/*
* Real Audio 1.0 (14.4K)
- * Copyright (c) 2003 the ffmpeg project
+ *
+ * Copyright (c) 2008 Vitor Sessak
+ * Copyright (c) 2003 Nick Kurshev
+ * Based on public domain decoder at http://www.honeypot.net/audio
*
* This file is part of FFmpeg.
*
#include "avcodec.h"
#include "bitstream.h"
#include "ra144.h"
+#include "celp_filters.h"
-#define NBLOCKS 4 /* number of segments within a block */
-#define BLOCKSIZE 40 /* (quarter) block size in 16-bit words (80 bytes) */
-#define HALFBLOCK 20 /* BLOCKSIZE/2 */
-#define BUFFERSIZE 146 /* for do_output */
+#define NBLOCKS 4 ///< number of subblocks within a block
+#define BLOCKSIZE 40 ///< subblock size in 16-bit words
+#define BUFFERSIZE 146 ///< the size of the adaptive codebook
-/* internal globals */
typedef struct {
unsigned int old_energy; ///< previous frame energy
- /* the swapped buffers */
- unsigned int lpc_tables[4][10];
- unsigned int *lpc_refl; ///< LPC reflection coefficients
- unsigned int *lpc_coef; ///< LPC coefficients
- unsigned int *lpc_refl_old; ///< previous frame LPC reflection coefs
- unsigned int *lpc_coef_old; ///< previous frame LPC coefficients
+ unsigned int lpc_tables[2][10];
+
+ /** LPC coefficients: lpc_coef[0] is the coefficients of the current frame
+ * and lpc_coef[1] of the previous one. */
+ unsigned int *lpc_coef[2];
+
+ unsigned int lpc_refl_rms[2];
- unsigned int buffer[5];
- uint16_t adapt_cb[148]; ///< adaptive codebook
+ /** The current subblock padded by the last 10 values of the previous one. */
+ int16_t curr_sblock[50];
+
+ /** Adaptive codebook, its size is two units bigger to avoid a
+ * buffer overflow. */
+ uint16_t adapt_cb[146+2];
} RA144Context;
-static int ra144_decode_init(AVCodecContext * avctx)
+static av_cold int ra144_decode_init(AVCodecContext * avctx)
{
RA144Context *ractx = avctx->priv_data;
- ractx->lpc_refl = ractx->lpc_tables[0];
- ractx->lpc_coef = ractx->lpc_tables[1];
- ractx->lpc_refl_old = ractx->lpc_tables[2];
- ractx->lpc_coef_old = ractx->lpc_tables[3];
+ ractx->lpc_coef[0] = ractx->lpc_tables[0];
+ ractx->lpc_coef[1] = ractx->lpc_tables[1];
+ avctx->sample_fmt = SAMPLE_FMT_S16;
return 0;
}
*/
static int t_sqrt(unsigned int x)
{
- int s = 0;
+ int s = 2;
while (x > 0xfff) {
s++;
- x = x >> 2;
+ x >>= 2;
}
- return (ff_sqrt(x << 20) << s) << 2;
+ return ff_sqrt(x << 20) << s;
}
-/* do 'voice' */
-static void do_voice(const int *a1, int *a2)
+/**
+ * Evaluate the LPC filter coefficients from the reflection coefficients.
+ * Does the inverse of the eval_refl() function.
+ */
+static void eval_coefs(int *coefs, const int *refl)
{
int buffer[10];
int *b1 = buffer;
- int *b2 = a2;
- int x, y;
+ int *b2 = coefs;
+ int i, j;
- for (x=0; x < 10; x++) {
- b1[x] = a1[x] << 4;
+ for (i=0; i < 10; i++) {
+ b1[i] = refl[i] << 4;
- for (y=0; y < x; y++)
- b1[y] = ((a1[x] * b2[x-y-1]) >> 12) + b2[y];
+ for (j=0; j < i; j++)
+ b1[j] = ((refl[i] * b2[i-j-1]) >> 12) + b2[j];
FFSWAP(int *, b1, b2);
}
- for (x=0; x < 10; x++)
- a2[x] >>= 4;
+ for (i=0; i < 10; i++)
+ coefs[i] >>= 4;
}
-/* rotate block */
-static void rotate_block(const int16_t *source, int16_t *target, int offset)
+/**
+ * Copy the last offset values of *source to *target. If those values are not
+ * enough to fill the target buffer, fill it with another copy of those values.
+ */
+static void copy_and_dup(int16_t *target, const int16_t *source, int offset)
{
- int i=0, k=0;
source += BUFFERSIZE - offset;
- while (i<BLOCKSIZE) {
- target[i++] = source[k++];
-
- if (k == offset)
- k = 0;
- }
+ memcpy(target, source, FFMIN(BLOCKSIZE, offset)*sizeof(*target));
+ if (offset < BLOCKSIZE)
+ memcpy(target + offset, source, (BLOCKSIZE - offset)*sizeof(*target));
}
-/* inverse root mean square */
-static int irms(const int16_t *data, int factor)
+/** inverse root mean square */
+static int irms(const int16_t *data)
{
unsigned int i, sum = 0;
if (sum == 0)
return 0; /* OOPS - division by zero */
- return (0x20000000 / (t_sqrt(sum) >> 8)) * factor;
+ return 0x20000000 / (t_sqrt(sum) >> 8);
}
-/* multiply/add wavetable */
-static void add_wav(int n, int skip_first, int *m, const int16_t *s1,
- const int8_t *s2, const int8_t *s3, int16_t *dest)
+static void add_wav(int16_t *dest, int n, int skip_first, int *m,
+ const int16_t *s1, const int8_t *s2, const int8_t *s3)
{
int i;
int v[3];
v[0] = 0;
for (i=!skip_first; i<3; i++)
- v[i] = (wavtable1[n][i] * m[i]) >> (wavtable2[n][i] + 1);
+ v[i] = (gain_val_tab[n][i] * m[i]) >> gain_exp_tab[n];
for (i=0; i < BLOCKSIZE; i++)
- dest[i] = ((*(s1++))*v[0] + (*(s2++))*v[1] + (*(s3++))*v[2]) >> 12;
+ dest[i] = (s1[i]*v[0] + s2[i]*v[1] + s3[i]*v[2]) >> 12;
}
-
-static void final(const int16_t *i1, const int16_t *i2,
- void *out, int *statbuf, int len)
+static unsigned int rescale_rms(unsigned int rms, unsigned int energy)
{
- int x, i;
- uint16_t work[50];
- int16_t *ptr = work;
-
- memcpy(work, statbuf,20);
- memcpy(work + 10, i2, len * 2);
-
- for (i=0; i<len; i++) {
- int sum = 0;
- int new_val;
-
- for(x=0; x<10; x++)
- sum += i1[9-x] * ptr[x];
-
- sum >>= 12;
-
- new_val = ptr[10] - sum;
-
- if (new_val < -32768 || new_val > 32767) {
- memset(out, 0, len * 2);
- memset(statbuf, 0, 20);
- return;
- }
-
- ptr[10] = new_val;
- ptr++;
- }
-
- memcpy(out, work+10, len * 2);
- memcpy(statbuf, work + 40, 20);
+ return (rms * energy) >> 10;
}
-static unsigned int rms(const int *data, int f)
+static unsigned int rms(const int *data)
{
- int x;
+ int i;
unsigned int res = 0x10000;
- int b = 0;
+ int b = 10;
- for (x=0; x<10; x++) {
- res = (((0x1000000 - (*data) * (*data)) >> 12) * res) >> 12;
+ for (i=0; i < 10; i++) {
+ res = (((0x1000000 - data[i]*data[i]) >> 12) * res) >> 12;
if (res == 0)
return 0;
- if (res > 0x10000)
- return 0; /* We're screwed, might as well go out with a bang. :P */
-
while (res <= 0x3fff) {
b++;
res <<= 2;
}
- data++;
}
- if (res > 0)
- res = t_sqrt(res);
-
- res >>= (b + 10);
- res = (res * f) >> 10;
- return res;
+ return t_sqrt(res) >> b;
}
-/* do quarter-block output */
-static void do_output_subblock(RA144Context *ractx,
- const uint16_t *gsp, unsigned int gval,
- int16_t *output_buffer, GetBitContext *gb)
+static void do_output_subblock(RA144Context *ractx, const uint16_t *lpc_coefs,
+ int gval, GetBitContext *gb)
{
uint16_t buffer_a[40];
uint16_t *block;
int m[3];
if (cba_idx) {
- cba_idx += HALFBLOCK - 1;
- rotate_block(ractx->adapt_cb, buffer_a, cba_idx);
- m[0] = irms(buffer_a, gval) >> 12;
+ cba_idx += BLOCKSIZE/2 - 1;
+ copy_and_dup(buffer_a, ractx->adapt_cb, cba_idx);
+ m[0] = (irms(buffer_a) * gval) >> 12;
} else {
m[0] = 0;
}
- m[1] = ((ftable1[cb1_idx] >> 4) * gval) >> 8;
- m[2] = ((ftable2[cb2_idx] >> 4) * gval) >> 8;
+ m[1] = (cb1_base[cb1_idx] * gval) >> 8;
+ m[2] = (cb2_base[cb2_idx] * gval) >> 8;
memmove(ractx->adapt_cb, ractx->adapt_cb + BLOCKSIZE,
- (BUFFERSIZE - BLOCKSIZE) * 2);
+ (BUFFERSIZE - BLOCKSIZE) * sizeof(*ractx->adapt_cb));
block = ractx->adapt_cb + BUFFERSIZE - BLOCKSIZE;
- add_wav(gain, cba_idx, m, buffer_a, etable1[cb1_idx], etable2[cb2_idx],
- block);
+ add_wav(block, gain, cba_idx, m, buffer_a,
+ cb1_vects[cb1_idx], cb2_vects[cb2_idx]);
- final(gsp, block, output_buffer, ractx->buffer, BLOCKSIZE);
+ memcpy(ractx->curr_sblock, ractx->curr_sblock + 40,
+ 10*sizeof(*ractx->curr_sblock));
+
+ if (ff_celp_lp_synthesis_filter(ractx->curr_sblock + 10, lpc_coefs,
+ block, BLOCKSIZE, 10, 1, 0xfff))
+ memset(ractx->curr_sblock, 0, 50*sizeof(*ractx->curr_sblock));
}
-static int dec1(int16_t *decsp, const int *data, const int *inp, int f)
+static void int_to_int16(int16_t *out, const int *inp)
{
int i;
- for (i=0; i<30; i++)
- *(decsp++) = *(inp++);
-
- return rms(data, f);
+ for (i=0; i < 30; i++)
+ *out++ = *inp++;
}
-static int eq(const int16_t *in, int *target)
+/**
+ * Evaluate the reflection coefficients from the filter coefficients.
+ * Does the inverse of the eval_coefs() function.
+ *
+ * @return 1 if one of the reflection coefficients is greater than
+ * 4095, 0 if not.
+ */
+static int eval_refl(int *refl, const int16_t *coefs, RA144Context *ractx)
{
- int retval = 0;
- int b, c, i;
- unsigned int u;
+ int b, i, j;
int buffer1[10];
int buffer2[10];
int *bp1 = buffer1;
int *bp2 = buffer2;
for (i=0; i < 10; i++)
- buffer2[i] = in[i];
-
- u = target[9] = bp2[9];
-
- if (u + 0x1000 > 0x1fff)
- return 0; /* We're screwed, might as well go out with a bang. :P */
+ buffer2[i] = coefs[i];
- for (c=8; c >= 0; c--) {
- if (u == 0x1000)
- u++;
+ refl[9] = bp2[9];
- if (u == 0xfffff000)
- u--;
+ if ((unsigned) bp2[9] + 0x1000 > 0x1fff) {
+ av_log(ractx, AV_LOG_ERROR, "Overflow. Broken sample?\n");
+ return 1;
+ }
- b = 0x1000-((u * u) >> 12);
+ for (i=8; i >= 0; i--) {
+ b = 0x1000-((bp2[i+1] * bp2[i+1]) >> 12);
- if (b == 0)
- b++;
+ if (!b)
+ b = -2;
- for (u=0; u<=c; u++)
- bp1[u] = ((bp2[u] - ((target[c+1] * bp2[c-u]) >> 12)) * (0x1000000 / b)) >> 12;
+ for (j=0; j <= i; j++)
+ bp1[j] = ((bp2[j] - ((refl[i+1] * bp2[i-j]) >> 12)) * (0x1000000 / b)) >> 12;
- target[c] = u = bp1[c];
+ if ((unsigned) bp1[i] + 0x1000 > 0x1fff)
+ return 1;
- if ((u + 0x1000) > 0x1fff)
- retval = 1;
+ refl[i] = bp1[i];
FFSWAP(int *, bp1, bp2);
}
- return retval;
+ return 0;
}
-static int dec2(RA144Context *ractx, int16_t *decsp, int block_num,
- int copynew, int f)
+static int interp(RA144Context *ractx, int16_t *out, int a,
+ int copyold, int energy)
{
int work[10];
- int a = block_num + 1;
int b = NBLOCKS - a;
- int x;
+ int i;
- // Interpolate block coefficients from the this frame forth block and
- // last frame forth block
- for (x=0; x<30; x++)
- decsp[x] = (a * ractx->lpc_coef[x] + b * ractx->lpc_coef_old[x])>> 2;
+ // Interpolate block coefficients from the this frame's forth block and
+ // last frame's forth block.
+ for (i=0; i<30; i++)
+ out[i] = (a * ractx->lpc_coef[0][i] + b * ractx->lpc_coef[1][i])>> 2;
- if (eq(decsp, work)) {
+ if (eval_refl(work, out, ractx)) {
// The interpolated coefficients are unstable, copy either new or old
- // coefficients
- if (copynew)
- return dec1(decsp, ractx->lpc_refl, ractx->lpc_coef, f);
- else
- return dec1(decsp, ractx->lpc_refl_old, ractx->lpc_coef_old, f);
+ // coefficients.
+ int_to_int16(out, ractx->lpc_coef[copyold]);
+ return rescale_rms(ractx->lpc_refl_rms[copyold], energy);
} else {
- return rms(work, f);
+ return rescale_rms(rms(work), energy);
}
}
-/* Uncompress one block (20 bytes -> 160*2 bytes) */
-static int ra144_decode_frame(AVCodecContext * avctx,
- void *vdata, int *data_size,
- const uint8_t * buf, int buf_size)
+/** Uncompress one block (20 bytes -> 160*2 bytes). */
+static int ra144_decode_frame(AVCodecContext * avctx, void *vdata,
+ int *data_size, const uint8_t *buf, int buf_size)
{
static const uint8_t sizes[10] = {6, 5, 5, 4, 4, 3, 3, 3, 3, 2};
- unsigned int gbuf1[4];
- uint16_t gbuf2[4][30];
- unsigned int a, c;
- int i;
+ unsigned int refl_rms[4]; // RMS of the reflection coefficients
+ uint16_t block_coefs[4][30]; // LPC coefficients of each sub-block
+ unsigned int lpc_refl[10]; // LPC reflection coefficients of the frame
+ int i, j;
int16_t *data = vdata;
unsigned int energy;
RA144Context *ractx = avctx->priv_data;
GetBitContext gb;
+ if (*data_size < 2*160)
+ return -1;
+
if(buf_size < 20) {
av_log(avctx, AV_LOG_ERROR,
"Frame too small (%d bytes). Truncated file?\n", buf_size);
+ *data_size = 0;
return buf_size;
}
init_get_bits(&gb, buf, 20 * 8);
for (i=0; i<10; i++)
- // "<< 1"? Doesn't this make one value out of two of the table useless?
- ractx->lpc_refl[i] = decodetable[i][get_bits(&gb, sizes[i]) << 1];
+ lpc_refl[i] = lpc_refl_cb[i][get_bits(&gb, sizes[i])];
- do_voice(ractx->lpc_refl, ractx->lpc_coef);
+ eval_coefs(ractx->lpc_coef[0], lpc_refl);
+ ractx->lpc_refl_rms[0] = rms(lpc_refl);
- energy = decodeval[get_bits(&gb, 5) << 1]; // Useless table entries?
- a = t_sqrt(energy*ractx->old_energy) >> 12;
+ energy = energy_tab[get_bits(&gb, 5)];
- gbuf1[0] = dec2(ractx, gbuf2[0], 0, 0, ractx->old_energy);
- gbuf1[1] = dec2(ractx, gbuf2[1], 1, energy > ractx->old_energy, a);
- gbuf1[2] = dec2(ractx, gbuf2[2], 2, 1, energy);
- gbuf1[3] = dec1(gbuf2[3], ractx->lpc_refl, ractx->lpc_coef, energy);
+ refl_rms[0] = interp(ractx, block_coefs[0], 1, 1, ractx->old_energy);
+ refl_rms[1] = interp(ractx, block_coefs[1], 2, energy <= ractx->old_energy,
+ t_sqrt(energy*ractx->old_energy) >> 12);
+ refl_rms[2] = interp(ractx, block_coefs[2], 3, 0, energy);
+ refl_rms[3] = rescale_rms(ractx->lpc_refl_rms[0], energy);
- /* do output */
- for (c=0; c<4; c++) {
- do_output_subblock(ractx, gbuf2[c], gbuf1[c], data, &gb);
+ int_to_int16(block_coefs[3], ractx->lpc_coef[0]);
- for (i=0; i<BLOCKSIZE; i++) {
- *data = av_clip_int16(*data << 2);
- data++;
- }
+ for (i=0; i < 4; i++) {
+ do_output_subblock(ractx, block_coefs[i], refl_rms[i], &gb);
+
+ for (j=0; j < BLOCKSIZE; j++)
+ *data++ = av_clip_int16(ractx->curr_sblock[j + 10] << 2);
}
ractx->old_energy = energy;
+ ractx->lpc_refl_rms[1] = ractx->lpc_refl_rms[0];
- FFSWAP(unsigned int *, ractx->lpc_refl_old, ractx->lpc_refl);
- FFSWAP(unsigned int *, ractx->lpc_coef_old, ractx->lpc_coef);
+ FFSWAP(unsigned int *, ractx->lpc_coef[0], ractx->lpc_coef[1]);
*data_size = 2*160;
return 20;
}
-
AVCodec ra_144_decoder =
{
"real_144",
NULL,
NULL,
ra144_decode_frame,
- .long_name = "RealAudio 1.0 (14.4K)",
+ .long_name = NULL_IF_CONFIG_SMALL("RealAudio 1.0 (14.4K)"),
};