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fixed layer1/2 overflow if very loud sound - fixed broken free format decoding to pass all mpeg audio standard decoding tests (please avoid patching the parser without having all test streams available - contact me if necessary)

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Originally committed as revision 634 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Fabrice Bellard 2002-06-01 14:34:29 +00:00
parent 31def22984
commit 8155233413
1 changed files with 47 additions and 37 deletions
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84
libavcodec/mpegaudiodec.c
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@ -28,7 +28,9 @@
/* define USE_HIGHPRECISION to have a bit exact (but slower) mpeg /* define USE_HIGHPRECISION to have a bit exact (but slower) mpeg
audio decoder */ audio decoder */
//#define USE_HIGHPRECISION #ifdef CONFIG_MPEGAUDIO_HP
#define USE_HIGHPRECISION
#endif
#ifdef USE_HIGHPRECISION #ifdef USE_HIGHPRECISION
#define FRAC_BITS 23 /* fractional bits for sb_samples and dct */ #define FRAC_BITS 23 /* fractional bits for sb_samples and dct */
@ -149,9 +151,9 @@ static INT32 scale_factor_mult[15][3];
{ FIXR(1.0 * (v)), FIXR(0.7937005259 * (v)), FIXR(0.6299605249 * (v)) } { FIXR(1.0 * (v)), FIXR(0.7937005259 * (v)), FIXR(0.6299605249 * (v)) }
static INT32 scale_factor_mult2[3][3] = { static INT32 scale_factor_mult2[3][3] = {
SCALE_GEN(1.0 / 3.0), /* 3 steps */ SCALE_GEN(4.0 / 3.0), /* 3 steps */
SCALE_GEN(1.0 / 5.0), /* 5 steps */ SCALE_GEN(4.0 / 5.0), /* 5 steps */
SCALE_GEN(1.0 / 9.0), /* 9 steps */ SCALE_GEN(4.0 / 9.0), /* 9 steps */
}; };
/* 2^(n/4) */ /* 2^(n/4) */
@ -176,7 +178,8 @@ static inline int l1_unscale(int n, int mant, int scale_factor)
shift >>= 2; shift >>= 2;
val = MUL64(mant + (-1 << n) + 1, scale_factor_mult[n-1][mod]); val = MUL64(mant + (-1 << n) + 1, scale_factor_mult[n-1][mod]);
shift += n; shift += n;
return (int)((val + (1 << (shift - 1))) >> shift); /* NOTE: at this point, 1 <= shift >= 21 + 15 */
return (int)((val + (1LL << (shift - 1))) >> shift);
} }
static inline int l2_unscale_group(int steps, int mant, int scale_factor) static inline int l2_unscale_group(int steps, int mant, int scale_factor)
@ -186,9 +189,12 @@ static inline int l2_unscale_group(int steps, int mant, int scale_factor)
shift = scale_factor_modshift[scale_factor]; shift = scale_factor_modshift[scale_factor];
mod = shift & 3; mod = shift & 3;
shift >>= 2; shift >>= 2;
/* XXX: store the result directly */
val = (2 * (mant - (steps >> 1))) * scale_factor_mult2[steps >> 2][mod]; val = (mant - (steps >> 1)) * scale_factor_mult2[steps >> 2][mod];
return (val + (1 << (shift - 1))) >> shift; /* NOTE: at this point, 0 <= shift <= 21 */
if (shift > 0)
val = (val + (1 << (shift - 1))) >> shift;
return val;
} }
/* compute value^(4/3) * 2^(exponent/4). It normalized to FRAC_BITS */ /* compute value^(4/3) * 2^(exponent/4). It normalized to FRAC_BITS */
@ -280,7 +286,7 @@ static int int_pow(int i, int *exp_ptr)
eq--; eq--;
} }
/* now POW_FRAC_ONE <= a < 2 * POW_FRAC_ONE */ /* now POW_FRAC_ONE <= a < 2 * POW_FRAC_ONE */
#if (POW_FRAC_BITS - 1) > FRAC_BITS #if POW_FRAC_BITS > FRAC_BITS
a = (a + (1 << (POW_FRAC_BITS - FRAC_BITS - 1))) >> (POW_FRAC_BITS - FRAC_BITS); a = (a + (1 << (POW_FRAC_BITS - FRAC_BITS - 1))) >> (POW_FRAC_BITS - FRAC_BITS);
/* correct overflow */ /* correct overflow */
if (a >= 2 * (1 << FRAC_BITS)) { if (a >= 2 * (1 << FRAC_BITS)) {
@ -303,12 +309,8 @@ static int decode_init(AVCodecContext * avctx)
for(i=0;i<64;i++) { for(i=0;i<64;i++) {
int shift, mod; int shift, mod;
/* 1.0 (i = 3) is normalized to 2 ^ FRAC_BITS */ /* 1.0 (i = 3) is normalized to 2 ^ FRAC_BITS */
shift = (i / 3) - 1; shift = (i / 3);
mod = i % 3; mod = i % 3;
#if FRAC_BITS <= 15
if (shift > 31)
shift = 31;
#endif
scale_factor_modshift[i] = mod | (shift << 2); scale_factor_modshift[i] = mod | (shift << 2);
} }
@ -317,9 +319,9 @@ static int decode_init(AVCodecContext * avctx)
int n, norm; int n, norm;
n = i + 2; n = i + 2;
norm = ((INT64_C(1) << n) * FRAC_ONE) / ((1 << n) - 1); norm = ((INT64_C(1) << n) * FRAC_ONE) / ((1 << n) - 1);
scale_factor_mult[i][0] = MULL(FIXR(1.0), norm); scale_factor_mult[i][0] = MULL(FIXR(1.0 * 2.0), norm);
scale_factor_mult[i][1] = MULL(FIXR(0.7937005259), norm); scale_factor_mult[i][1] = MULL(FIXR(0.7937005259 * 2.0), norm);
scale_factor_mult[i][2] = MULL(FIXR(0.6299605249), norm); scale_factor_mult[i][2] = MULL(FIXR(0.6299605249 * 2.0), norm);
dprintf("%d: norm=%x s=%x %x %x\n", dprintf("%d: norm=%x s=%x %x %x\n",
i, norm, i, norm,
scale_factor_mult[i][0], scale_factor_mult[i][0],
@ -809,6 +811,8 @@ static void synth_filter(MPADecodeContext *s1,
for(j=0;j<32;j++) { for(j=0;j<32;j++) {
v = tmp[j]; v = tmp[j];
#if FRAC_BITS <= 15 #if FRAC_BITS <= 15
/* NOTE: can cause a loss in precision if very high amplitude
sound */
if (v > 32767) if (v > 32767)
v = 32767; v = 32767;
else if (v < -32768) else if (v < -32768)
@ -1069,11 +1073,10 @@ static int decode_header(MPADecodeContext *s, UINT32 header)
/* extract frequency */ /* extract frequency */
sample_rate_index = (header >> 10) & 3; sample_rate_index = (header >> 10) & 3;
sample_rate = mpa_freq_tab[sample_rate_index] >> (s->lsf + mpeg25); sample_rate = mpa_freq_tab[sample_rate_index] >> (s->lsf + mpeg25);
if (sample_rate == 0)
return 1;
sample_rate_index += 3 * (s->lsf + mpeg25); sample_rate_index += 3 * (s->lsf + mpeg25);
s->sample_rate_index = sample_rate_index; s->sample_rate_index = sample_rate_index;
s->error_protection = ((header >> 16) & 1) ^ 1; s->error_protection = ((header >> 16) & 1) ^ 1;
s->sample_rate = sample_rate;
bitrate_index = (header >> 12) & 0xf; bitrate_index = (header >> 12) & 0xf;
padding = (header >> 9) & 1; padding = (header >> 9) & 1;
@ -1131,7 +1134,6 @@ static int decode_header(MPADecodeContext *s, UINT32 header)
break; break;
} }
} }
s->sample_rate = sample_rate;
#if defined(DEBUG) #if defined(DEBUG)
printf("layer%d, %d Hz, %d kbits/s, ", printf("layer%d, %d Hz, %d kbits/s, ",
@ -1962,10 +1964,19 @@ void sample_dump(int fnum, INT32 *tab, int n)
{ {
static FILE *files[16], *f; static FILE *files[16], *f;
char buf[512]; char buf[512];
int i;
INT32 v;
f = files[fnum]; f = files[fnum];
if (!f) { if (!f) {
sprintf(buf, "/tmp/out%d.pcm", fnum); sprintf(buf, "/tmp/out%d.%s.pcm",
fnum,
#ifdef USE_HIGHPRECISION
"hp"
#else
"lp"
#endif
);
f = fopen(buf, "w"); f = fopen(buf, "w");
if (!f) if (!f)
return; return;
@ -1973,18 +1984,20 @@ void sample_dump(int fnum, INT32 *tab, int n)
} }
if (fnum == 0) { if (fnum == 0) {
int i;
static int pos = 0; static int pos = 0;
printf("pos=%d\n", pos); printf("pos=%d\n", pos);
for(i=0;i<n;i++) { for(i=0;i<n;i++) {
printf(" %f", (double)tab[i] / 32768.0); printf(" %0.4f", (double)tab[i] / FRAC_ONE);
if ((i % 18) == 17) if ((i % 18) == 17)
printf("\n"); printf("\n");
} }
pos += n; pos += n;
} }
for(i=0;i<n;i++) {
fwrite(tab, 1, n * sizeof(INT32), f); /* normalize to 23 frac bits */
v = tab[i] << (23 - FRAC_BITS);
fwrite(&v, 1, sizeof(INT32), f);
}
} }
#endif #endif
@ -2273,11 +2286,11 @@ static int mp_decode_layer3(MPADecodeContext *s)
sample_dump(0, g->sb_hybrid, 576); sample_dump(0, g->sb_hybrid, 576);
#endif #endif
compute_antialias(s, g); compute_antialias(s, g);
#ifdef DEBUG #if defined(DEBUG)
sample_dump(1, g->sb_hybrid, 576); sample_dump(1, g->sb_hybrid, 576);
#endif #endif
compute_imdct(s, g, &s->sb_samples[ch][18 * gr][0], s->mdct_buf[ch]); compute_imdct(s, g, &s->sb_samples[ch][18 * gr][0], s->mdct_buf[ch]);
#ifdef DEBUG #if defined(DEBUG)
sample_dump(2, &s->sb_samples[ch][18 * gr][0], 576); sample_dump(2, &s->sb_samples[ch][18 * gr][0], 576);
#endif #endif
} }
@ -2389,17 +2402,14 @@ static int decode_frame(AVCodecContext * avctx,
s->free_format_frame_size = 0; s->free_format_frame_size = 0;
} else { } else {
if (decode_header(s, header) == 1) { if (decode_header(s, header) == 1) {
/* free format: compute frame size */ /* free format: prepare to compute frame size */
s->frame_size = -1; s->frame_size = -1;
memcpy(s->inbuf, s->inbuf + 1, s->inbuf_ptr - s->inbuf - 1);
s->inbuf_ptr--;
} else {
/* update codec info */
avctx->sample_rate = s->sample_rate;
avctx->channels = s->nb_channels;
avctx->bit_rate = s->bit_rate;
avctx->frame_size = s->frame_size;
} }
/* update codec info */
avctx->sample_rate = s->sample_rate;
avctx->channels = s->nb_channels;
avctx->bit_rate = s->bit_rate;
avctx->frame_size = s->frame_size;
} }
} }
} else if (s->frame_size == -1) { } else if (s->frame_size == -1) {