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ffmpeg/libavcodec/hcadec.c

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/*
* 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
*/
#include "libavutil/crc.h"
#include "libavutil/float_dsp.h"
#include "libavutil/intreadwrite.h"
#include "libavutil/tx.h"
#include "avcodec.h"
#include "get_bits.h"
#include "internal.h"
#include "hca_data.h"
typedef struct ChannelContext {
float base[128];
DECLARE_ALIGNED(32, float, imdct_in)[128];
DECLARE_ALIGNED(32, float, imdct_out)[128];
DECLARE_ALIGNED(32, float, imdct_prev)[128];
int8_t scale_factors[128];
uint8_t scale[128];
int8_t intensity[8];
int8_t *hfr_scale;
unsigned count;
int chan_type;
} ChannelContext;
typedef struct HCAContext {
GetBitContext gb;
const AVCRC *crc_table;
ChannelContext ch[16];
uint8_t ath[128];
int ath_type;
unsigned hfr_group_count;
uint8_t track_count;
uint8_t channel_config;
uint8_t total_band_count;
uint8_t base_band_count;
uint8_t stereo_band_count;
uint8_t bands_per_hfr_group;
av_tx_fn tx_fn;
AVTXContext *tx_ctx;
AVFloatDSPContext *fdsp;
} HCAContext;
static void ath_init1(uint8_t *ath, int sample_rate)
{
unsigned int index;
unsigned int acc = 0;
for (int i = 0; i < 128; i++) {
acc += sample_rate;
index = acc >> 13;
if (index >= 654) {
memset(ath+i, 0xFF, (128 - i));
break;
}
ath[i] = ath_base_curve[index];
}
}
static int ath_init(uint8_t *ath, int type, int sample_rate)
{
switch (type) {
case 0:
/* nothing to do */
break;
case 1:
ath_init1(ath, sample_rate);
break;
default:
return AVERROR_INVALIDDATA;
}
return 0;
}
static inline unsigned ceil2(unsigned a, unsigned b)
{
return (b > 0) ? (a / b + ((a % b) ? 1 : 0)) : 0;
}
static av_cold int decode_init(AVCodecContext *avctx)
{
HCAContext *c = avctx->priv_data;
GetBitContext *gb = &c->gb;
int8_t r[16] = { 0 };
float scale = 1.f / 8.f;
unsigned b, chunk;
int version, ret;
avctx->sample_fmt = AV_SAMPLE_FMT_FLTP;
c->crc_table = av_crc_get_table(AV_CRC_16_ANSI);
if (avctx->channels <= 0 || avctx->channels > 16)
return AVERROR(EINVAL);
ret = init_get_bits8(gb, avctx->extradata, avctx->extradata_size);
if (ret < 0)
return ret;
skip_bits_long(gb, 32);
version = get_bits(gb, 16);
skip_bits_long(gb, 16);
c->ath_type = version >= 0x200 ? 0 : 1;
if (get_bits_long(gb, 32) != MKBETAG('f', 'm', 't', 0))
return AVERROR_INVALIDDATA;
skip_bits_long(gb, 32);
skip_bits_long(gb, 32);
skip_bits_long(gb, 32);
chunk = get_bits_long(gb, 32);
if (chunk == MKBETAG('c', 'o', 'm', 'p')) {
skip_bits_long(gb, 16);
skip_bits_long(gb, 8);
skip_bits_long(gb, 8);
c->track_count = get_bits(gb, 8);
c->channel_config = get_bits(gb, 8);
c->total_band_count = get_bits(gb, 8);
c->base_band_count = get_bits(gb, 8);
c->stereo_band_count = get_bits(gb, 8);
c->bands_per_hfr_group = get_bits(gb, 8);
} else if (chunk == MKBETAG('d', 'e', 'c', 0)) {
skip_bits_long(gb, 16);
skip_bits_long(gb, 8);
skip_bits_long(gb, 8);
c->total_band_count = get_bits(gb, 8) + 1;
c->base_band_count = get_bits(gb, 8) + 1;
c->track_count = get_bits(gb, 4);
c->channel_config = get_bits(gb, 4);
if (!get_bits(gb, 8))
c->base_band_count = c->total_band_count;
c->stereo_band_count = c->total_band_count - c->base_band_count;
c->bands_per_hfr_group = 0;
} else
return AVERROR_INVALIDDATA;
if (c->total_band_count > FF_ARRAY_ELEMS(c->ch->imdct_in))
return AVERROR_INVALIDDATA;
while (get_bits_left(gb) >= 32) {
chunk = get_bits_long(gb, 32);
if (chunk == MKBETAG('v', 'b', 'r', 0)) {
skip_bits_long(gb, 16);
skip_bits_long(gb, 16);
} else if (chunk == MKBETAG('a', 't', 'h', 0)) {
c->ath_type = get_bits(gb, 16);
} else if (chunk == MKBETAG('r', 'v', 'a', 0)) {
skip_bits_long(gb, 32);
} else if (chunk == MKBETAG('c', 'o', 'm', 'm')) {
skip_bits_long(gb, get_bits(gb, 8) * 8);
} else if (chunk == MKBETAG('c', 'i', 'p', 'h')) {
skip_bits_long(gb, 16);
} else if (chunk == MKBETAG('l', 'o', 'o', 'p')) {
skip_bits_long(gb, 32);
skip_bits_long(gb, 32);
skip_bits_long(gb, 16);
skip_bits_long(gb, 16);
} else if (chunk == MKBETAG('p', 'a', 'd', 0)) {
break;
} else {
break;
}
}
ret = ath_init(c->ath, c->ath_type, avctx->sample_rate);
if (ret < 0)
return ret;
if (!c->track_count)
c->track_count = 1;
b = avctx->channels / c->track_count;
if (c->stereo_band_count && b > 1) {
int8_t *x = r;
for (int i = 0; i < c->track_count; i++, x+=b) {
switch (b) {
case 2:
case 3:
x[0] = 1;
x[1] = 2;
break;
case 4:
x[0]=1; x[1] = 2;
if (c->channel_config == 0) {
x[2]=1;
x[3]=2;
}
break;
case 5:
x[0]=1; x[1] = 2;
if (c->channel_config <= 2) {
x[3]=1;
x[4]=2;
}
break;
case 6:
case 7:
x[0] = 1; x[1] = 2; x[4] = 1; x[5] = 2;
break;
case 8:
x[0] = 1; x[1] = 2; x[4] = 1; x[5] = 2; x[6] = 1; x[7] = 2;
break;
}
}
}
if (c->total_band_count < c->base_band_count)
return AVERROR_INVALIDDATA;
c->hfr_group_count = ceil2(c->total_band_count - (c->base_band_count + c->stereo_band_count),
c->bands_per_hfr_group);
if (c->base_band_count + c->stereo_band_count + (unsigned long)c->hfr_group_count > 128ULL)
return AVERROR_INVALIDDATA;
for (int i = 0; i < avctx->channels; i++) {
c->ch[i].chan_type = r[i];
c->ch[i].count = c->base_band_count + ((r[i] != 2) ? c->stereo_band_count : 0);
c->ch[i].hfr_scale = &c->ch[i].scale_factors[c->base_band_count + c->stereo_band_count];
if (c->ch[i].count > 128)
return AVERROR_INVALIDDATA;
}
c->fdsp = avpriv_float_dsp_alloc(avctx->flags & AV_CODEC_FLAG_BITEXACT);
if (!c->fdsp)
return AVERROR(ENOMEM);
return av_tx_init(&c->tx_ctx, &c->tx_fn, AV_TX_FLOAT_MDCT, 1, 128, &scale, 0);
}
static void run_imdct(HCAContext *c, ChannelContext *ch, int index, float *out)
{
c->tx_fn(c->tx_ctx, ch->imdct_out, ch->imdct_in, sizeof(float));
c->fdsp->vector_fmul_window(out, ch->imdct_prev + (128 >> 1),
ch->imdct_out, window, 128 >> 1);
memcpy(ch->imdct_prev, ch->imdct_out, 128 * sizeof(float));
}
static void apply_intensity_stereo(HCAContext *s, ChannelContext *ch1, ChannelContext *ch2,
int index, unsigned band_count, unsigned base_band_count,
unsigned stereo_band_count)
{
float ratio_l = intensity_ratio_table[ch2->intensity[index]];
float ratio_r = ratio_l - 2.0f;
float *c1 = &ch1->imdct_in[base_band_count];
float *c2 = &ch2->imdct_in[base_band_count];
if (ch1->chan_type != 1 || !stereo_band_count)
return;
for (int i = 0; i < band_count; i++) {
*(c2++) = *c1 * ratio_r;
*(c1++) *= ratio_l;
}
}
static void reconstruct_hfr(HCAContext *s, ChannelContext *ch,
unsigned hfr_group_count,
unsigned bands_per_hfr_group,
unsigned start_band, unsigned total_band_count)
{
if (ch->chan_type == 2 || !bands_per_hfr_group)
return;
for (int i = 0, k = start_band, l = start_band - 1; i < hfr_group_count; i++){
for (int j = 0; j < bands_per_hfr_group && k < total_band_count && l >= 0; j++, k++, l--){
ch->imdct_in[k] = scale_conversion_table[ scale_conv_bias +
av_clip_intp2(ch->hfr_scale[i] - ch->scale_factors[l], 6) ] * ch->imdct_in[l];
}
}
ch->imdct_in[127] = 0;
}
static void dequantize_coefficients(HCAContext *c, ChannelContext *ch)
{
GetBitContext *gb = &c->gb;
for (int i = 0; i < ch->count; i++) {
unsigned scale = ch->scale[i];
int nb_bits = max_bits_table[scale];
int value = get_bitsz(gb, nb_bits);
float factor;
if (scale > 7) {
value = (1 - ((value & 1) << 1)) * (value >> 1);
if (!value)
skip_bits_long(gb, -1);
factor = value;
} else {
value += scale << 4;
skip_bits_long(gb, quant_spectrum_bits[value] - nb_bits);
factor = quant_spectrum_value[value];
}
ch->imdct_in[i] = factor * ch->base[i];
}
memset(ch->imdct_in + ch->count, 0, sizeof(ch->imdct_in) - ch->count * sizeof(ch->imdct_in[0]));
}
static void unpack(HCAContext *c, ChannelContext *ch,
unsigned hfr_group_count,
int packed_noise_level,
const uint8_t *ath)
{
GetBitContext *gb = &c->gb;
int delta_bits = get_bits(gb, 3);
if (delta_bits > 5) {
for (int i = 0; i < ch->count; i++)
ch->scale_factors[i] = get_bits(gb, 6);
} else if (delta_bits) {
int factor = get_bits(gb, 6);
int max_value = (1 << delta_bits) - 1;
int half_max = max_value >> 1;
ch->scale_factors[0] = factor;
for (int i = 1; i < ch->count; i++){
int delta = get_bits(gb, delta_bits);
if (delta == max_value) {
factor = get_bits(gb, 6);
} else {
factor += delta - half_max;
}
factor = av_clip_uintp2(factor, 6);
ch->scale_factors[i] = factor;
}
} else {
memset(ch->scale_factors, 0, 128);
}
if (ch->chan_type == 2){
ch->intensity[0] = get_bits(gb, 4);
if (ch->intensity[0] < 15) {
for (int i = 1; i < 8; i++)
ch->intensity[i] = get_bits(gb, 4);
}
} else {
for (int i = 0; i < hfr_group_count; i++)
ch->hfr_scale[i] = get_bits(gb, 6);
}
for (int i = 0; i < ch->count; i++) {
int scale = ch->scale_factors[i];
if (scale) {
scale = c->ath[i] + ((packed_noise_level + i) >> 8) - ((scale * 5) >> 1) + 2;
scale = scale_table[av_clip(scale, 0, 58)];
}
ch->scale[i] = scale;
}
memset(ch->scale + ch->count, 0, sizeof(ch->scale) - ch->count);
for (int i = 0; i < ch->count; i++)
ch->base[i] = dequantizer_scaling_table[ch->scale_factors[i]] * quant_step_size[ch->scale[i]];
}
static int decode_frame(AVCodecContext *avctx, void *data,
int *got_frame_ptr, AVPacket *avpkt)
{
AVFrame *frame = data;
HCAContext *c = avctx->priv_data;
int ch, ret, packed_noise_level;
GetBitContext *gb = &c->gb;
float **samples;
if (avctx->err_recognition & AV_EF_CRCCHECK) {
if (av_crc(c->crc_table, 0, avpkt->data, avpkt->size))
return AVERROR_INVALIDDATA;
}
if ((ret = init_get_bits8(gb, avpkt->data, avpkt->size)) < 0)
return ret;
if (get_bits(gb, 16) != 0xFFFF)
return AVERROR_INVALIDDATA;
frame->nb_samples = 1024;
if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
return ret;
samples = (float **)frame->extended_data;
packed_noise_level = (get_bits(gb, 9) << 8) - get_bits(gb, 7);
for (ch = 0; ch < avctx->channels; ch++)
unpack(c, &c->ch[ch], c->hfr_group_count, packed_noise_level, c->ath);
for (int i = 0; i < 8; i++) {
for (ch = 0; ch < avctx->channels; ch++)
dequantize_coefficients(c, &c->ch[ch]);
for (ch = 0; ch < avctx->channels; ch++)
reconstruct_hfr(c, &c->ch[ch], c->hfr_group_count, c->bands_per_hfr_group,
c->stereo_band_count + c->base_band_count, c->total_band_count);
for (ch = 0; ch < avctx->channels - 1; ch++)
apply_intensity_stereo(c, &c->ch[ch], &c->ch[ch+1], i,
c->total_band_count - c->base_band_count,
c->base_band_count, c->stereo_band_count);
for (ch = 0; ch < avctx->channels; ch++)
run_imdct(c, &c->ch[ch], i, samples[ch] + i * 128);
}
*got_frame_ptr = 1;
return avpkt->size;
}
static av_cold int decode_close(AVCodecContext *avctx)
{
HCAContext *c = avctx->priv_data;
av_freep(&c->fdsp);
av_tx_uninit(&c->tx_ctx);
return 0;
}
AVCodec ff_hca_decoder = {
.name = "hca",
.long_name = NULL_IF_CONFIG_SMALL("CRI HCA"),
.type = AVMEDIA_TYPE_AUDIO,
.id = AV_CODEC_ID_HCA,
.priv_data_size = sizeof(HCAContext),
.init = decode_init,
.decode = decode_frame,
.close = decode_close,
.capabilities = AV_CODEC_CAP_DR1,
.sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
AV_SAMPLE_FMT_NONE },
};
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