| /* |
| * 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/float_dsp.h" |
| #include "libavutil/internal.h" |
| #include "libavutil/libm.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 coeffients 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]; |
| } 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(NULL, 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 ((((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]); |
| |
| 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 |
