libavcodec/bintext.c
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00001 /*
00002  * Binary text decoder
00003  * eXtended BINary text (XBIN) decoder
00004  * iCEDraw File decoder
00005  * Copyright (c) 2010 Peter Ross (pross@xvid.org)
00006  *
00007  * This file is part of FFmpeg.
00008  *
00009  * FFmpeg is free software; you can redistribute it and/or
00010  * modify it under the terms of the GNU Lesser General Public
00011  * License as published by the Free Software Foundation; either
00012  * version 2.1 of the License, or (at your option) any later version.
00013  *
00014  * FFmpeg is distributed in the hope that it will be useful,
00015  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00016  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00017  * Lesser General Public License for more details.
00018  *
00019  * You should have received a copy of the GNU Lesser General Public
00020  * License along with FFmpeg; if not, write to the Free Software
00021  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00022  */
00023 
00031 #include "libavutil/intreadwrite.h"
00032 #include "avcodec.h"
00033 #include "cga_data.h"
00034 #include "bintext.h"
00035 
00036 typedef struct XbinContext {
00037     AVFrame frame;
00038     int palette[16];
00039     int flags;
00040     int font_height;
00041     const uint8_t *font;
00042     int x, y;
00043 } XbinContext;
00044 
00045 static av_cold int decode_init(AVCodecContext *avctx)
00046 {
00047     XbinContext *s = avctx->priv_data;
00048     uint8_t *p;
00049     int i;
00050 
00051     avctx->pix_fmt = PIX_FMT_PAL8;
00052     p = avctx->extradata;
00053     if (p) {
00054         s->font_height = p[0];
00055         s->flags = p[1];
00056         p += 2;
00057     } else {
00058         s->font_height = 8;
00059         s->flags = 0;
00060     }
00061 
00062     if ((s->flags & BINTEXT_PALETTE)) {
00063         for (i = 0; i < 16; i++) {
00064             s->palette[i] = 0xFF000000 | (AV_RB24(p) << 2) | ((AV_RB24(p) >> 4) & 0x30303);
00065             p += 3;
00066         }
00067     } else {
00068         for (i = 0; i < 16; i++)
00069             s->palette[i] = 0xFF000000 | ff_cga_palette[i];
00070     }
00071 
00072     if ((s->flags & BINTEXT_FONT)) {
00073         s->font = p;
00074     } else {
00075         switch(s->font_height) {
00076         default:
00077             av_log(avctx, AV_LOG_WARNING, "font height %i not supported\n", s->font_height);
00078             s->font_height = 8;
00079         case 8:
00080             s->font = ff_cga_font;
00081             break;
00082         case 16:
00083             s->font = ff_vga16_font;
00084             break;
00085         }
00086     }
00087 
00088     return 0;
00089 }
00090 
00091 #define DEFAULT_BG_COLOR 0
00092 static void hscroll(AVCodecContext *avctx)
00093 {
00094     XbinContext *s = avctx->priv_data;
00095     if (s->y < avctx->height - s->font_height) {
00096         s->y += s->font_height;
00097     } else {
00098         memmove(s->frame.data[0], s->frame.data[0] + s->font_height*s->frame.linesize[0],
00099             (avctx->height - s->font_height)*s->frame.linesize[0]);
00100         memset(s->frame.data[0] + (avctx->height - s->font_height)*s->frame.linesize[0],
00101             DEFAULT_BG_COLOR, s->font_height * s->frame.linesize[0]);
00102     }
00103 }
00104 
00105 #define FONT_WIDTH 8
00106 
00110 static void draw_char(AVCodecContext *avctx, int c, int a)
00111 {
00112     XbinContext *s = avctx->priv_data;
00113     if (s->y > avctx->height - s->font_height)
00114         return;
00115     ff_draw_pc_font(s->frame.data[0] + s->y * s->frame.linesize[0] + s->x,
00116                     s->frame.linesize[0], s->font, s->font_height, c,
00117                     a & 0x0F, a >> 4);
00118     s->x += FONT_WIDTH;
00119     if (s->x > avctx->width - FONT_WIDTH) {
00120         s->x = 0;
00121         s->y += s->font_height;
00122     }
00123 }
00124 
00125 static int decode_frame(AVCodecContext *avctx,
00126                             void *data, int *data_size,
00127                             AVPacket *avpkt)
00128 {
00129     XbinContext *s = avctx->priv_data;
00130     const uint8_t *buf = avpkt->data;
00131     int buf_size = avpkt->size;
00132     const uint8_t *buf_end = buf+buf_size;
00133 
00134     s->x = s->y = 0;
00135     s->frame.buffer_hints = FF_BUFFER_HINTS_VALID |
00136                             FF_BUFFER_HINTS_PRESERVE |
00137                             FF_BUFFER_HINTS_REUSABLE;
00138     if (avctx->reget_buffer(avctx, &s->frame)) {
00139         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
00140         return -1;
00141     }
00142     s->frame.pict_type           = AV_PICTURE_TYPE_I;
00143     s->frame.palette_has_changed = 1;
00144     memcpy(s->frame.data[1], s->palette, 16 * 4);
00145 
00146     if (avctx->codec_id == CODEC_ID_XBIN) {
00147         while (buf + 2 < buf_end) {
00148             int i,c,a;
00149             int type  = *buf >> 6;
00150             int count = (*buf & 0x3F) + 1;
00151             buf++;
00152             switch (type) {
00153             case 0: //no compression
00154                 for (i = 0; i < count && buf + 1 < buf_end; i++) {
00155                     draw_char(avctx, buf[0], buf[1]);
00156                     buf += 2;
00157                 }
00158                 break;
00159             case 1: //character compression
00160                 c = *buf++;
00161                 for (i = 0; i < count && buf < buf_end; i++)
00162                     draw_char(avctx, c, *buf++);
00163                 break;
00164             case 2: //attribute compression
00165                 a = *buf++;
00166                 for (i = 0; i < count && buf < buf_end; i++)
00167                     draw_char(avctx, *buf++, a);
00168                 break;
00169             case 3: //character/attribute compression
00170                 c = *buf++;
00171                 a = *buf++;
00172                 for (i = 0; i < count && buf < buf_end; i++)
00173                     draw_char(avctx, c, a);
00174                 break;
00175             }
00176         }
00177     } else if (avctx->codec_id == CODEC_ID_IDF) {
00178         while (buf + 2 < buf_end) {
00179             if (AV_RL16(buf) == 1) {
00180                int i;
00181                if (buf + 6 > buf_end)
00182                    break;
00183                for (i = 0; i < buf[2]; i++)
00184                    draw_char(avctx, buf[4], buf[5]);
00185                buf += 6;
00186             } else {
00187                draw_char(avctx, buf[0], buf[1]);
00188                buf += 2;
00189             }
00190         }
00191     } else {
00192         while (buf + 1 < buf_end) {
00193             draw_char(avctx, buf[0], buf[1]);
00194             buf += 2;
00195         }
00196     }
00197 
00198     *data_size = sizeof(AVFrame);
00199     *(AVFrame*)data = s->frame;
00200     return buf_size;
00201 }
00202 
00203 static av_cold int decode_end(AVCodecContext *avctx)
00204 {
00205     XbinContext *s = avctx->priv_data;
00206 
00207     if (s->frame.data[0])
00208         avctx->release_buffer(avctx, &s->frame);
00209 
00210     return 0;
00211 }
00212 
00213 AVCodec ff_bintext_decoder = {
00214     .name           = "bintext",
00215     .type           = AVMEDIA_TYPE_VIDEO,
00216     .id             = CODEC_ID_BINTEXT,
00217     .priv_data_size = sizeof(XbinContext),
00218     .init           = decode_init,
00219     .close          = decode_end,
00220     .decode         = decode_frame,
00221     .capabilities   = CODEC_CAP_DR1,
00222     .long_name = NULL_IF_CONFIG_SMALL("Binary text"),
00223 };
00224 
00225 AVCodec ff_xbin_decoder = {
00226     .name           = "xbin",
00227     .type           = AVMEDIA_TYPE_VIDEO,
00228     .id             = CODEC_ID_XBIN,
00229     .priv_data_size = sizeof(XbinContext),
00230     .init           = decode_init,
00231     .close          = decode_end,
00232     .decode         = decode_frame,
00233     .capabilities   = CODEC_CAP_DR1,
00234     .long_name = NULL_IF_CONFIG_SMALL("eXtended BINary text"),
00235 };
00236 
00237 AVCodec ff_idf_decoder = {
00238     .name           = "idf",
00239     .type           = AVMEDIA_TYPE_VIDEO,
00240     .id             = CODEC_ID_IDF,
00241     .priv_data_size = sizeof(XbinContext),
00242     .init           = decode_init,
00243     .close          = decode_end,
00244     .decode         = decode_frame,
00245     .capabilities   = CODEC_CAP_DR1,
00246     .long_name = NULL_IF_CONFIG_SMALL("iCEDraw text"),
00247 };