/* * 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 * 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 "nellymoser.h" #include "libavutil/lfg.h" #include "libavutil/random_seed.h" #include "avcodec.h" #include "dsputil.h" #include "fft.h" #define ALT_BITSTREAM_READER_LE #include "get_bits.h" typedef struct NellyMoserDecodeContext { AVCodecContext* avctx; DECLARE_ALIGNED(16, float,float_buf)[NELLY_SAMPLES]; float state[128]; AVLFG random_state; GetBitContext gb; int add_bias; float scale_bias; DSPContext dsp; FFTContext imdct_ctx; DECLARE_ALIGNED(16, float,imdct_out)[NELLY_BUF_LEN * 2]; } NellyMoserDecodeContext; static void overlap_and_window(NellyMoserDecodeContext *s, float *state, float *audio, float *a_in) { int bot, top; bot = 0; top = NELLY_BUF_LEN-1; while (bot < NELLY_BUF_LEN) { audio[bot] = a_in [bot]*ff_sine_128[bot] +state[bot]*ff_sine_128[top] + s->add_bias; bot++; top--; } memcpy(state, a_in + NELLY_BUF_LEN, sizeof(float)*NELLY_BUF_LEN); } static 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 = ff_nelly_init_table[get_bits(&s->gb, 6)]; for (i=0 ; i<NELLY_BANDS ; i++) { if (i > 0) val += ff_nelly_delta_table[get_bits(&s->gb, 5)]; pval = -pow(2, val/2048) * s->scale_bias; for (j = 0; j < ff_nelly_band_sizes_table[i]; j++) { *bptr++ = val; *pptr++ = pval; } } ff_nelly_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_long(&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_lfg_get(&s->random_state) & 1) aptr[j] *= -1.0; } else { v = get_bits(&s->gb, bits[j]); aptr[j] = ff_nelly_dequantization_table[(1<<bits[j])-1+v]*pows[j]; } } memset(&aptr[NELLY_FILL_LEN], 0, (NELLY_BUF_LEN - NELLY_FILL_LEN) * sizeof(float)); ff_imdct_calc(&s->imdct_ctx, s->imdct_out, aptr); /* XXX: overlapping and windowing should be part of a more generic imdct function */ overlap_and_window(s, s->state, aptr, s->imdct_out); } } static av_cold int decode_init(AVCodecContext * avctx) { NellyMoserDecodeContext *s = avctx->priv_data; s->avctx = avctx; av_lfg_init(&s->random_state, 0); ff_mdct_init(&s->imdct_ctx, 8, 1, 1.0); dsputil_init(&s->dsp, avctx); if(s->dsp.float_to_int16 == ff_float_to_int16_c) { s->add_bias = 385; s->scale_bias = 1.0/(8*32768); } else { s->add_bias = 0; s->scale_bias = 1.0/(1*8); } /* Generate overlap window */ if (!ff_sine_128[127]) ff_init_ff_sine_windows(7); avctx->sample_fmt = SAMPLE_FMT_S16; avctx->channel_layout = CH_LAYOUT_MONO; return 0; } static int decode_tag(AVCodecContext * avctx, void *data, int *data_size, AVPacket *avpkt) { const uint8_t *buf = avpkt->data; int buf_size = avpkt->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 192: // 16000Hz blocks = 3; break; case 256: // 22050Hz blocks = 4; break; case 512: // 44100Hz blocks = 8; break; default: av_log(avctx, AV_LOG_DEBUG, "Tag size %d.\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 av_cold int decode_end(AVCodecContext * avctx) { NellyMoserDecodeContext *s = avctx->priv_data; ff_mdct_end(&s->imdct_ctx); return 0; } AVCodec nellymoser_decoder = { "nellymoser", AVMEDIA_TYPE_AUDIO, CODEC_ID_NELLYMOSER, sizeof(NellyMoserDecodeContext), decode_init, NULL, decode_end, decode_tag, .long_name = NULL_IF_CONFIG_SMALL("Nellymoser Asao"), };