mirror of https://git.ffmpeg.org/ffmpeg.git
385 lines
12 KiB
C
385 lines
12 KiB
C
/*
|
|
* CD Graphics Video Decoder
|
|
* Copyright (c) 2009 Michael Tison
|
|
*
|
|
* 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 "avcodec.h"
|
|
#include "bytestream.h"
|
|
|
|
/**
|
|
* @file
|
|
* @brief CD Graphics Video Decoder
|
|
* @author Michael Tison
|
|
* @see http://wiki.multimedia.cx/index.php?title=CD_Graphics
|
|
* @see http://www.ccs.neu.edu/home/bchafy/cdb/info/cdg
|
|
*/
|
|
|
|
/// default screen sizes
|
|
#define CDG_FULL_WIDTH 300
|
|
#define CDG_FULL_HEIGHT 216
|
|
#define CDG_DISPLAY_WIDTH 294
|
|
#define CDG_DISPLAY_HEIGHT 204
|
|
#define CDG_BORDER_WIDTH 6
|
|
#define CDG_BORDER_HEIGHT 12
|
|
|
|
/// masks
|
|
#define CDG_COMMAND 0x09
|
|
#define CDG_MASK 0x3F
|
|
|
|
/// instruction codes
|
|
#define CDG_INST_MEMORY_PRESET 1
|
|
#define CDG_INST_BORDER_PRESET 2
|
|
#define CDG_INST_TILE_BLOCK 6
|
|
#define CDG_INST_SCROLL_PRESET 20
|
|
#define CDG_INST_SCROLL_COPY 24
|
|
#define CDG_INST_LOAD_PAL_LO 30
|
|
#define CDG_INST_LOAD_PAL_HIGH 31
|
|
#define CDG_INST_TILE_BLOCK_XOR 38
|
|
|
|
/// data sizes
|
|
#define CDG_PACKET_SIZE 24
|
|
#define CDG_DATA_SIZE 16
|
|
#define CDG_TILE_HEIGHT 12
|
|
#define CDG_TILE_WIDTH 6
|
|
#define CDG_MINIMUM_PKT_SIZE 6
|
|
#define CDG_MINIMUM_SCROLL_SIZE 3
|
|
#define CDG_HEADER_SIZE 8
|
|
#define CDG_PALETTE_SIZE 16
|
|
|
|
typedef struct CDGraphicsContext {
|
|
AVFrame frame;
|
|
int hscroll;
|
|
int vscroll;
|
|
} CDGraphicsContext;
|
|
|
|
static void cdg_init_frame(AVFrame *frame)
|
|
{
|
|
avcodec_get_frame_defaults(frame);
|
|
frame->reference = 3;
|
|
frame->buffer_hints = FF_BUFFER_HINTS_VALID |
|
|
FF_BUFFER_HINTS_READABLE |
|
|
FF_BUFFER_HINTS_PRESERVE |
|
|
FF_BUFFER_HINTS_REUSABLE;
|
|
}
|
|
|
|
static av_cold int cdg_decode_init(AVCodecContext *avctx)
|
|
{
|
|
CDGraphicsContext *cc = avctx->priv_data;
|
|
|
|
cdg_init_frame(&cc->frame);
|
|
|
|
avctx->width = CDG_FULL_WIDTH;
|
|
avctx->height = CDG_FULL_HEIGHT;
|
|
avctx->pix_fmt = AV_PIX_FMT_PAL8;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void cdg_border_preset(CDGraphicsContext *cc, uint8_t *data)
|
|
{
|
|
int y;
|
|
int lsize = cc->frame.linesize[0];
|
|
uint8_t *buf = cc->frame.data[0];
|
|
int color = data[0] & 0x0F;
|
|
|
|
if (!(data[1] & 0x0F)) {
|
|
/// fill the top and bottom borders
|
|
memset(buf, color, CDG_BORDER_HEIGHT * lsize);
|
|
memset(buf + (CDG_FULL_HEIGHT - CDG_BORDER_HEIGHT) * lsize,
|
|
color, CDG_BORDER_HEIGHT * lsize);
|
|
|
|
/// fill the side borders
|
|
for (y = CDG_BORDER_HEIGHT; y < CDG_FULL_HEIGHT - CDG_BORDER_HEIGHT; y++) {
|
|
memset(buf + y * lsize, color, CDG_BORDER_WIDTH);
|
|
memset(buf + CDG_FULL_WIDTH - CDG_BORDER_WIDTH + y * lsize,
|
|
color, CDG_BORDER_WIDTH);
|
|
}
|
|
}
|
|
}
|
|
|
|
static void cdg_load_palette(CDGraphicsContext *cc, uint8_t *data, int low)
|
|
{
|
|
uint8_t r, g, b;
|
|
uint16_t color;
|
|
int i;
|
|
int array_offset = low ? 0 : 8;
|
|
uint32_t *palette = (uint32_t *) cc->frame.data[1];
|
|
|
|
for (i = 0; i < 8; i++) {
|
|
color = (data[2 * i] << 6) + (data[2 * i + 1] & 0x3F);
|
|
r = ((color >> 8) & 0x000F) * 17;
|
|
g = ((color >> 4) & 0x000F) * 17;
|
|
b = ((color ) & 0x000F) * 17;
|
|
palette[i + array_offset] = 0xFF << 24 | r << 16 | g << 8 | b;
|
|
}
|
|
cc->frame.palette_has_changed = 1;
|
|
}
|
|
|
|
static int cdg_tile_block(CDGraphicsContext *cc, uint8_t *data, int b)
|
|
{
|
|
unsigned ci, ri;
|
|
int color;
|
|
int x, y;
|
|
int ai;
|
|
int stride = cc->frame.linesize[0];
|
|
uint8_t *buf = cc->frame.data[0];
|
|
|
|
ri = (data[2] & 0x1F) * CDG_TILE_HEIGHT + cc->vscroll;
|
|
ci = (data[3] & 0x3F) * CDG_TILE_WIDTH + cc->hscroll;
|
|
|
|
if (ri > (CDG_FULL_HEIGHT - CDG_TILE_HEIGHT))
|
|
return AVERROR(EINVAL);
|
|
if (ci > (CDG_FULL_WIDTH - CDG_TILE_WIDTH))
|
|
return AVERROR(EINVAL);
|
|
|
|
for (y = 0; y < CDG_TILE_HEIGHT; y++) {
|
|
for (x = 0; x < CDG_TILE_WIDTH; x++) {
|
|
if (!((data[4 + y] >> (5 - x)) & 0x01))
|
|
color = data[0] & 0x0F;
|
|
else
|
|
color = data[1] & 0x0F;
|
|
|
|
ai = ci + x + (stride * (ri + y));
|
|
if (b)
|
|
color ^= buf[ai];
|
|
buf[ai] = color;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
#define UP 2
|
|
#define DOWN 1
|
|
#define LEFT 2
|
|
#define RIGHT 1
|
|
|
|
static void cdg_copy_rect_buf(int out_tl_x, int out_tl_y, uint8_t *out,
|
|
int in_tl_x, int in_tl_y, uint8_t *in,
|
|
int w, int h, int stride)
|
|
{
|
|
int y;
|
|
|
|
in += in_tl_x + in_tl_y * stride;
|
|
out += out_tl_x + out_tl_y * stride;
|
|
for (y = 0; y < h; y++)
|
|
memcpy(out + y * stride, in + y * stride, w);
|
|
}
|
|
|
|
static void cdg_fill_rect_preset(int tl_x, int tl_y, uint8_t *out,
|
|
int color, int w, int h, int stride)
|
|
{
|
|
int y;
|
|
|
|
for (y = tl_y; y < tl_y + h; y++)
|
|
memset(out + tl_x + y * stride, color, w);
|
|
}
|
|
|
|
static void cdg_fill_wrapper(int out_tl_x, int out_tl_y, uint8_t *out,
|
|
int in_tl_x, int in_tl_y, uint8_t *in,
|
|
int color, int w, int h, int stride, int roll)
|
|
{
|
|
if (roll) {
|
|
cdg_copy_rect_buf(out_tl_x, out_tl_y, out, in_tl_x, in_tl_y,
|
|
in, w, h, stride);
|
|
} else {
|
|
cdg_fill_rect_preset(out_tl_x, out_tl_y, out, color, w, h, stride);
|
|
}
|
|
}
|
|
|
|
static void cdg_scroll(CDGraphicsContext *cc, uint8_t *data,
|
|
AVFrame *new_frame, int roll_over)
|
|
{
|
|
int color;
|
|
int hscmd, h_off, hinc, vscmd, v_off, vinc;
|
|
int y;
|
|
int stride = cc->frame.linesize[0];
|
|
uint8_t *in = cc->frame.data[0];
|
|
uint8_t *out = new_frame->data[0];
|
|
|
|
color = data[0] & 0x0F;
|
|
hscmd = (data[1] & 0x30) >> 4;
|
|
vscmd = (data[2] & 0x30) >> 4;
|
|
|
|
h_off = FFMIN(data[1] & 0x07, CDG_BORDER_WIDTH - 1);
|
|
v_off = FFMIN(data[2] & 0x07, CDG_BORDER_HEIGHT - 1);
|
|
|
|
/// find the difference and save the offset for cdg_tile_block usage
|
|
hinc = h_off - cc->hscroll;
|
|
vinc = v_off - cc->vscroll;
|
|
cc->hscroll = h_off;
|
|
cc->vscroll = v_off;
|
|
|
|
if (vscmd == UP)
|
|
vinc -= 12;
|
|
if (vscmd == DOWN)
|
|
vinc += 12;
|
|
if (hscmd == LEFT)
|
|
hinc -= 6;
|
|
if (hscmd == RIGHT)
|
|
hinc += 6;
|
|
|
|
if (!hinc && !vinc)
|
|
return;
|
|
|
|
memcpy(new_frame->data[1], cc->frame.data[1], CDG_PALETTE_SIZE * 4);
|
|
|
|
for (y = FFMAX(0, vinc); y < FFMIN(CDG_FULL_HEIGHT + vinc, CDG_FULL_HEIGHT); y++)
|
|
memcpy(out + FFMAX(0, hinc) + stride * y,
|
|
in + FFMAX(0, hinc) - hinc + (y - vinc) * stride,
|
|
FFMIN(stride + hinc, stride));
|
|
|
|
if (vinc > 0)
|
|
cdg_fill_wrapper(0, 0, out,
|
|
0, CDG_FULL_HEIGHT - vinc, in, color,
|
|
stride, vinc, stride, roll_over);
|
|
else if (vinc < 0)
|
|
cdg_fill_wrapper(0, CDG_FULL_HEIGHT + vinc, out,
|
|
0, 0, in, color,
|
|
stride, -1 * vinc, stride, roll_over);
|
|
|
|
if (hinc > 0)
|
|
cdg_fill_wrapper(0, 0, out,
|
|
CDG_FULL_WIDTH - hinc, 0, in, color,
|
|
hinc, CDG_FULL_HEIGHT, stride, roll_over);
|
|
else if (hinc < 0)
|
|
cdg_fill_wrapper(CDG_FULL_WIDTH + hinc, 0, out,
|
|
0, 0, in, color,
|
|
-1 * hinc, CDG_FULL_HEIGHT, stride, roll_over);
|
|
|
|
}
|
|
|
|
static int cdg_decode_frame(AVCodecContext *avctx,
|
|
void *data, int *data_size, AVPacket *avpkt)
|
|
{
|
|
const uint8_t *buf = avpkt->data;
|
|
int buf_size = avpkt->size;
|
|
int ret;
|
|
uint8_t command, inst;
|
|
uint8_t cdg_data[CDG_DATA_SIZE];
|
|
AVFrame new_frame;
|
|
CDGraphicsContext *cc = avctx->priv_data;
|
|
|
|
if (buf_size < CDG_MINIMUM_PKT_SIZE) {
|
|
av_log(avctx, AV_LOG_ERROR, "buffer too small for decoder\n");
|
|
return AVERROR(EINVAL);
|
|
}
|
|
if (buf_size > CDG_HEADER_SIZE + CDG_DATA_SIZE) {
|
|
av_log(avctx, AV_LOG_ERROR, "buffer too big for decoder\n");
|
|
return AVERROR(EINVAL);
|
|
}
|
|
|
|
ret = avctx->reget_buffer(avctx, &cc->frame);
|
|
if (ret) {
|
|
av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
|
|
return ret;
|
|
}
|
|
|
|
command = bytestream_get_byte(&buf);
|
|
inst = bytestream_get_byte(&buf);
|
|
inst &= CDG_MASK;
|
|
buf += 2; /// skipping 2 unneeded bytes
|
|
bytestream_get_buffer(&buf, cdg_data, buf_size - CDG_HEADER_SIZE);
|
|
|
|
if ((command & CDG_MASK) == CDG_COMMAND) {
|
|
switch (inst) {
|
|
case CDG_INST_MEMORY_PRESET:
|
|
if (!(cdg_data[1] & 0x0F))
|
|
memset(cc->frame.data[0], cdg_data[0] & 0x0F,
|
|
cc->frame.linesize[0] * CDG_FULL_HEIGHT);
|
|
break;
|
|
case CDG_INST_LOAD_PAL_LO:
|
|
case CDG_INST_LOAD_PAL_HIGH:
|
|
if (buf_size - CDG_HEADER_SIZE < CDG_DATA_SIZE) {
|
|
av_log(avctx, AV_LOG_ERROR, "buffer too small for loading palette\n");
|
|
return AVERROR(EINVAL);
|
|
}
|
|
|
|
cdg_load_palette(cc, cdg_data, inst == CDG_INST_LOAD_PAL_LO);
|
|
break;
|
|
case CDG_INST_BORDER_PRESET:
|
|
cdg_border_preset(cc, cdg_data);
|
|
break;
|
|
case CDG_INST_TILE_BLOCK_XOR:
|
|
case CDG_INST_TILE_BLOCK:
|
|
if (buf_size - CDG_HEADER_SIZE < CDG_DATA_SIZE) {
|
|
av_log(avctx, AV_LOG_ERROR, "buffer too small for drawing tile\n");
|
|
return AVERROR(EINVAL);
|
|
}
|
|
|
|
ret = cdg_tile_block(cc, cdg_data, inst == CDG_INST_TILE_BLOCK_XOR);
|
|
if (ret) {
|
|
av_log(avctx, AV_LOG_ERROR, "tile is out of range\n");
|
|
return ret;
|
|
}
|
|
break;
|
|
case CDG_INST_SCROLL_PRESET:
|
|
case CDG_INST_SCROLL_COPY:
|
|
if (buf_size - CDG_HEADER_SIZE < CDG_MINIMUM_SCROLL_SIZE) {
|
|
av_log(avctx, AV_LOG_ERROR, "buffer too small for scrolling\n");
|
|
return AVERROR(EINVAL);
|
|
}
|
|
|
|
cdg_init_frame(&new_frame);
|
|
ret = avctx->get_buffer(avctx, &new_frame);
|
|
if (ret) {
|
|
av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
|
|
return ret;
|
|
}
|
|
|
|
cdg_scroll(cc, cdg_data, &new_frame, inst == CDG_INST_SCROLL_COPY);
|
|
avctx->release_buffer(avctx, &cc->frame);
|
|
cc->frame = new_frame;
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
|
|
*data_size = sizeof(AVFrame);
|
|
} else {
|
|
*data_size = 0;
|
|
buf_size = 0;
|
|
}
|
|
|
|
*(AVFrame *) data = cc->frame;
|
|
return buf_size;
|
|
}
|
|
|
|
static av_cold int cdg_decode_end(AVCodecContext *avctx)
|
|
{
|
|
CDGraphicsContext *cc = avctx->priv_data;
|
|
|
|
if (cc->frame.data[0])
|
|
avctx->release_buffer(avctx, &cc->frame);
|
|
|
|
return 0;
|
|
}
|
|
|
|
AVCodec ff_cdgraphics_decoder = {
|
|
.name = "cdgraphics",
|
|
.type = AVMEDIA_TYPE_VIDEO,
|
|
.id = AV_CODEC_ID_CDGRAPHICS,
|
|
.priv_data_size = sizeof(CDGraphicsContext),
|
|
.init = cdg_decode_init,
|
|
.close = cdg_decode_end,
|
|
.decode = cdg_decode_frame,
|
|
.capabilities = CODEC_CAP_DR1,
|
|
.long_name = NULL_IF_CONFIG_SMALL("CD Graphics video"),
|
|
};
|