
+
+ /* last subband does not use joint stereo */
+ int sb = subbands - 1;
+ x = 1 << SCALE_OUT_BITS;
+ y = 1 << SCALE_OUT_BITS;
+ for (blk = 0; blk < blocks; blk++) {
+ tmp0 = fabs(sb_sample_f[blk][0][sb]);
+ tmp1 = fabs(sb_sample_f[blk][1][sb]);
+ if (tmp0 != 0)
+ x |= tmp0 - 1;
+ if (tmp1 != 0)
+ y |= tmp1 - 1;
+ }
+ scale_factor[0][sb] = (31 - SCALE_OUT_BITS) - sbc_clz(x);
+ scale_factor[1][sb] = (31 - SCALE_OUT_BITS) - sbc_clz(y);
+
+ /* the rest of subbands can use joint stereo */
+ while (--sb >= 0) {
+ int32_t sb_sample_j[16][2];
+ x = 1 << SCALE_OUT_BITS;
+ y = 1 << SCALE_OUT_BITS;
+ for (blk = 0; blk < blocks; blk++) {
+ tmp0 = sb_sample_f[blk][0][sb];
+ tmp1 = sb_sample_f[blk][1][sb];
+ sb_sample_j[blk][0] = ASR(tmp0, 1) + ASR(tmp1, 1);
+ sb_sample_j[blk][1] = ASR(tmp0, 1) - ASR(tmp1, 1);
+ tmp0 = fabs(tmp0);
+ tmp1 = fabs(tmp1);
+ if (tmp0 != 0)
+ x |= tmp0 - 1;
+ if (tmp1 != 0)
+ y |= tmp1 - 1;
+ }
+ scale_factor[0][sb] = (31 - SCALE_OUT_BITS) -
+ sbc_clz(x);
+ scale_factor[1][sb] = (31 - SCALE_OUT_BITS) -
+ sbc_clz(y);
+ x = 1 << SCALE_OUT_BITS;
+ y = 1 << SCALE_OUT_BITS;
+ for (blk = 0; blk < blocks; blk++) {
+ tmp0 = fabs(sb_sample_j[blk][0]);
+ tmp1 = fabs(sb_sample_j[blk][1]);
+ if (tmp0 != 0)
+ x |= tmp0 - 1;
+ if (tmp1 != 0)
+ y |= tmp1 - 1;
+ }
+ x = (31 - SCALE_OUT_BITS) - sbc_clz(x);
+ y = (31 - SCALE_OUT_BITS) - sbc_clz(y);
+
+ /* decide whether to use joint stereo for this subband */
+ if ((scale_factor[0][sb] + scale_factor[1][sb]) > x + y) {
+ joint |= 1 << (subbands - 1 - sb);
+ scale_factor[0][sb] = x;
+ scale_factor[1][sb] = y;
+ for (blk = 0; blk < blocks; blk++) {
+ sb_sample_f[blk][0][sb] = sb_sample_j[blk][0];
+ sb_sample_f[blk][1][sb] = sb_sample_j[blk][1];
+ }
+ }
+ }
+
+ /* bitmask with the information about subbands using joint stereo */
+ return joint;
+}
+
/*
* Detect CPU features and setup function pointers
*/
@@ -456,6 +530,7 @@ void sbc_init_primitives(struct sbc_encoder_state *state)
/* Default implementation for scale factors calculation */
state->sbc_calc_scalefactors = sbc_calc_scalefactors;
+ state->sbc_calc_scalefactors_j = sbc_calc_scalefactors_j;
state->implementation_info = "Generic C";
/* X86/AMD64 optimizations */
diff --git a/src/modules/bluetooth/sbc/sbc_primitives.h b/src/modules/bluetooth/sbc/sbc_primitives.h
index 3d01c115..b4b9df2f 100644
--- a/src/modules/bluetooth/sbc/sbc_primitives.h
+++ b/src/modules/bluetooth/sbc/sbc_primitives.h
@@ -62,6 +62,10 @@ struct sbc_encoder_state {
void (*sbc_calc_scalefactors)(int32_t sb_sample_f[16][2][8],
uint32_t scale_factor[2][8],
int blocks, int channels, int subbands);
+ /* Scale factors calculation with joint stereo support */
+ int (*sbc_calc_scalefactors_j)(int32_t sb_sample_f[16][2][8],
+ uint32_t scale_factor[2][8],
+ int blocks, int subbands);
const char *implementation_info;
};