FFmpeg/libavcodec/dolby_e_parse.c
Andreas Rheinhardt 44e27d937d avcodec/dolby_e: Avoid duplicating sample rate table
Set the sample rate when parsing the header instead and only copy the
value in the decoder and the parser.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
2021-01-30 05:14:45 +01:00

181 lines
5.3 KiB
C

/*
* Copyright (C) 2017 foo86
*
* 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 "get_bits.h"
#include "put_bits.h"
#include "dolby_e.h"
static const uint8_t nb_programs_tab[MAX_PROG_CONF + 1] = {
2, 3, 2, 3, 4, 5, 4, 5, 6, 7, 8, 1, 2, 3, 3, 4, 5, 6, 1, 2, 3, 4, 1, 1
};
static const uint8_t nb_channels_tab[MAX_PROG_CONF + 1] = {
8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 6, 6, 6, 6, 6, 6, 6, 4, 4, 4, 4, 8, 8
};
static const uint16_t sample_rate_tab[16] = {
0, 42965, 43008, 44800, 53706, 53760
};
static int skip_input(DBEContext *s, int nb_words)
{
if (nb_words > s->input_size) {
return AVERROR_INVALIDDATA;
}
s->input += nb_words * s->word_bytes;
s->input_size -= nb_words;
return 0;
}
static int parse_key(DBEContext *s)
{
if (s->key_present) {
const uint8_t *key = s->input;
int ret = skip_input(s, 1);
if (ret < 0)
return ret;
return AV_RB24(key) >> 24 - s->word_bits;
}
return 0;
}
int ff_dolby_e_convert_input(DBEContext *s, int nb_words, int key)
{
const uint8_t *src = s->input;
uint8_t *dst = s->buffer;
PutBitContext pb;
int i;
av_assert0(nb_words <= 1024u);
if (nb_words > s->input_size) {
if (s->avctx)
av_log(s->avctx, AV_LOG_ERROR, "Packet too short\n");
return AVERROR_INVALIDDATA;
}
switch (s->word_bits) {
case 16:
for (i = 0; i < nb_words; i++, src += 2, dst += 2)
AV_WB16(dst, AV_RB16(src) ^ key);
break;
case 20:
init_put_bits(&pb, s->buffer, sizeof(s->buffer));
for (i = 0; i < nb_words; i++, src += 3)
put_bits(&pb, 20, AV_RB24(src) >> 4 ^ key);
flush_put_bits(&pb);
break;
case 24:
for (i = 0; i < nb_words; i++, src += 3, dst += 3)
AV_WB24(dst, AV_RB24(src) ^ key);
break;
default:
av_assert0(0);
}
return init_get_bits(&s->gb, s->buffer, nb_words * s->word_bits);
}
int ff_dolby_e_parse_header(DBEContext *s, const uint8_t *buf, int buf_size)
{
DolbyEHeaderInfo *const header = &s->metadata;
int hdr, ret, key, mtd_size;
if (buf_size < 3)
return AVERROR_INVALIDDATA;
hdr = AV_RB24(buf);
if ((hdr & 0xfffffe) == 0x7888e) {
s->word_bits = 24;
} else if ((hdr & 0xffffe0) == 0x788e0) {
s->word_bits = 20;
} else if ((hdr & 0xfffe00) == 0x78e00) {
s->word_bits = 16;
} else {
if (s->avctx)
av_log(s->avctx, AV_LOG_ERROR, "Invalid frame header\n");
return AVERROR_INVALIDDATA;
}
s->word_bytes = s->word_bits + 7 >> 3;
s->input = buf + s->word_bytes;
s->input_size = buf_size / s->word_bytes - 1;
s->key_present = hdr >> 24 - s->word_bits & 1;
if ((key = parse_key(s)) < 0)
return key;
if ((ret = ff_dolby_e_convert_input(s, 1, key)) < 0)
return ret;
skip_bits(&s->gb, 4);
mtd_size = get_bits(&s->gb, 10);
if (!mtd_size) {
if (s->avctx)
av_log(s->avctx, AV_LOG_ERROR, "Invalid metadata size\n");
return AVERROR_INVALIDDATA;
}
if ((ret = ff_dolby_e_convert_input(s, mtd_size, key)) < 0)
return ret;
skip_bits(&s->gb, 14);
header->prog_conf = get_bits(&s->gb, 6);
if (header->prog_conf > MAX_PROG_CONF) {
if (s->avctx)
av_log(s->avctx, AV_LOG_ERROR, "Invalid program configuration\n");
return AVERROR_INVALIDDATA;
}
header->nb_channels = nb_channels_tab[header->prog_conf];
header->nb_programs = nb_programs_tab[header->prog_conf];
header->fr_code = get_bits(&s->gb, 4);
header->fr_code_orig = get_bits(&s->gb, 4);
if (!(header->sample_rate = sample_rate_tab[header->fr_code]) ||
!sample_rate_tab[header->fr_code_orig]) {
if (s->avctx)
av_log(s->avctx, AV_LOG_ERROR, "Invalid frame rate code\n");
return AVERROR_INVALIDDATA;
}
skip_bits_long(&s->gb, 88);
for (int i = 0; i < header->nb_channels; i++)
header->ch_size[i] = get_bits(&s->gb, 10);
header->mtd_ext_size = get_bits(&s->gb, 8);
header->meter_size = get_bits(&s->gb, 8);
skip_bits_long(&s->gb, 10 * header->nb_programs);
for (int i = 0; i < header->nb_channels; i++) {
header->rev_id[i] = get_bits(&s->gb, 4);
skip_bits1(&s->gb);
header->begin_gain[i] = get_bits(&s->gb, 10);
header->end_gain[i] = get_bits(&s->gb, 10);
}
if (get_bits_left(&s->gb) < 0) {
if (s->avctx)
av_log(s->avctx, AV_LOG_ERROR, "Read past end of metadata\n");
return AVERROR_INVALIDDATA;
}
return skip_input(s, mtd_size + 1);
}