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FFmpeg/libavcodec/ttaenc.c
Andreas Rheinhardt 56e9e0273a avcodec/encode: Always use intermediate buffer in ff_alloc_packet2()
Up until now, ff_alloc_packet2() has a min_size parameter:
It is supposed to be a lower bound on the final size of the packet
to allocate. If it is not too far from the upper bound (namely,
if it is at least half the upper bound), then ff_alloc_packet2()
already allocates the final, already refcounted packet; if it is
not, then the packet is not refcounted and its data only points to
a buffer owned by the AVCodecContext (in this case, the packet will
be made refcounted in encode_simple_internal() in libavcodec/encode.c).
The goal of this was to avoid data copies and intermediate buffers
if one has a precise lower bound.

Yet those encoders for which precise lower bounds exist have recently
been switched to ff_get_encode_buffer() (which automatically allocates
final buffers), leaving only two encoders to actually set the min_size
to something else than zero (namely aliaspixenc and hapenc). Both of
these encoders use a very low lower bound that is not helpful in any
nontrivial case.

This commit therefore removes the min_size parameter as well as the
codepath in ff_alloc_packet2() for the allocation of final buffers.
Furthermore, the function has been renamed to ff_alloc_packet() and
moved to encode.h alongside ff_get_encode_buffer().

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
2021-06-08 12:52:50 +02:00

220 lines
6.9 KiB
C

/*
* 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 "encode.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_packet(avctx, avpkt, pkt_size)) < 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, (1U << 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_bytes_output(&pb);
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;
}
const 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,
.sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_U8,
AV_SAMPLE_FMT_S16,
AV_SAMPLE_FMT_S32,
AV_SAMPLE_FMT_NONE },
.caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
};