ref: 5f078c13f02d9d3cbfd562d29b72a490a58822f0
parent: b4989014824433c9f048b0066a84b9f9e99611d2
author: menno <menno>
date: Thu Apr 18 14:08:07 EDT 2002
Some more ER stuff
--- a/libfaad/error.c
+++ b/libfaad/error.c
@@ -16,7 +16,7 @@
** along with this program; if not, write to the Free Software
** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
**
-** $Id: error.c,v 1.3 2002/02/25 19:58:33 menno Exp $
+** $Id: error.c,v 1.4 2002/04/18 18:08:06 menno Exp $
**/
#include "common.h"
@@ -30,5 +30,6 @@
"Negative scalefactor found, should be impossible",
"Unable to find ADTS syncword",
"Channel coupling not yet implemented",
- "Channel configuration not allowed in error resilient frame"
+ "Channel configuration not allowed in error resilient frame",
+ "Bit error in error resilient scalefactor decoding"
};
\ No newline at end of file
--- a/libfaad/syntax.c
+++ b/libfaad/syntax.c
@@ -16,7 +16,7 @@
** along with this program; if not, write to the Free Software
** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
**
-** $Id: syntax.c,v 1.10 2002/04/07 21:26:04 menno Exp $
+** $Id: syntax.c,v 1.11 2002/04/18 18:08:07 menno Exp $
**/
/*
@@ -588,6 +588,72 @@
}
/*
+ * decode_scale_factors()
+ * decodes the scalefactors from the bitstream
+ */
+static uint8_t decode_scale_factors(ic_stream *ics, bitfile *ld)
+{+ uint8_t g, sfb;
+ int8_t t;
+ int8_t noise_pcm_flag = 1;
+
+ int16_t scale_factor = ics->global_gain;
+ int16_t is_position = 0;
+ int16_t noise_energy = ics->global_gain - 90;
+
+ for (g = 0; g < ics->num_window_groups; g++)
+ {+ for (sfb = 0; sfb < ics->max_sfb; sfb++)
+ {+ switch (ics->sfb_cb[g][sfb])
+ {+ case ZERO_HCB: /* zero book */
+ ics->scale_factors[g][sfb] = 0;
+ break;
+ case INTENSITY_HCB: /* intensity books */
+ case INTENSITY_HCB2:
+
+ /* decode intensity position */
+ t = huffman_scale_factor(ld) - 60;
+ is_position += t;
+ ics->scale_factors[g][sfb] = is_position;
+
+ break;
+ case NOISE_HCB: /* noise books */
+
+ /* decode noise energy */
+ if (noise_pcm_flag)
+ {+ noise_pcm_flag = 0;
+ t = faad_getbits(ld, 9
+ DEBUGVAR(1,73,"scale_factor_data(): first noise")) - 256;
+ } else {+ t = huffman_scale_factor(ld) - 60;
+ }
+ noise_energy += t;
+ ics->scale_factors[g][sfb] = noise_energy;
+
+ break;
+ case BOOKSCL: /* invalid books */
+ return 3;
+ default: /* spectral books */
+
+ /* decode scale factor */
+ t = huffman_scale_factor(ld) - 60;
+ scale_factor += t;
+ if (scale_factor < 0)
+ return 4;
+ ics->scale_factors[g][sfb] = scale_factor;
+
+ break;
+ }
+ }
+ }
+
+ return 0;
+}
+
+/*
All scalefactors (and also the stereo positions and pns energies) are
transmitted using Huffman coded DPCM relative to the previous active
scalefactor (respectively previous stereo position or previous pns energy,
@@ -605,68 +671,10 @@
if (!aacScalefactorDataResilienceFlag)
{#endif
- uint8_t g, sfb;
- int8_t t;
- uint8_t noise_pcm_flag = 1;
- int16_t scale_factor = ics->global_gain;
- int16_t is_position = 0;
- int16_t noise_energy = ics->global_gain - 90;
-
- for (g = 0; g < ics->num_window_groups; g++)
- {- for (sfb = 0; sfb < ics->max_sfb; sfb++)
- {- switch (ics->sfb_cb[g][sfb])
- {- case ZERO_HCB: /* zero book */
- ics->scale_factors[g][sfb] = 0;
- break;
- case INTENSITY_HCB: /* intensity books */
- case INTENSITY_HCB2:
-
- /* decode intensity position */
- t = huffman_scale_factor(ld) - 60;
- is_position += t;
- ics->scale_factors[g][sfb] = is_position;
-
- break;
- case NOISE_HCB: /* noise books */
-
- /* decode noise energy */
- if (noise_pcm_flag)
- {- noise_pcm_flag = 0;
- t = faad_getbits(ld, 9
- DEBUGVAR(1,73,"scale_factor_data(): first noise")) - 256;
- } else {- t = huffman_scale_factor(ld) - 60;
- }
- noise_energy += t;
- ics->scale_factors[g][sfb] = noise_energy;
-
- break;
- case BOOKSCL: /* invalid books */
- return 3;
- default: /* spectral books */
-
- /* decode scale factor */
- t = huffman_scale_factor(ld) - 60;
- scale_factor += t;
- if (scale_factor < 0)
- return 4;
- ics->scale_factors[g][sfb] = scale_factor;
-
- break;
- }
- }
- }
-
- return 0;
+ return decode_scale_factors(ics, ld);
#ifdef ERROR_RESILIENCE
} else {- uint8_t g, sfb;
- uint8_t intensity_used = 0;
- uint8_t noise_used = 0;
+ uint32_t bits_used, length_of_rvlc_sf;
uint8_t bits = 11;
sf_concealment = faad_get1bit(ld
@@ -681,39 +689,21 @@
length_of_rvlc_sf = faad_getbits(ld, bits
DEBUGVAR(1,151,"scale_factor_data(): length_of_rvlc_sf"));
- for (g = 0; g < num_window_groups; g++)
- {- for (sfb = 0; sfb < max_sfb; sfb++)
- {- if (sect_cb[g][sfb] != ZERO_HCB)
- {- if (is_intensity(g, sfb))
- {- intensity_used = 1;
- rvlc_cod_sf[dpcm_is_position[g][sfb]]; 1..9 vlclbf
- } else {- if (is_noise(g,sfb))
- {- if (!noise_used)
- {- noise_used = 1;
- dpcm_noise_nrg[g][sfb] = faad_getbits(ld, 9
- DEBUGVAR(1,152,"scale_factor_data(): dpcm_noise_nrg"));
- } else {- rvlc_cod_sf[dpcm_noise_nrg[g][sfb]]; 1..9 vlclbf
- }
- } else {- rvlc_cod_sf[dpcm_sf[g][sfb]]; 1..9 vlclbf
- }
- }
- }
- }
- }
+ /* check how many bits are used in decoing the scalefactors
+ A better solution would be to read length_of_rvlc_sf ahead
+ in a buffer and use that to decode the scale factors
+ There's work ahead :-)
+ */
+ bits_used = faad_get_processed_bits(ld);
+ decode_scale_factors(ics, ld);
+ bits_used = faad_get_processed_bits(ld) - bits_used;
- if (intensity_used)
- {- rvlc_cod_sf[dpcm_is_last_position]; 1..9 vlclbf
- }
+ /* return an error if the number of decoded bits is not correct
+ FAAD should be able to recover from this, for example by
+ setting all scalefactors to 0 (muting the frame)
+ */
+ if (bits_used != length_of_rvlc_sf)
+ return 8;
sf_escapes_present; 1 uimsbf