As per ETSI TS 102 114 V1.4.1 specifiction.
---
libavcodec/dcadata.h | 46 +++++++++++++++++++
libavcodec/dcadec.c | 126 +++++++++++++++++++++++++++++++++++++++++++--------
2 files changed, 154 insertions(+), 18 deletions(-)
diff --git a/libavcodec/dcadata.h b/libavcodec/dcadata.h
index c4841fb..156a2c3 100644
--- a/libavcodec/dcadata.h
+++ b/libavcodec/dcadata.h
@@ -7505,6 +7505,52 @@ DECLARE_ALIGNED(16, static const float, lfe_fir_128)[] =
0.01724460535, 0.47964480519, 0.48503074050, 0.01805862412,
};
+/*
+ * D.11 Look-up Table for Downmix Scale Factors
+ *
+ * Note that the range of the entries in DmixTable[] is between -60 dB and 0 dB
+ * with addition of -inf (|DMixCoeff| = 0), which is coded with a DmixCode = 0.
+ * Furthermore, the range [-60 to 0] is subdivided into 3 regions, each with a
+ * different grid resolution:
+ *
+ * 1) [-60.000 to -30] with resolution of 0.500 dB
+ * 2) [-29.750 to -15] with resolution of 0.250 dB
+ * 3) [-14.875 to 0] with resolution of 0.125 dB
+ */
+static const float dca_dmixtable[241] = {
+ 0.001000, 0.001059, 0.001122, 0.001189, 0.001259, 0.001334, 0.001413,
0.001496,
+ 0.001585, 0.001679, 0.001778, 0.001884, 0.001995, 0.002113, 0.002239,
0.002371,
+ 0.002512, 0.002661, 0.002818, 0.002985, 0.003162, 0.003350, 0.003548,
0.003758,
+ 0.003981, 0.004217, 0.004467, 0.004732, 0.005012, 0.005309, 0.005623,
0.005957,
+ 0.006310, 0.006683, 0.007079, 0.007499, 0.007943, 0.008414, 0.008913,
0.009441,
+ 0.010000, 0.010593, 0.011220, 0.011885, 0.012589, 0.013335, 0.014125,
0.014962,
+ 0.015849, 0.016788, 0.017783, 0.018836, 0.019953, 0.021135, 0.022387,
0.023714,
+ 0.025119, 0.026607, 0.028184, 0.029854, 0.031623, 0.032546, 0.033497,
0.034475,
+ 0.035481, 0.036517, 0.037584, 0.038681, 0.039811, 0.040973, 0.042170,
0.043401,
+ 0.044668, 0.045973, 0.047315, 0.048697, 0.050119, 0.051582, 0.053088,
0.054639,
+ 0.056234, 0.057876, 0.059566, 0.061306, 0.063096, 0.064938, 0.066834,
0.068786,
+ 0.070795, 0.072862, 0.074989, 0.077179, 0.079433, 0.081752, 0.084140,
0.086596,
+ 0.089125, 0.091728, 0.094406, 0.097163, 0.100000, 0.102920, 0.105925,
0.109018,
+ 0.112202, 0.115478, 0.118850, 0.122321, 0.125893, 0.129569, 0.133352,
0.137246,
+ 0.141254, 0.145378, 0.149624, 0.153993, 0.158489, 0.163117, 0.167880,
0.172783,
+ 0.177828, 0.180406, 0.183021, 0.185674, 0.188365, 0.191095, 0.193865,
0.196675,
+ 0.199526, 0.202418, 0.205353, 0.208329, 0.211349, 0.214412, 0.217520,
0.220673,
+ 0.223872, 0.227117, 0.230409, 0.233749, 0.237137, 0.240575, 0.244062,
0.247600,
+ 0.251189, 0.254830, 0.258523, 0.262271, 0.266073, 0.269929, 0.273842,
0.277811,
+ 0.281838, 0.285924, 0.290068, 0.294273, 0.298538, 0.302866, 0.307256,
0.311709,
+ 0.316228, 0.320812, 0.325462, 0.330179, 0.334965, 0.339821, 0.344747,
0.349744,
+ 0.354813, 0.359956, 0.365174, 0.370467, 0.375837, 0.381285, 0.386812,
0.392419,
+ 0.398107, 0.403878, 0.409732, 0.415671, 0.421697, 0.427809, 0.434010,
0.440301,
+ 0.446684, 0.453158, 0.459727, 0.466391, 0.473151, 0.480010, 0.486968,
0.494026,
+ 0.501187, 0.508452, 0.515822, 0.523299, 0.530884, 0.538580, 0.546387,
0.554307,
+ 0.562341, 0.570493, 0.578762, 0.587151, 0.595662, 0.604296, 0.613056,
0.621942,
+ 0.630957, 0.640103, 0.649382, 0.658795, 0.668344, 0.678032, 0.687860,
0.697831,
+ 0.707107, 0.718208, 0.728618, 0.739180, 0.749894, 0.760764, 0.771792,
0.782979,
+ 0.794328, 0.805842, 0.817523, 0.829373, 0.841395, 0.853591, 0.865964,
0.878517,
+ 0.891251, 0.904170, 0.917276, 0.930572, 0.944061, 0.957745, 0.971628,
0.985712,
+ 1.000000,
+};
+
static const float dca_default_coeffs[10][5][2] = {
{ { 0.707946, 0.707946 },
}, // A
{ { 1.000000, 0.000000 }, { 0.000000, 1.000000 },
}, // A + B (dual mono)
diff --git a/libavcodec/dcadec.c b/libavcodec/dcadec.c
index 742e8ab..1143d22 100644
--- a/libavcodec/dcadec.c
+++ b/libavcodec/dcadec.c
@@ -339,6 +339,13 @@ typedef struct {
float downmix_coef[DCA_PRIM_CHANNELS_MAX][2]; ///< stereo
downmix coefficients
int dynrange_coef; ///< dynamic
range coefficient
+ /* Core substream's embedded downmix coefficients (cf. ETSI TS 102 114
V1.4.1)
+ * Input: primary audio channels (incl. LFE if present)
+ * Output: downmix audio channels (up to 4, no LFE) */
+ uint8_t core_downmix; ///< embedded
downmix coefficients available
+ uint8_t core_downmix_amode; ///< audio
channel arrangement of embedded downmix
+ uint16_t core_downmix_codes[DCA_PRIM_CHANNELS_MAX + 1][4]; ///< embedded
downmix coefficients (9-bit codes)
+
int high_freq_vq[DCA_PRIM_CHANNELS_MAX][DCA_SUBBANDS]; ///< VQ
encoded high frequency subbands
float lfe_data[2 * DCA_LFE_MAX * (DCA_BLOCKS_MAX + 4)]; ///< Low
frequency effect data
@@ -798,20 +805,40 @@ static int dca_subframe_header(DCAContext *s, int
base_channel, int block_index)
/* Stereo downmix coefficients */
if (!base_channel && s->prim_channels > 2) {
- int am = s->amode & DCA_CHANNEL_MASK;
- if (am >= FF_ARRAY_ELEMS(dca_default_coeffs)) {
- av_log(s->avctx, AV_LOG_ERROR,
- "Invalid channel mode %d\n", am);
- return AVERROR_INVALIDDATA;
- }
- if (s->prim_channels > FF_ARRAY_ELEMS(dca_default_coeffs[0])) {
- avpriv_request_sample(s->avctx, "Downmixing %d channels",
- s->prim_channels);
- return AVERROR_PATCHWELCOME;
- }
- for (j = base_channel; j < s->prim_channels; j++) {
- s->downmix_coef[j][0] = dca_default_coeffs[am][j][0];
- s->downmix_coef[j][1] = dca_default_coeffs[am][j][1];
+ // the decoder can only downmix to 2-channel, so we need to make sure
+ // embedded downmix coefficients are targeting 2-channel (if present)
+ // downmix coefficients for the LFE channel are ignored (not supported)
+ if (s->core_downmix && (s->core_downmix_amode == DCA_STEREO ||
+ s->core_downmix_amode == DCA_STEREO_TOTAL)) {
+ int sign, code;
+ for (j = base_channel; j < s->prim_channels; j++) {
+
+ sign = s->core_downmix_codes[j][0] & 0x100 ? 1 : -1;
+ code = s->core_downmix_codes[j][0] & 0x0FF;
+ s->downmix_coef[j][0] = (!code ? 0.0f :
+ sign * dca_dmixtable[code - 1]);
+
+ sign = s->core_downmix_codes[j][1] & 0x100 ? 1 : -1;
+ code = s->core_downmix_codes[j][1] & 0x0FF;
+ s->downmix_coef[j][1] = (!code ? 0.0f :
+ sign * dca_dmixtable[code - 1]);
+ }
+ } else {
+ int am = s->amode & DCA_CHANNEL_MASK;
+ if (am >= FF_ARRAY_ELEMS(dca_default_coeffs)) {
+ av_log(s->avctx, AV_LOG_ERROR,
+ "Invalid channel mode %d\n", am);
+ return AVERROR_INVALIDDATA;
+ }
+ if (s->prim_channels > FF_ARRAY_ELEMS(dca_default_coeffs[0])) {
+ avpriv_request_sample(s->avctx, "Downmixing %d channels",
+ s->prim_channels);
+ return AVERROR_PATCHWELCOME;
+ }
+ for (j = base_channel; j < s->prim_channels; j++) {
+ s->downmix_coef[j][0] = dca_default_coeffs[am][j][0];
+ s->downmix_coef[j][1] = dca_default_coeffs[am][j][1];
+ }
}
}
@@ -1292,7 +1319,7 @@ static int dca_filter_channels(DCAContext *s, int
block_index)
static int dca_subframe_footer(DCAContext *s, int base_channel)
{
- int aux_data_count = 0, i;
+ int in, out, aux_data_count, aux_data_end, reserved;
/*
* Unpack optional information
@@ -1303,11 +1330,74 @@ static int dca_subframe_footer(DCAContext *s, int
base_channel)
if (s->timestamp)
skip_bits_long(&s->gb, 32);
- if (s->aux_data)
+ if (s->aux_data) {
aux_data_count = get_bits(&s->gb, 6);
- for (i = 0; i < aux_data_count; i++)
- get_bits(&s->gb, 8);
+ // align (32-bit)
+ skip_bits_long(&s->gb, (-get_bits_count(&s->gb)) & 31);
+
+ aux_data_end = 8 * aux_data_count + get_bits_count(&s->gb);
+
+ if (get_bits_long(&s->gb, 32) != 0x9A1105A0) // nSYNCAUX
+ return AVERROR_INVALIDDATA;
+
+ if (get_bits1(&s->gb)) { // bAUXTimeStampFlag
+ avpriv_request_sample(s->avctx,
+ "Auxiliary Decode Time Stamp Flag");
+ // align (4-bit)
+ skip_bits(&s->gb, (-get_bits_count(&s->gb)) & 4);
+ // 44 bits: nMSByte (8), nMarker (4), nLSByte (28), nMarker (4)
+ skip_bits_long(&s->gb, 44);
+ }
+
+ if ((s->core_downmix = get_bits1(&s->gb))) {
+ switch (get_bits(&s->gb, 3)) {
+ case 0:
+ s->core_downmix_amode = DCA_MONO;
+ break;
+ case 1:
+ s->core_downmix_amode = DCA_STEREO;
+ break;
+ case 2:
+ s->core_downmix_amode = DCA_STEREO_TOTAL;
+ break;
+ case 3:
+ s->core_downmix_amode = DCA_3F;
+ break;
+ case 4:
+ s->core_downmix_amode = DCA_2F1R;
+ break;
+ case 5:
+ s->core_downmix_amode = DCA_2F2R;
+ break;
+ case 6:
+ s->core_downmix_amode = DCA_3F1R;
+ break;
+ default:
+ return AVERROR_INVALIDDATA;
+ }
+ for (out = 0; out < dca_channels[s->core_downmix_amode];
out++) {
+ for (in = 0; in < s->prim_channels + !!s->lfe; in++) {
+ uint16_t tmp = get_bits(&s->gb, 9);
+ if ((tmp & 0xFF) > 241)
+ return AVERROR_INVALIDDATA;
+ s->core_downmix_codes[in][out] = tmp;
+ }
+ }
+ }
+
+ align_get_bits(&s->gb); // byte align
+ skip_bits(&s->gb, 16); // nAUXCRC16
+
+ // additional data (reserved, cf. ETSI TS 102 114 V1.4.1)
+ if ((reserved = (aux_data_end - get_bits_count(&s->gb))) < 0)
+ return AVERROR_INVALIDDATA;
+ else if (reserved) {
+ avpriv_request_sample(s->avctx,
+ "Core auxiliary data reserved content");
+ skip_bits_long(&s->gb, reserved);
+ }
+ }
if (s->crc_present && s->dynrange)
get_bits(&s->gb, 16);
--
1.8.3.4 (Apple Git-47)
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