opus: merge encoder and decoder bitallocation functions into one

There's no difference apart from which entropy coding functions get called.

Signed-off-by: Rostislav Pehlivanov <atomnuker@gmail.com>

1 files changed, 348 insertions, 0 deletions

diff --git a/libavcodec/opus.c b/libavcodec/opus.c
index 46b749cae6..9cbf4aed92 100644
--- a/libavcodec/opus.c
+++ b/libavcodec/opus.c
@@ -546,3 +546,351 @@ void ff_celt_quant_bands(CeltFrame *f, OpusRangeCoder *rc)
         update_lowband = (b > band_size << 3);
     }
 }
+
+#define NORMC(bits) ((bits) << (f->channels - 1) << f->size >> 2)
+
+void ff_celt_bitalloc(CeltFrame *f, OpusRangeCoder *rc, int encode)
+{
+    int i, j, low, high, total, done, bandbits, remaining, tbits_8ths;
+    int skip_startband      = f->start_band;
+    int skip_bit            = 0;
+    int intensitystereo_bit = 0;
+    int dualstereo_bit      = 0;
+    int dynalloc            = 6;
+    int extrabits           = 0;
+
+    int boost[CELT_MAX_BANDS] = { 0 };
+    int trim_offset[CELT_MAX_BANDS];
+    int threshold[CELT_MAX_BANDS];
+    int bits1[CELT_MAX_BANDS];
+    int bits2[CELT_MAX_BANDS];
+
+    /* Spread */
+    if (opus_rc_tell(rc) + 4 <= f->framebits)
+        if (encode)
+            ff_opus_rc_enc_cdf(rc, f->spread, ff_celt_model_spread);
+        else
+            f->spread = ff_opus_rc_dec_cdf(rc, ff_celt_model_spread);
+    else
+        f->spread = CELT_SPREAD_NORMAL;
+
+    /* Initialize static allocation caps */
+    for (i = 0; i < CELT_MAX_BANDS; i++)
+        f->caps[i] = NORMC((ff_celt_static_caps[f->size][f->channels - 1][i] + 64) * ff_celt_freq_range[i]);
+
+    /* Band boosts */
+    tbits_8ths = f->framebits << 3;
+    for (i = f->start_band; i < f->end_band; i++) {
+        int quanta = ff_celt_freq_range[i] << (f->channels - 1) << f->size;
+        int b_dynalloc = dynalloc;
+        int boost_amount = f->alloc_boost[i];
+        quanta = FFMIN(quanta << 3, FFMAX(6 << 3, quanta));
+
+        while (opus_rc_tell_frac(rc) + (b_dynalloc << 3) < tbits_8ths && boost[i] < f->caps[i]) {
+            int is_boost;
+            if (encode) {
+                is_boost = boost_amount--;
+                ff_opus_rc_enc_log(rc, is_boost, b_dynalloc);
+            } else {
+                is_boost = ff_opus_rc_dec_log(rc, b_dynalloc);
+            }
+
+            if (!is_boost)
+                break;
+
+            boost[i]   += quanta;
+            tbits_8ths -= quanta;
+
+            b_dynalloc = 1;
+        }
+
+        if (boost[i])
+            dynalloc = FFMAX(dynalloc - 1, 2);
+    }
+
+    /* Allocation trim */
+    if (opus_rc_tell_frac(rc) + (6 << 3) <= tbits_8ths)
+        if (encode)
+            ff_opus_rc_enc_cdf(rc, f->alloc_trim, ff_celt_model_alloc_trim);
+        else
+            f->alloc_trim = ff_opus_rc_dec_cdf(rc, ff_celt_model_alloc_trim);
+
+    /* Anti-collapse bit reservation */
+    tbits_8ths = (f->framebits << 3) - opus_rc_tell_frac(rc) - 1;
+    f->anticollapse_needed = 0;
+    if (f->transient && f->size >= 2 && tbits_8ths >= ((f->size + 2) << 3))
+        f->anticollapse_needed = 1 << 3;
+    tbits_8ths -= f->anticollapse_needed;
+
+    /* Band skip bit reservation */
+    if (tbits_8ths >= 1 << 3)
+        skip_bit = 1 << 3;
+    tbits_8ths -= skip_bit;
+
+    /* Intensity/dual stereo bit reservation */
+    if (f->channels == 2) {
+        intensitystereo_bit = ff_celt_log2_frac[f->end_band - f->start_band];
+        if (intensitystereo_bit <= tbits_8ths) {
+            tbits_8ths -= intensitystereo_bit;
+            if (tbits_8ths >= 1 << 3) {
+                dualstereo_bit = 1 << 3;
+                tbits_8ths -= 1 << 3;
+            }
+        } else {
+            intensitystereo_bit = 0;
+        }
+    }
+
+    /* Trim offsets */
+    for (i = f->start_band; i < f->end_band; i++) {
+        int trim     = f->alloc_trim - 5 - f->size;
+        int band     = ff_celt_freq_range[i] * (f->end_band - i - 1);
+        int duration = f->size + 3;
+        int scale    = duration + f->channels - 1;
+
+        /* PVQ minimum allocation threshold, below this value the band is
+         * skipped */
+        threshold[i] = FFMAX(3 * ff_celt_freq_range[i] << duration >> 4,
+                             f->channels << 3);
+
+        trim_offset[i] = trim * (band << scale) >> 6;
+
+        if (ff_celt_freq_range[i] << f->size == 1)
+            trim_offset[i] -= f->channels << 3;
+    }
+
+    /* Bisection */
+    low  = 1;
+    high = CELT_VECTORS - 1;
+    while (low <= high) {
+        int center = (low + high) >> 1;
+        done = total = 0;
+
+        for (i = f->end_band - 1; i >= f->start_band; i--) {
+            bandbits = NORMC(ff_celt_freq_range[i] * ff_celt_static_alloc[center][i]);
+
+            if (bandbits)
+                bandbits = FFMAX(bandbits + trim_offset[i], 0);
+            bandbits += boost[i];
+
+            if (bandbits >= threshold[i] || done) {
+                done = 1;
+                total += FFMIN(bandbits, f->caps[i]);
+            } else if (bandbits >= f->channels << 3) {
+                total += f->channels << 3;
+            }
+        }
+
+        if (total > tbits_8ths)
+            high = center - 1;
+        else
+            low = center + 1;
+    }
+    high = low--;
+
+    /* Bisection */
+    for (i = f->start_band; i < f->end_band; i++) {
+        bits1[i] = NORMC(ff_celt_freq_range[i] * ff_celt_static_alloc[low][i]);
+        bits2[i] = high >= CELT_VECTORS ? f->caps[i] :
+                   NORMC(ff_celt_freq_range[i] * ff_celt_static_alloc[high][i]);
+
+        if (bits1[i])
+            bits1[i] = FFMAX(bits1[i] + trim_offset[i], 0);
+        if (bits2[i])
+            bits2[i] = FFMAX(bits2[i] + trim_offset[i], 0);
+
+        if (low)
+            bits1[i] += boost[i];
+        bits2[i] += boost[i];
+
+        if (boost[i])
+            skip_startband = i;
+        bits2[i] = FFMAX(bits2[i] - bits1[i], 0);
+    }
+
+    /* Bisection */
+    low  = 0;
+    high = 1 << CELT_ALLOC_STEPS;
+    for (i = 0; i < CELT_ALLOC_STEPS; i++) {
+        int center = (low + high) >> 1;
+        done = total = 0;
+
+        for (j = f->end_band - 1; j >= f->start_band; j--) {
+            bandbits = bits1[j] + (center * bits2[j] >> CELT_ALLOC_STEPS);
+
+            if (bandbits >= threshold[j] || done) {
+                done = 1;
+                total += FFMIN(bandbits, f->caps[j]);
+            } else if (bandbits >= f->channels << 3)
+                total += f->channels << 3;
+        }
+        if (total > tbits_8ths)
+            high = center;
+        else
+            low = center;
+    }
+
+    /* Bisection */
+    done = total = 0;
+    for (i = f->end_band - 1; i >= f->start_band; i--) {
+        bandbits = bits1[i] + (low * bits2[i] >> CELT_ALLOC_STEPS);
+
+        if (bandbits >= threshold[i] || done)
+            done = 1;
+        else
+            bandbits = (bandbits >= f->channels << 3) ?
+            f->channels << 3 : 0;
+
+        bandbits     = FFMIN(bandbits, f->caps[i]);
+        f->pulses[i] = bandbits;
+        total      += bandbits;
+    }
+
+    /* Band skipping */
+    for (f->coded_bands = f->end_band; ; f->coded_bands--) {
+        int allocation;
+        j = f->coded_bands - 1;
+
+        if (j == skip_startband) {
+            /* all remaining bands are not skipped */
+            tbits_8ths += skip_bit;
+            break;
+        }
+
+        /* determine the number of bits available for coding "do not skip" markers */
+        remaining   = tbits_8ths - total;
+        bandbits    = remaining / (ff_celt_freq_bands[j+1] - ff_celt_freq_bands[f->start_band]);
+        remaining  -= bandbits  * (ff_celt_freq_bands[j+1] - ff_celt_freq_bands[f->start_band]);
+        allocation  = f->pulses[j] + bandbits * ff_celt_freq_range[j];
+        allocation += FFMAX(remaining - (ff_celt_freq_bands[j] - ff_celt_freq_bands[f->start_band]), 0);
+
+        /* a "do not skip" marker is only coded if the allocation is
+         * above the chosen threshold */
+        if (allocation >= FFMAX(threshold[j], (f->channels + 1) << 3)) {
+            int do_not_skip;
+            if (encode) {
+                do_not_skip = f->coded_bands <= f->skip_band_floor;
+                ff_opus_rc_enc_log(rc, do_not_skip, 1);
+            } else {
+                do_not_skip = ff_opus_rc_dec_log(rc, 1);
+            }
+
+            if (do_not_skip)
+                break;
+
+            total      += 1 << 3;
+            allocation -= 1 << 3;
+        }
+
+        /* the band is skipped, so reclaim its bits */
+        total -= f->pulses[j];
+        if (intensitystereo_bit) {
+            total -= intensitystereo_bit;
+            intensitystereo_bit = ff_celt_log2_frac[j - f->start_band];
+            total += intensitystereo_bit;
+        }
+
+        total += f->pulses[j] = (allocation >= f->channels << 3) ? f->channels << 3 : 0;
+    }
+
+    /* IS start band */
+    if (encode) {
+        if (intensitystereo_bit) {
+            f->intensity_stereo = FFMIN(f->intensity_stereo, f->coded_bands);
+            ff_opus_rc_enc_uint(rc, f->intensity_stereo, f->coded_bands + 1 - f->start_band);
+        }
+    } else {
+        f->intensity_stereo = f->dual_stereo = 0;
+        if (intensitystereo_bit)
+            f->intensity_stereo = f->start_band + ff_opus_rc_dec_uint(rc, f->coded_bands + 1 - f->start_band);
+    }
+
+    /* DS flag */
+    if (f->intensity_stereo <= f->start_band)
+        tbits_8ths += dualstereo_bit; /* no intensity stereo means no dual stereo */
+    else if (dualstereo_bit)
+        if (encode)
+            ff_opus_rc_enc_log(rc, f->dual_stereo, 1);
+        else
+            f->dual_stereo = ff_opus_rc_dec_log(rc, 1);
+
+    /* Supply the remaining bits in this frame to lower bands */
+    remaining = tbits_8ths - total;
+    bandbits  = remaining / (ff_celt_freq_bands[f->coded_bands] - ff_celt_freq_bands[f->start_band]);
+    remaining -= bandbits * (ff_celt_freq_bands[f->coded_bands] - ff_celt_freq_bands[f->start_band]);
+    for (i = f->start_band; i < f->coded_bands; i++) {
+        const int bits = FFMIN(remaining, ff_celt_freq_range[i]);
+        f->pulses[i] += bits + bandbits * ff_celt_freq_range[i];
+        remaining    -= bits;
+    }
+
+    /* Finally determine the allocation */
+    for (i = f->start_band; i < f->coded_bands; i++) {
+        int N = ff_celt_freq_range[i] << f->size;
+        int prev_extra = extrabits;
+        f->pulses[i] += extrabits;
+
+        if (N > 1) {
+            int dof;        /* degrees of freedom */
+            int temp;       /* dof * channels * log(dof) */
+            int fine_bits;
+            int max_bits;
+            int offset;     /* fine energy quantization offset, i.e.
+                             * extra bits assigned over the standard
+                             * totalbits/dof */
+
+            extrabits = FFMAX(f->pulses[i] - f->caps[i], 0);
+            f->pulses[i] -= extrabits;
+
+            /* intensity stereo makes use of an extra degree of freedom */
+            dof = N * f->channels + (f->channels == 2 && N > 2 && !f->dual_stereo && i < f->intensity_stereo);
+            temp = dof * (ff_celt_log_freq_range[i] + (f->size << 3));
+            offset = (temp >> 1) - dof * CELT_FINE_OFFSET;
+            if (N == 2) /* dof=2 is the only case that doesn't fit the model */
+                offset += dof << 1;
+
+            /* grant an additional bias for the first and second pulses */
+            if (f->pulses[i] + offset < 2 * (dof << 3))
+                offset += temp >> 2;
+            else if (f->pulses[i] + offset < 3 * (dof << 3))
+                offset += temp >> 3;
+
+            fine_bits = (f->pulses[i] + offset + (dof << 2)) / (dof << 3);
+            max_bits  = FFMIN((f->pulses[i] >> 3) >> (f->channels - 1), CELT_MAX_FINE_BITS);
+            max_bits  = FFMAX(max_bits, 0);
+            f->fine_bits[i] = av_clip(fine_bits, 0, max_bits);
+
+            /* If fine_bits was rounded down or capped,
+             * give priority for the final fine energy pass */
+            f->fine_priority[i] = (f->fine_bits[i] * (dof << 3) >= f->pulses[i] + offset);
+
+            /* the remaining bits are assigned to PVQ */
+            f->pulses[i] -= f->fine_bits[i] << (f->channels - 1) << 3;
+        } else {
+            /* all bits go to fine energy except for the sign bit */
+            extrabits = FFMAX(f->pulses[i] - (f->channels << 3), 0);
+            f->pulses[i] -= extrabits;
+            f->fine_bits[i] = 0;
+            f->fine_priority[i] = 1;
+        }
+
+        /* hand back a limited number of extra fine energy bits to this band */
+        if (extrabits > 0) {
+            int fineextra = FFMIN(extrabits >> (f->channels + 2),
+                                  CELT_MAX_FINE_BITS - f->fine_bits[i]);
+            f->fine_bits[i] += fineextra;
+
+            fineextra <<= f->channels + 2;
+            f->fine_priority[i] = (fineextra >= extrabits - prev_extra);
+            extrabits -= fineextra;
+        }
+    }
+    f->remaining = extrabits;
+
+    /* skipped bands dedicate all of their bits for fine energy */
+    for (; i < f->end_band; i++) {
+        f->fine_bits[i]     = f->pulses[i] >> (f->channels - 1) >> 3;
+        f->pulses[i]        = 0;
+        f->fine_priority[i] = f->fine_bits[i] < 1;
+    }
+}