| 1 | /* |
| 2 | * TTA (The Lossless True Audio) encoder |
| 3 | * |
| 4 | * This file is part of FFmpeg. |
| 5 | * |
| 6 | * FFmpeg is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU Lesser General Public |
| 8 | * License as published by the Free Software Foundation; either |
| 9 | * version 2.1 of the License, or (at your option) any later version. |
| 10 | * |
| 11 | * FFmpeg is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 14 | * Lesser General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU Lesser General Public |
| 17 | * License along with FFmpeg; if not, write to the Free Software |
| 18 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 19 | */ |
| 20 | |
| 21 | #define BITSTREAM_WRITER_LE |
| 22 | #include "ttadata.h" |
| 23 | #include "avcodec.h" |
| 24 | #include "put_bits.h" |
| 25 | #include "internal.h" |
| 26 | #include "libavutil/crc.h" |
| 27 | |
| 28 | typedef struct TTAEncContext { |
| 29 | const AVCRC *crc_table; |
| 30 | int bps; |
| 31 | TTAChannel *ch_ctx; |
| 32 | } TTAEncContext; |
| 33 | |
| 34 | static av_cold int tta_encode_init(AVCodecContext *avctx) |
| 35 | { |
| 36 | TTAEncContext *s = avctx->priv_data; |
| 37 | |
| 38 | s->crc_table = av_crc_get_table(AV_CRC_32_IEEE_LE); |
| 39 | |
| 40 | switch (avctx->sample_fmt) { |
| 41 | case AV_SAMPLE_FMT_U8: |
| 42 | avctx->bits_per_raw_sample = 8; |
| 43 | break; |
| 44 | case AV_SAMPLE_FMT_S16: |
| 45 | avctx->bits_per_raw_sample = 16; |
| 46 | break; |
| 47 | case AV_SAMPLE_FMT_S32: |
| 48 | if (avctx->bits_per_raw_sample > 24) |
| 49 | av_log(avctx, AV_LOG_WARNING, "encoding as 24 bits-per-sample\n"); |
| 50 | avctx->bits_per_raw_sample = 24; |
| 51 | } |
| 52 | |
| 53 | s->bps = avctx->bits_per_raw_sample >> 3; |
| 54 | avctx->frame_size = 256 * avctx->sample_rate / 245; |
| 55 | |
| 56 | s->ch_ctx = av_malloc_array(avctx->channels, sizeof(*s->ch_ctx)); |
| 57 | if (!s->ch_ctx) |
| 58 | return AVERROR(ENOMEM); |
| 59 | |
| 60 | return 0; |
| 61 | } |
| 62 | |
| 63 | static inline void ttafilter_process(TTAFilter *c, int32_t *in) |
| 64 | { |
| 65 | register int32_t *dl = c->dl, *qm = c->qm, *dx = c->dx, sum = c->round; |
| 66 | |
| 67 | if (c->error < 0) { |
| 68 | qm[0] -= dx[0]; qm[1] -= dx[1]; qm[2] -= dx[2]; qm[3] -= dx[3]; |
| 69 | qm[4] -= dx[4]; qm[5] -= dx[5]; qm[6] -= dx[6]; qm[7] -= dx[7]; |
| 70 | } else if (c->error > 0) { |
| 71 | qm[0] += dx[0]; qm[1] += dx[1]; qm[2] += dx[2]; qm[3] += dx[3]; |
| 72 | qm[4] += dx[4]; qm[5] += dx[5]; qm[6] += dx[6]; qm[7] += dx[7]; |
| 73 | } |
| 74 | |
| 75 | sum += dl[0] * qm[0] + dl[1] * qm[1] + dl[2] * qm[2] + dl[3] * qm[3] + |
| 76 | dl[4] * qm[4] + dl[5] * qm[5] + dl[6] * qm[6] + dl[7] * qm[7]; |
| 77 | |
| 78 | dx[0] = dx[1]; dx[1] = dx[2]; dx[2] = dx[3]; dx[3] = dx[4]; |
| 79 | dl[0] = dl[1]; dl[1] = dl[2]; dl[2] = dl[3]; dl[3] = dl[4]; |
| 80 | |
| 81 | dx[4] = ((dl[4] >> 30) | 1); |
| 82 | dx[5] = ((dl[5] >> 30) | 2) & ~1; |
| 83 | dx[6] = ((dl[6] >> 30) | 2) & ~1; |
| 84 | dx[7] = ((dl[7] >> 30) | 4) & ~3; |
| 85 | |
| 86 | dl[4] = -dl[5]; dl[5] = -dl[6]; |
| 87 | dl[6] = *in - dl[7]; dl[7] = *in; |
| 88 | dl[5] += dl[6]; dl[4] += dl[5]; |
| 89 | |
| 90 | *in -= (sum >> c->shift); |
| 91 | c->error = *in; |
| 92 | } |
| 93 | |
| 94 | static int32_t get_sample(const AVFrame *frame, int sample, |
| 95 | enum AVSampleFormat format) |
| 96 | { |
| 97 | int32_t ret; |
| 98 | |
| 99 | if (format == AV_SAMPLE_FMT_U8) { |
| 100 | ret = frame->data[0][sample] - 0x80; |
| 101 | } else if (format == AV_SAMPLE_FMT_S16) { |
| 102 | const int16_t *ptr = (const int16_t *)frame->data[0]; |
| 103 | ret = ptr[sample]; |
| 104 | } else { |
| 105 | const int32_t *ptr = (const int32_t *)frame->data[0]; |
| 106 | ret = ptr[sample] >> 8; |
| 107 | } |
| 108 | |
| 109 | return ret; |
| 110 | } |
| 111 | |
| 112 | static int tta_encode_frame(AVCodecContext *avctx, AVPacket *avpkt, |
| 113 | const AVFrame *frame, int *got_packet_ptr) |
| 114 | { |
| 115 | TTAEncContext *s = avctx->priv_data; |
| 116 | PutBitContext pb; |
| 117 | int ret, i, out_bytes, cur_chan = 0, res = 0, samples = 0; |
| 118 | |
| 119 | if ((ret = ff_alloc_packet2(avctx, avpkt, frame->nb_samples * 2 * avctx->channels * s->bps)) < 0) |
| 120 | return ret; |
| 121 | init_put_bits(&pb, avpkt->data, avpkt->size); |
| 122 | |
| 123 | // init per channel states |
| 124 | for (i = 0; i < avctx->channels; i++) { |
| 125 | s->ch_ctx[i].predictor = 0; |
| 126 | ff_tta_filter_init(&s->ch_ctx[i].filter, ff_tta_filter_configs[s->bps - 1]); |
| 127 | ff_tta_rice_init(&s->ch_ctx[i].rice, 10, 10); |
| 128 | } |
| 129 | |
| 130 | for (i = 0; i < frame->nb_samples * avctx->channels; i++) { |
| 131 | TTAChannel *c = &s->ch_ctx[cur_chan]; |
| 132 | TTAFilter *filter = &c->filter; |
| 133 | TTARice *rice = &c->rice; |
| 134 | uint32_t k, unary, outval; |
| 135 | int32_t value, temp; |
| 136 | |
| 137 | value = get_sample(frame, samples++, avctx->sample_fmt); |
| 138 | |
| 139 | if (avctx->channels > 1) { |
| 140 | if (cur_chan < avctx->channels - 1) |
| 141 | value = res = get_sample(frame, samples, avctx->sample_fmt) - value; |
| 142 | else |
| 143 | value -= res / 2; |
| 144 | } |
| 145 | |
| 146 | temp = value; |
| 147 | #define PRED(x, k) (int32_t)((((uint64_t)(x) << (k)) - (x)) >> (k)) |
| 148 | switch (s->bps) { |
| 149 | case 1: value -= PRED(c->predictor, 4); break; |
| 150 | case 2: |
| 151 | case 3: value -= PRED(c->predictor, 5); break; |
| 152 | } |
| 153 | c->predictor = temp; |
| 154 | |
| 155 | ttafilter_process(filter, &value); |
| 156 | outval = (value > 0) ? (value << 1) - 1: -value << 1; |
| 157 | |
| 158 | k = rice->k0; |
| 159 | |
| 160 | rice->sum0 += outval - (rice->sum0 >> 4); |
| 161 | if (rice->k0 > 0 && rice->sum0 < ff_tta_shift_16[rice->k0]) |
| 162 | rice->k0--; |
| 163 | else if (rice->sum0 > ff_tta_shift_16[rice->k0 + 1]) |
| 164 | rice->k0++; |
| 165 | |
| 166 | if (outval >= ff_tta_shift_1[k]) { |
| 167 | outval -= ff_tta_shift_1[k]; |
| 168 | k = rice->k1; |
| 169 | |
| 170 | rice->sum1 += outval - (rice->sum1 >> 4); |
| 171 | if (rice->k1 > 0 && rice->sum1 < ff_tta_shift_16[rice->k1]) |
| 172 | rice->k1--; |
| 173 | else if (rice->sum1 > ff_tta_shift_16[rice->k1 + 1]) |
| 174 | rice->k1++; |
| 175 | |
| 176 | unary = 1 + (outval >> k); |
| 177 | do { |
| 178 | if (unary > 31) { |
| 179 | put_bits(&pb, 31, 0x7FFFFFFF); |
| 180 | unary -= 31; |
| 181 | } else { |
| 182 | put_bits(&pb, unary, (1 << unary) - 1); |
| 183 | unary = 0; |
| 184 | } |
| 185 | } while (unary); |
| 186 | } |
| 187 | |
| 188 | put_bits(&pb, 1, 0); |
| 189 | |
| 190 | if (k) |
| 191 | put_bits(&pb, k, outval & (ff_tta_shift_1[k] - 1)); |
| 192 | |
| 193 | if (cur_chan < avctx->channels - 1) |
| 194 | cur_chan++; |
| 195 | else |
| 196 | cur_chan = 0; |
| 197 | } |
| 198 | |
| 199 | flush_put_bits(&pb); |
| 200 | out_bytes = put_bits_count(&pb) >> 3; |
| 201 | put_bits32(&pb, av_crc(s->crc_table, UINT32_MAX, avpkt->data, out_bytes) ^ UINT32_MAX); |
| 202 | flush_put_bits(&pb); |
| 203 | |
| 204 | avpkt->pts = frame->pts; |
| 205 | avpkt->size = out_bytes + 4; |
| 206 | avpkt->duration = ff_samples_to_time_base(avctx, frame->nb_samples); |
| 207 | *got_packet_ptr = 1; |
| 208 | return 0; |
| 209 | } |
| 210 | |
| 211 | static av_cold int tta_encode_close(AVCodecContext *avctx) |
| 212 | { |
| 213 | TTAEncContext *s = avctx->priv_data; |
| 214 | av_freep(&s->ch_ctx); |
| 215 | return 0; |
| 216 | } |
| 217 | |
| 218 | AVCodec ff_tta_encoder = { |
| 219 | .name = "tta", |
| 220 | .long_name = NULL_IF_CONFIG_SMALL("TTA (True Audio)"), |
| 221 | .type = AVMEDIA_TYPE_AUDIO, |
| 222 | .id = AV_CODEC_ID_TTA, |
| 223 | .priv_data_size = sizeof(TTAEncContext), |
| 224 | .init = tta_encode_init, |
| 225 | .close = tta_encode_close, |
| 226 | .encode2 = tta_encode_frame, |
| 227 | .capabilities = CODEC_CAP_SMALL_LAST_FRAME | CODEC_CAP_LOSSLESS, |
| 228 | .sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_U8, |
| 229 | AV_SAMPLE_FMT_S16, |
| 230 | AV_SAMPLE_FMT_S32, |
| 231 | AV_SAMPLE_FMT_NONE }, |
| 232 | }; |