mirror of
https://git.ffmpeg.org/ffmpeg.git
synced 2024-09-21 13:56:55 +00:00
4cfb0d871d
It turns out that the reference decoder subtracts 128 from DC during block decode but adds it back during reordering block with zigzag pattern. Transforming block with incorrect DC caused heavy visual artifacts for many quantisers.
383 lines
12 KiB
C
383 lines
12 KiB
C
/*
|
|
* TechSmith Screen Codec 2 (aka Dora) decoder
|
|
* Copyright (c) 2012 Konstantin Shishkov
|
|
*
|
|
* This file is part of Libav.
|
|
*
|
|
* Libav 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.
|
|
*
|
|
* Libav 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 Libav; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*/
|
|
|
|
/**
|
|
* @file
|
|
* TechSmith Screen Codec 2 decoder
|
|
*/
|
|
|
|
#define BITSTREAM_READER_LE
|
|
#include "avcodec.h"
|
|
#include "get_bits.h"
|
|
#include "bytestream.h"
|
|
#include "tscc2data.h"
|
|
|
|
typedef struct TSCC2Context {
|
|
AVCodecContext *avctx;
|
|
AVFrame pic;
|
|
int mb_width, mb_height;
|
|
uint8_t *slice_quants;
|
|
int quant[2];
|
|
int q[2][3];
|
|
GetBitContext gb;
|
|
|
|
VLC dc_vlc, nc_vlc[NUM_VLC_SETS], ac_vlc[NUM_VLC_SETS];
|
|
int block[16];
|
|
} TSCC2Context;
|
|
|
|
static av_cold void free_vlcs(TSCC2Context *c)
|
|
{
|
|
int i;
|
|
|
|
ff_free_vlc(&c->dc_vlc);
|
|
for (i = 0; i < NUM_VLC_SETS; i++) {
|
|
ff_free_vlc(c->nc_vlc + i);
|
|
ff_free_vlc(c->ac_vlc + i);
|
|
}
|
|
}
|
|
|
|
static av_cold int init_vlcs(TSCC2Context *c)
|
|
{
|
|
int i, ret;
|
|
|
|
ret = ff_init_vlc_sparse(&c->dc_vlc, 9, DC_VLC_COUNT,
|
|
tscc2_dc_vlc_bits, 1, 1,
|
|
tscc2_dc_vlc_codes, 2, 2,
|
|
tscc2_dc_vlc_syms, 2, 2, INIT_VLC_LE);
|
|
if (ret)
|
|
return ret;
|
|
|
|
for (i = 0; i < NUM_VLC_SETS; i++) {
|
|
ret = ff_init_vlc_sparse(c->nc_vlc + i, 9, 16,
|
|
tscc2_nc_vlc_bits[i], 1, 1,
|
|
tscc2_nc_vlc_codes[i], 2, 2,
|
|
tscc2_nc_vlc_syms, 1, 1, INIT_VLC_LE);
|
|
if (ret) {
|
|
free_vlcs(c);
|
|
return ret;
|
|
}
|
|
ret = ff_init_vlc_sparse(c->ac_vlc + i, 9, tscc2_ac_vlc_sizes[i],
|
|
tscc2_ac_vlc_bits[i], 1, 1,
|
|
tscc2_ac_vlc_codes[i], 2, 2,
|
|
tscc2_ac_vlc_syms[i], 2, 2, INIT_VLC_LE);
|
|
if (ret) {
|
|
free_vlcs(c);
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
#define DEQUANT(val, q) ((q * val + 0x80) >> 8)
|
|
#define DCT1D(d0, d1, d2, d3, s0, s1, s2, s3, OP) \
|
|
OP(d0, 5 * ((s0) + (s1) + (s2)) + 2 * (s3)); \
|
|
OP(d1, 5 * ((s0) - (s2) - (s3)) + 2 * (s1)); \
|
|
OP(d2, 5 * ((s0) - (s2) + (s3)) - 2 * (s1)); \
|
|
OP(d3, 5 * ((s0) - (s1) + (s2)) - 2 * (s3)); \
|
|
|
|
#define COL_OP(a, b) a = b
|
|
#define ROW_OP(a, b) a = ((b) + 0x20) >> 6
|
|
|
|
static void tscc2_idct4_put(int *in, int q[3], uint8_t *dst, int stride)
|
|
{
|
|
int i;
|
|
int tblk[4 * 4];
|
|
int t0, t1, t2, t3;
|
|
|
|
for (i = 0; i < 4; i++) {
|
|
t0 = DEQUANT(q[0 + (i & 1)], in[0 * 4 + i]);
|
|
t1 = DEQUANT(q[1 + (i & 1)], in[1 * 4 + i]);
|
|
t2 = DEQUANT(q[0 + (i & 1)], in[2 * 4 + i]);
|
|
t3 = DEQUANT(q[1 + (i & 1)], in[3 * 4 + i]);
|
|
DCT1D(tblk[0 * 4 + i], tblk[1 * 4 + i],
|
|
tblk[2 * 4 + i], tblk[3 * 4 + i],
|
|
t0, t1, t2, t3, COL_OP);
|
|
}
|
|
for (i = 0; i < 4; i++) {
|
|
DCT1D(dst[0], dst[1], dst[2], dst[3],
|
|
tblk[i * 4 + 0], tblk[i * 4 + 1],
|
|
tblk[i * 4 + 2], tblk[i * 4 + 3], ROW_OP);
|
|
dst += stride;
|
|
}
|
|
}
|
|
|
|
static int tscc2_decode_mb(TSCC2Context *c, int *q, int vlc_set,
|
|
uint8_t *dst, int stride, int plane)
|
|
{
|
|
GetBitContext *gb = &c->gb;
|
|
int prev_dc, dc, nc, ac, bpos, val;
|
|
int i, j, k, l;
|
|
|
|
if (get_bits1(gb)) {
|
|
if (get_bits1(gb)) {
|
|
val = get_bits(gb, 8);
|
|
for (i = 0; i < 8; i++, dst += stride)
|
|
memset(dst, val, 16);
|
|
} else {
|
|
if (get_bits_left(gb) < 16 * 8 * 8)
|
|
return AVERROR_INVALIDDATA;
|
|
for (i = 0; i < 8; i++) {
|
|
for (j = 0; j < 16; j++)
|
|
dst[j] = get_bits(gb, 8);
|
|
dst += stride;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
prev_dc = 0;
|
|
for (j = 0; j < 2; j++) {
|
|
for (k = 0; k < 4; k++) {
|
|
if (!(j | k)) {
|
|
dc = get_bits(gb, 8);
|
|
} else {
|
|
dc = get_vlc2(gb, c->dc_vlc.table, 9, 2);
|
|
if (dc == -1)
|
|
return AVERROR_INVALIDDATA;
|
|
if (dc == 0x100)
|
|
dc = get_bits(gb, 8);
|
|
}
|
|
dc = (dc + prev_dc) & 0xFF;
|
|
prev_dc = dc;
|
|
c->block[0] = dc;
|
|
|
|
nc = get_vlc2(gb, c->nc_vlc[vlc_set].table, 9, 1);
|
|
if (nc == -1)
|
|
return AVERROR_INVALIDDATA;
|
|
|
|
bpos = 1;
|
|
memset(c->block + 1, 0, 15 * sizeof(*c->block));
|
|
for (l = 0; l < nc; l++) {
|
|
ac = get_vlc2(gb, c->ac_vlc[vlc_set].table, 9, 2);
|
|
if (ac == -1)
|
|
return AVERROR_INVALIDDATA;
|
|
if (ac == 0x1000)
|
|
ac = get_bits(gb, 12);
|
|
bpos += ac & 0xF;
|
|
if (bpos >= 64)
|
|
return AVERROR_INVALIDDATA;
|
|
val = sign_extend(ac >> 4, 8);
|
|
c->block[tscc2_zigzag[bpos++]] = val;
|
|
}
|
|
tscc2_idct4_put(c->block, q, dst + k * 4, stride);
|
|
}
|
|
dst += 4 * stride;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int tscc2_decode_slice(TSCC2Context *c, int mb_y,
|
|
const uint8_t *buf, int buf_size)
|
|
{
|
|
int i, mb_x, q, ret;
|
|
int off;
|
|
|
|
init_get_bits(&c->gb, buf, buf_size * 8);
|
|
|
|
for (mb_x = 0; mb_x < c->mb_width; mb_x++) {
|
|
q = c->slice_quants[mb_x + c->mb_width * mb_y];
|
|
|
|
if (q == 0 || q == 3) // skip block
|
|
continue;
|
|
for (i = 0; i < 3; i++) {
|
|
off = mb_x * 16 + mb_y * 8 * c->pic.linesize[i];
|
|
ret = tscc2_decode_mb(c, c->q[q - 1], c->quant[q - 1] - 2,
|
|
c->pic.data[i] + off, c->pic.linesize[i], i);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int tscc2_decode_frame(AVCodecContext *avctx, void *data,
|
|
int *data_size, AVPacket *avpkt)
|
|
{
|
|
const uint8_t *buf = avpkt->data;
|
|
int buf_size = avpkt->size;
|
|
TSCC2Context *c = avctx->priv_data;
|
|
GetByteContext gb;
|
|
uint32_t frame_type, size;
|
|
int i, val, len, pos = 0;
|
|
int num_mb = c->mb_width * c->mb_height;
|
|
int ret;
|
|
|
|
bytestream2_init(&gb, buf, buf_size);
|
|
frame_type = bytestream2_get_byte(&gb);
|
|
if (frame_type > 1) {
|
|
av_log(avctx, AV_LOG_ERROR, "Incorrect frame type %d\n", frame_type);
|
|
return AVERROR_INVALIDDATA;
|
|
}
|
|
|
|
c->pic.reference = 3;
|
|
c->pic.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE |
|
|
FF_BUFFER_HINTS_REUSABLE;
|
|
if ((ret = avctx->reget_buffer(avctx, &c->pic)) < 0) {
|
|
av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
|
|
return ret;
|
|
}
|
|
|
|
if (frame_type == 0) {
|
|
*data_size = sizeof(AVFrame);
|
|
*(AVFrame*)data = c->pic;
|
|
|
|
return buf_size;
|
|
}
|
|
|
|
if (bytestream2_get_bytes_left(&gb) < 4) {
|
|
av_log(avctx, AV_LOG_ERROR, "Frame is too short\n");
|
|
return AVERROR_INVALIDDATA;
|
|
}
|
|
|
|
c->quant[0] = bytestream2_get_byte(&gb);
|
|
c->quant[1] = bytestream2_get_byte(&gb);
|
|
if (c->quant[0] < 2 || c->quant[0] > NUM_VLC_SETS + 1 ||
|
|
c->quant[1] < 2 || c->quant[1] > NUM_VLC_SETS + 1) {
|
|
av_log(avctx, AV_LOG_ERROR, "Invalid quantisers %d / %d\n",
|
|
c->quant[0], c->quant[1]);
|
|
return AVERROR_INVALIDDATA;
|
|
}
|
|
|
|
for (i = 0; i < 3; i++) {
|
|
c->q[0][i] = tscc2_quants[c->quant[0] - 2][i];
|
|
c->q[1][i] = tscc2_quants[c->quant[1] - 2][i];
|
|
}
|
|
|
|
bytestream2_skip(&gb, 1);
|
|
|
|
size = bytestream2_get_le32(&gb);
|
|
if (size > bytestream2_get_bytes_left(&gb)) {
|
|
av_log(avctx, AV_LOG_ERROR, "Slice properties chunk is too large\n");
|
|
return AVERROR_INVALIDDATA;
|
|
}
|
|
|
|
for (i = 0; i < size; i++) {
|
|
val = bytestream2_get_byte(&gb);
|
|
len = val & 0x3F;
|
|
val >>= 6;
|
|
if (pos + len > num_mb) {
|
|
av_log(avctx, AV_LOG_ERROR, "Too many slice properties\n");
|
|
return AVERROR_INVALIDDATA;
|
|
}
|
|
memset(c->slice_quants + pos, val, len);
|
|
pos += len;
|
|
}
|
|
if (pos < num_mb) {
|
|
av_log(avctx, AV_LOG_ERROR, "Too few slice properties (%d / %d)\n",
|
|
pos, num_mb);
|
|
return AVERROR_INVALIDDATA;
|
|
}
|
|
|
|
for (i = 0; i < c->mb_height; i++) {
|
|
size = bytestream2_peek_byte(&gb);
|
|
if (size & 1) {
|
|
size = bytestream2_get_byte(&gb) - 1;
|
|
} else {
|
|
size = bytestream2_get_le32(&gb) >> 1;
|
|
}
|
|
if (!size) {
|
|
int skip_row = 1, j, off = i * c->mb_width;
|
|
for (j = 0; j < c->mb_width; j++) {
|
|
if (c->slice_quants[off + i] == 1 ||
|
|
c->slice_quants[off + i] == 2) {
|
|
skip_row = 0;
|
|
break;
|
|
}
|
|
}
|
|
if (!skip_row) {
|
|
av_log(avctx, AV_LOG_ERROR, "Non-skip row with zero size\n");
|
|
return AVERROR_INVALIDDATA;
|
|
}
|
|
}
|
|
if (bytestream2_get_bytes_left(&gb) < size) {
|
|
av_log(avctx, AV_LOG_ERROR, "Invalid slice size (%d/%d)\n",
|
|
size, bytestream2_get_bytes_left(&gb));
|
|
return AVERROR_INVALIDDATA;
|
|
}
|
|
ret = tscc2_decode_slice(c, i, buf + bytestream2_tell(&gb), size);
|
|
if (ret) {
|
|
av_log(avctx, AV_LOG_ERROR, "Error decoding slice %d\n", i);
|
|
return ret;
|
|
}
|
|
bytestream2_skip(&gb, size);
|
|
}
|
|
|
|
*data_size = sizeof(AVFrame);
|
|
*(AVFrame*)data = c->pic;
|
|
|
|
/* always report that the buffer was completely consumed */
|
|
return buf_size;
|
|
}
|
|
|
|
static av_cold int tscc2_decode_init(AVCodecContext *avctx)
|
|
{
|
|
TSCC2Context * const c = avctx->priv_data;
|
|
int ret;
|
|
|
|
c->avctx = avctx;
|
|
|
|
avctx->pix_fmt = PIX_FMT_YUV444P;
|
|
|
|
if ((ret = init_vlcs(c)) < 0) {
|
|
av_log(avctx, AV_LOG_ERROR, "Cannot initialise VLCs\n");
|
|
return ret;
|
|
}
|
|
|
|
c->mb_width = FFALIGN(avctx->width, 16) >> 4;
|
|
c->mb_height = FFALIGN(avctx->height, 8) >> 3;
|
|
c->slice_quants = av_malloc(c->mb_width * c->mb_height);
|
|
if (!c->slice_quants) {
|
|
av_log(avctx, AV_LOG_ERROR, "Cannot allocate slice information\n");
|
|
free_vlcs(c);
|
|
return AVERROR(ENOMEM);
|
|
}
|
|
|
|
avctx->coded_frame = &c->pic;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static av_cold int tscc2_decode_end(AVCodecContext *avctx)
|
|
{
|
|
TSCC2Context * const c = avctx->priv_data;
|
|
|
|
if (c->pic.data[0])
|
|
avctx->release_buffer(avctx, &c->pic);
|
|
av_freep(&c->slice_quants);
|
|
free_vlcs(c);
|
|
|
|
return 0;
|
|
}
|
|
|
|
AVCodec ff_tscc2_decoder = {
|
|
.name = "tscc2",
|
|
.type = AVMEDIA_TYPE_VIDEO,
|
|
.id = CODEC_ID_TSCC2,
|
|
.priv_data_size = sizeof(TSCC2Context),
|
|
.init = tscc2_decode_init,
|
|
.close = tscc2_decode_end,
|
|
.decode = tscc2_decode_frame,
|
|
.capabilities = CODEC_CAP_DR1,
|
|
.long_name = NULL_IF_CONFIG_SMALL("TechSmith Screen Codec 2"),
|
|
};
|