/* * TTA (The Lossless True Audio) encoder * * 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 */ #define BITSTREAM_WRITER_LE #include "ttadata.h" #include "avcodec.h" #include "put_bits.h" #include "internal.h" #include "libavutil/crc.h" typedef struct TTAEncContext { const AVCRC *crc_table; int bps; TTAChannel *ch_ctx; } TTAEncContext; static av_cold int tta_encode_init(AVCodecContext *avctx) { TTAEncContext *s = avctx->priv_data; s->crc_table = av_crc_get_table(AV_CRC_32_IEEE_LE); switch (avctx->sample_fmt) { case AV_SAMPLE_FMT_U8: avctx->bits_per_raw_sample = 8; break; case AV_SAMPLE_FMT_S16: avctx->bits_per_raw_sample = 16; break; case AV_SAMPLE_FMT_S32: if (avctx->bits_per_raw_sample > 24) av_log(avctx, AV_LOG_WARNING, "encoding as 24 bits-per-sample\n"); avctx->bits_per_raw_sample = 24; } s->bps = avctx->bits_per_raw_sample >> 3; avctx->frame_size = 256 * avctx->sample_rate / 245; s->ch_ctx = av_malloc_array(avctx->channels, sizeof(*s->ch_ctx)); if (!s->ch_ctx) return AVERROR(ENOMEM); return 0; } static inline void ttafilter_process(TTAFilter *c, int32_t *in) { register int32_t *dl = c->dl, *qm = c->qm, *dx = c->dx, sum = c->round; if (c->error < 0) { qm[0] -= dx[0]; qm[1] -= dx[1]; qm[2] -= dx[2]; qm[3] -= dx[3]; qm[4] -= dx[4]; qm[5] -= dx[5]; qm[6] -= dx[6]; qm[7] -= dx[7]; } else if (c->error > 0) { qm[0] += dx[0]; qm[1] += dx[1]; qm[2] += dx[2]; qm[3] += dx[3]; qm[4] += dx[4]; qm[5] += dx[5]; qm[6] += dx[6]; qm[7] += dx[7]; } sum += dl[0] * qm[0] + dl[1] * qm[1] + dl[2] * qm[2] + dl[3] * qm[3] + dl[4] * qm[4] + dl[5] * qm[5] + dl[6] * qm[6] + dl[7] * qm[7]; dx[0] = dx[1]; dx[1] = dx[2]; dx[2] = dx[3]; dx[3] = dx[4]; dl[0] = dl[1]; dl[1] = dl[2]; dl[2] = dl[3]; dl[3] = dl[4]; dx[4] = ((dl[4] >> 30) | 1); dx[5] = ((dl[5] >> 30) | 2) & ~1; dx[6] = ((dl[6] >> 30) | 2) & ~1; dx[7] = ((dl[7] >> 30) | 4) & ~3; dl[4] = -dl[5]; dl[5] = -dl[6]; dl[6] = *in - dl[7]; dl[7] = *in; dl[5] += dl[6]; dl[4] += dl[5]; *in -= (sum >> c->shift); c->error = *in; } static int32_t get_sample(const AVFrame *frame, int sample, enum AVSampleFormat format) { int32_t ret; if (format == AV_SAMPLE_FMT_U8) { ret = frame->data[0][sample] - 0x80; } else if (format == AV_SAMPLE_FMT_S16) { const int16_t *ptr = (const int16_t *)frame->data[0]; ret = ptr[sample]; } else { const int32_t *ptr = (const int32_t *)frame->data[0]; ret = ptr[sample] >> 8; } return ret; } static int tta_encode_frame(AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame, int *got_packet_ptr) { TTAEncContext *s = avctx->priv_data; PutBitContext pb; int ret, i, out_bytes, cur_chan = 0, res = 0, samples = 0; if ((ret = ff_alloc_packet2(avctx, avpkt, frame->nb_samples * 2 * avctx->channels * s->bps)) < 0) return ret; init_put_bits(&pb, avpkt->data, avpkt->size); // init per channel states for (i = 0; i < avctx->channels; i++) { s->ch_ctx[i].predictor = 0; ff_tta_filter_init(&s->ch_ctx[i].filter, ff_tta_filter_configs[s->bps - 1]); ff_tta_rice_init(&s->ch_ctx[i].rice, 10, 10); } for (i = 0; i < frame->nb_samples * avctx->channels; i++) { TTAChannel *c = &s->ch_ctx[cur_chan]; TTAFilter *filter = &c->filter; TTARice *rice = &c->rice; uint32_t k, unary, outval; int32_t value, temp; value = get_sample(frame, samples++, avctx->sample_fmt); if (avctx->channels > 1) { if (cur_chan < avctx->channels - 1) value = res = get_sample(frame, samples, avctx->sample_fmt) - value; else value -= res / 2; } temp = value; #define PRED(x, k) (int32_t)((((uint64_t)(x) << (k)) - (x)) >> (k)) switch (s->bps) { case 1: value -= PRED(c->predictor, 4); break; case 2: case 3: value -= PRED(c->predictor, 5); break; } c->predictor = temp; ttafilter_process(filter, &value); outval = (value > 0) ? (value << 1) - 1: -value << 1; k = rice->k0; rice->sum0 += outval - (rice->sum0 >> 4); if (rice->k0 > 0 && rice->sum0 < ff_tta_shift_16[rice->k0]) rice->k0--; else if (rice->sum0 > ff_tta_shift_16[rice->k0 + 1]) rice->k0++; if (outval >= ff_tta_shift_1[k]) { outval -= ff_tta_shift_1[k]; k = rice->k1; rice->sum1 += outval - (rice->sum1 >> 4); if (rice->k1 > 0 && rice->sum1 < ff_tta_shift_16[rice->k1]) rice->k1--; else if (rice->sum1 > ff_tta_shift_16[rice->k1 + 1]) rice->k1++; unary = 1 + (outval >> k); do { if (unary > 31) { put_bits(&pb, 31, 0x7FFFFFFF); unary -= 31; } else { put_bits(&pb, unary, (1 << unary) - 1); unary = 0; } } while (unary); } put_bits(&pb, 1, 0); if (k) put_bits(&pb, k, outval & (ff_tta_shift_1[k] - 1)); if (cur_chan < avctx->channels - 1) cur_chan++; else cur_chan = 0; } flush_put_bits(&pb); out_bytes = put_bits_count(&pb) >> 3; put_bits32(&pb, av_crc(s->crc_table, UINT32_MAX, avpkt->data, out_bytes) ^ UINT32_MAX); flush_put_bits(&pb); avpkt->pts = frame->pts; avpkt->size = out_bytes + 4; avpkt->duration = ff_samples_to_time_base(avctx, frame->nb_samples); *got_packet_ptr = 1; return 0; } static av_cold int tta_encode_close(AVCodecContext *avctx) { TTAEncContext *s = avctx->priv_data; av_freep(&s->ch_ctx); return 0; } AVCodec ff_tta_encoder = { .name = "tta", .long_name = NULL_IF_CONFIG_SMALL("TTA (True Audio)"), .type = AVMEDIA_TYPE_AUDIO, .id = AV_CODEC_ID_TTA, .priv_data_size = sizeof(TTAEncContext), .init = tta_encode_init, .close = tta_encode_close, .encode2 = tta_encode_frame, .capabilities = CODEC_CAP_SMALL_LAST_FRAME | CODEC_CAP_LOSSLESS, .sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_U8, AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_S32, AV_SAMPLE_FMT_NONE }, };