/* * TTA (The Lossless True Audio) decoder * Copyright (c) 2006 Alex Beregszaszi * * 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 * TTA (The Lossless True Audio) decoder * @see http://www.true-audio.com/ * @see http://tta.corecodec.org/ * @author Alex Beregszaszi */ #define ALT_BITSTREAM_READER_LE //#define DEBUG #include <limits.h> #include "avcodec.h" #include "get_bits.h" #define FORMAT_INT 1 #define FORMAT_FLOAT 3 #define MAX_ORDER 16 typedef struct TTAFilter { int32_t shift, round, error, mode; int32_t qm[MAX_ORDER]; int32_t dx[MAX_ORDER]; int32_t dl[MAX_ORDER]; } TTAFilter; typedef struct TTARice { uint32_t k0, k1, sum0, sum1; } TTARice; typedef struct TTAChannel { int32_t predictor; TTAFilter filter; TTARice rice; } TTAChannel; typedef struct TTAContext { AVCodecContext *avctx; GetBitContext gb; int flags, channels, bps, is_float, data_length; int frame_length, last_frame_length, total_frames; int32_t *decode_buffer; TTAChannel *ch_ctx; } TTAContext; static const uint32_t shift_1[] = { 0x00000001, 0x00000002, 0x00000004, 0x00000008, 0x00000010, 0x00000020, 0x00000040, 0x00000080, 0x00000100, 0x00000200, 0x00000400, 0x00000800, 0x00001000, 0x00002000, 0x00004000, 0x00008000, 0x00010000, 0x00020000, 0x00040000, 0x00080000, 0x00100000, 0x00200000, 0x00400000, 0x00800000, 0x01000000, 0x02000000, 0x04000000, 0x08000000, 0x10000000, 0x20000000, 0x40000000, 0x80000000, 0x80000000, 0x80000000, 0x80000000, 0x80000000, 0x80000000, 0x80000000, 0x80000000, 0x80000000 }; static const uint32_t * const shift_16 = shift_1 + 4; static const int32_t ttafilter_configs[4][2] = { {10, 1}, {9, 1}, {10, 1}, {12, 0} }; static void ttafilter_init(TTAFilter *c, int32_t shift, int32_t mode) { memset(c, 0, sizeof(TTAFilter)); c->shift = shift; c->round = shift_1[shift-1]; // c->round = 1 << (shift - 1); c->mode = mode; } // FIXME: copy paste from original static inline void memshl(register int32_t *a, register int32_t *b) { *a++ = *b++; *a++ = *b++; *a++ = *b++; *a++ = *b++; *a++ = *b++; *a++ = *b++; *a++ = *b++; *a = *b; } // FIXME: copy paste from original // mode=1 encoder, mode=0 decoder static inline void ttafilter_process(TTAFilter *c, int32_t *in, int32_t mode) { register int32_t *dl = c->dl, *qm = c->qm, *dx = c->dx, sum = c->round; if (!c->error) { sum += *dl++ * *qm, qm++; sum += *dl++ * *qm, qm++; sum += *dl++ * *qm, qm++; sum += *dl++ * *qm, qm++; sum += *dl++ * *qm, qm++; sum += *dl++ * *qm, qm++; sum += *dl++ * *qm, qm++; sum += *dl++ * *qm, qm++; dx += 8; } else if(c->error < 0) { sum += *dl++ * (*qm -= *dx++), qm++; sum += *dl++ * (*qm -= *dx++), qm++; sum += *dl++ * (*qm -= *dx++), qm++; sum += *dl++ * (*qm -= *dx++), qm++; sum += *dl++ * (*qm -= *dx++), qm++; sum += *dl++ * (*qm -= *dx++), qm++; sum += *dl++ * (*qm -= *dx++), qm++; sum += *dl++ * (*qm -= *dx++), qm++; } else { sum += *dl++ * (*qm += *dx++), qm++; sum += *dl++ * (*qm += *dx++), qm++; sum += *dl++ * (*qm += *dx++), qm++; sum += *dl++ * (*qm += *dx++), qm++; sum += *dl++ * (*qm += *dx++), qm++; sum += *dl++ * (*qm += *dx++), qm++; sum += *dl++ * (*qm += *dx++), qm++; sum += *dl++ * (*qm += *dx++), qm++; } *(dx-0) = ((*(dl-1) >> 30) | 1) << 2; *(dx-1) = ((*(dl-2) >> 30) | 1) << 1; *(dx-2) = ((*(dl-3) >> 30) | 1) << 1; *(dx-3) = ((*(dl-4) >> 30) | 1); // compress if (mode) { *dl = *in; *in -= (sum >> c->shift); c->error = *in; } else { c->error = *in; *in += (sum >> c->shift); *dl = *in; } if (c->mode) { *(dl-1) = *dl - *(dl-1); *(dl-2) = *(dl-1) - *(dl-2); *(dl-3) = *(dl-2) - *(dl-3); } memshl(c->dl, c->dl + 1); memshl(c->dx, c->dx + 1); } static void rice_init(TTARice *c, uint32_t k0, uint32_t k1) { c->k0 = k0; c->k1 = k1; c->sum0 = shift_16[k0]; c->sum1 = shift_16[k1]; } static int tta_get_unary(GetBitContext *gb) { int ret = 0; // count ones while(get_bits1(gb)) ret++; return ret; } static const int64_t tta_channel_layouts[7] = { AV_CH_LAYOUT_STEREO, AV_CH_LAYOUT_STEREO|AV_CH_LOW_FREQUENCY, AV_CH_LAYOUT_QUAD, 0, AV_CH_LAYOUT_5POINT1_BACK, AV_CH_LAYOUT_5POINT1_BACK|AV_CH_BACK_CENTER, AV_CH_LAYOUT_7POINT1_WIDE }; static av_cold int tta_decode_init(AVCodecContext * avctx) { TTAContext *s = avctx->priv_data; int i; s->avctx = avctx; // 30bytes includes a seektable with one frame if (avctx->extradata_size < 30) return -1; init_get_bits(&s->gb, avctx->extradata, avctx->extradata_size * 8); if (show_bits_long(&s->gb, 32) == AV_RL32("TTA1")) { /* signature */ skip_bits(&s->gb, 32); // if (get_bits_long(&s->gb, 32) != av_bswap32(AV_RL32("TTA1"))) { // av_log(s->avctx, AV_LOG_ERROR, "Missing magic\n"); // return -1; // } s->flags = get_bits(&s->gb, 16); if (s->flags != 1 && s->flags != 3) { av_log(s->avctx, AV_LOG_ERROR, "Invalid flags\n"); return -1; } s->is_float = (s->flags == FORMAT_FLOAT); avctx->channels = s->channels = get_bits(&s->gb, 16); if (s->channels > 1 && s->channels < 9) avctx->channel_layout = tta_channel_layouts[s->channels-2]; avctx->bits_per_coded_sample = get_bits(&s->gb, 16); s->bps = (avctx->bits_per_coded_sample + 7) / 8; avctx->sample_rate = get_bits_long(&s->gb, 32); if(avctx->sample_rate > 1000000){ //prevent FRAME_TIME * avctx->sample_rate from overflowing and sanity check av_log(avctx, AV_LOG_ERROR, "sample_rate too large\n"); return -1; } s->data_length = get_bits_long(&s->gb, 32); skip_bits(&s->gb, 32); // CRC32 of header if (s->is_float) { avctx->sample_fmt = AV_SAMPLE_FMT_FLT; av_log_ask_for_sample(s->avctx, "Unsupported sample format.\n"); return -1; } else switch(s->bps) { case 1: avctx->sample_fmt = AV_SAMPLE_FMT_U8; break; case 2: avctx->sample_fmt = AV_SAMPLE_FMT_S16; break; case 3: avctx->bits_per_coded_sample = 24; case 4: avctx->sample_fmt = AV_SAMPLE_FMT_S32; break; default: av_log_ask_for_sample(s->avctx, "Invalid/unsupported sample format.\n"); return -1; } // FIXME: horribly broken, but directly from reference source #define FRAME_TIME 1.04489795918367346939 s->frame_length = (int)(FRAME_TIME * avctx->sample_rate); s->last_frame_length = s->data_length % s->frame_length; s->total_frames = s->data_length / s->frame_length + (s->last_frame_length ? 1 : 0); av_log(s->avctx, AV_LOG_DEBUG, "flags: %x chans: %d bps: %d rate: %d block: %d\n", s->flags, avctx->channels, avctx->bits_per_coded_sample, avctx->sample_rate, avctx->block_align); av_log(s->avctx, AV_LOG_DEBUG, "data_length: %d frame_length: %d last: %d total: %d\n", s->data_length, s->frame_length, s->last_frame_length, s->total_frames); // FIXME: seek table for (i = 0; i < s->total_frames; i++) skip_bits(&s->gb, 32); skip_bits(&s->gb, 32); // CRC32 of seektable if(s->frame_length >= UINT_MAX / (s->channels * sizeof(int32_t))){ av_log(avctx, AV_LOG_ERROR, "frame_length too large\n"); return -1; } s->decode_buffer = av_mallocz(sizeof(int32_t)*s->frame_length*s->channels); if (!s->decode_buffer) return AVERROR(ENOMEM); s->ch_ctx = av_malloc(avctx->channels * sizeof(*s->ch_ctx)); if (!s->ch_ctx) return AVERROR(ENOMEM); } else { av_log(avctx, AV_LOG_ERROR, "Wrong extradata present\n"); return -1; } return 0; } static int tta_decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt) { const uint8_t *buf = avpkt->data; int buf_size = avpkt->size; TTAContext *s = avctx->priv_data; int i; init_get_bits(&s->gb, buf, buf_size*8); { int cur_chan = 0, framelen = s->frame_length; int32_t *p; if (*data_size < (framelen * s->channels * av_get_bits_per_sample_fmt(avctx->sample_fmt) / 8)) { av_log(avctx, AV_LOG_ERROR, "Output buffer size is too small.\n"); return -1; } // FIXME: seeking s->total_frames--; if (!s->total_frames && s->last_frame_length) framelen = s->last_frame_length; // init per channel states for (i = 0; i < s->channels; i++) { s->ch_ctx[i].predictor = 0; ttafilter_init(&s->ch_ctx[i].filter, ttafilter_configs[s->bps-1][0], ttafilter_configs[s->bps-1][1]); rice_init(&s->ch_ctx[i].rice, 10, 10); } for (p = s->decode_buffer; p < s->decode_buffer + (framelen * s->channels); p++) { int32_t *predictor = &s->ch_ctx[cur_chan].predictor; TTAFilter *filter = &s->ch_ctx[cur_chan].filter; TTARice *rice = &s->ch_ctx[cur_chan].rice; uint32_t unary, depth, k; int32_t value; unary = tta_get_unary(&s->gb); if (unary == 0) { depth = 0; k = rice->k0; } else { depth = 1; k = rice->k1; unary--; } if (get_bits_left(&s->gb) < k) return -1; if (k) { if (k > MIN_CACHE_BITS) return -1; value = (unary << k) + get_bits(&s->gb, k); } else value = unary; // FIXME: copy paste from original switch (depth) { case 1: rice->sum1 += value - (rice->sum1 >> 4); if (rice->k1 > 0 && rice->sum1 < shift_16[rice->k1]) rice->k1--; else if(rice->sum1 > shift_16[rice->k1 + 1]) rice->k1++; value += shift_1[rice->k0]; default: rice->sum0 += value - (rice->sum0 >> 4); if (rice->k0 > 0 && rice->sum0 < shift_16[rice->k0]) rice->k0--; else if(rice->sum0 > shift_16[rice->k0 + 1]) rice->k0++; } // extract coded value #define UNFOLD(x) (((x)&1) ? (++(x)>>1) : (-(x)>>1)) *p = UNFOLD(value); // run hybrid filter ttafilter_process(filter, p, 0); // fixed order prediction #define PRED(x, k) (int32_t)((((uint64_t)x << k) - x) >> k) switch (s->bps) { case 1: *p += PRED(*predictor, 4); break; case 2: case 3: *p += PRED(*predictor, 5); break; case 4: *p += *predictor; break; } *predictor = *p; /*if ((get_bits_count(&s->gb)+7)/8 > buf_size) { av_log(NULL, AV_LOG_INFO, "overread!!\n"); break; }*/ // flip channels if (cur_chan < (s->channels-1)) cur_chan++; else { // decorrelate in case of stereo integer if (!s->is_float && (s->channels > 1)) { int32_t *r = p - 1; for (*p += *r / 2; r > p - s->channels; r--) *r = *(r + 1) - *r; } cur_chan = 0; } } if (get_bits_left(&s->gb) < 32) return -1; skip_bits(&s->gb, 32); // frame crc // convert to output buffer switch(s->bps) { case 1: { uint8_t *samples = data; for (p = s->decode_buffer; p < s->decode_buffer + (framelen * s->channels); p++) *samples++ = *p + 0x80; *data_size = samples - (uint8_t *)data; break; } case 2: { uint16_t *samples = data; for (p = s->decode_buffer; p < s->decode_buffer + (framelen * s->channels); p++) { // *samples++ = (unsigned char)*p; // *samples++ = (unsigned char)(*p >> 8); *samples++ = *p; } *data_size = (uint8_t *)samples - (uint8_t *)data; break; } case 3: { int32_t *samples = data; for (p = s->decode_buffer; p < s->decode_buffer + (framelen * s->channels); p++) *samples++ = AV_RN32(p) << 8; *data_size = (uint8_t *)samples - (uint8_t *)data; break; } default: av_log(s->avctx, AV_LOG_ERROR, "Error, only 16bit samples supported!\n"); } } // return get_bits_count(&s->gb)+7)/8; return buf_size; } static av_cold int tta_decode_close(AVCodecContext *avctx) { TTAContext *s = avctx->priv_data; av_free(s->decode_buffer); av_freep(&s->ch_ctx); return 0; } AVCodec ff_tta_decoder = { .name = "tta", .type = AVMEDIA_TYPE_AUDIO, .id = CODEC_ID_TTA, .priv_data_size = sizeof(TTAContext), .init = tta_decode_init, .close = tta_decode_close, .decode = tta_decode_frame, .long_name = NULL_IF_CONFIG_SMALL("True Audio (TTA)"), };