opus: move the entropy decoding functions to opus_rc.c

The intention is to have both encoding and decoding functions
in opus_rc.c.

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

1 files changed, 1 insertions, 221 deletions

diff --git a/libavcodec/opus.h b/libavcodec/opus.h
index 3a7ea9f504..2079f423b4 100644
--- a/libavcodec/opus.h
+++ b/libavcodec/opus.h
@@ -32,7 +32,7 @@
 #include "libswresample/swresample.h"
 
 #include "avcodec.h"
-#include "get_bits.h"
+#include "opus_rc.h"
 
 #define MAX_FRAME_SIZE               1275
 #define MAX_FRAMES                   48
@@ -59,7 +59,6 @@
 
 #define ROUND_MULL(a,b,s) (((MUL64(a, b) >> ((s) - 1)) + 1) >> 1)
 #define ROUND_MUL16(a,b)  ((MUL16(a, b) + 16384) >> 15)
-#define opus_ilog(i) (av_log2(i) + !!(i))
 
 #define OPUS_TS_HEADER     0x7FE0        // 0x3ff (11 bits)
 #define OPUS_TS_MASK       0xFFE0        // top 11 bits
@@ -84,21 +83,6 @@ enum OpusBandwidth {
     OPUS_BANDWIDTH_FULLBAND
 };
 
-typedef struct RawBitsContext {
-    const uint8_t *position;
-    unsigned int bytes;
-    unsigned int cachelen;
-    unsigned int cacheval;
-} RawBitsContext;
-
-typedef struct OpusRangeCoder {
-    GetBitContext gb;
-    RawBitsContext rb;
-    unsigned int range;
-    unsigned int value;
-    unsigned int total_read_bits;
-} OpusRangeCoder;
-
 typedef struct SilkContext SilkContext;
 
 typedef struct CeltContext CeltContext;
@@ -193,210 +177,6 @@ typedef struct OpusContext {
     ChannelMap *channel_maps;
 } OpusContext;
 
-static av_always_inline void opus_rc_normalize(OpusRangeCoder *rc)
-{
-    while (rc->range <= 1<<23) {
-        rc->value = ((rc->value << 8) | (get_bits(&rc->gb, 8) ^ 0xFF)) & ((1u << 31) - 1);
-        rc->range          <<= 8;
-        rc->total_read_bits += 8;
-    }
-}
-
-static av_always_inline void opus_rc_update(OpusRangeCoder *rc, unsigned int scale,
-                                          unsigned int low, unsigned int high,
-                                          unsigned int total)
-{
-    rc->value -= scale * (total - high);
-    rc->range  = low ? scale * (high - low)
-                      : rc->range - scale * (total - high);
-    opus_rc_normalize(rc);
-}
-
-static av_always_inline unsigned int opus_rc_getsymbol(OpusRangeCoder *rc, const uint16_t *cdf)
-{
-    unsigned int k, scale, total, symbol, low, high;
-
-    total = *cdf++;
-
-    scale   = rc->range / total;
-    symbol = rc->value / scale + 1;
-    symbol = total - FFMIN(symbol, total);
-
-    for (k = 0; cdf[k] <= symbol; k++);
-    high = cdf[k];
-    low  = k ? cdf[k-1] : 0;
-
-    opus_rc_update(rc, scale, low, high, total);
-
-    return k;
-}
-
-static av_always_inline unsigned int opus_rc_p2model(OpusRangeCoder *rc, unsigned int bits)
-{
-    unsigned int k, scale;
-    scale = rc->range >> bits; // in this case, scale = symbol
-
-    if (rc->value >= scale) {
-        rc->value -= scale;
-        rc->range -= scale;
-        k = 0;
-    } else {
-        rc->range = scale;
-        k = 1;
-    }
-    opus_rc_normalize(rc);
-    return k;
-}
-
-/**
- * CELT: estimate bits of entropy that have thus far been consumed for the
- *       current CELT frame, to integer and fractional (1/8th bit) precision
- */
-static av_always_inline unsigned int opus_rc_tell(const OpusRangeCoder *rc)
-{
-    return rc->total_read_bits - av_log2(rc->range) - 1;
-}
-
-static av_always_inline unsigned int opus_rc_tell_frac(const OpusRangeCoder *rc)
-{
-    unsigned int i, total_bits, rcbuffer, range;
-
-    total_bits = rc->total_read_bits << 3;
-    rcbuffer   = av_log2(rc->range) + 1;
-    range      = rc->range >> (rcbuffer-16);
-
-    for (i = 0; i < 3; i++) {
-        int bit;
-        range = range * range >> 15;
-        bit = range >> 16;
-        rcbuffer = rcbuffer << 1 | bit;
-        range >>= bit;
-    }
-
-    return total_bits - rcbuffer;
-}
-
-/**
- * CELT: read 1-25 raw bits at the end of the frame, backwards byte-wise
- */
-static av_always_inline unsigned int opus_getrawbits(OpusRangeCoder *rc, unsigned int count)
-{
-    unsigned int value = 0;
-
-    while (rc->rb.bytes && rc->rb.cachelen < count) {
-        rc->rb.cacheval |= *--rc->rb.position << rc->rb.cachelen;
-        rc->rb.cachelen += 8;
-        rc->rb.bytes--;
-    }
-
-    value = av_mod_uintp2(rc->rb.cacheval, count);
-    rc->rb.cacheval    >>= count;
-    rc->rb.cachelen     -= count;
-    rc->total_read_bits += count;
-
-    return value;
-}
-
-/**
- * CELT: read a uniform distribution
- */
-static av_always_inline unsigned int opus_rc_unimodel(OpusRangeCoder *rc, unsigned int size)
-{
-    unsigned int bits, k, scale, total;
-
-    bits  = opus_ilog(size - 1);
-    total = (bits > 8) ? ((size - 1) >> (bits - 8)) + 1 : size;
-
-    scale  = rc->range / total;
-    k      = rc->value / scale + 1;
-    k      = total - FFMIN(k, total);
-    opus_rc_update(rc, scale, k, k + 1, total);
-
-    if (bits > 8) {
-        k = k << (bits - 8) | opus_getrawbits(rc, bits - 8);
-        return FFMIN(k, size - 1);
-    } else
-        return k;
-}
-
-static av_always_inline int opus_rc_laplace(OpusRangeCoder *rc, unsigned int symbol, int decay)
-{
-    /* extends the range coder to model a Laplace distribution */
-    int value = 0;
-    unsigned int scale, low = 0, center;
-
-    scale  = rc->range >> 15;
-    center = rc->value / scale + 1;
-    center = (1 << 15) - FFMIN(center, 1 << 15);
-
-    if (center >= symbol) {
-        value++;
-        low = symbol;
-        symbol = 1 + ((32768 - 32 - symbol) * (16384-decay) >> 15);
-
-        while (symbol > 1 && center >= low + 2 * symbol) {
-            value++;
-            symbol *= 2;
-            low    += symbol;
-            symbol  = (((symbol - 2) * decay) >> 15) + 1;
-        }
-
-        if (symbol <= 1) {
-            int distance = (center - low) >> 1;
-            value += distance;
-            low   += 2 * distance;
-        }
-
-        if (center < low + symbol)
-            value *= -1;
-        else
-            low += symbol;
-    }
-
-    opus_rc_update(rc, scale, low, FFMIN(low + symbol, 32768), 32768);
-
-    return value;
-}
-
-static av_always_inline unsigned int opus_rc_stepmodel(OpusRangeCoder *rc, int k0)
-{
-    /* Use a probability of 3 up to itheta=8192 and then use 1 after */
-    unsigned int k, scale, symbol, total = (k0+1)*3 + k0;
-    scale  = rc->range / total;
-    symbol = rc->value / scale + 1;
-    symbol = total - FFMIN(symbol, total);
-
-    k = (symbol < (k0+1)*3) ? symbol/3 : symbol - (k0+1)*2;
-
-    opus_rc_update(rc, scale, (k <= k0) ? 3*(k+0) : (k-1-k0) + 3*(k0+1),
-                   (k <= k0) ? 3*(k+1) : (k-0-k0) + 3*(k0+1), total);
-    return k;
-}
-
-static av_always_inline unsigned int opus_rc_trimodel(OpusRangeCoder *rc, int qn)
-{
-    unsigned int k, scale, symbol, total, low, center;
-
-    total = ((qn>>1) + 1) * ((qn>>1) + 1);
-    scale   = rc->range / total;
-    center = rc->value / scale + 1;
-    center = total - FFMIN(center, total);
-
-    if (center < total >> 1) {
-        k      = (ff_sqrt(8 * center + 1) - 1) >> 1;
-        low    = k * (k + 1) >> 1;
-        symbol = k + 1;
-    } else {
-        k      = (2*(qn + 1) - ff_sqrt(8*(total - center - 1) + 1)) >> 1;
-        low    = total - ((qn + 1 - k) * (qn + 2 - k) >> 1);
-        symbol = qn + 1 - k;
-    }
-
-    opus_rc_update(rc, scale, low, low + symbol, total);
-
-    return k;
-}
-
 int ff_opus_parse_packet(OpusPacket *pkt, const uint8_t *buf, int buf_size,
                          int self_delimited);