496 lines
16 KiB
C
496 lines
16 KiB
C
/*
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* ASCII/ANSI art decoder
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* Copyright (c) 2010 Peter Ross <pross@xvid.org>
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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/**
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* @file
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* ASCII/ANSI art decoder
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*/
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#include "libavutil/common.h"
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#include "libavutil/frame.h"
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#include "libavutil/lfg.h"
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#include "libavutil/xga_font_data.h"
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#include "avcodec.h"
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#include "cga_data.h"
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#include "internal.h"
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#define ATTR_BOLD 0x01 /**< Bold/Bright-foreground (mode 1) */
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#define ATTR_FAINT 0x02 /**< Faint (mode 2) */
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#define ATTR_ITALICS 0x04 /**< Italics (mode 3) */
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#define ATTR_UNDERLINE 0x08 /**< Underline (mode 4) */
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#define ATTR_BLINK 0x10 /**< Blink/Bright-background (mode 5) */
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#define ATTR_REVERSE 0x40 /**< Reverse (mode 7) */
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#define ATTR_CONCEALED 0x80 /**< Concealed (mode 8) */
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#define DEFAULT_FG_COLOR 7 /**< CGA color index */
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#define DEFAULT_BG_COLOR 0
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#define DEFAULT_SCREEN_MODE 3 /**< 80x25 */
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#define FONT_WIDTH 8 /**< Font width */
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/** map ansi color index to cga palette index */
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static const uint8_t ansi_to_cga[16] = {
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0, 4, 2, 6, 1, 5, 3, 7, 8, 12, 10, 14, 9, 13, 11, 15
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};
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typedef struct AnsiContext {
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AVFrame *frame;
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int x; /**< x cursor position (pixels) */
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int y; /**< y cursor position (pixels) */
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int sx; /**< saved x cursor position (pixels) */
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int sy; /**< saved y cursor position (pixels) */
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const uint8_t* font; /**< font */
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int font_height; /**< font height */
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int attributes; /**< attribute flags */
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int fg; /**< foreground color */
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int bg; /**< background color */
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int first_frame;
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/* ansi parser state machine */
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enum {
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STATE_NORMAL = 0,
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STATE_ESCAPE,
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STATE_CODE,
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STATE_MUSIC_PREAMBLE
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} state;
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#define MAX_NB_ARGS 4
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int args[MAX_NB_ARGS];
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int nb_args; /**< number of arguments (may exceed MAX_NB_ARGS) */
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} AnsiContext;
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static av_cold int decode_init(AVCodecContext *avctx)
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{
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AnsiContext *s = avctx->priv_data;
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avctx->pix_fmt = AV_PIX_FMT_PAL8;
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/* defaults */
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s->font = avpriv_vga16_font;
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s->font_height = 16;
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s->fg = DEFAULT_FG_COLOR;
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s->bg = DEFAULT_BG_COLOR;
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if (!avctx->width || !avctx->height) {
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int ret = ff_set_dimensions(avctx, 80 << 3, 25 << 4);
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if (ret < 0)
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return ret;
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} else if (avctx->width % FONT_WIDTH || avctx->height % s->font_height) {
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av_log(avctx, AV_LOG_ERROR, "Invalid dimensions %d %d\n", avctx->width, avctx->height);
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return AVERROR(EINVAL);
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}
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s->frame = av_frame_alloc();
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if (!s->frame)
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return AVERROR(ENOMEM);
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return 0;
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}
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static void set_palette(uint32_t *pal)
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{
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int r, g, b;
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memcpy(pal, ff_cga_palette, 16 * 4);
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pal += 16;
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#define COLOR(x) ((x) * 40 + 55)
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for (r = 0; r < 6; r++)
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for (g = 0; g < 6; g++)
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for (b = 0; b < 6; b++)
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*pal++ = 0xFF000000 | (COLOR(r) << 16) | (COLOR(g) << 8) | COLOR(b);
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#define GRAY(x) ((x) * 10 + 8)
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for (g = 0; g < 24; g++)
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*pal++ = 0xFF000000 | (GRAY(g) << 16) | (GRAY(g) << 8) | GRAY(g);
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}
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static void hscroll(AVCodecContext *avctx)
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{
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AnsiContext *s = avctx->priv_data;
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int i;
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if (s->y <= avctx->height - 2*s->font_height) {
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s->y += s->font_height;
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return;
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}
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i = 0;
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for (; i < avctx->height - s->font_height; i++)
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memcpy(s->frame->data[0] + i * s->frame->linesize[0],
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s->frame->data[0] + (i + s->font_height) * s->frame->linesize[0],
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avctx->width);
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for (; i < avctx->height; i++)
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memset(s->frame->data[0] + i * s->frame->linesize[0],
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DEFAULT_BG_COLOR, avctx->width);
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}
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static void erase_line(AVCodecContext * avctx, int xoffset, int xlength)
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{
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AnsiContext *s = avctx->priv_data;
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int i;
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for (i = 0; i < s->font_height; i++)
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memset(s->frame->data[0] + (s->y + i)*s->frame->linesize[0] + xoffset,
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DEFAULT_BG_COLOR, xlength);
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}
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static void erase_screen(AVCodecContext *avctx)
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{
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AnsiContext *s = avctx->priv_data;
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int i;
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for (i = 0; i < avctx->height; i++)
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memset(s->frame->data[0] + i * s->frame->linesize[0], DEFAULT_BG_COLOR, avctx->width);
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s->x = s->y = 0;
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}
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/**
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* Draw character to screen
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*/
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static void draw_char(AVCodecContext *avctx, int c)
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{
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AnsiContext *s = avctx->priv_data;
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int fg = s->fg;
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int bg = s->bg;
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if ((s->attributes & ATTR_BOLD))
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fg += 8;
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if ((s->attributes & ATTR_BLINK))
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bg += 8;
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if ((s->attributes & ATTR_REVERSE))
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FFSWAP(int, fg, bg);
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if ((s->attributes & ATTR_CONCEALED))
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fg = bg;
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ff_draw_pc_font(s->frame->data[0] + s->y * s->frame->linesize[0] + s->x,
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s->frame->linesize[0], s->font, s->font_height, c, fg, bg);
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s->x += FONT_WIDTH;
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if (s->x > avctx->width - FONT_WIDTH) {
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s->x = 0;
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hscroll(avctx);
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}
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}
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/**
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* Execute ANSI escape code
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* @return 0 on success, negative on error
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*/
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static int execute_code(AVCodecContext * avctx, int c)
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{
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AnsiContext *s = avctx->priv_data;
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int ret, i;
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int width = avctx->width;
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int height = avctx->height;
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switch(c) {
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case 'A': //Cursor Up
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s->y = FFMAX(s->y - (s->nb_args > 0 ? s->args[0]*s->font_height : s->font_height), 0);
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break;
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case 'B': //Cursor Down
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s->y = FFMIN(s->y + (s->nb_args > 0 ? s->args[0]*s->font_height : s->font_height), avctx->height - s->font_height);
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break;
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case 'C': //Cursor Right
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s->x = FFMIN(s->x + (s->nb_args > 0 ? s->args[0]*FONT_WIDTH : FONT_WIDTH), avctx->width - FONT_WIDTH);
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break;
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case 'D': //Cursor Left
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s->x = FFMAX(s->x - (s->nb_args > 0 ? s->args[0]*FONT_WIDTH : FONT_WIDTH), 0);
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break;
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case 'H': //Cursor Position
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case 'f': //Horizontal and Vertical Position
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s->y = s->nb_args > 0 ? av_clip((s->args[0] - 1)*s->font_height, 0, avctx->height - s->font_height) : 0;
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s->x = s->nb_args > 1 ? av_clip((s->args[1] - 1)*FONT_WIDTH, 0, avctx->width - FONT_WIDTH) : 0;
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break;
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case 'h': //set screen mode
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case 'l': //reset screen mode
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if (s->nb_args < 2)
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s->args[0] = DEFAULT_SCREEN_MODE;
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switch(s->args[0]) {
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case 0: case 1: case 4: case 5: case 13: case 19: //320x200 (25 rows)
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s->font = avpriv_cga_font;
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s->font_height = 8;
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width = 40<<3;
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height = 25<<3;
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break;
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case 2: case 3: //640x400 (25 rows)
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s->font = avpriv_vga16_font;
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s->font_height = 16;
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width = 80<<3;
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height = 25<<4;
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break;
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case 6: case 14: //640x200 (25 rows)
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s->font = avpriv_cga_font;
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s->font_height = 8;
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width = 80<<3;
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height = 25<<3;
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break;
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case 7: //set line wrapping
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break;
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case 15: case 16: //640x350 (43 rows)
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s->font = avpriv_cga_font;
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s->font_height = 8;
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width = 80<<3;
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height = 43<<3;
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break;
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case 17: case 18: //640x480 (60 rows)
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s->font = avpriv_cga_font;
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s->font_height = 8;
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width = 80<<3;
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height = 60<<4;
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break;
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default:
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avpriv_request_sample(avctx, "Unsupported screen mode");
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}
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s->x = av_clip(s->x, 0, width - FONT_WIDTH);
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s->y = av_clip(s->y, 0, height - s->font_height);
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if (width != avctx->width || height != avctx->height) {
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av_frame_unref(s->frame);
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ret = ff_set_dimensions(avctx, width, height);
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if (ret < 0)
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return ret;
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if ((ret = ff_get_buffer(avctx, s->frame,
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AV_GET_BUFFER_FLAG_REF)) < 0)
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return ret;
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s->frame->pict_type = AV_PICTURE_TYPE_I;
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s->frame->palette_has_changed = 1;
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set_palette((uint32_t *)s->frame->data[1]);
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erase_screen(avctx);
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} else if (c == 'l') {
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erase_screen(avctx);
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}
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break;
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case 'J': //Erase in Page
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switch (s->args[0]) {
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case 0:
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erase_line(avctx, s->x, avctx->width - s->x);
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if (s->y < avctx->height - s->font_height)
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memset(s->frame->data[0] + (s->y + s->font_height)*s->frame->linesize[0],
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DEFAULT_BG_COLOR, (avctx->height - s->y - s->font_height)*s->frame->linesize[0]);
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break;
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case 1:
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erase_line(avctx, 0, s->x);
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if (s->y > 0)
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memset(s->frame->data[0], DEFAULT_BG_COLOR, s->y * s->frame->linesize[0]);
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break;
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case 2:
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erase_screen(avctx);
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}
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break;
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case 'K': //Erase in Line
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switch(s->args[0]) {
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case 0:
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erase_line(avctx, s->x, avctx->width - s->x);
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break;
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case 1:
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erase_line(avctx, 0, s->x);
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break;
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case 2:
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erase_line(avctx, 0, avctx->width);
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}
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break;
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case 'm': //Select Graphics Rendition
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if (s->nb_args == 0) {
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s->nb_args = 1;
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s->args[0] = 0;
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}
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for (i = 0; i < FFMIN(s->nb_args, MAX_NB_ARGS); i++) {
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int m = s->args[i];
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if (m == 0) {
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s->attributes = 0;
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s->fg = DEFAULT_FG_COLOR;
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s->bg = DEFAULT_BG_COLOR;
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} else if (m == 1 || m == 2 || m == 3 || m == 4 || m == 5 || m == 7 || m == 8) {
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s->attributes |= 1 << (m - 1);
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} else if (m >= 30 && m <= 37) {
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s->fg = ansi_to_cga[m - 30];
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} else if (m == 38 && i + 2 < FFMIN(s->nb_args, MAX_NB_ARGS) && s->args[i + 1] == 5 && s->args[i + 2] < 256) {
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int index = s->args[i + 2];
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s->fg = index < 16 ? ansi_to_cga[index] : index;
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i += 2;
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} else if (m == 39) {
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s->fg = ansi_to_cga[DEFAULT_FG_COLOR];
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} else if (m >= 40 && m <= 47) {
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s->bg = ansi_to_cga[m - 40];
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} else if (m == 48 && i + 2 < FFMIN(s->nb_args, MAX_NB_ARGS) && s->args[i + 1] == 5 && s->args[i + 2] < 256) {
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int index = s->args[i + 2];
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s->bg = index < 16 ? ansi_to_cga[index] : index;
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i += 2;
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} else if (m == 49) {
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s->fg = ansi_to_cga[DEFAULT_BG_COLOR];
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} else {
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avpriv_request_sample(avctx, "Unsupported rendition parameter");
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}
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}
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break;
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case 'n': //Device Status Report
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case 'R': //report current line and column
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/* ignore */
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break;
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case 's': //Save Cursor Position
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s->sx = s->x;
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s->sy = s->y;
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break;
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case 'u': //Restore Cursor Position
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s->x = av_clip(s->sx, 0, avctx->width - FONT_WIDTH);
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s->y = av_clip(s->sy, 0, avctx->height - s->font_height);
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break;
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default:
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avpriv_request_sample(avctx, "Unknown escape code");
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break;
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}
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s->x = av_clip(s->x, 0, avctx->width - FONT_WIDTH);
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s->y = av_clip(s->y, 0, avctx->height - s->font_height);
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return 0;
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}
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static int decode_frame(AVCodecContext *avctx,
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void *data, int *got_frame,
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AVPacket *avpkt)
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{
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AnsiContext *s = avctx->priv_data;
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uint8_t *buf = avpkt->data;
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int buf_size = avpkt->size;
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const uint8_t *buf_end = buf+buf_size;
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int ret, i, count;
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if ((ret = ff_reget_buffer(avctx, s->frame, 0)) < 0)
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return ret;
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if (!avctx->frame_number) {
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for (i=0; i<avctx->height; i++)
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memset(s->frame->data[0]+ i*s->frame->linesize[0], 0, avctx->width);
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memset(s->frame->data[1], 0, AVPALETTE_SIZE);
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}
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s->frame->pict_type = AV_PICTURE_TYPE_I;
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s->frame->palette_has_changed = 1;
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set_palette((uint32_t *)s->frame->data[1]);
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if (!s->first_frame) {
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erase_screen(avctx);
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s->first_frame = 1;
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}
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while(buf < buf_end) {
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switch(s->state) {
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case STATE_NORMAL:
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switch (buf[0]) {
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case 0x00: //NUL
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case 0x07: //BEL
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case 0x1A: //SUB
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/* ignore */
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break;
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case 0x08: //BS
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s->x = FFMAX(s->x - 1, 0);
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break;
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case 0x09: //HT
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i = s->x / FONT_WIDTH;
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count = ((i + 8) & ~7) - i;
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for (i = 0; i < count; i++)
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draw_char(avctx, ' ');
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break;
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case 0x0A: //LF
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hscroll(avctx);
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case 0x0D: //CR
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s->x = 0;
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break;
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case 0x0C: //FF
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erase_screen(avctx);
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break;
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case 0x1B: //ESC
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s->state = STATE_ESCAPE;
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break;
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default:
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draw_char(avctx, buf[0]);
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}
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break;
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case STATE_ESCAPE:
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if (buf[0] == '[') {
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s->state = STATE_CODE;
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s->nb_args = 0;
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s->args[0] = -1;
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} else {
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s->state = STATE_NORMAL;
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draw_char(avctx, 0x1B);
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continue;
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}
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break;
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case STATE_CODE:
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switch(buf[0]) {
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case '0': case '1': case '2': case '3': case '4':
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case '5': case '6': case '7': case '8': case '9':
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if (s->nb_args < MAX_NB_ARGS && s->args[s->nb_args] < 6553)
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s->args[s->nb_args] = FFMAX(s->args[s->nb_args], 0) * 10 + buf[0] - '0';
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break;
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case ';':
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if (s->nb_args < MAX_NB_ARGS)
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s->nb_args++;
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if (s->nb_args < MAX_NB_ARGS)
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s->args[s->nb_args] = 0;
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break;
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case 'M':
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s->state = STATE_MUSIC_PREAMBLE;
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break;
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case '=': case '?':
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/* ignore */
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break;
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default:
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if (s->nb_args > MAX_NB_ARGS)
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av_log(avctx, AV_LOG_WARNING, "args overflow (%i)\n", s->nb_args);
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if (s->nb_args < MAX_NB_ARGS && s->args[s->nb_args] >= 0)
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s->nb_args++;
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if ((ret = execute_code(avctx, buf[0])) < 0)
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return ret;
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s->state = STATE_NORMAL;
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}
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break;
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case STATE_MUSIC_PREAMBLE:
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if (buf[0] == 0x0E || buf[0] == 0x1B)
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s->state = STATE_NORMAL;
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/* ignore music data */
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break;
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}
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buf++;
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}
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|
|
|
*got_frame = 1;
|
|
if ((ret = av_frame_ref(data, s->frame)) < 0)
|
|
return ret;
|
|
return buf_size;
|
|
}
|
|
|
|
static av_cold int decode_close(AVCodecContext *avctx)
|
|
{
|
|
AnsiContext *s = avctx->priv_data;
|
|
|
|
av_frame_free(&s->frame);
|
|
return 0;
|
|
}
|
|
|
|
static const AVCodecDefault ansi_defaults[] = {
|
|
{ "max_pixels", "640*480" },
|
|
{ NULL },
|
|
};
|
|
|
|
AVCodec ff_ansi_decoder = {
|
|
.name = "ansi",
|
|
.long_name = NULL_IF_CONFIG_SMALL("ASCII/ANSI art"),
|
|
.type = AVMEDIA_TYPE_VIDEO,
|
|
.id = AV_CODEC_ID_ANSI,
|
|
.priv_data_size = sizeof(AnsiContext),
|
|
.init = decode_init,
|
|
.close = decode_close,
|
|
.decode = decode_frame,
|
|
.capabilities = AV_CODEC_CAP_DR1,
|
|
.caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
|
|
.defaults = ansi_defaults,
|
|
};
|