yading@10: /*
yading@10:  * ASCII/ANSI art decoder
yading@10:  * Copyright (c) 2010 Peter Ross <pross@xvid.org>
yading@10:  *
yading@10:  * This file is part of FFmpeg.
yading@10:  *
yading@10:  * FFmpeg is free software; you can redistribute it and/or
yading@10:  * modify it under the terms of the GNU Lesser General Public
yading@10:  * License as published by the Free Software Foundation; either
yading@10:  * version 2.1 of the License, or (at your option) any later version.
yading@10:  *
yading@10:  * FFmpeg is distributed in the hope that it will be useful,
yading@10:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@10:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@10:  * Lesser General Public License for more details.
yading@10:  *
yading@10:  * You should have received a copy of the GNU Lesser General Public
yading@10:  * License along with FFmpeg; if not, write to the Free Software
yading@10:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@10:  */
yading@10: 
yading@10: /**
yading@10:  * @file
yading@10:  * ASCII/ANSI art decoder
yading@10:  */
yading@10: 
yading@10: #include "libavutil/common.h"
yading@10: #include "libavutil/frame.h"
yading@10: #include "libavutil/lfg.h"
yading@10: #include "libavutil/xga_font_data.h"
yading@10: #include "avcodec.h"
yading@10: #include "cga_data.h"
yading@10: #include "internal.h"
yading@10: 
yading@10: #define ATTR_BOLD         0x01  /**< Bold/Bright-foreground (mode 1) */
yading@10: #define ATTR_FAINT        0x02  /**< Faint (mode 2) */
yading@10: #define ATTR_UNDERLINE    0x08  /**< Underline (mode 4) */
yading@10: #define ATTR_BLINK        0x10  /**< Blink/Bright-background (mode 5) */
yading@10: #define ATTR_REVERSE      0x40  /**< Reverse (mode 7) */
yading@10: #define ATTR_CONCEALED    0x80  /**< Concealed (mode 8) */
yading@10: 
yading@10: #define DEFAULT_FG_COLOR     7  /**< CGA color index */
yading@10: #define DEFAULT_BG_COLOR     0
yading@10: #define DEFAULT_SCREEN_MODE  3  /**< 80x25 */
yading@10: 
yading@10: #define FONT_WIDTH           8  /**< Font width */
yading@10: 
yading@10: /** map ansi color index to cga palette index */
yading@10: static const uint8_t ansi_to_cga[16] = {
yading@10:     0,  4,  2,  6,  1,  5,  3, 7, 8, 12, 10, 14,  9, 13, 11, 15
yading@10: };
yading@10: 
yading@10: typedef struct {
yading@10:     AVFrame *frame;
yading@10:     int x;                /**< x cursor position (pixels) */
yading@10:     int y;                /**< y cursor position (pixels) */
yading@10:     int sx;               /**< saved x cursor position (pixels) */
yading@10:     int sy;               /**< saved y cursor position (pixels) */
yading@10:     const uint8_t* font;  /**< font */
yading@10:     int font_height;      /**< font height */
yading@10:     int attributes;       /**< attribute flags */
yading@10:     int fg;               /**< foreground color */
yading@10:     int bg;               /**< background color */
yading@10:     int first_frame;
yading@10: 
yading@10:     /* ansi parser state machine */
yading@10:     enum {
yading@10:         STATE_NORMAL = 0,
yading@10:         STATE_ESCAPE,
yading@10:         STATE_CODE,
yading@10:         STATE_MUSIC_PREAMBLE
yading@10:     } state;
yading@10: #define MAX_NB_ARGS 4
yading@10:     int args[MAX_NB_ARGS];
yading@10:     int nb_args;          /**< number of arguments (may exceed MAX_NB_ARGS) */
yading@10: } AnsiContext;
yading@10: 
yading@10: static av_cold int decode_init(AVCodecContext *avctx)
yading@10: {
yading@10:     AnsiContext *s = avctx->priv_data;
yading@10:     avctx->pix_fmt = AV_PIX_FMT_PAL8;
yading@10: 
yading@10:     s->frame = av_frame_alloc();
yading@10:     if (!s->frame)
yading@10:         return AVERROR(ENOMEM);
yading@10: 
yading@10:     /* defaults */
yading@10:     s->font        = avpriv_vga16_font;
yading@10:     s->font_height = 16;
yading@10:     s->fg          = DEFAULT_FG_COLOR;
yading@10:     s->bg          = DEFAULT_BG_COLOR;
yading@10: 
yading@10:     if (!avctx->width || !avctx->height)
yading@10:         avcodec_set_dimensions(avctx, 80<<3, 25<<4);
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static void set_palette(uint32_t *pal)
yading@10: {
yading@10:     int r, g, b;
yading@10:     memcpy(pal, ff_cga_palette, 16 * 4);
yading@10:     pal += 16;
yading@10: #define COLOR(x) ((x) * 40 + 55)
yading@10:     for (r = 0; r < 6; r++)
yading@10:         for (g = 0; g < 6; g++)
yading@10:             for (b = 0; b < 6; b++)
yading@10:                 *pal++ = 0xFF000000 | (COLOR(r) << 16) | (COLOR(g) << 8) | COLOR(b);
yading@10: #define GRAY(x) ((x) * 10 + 8)
yading@10:     for (g = 0; g < 24; g++)
yading@10:         *pal++ = 0xFF000000 | (GRAY(g) << 16) | (GRAY(g) << 8) | GRAY(g);
yading@10: }
yading@10: 
yading@10: static void hscroll(AVCodecContext *avctx)
yading@10: {
yading@10:     AnsiContext *s = avctx->priv_data;
yading@10:     int i;
yading@10: 
yading@10:     if (s->y < avctx->height - s->font_height) {
yading@10:         s->y += s->font_height;
yading@10:         return;
yading@10:     }
yading@10: 
yading@10:     i = 0;
yading@10:     for (; i < avctx->height - s->font_height; i++)
yading@10:         memcpy(s->frame->data[0] + i * s->frame->linesize[0],
yading@10:                s->frame->data[0] + (i + s->font_height) * s->frame->linesize[0],
yading@10:                avctx->width);
yading@10:     for (; i < avctx->height; i++)
yading@10:         memset(s->frame->data[0] + i * s->frame->linesize[0],
yading@10:             DEFAULT_BG_COLOR, avctx->width);
yading@10: }
yading@10: 
yading@10: static void erase_line(AVCodecContext * avctx, int xoffset, int xlength)
yading@10: {
yading@10:     AnsiContext *s = avctx->priv_data;
yading@10:     int i;
yading@10:     for (i = 0; i < s->font_height; i++)
yading@10:         memset(s->frame->data[0] + (s->y + i)*s->frame->linesize[0] + xoffset,
yading@10:             DEFAULT_BG_COLOR, xlength);
yading@10: }
yading@10: 
yading@10: static void erase_screen(AVCodecContext *avctx)
yading@10: {
yading@10:     AnsiContext *s = avctx->priv_data;
yading@10:     int i;
yading@10:     for (i = 0; i < avctx->height; i++)
yading@10:         memset(s->frame->data[0] + i * s->frame->linesize[0], DEFAULT_BG_COLOR, avctx->width);
yading@10:     s->x = s->y = 0;
yading@10: }
yading@10: 
yading@10: /**
yading@10:  * Draw character to screen
yading@10:  */
yading@10: static void draw_char(AVCodecContext *avctx, int c)
yading@10: {
yading@10:     AnsiContext *s = avctx->priv_data;
yading@10:     int fg = s->fg;
yading@10:     int bg = s->bg;
yading@10: 
yading@10:     if ((s->attributes & ATTR_BOLD))
yading@10:         fg += 8;
yading@10:     if ((s->attributes & ATTR_BLINK))
yading@10:         bg += 8;
yading@10:     if ((s->attributes & ATTR_REVERSE))
yading@10:         FFSWAP(int, fg, bg);
yading@10:     if ((s->attributes & ATTR_CONCEALED))
yading@10:         fg = bg;
yading@10:     ff_draw_pc_font(s->frame->data[0] + s->y * s->frame->linesize[0] + s->x,
yading@10:                     s->frame->linesize[0], s->font, s->font_height, c, fg, bg);
yading@10:     s->x += FONT_WIDTH;
yading@10:     if (s->x >= avctx->width) {
yading@10:         s->x = 0;
yading@10:         hscroll(avctx);
yading@10:     }
yading@10: }
yading@10: 
yading@10: /**
yading@10:  * Execute ANSI escape code
yading@10:  * @return 0 on success, negative on error
yading@10:  */
yading@10: static int execute_code(AVCodecContext * avctx, int c)
yading@10: {
yading@10:     AnsiContext *s = avctx->priv_data;
yading@10:     int ret, i, width, height;
yading@10:     switch(c) {
yading@10:     case 'A': //Cursor Up
yading@10:         s->y = FFMAX(s->y - (s->nb_args > 0 ? s->args[0]*s->font_height : s->font_height), 0);
yading@10:         break;
yading@10:     case 'B': //Cursor Down
yading@10:         s->y = FFMIN(s->y + (s->nb_args > 0 ? s->args[0]*s->font_height : s->font_height), avctx->height - s->font_height);
yading@10:         break;
yading@10:     case 'C': //Cursor Right
yading@10:         s->x = FFMIN(s->x + (s->nb_args > 0 ? s->args[0]*FONT_WIDTH : FONT_WIDTH), avctx->width  - FONT_WIDTH);
yading@10:         break;
yading@10:     case 'D': //Cursor Left
yading@10:         s->x = FFMAX(s->x - (s->nb_args > 0 ? s->args[0]*FONT_WIDTH : FONT_WIDTH), 0);
yading@10:         break;
yading@10:     case 'H': //Cursor Position
yading@10:     case 'f': //Horizontal and Vertical Position
yading@10:         s->y = s->nb_args > 0 ? av_clip((s->args[0] - 1)*s->font_height, 0, avctx->height - s->font_height) : 0;
yading@10:         s->x = s->nb_args > 1 ? av_clip((s->args[1] - 1)*FONT_WIDTH,     0, avctx->width  - FONT_WIDTH) : 0;
yading@10:         break;
yading@10:     case 'h': //set creen mode
yading@10:     case 'l': //reset screen mode
yading@10:         if (s->nb_args < 2)
yading@10:             s->args[0] = DEFAULT_SCREEN_MODE;
yading@10:         width = avctx->width;
yading@10:         height = avctx->height;
yading@10:         switch(s->args[0]) {
yading@10:         case 0: case 1: case 4: case 5: case 13: case 19: //320x200 (25 rows)
yading@10:             s->font = avpriv_cga_font;
yading@10:             s->font_height = 8;
yading@10:             width  = 40<<3;
yading@10:             height = 25<<3;
yading@10:             break;
yading@10:         case 2: case 3: //640x400 (25 rows)
yading@10:             s->font = avpriv_vga16_font;
yading@10:             s->font_height = 16;
yading@10:             width  = 80<<3;
yading@10:             height = 25<<4;
yading@10:             break;
yading@10:         case 6: case 14: //640x200 (25 rows)
yading@10:             s->font = avpriv_cga_font;
yading@10:             s->font_height = 8;
yading@10:             width  = 80<<3;
yading@10:             height = 25<<3;
yading@10:             break;
yading@10:         case 7: //set line wrapping
yading@10:             break;
yading@10:         case 15: case 16: //640x350 (43 rows)
yading@10:             s->font = avpriv_cga_font;
yading@10:             s->font_height = 8;
yading@10:             width  = 80<<3;
yading@10:             height = 43<<3;
yading@10:             break;
yading@10:         case 17: case 18: //640x480 (60 rows)
yading@10:             s->font = avpriv_cga_font;
yading@10:             s->font_height = 8;
yading@10:             width  = 80<<3;
yading@10:             height = 60<<4;
yading@10:             break;
yading@10:         default:
yading@10:             avpriv_request_sample(avctx, "Unsupported screen mode");
yading@10:         }
yading@10:         if (width != avctx->width || height != avctx->height) {
yading@10:             av_frame_unref(s->frame);
yading@10:             avcodec_set_dimensions(avctx, width, height);
yading@10:             if ((ret = ff_get_buffer(avctx, s->frame,
yading@10:                                      AV_GET_BUFFER_FLAG_REF)) < 0)
yading@10:                 return ret;
yading@10:             s->frame->pict_type           = AV_PICTURE_TYPE_I;
yading@10:             s->frame->palette_has_changed = 1;
yading@10:             set_palette((uint32_t *)s->frame->data[1]);
yading@10:             erase_screen(avctx);
yading@10:         } else if (c == 'l') {
yading@10:             erase_screen(avctx);
yading@10:         }
yading@10:         break;
yading@10:     case 'J': //Erase in Page
yading@10:         switch (s->args[0]) {
yading@10:         case 0:
yading@10:             erase_line(avctx, s->x, avctx->width - s->x);
yading@10:             if (s->y < avctx->height - s->font_height)
yading@10:                 memset(s->frame->data[0] + (s->y + s->font_height)*s->frame->linesize[0],
yading@10:                     DEFAULT_BG_COLOR, (avctx->height - s->y - s->font_height)*s->frame->linesize[0]);
yading@10:             break;
yading@10:         case 1:
yading@10:             erase_line(avctx, 0, s->x);
yading@10:             if (s->y > 0)
yading@10:                 memset(s->frame->data[0], DEFAULT_BG_COLOR, s->y * s->frame->linesize[0]);
yading@10:             break;
yading@10:         case 2:
yading@10:             erase_screen(avctx);
yading@10:         }
yading@10:         break;
yading@10:     case 'K': //Erase in Line
yading@10:         switch(s->args[0]) {
yading@10:         case 0:
yading@10:             erase_line(avctx, s->x, avctx->width - s->x);
yading@10:             break;
yading@10:         case 1:
yading@10:             erase_line(avctx, 0, s->x);
yading@10:             break;
yading@10:         case 2:
yading@10:             erase_line(avctx, 0, avctx->width);
yading@10:         }
yading@10:         break;
yading@10:     case 'm': //Select Graphics Rendition
yading@10:         if (s->nb_args == 0) {
yading@10:             s->nb_args = 1;
yading@10:             s->args[0] = 0;
yading@10:         }
yading@10:         for (i = 0; i < FFMIN(s->nb_args, MAX_NB_ARGS); i++) {
yading@10:             int m = s->args[i];
yading@10:             if (m == 0) {
yading@10:                 s->attributes = 0;
yading@10:                 s->fg = DEFAULT_FG_COLOR;
yading@10:                 s->bg = DEFAULT_BG_COLOR;
yading@10:             } else if (m == 1 || m == 2 || m == 4 || m == 5 || m == 7 || m == 8) {
yading@10:                 s->attributes |= 1 << (m - 1);
yading@10:             } else if (m >= 30 && m <= 37) {
yading@10:                 s->fg = ansi_to_cga[m - 30];
yading@10:             } else if (m == 38 && i + 2 < FFMIN(s->nb_args, MAX_NB_ARGS) && s->args[i + 1] == 5 && s->args[i + 2] < 256) {
yading@10:                 int index = s->args[i + 2];
yading@10:                 s->fg = index < 16 ? ansi_to_cga[index] : index;
yading@10:                 i += 2;
yading@10:             } else if (m == 39) {
yading@10:                 s->fg = ansi_to_cga[DEFAULT_FG_COLOR];
yading@10:             } else if (m >= 40 && m <= 47) {
yading@10:                 s->bg = ansi_to_cga[m - 40];
yading@10:             } else if (m == 48 && i + 2 < FFMIN(s->nb_args, MAX_NB_ARGS) && s->args[i + 1] == 5 && s->args[i + 2] < 256) {
yading@10:                 int index = s->args[i + 2];
yading@10:                 s->bg = index < 16 ? ansi_to_cga[index] : index;
yading@10:                 i += 2;
yading@10:             } else if (m == 49) {
yading@10:                 s->fg = ansi_to_cga[DEFAULT_BG_COLOR];
yading@10:             } else {
yading@10:                 avpriv_request_sample(avctx, "Unsupported rendition parameter");
yading@10:             }
yading@10:         }
yading@10:         break;
yading@10:     case 'n': //Device Status Report
yading@10:     case 'R': //report current line and column
yading@10:         /* ignore */
yading@10:         break;
yading@10:     case 's': //Save Cursor Position
yading@10:         s->sx = s->x;
yading@10:         s->sy = s->y;
yading@10:         break;
yading@10:     case 'u': //Restore Cursor Position
yading@10:         s->x = av_clip(s->sx, 0, avctx->width  - FONT_WIDTH);
yading@10:         s->y = av_clip(s->sy, 0, avctx->height - s->font_height);
yading@10:         break;
yading@10:     default:
yading@10:         avpriv_request_sample(avctx, "Unknown escape code");
yading@10:         break;
yading@10:     }
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static int decode_frame(AVCodecContext *avctx,
yading@10:                             void *data, int *got_frame,
yading@10:                             AVPacket *avpkt)
yading@10: {
yading@10:     AnsiContext *s = avctx->priv_data;
yading@10:     uint8_t *buf = avpkt->data;
yading@10:     int buf_size = avpkt->size;
yading@10:     const uint8_t *buf_end   = buf+buf_size;
yading@10:     int ret, i, count;
yading@10: 
yading@10:     if ((ret = ff_reget_buffer(avctx, s->frame)) < 0)
yading@10:         return ret;
yading@10:     if (!avctx->frame_number) {
yading@10:         for (i=0; i<avctx->height; i++)
yading@10:             memset(s->frame->data[0]+ i*s->frame->linesize[0], 0, avctx->width);
yading@10:         memset(s->frame->data[1], 0, AVPALETTE_SIZE);
yading@10:     }
yading@10: 
yading@10:     s->frame->pict_type           = AV_PICTURE_TYPE_I;
yading@10:     s->frame->palette_has_changed = 1;
yading@10:     set_palette((uint32_t *)s->frame->data[1]);
yading@10:     if (!s->first_frame) {
yading@10:         erase_screen(avctx);
yading@10:         s->first_frame = 1;
yading@10:     }
yading@10: 
yading@10:     while(buf < buf_end) {
yading@10:         switch(s->state) {
yading@10:         case STATE_NORMAL:
yading@10:             switch (buf[0]) {
yading@10:             case 0x00: //NUL
yading@10:             case 0x07: //BEL
yading@10:             case 0x1A: //SUB
yading@10:                 /* ignore */
yading@10:                 break;
yading@10:             case 0x08: //BS
yading@10:                 s->x = FFMAX(s->x - 1, 0);
yading@10:                 break;
yading@10:             case 0x09: //HT
yading@10:                 i = s->x / FONT_WIDTH;
yading@10:                 count = ((i + 8) & ~7) - i;
yading@10:                 for (i = 0; i < count; i++)
yading@10:                     draw_char(avctx, ' ');
yading@10:                 break;
yading@10:             case 0x0A: //LF
yading@10:                 hscroll(avctx);
yading@10:             case 0x0D: //CR
yading@10:                 s->x = 0;
yading@10:                 break;
yading@10:             case 0x0C: //FF
yading@10:                 erase_screen(avctx);
yading@10:                 break;
yading@10:             case 0x1B: //ESC
yading@10:                 s->state = STATE_ESCAPE;
yading@10:                 break;
yading@10:             default:
yading@10:                 draw_char(avctx, buf[0]);
yading@10:             }
yading@10:             break;
yading@10:         case STATE_ESCAPE:
yading@10:             if (buf[0] == '[') {
yading@10:                 s->state   = STATE_CODE;
yading@10:                 s->nb_args = 0;
yading@10:                 s->args[0] = -1;
yading@10:             } else {
yading@10:                 s->state = STATE_NORMAL;
yading@10:                 draw_char(avctx, 0x1B);
yading@10:                 continue;
yading@10:             }
yading@10:             break;
yading@10:         case STATE_CODE:
yading@10:             switch(buf[0]) {
yading@10:             case '0': case '1': case '2': case '3': case '4':
yading@10:             case '5': case '6': case '7': case '8': case '9':
yading@10:                 if (s->nb_args < MAX_NB_ARGS)
yading@10:                     s->args[s->nb_args] = FFMAX(s->args[s->nb_args], 0) * 10 + buf[0] - '0';
yading@10:                 break;
yading@10:             case ';':
yading@10:                 s->nb_args++;
yading@10:                 if (s->nb_args < MAX_NB_ARGS)
yading@10:                     s->args[s->nb_args] = 0;
yading@10:                 break;
yading@10:             case 'M':
yading@10:                 s->state = STATE_MUSIC_PREAMBLE;
yading@10:                 break;
yading@10:             case '=': case '?':
yading@10:                 /* ignore */
yading@10:                 break;
yading@10:             default:
yading@10:                 if (s->nb_args > MAX_NB_ARGS)
yading@10:                     av_log(avctx, AV_LOG_WARNING, "args overflow (%i)\n", s->nb_args);
yading@10:                 if (s->nb_args < MAX_NB_ARGS && s->args[s->nb_args] >= 0)
yading@10:                     s->nb_args++;
yading@10:                 if ((ret = execute_code(avctx, buf[0])) < 0)
yading@10:                     return ret;
yading@10:                 s->state = STATE_NORMAL;
yading@10:             }
yading@10:             break;
yading@10:         case STATE_MUSIC_PREAMBLE:
yading@10:             if (buf[0] == 0x0E || buf[0] == 0x1B)
yading@10:                 s->state = STATE_NORMAL;
yading@10:             /* ignore music data */
yading@10:             break;
yading@10:         }
yading@10:         buf++;
yading@10:     }
yading@10: 
yading@10:     *got_frame = 1;
yading@10:     if ((ret = av_frame_ref(data, s->frame)) < 0)
yading@10:         return ret;
yading@10:     return buf_size;
yading@10: }
yading@10: 
yading@10: static av_cold int decode_close(AVCodecContext *avctx)
yading@10: {
yading@10:     AnsiContext *s = avctx->priv_data;
yading@10: 
yading@10:     av_frame_free(&s->frame);
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: AVCodec ff_ansi_decoder = {
yading@10:     .name           = "ansi",
yading@10:     .type           = AVMEDIA_TYPE_VIDEO,
yading@10:     .id             = AV_CODEC_ID_ANSI,
yading@10:     .priv_data_size = sizeof(AnsiContext),
yading@10:     .init           = decode_init,
yading@10:     .close          = decode_close,
yading@10:     .decode         = decode_frame,
yading@10:     .capabilities   = CODEC_CAP_DR1,
yading@10:     .long_name      = NULL_IF_CONFIG_SMALL("ASCII/ANSI art"),
yading@10: };