/* * IMC compatible decoder * Copyright (c) 2002-2004 Maxim Poliakovski * Copyright (c) 2006 Benjamin Larsson * Copyright (c) 2006 Konstantin Shishkov * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** * @file * IMC - Intel Music Coder * A mdct based codec using a 256 points large transform * divided into 32 bands with some mix of scale factors. * Only mono is supported. */ #include <math.h> #include <stddef.h> #include <stdio.h> #include "libavutil/channel_layout.h" #include "libavutil/ffmath.h" #include "libavutil/float_dsp.h" #include "libavutil/internal.h" #include "avcodec.h" #include "bswapdsp.h" #include "get_bits.h" #include "fft.h" #include "internal.h" #include "sinewin.h" #include "imcdata.h" #define IMC_BLOCK_SIZE 64 #define IMC_FRAME_ID 0x21 #define BANDS 32 #define COEFFS 256 typedef struct IMCChannel { float old_floor[BANDS]; float flcoeffs1[BANDS]; float flcoeffs2[BANDS]; float flcoeffs3[BANDS]; float flcoeffs4[BANDS]; float flcoeffs5[BANDS]; float flcoeffs6[BANDS]; float CWdecoded[COEFFS]; int bandWidthT[BANDS]; ///< codewords per band int bitsBandT[BANDS]; ///< how many bits per codeword in band int CWlengthT[COEFFS]; ///< how many bits in each codeword int levlCoeffBuf[BANDS]; int bandFlagsBuf[BANDS]; ///< flags for each band int sumLenArr[BANDS]; ///< bits for all coeffs in band int skipFlagRaw[BANDS]; ///< skip flags are stored in raw form or not int skipFlagBits[BANDS]; ///< bits used to code skip flags int skipFlagCount[BANDS]; ///< skipped coefficients per band int skipFlags[COEFFS]; ///< skip coefficient decoding or not int codewords[COEFFS]; ///< raw codewords read from bitstream float last_fft_im[COEFFS]; int decoder_reset; } IMCChannel; typedef struct IMCContext { IMCChannel chctx[2]; /** MDCT tables */ //@{ float mdct_sine_window[COEFFS]; float post_cos[COEFFS]; float post_sin[COEFFS]; float pre_coef1[COEFFS]; float pre_coef2[COEFFS]; //@} float sqrt_tab[30]; GetBitContext gb; BswapDSPContext bdsp; AVFloatDSPContext *fdsp; FFTContext fft; DECLARE_ALIGNED(32, FFTComplex, samples)[COEFFS / 2]; float *out_samples; int coef0_pos; int8_t cyclTab[32], cyclTab2[32]; float weights1[31], weights2[31]; AVCodecContext *avctx; } IMCContext; static VLC huffman_vlc[4][4]; #define VLC_TABLES_SIZE 9512 static const int vlc_offsets[17] = { 0, 640, 1156, 1732, 2308, 2852, 3396, 3924, 4452, 5220, 5860, 6628, 7268, 7908, 8424, 8936, VLC_TABLES_SIZE }; static VLC_TYPE vlc_tables[VLC_TABLES_SIZE][2]; static inline double freq2bark(double freq) { return 3.5 * atan((freq / 7500.0) * (freq / 7500.0)) + 13.0 * atan(freq * 0.00076); } static av_cold void iac_generate_tabs(IMCContext *q, int sampling_rate) { double freqmin[32], freqmid[32], freqmax[32]; double scale = sampling_rate / (256.0 * 2.0 * 2.0); double nyquist_freq = sampling_rate * 0.5; double freq, bark, prev_bark = 0, tf, tb; int i, j; for (i = 0; i < 32; i++) { freq = (band_tab[i] + band_tab[i + 1] - 1) * scale; bark = freq2bark(freq); if (i > 0) { tb = bark - prev_bark; q->weights1[i - 1] = ff_exp10(-1.0 * tb); q->weights2[i - 1] = ff_exp10(-2.7 * tb); } prev_bark = bark; freqmid[i] = freq; tf = freq; while (tf < nyquist_freq) { tf += 0.5; tb = freq2bark(tf); if (tb > bark + 0.5) break; } freqmax[i] = tf; tf = freq; while (tf > 0.0) { tf -= 0.5; tb = freq2bark(tf); if (tb <= bark - 0.5) break; } freqmin[i] = tf; } for (i = 0; i < 32; i++) { freq = freqmax[i]; for (j = 31; j > 0 && freq <= freqmid[j]; j--); q->cyclTab[i] = j + 1; freq = freqmin[i]; for (j = 0; j < 32 && freq >= freqmid[j]; j++); q->cyclTab2[i] = j - 1; } } static av_cold int imc_decode_init(AVCodecContext *avctx) { int i, j, ret; IMCContext *q = avctx->priv_data; double r1, r2; if (avctx->codec_id == AV_CODEC_ID_IAC && avctx->sample_rate > 96000) { av_log(avctx, AV_LOG_ERROR, "Strange sample rate of %i, file likely corrupt or " "needing a new table derivation method.\n", avctx->sample_rate); return AVERROR_PATCHWELCOME; } if (avctx->codec_id == AV_CODEC_ID_IMC) avctx->channels = 1; if (avctx->channels > 2) { avpriv_request_sample(avctx, "Number of channels > 2"); return AVERROR_PATCHWELCOME; } for (j = 0; j < avctx->channels; j++) { q->chctx[j].decoder_reset = 1; for (i = 0; i < BANDS; i++) q->chctx[j].old_floor[i] = 1.0; for (i = 0; i < COEFFS / 2; i++) q->chctx[j].last_fft_im[i] = 0; } /* Build mdct window, a simple sine window normalized with sqrt(2) */ ff_sine_window_init(q->mdct_sine_window, COEFFS); for (i = 0; i < COEFFS; i++) q->mdct_sine_window[i] *= sqrt(2.0); for (i = 0; i < COEFFS / 2; i++) { q->post_cos[i] = (1.0f / 32768) * cos(i / 256.0 * M_PI); q->post_sin[i] = (1.0f / 32768) * sin(i / 256.0 * M_PI); r1 = sin((i * 4.0 + 1.0) / 1024.0 * M_PI); r2 = cos((i * 4.0 + 1.0) / 1024.0 * M_PI); if (i & 0x1) { q->pre_coef1[i] = (r1 + r2) * sqrt(2.0); q->pre_coef2[i] = -(r1 - r2) * sqrt(2.0); } else { q->pre_coef1[i] = -(r1 + r2) * sqrt(2.0); q->pre_coef2[i] = (r1 - r2) * sqrt(2.0); } } /* Generate a square root table */ for (i = 0; i < 30; i++) q->sqrt_tab[i] = sqrt(i); /* initialize the VLC tables */ for (i = 0; i < 4 ; i++) { for (j = 0; j < 4; j++) { huffman_vlc[i][j].table = &vlc_tables[vlc_offsets[i * 4 + j]]; huffman_vlc[i][j].table_allocated = vlc_offsets[i * 4 + j + 1] - vlc_offsets[i * 4 + j]; init_vlc(&huffman_vlc[i][j], 9, imc_huffman_sizes[i], imc_huffman_lens[i][j], 1, 1, imc_huffman_bits[i][j], 2, 2, INIT_VLC_USE_NEW_STATIC); } } if (avctx->codec_id == AV_CODEC_ID_IAC) { iac_generate_tabs(q, avctx->sample_rate); } else { memcpy(q->cyclTab, cyclTab, sizeof(cyclTab)); memcpy(q->cyclTab2, cyclTab2, sizeof(cyclTab2)); memcpy(q->weights1, imc_weights1, sizeof(imc_weights1)); memcpy(q->weights2, imc_weights2, sizeof(imc_weights2)); } if ((ret = ff_fft_init(&q->fft, 7, 1))) { av_log(avctx, AV_LOG_INFO, "FFT init failed\n"); return ret; } ff_bswapdsp_init(&q->bdsp); q->fdsp = avpriv_float_dsp_alloc(avctx->flags & AV_CODEC_FLAG_BITEXACT); if (!q->fdsp) { ff_fft_end(&q->fft); return AVERROR(ENOMEM); } avctx->sample_fmt = AV_SAMPLE_FMT_FLTP; avctx->channel_layout = avctx->channels == 1 ? AV_CH_LAYOUT_MONO : AV_CH_LAYOUT_STEREO; return 0; } static void imc_calculate_coeffs(IMCContext *q, float *flcoeffs1, float *flcoeffs2, int *bandWidthT, float *flcoeffs3, float *flcoeffs5) { float workT1[BANDS]; float workT2[BANDS]; float workT3[BANDS]; float snr_limit = 1.e-30; float accum = 0.0; int i, cnt2; for (i = 0; i < BANDS; i++) { flcoeffs5[i] = workT2[i] = 0.0; if (bandWidthT[i]) { workT1[i] = flcoeffs1[i] * flcoeffs1[i]; flcoeffs3[i] = 2.0 * flcoeffs2[i]; } else { workT1[i] = 0.0; flcoeffs3[i] = -30000.0; } workT3[i] = bandWidthT[i] * workT1[i] * 0.01; if (workT3[i] <= snr_limit) workT3[i] = 0.0; } for (i = 0; i < BANDS; i++) { for (cnt2 = i; cnt2 < q->cyclTab[i]; cnt2++) flcoeffs5[cnt2] = flcoeffs5[cnt2] + workT3[i]; workT2[cnt2 - 1] = workT2[cnt2 - 1] + workT3[i]; } for (i = 1; i < BANDS; i++) { accum = (workT2[i - 1] + accum) * q->weights1[i - 1]; flcoeffs5[i] += accum; } for (i = 0; i < BANDS; i++) workT2[i] = 0.0; for (i = 0; i < BANDS; i++) { for (cnt2 = i - 1; cnt2 > q->cyclTab2[i]; cnt2--) flcoeffs5[cnt2] += workT3[i]; workT2[cnt2+1] += workT3[i]; } accum = 0.0; for (i = BANDS-2; i >= 0; i--) { accum = (workT2[i+1] + accum) * q->weights2[i]; flcoeffs5[i] += accum; // there is missing code here, but it seems to never be triggered } } static void imc_read_level_coeffs(IMCContext *q, int stream_format_code, int *levlCoeffs) { int i; VLC *hufftab[4]; int start = 0; const uint8_t *cb_sel; int s; s = stream_format_code >> 1; hufftab[0] = &huffman_vlc[s][0]; hufftab[1] = &huffman_vlc[s][1]; hufftab[2] = &huffman_vlc[s][2]; hufftab[3] = &huffman_vlc[s][3]; cb_sel = imc_cb_select[s]; if (stream_format_code & 4) start = 1; if (start) levlCoeffs[0] = get_bits(&q->gb, 7); for (i = start; i < BANDS; i++) { levlCoeffs[i] = get_vlc2(&q->gb, hufftab[cb_sel[i]]->table, hufftab[cb_sel[i]]->bits, 2); if (levlCoeffs[i] == 17) levlCoeffs[i] += get_bits(&q->gb, 4); } } static void imc_read_level_coeffs_raw(IMCContext *q, int stream_format_code, int *levlCoeffs) { int i; q->coef0_pos = get_bits(&q->gb, 5); levlCoeffs[0] = get_bits(&q->gb, 7); for (i = 1; i < BANDS; i++) levlCoeffs[i] = get_bits(&q->gb, 4); } static void imc_decode_level_coefficients(IMCContext *q, int *levlCoeffBuf, float *flcoeffs1, float *flcoeffs2) { int i, level; float tmp, tmp2; // maybe some frequency division thingy flcoeffs1[0] = 20000.0 / exp2 (levlCoeffBuf[0] * 0.18945); // 0.18945 = log2(10) * 0.05703125 flcoeffs2[0] = log2f(flcoeffs1[0]); tmp = flcoeffs1[0]; tmp2 = flcoeffs2[0]; for (i = 1; i < BANDS; i++) { level = levlCoeffBuf[i]; if (level == 16) { flcoeffs1[i] = 1.0; flcoeffs2[i] = 0.0; } else { if (level < 17) level -= 7; else if (level <= 24) level -= 32; else level -= 16; tmp *= imc_exp_tab[15 + level]; tmp2 += 0.83048 * level; // 0.83048 = log2(10) * 0.25 flcoeffs1[i] = tmp; flcoeffs2[i] = tmp2; } } } static void imc_decode_level_coefficients2(IMCContext *q, int *levlCoeffBuf, float *old_floor, float *flcoeffs1, float *flcoeffs2) { int i; /* FIXME maybe flag_buf = noise coding and flcoeffs1 = new scale factors * and flcoeffs2 old scale factors * might be incomplete due to a missing table that is in the binary code */ for (i = 0; i < BANDS; i++) { flcoeffs1[i] = 0; if (levlCoeffBuf[i] < 16) { flcoeffs1[i] = imc_exp_tab2[levlCoeffBuf[i]] * old_floor[i]; flcoeffs2[i] = (levlCoeffBuf[i] - 7) * 0.83048 + flcoeffs2[i]; // 0.83048 = log2(10) * 0.25 } else { flcoeffs1[i] = old_floor[i]; } } } static void imc_decode_level_coefficients_raw(IMCContext *q, int *levlCoeffBuf, float *flcoeffs1, float *flcoeffs2) { int i, level, pos; float tmp, tmp2; pos = q->coef0_pos; flcoeffs1[pos] = 20000.0 / pow (2, levlCoeffBuf[0] * 0.18945); // 0.18945 = log2(10) * 0.05703125 flcoeffs2[pos] = log2f(flcoeffs1[pos]); tmp = flcoeffs1[pos]; tmp2 = flcoeffs2[pos]; levlCoeffBuf++; for (i = 0; i < BANDS; i++) { if (i == pos) continue; level = *levlCoeffBuf++; flcoeffs1[i] = tmp * powf(10.0, -level * 0.4375); //todo tab flcoeffs2[i] = tmp2 - 1.4533435415 * level; // 1.4533435415 = log2(10) * 0.4375 } } /** * Perform bit allocation depending on bits available */ static int bit_allocation(IMCContext *q, IMCChannel *chctx, int stream_format_code, int freebits, int flag) { int i, j; const float limit = -1.e20; float highest = 0.0; int indx; int t1 = 0; int t2 = 1; float summa = 0.0; int iacc = 0; int summer = 0; int rres, cwlen; float lowest = 1.e10; int low_indx = 0; float workT[32]; int flg; int found_indx = 0; for (i = 0; i < BANDS; i++) highest = FFMAX(highest, chctx->flcoeffs1[i]); for (i = 0; i < BANDS - 1; i++) { if (chctx->flcoeffs5[i] <= 0) { av_log(q->avctx, AV_LOG_ERROR, "flcoeffs5 %f invalid\n", chctx->flcoeffs5[i]); return AVERROR_INVALIDDATA; } chctx->flcoeffs4[i] = chctx->flcoeffs3[i] - log2f(chctx->flcoeffs5[i]); } chctx->flcoeffs4[BANDS - 1] = limit; highest = highest * 0.25; for (i = 0; i < BANDS; i++) { indx = -1; if ((band_tab[i + 1] - band_tab[i]) == chctx->bandWidthT[i]) indx = 0; if ((band_tab[i + 1] - band_tab[i]) > chctx->bandWidthT[i]) indx = 1; if (((band_tab[i + 1] - band_tab[i]) / 2) >= chctx->bandWidthT[i]) indx = 2; if (indx == -1) return AVERROR_INVALIDDATA; chctx->flcoeffs4[i] += xTab[(indx * 2 + (chctx->flcoeffs1[i] < highest)) * 2 + flag]; } if (stream_format_code & 0x2) { chctx->flcoeffs4[0] = limit; chctx->flcoeffs4[1] = limit; chctx->flcoeffs4[2] = limit; chctx->flcoeffs4[3] = limit; } for (i = (stream_format_code & 0x2) ? 4 : 0; i < BANDS - 1; i++) { iacc += chctx->bandWidthT[i]; summa += chctx->bandWidthT[i] * chctx->flcoeffs4[i]; } if (!iacc) return AVERROR_INVALIDDATA; chctx->bandWidthT[BANDS - 1] = 0; summa = (summa * 0.5 - freebits) / iacc; for (i = 0; i < BANDS / 2; i++) { rres = summer - freebits; if ((rres >= -8) && (rres <= 8)) break; summer = 0; iacc = 0; for (j = (stream_format_code & 0x2) ? 4 : 0; j < BANDS; j++) { cwlen = av_clipf(((chctx->flcoeffs4[j] * 0.5) - summa + 0.5), 0, 6); chctx->bitsBandT[j] = cwlen; summer += chctx->bandWidthT[j] * cwlen; if (cwlen > 0) iacc += chctx->bandWidthT[j]; } flg = t2; t2 = 1; if (freebits < summer) t2 = -1; if (i == 0) flg = t2; if (flg != t2) t1++; summa = (float)(summer - freebits) / ((t1 + 1) * iacc) + summa; } for (i = (stream_format_code & 0x2) ? 4 : 0; i < BANDS; i++) { for (j = band_tab[i]; j < band_tab[i + 1]; j++) chctx->CWlengthT[j] = chctx->bitsBandT[i]; } if (freebits > summer) { for (i = 0; i < BANDS; i++) { workT[i] = (chctx->bitsBandT[i] == 6) ? -1.e20 : (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] - 0.415); } highest = 0.0; do { if (highest <= -1.e20) break; found_indx = 0; highest = -1.e20; for (i = 0; i < BANDS; i++) { if (workT[i] > highest) { highest = workT[i]; found_indx = i; } } if (highest > -1.e20) { workT[found_indx] -= 2.0; if (++chctx->bitsBandT[found_indx] == 6) workT[found_indx] = -1.e20; for (j = band_tab[found_indx]; j < band_tab[found_indx + 1] && (freebits > summer); j++) { chctx->CWlengthT[j]++; summer++; } } } while (freebits > summer); } if (freebits < summer) { for (i = 0; i < BANDS; i++) { workT[i] = chctx->bitsBandT[i] ? (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] + 1.585) : 1.e20; } if (stream_format_code & 0x2) { workT[0] = 1.e20; workT[1] = 1.e20; workT[2] = 1.e20; workT[3] = 1.e20; } while (freebits < summer) { lowest = 1.e10; low_indx = 0; for (i = 0; i < BANDS; i++) { if (workT[i] < lowest) { lowest = workT[i]; low_indx = i; } } // if (lowest >= 1.e10) // break; workT[low_indx] = lowest + 2.0; if (!--chctx->bitsBandT[low_indx]) workT[low_indx] = 1.e20; for (j = band_tab[low_indx]; j < band_tab[low_indx+1] && (freebits < summer); j++) { if (chctx->CWlengthT[j] > 0) { chctx->CWlengthT[j]--; summer--; } } } } return 0; } static void imc_get_skip_coeff(IMCContext *q, IMCChannel *chctx) { int i, j; memset(chctx->skipFlagBits, 0, sizeof(chctx->skipFlagBits)); memset(chctx->skipFlagCount, 0, sizeof(chctx->skipFlagCount)); for (i = 0; i < BANDS; i++) { if (!chctx->bandFlagsBuf[i] || !chctx->bandWidthT[i]) continue; if (!chctx->skipFlagRaw[i]) { chctx->skipFlagBits[i] = band_tab[i + 1] - band_tab[i]; for (j = band_tab[i]; j < band_tab[i + 1]; j++) { chctx->skipFlags[j] = get_bits1(&q->gb); if (chctx->skipFlags[j]) chctx->skipFlagCount[i]++; } } else { for (j = band_tab[i]; j < band_tab[i + 1] - 1; j += 2) { if (!get_bits1(&q->gb)) { // 0 chctx->skipFlagBits[i]++; chctx->skipFlags[j] = 1; chctx->skipFlags[j + 1] = 1; chctx->skipFlagCount[i] += 2; } else { if (get_bits1(&q->gb)) { // 11 chctx->skipFlagBits[i] += 2; chctx->skipFlags[j] = 0; chctx->skipFlags[j + 1] = 1; chctx->skipFlagCount[i]++; } else { chctx->skipFlagBits[i] += 3; chctx->skipFlags[j + 1] = 0; if (!get_bits1(&q->gb)) { // 100 chctx->skipFlags[j] = 1; chctx->skipFlagCount[i]++; } else { // 101 chctx->skipFlags[j] = 0; } } } } if (j < band_tab[i + 1]) { chctx->skipFlagBits[i]++; if ((chctx->skipFlags[j] = get_bits1(&q->gb))) chctx->skipFlagCount[i]++; } } } } /** * Increase highest' band coefficient sizes as some bits won't be used */ static void imc_adjust_bit_allocation(IMCContext *q, IMCChannel *chctx, int summer) { float workT[32]; int corrected = 0; int i, j; float highest = 0; int found_indx = 0; for (i = 0; i < BANDS; i++) { workT[i] = (chctx->bitsBandT[i] == 6) ? -1.e20 : (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] - 0.415); } while (corrected < summer) { if (highest <= -1.e20) break; highest = -1.e20; for (i = 0; i < BANDS; i++) { if (workT[i] > highest) { highest = workT[i]; found_indx = i; } } if (highest > -1.e20) { workT[found_indx] -= 2.0; if (++(chctx->bitsBandT[found_indx]) == 6) workT[found_indx] = -1.e20; for (j = band_tab[found_indx]; j < band_tab[found_indx+1] && (corrected < summer); j++) { if (!chctx->skipFlags[j] && (chctx->CWlengthT[j] < 6)) { chctx->CWlengthT[j]++; corrected++; } } } } } static void imc_imdct256(IMCContext *q, IMCChannel *chctx, int channels) { int i; float re, im; float *dst1 = q->out_samples; float *dst2 = q->out_samples + (COEFFS - 1); /* prerotation */ for (i = 0; i < COEFFS / 2; i++) { q->samples[i].re = -(q->pre_coef1[i] * chctx->CWdecoded[COEFFS - 1 - i * 2]) - (q->pre_coef2[i] * chctx->CWdecoded[i * 2]); q->samples[i].im = (q->pre_coef2[i] * chctx->CWdecoded[COEFFS - 1 - i * 2]) - (q->pre_coef1[i] * chctx->CWdecoded[i * 2]); } /* FFT */ q->fft.fft_permute(&q->fft, q->samples); q->fft.fft_calc(&q->fft, q->samples); /* postrotation, window and reorder */ for (i = 0; i < COEFFS / 2; i++) { re = ( q->samples[i].re * q->post_cos[i]) + (-q->samples[i].im * q->post_sin[i]); im = (-q->samples[i].im * q->post_cos[i]) - ( q->samples[i].re * q->post_sin[i]); *dst1 = (q->mdct_sine_window[COEFFS - 1 - i * 2] * chctx->last_fft_im[i]) + (q->mdct_sine_window[i * 2] * re); *dst2 = (q->mdct_sine_window[i * 2] * chctx->last_fft_im[i]) - (q->mdct_sine_window[COEFFS - 1 - i * 2] * re); dst1 += 2; dst2 -= 2; chctx->last_fft_im[i] = im; } } static int inverse_quant_coeff(IMCContext *q, IMCChannel *chctx, int stream_format_code) { int i, j; int middle_value, cw_len, max_size; const float *quantizer; for (i = 0; i < BANDS; i++) { for (j = band_tab[i]; j < band_tab[i + 1]; j++) { chctx->CWdecoded[j] = 0; cw_len = chctx->CWlengthT[j]; if (cw_len <= 0 || chctx->skipFlags[j]) continue; max_size = 1 << cw_len; middle_value = max_size >> 1; if (chctx->codewords[j] >= max_size || chctx->codewords[j] < 0) return AVERROR_INVALIDDATA; if (cw_len >= 4) { quantizer = imc_quantizer2[(stream_format_code & 2) >> 1]; if (chctx->codewords[j] >= middle_value) chctx->CWdecoded[j] = quantizer[chctx->codewords[j] - 8] * chctx->flcoeffs6[i]; else chctx->CWdecoded[j] = -quantizer[max_size - chctx->codewords[j] - 8 - 1] * chctx->flcoeffs6[i]; }else{ quantizer = imc_quantizer1[((stream_format_code & 2) >> 1) | (chctx->bandFlagsBuf[i] << 1)]; if (chctx->codewords[j] >= middle_value) chctx->CWdecoded[j] = quantizer[chctx->codewords[j] - 1] * chctx->flcoeffs6[i]; else chctx->CWdecoded[j] = -quantizer[max_size - 2 - chctx->codewords[j]] * chctx->flcoeffs6[i]; } } } return 0; } static void imc_get_coeffs(AVCodecContext *avctx, IMCContext *q, IMCChannel *chctx) { int i, j, cw_len, cw; for (i = 0; i < BANDS; i++) { if (!chctx->sumLenArr[i]) continue; if (chctx->bandFlagsBuf[i] || chctx->bandWidthT[i]) { for (j = band_tab[i]; j < band_tab[i + 1]; j++) { cw_len = chctx->CWlengthT[j]; cw = 0; if (cw_len && (!chctx->bandFlagsBuf[i] || !chctx->skipFlags[j])) { if (get_bits_count(&q->gb) + cw_len > 512) { av_log(avctx, AV_LOG_WARNING, "Potential problem on band %i, coefficient %i" ": cw_len=%i\n", i, j, cw_len); } else cw = get_bits(&q->gb, cw_len); } chctx->codewords[j] = cw; } } } } static void imc_refine_bit_allocation(IMCContext *q, IMCChannel *chctx) { int i, j; int bits, summer; for (i = 0; i < BANDS; i++) { chctx->sumLenArr[i] = 0; chctx->skipFlagRaw[i] = 0; for (j = band_tab[i]; j < band_tab[i + 1]; j++) chctx->sumLenArr[i] += chctx->CWlengthT[j]; if (chctx->bandFlagsBuf[i]) if (((int)((band_tab[i + 1] - band_tab[i]) * 1.5) > chctx->sumLenArr[i]) && (chctx->sumLenArr[i] > 0)) chctx->skipFlagRaw[i] = 1; } imc_get_skip_coeff(q, chctx); for (i = 0; i < BANDS; i++) { chctx->flcoeffs6[i] = chctx->flcoeffs1[i]; /* band has flag set and at least one coded coefficient */ if (chctx->bandFlagsBuf[i] && (band_tab[i + 1] - band_tab[i]) != chctx->skipFlagCount[i]) { chctx->flcoeffs6[i] *= q->sqrt_tab[ band_tab[i + 1] - band_tab[i]] / q->sqrt_tab[(band_tab[i + 1] - band_tab[i] - chctx->skipFlagCount[i])]; } } /* calculate bits left, bits needed and adjust bit allocation */ bits = summer = 0; for (i = 0; i < BANDS; i++) { if (chctx->bandFlagsBuf[i]) { for (j = band_tab[i]; j < band_tab[i + 1]; j++) { if (chctx->skipFlags[j]) { summer += chctx->CWlengthT[j]; chctx->CWlengthT[j] = 0; } } bits += chctx->skipFlagBits[i]; summer -= chctx->skipFlagBits[i]; } } imc_adjust_bit_allocation(q, chctx, summer); } static int imc_decode_block(AVCodecContext *avctx, IMCContext *q, int ch) { int stream_format_code; int imc_hdr, i, j, ret; int flag; int bits; int counter, bitscount; IMCChannel *chctx = q->chctx + ch; /* Check the frame header */ imc_hdr = get_bits(&q->gb, 9); if (imc_hdr & 0x18) { av_log(avctx, AV_LOG_ERROR, "frame header check failed!\n"); av_log(avctx, AV_LOG_ERROR, "got %X.\n", imc_hdr); return AVERROR_INVALIDDATA; } stream_format_code = get_bits(&q->gb, 3); if (stream_format_code & 0x04) chctx->decoder_reset = 1; if (chctx->decoder_reset) { for (i = 0; i < BANDS; i++) chctx->old_floor[i] = 1.0; for (i = 0; i < COEFFS; i++) chctx->CWdecoded[i] = 0; chctx->decoder_reset = 0; } flag = get_bits1(&q->gb); if (stream_format_code & 0x1) imc_read_level_coeffs_raw(q, stream_format_code, chctx->levlCoeffBuf); else imc_read_level_coeffs(q, stream_format_code, chctx->levlCoeffBuf); if (stream_format_code & 0x1) imc_decode_level_coefficients_raw(q, chctx->levlCoeffBuf, chctx->flcoeffs1, chctx->flcoeffs2); else if (stream_format_code & 0x4) imc_decode_level_coefficients(q, chctx->levlCoeffBuf, chctx->flcoeffs1, chctx->flcoeffs2); else imc_decode_level_coefficients2(q, chctx->levlCoeffBuf, chctx->old_floor, chctx->flcoeffs1, chctx->flcoeffs2); for(i=0; i<BANDS; i++) { if(chctx->flcoeffs1[i] > INT_MAX) { av_log(avctx, AV_LOG_ERROR, "scalefactor out of range\n"); return AVERROR_INVALIDDATA; } } memcpy(chctx->old_floor, chctx->flcoeffs1, 32 * sizeof(float)); counter = 0; if (stream_format_code & 0x1) { for (i = 0; i < BANDS; i++) { chctx->bandWidthT[i] = band_tab[i + 1] - band_tab[i]; chctx->bandFlagsBuf[i] = 0; chctx->flcoeffs3[i] = chctx->flcoeffs2[i] * 2; chctx->flcoeffs5[i] = 1.0; } } else { for (i = 0; i < BANDS; i++) { if (chctx->levlCoeffBuf[i] == 16) { chctx->bandWidthT[i] = 0; counter++; } else chctx->bandWidthT[i] = band_tab[i + 1] - band_tab[i]; } memset(chctx->bandFlagsBuf, 0, BANDS * sizeof(int)); for (i = 0; i < BANDS - 1; i++) if (chctx->bandWidthT[i]) chctx->bandFlagsBuf[i] = get_bits1(&q->gb); imc_calculate_coeffs(q, chctx->flcoeffs1, chctx->flcoeffs2, chctx->bandWidthT, chctx->flcoeffs3, chctx->flcoeffs5); } bitscount = 0; /* first 4 bands will be assigned 5 bits per coefficient */ if (stream_format_code & 0x2) { bitscount += 15; chctx->bitsBandT[0] = 5; chctx->CWlengthT[0] = 5; chctx->CWlengthT[1] = 5; chctx->CWlengthT[2] = 5; for (i = 1; i < 4; i++) { if (stream_format_code & 0x1) bits = 5; else bits = (chctx->levlCoeffBuf[i] == 16) ? 0 : 5; chctx->bitsBandT[i] = bits; for (j = band_tab[i]; j < band_tab[i + 1]; j++) { chctx->CWlengthT[j] = bits; bitscount += bits; } } } if (avctx->codec_id == AV_CODEC_ID_IAC) { bitscount += !!chctx->bandWidthT[BANDS - 1]; if (!(stream_format_code & 0x2)) bitscount += 16; } if ((ret = bit_allocation(q, chctx, stream_format_code, 512 - bitscount - get_bits_count(&q->gb), flag)) < 0) { av_log(avctx, AV_LOG_ERROR, "Bit allocations failed\n"); chctx->decoder_reset = 1; return ret; } if (stream_format_code & 0x1) { for (i = 0; i < BANDS; i++) chctx->skipFlags[i] = 0; } else { imc_refine_bit_allocation(q, chctx); } for (i = 0; i < BANDS; i++) { chctx->sumLenArr[i] = 0; for (j = band_tab[i]; j < band_tab[i + 1]; j++) if (!chctx->skipFlags[j]) chctx->sumLenArr[i] += chctx->CWlengthT[j]; } memset(chctx->codewords, 0, sizeof(chctx->codewords)); imc_get_coeffs(avctx, q, chctx); if (inverse_quant_coeff(q, chctx, stream_format_code) < 0) { av_log(avctx, AV_LOG_ERROR, "Inverse quantization of coefficients failed\n"); chctx->decoder_reset = 1; return AVERROR_INVALIDDATA; } memset(chctx->skipFlags, 0, sizeof(chctx->skipFlags)); imc_imdct256(q, chctx, avctx->channels); return 0; } static int imc_decode_frame(AVCodecContext *avctx, void *data, int *got_frame_ptr, AVPacket *avpkt) { AVFrame *frame = data; const uint8_t *buf = avpkt->data; int buf_size = avpkt->size; int ret, i; IMCContext *q = avctx->priv_data; LOCAL_ALIGNED_16(uint16_t, buf16, [(IMC_BLOCK_SIZE + AV_INPUT_BUFFER_PADDING_SIZE) / 2]); q->avctx = avctx; if (buf_size < IMC_BLOCK_SIZE * avctx->channels) { av_log(avctx, AV_LOG_ERROR, "frame too small!\n"); return AVERROR_INVALIDDATA; } /* get output buffer */ frame->nb_samples = COEFFS; if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) return ret; for (i = 0; i < avctx->channels; i++) { q->out_samples = (float *)frame->extended_data[i]; q->bdsp.bswap16_buf(buf16, (const uint16_t *) buf, IMC_BLOCK_SIZE / 2); init_get_bits(&q->gb, (const uint8_t*)buf16, IMC_BLOCK_SIZE * 8); buf += IMC_BLOCK_SIZE; if ((ret = imc_decode_block(avctx, q, i)) < 0) return ret; } if (avctx->channels == 2) { q->fdsp->butterflies_float((float *)frame->extended_data[0], (float *)frame->extended_data[1], COEFFS); } *got_frame_ptr = 1; return IMC_BLOCK_SIZE * avctx->channels; } static av_cold int imc_decode_close(AVCodecContext * avctx) { IMCContext *q = avctx->priv_data; ff_fft_end(&q->fft); av_freep(&q->fdsp); return 0; } static av_cold void flush(AVCodecContext *avctx) { IMCContext *q = avctx->priv_data; q->chctx[0].decoder_reset = q->chctx[1].decoder_reset = 1; } #if CONFIG_IMC_DECODER AVCodec ff_imc_decoder = { .name = "imc", .long_name = NULL_IF_CONFIG_SMALL("IMC (Intel Music Coder)"), .type = AVMEDIA_TYPE_AUDIO, .id = AV_CODEC_ID_IMC, .priv_data_size = sizeof(IMCContext), .init = imc_decode_init, .close = imc_decode_close, .decode = imc_decode_frame, .flush = flush, .capabilities = AV_CODEC_CAP_DR1, .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP, AV_SAMPLE_FMT_NONE }, }; #endif #if CONFIG_IAC_DECODER AVCodec ff_iac_decoder = { .name = "iac", .long_name = NULL_IF_CONFIG_SMALL("IAC (Indeo Audio Coder)"), .type = AVMEDIA_TYPE_AUDIO, .id = AV_CODEC_ID_IAC, .priv_data_size = sizeof(IMCContext), .init = imc_decode_init, .close = imc_decode_close, .decode = imc_decode_frame, .flush = flush, .capabilities = AV_CODEC_CAP_DR1, .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP, AV_SAMPLE_FMT_NONE }, }; #endif