/*
* 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 "ttaencdsp.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;
TTAEncDSPContext dsp;
} 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);
ff_ttaencdsp_init(&s->dsp);
return 0;
}
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, res, samples;
int64_t pkt_size = frame->nb_samples * 2LL * avctx->channels * s->bps;
pkt_alloc:
cur_chan = 0, res = 0, samples = 0;
if ((ret = ff_alloc_packet2(avctx, avpkt, pkt_size, 0)) < 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;
s->dsp.filter_process(filter->qm, filter->dx, filter->dl, &filter->error, &value,
filter->shift, filter->round);
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);
if (unary + 100LL > put_bits_left(&pb)) {
if (pkt_size < INT_MAX/2) {
pkt_size *= 2;
av_packet_unref(avpkt);
goto pkt_alloc;
} else
return AVERROR(ENOMEM);
}
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 = AV_CODEC_CAP_SMALL_LAST_FRAME | AV_CODEC_CAP_LOSSLESS,
.sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_U8,
AV_SAMPLE_FMT_S16,
AV_SAMPLE_FMT_S32,
AV_SAMPLE_FMT_NONE },
};