yading@10: /*
yading@10:  * Copyright (c) 2012 Clément Bœsch
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:  * MicroDVD subtitle decoder
yading@10:  *
yading@10:  * Based on the specifications found here:
yading@10:  * https://trac.videolan.org/vlc/ticket/1825#comment:6
yading@10:  */
yading@10: 
yading@10: #include "libavutil/avstring.h"
yading@10: #include "libavutil/parseutils.h"
yading@10: #include "libavutil/bprint.h"
yading@10: #include "avcodec.h"
yading@10: #include "ass.h"
yading@10: 
yading@10: static int indexof(const char *s, int c)
yading@10: {
yading@10:     char *f = strchr(s, c);
yading@10:     return f ? (f - s) : -1;
yading@10: }
yading@10: 
yading@10: struct microdvd_tag {
yading@10:     char key;
yading@10:     int persistent;
yading@10:     uint32_t data1;
yading@10:     uint32_t data2;
yading@10:     char *data_string;
yading@10:     int data_string_len;
yading@10: };
yading@10: 
yading@10: #define MICRODVD_PERSISTENT_OFF     0
yading@10: #define MICRODVD_PERSISTENT_ON      1
yading@10: #define MICRODVD_PERSISTENT_OPENED  2
yading@10: 
yading@10: // Color, Font, Size, cHarset, stYle, Position, cOordinate
yading@10: #define MICRODVD_TAGS "cfshyYpo"
yading@10: 
yading@10: static void microdvd_set_tag(struct microdvd_tag *tags, struct microdvd_tag tag)
yading@10: {
yading@10:     int tag_index = indexof(MICRODVD_TAGS, tag.key);
yading@10: 
yading@10:     if (tag_index < 0)
yading@10:         return;
yading@10:     memcpy(&tags[tag_index], &tag, sizeof(tag));
yading@10: }
yading@10: 
yading@10: // italic, bold, underline, strike-through
yading@10: #define MICRODVD_STYLES "ibus"
yading@10: 
yading@10: static char *microdvd_load_tags(struct microdvd_tag *tags, char *s)
yading@10: {
yading@10:     while (*s == '{') {
yading@10:         char *start = s;
yading@10:         char tag_char = *(s + 1);
yading@10:         struct microdvd_tag tag = {0};
yading@10: 
yading@10:         if (!tag_char || *(s + 2) != ':')
yading@10:             break;
yading@10:         s += 3;
yading@10: 
yading@10:         switch (tag_char) {
yading@10: 
yading@10:         /* Style */
yading@10:         case 'Y':
yading@10:             tag.persistent = MICRODVD_PERSISTENT_ON;
yading@10:         case 'y':
yading@10:             while (*s && *s != '}') {
yading@10:                 int style_index = indexof(MICRODVD_STYLES, *s);
yading@10: 
yading@10:                 if (style_index >= 0)
yading@10:                     tag.data1 |= (1 << style_index);
yading@10:                 s++;
yading@10:             }
yading@10:             if (*s != '}')
yading@10:                 break;
yading@10:             /* We must distinguish persistent and non-persistent styles
yading@10:              * to handle this kind of style tags: {y:ib}{Y:us} */
yading@10:             tag.key = tag_char;
yading@10:             break;
yading@10: 
yading@10:         /* Color */
yading@10:         case 'C':
yading@10:             tag.persistent = MICRODVD_PERSISTENT_ON;
yading@10:         case 'c':
yading@10:             if (*s == '$')
yading@10:                 s++;
yading@10:             tag.data1 = strtol(s, &s, 16) & 0x00ffffff;
yading@10:             if (*s != '}')
yading@10:                 break;
yading@10:             tag.key = 'c';
yading@10:             break;
yading@10: 
yading@10:         /* Font name */
yading@10:         case 'F':
yading@10:             tag.persistent = MICRODVD_PERSISTENT_ON;
yading@10:         case 'f': {
yading@10:             int len = indexof(s, '}');
yading@10:             if (len < 0)
yading@10:                 break;
yading@10:             tag.data_string = s;
yading@10:             tag.data_string_len = len;
yading@10:             s += len;
yading@10:             tag.key = 'f';
yading@10:             break;
yading@10:         }
yading@10: 
yading@10:         /* Font size */
yading@10:         case 'S':
yading@10:             tag.persistent = MICRODVD_PERSISTENT_ON;
yading@10:         case 's':
yading@10:             tag.data1 = strtol(s, &s, 10);
yading@10:             if (*s != '}')
yading@10:                 break;
yading@10:             tag.key = 's';
yading@10:             break;
yading@10: 
yading@10:         /* Charset */
yading@10:         case 'H': {
yading@10:             //TODO: not yet handled, just parsed.
yading@10:             int len = indexof(s, '}');
yading@10:             if (len < 0)
yading@10:                 break;
yading@10:             tag.data_string = s;
yading@10:             tag.data_string_len = len;
yading@10:             s += len;
yading@10:             tag.key = 'h';
yading@10:             break;
yading@10:         }
yading@10: 
yading@10:         /* Position */
yading@10:         case 'P':
yading@10:             tag.persistent = MICRODVD_PERSISTENT_ON;
yading@10:             tag.data1 = (*s++ == '1');
yading@10:             if (*s != '}')
yading@10:                 break;
yading@10:             tag.key = 'p';
yading@10:             break;
yading@10: 
yading@10:         /* Coordinates */
yading@10:         case 'o':
yading@10:             tag.persistent = MICRODVD_PERSISTENT_ON;
yading@10:             tag.data1 = strtol(s, &s, 10);
yading@10:             if (*s != ',')
yading@10:                 break;
yading@10:             s++;
yading@10:             tag.data2 = strtol(s, &s, 10);
yading@10:             if (*s != '}')
yading@10:                 break;
yading@10:             tag.key = 'o';
yading@10:             break;
yading@10: 
yading@10:         default:    /* Unknown tag, we consider it's text */
yading@10:             break;
yading@10:         }
yading@10: 
yading@10:         if (tag.key == 0)
yading@10:             return start;
yading@10: 
yading@10:         microdvd_set_tag(tags, tag);
yading@10:         s++;
yading@10:     }
yading@10:     return s;
yading@10: }
yading@10: 
yading@10: static void microdvd_open_tags(AVBPrint *new_line, struct microdvd_tag *tags)
yading@10: {
yading@10:     int i, sidx;
yading@10:     for (i = 0; i < sizeof(MICRODVD_TAGS) - 1; i++) {
yading@10:         if (tags[i].persistent == MICRODVD_PERSISTENT_OPENED)
yading@10:             continue;
yading@10:         switch (tags[i].key) {
yading@10:         case 'Y':
yading@10:         case 'y':
yading@10:             for (sidx = 0; sidx < sizeof(MICRODVD_STYLES) - 1; sidx++)
yading@10:                 if (tags[i].data1 & (1 << sidx))
yading@10:                     av_bprintf(new_line, "{\\%c1}", MICRODVD_STYLES[sidx]);
yading@10:             break;
yading@10: 
yading@10:         case 'c':
yading@10:             av_bprintf(new_line, "{\\c&H%06X&}", tags[i].data1);
yading@10:             break;
yading@10: 
yading@10:         case 'f':
yading@10:             av_bprintf(new_line, "{\\fn%.*s}",
yading@10:                        tags[i].data_string_len, tags[i].data_string);
yading@10:             break;
yading@10: 
yading@10:         case 's':
yading@10:             av_bprintf(new_line, "{\\fs%d}", tags[i].data1);
yading@10:             break;
yading@10: 
yading@10:         case 'p':
yading@10:             if (tags[i].data1 == 0)
yading@10:                 av_bprintf(new_line, "{\\an8}");
yading@10:             break;
yading@10: 
yading@10:         case 'o':
yading@10:             av_bprintf(new_line, "{\\pos(%d,%d)}",
yading@10:                        tags[i].data1, tags[i].data2);
yading@10:             break;
yading@10:         }
yading@10:         if (tags[i].persistent == MICRODVD_PERSISTENT_ON)
yading@10:             tags[i].persistent = MICRODVD_PERSISTENT_OPENED;
yading@10:     }
yading@10: }
yading@10: 
yading@10: static void microdvd_close_no_persistent_tags(AVBPrint *new_line,
yading@10:                                               struct microdvd_tag *tags)
yading@10: {
yading@10:     int i, sidx;
yading@10: 
yading@10:     for (i = sizeof(MICRODVD_TAGS) - 2; i >= 0; i--) {
yading@10:         if (tags[i].persistent != MICRODVD_PERSISTENT_OFF)
yading@10:             continue;
yading@10:         switch (tags[i].key) {
yading@10: 
yading@10:         case 'y':
yading@10:             for (sidx = sizeof(MICRODVD_STYLES) - 2; sidx >= 0; sidx--)
yading@10:                 if (tags[i].data1 & (1 << sidx))
yading@10:                     av_bprintf(new_line, "{\\%c0}", MICRODVD_STYLES[sidx]);
yading@10:             break;
yading@10: 
yading@10:         case 'c':
yading@10:             av_bprintf(new_line, "{\\c}");
yading@10:             break;
yading@10: 
yading@10:         case 'f':
yading@10:             av_bprintf(new_line, "{\\fn}");
yading@10:             break;
yading@10: 
yading@10:         case 's':
yading@10:             av_bprintf(new_line, "{\\fs}");
yading@10:             break;
yading@10:         }
yading@10:         tags[i].key = 0;
yading@10:     }
yading@10: }
yading@10: 
yading@10: static int microdvd_decode_frame(AVCodecContext *avctx,
yading@10:                                  void *data, int *got_sub_ptr, AVPacket *avpkt)
yading@10: {
yading@10:     AVSubtitle *sub = data;
yading@10:     AVBPrint new_line;
yading@10:     char c;
yading@10:     char *decoded_sub;
yading@10:     char *line = avpkt->data;
yading@10:     char *end = avpkt->data + avpkt->size;
yading@10:     struct microdvd_tag tags[sizeof(MICRODVD_TAGS) - 1] = {{0}};
yading@10: 
yading@10:     if (avpkt->size <= 0)
yading@10:         return avpkt->size;
yading@10: 
yading@10:     /* To be removed later */
yading@10:     if (sscanf(line, "{%*d}{%*[0123456789]}%c", &c) == 1 &&
yading@10:         line[avpkt->size - 1] == '\n') {
yading@10:         av_log(avctx, AV_LOG_ERROR, "AVPacket is not clean (contains timing "
yading@10:                "information and a trailing line break). You need to upgrade "
yading@10:                "your libavformat or sanitize your packet.\n");
yading@10:         return AVERROR_INVALIDDATA;
yading@10:     }
yading@10: 
yading@10:     av_bprint_init(&new_line, 0, 2048);
yading@10: 
yading@10:     // subtitle content
yading@10:     while (line < end && *line) {
yading@10: 
yading@10:         // parse MicroDVD tags, and open them in ASS
yading@10:         line = microdvd_load_tags(tags, line);
yading@10:         microdvd_open_tags(&new_line, tags);
yading@10: 
yading@10:         // simple copy until EOL or forced carriage return
yading@10:         while (line < end && *line && *line != '|') {
yading@10:             av_bprint_chars(&new_line, *line, 1);
yading@10:             line++;
yading@10:         }
yading@10: 
yading@10:         // line split
yading@10:         if (line < end && *line == '|') {
yading@10:             microdvd_close_no_persistent_tags(&new_line, tags);
yading@10:             av_bprintf(&new_line, "\\N");
yading@10:             line++;
yading@10:         }
yading@10:     }
yading@10:     if (new_line.len) {
yading@10:         av_bprintf(&new_line, "\r\n");
yading@10: 
yading@10:     av_bprint_finalize(&new_line, &decoded_sub);
yading@10:     if (*decoded_sub) {
yading@10:         int64_t start    = avpkt->pts;
yading@10:         int64_t duration = avpkt->duration;
yading@10:         int ts_start     = av_rescale_q(start,    avctx->time_base, (AVRational){1,100});
yading@10:         int ts_duration  = duration != -1 ?
yading@10:                            av_rescale_q(duration, avctx->time_base, (AVRational){1,100}) : -1;
yading@10:         ff_ass_add_rect(sub, decoded_sub, ts_start, ts_duration, 0);
yading@10:     }
yading@10:     av_free(decoded_sub);
yading@10:     }
yading@10: 
yading@10:     *got_sub_ptr = sub->num_rects > 0;
yading@10:     return avpkt->size;
yading@10: }
yading@10: 
yading@10: static int microdvd_init(AVCodecContext *avctx)
yading@10: {
yading@10:     int i, sidx;
yading@10:     AVBPrint font_buf;
yading@10:     int font_size    = ASS_DEFAULT_FONT_SIZE;
yading@10:     int color        = ASS_DEFAULT_COLOR;
yading@10:     int bold         = ASS_DEFAULT_BOLD;
yading@10:     int italic       = ASS_DEFAULT_ITALIC;
yading@10:     int underline    = ASS_DEFAULT_UNDERLINE;
yading@10:     int alignment    = ASS_DEFAULT_ALIGNMENT;
yading@10:     struct microdvd_tag tags[sizeof(MICRODVD_TAGS) - 1] = {{0}};
yading@10: 
yading@10:     av_bprint_init(&font_buf, 0, AV_BPRINT_SIZE_AUTOMATIC);
yading@10:     av_bprintf(&font_buf, "%s", ASS_DEFAULT_FONT);
yading@10: 
yading@10:     if (avctx->extradata) {
yading@10:         microdvd_load_tags(tags, avctx->extradata);
yading@10:         for (i = 0; i < sizeof(MICRODVD_TAGS) - 1; i++) {
yading@10:             switch (av_tolower(tags[i].key)) {
yading@10:             case 'y':
yading@10:                 for (sidx = 0; sidx < sizeof(MICRODVD_STYLES) - 1; sidx++) {
yading@10:                     if (tags[i].data1 & (1 << sidx)) {
yading@10:                         switch (MICRODVD_STYLES[sidx]) {
yading@10:                         case 'i': italic    = 1; break;
yading@10:                         case 'b': bold      = 1; break;
yading@10:                         case 'u': underline = 1; break;
yading@10:                         }
yading@10:                     }
yading@10:                 }
yading@10:                 break;
yading@10: 
yading@10:             case 'c': color     = tags[i].data1; break;
yading@10:             case 's': font_size = tags[i].data1; break;
yading@10:             case 'p': alignment =             8; break;
yading@10: 
yading@10:             case 'f':
yading@10:                 av_bprint_clear(&font_buf);
yading@10:                 av_bprintf(&font_buf, "%.*s",
yading@10:                            tags[i].data_string_len, tags[i].data_string);
yading@10:                 break;
yading@10:             }
yading@10:         }
yading@10:     }
yading@10:     return ff_ass_subtitle_header(avctx, font_buf.str, font_size, color,
yading@10:                                   ASS_DEFAULT_BACK_COLOR, bold, italic,
yading@10:                                   underline, alignment);
yading@10: }
yading@10: 
yading@10: AVCodec ff_microdvd_decoder = {
yading@10:     .name         = "microdvd",
yading@10:     .long_name    = NULL_IF_CONFIG_SMALL("MicroDVD subtitle"),
yading@10:     .type         = AVMEDIA_TYPE_SUBTITLE,
yading@10:     .id           = AV_CODEC_ID_MICRODVD,
yading@10:     .init         = microdvd_init,
yading@10:     .decode       = microdvd_decode_frame,
yading@10: };