This source file includes following definitions.
- tta_encode_init
- ttafilter_process
- get_sample
- tta_encode_frame
- tta_encode_close
#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);
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 },
};