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mirror of https://github.com/FFmpeg/FFmpeg.git synced 2024-12-23 12:43:46 +02:00
FFmpeg/libavcodec/vima.c
Andreas Rheinhardt 20f9727018 avcodec/codec_internal: Add FFCodec, hide internal part of AVCodec
Up until now, codec.h contains both public and private parts
of AVCodec. This exposes the internals of AVCodec to users
and leads them into the temptation of actually using them
and forces us to forward-declare structures and types that
users can't use at all.

This commit changes this by adding a new structure FFCodec to
codec_internal.h that extends AVCodec, i.e. contains the public
AVCodec as first member; the private fields of AVCodec are moved
to this structure, leaving codec.h clean.

Reviewed-by: Anton Khirnov <anton@khirnov.net>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
2022-03-21 01:33:09 +01:00

221 lines
6.7 KiB
C

/*
* LucasArts VIMA decoder
* Copyright (c) 2012 Paul B Mahol
*
* 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
*/
/**
* @file
* LucasArts VIMA audio decoder
* @author Paul B Mahol
*/
#include "libavutil/channel_layout.h"
#include "libavutil/thread.h"
#include "adpcm_data.h"
#include "avcodec.h"
#include "codec_internal.h"
#include "get_bits.h"
#include "internal.h"
static uint16_t predict_table[5786 * 2];
static const uint8_t size_table[] = {
4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7
};
static const int8_t index_table1[] = {
-1, 4, -1, 4
};
static const int8_t index_table2[] = {
-1, -1, 2, 6, -1, -1, 2, 6
};
static const int8_t index_table3[] = {
-1, -1, -1, -1, 1, 2, 4, 6, -1, -1, -1, -1, 1, 2, 4, 6
};
static const int8_t index_table4[] = {
-1, -1, -1, -1, -1, -1, -1, -1, 1, 1, 1, 2, 2, 4, 5, 6,
-1, -1, -1, -1, -1, -1, -1, -1, 1, 1, 1, 2, 2, 4, 5, 6
};
static const int8_t index_table5[] = {
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
1, 1, 1, 1, 1, 2, 2, 2, 2, 4, 4, 4, 5, 5, 6, 6,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
1, 1, 1, 1, 1, 2, 2, 2, 2, 4, 4, 4, 5, 5, 6, 6
};
static const int8_t index_table6[] = {
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2,
2, 2, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 6, 6,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2,
2, 2, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 6, 6
};
static const int8_t *const step_index_tables[] = {
index_table1, index_table2, index_table3,
index_table4, index_table5, index_table6
};
static av_cold void predict_table_init(void)
{
for (int start_pos = 0; start_pos < 64; start_pos++) {
unsigned int dest_pos, table_pos;
for (table_pos = 0, dest_pos = start_pos;
table_pos < FF_ARRAY_ELEMS(ff_adpcm_step_table);
table_pos++, dest_pos += 64) {
int put = 0, count, table_value;
table_value = ff_adpcm_step_table[table_pos];
for (count = 32; count != 0; count >>= 1) {
if (start_pos & count)
put += table_value;
table_value >>= 1;
}
predict_table[dest_pos] = put;
}
}
}
static av_cold int decode_init(AVCodecContext *avctx)
{
static AVOnce init_static_once = AV_ONCE_INIT;
avctx->sample_fmt = AV_SAMPLE_FMT_S16;
ff_thread_once(&init_static_once, predict_table_init);
return 0;
}
static int decode_frame(AVCodecContext *avctx, void *data,
int *got_frame_ptr, AVPacket *pkt)
{
GetBitContext gb;
AVFrame *frame = data;
int16_t pcm_data[2];
uint32_t samples;
int8_t channel_hint[2];
int ret, chan;
int channels = 1;
if (pkt->size < 13)
return AVERROR_INVALIDDATA;
if ((ret = init_get_bits8(&gb, pkt->data, pkt->size)) < 0)
return ret;
samples = get_bits_long(&gb, 32);
if (samples == 0xffffffff) {
skip_bits_long(&gb, 32);
samples = get_bits_long(&gb, 32);
}
if (samples > pkt->size * 2)
return AVERROR_INVALIDDATA;
channel_hint[0] = get_sbits(&gb, 8);
if (channel_hint[0] & 0x80) {
channel_hint[0] = ~channel_hint[0];
channels = 2;
}
av_channel_layout_uninit(&avctx->ch_layout);
av_channel_layout_default(&avctx->ch_layout, channels);
pcm_data[0] = get_sbits(&gb, 16);
if (channels > 1) {
channel_hint[1] = get_sbits(&gb, 8);
pcm_data[1] = get_sbits(&gb, 16);
}
frame->nb_samples = samples;
if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
return ret;
for (chan = 0; chan < channels; chan++) {
uint16_t *dest = (uint16_t *)frame->data[0] + chan;
int step_index = channel_hint[chan];
int output = pcm_data[chan];
int sample;
for (sample = 0; sample < samples; sample++) {
int lookup_size, lookup, highbit, lowbits;
step_index = av_clip(step_index, 0, 88);
lookup_size = size_table[step_index];
lookup = get_bits(&gb, lookup_size);
highbit = 1 << (lookup_size - 1);
lowbits = highbit - 1;
if (lookup & highbit)
lookup ^= highbit;
else
highbit = 0;
if (lookup == lowbits) {
output = get_sbits(&gb, 16);
} else {
int predict_index, diff;
predict_index = (lookup << (7 - lookup_size)) | (step_index << 6);
predict_index = av_clip(predict_index, 0, 5785);
diff = predict_table[predict_index];
if (lookup)
diff += ff_adpcm_step_table[step_index] >> (lookup_size - 1);
if (highbit)
diff = -diff;
output = av_clip_int16(output + diff);
}
*dest = output;
dest += channels;
step_index += step_index_tables[lookup_size - 2][lookup];
}
}
*got_frame_ptr = 1;
return pkt->size;
}
const FFCodec ff_adpcm_vima_decoder = {
.p.name = "adpcm_vima",
.p.long_name = NULL_IF_CONFIG_SMALL("LucasArts VIMA audio"),
.p.type = AVMEDIA_TYPE_AUDIO,
.p.id = AV_CODEC_ID_ADPCM_VIMA,
.init = decode_init,
.decode = decode_frame,
.p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_CHANNEL_CONF,
.caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
};