#include <stdint.h>
-#include "ac3enc.h"
-
/* prototypes for static functions in ac3enc_fixed.c and ac3enc_float.c */
static void clip_coefficients(DSPContext *dsp, CoefType *coef, unsigned int len);
+static CoefType calc_cpl_coord(CoefSumType energy_ch, CoefSumType energy_cpl);
+
int AC3_NAME(allocate_sample_buffers)(AC3EncodeContext *s)
{
}
-/**
+/*
* Deinterleave input samples.
* Channels are reordered from Libav's default order to AC-3 order.
*/
}
-/**
+/*
* Apply the MDCT to input samples to generate frequency coefficients.
* This applies the KBD window and normalizes the input to reduce precision
* loss due to fixed-point calculations.
}
-/**
- * Calculate a single coupling coordinate.
- */
-static inline float calc_cpl_coord(float energy_ch, float energy_cpl)
-{
- float coord = 0.125;
- if (energy_cpl > 0)
- coord *= sqrtf(energy_ch / energy_cpl);
- return coord;
-}
-
-
-/**
+/*
* Calculate coupling channel and coupling coordinates.
- * TODO: Currently this is only used for the floating-point encoder. I was
- * able to make it work for the fixed-point encoder, but quality was
- * generally lower in most cases than not using coupling. If a more
- * adaptive coupling strategy were to be implemented it might be useful
- * at that time to use coupling for the fixed-point encoder as well.
*/
static void apply_channel_coupling(AC3EncodeContext *s)
{
+ LOCAL_ALIGNED_16(CoefType, cpl_coords, [AC3_MAX_BLOCKS], [AC3_MAX_CHANNELS][16]);
#if CONFIG_AC3ENC_FLOAT
- LOCAL_ALIGNED_16(float, cpl_coords, [AC3_MAX_BLOCKS], [AC3_MAX_CHANNELS][16]);
LOCAL_ALIGNED_16(int32_t, fixed_cpl_coords, [AC3_MAX_BLOCKS], [AC3_MAX_CHANNELS][16]);
+#else
+ int32_t (*fixed_cpl_coords)[AC3_MAX_CHANNELS][16] = cpl_coords;
+#endif
int blk, ch, bnd, i, j;
CoefSumType energy[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][16] = {{{0}}};
int cpl_start, num_cpl_coefs;
memset(cpl_coords, 0, AC3_MAX_BLOCKS * sizeof(*cpl_coords));
- memset(fixed_cpl_coords, 0, AC3_MAX_BLOCKS * sizeof(*fixed_cpl_coords));
+#if CONFIG_AC3ENC_FLOAT
+ memset(fixed_cpl_coords, 0, AC3_MAX_BLOCKS * sizeof(*cpl_coords));
+#endif
/* align start to 16-byte boundary. align length to multiple of 32.
note: coupling start bin % 4 will always be 1 */
/* coefficients must be clipped in order to be encoded */
clip_coefficients(&s->dsp, cpl_coef, num_cpl_coefs);
-
- /* scale coupling coefficients from float to 24-bit fixed-point */
- s->ac3dsp.float_to_fixed24(&block->fixed_coef[CPL_CH][cpl_start],
- cpl_coef, num_cpl_coefs);
}
/* calculate energy in each band in coupling channel and each fbw channel */
bnd++;
}
+ /* calculate coupling coordinates for all blocks for all channels */
+ for (blk = 0; blk < s->num_blocks; blk++) {
+ AC3Block *block = &s->blocks[blk];
+ if (!block->cpl_in_use)
+ continue;
+ for (ch = 1; ch <= s->fbw_channels; ch++) {
+ if (!block->channel_in_cpl[ch])
+ continue;
+ for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
+ cpl_coords[blk][ch][bnd] = calc_cpl_coord(energy[blk][ch][bnd],
+ energy[blk][CPL_CH][bnd]);
+ }
+ }
+ }
+
/* determine which blocks to send new coupling coordinates for */
for (blk = 0; blk < s->num_blocks; blk++) {
AC3Block *block = &s->blocks[blk];
AC3Block *block0 = blk ? &s->blocks[blk-1] : NULL;
- CoefSumType coord_diff[AC3_MAX_CHANNELS] = {0,};
memset(block->new_cpl_coords, 0, sizeof(block->new_cpl_coords));
if (block->cpl_in_use) {
- /* calculate coupling coordinates for all blocks and calculate the
- average difference between coordinates in successive blocks */
- for (ch = 1; ch <= s->fbw_channels; ch++) {
- if (!block->channel_in_cpl[ch])
- continue;
-
- for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
- cpl_coords[blk][ch][bnd] = calc_cpl_coord(energy[blk][ch][bnd],
- energy[blk][CPL_CH][bnd]);
- if (blk > 0 && block0->cpl_in_use &&
- block0->channel_in_cpl[ch]) {
- coord_diff[ch] += fabs(cpl_coords[blk-1][ch][bnd] -
- cpl_coords[blk ][ch][bnd]);
- }
- }
- coord_diff[ch] /= s->num_cpl_bands;
- }
-
/* send new coordinates if this is the first block, if previous
* block did not use coupling but this block does, the channels
* using coupling has changed from the previous block, or the
block->new_cpl_coords[ch] = 1;
} else {
for (ch = 1; ch <= s->fbw_channels; ch++) {
- if ((block->channel_in_cpl[ch] && !block0->channel_in_cpl[ch]) ||
- (block->channel_in_cpl[ch] && coord_diff[ch] > 0.03)) {
+ if (!block->channel_in_cpl[ch])
+ continue;
+ if (!block0->channel_in_cpl[ch]) {
block->new_cpl_coords[ch] = 1;
+ } else {
+ CoefSumType coord_diff = 0;
+ for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
+ coord_diff += FFABS(cpl_coords[blk-1][ch][bnd] -
+ cpl_coords[blk ][ch][bnd]);
+ }
+ coord_diff /= s->num_cpl_bands;
+ if (coord_diff > NEW_CPL_COORD_THRESHOLD)
+ block->new_cpl_coords[ch] = 1;
}
}
}
if (!block->cpl_in_use)
continue;
- clip_coefficients(&s->dsp, cpl_coords[blk][1], s->fbw_channels * 16);
+#if CONFIG_AC3ENC_FLOAT
s->ac3dsp.float_to_fixed24(fixed_cpl_coords[blk][1],
cpl_coords[blk][1],
s->fbw_channels * 16);
+#endif
s->ac3dsp.extract_exponents(block->cpl_coord_exp[1],
fixed_cpl_coords[blk][1],
s->fbw_channels * 16);
if (CONFIG_EAC3_ENCODER && s->eac3)
ff_eac3_set_cpl_states(s);
-#endif /* CONFIG_AC3ENC_FLOAT */
}
-/**
+/*
* Determine rematrixing flags for each block and band.
*/
static void compute_rematrixing_strategy(AC3EncodeContext *s)
block = &s->blocks[blk];
block->new_rematrixing_strategy = !blk;
- if (!s->rematrixing_enabled) {
- block0 = block;
- continue;
- }
-
block->num_rematrixing_bands = 4;
if (block->cpl_in_use) {
block->num_rematrixing_bands -= (s->start_freq[CPL_CH] <= 61);
}
nb_coefs = FFMIN(block->end_freq[1], block->end_freq[2]);
+ if (!s->rematrixing_enabled) {
+ block0 = block;
+ continue;
+ }
+
for (bnd = 0; bnd < block->num_rematrixing_bands; bnd++) {
/* calculate calculate sum of squared coeffs for one band in one block */
int start = ff_ac3_rematrix_band_tab[bnd];
}
-/**
- * Encode a single AC-3 frame.
- */
int AC3_NAME(encode_frame)(AVCodecContext *avctx, unsigned char *frame,
int buf_size, void *data)
{
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