* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
+/*
+ * There are several features of E-AC-3 that this decoder does not yet support.
+ *
+ * Spectral Extension
+ * There is a patch to get this working for the two samples we have that
+ * use it, but it needs some minor changes in order to be accepted.
+ *
+ * Enhanced Coupling
+ * No known samples exist. If any ever surface, this feature should not be
+ * too difficult to implement.
+ *
+ * Reduced Sample Rates
+ * No known samples exist. The spec also does not give clear information
+ * on how this is to be implemented.
+ *
+ * Dependent Streams
+ * Only the independent stream is currently decoded. Any dependent
+ * streams are skipped. We have only come across two examples of this, and
+ * they are both just test streams, one for HD-DVD and the other for
+ * Blu-ray.
+ *
+ * Transient Pre-noise Processing
+ * This is side information which a decoder should use to reduce artifacts
+ * caused by transients. There are samples which are known to have this
+ * information, but this decoder currently ignores it.
+ */
+
+
#include "avcodec.h"
+#include "internal.h"
+#include "aac_ac3_parser.h"
#include "ac3.h"
#include "ac3_parser.h"
#include "ac3dec.h"
#define EAC3_SR_CODE_REDUCED 3
-
-void ff_eac3_apply_spectral_extension(AC3DecodeContext *s)
-{
- int bin, bnd, ch, i;
- int wrapflag[SPX_MAX_BANDS]={0,}, num_copy_sections, copy_sizes[SPX_MAX_BANDS];
- int rms_energy[SPX_MAX_BANDS];
-
- /* Set copy index mapping table. Set wrap flags to apply a notch filter at
- wrap points later on. */
- bin = s->spx_copy_start_freq;
- num_copy_sections = 0;
- for (bnd = 0; bnd < s->num_spx_bands; bnd++) {
- int bandsize = s->spx_band_sizes[bnd];
- if ((bin + bandsize) > s->spx_start_freq) {
- copy_sizes[num_copy_sections++] = bin - s->spx_copy_start_freq;
- bin = s->spx_copy_start_freq;
- wrapflag[bnd] = 1;
- }
- for (i = 0; i < bandsize; i++) {
- if (bin == s->spx_start_freq) {
- copy_sizes[num_copy_sections++] = bin - s->spx_copy_start_freq;
- bin = s->spx_copy_start_freq;
- }
- bin++;
- }
- }
- copy_sizes[num_copy_sections++] = bin - s->spx_copy_start_freq;
-
- for (ch = 1; ch <= s->fbw_channels; ch++) {
- if (!s->channel_in_spx[ch])
- continue;
-
- /* Copy coeffs from normal bands to extension bands */
- bin = s->spx_start_freq;
- for (bnd = 0; bnd < num_copy_sections; bnd++) {
- memcpy(&s->fixed_coeffs[ch][bin],
- &s->fixed_coeffs[ch][s->spx_copy_start_freq],
- copy_sizes[bnd]*sizeof(int));
- bin += copy_sizes[bnd];
- }
-
- /* Calculate RMS energy for each SPX band. */
- bin = s->spx_start_freq;
- for (bnd = 0; bnd < s->num_spx_bands; bnd++) {
- int bandsize = s->spx_band_sizes[bnd];
- int64_t accum = 0;
- for (i = 0; i < bandsize; i++) {
- int64_t coeff = s->fixed_coeffs[ch][bin++];
- accum += coeff * coeff;
- }
- rms_energy[bnd] = ff_sqrt((accum >> 15) / bandsize) * M_SQRT_POW2_15;
- }
-
- /* Apply a notch filter at transitions between normal and extension
- bands and at all wrap points. */
- if (s->spx_atten_code[ch] >= 0) {
- const int32_t *atten_tab = ff_eac3_spx_atten_tab[s->spx_atten_code[ch]];
- /* apply notch filter at baseband / extension region border */
- bin = s->spx_start_freq - 2;
- for (i = 0; i < 5; i++) {
- s->fixed_coeffs[ch][bin] = ((int64_t)atten_tab[2-abs(i-2)] *
- (int64_t)s->fixed_coeffs[ch][bin]) >> 23;
- bin++;
- }
- /* apply notch at all other wrap points */
- bin += s->spx_band_sizes[0];
- for (bnd = 1; bnd < s->num_spx_bands; bnd++) {
- if (wrapflag[bnd]) {
- bin -= 5;
- for (i = 0; i < 5; i++) {
- s->fixed_coeffs[ch][bin] = (atten_tab[2-abs(i-2)] *
- (int64_t)s->fixed_coeffs[ch][bin]) >> 23;
- bin++;
- }
- }
- bin += s->spx_band_sizes[bnd];
- }
- }
-
- /* Apply noise-blended coefficient scaling based on previously
- calculated RMS energy, blending factors, and SPX coordinates for
- each band. */
- bin = s->spx_start_freq;
- for (bnd = 0; bnd < s->num_spx_bands; bnd++) {
- int64_t nscale, sscale, spxco;
- nscale = (s->spx_noise_blend [ch][bnd] * rms_energy[bnd]) >> 23;
- nscale = (nscale * 14529495) >> 23;
- sscale = s->spx_signal_blend[ch][bnd];
- spxco = s->spx_coords[ch][bnd];
- for (i = 0; i < s->spx_band_sizes[bnd]; i++) {
- int64_t noise = (nscale * (((int)av_lfg_get(&s->dith_state))>>8)) >> 23;
- int64_t signal = (sscale * s->fixed_coeffs[ch][bin]) >> 23;
- s->fixed_coeffs[ch][bin++] = ((noise + signal) * spxco) >> 23;
- }
- }
- }
-}
-
/** lrint(M_SQRT2*cos(2*M_PI/12)*(1<<23)) */
#define COEFF_0 10273905LL
application can select from. each independent stream can also contain
dependent streams which are used to add or replace channels. */
if (s->frame_type == EAC3_FRAME_TYPE_DEPENDENT) {
- av_log_missing_feature(s->avctx, "Dependent substream decoding", 1);
- return AC3_PARSE_ERROR_FRAME_TYPE;
+ ff_log_missing_feature(s->avctx, "Dependent substream decoding", 1);
+ return AAC_AC3_PARSE_ERROR_FRAME_TYPE;
} else if (s->frame_type == EAC3_FRAME_TYPE_RESERVED) {
av_log(s->avctx, AV_LOG_ERROR, "Reserved frame type\n");
- return AC3_PARSE_ERROR_FRAME_TYPE;
+ return AAC_AC3_PARSE_ERROR_FRAME_TYPE;
}
/* The substream id indicates which substream this frame belongs to. each
associated to an independent stream have matching substream id's. */
if (s->substreamid) {
/* only decode substream with id=0. skip any additional substreams. */
- av_log_missing_feature(s->avctx, "Additional substreams", 1);
- return AC3_PARSE_ERROR_FRAME_TYPE;
+ ff_log_missing_feature(s->avctx, "Additional substreams", 1);
+ return AAC_AC3_PARSE_ERROR_FRAME_TYPE;
}
if (s->bit_alloc_params.sr_code == EAC3_SR_CODE_REDUCED) {
rates in bit allocation. The best assumption would be that it is
handled like AC-3 DolbyNet, but we cannot be sure until we have a
sample which utilizes this feature. */
- av_log_missing_feature(s->avctx, "Reduced sampling rates", 1);
+ ff_log_missing_feature(s->avctx, "Reduced sampling rates", 1);
return -1;
}
skip_bits(gbc, 5); // skip bitstream id
}
/* spectral extension attenuation data */
- for (ch = 1; ch <= s->fbw_channels; ch++) {
- if (parse_spx_atten_data && get_bits1(gbc))
- s->spx_atten_code[ch] = get_bits(gbc, 5);
- else
- s->spx_atten_code[ch] = -1;
- }
+ if (parse_spx_atten_data) {
+ ff_log_missing_feature(s->avctx, "Spectral extension attenuation", 1);
+ for (ch = 1; ch <= s->fbw_channels; ch++) {
+ if (get_bits1(gbc)) { // channel has spx attenuation
+ skip_bits(gbc, 5); // skip spx attenuation code
+ }
+ }
+ }
/* block start information */
if (s->num_blocks > 1 && get_bits1(gbc)) {
The spec does not say what this data is or what it's used for.
It is likely the offset of each block within the frame. */
int block_start_bits = (s->num_blocks-1) * (4 + av_log2(s->frame_size-2));
- skip_bits(gbc, block_start_bits);
+ skip_bits_long(gbc, block_start_bits);
+ ff_log_missing_feature(s->avctx, "Block start info", 1);
}
/* syntax state initialization */
for (ch = 1; ch <= s->fbw_channels; ch++) {
- s->first_spx_coords[ch] = 1;
s->first_cpl_coords[ch] = 1;
}
s->first_cpl_leak = 1;
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