/* * NellyMoser audio decoder * Copyright (c) 2007 a840bda5870ba11f19698ff6eb9581dfb0f95fa5, * 539459aeb7d425140b62a3ec7dbf6dc8e408a306, and * 520e17cd55896441042b14df2566a6eb610ed444 * Copyright (c) 2007 Loic Minier <lool at dooz.org> * Benjamin Larsson * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER * DEALINGS IN THE SOFTWARE. */ /** * @file nellymoserdec.c * The 3 alphanumeric copyright notices are md5summed they are from the original * implementors. The original code is available from http://code.google.com/p/nelly2pcm/ */ #include "avcodec.h" #include "random.h" #include "dsputil.h" #define ALT_BITSTREAM_READER_LE #include "bitstream.h" #define NELLY_BANDS 23 #define NELLY_BLOCK_LEN 64 #define NELLY_HEADER_BITS 116 #define NELLY_DETAIL_BITS 198 #define NELLY_BUF_LEN 128 #define NELLY_FILL_LEN 124 #define NELLY_BIT_CAP 6 #define NELLY_BASE_OFF 4228 #define NELLY_BASE_SHIFT 19 #define NELLY_SAMPLES (2 * NELLY_BUF_LEN) static const float dequantization_table[127] = { 0.0000000000,-0.8472560048, 0.7224709988, -1.5247479677, -0.4531480074, 0.3753609955, 1.4717899561, -1.9822579622, -1.1929379702, -0.5829370022, -0.0693780035, 0.3909569979,0.9069200158, 1.4862740040, 2.2215409279, -2.3887870312, -1.8067539930, -1.4105420113, -1.0773609877, -0.7995010018,-0.5558109879, -0.3334020078, -0.1324490011, 0.0568020009, 0.2548770010, 0.4773550034, 0.7386850119, 1.0443060398, 1.3954459429, 1.8098750114, 2.3918759823,-2.3893830776, -1.9884680510, -1.7514040470, -1.5643119812, -1.3922129869,-1.2164649963, -1.0469499826, -0.8905100226, -0.7645580173, -0.6454579830, -0.5259280205, -0.4059549868, -0.3029719889, -0.2096900046, -0.1239869967, -0.0479229987, 0.0257730000, 0.1001340002, 0.1737180054, 0.2585540116, 0.3522900045, 0.4569880068, 0.5767750144, 0.7003160119, 0.8425520062, 1.0093879700, 1.1821349859, 1.3534560204, 1.5320819616, 1.7332619429, 1.9722349644, 2.3978140354, -2.5756309032, -2.0573320389, -1.8984919786, -1.7727810144, -1.6662600040, -1.5742180347, -1.4993319511, -1.4316639900, -1.3652280569, -1.3000990152, -1.2280930281, -1.1588579416, -1.0921250582, -1.0135740042, -0.9202849865, -0.8287050128, -0.7374889851, -0.6447759867, -0.5590940118, -0.4857139885, -0.4110319912, -0.3459700048, -0.2851159871, -0.2341620028, -0.1870580018, -0.1442500055, -0.1107169986, -0.0739680007, -0.0365610011, -0.0073290002, 0.0203610007, 0.0479039997, 0.0751969963, 0.0980999991, 0.1220389977, 0.1458999962, 0.1694349945, 0.1970459968, 0.2252430022, 0.2556869984, 0.2870100141, 0.3197099864, 0.3525829911, 0.3889069855, 0.4334920049, 0.4769459963, 0.5204820037, 0.5644530058, 0.6122040153, 0.6685929894, 0.7341650128, 0.8032159805, 0.8784040213, 0.9566209912, 1.0397069454, 1.1293770075, 1.2211159468, 1.3080279827, 1.4024800062, 1.5056819916, 1.6227730513, 1.7724959850, 1.9430880547, 2.2903931141 }; static const uint8_t nelly_band_sizes_table[NELLY_BANDS] = { 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 4, 4, 5, 6, 6, 7, 8, 9, 10, 12, 14, 15 }; static const uint16_t nelly_init_table[64] = { 3134, 5342, 6870, 7792, 8569, 9185, 9744, 10191, 10631, 11061, 11434, 11770, 12116, 12513, 12925, 13300, 13674, 14027, 14352, 14716, 15117, 15477, 15824, 16157, 16513, 16804, 17090, 17401, 17679, 17948, 18238, 18520, 18764, 19078, 19381, 19640, 19921, 20205, 20500, 20813, 21162, 21465, 21794, 22137, 22453, 22756, 23067, 23350, 23636, 23926, 24227, 24521, 24819, 25107, 25414, 25730, 26120, 26497, 26895, 27344, 27877, 28463, 29426, 31355 }; static const int16_t nelly_delta_table[32] = { -11725, -9420, -7910, -6801, -5948, -5233, -4599, -4039, -3507, -3030, -2596, -2170, -1774, -1383, -1016, -660, -329, -1, 337, 696, 1085, 1512, 1962, 2433, 2968, 3569, 4314, 5279, 6622, 8154, 10076, 12975 }; typedef struct NellyMoserDecodeContext { AVCodecContext* avctx; DECLARE_ALIGNED_16(float,float_buf[NELLY_SAMPLES]); float state[64]; AVRandomState random_state; GetBitContext gb; int add_bias; int scale_bias; DSPContext dsp; MDCTContext imdct_ctx; DECLARE_ALIGNED_16(float,imdct_tmp[NELLY_BUF_LEN]); DECLARE_ALIGNED_16(float,imdct_out[NELLY_BUF_LEN * 2]); } NellyMoserDecodeContext; static DECLARE_ALIGNED_16(float,sine_window[128]); static inline int signed_shift(int i, int shift) { if (shift > 0) return i << shift; return i >> -shift; } static void overlap_and_window(NellyMoserDecodeContext *s, float *state, float *audio) { int bot, mid_up, mid_down, top; float s_bot, s_top; bot = 0; top = NELLY_BUF_LEN-1; mid_up = NELLY_BUF_LEN/2; mid_down = (NELLY_BUF_LEN/2)-1; while (bot < NELLY_BUF_LEN/4) { s_bot = audio[bot]; s_top = -audio[top]; audio[bot] = (-audio[mid_up]*sine_window[bot]-state[bot ]*sine_window[top])/s->scale_bias + s->add_bias; audio[top] = (-state[bot ]*sine_window[bot]+audio[mid_up]*sine_window[top])/s->scale_bias + s->add_bias; state[bot] = audio[mid_down]; audio[mid_down] = (s_top *sine_window[mid_down]-state[mid_down]*sine_window[mid_up])/s->scale_bias + s->add_bias; audio[mid_up ] = (-state[mid_down]*sine_window[mid_down]-s_top *sine_window[mid_up])/s->scale_bias + s->add_bias; state[mid_down] = s_bot; bot++; mid_up++; mid_down--; top--; } } static int sum_bits(short *buf, short shift, short off) { int b, i = 0, ret = 0; for (i = 0; i < NELLY_FILL_LEN; i++) { b = buf[i]-off; b = ((b>>(shift-1))+1)>>1; ret += av_clip(b, 0, NELLY_BIT_CAP); } return ret; } static int headroom(int *la) { int l; if (*la == 0) { return 31; } l = 30 - av_log2(FFABS(*la)); *la <<= l; return l; } static void get_sample_bits(const float *buf, int *bits) { int i, j; short sbuf[128]; int bitsum = 0, last_bitsum, small_bitsum, big_bitsum; short shift, shift_saved; int max, sum, last_off, tmp; int big_off, small_off; int off; max = 0; for (i = 0; i < NELLY_FILL_LEN; i++) { max = FFMAX(max, buf[i]); } shift = -16; shift += headroom(&max); sum = 0; for (i = 0; i < NELLY_FILL_LEN; i++) { sbuf[i] = signed_shift(buf[i], shift); sbuf[i] = (3*sbuf[i])>>2; sum += sbuf[i]; } shift += 11; shift_saved = shift; sum -= NELLY_DETAIL_BITS << shift; shift += headroom(&sum); small_off = (NELLY_BASE_OFF * (sum>>16)) >> 15; shift = shift_saved - (NELLY_BASE_SHIFT+shift-31); small_off = signed_shift(small_off, shift); bitsum = sum_bits(sbuf, shift_saved, small_off); if (bitsum != NELLY_DETAIL_BITS) { shift = 0; off = bitsum - NELLY_DETAIL_BITS; for(shift=0; FFABS(off) <= 16383; shift++) off *= 2; off = (off * NELLY_BASE_OFF) >> 15; shift = shift_saved-(NELLY_BASE_SHIFT+shift-15); off = signed_shift(off, shift); for (j = 1; j < 20; j++) { last_off = small_off; small_off += off; last_bitsum = bitsum; bitsum = sum_bits(sbuf, shift_saved, small_off); if ((bitsum-NELLY_DETAIL_BITS) * (last_bitsum-NELLY_DETAIL_BITS) <= 0) break; } if (bitsum > NELLY_DETAIL_BITS) { big_off = small_off; small_off = last_off; big_bitsum=bitsum; small_bitsum=last_bitsum; } else { big_off = last_off; big_bitsum=last_bitsum; small_bitsum=bitsum; } while (bitsum != NELLY_DETAIL_BITS && j <= 19) { off = (big_off+small_off)>>1; bitsum = sum_bits(sbuf, shift_saved, off); if (bitsum > NELLY_DETAIL_BITS) { big_off=off; big_bitsum=bitsum; } else { small_off = off; small_bitsum=bitsum; } j++; } if (abs(big_bitsum-NELLY_DETAIL_BITS) >= abs(small_bitsum-NELLY_DETAIL_BITS)) { bitsum = small_bitsum; } else { small_off = big_off; bitsum = big_bitsum; } } for (i = 0; i < NELLY_FILL_LEN; i++) { tmp = sbuf[i]-small_off; tmp = ((tmp>>(shift_saved-1))+1)>>1; bits[i] = av_clip(tmp, 0, NELLY_BIT_CAP); } if (bitsum > NELLY_DETAIL_BITS) { tmp = i = 0; while (tmp < NELLY_DETAIL_BITS) { tmp += bits[i]; i++; } bits[i-1] -= tmp - NELLY_DETAIL_BITS; for(; i < NELLY_FILL_LEN; i++) bits[i] = 0; } } void nelly_decode_block(NellyMoserDecodeContext *s, const unsigned char block[NELLY_BLOCK_LEN], float audio[NELLY_SAMPLES]) { int i,j; float buf[NELLY_FILL_LEN], pows[NELLY_FILL_LEN]; float *aptr, *bptr, *pptr, val, pval; int bits[NELLY_BUF_LEN]; unsigned char v; init_get_bits(&s->gb, block, NELLY_BLOCK_LEN * 8); bptr = buf; pptr = pows; val = nelly_init_table[get_bits(&s->gb, 6)]; for (i=0 ; i<NELLY_BANDS ; i++) { if (i > 0) val += nelly_delta_table[get_bits(&s->gb, 5)]; pval = pow(2, val/2048); for (j = 0; j < nelly_band_sizes_table[i]; j++) { *bptr++ = val; *pptr++ = pval; } } get_sample_bits(buf, bits); for (i = 0; i < 2; i++) { aptr = audio + i * NELLY_BUF_LEN; init_get_bits(&s->gb, block, NELLY_BLOCK_LEN * 8); skip_bits(&s->gb, NELLY_HEADER_BITS + i*NELLY_DETAIL_BITS); for (j = 0; j < NELLY_FILL_LEN; j++) { if (bits[j] <= 0) { aptr[j] = M_SQRT1_2*pows[j]; if (av_random(&s->random_state) & 1) aptr[j] *= -1.0; } else { v = get_bits(&s->gb, bits[j]); aptr[j] = dequantization_table[(1<<bits[j])-1+v]*pows[j]; } } memset(&aptr[NELLY_FILL_LEN], 0, (NELLY_BUF_LEN - NELLY_FILL_LEN) * sizeof(float)); s->imdct_ctx.fft.imdct_calc(&s->imdct_ctx, s->imdct_out, aptr, s->imdct_tmp); /* XXX: overlapping and windowing should be part of a more generic imdct function */ memcpy(&aptr[0],&s->imdct_out[NELLY_BUF_LEN+NELLY_BUF_LEN/2], (NELLY_BUF_LEN/2)*sizeof(float)); memcpy(&aptr[NELLY_BUF_LEN / 2],&s->imdct_out[0],(NELLY_BUF_LEN/2)*sizeof(float)); overlap_and_window(s, s->state, aptr); } } static int decode_init(AVCodecContext * avctx) { NellyMoserDecodeContext *s = avctx->priv_data; int i; s->avctx = avctx; av_init_random(0, &s->random_state); ff_mdct_init(&s->imdct_ctx, 8, 1); dsputil_init(&s->dsp, avctx); if(s->dsp.float_to_int16 == ff_float_to_int16_c) { s->add_bias = 385; s->scale_bias = 8*32768; } else { s->add_bias = 0; s->scale_bias = 1*8; } /* Generate overlap window */ if (!sine_window[0]) for (i=0 ; i<128; i++) { sine_window[i] = sin((i + 0.5) / 256.0 * M_PI); } return 0; } static int decode_tag(AVCodecContext * avctx, void *data, int *data_size, const uint8_t * buf, int buf_size) { NellyMoserDecodeContext *s = avctx->priv_data; int blocks, i; int16_t* samples; *data_size = 0; samples = (int16_t*)data; if (buf_size < avctx->block_align) return buf_size; switch (buf_size) { case 64: // 8000Hz blocks = 1; break; case 128: // 11025Hz blocks = 2; break; case 256: // 22050Hz blocks = 4; break; case 512: // 44100Hz blocks = 8; break; default: av_log(avctx, AV_LOG_ERROR, "Tag size %d unknown, report sample!\n", buf_size); return buf_size; } for (i=0 ; i<blocks ; i++) { nelly_decode_block(s, &buf[i*NELLY_BLOCK_LEN], s->float_buf); s->dsp.float_to_int16(&samples[i*NELLY_SAMPLES], s->float_buf, NELLY_SAMPLES); *data_size += NELLY_SAMPLES*sizeof(int16_t); } return buf_size; } static int decode_end(AVCodecContext * avctx) { NellyMoserDecodeContext *s = avctx->priv_data; ff_mdct_end(&s->imdct_ctx); return 0; } AVCodec nellymoser_decoder = { "nellymoser", CODEC_TYPE_AUDIO, CODEC_ID_NELLYMOSER, sizeof(NellyMoserDecodeContext), decode_init, NULL, decode_end, decode_tag, };