| Line | Branch | Exec | Source |
|---|---|---|---|
| 1 | /* | ||
| 2 | * MOFLEX Fast Audio decoder | ||
| 3 | * Copyright (c) 2015-2016 Florian Nouwt | ||
| 4 | * Copyright (c) 2017 Adib Surani | ||
| 5 | * Copyright (c) 2020 Paul B Mahol | ||
| 6 | * | ||
| 7 | * This file is part of FFmpeg. | ||
| 8 | * | ||
| 9 | * FFmpeg is free software; you can redistribute it and/or | ||
| 10 | * modify it under the terms of the GNU Lesser General Public | ||
| 11 | * License as published by the Free Software Foundation; either | ||
| 12 | * version 2.1 of the License, or (at your option) any later version. | ||
| 13 | * | ||
| 14 | * FFmpeg is distributed in the hope that it will be useful, | ||
| 15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
| 16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | ||
| 17 | * Lesser General Public License for more details. | ||
| 18 | * | ||
| 19 | * You should have received a copy of the GNU Lesser General Public | ||
| 20 | * License along with FFmpeg; if not, write to the Free Software | ||
| 21 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | ||
| 22 | */ | ||
| 23 | |||
| 24 | #include "libavutil/mem.h" | ||
| 25 | #include "avcodec.h" | ||
| 26 | #include "bytestream.h" | ||
| 27 | #include "codec_internal.h" | ||
| 28 | #include "decode.h" | ||
| 29 | |||
| 30 | typedef struct ChannelItems { | ||
| 31 | float f[8]; | ||
| 32 | float last; | ||
| 33 | } ChannelItems; | ||
| 34 | |||
| 35 | typedef struct FastAudioContext { | ||
| 36 | float table[8][64]; | ||
| 37 | |||
| 38 | ChannelItems *ch; | ||
| 39 | } FastAudioContext; | ||
| 40 | |||
| 41 | ✗ | static av_cold int fastaudio_init(AVCodecContext *avctx) | |
| 42 | { | ||
| 43 | ✗ | FastAudioContext *s = avctx->priv_data; | |
| 44 | |||
| 45 | ✗ | avctx->sample_fmt = AV_SAMPLE_FMT_FLTP; | |
| 46 | |||
| 47 | ✗ | for (int i = 0; i < 8; i++) | |
| 48 | ✗ | s->table[0][i] = (i - 159.5f) / 160.f; | |
| 49 | ✗ | for (int i = 0; i < 11; i++) | |
| 50 | ✗ | s->table[0][i + 8] = (i - 37.5f) / 40.f; | |
| 51 | ✗ | for (int i = 0; i < 27; i++) | |
| 52 | ✗ | s->table[0][i + 8 + 11] = (i - 13.f) / 20.f; | |
| 53 | ✗ | for (int i = 0; i < 11; i++) | |
| 54 | ✗ | s->table[0][i + 8 + 11 + 27] = (i + 27.5f) / 40.f; | |
| 55 | ✗ | for (int i = 0; i < 7; i++) | |
| 56 | ✗ | s->table[0][i + 8 + 11 + 27 + 11] = (i + 152.5f) / 160.f; | |
| 57 | |||
| 58 | ✗ | memcpy(s->table[1], s->table[0], sizeof(s->table[0])); | |
| 59 | |||
| 60 | ✗ | for (int i = 0; i < 7; i++) | |
| 61 | ✗ | s->table[2][i] = (i - 33.5f) / 40.f; | |
| 62 | ✗ | for (int i = 0; i < 25; i++) | |
| 63 | ✗ | s->table[2][i + 7] = (i - 13.f) / 20.f; | |
| 64 | |||
| 65 | ✗ | for (int i = 0; i < 32; i++) | |
| 66 | ✗ | s->table[3][i] = -s->table[2][31 - i]; | |
| 67 | |||
| 68 | ✗ | for (int i = 0; i < 16; i++) | |
| 69 | ✗ | s->table[4][i] = i * 0.22f / 3.f - 0.6f; | |
| 70 | |||
| 71 | ✗ | for (int i = 0; i < 16; i++) | |
| 72 | ✗ | s->table[5][i] = i * 0.20f / 3.f - 0.3f; | |
| 73 | |||
| 74 | ✗ | for (int i = 0; i < 8; i++) | |
| 75 | ✗ | s->table[6][i] = i * 0.36f / 3.f - 0.4f; | |
| 76 | |||
| 77 | ✗ | for (int i = 0; i < 8; i++) | |
| 78 | ✗ | s->table[7][i] = i * 0.34f / 3.f - 0.2f; | |
| 79 | |||
| 80 | ✗ | s->ch = av_calloc(avctx->ch_layout.nb_channels, sizeof(*s->ch)); | |
| 81 | ✗ | if (!s->ch) | |
| 82 | ✗ | return AVERROR(ENOMEM); | |
| 83 | |||
| 84 | ✗ | return 0; | |
| 85 | } | ||
| 86 | |||
| 87 | ✗ | static int read_bits(int bits, int *ppos, unsigned *src) | |
| 88 | { | ||
| 89 | int r, pos; | ||
| 90 | |||
| 91 | ✗ | pos = *ppos; | |
| 92 | ✗ | pos += bits; | |
| 93 | ✗ | r = src[(pos - 1) / 32] >> ((-pos) & 31); | |
| 94 | ✗ | *ppos = pos; | |
| 95 | |||
| 96 | ✗ | return r & ((1 << bits) - 1); | |
| 97 | } | ||
| 98 | |||
| 99 | static const uint8_t bits[8] = { 6, 6, 5, 5, 4, 0, 3, 3, }; | ||
| 100 | |||
| 101 | ✗ | static void set_sample(int i, int j, int v, float *result, int *pads, float value) | |
| 102 | { | ||
| 103 | ✗ | result[i * 64 + pads[i] + j * 3] = value * (2 * v - 7); | |
| 104 | ✗ | } | |
| 105 | |||
| 106 | ✗ | static int fastaudio_decode(AVCodecContext *avctx, AVFrame *frame, | |
| 107 | int *got_frame, AVPacket *pkt) | ||
| 108 | { | ||
| 109 | ✗ | FastAudioContext *s = avctx->priv_data; | |
| 110 | GetByteContext gb; | ||
| 111 | int subframes; | ||
| 112 | int ret; | ||
| 113 | |||
| 114 | ✗ | subframes = pkt->size / (40 * avctx->ch_layout.nb_channels); | |
| 115 | ✗ | frame->nb_samples = subframes * 256; | |
| 116 | ✗ | if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) | |
| 117 | ✗ | return ret; | |
| 118 | |||
| 119 | ✗ | bytestream2_init(&gb, pkt->data, pkt->size); | |
| 120 | |||
| 121 | ✗ | for (int subframe = 0; subframe < subframes; subframe++) { | |
| 122 | ✗ | for (int channel = 0; channel < avctx->ch_layout.nb_channels; channel++) { | |
| 123 | ✗ | ChannelItems *ch = &s->ch[channel]; | |
| 124 | ✗ | float result[256] = { 0 }; | |
| 125 | unsigned src[10]; | ||
| 126 | int inds[4], pads[4]; | ||
| 127 | float m[8]; | ||
| 128 | ✗ | int pos = 0; | |
| 129 | |||
| 130 | ✗ | for (int i = 0; i < 10; i++) | |
| 131 | ✗ | src[i] = bytestream2_get_le32(&gb); | |
| 132 | |||
| 133 | ✗ | for (int i = 0; i < 8; i++) | |
| 134 | ✗ | m[7 - i] = s->table[i][read_bits(bits[i], &pos, src)]; | |
| 135 | |||
| 136 | ✗ | for (int i = 0; i < 4; i++) | |
| 137 | ✗ | inds[3 - i] = read_bits(6, &pos, src); | |
| 138 | |||
| 139 | ✗ | for (int i = 0; i < 4; i++) | |
| 140 | ✗ | pads[3 - i] = read_bits(2, &pos, src); | |
| 141 | |||
| 142 | ✗ | for (int i = 0, index5 = 0; i < 4; i++) { | |
| 143 | ✗ | float value = av_int2float((inds[i] + 1) << 20) * powf(2.f, 116.f); | |
| 144 | |||
| 145 | ✗ | for (int j = 0, tmp = 0; j < 21; j++) { | |
| 146 | ✗ | set_sample(i, j, j == 20 ? tmp / 2 : read_bits(3, &pos, src), result, pads, value); | |
| 147 | ✗ | if (j % 10 == 9) | |
| 148 | ✗ | tmp = 4 * tmp + read_bits(2, &pos, src); | |
| 149 | ✗ | if (j == 20) | |
| 150 | ✗ | index5 = FFMIN(2 * index5 + tmp % 2, 63); | |
| 151 | } | ||
| 152 | |||
| 153 | ✗ | m[2] = s->table[5][index5]; | |
| 154 | } | ||
| 155 | |||
| 156 | ✗ | for (int i = 0; i < 256; i++) { | |
| 157 | ✗ | float x = result[i]; | |
| 158 | |||
| 159 | ✗ | for (int j = 0; j < 8; j++) { | |
| 160 | ✗ | x -= m[j] * ch->f[j]; | |
| 161 | ✗ | ch->f[j] += m[j] * x; | |
| 162 | } | ||
| 163 | |||
| 164 | ✗ | memmove(&ch->f[0], &ch->f[1], sizeof(float) * 7); | |
| 165 | ✗ | ch->f[7] = x; | |
| 166 | ✗ | ch->last = x + ch->last * 0.86f; | |
| 167 | ✗ | result[i] = ch->last * 2.f; | |
| 168 | } | ||
| 169 | |||
| 170 | ✗ | memcpy(frame->extended_data[channel] + 1024 * subframe, result, 256 * sizeof(float)); | |
| 171 | } | ||
| 172 | } | ||
| 173 | |||
| 174 | ✗ | *got_frame = 1; | |
| 175 | |||
| 176 | ✗ | return pkt->size; | |
| 177 | } | ||
| 178 | |||
| 179 | ✗ | static av_cold int fastaudio_close(AVCodecContext *avctx) | |
| 180 | { | ||
| 181 | ✗ | FastAudioContext *s = avctx->priv_data; | |
| 182 | |||
| 183 | ✗ | av_freep(&s->ch); | |
| 184 | |||
| 185 | ✗ | return 0; | |
| 186 | } | ||
| 187 | |||
| 188 | const FFCodec ff_fastaudio_decoder = { | ||
| 189 | .p.name = "fastaudio", | ||
| 190 | CODEC_LONG_NAME("MobiClip FastAudio"), | ||
| 191 | .p.type = AVMEDIA_TYPE_AUDIO, | ||
| 192 | .p.id = AV_CODEC_ID_FASTAUDIO, | ||
| 193 | .priv_data_size = sizeof(FastAudioContext), | ||
| 194 | .init = fastaudio_init, | ||
| 195 | FF_CODEC_DECODE_CB(fastaudio_decode), | ||
| 196 | .close = fastaudio_close, | ||
| 197 | .p.capabilities = AV_CODEC_CAP_DR1, | ||
| 198 | .p.sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP, | ||
| 199 | AV_SAMPLE_FMT_NONE }, | ||
| 200 | }; | ||
| 201 |