/*
* Gremlin Digital Video (GDV) decoder
* Copyright (c) 2017 Konstantin Shishkov
* Copyright (c) 2017 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
*/
#include "libavutil/common.h"
#include "avcodec.h"
#include "bytestream.h"
#include "internal.h"
typedef struct GDVContext {
AVCodecContext *avctx;
GetByteContext gb;
GetByteContext g2;
PutByteContext pb;
uint32_t pal[256];
uint8_t *frame;
unsigned frame_size;
unsigned scale_h, scale_v;
} GDVContext;
typedef struct Bits8 {
uint8_t queue;
uint8_t fill;
} Bits8;
typedef struct Bits32 {
uint32_t queue;
uint8_t fill;
} Bits32;
#define PREAMBLE_SIZE 4096
static av_cold int gdv_decode_init(AVCodecContext *avctx)
{
GDVContext *gdv = avctx->priv_data;
int i, j, k;
avctx->pix_fmt = AV_PIX_FMT_PAL8;
gdv->frame_size = avctx->width * avctx->height + PREAMBLE_SIZE;
gdv->frame = av_calloc(gdv->frame_size, 1);
if (!gdv->frame)
return AVERROR(ENOMEM);
for (i = 0; i < 2; i++) {
for (j = 0; j < 256; j++) {
for (k = 0; k < 8; k++) {
gdv->frame[i * 2048 + j * 8 + k] = j;
}
}
}
return 0;
}
static void scaleup(uint8_t *dst, const uint8_t *src, int w)
{
int x;
for (x = 0; x < w - 7; x+=8) {
dst[x + 0] =
dst[x + 1] = src[(x>>1) + 0];
dst[x + 2] =
dst[x + 3] = src[(x>>1) + 1];
dst[x + 4] =
dst[x + 5] = src[(x>>1) + 2];
dst[x + 6] =
dst[x + 7] = src[(x>>1) + 3];
}
for (; x < w; x++) {
dst[x] = src[(x>>1)];
}
}
static void scaleup_rev(uint8_t *dst, const uint8_t *src, int w)
{
int x;
for (x = w - 1; (x+1) & 7; x--) {
dst[x] = src[(x>>1)];
}
for (x -= 7; x >= 0; x -= 8) {
dst[x + 6] =
dst[x + 7] = src[(x>>1) + 3];
dst[x + 4] =
dst[x + 5] = src[(x>>1) + 2];
dst[x + 2] =
dst[x + 3] = src[(x>>1) + 1];
dst[x + 0] =
dst[x + 1] = src[(x>>1) + 0];
}
}
static void scaledown(uint8_t *dst, const uint8_t *src, int w)
{
int x;
for (x = 0; x < w - 7; x+=8) {
dst[x + 0] = src[2*x + 0];
dst[x + 1] = src[2*x + 2];
dst[x + 2] = src[2*x + 4];
dst[x + 3] = src[2*x + 6];
dst[x + 4] = src[2*x + 8];
dst[x + 5] = src[2*x +10];
dst[x + 6] = src[2*x +12];
dst[x + 7] = src[2*x +14];
}
for (; x < w; x++) {
dst[x] = src[2*x];
}
}
static void rescale(GDVContext *gdv, uint8_t *dst, int w, int h, int scale_v, int scale_h)
{
int j, y;
if ((gdv->scale_v == scale_v) && (gdv->scale_h == scale_h)) {
return;
}
if (gdv->scale_v) {
for (j = 0; j < h; j++) {
int y = h - j - 1;
uint8_t *dst1 = dst + PREAMBLE_SIZE + y * w;
uint8_t *src1 = dst + PREAMBLE_SIZE + (y>>!!gdv->scale_h) * (w>>1);
scaleup_rev(dst1, src1, w);
}
} else if (gdv->scale_h) {
for (j = 0; j < h; j++) {
int y = h - j - 1;
uint8_t *dst1 = dst + PREAMBLE_SIZE + y * w;
uint8_t *src1 = dst + PREAMBLE_SIZE + (y>>1) * w;
memcpy(dst1, src1, w);
}
}
if (scale_h && scale_v) {
for (y = 0; y < (h>>1); y++) {
uint8_t *dst1 = dst + PREAMBLE_SIZE + y * (w>>1);
uint8_t *src1 = dst + PREAMBLE_SIZE + y*2 * w;
scaledown(dst1, src1, w>>1);
}
} else if (scale_h) {
for (y = 0; y < (h>>1); y++) {
uint8_t *dst1 = dst + PREAMBLE_SIZE + y * w;
uint8_t *src1 = dst + PREAMBLE_SIZE + y*2 * w;
memcpy(dst1, src1, w);
}
} else if (scale_v) {
for (y = 0; y < h; y++) {
uint8_t *dst1 = dst + PREAMBLE_SIZE + y * w;
scaledown(dst1, dst1, w>>1);
}
}
gdv->scale_v = scale_v;
gdv->scale_h = scale_h;
}
static int read_bits2(Bits8 *bits, GetByteContext *gb)
{
int res;
if (bits->fill == 0) {
bits->queue |= bytestream2_get_byte(gb);
bits->fill = 8;
}
res = bits->queue >> 6;
bits->queue <<= 2;
bits->fill -= 2;
return res;
}
static void fill_bits32(Bits32 *bits, GetByteContext *gb)
{
bits->queue = bytestream2_get_le32(gb);
bits->fill = 32;
}
static int read_bits32(Bits32 *bits, GetByteContext *gb, int nbits)
{
int res = bits->queue & ((1 << nbits) - 1);
bits->queue >>= nbits;
bits->fill -= nbits;
if (bits->fill <= 16) {
bits->queue |= bytestream2_get_le16(gb) << bits->fill;
bits->fill += 16;
}
return res;
}
static void lz_copy(PutByteContext *pb, GetByteContext *g2, int offset, unsigned len)
{
int i;
if (offset == -1) {
int c;
bytestream2_seek(g2, bytestream2_tell_p(pb) - 1, SEEK_SET);
c = bytestream2_get_byte(g2);
for (i = 0; i < len; i++) {
bytestream2_put_byte(pb, c);
}
} else if (offset < 0) {
int start = bytestream2_tell_p(pb) - (-offset);
bytestream2_seek(g2, start, SEEK_SET);
for (i = 0; i < len; i++) {
bytestream2_put_byte(pb, bytestream2_get_byte(g2));
}
} else {
int start = bytestream2_tell_p(pb) + offset;
bytestream2_seek(g2, start, SEEK_SET);
for (i = 0; i < len; i++) {
bytestream2_put_byte(pb, bytestream2_get_byte(g2));
}
}
}
static int decompress_2(AVCodecContext *avctx)
{
GDVContext *gdv = avctx->priv_data;
GetByteContext *gb = &gdv->gb;
GetByteContext *g2 = &gdv->g2;
PutByteContext *pb = &gdv->pb;
Bits8 bits = { 0 };
int c, i;
bytestream2_init(g2, gdv->frame, gdv->frame_size);
bytestream2_skip_p(pb, PREAMBLE_SIZE);
for (c = 0; c < 256; c++) {
for (i = 0; i < 16; i++) {
gdv->frame[c * 16 + i] = c;
}
}
while (bytestream2_get_bytes_left_p(pb) > 0 && bytestream2_get_bytes_left(gb) > 0) {
int tag = read_bits2(&bits, gb);
if (tag == 0) {
bytestream2_put_byte(pb, bytestream2_get_byte(gb));
} else if (tag == 1) {
int b = bytestream2_get_byte(gb);
int len = (b & 0xF) + 3;
int top = (b >> 4) & 0xF;
int off = (bytestream2_get_byte(gb) << 4) + top - 4096;
lz_copy(pb, g2, off, len);
} else if (tag == 2) {
int len = (bytestream2_get_byte(gb)) + 2;
bytestream2_skip_p(pb, len);
} else {
break;
}
}
if (bytestream2_get_bytes_left_p(pb) > 0)
return AVERROR_INVALIDDATA;
return 0;
}
static int decompress_5(AVCodecContext *avctx, unsigned skip)
{
GDVContext *gdv = avctx->priv_data;
GetByteContext *gb = &gdv->gb;
GetByteContext *g2 = &gdv->g2;
PutByteContext *pb = &gdv->pb;
Bits8 bits = { 0 };
bytestream2_init(g2, gdv->frame, gdv->frame_size);
bytestream2_skip_p(pb, skip + PREAMBLE_SIZE);
while (bytestream2_get_bytes_left_p(pb) > 0 && bytestream2_get_bytes_left(gb) > 0) {
int tag = read_bits2(&bits, gb);
if (bytestream2_get_bytes_left(gb) < 1)
return AVERROR_INVALIDDATA;
if (tag == 0) {
bytestream2_put_byte(pb, bytestream2_get_byte(gb));
} else if (tag == 1) {
int b = bytestream2_get_byte(gb);
int len = (b & 0xF) + 3;
int top = b >> 4;
int off = (bytestream2_get_byte(gb) << 4) + top - 4096;
lz_copy(pb, g2, off, len);
} else if (tag == 2) {
int len;
int b = bytestream2_get_byte(gb);
if (b == 0) {
return 0;
}
if (b != 0xFF) {
len = b;
} else {
len = bytestream2_get_le16(gb);
}
bytestream2_skip_p(pb, len + 1);
} else {
int b = bytestream2_get_byte(gb);
int len = (b & 0x3) + 2;
int off = -(b >> 2) - 1;
lz_copy(pb, g2, off, len);
}
}
if (bytestream2_get_bytes_left_p(pb) > 0)
return AVERROR_INVALIDDATA;
return 0;
}
static int decompress_68(AVCodecContext *avctx, unsigned skip, unsigned use8)
{
GDVContext *gdv = avctx->priv_data;
GetByteContext *gb = &gdv->gb;
GetByteContext *g2 = &gdv->g2;
PutByteContext *pb = &gdv->pb;
Bits32 bits;
bytestream2_init(g2, gdv->frame, gdv->frame_size);
bytestream2_skip_p(pb, skip + PREAMBLE_SIZE);
fill_bits32(&bits, gb);
while (bytestream2_get_bytes_left_p(pb) > 0 && bytestream2_get_bytes_left(gb) > 0) {
int tag = read_bits32(&bits, gb, 2);
if (tag == 0) {
int b = read_bits32(&bits, gb, 1);
if (b == 0) {
bytestream2_put_byte(pb, bytestream2_get_byte(gb));
} else {
int i, len = 2;
int lbits = 0;
while (1) {
int val;
lbits += 1;
val = read_bits32(&bits, gb, lbits);
len += val;
if (val != ((1 << lbits) - 1)) {
break;
}
if (lbits >= 16)
return AVERROR_INVALIDDATA;
}
for (i = 0; i < len; i++) {
bytestream2_put_byte(pb, bytestream2_get_byte(gb));
}
}
} else if (tag == 1) {
int b = read_bits32(&bits, gb, 1);
int len;
if (b == 0) {
len = (read_bits32(&bits, gb, 4)) + 2;
} else {
int bb = bytestream2_get_byte(gb);
if ((bb & 0x80) == 0) {
len = bb + 18;
} else {
int top = (bb & 0x7F) << 8;
len = top + bytestream2_get_byte(gb) + 146;
}
}
bytestream2_skip_p(pb, len);
} else if (tag == 2) {
int i, subtag = read_bits32(&bits, gb, 2);
if (subtag != 3) {
int top = (read_bits32(&bits, gb, 4)) << 8;
int offs = top + bytestream2_get_byte(gb);
if ((subtag != 0) || (offs <= 0xF80)) {
int len = (subtag) + 3;
lz_copy(pb, g2, (offs) - 4096, len);
} else {
int real_off, len, c1, c2;
if (offs == 0xFFF) {
return 0;
}
real_off = ((offs >> 4) & 0x7) + 1;
len = ((offs & 0xF) + 2) * 2;
c1 = gdv->frame[bytestream2_tell_p(pb) - real_off];
c2 = gdv->frame[bytestream2_tell_p(pb) - real_off + 1];
for (i = 0; i < len/2; i++) {
bytestream2_put_byte(pb, c1);
bytestream2_put_byte(pb, c2);
}
}
} else {
int b = bytestream2_get_byte(gb);
int off = ((b & 0x7F)) + 1;
int len = ((b & 0x80) == 0) ? 2 : 3;
lz_copy(pb, g2, -off, len);
}
} else {
int len;
int off;
if (use8) {
int q, b = bytestream2_get_byte(gb);
if ((b & 0xC0) == 0xC0) {
len = ((b & 0x3F)) + 8;
q = read_bits32(&bits, gb, 4);
off = (q << 8) + (bytestream2_get_byte(gb)) + 1;
} else {
int ofs1;
if ((b & 0x80) == 0) {
len = ((b >> 4)) + 6;
ofs1 = (b & 0xF);
} else {
len = ((b & 0x3F)) + 14;
ofs1 = read_bits32(&bits, gb, 4);
}
off = (ofs1 << 8) + (bytestream2_get_byte(gb)) - 4096;
}
} else {
int ofs1, b = bytestream2_get_byte(gb);
if ((b >> 4) == 0xF) {
len = bytestream2_get_byte(gb) + 21;
} else {
len = (b >> 4) + 6;
}
ofs1 = (b & 0xF);
off = (ofs1 << 8) + bytestream2_get_byte(gb) - 4096;
}
lz_copy(pb, g2, off, len);
}
}
if (bytestream2_get_bytes_left_p(pb) > 0)
return AVERROR_INVALIDDATA;
return 0;
}
static int gdv_decode_frame(AVCodecContext *avctx, void *data,
int *got_frame, AVPacket *avpkt)
{
GDVContext *gdv = avctx->priv_data;
GetByteContext *gb = &gdv->gb;
PutByteContext *pb = &gdv->pb;
AVFrame *frame = data;
int ret, i, pal_size;
const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, &pal_size);
int compression;
unsigned flags;
uint8_t *dst;
bytestream2_init(gb, avpkt->data, avpkt->size);
bytestream2_init_writer(pb, gdv->frame, gdv->frame_size);
flags = bytestream2_get_le32(gb);
compression = flags & 0xF;
if (compression == 4 || compression == 7 || compression > 8)
return AVERROR_INVALIDDATA;
if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
return ret;
if (pal && pal_size == AVPALETTE_SIZE)
memcpy(gdv->pal, pal, AVPALETTE_SIZE);
if (compression < 2 && bytestream2_get_bytes_left(gb) < 256*3)
return AVERROR_INVALIDDATA;
rescale(gdv, gdv->frame, avctx->width, avctx->height,
!!(flags & 0x10), !!(flags & 0x20));
switch (compression) {
case 1:
memset(gdv->frame + PREAMBLE_SIZE, 0, gdv->frame_size - PREAMBLE_SIZE);
case 0:
for (i = 0; i < 256; i++) {
unsigned r = bytestream2_get_byte(gb);
unsigned g = bytestream2_get_byte(gb);
unsigned b = bytestream2_get_byte(gb);
gdv->pal[i] = 0xFFU << 24 | r << 18 | g << 10 | b << 2;
}
break;
case 2:
ret = decompress_2(avctx);
break;
case 3:
break;
case 5:
ret = decompress_5(avctx, flags >> 8);
break;
case 6:
ret = decompress_68(avctx, flags >> 8, 0);
break;
case 8:
ret = decompress_68(avctx, flags >> 8, 1);
break;
default:
av_assert0(0);
}
if (ret < 0)
return ret;
memcpy(frame->data[1], gdv->pal, AVPALETTE_SIZE);
dst = frame->data[0];
if (!gdv->scale_v && !gdv->scale_h) {
int sidx = PREAMBLE_SIZE, didx = 0;
int y;
for (y = 0; y < avctx->height; y++) {
memcpy(dst + didx, gdv->frame + sidx, avctx->width);
sidx += avctx->width;
didx += frame->linesize[0];
}
} else {
int sidx = PREAMBLE_SIZE, didx = 0;
int y;
for (y = 0; y < avctx->height; y++) {
if (!gdv->scale_v) {
memcpy(dst + didx, gdv->frame + sidx, avctx->width);
} else {
uint8_t *dst2 = dst + didx;
uint8_t *src2 = gdv->frame + sidx;
scaleup(dst2, src2, avctx->width);
}
if (!gdv->scale_h || ((y & 1) == 1)) {
sidx += !gdv->scale_v ? avctx->width : avctx->width/2;
}
didx += frame->linesize[0];
}
}
*got_frame = 1;
return ret < 0 ? ret : avpkt->size;
}
static av_cold int gdv_decode_close(AVCodecContext *avctx)
{
GDVContext *gdv = avctx->priv_data;
av_freep(&gdv->frame);
return 0;
}
AVCodec ff_gdv_decoder = {
.name = "gdv",
.long_name = NULL_IF_CONFIG_SMALL("Gremlin Digital Video"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_GDV,
.priv_data_size = sizeof(GDVContext),
.init = gdv_decode_init,
.close = gdv_decode_close,
.decode = gdv_decode_frame,
.capabilities = AV_CODEC_CAP_DR1,
.caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
};