--- /dev/null
+/*
+ * Copyright (c) 2012 Clément Bœsch
+ *
+ * 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
+ */
+
+/**
+ * @file
+ * MicroDVD subtitle decoder
+ *
+ * Based on the specifications found here:
+ * https://trac.videolan.org/vlc/ticket/1825#comment:6
+ */
+
+#include "libavutil/avstring.h"
+#include "libavutil/parseutils.h"
+#include "libavutil/bprint.h"
+#include "avcodec.h"
+#include "ass.h"
+
+static int indexof(const char *s, int c)
+{
+ char *f = strchr(s, c);
+ return f ? (f - s) : -1;
+}
+
+struct microdvd_tag {
+ char key;
+ int persistent;
+ uint32_t data1;
+ uint32_t data2;
+ char *data_string;
+ int data_string_len;
+};
+
+#define MICRODVD_PERSISTENT_OFF 0
+#define MICRODVD_PERSISTENT_ON 1
+#define MICRODVD_PERSISTENT_OPENED 2
+
+// Color, Font, Size, cHarset, stYle, Position, cOordinate
+#define MICRODVD_TAGS "cfshyYpo"
+
+static void microdvd_set_tag(struct microdvd_tag *tags, struct microdvd_tag tag)
+{
+ int tag_index = indexof(MICRODVD_TAGS, tag.key);
+
+ if (tag_index < 0)
+ return;
+ memcpy(&tags[tag_index], &tag, sizeof(tag));
+}
+
+// italic, bold, underline, strike-through
+#define MICRODVD_STYLES "ibus"
+
+static char *microdvd_load_tags(struct microdvd_tag *tags, char *s)
+{
+ while (*s == '{') {
+ char *start = s;
+ char tag_char = *(s + 1);
+ struct microdvd_tag tag = {0};
+
+ if (!tag_char || *(s + 2) != ':')
+ break;
+ s += 3;
+
+ switch (tag_char) {
+
+ /* Style */
+ case 'Y':
+ tag.persistent = MICRODVD_PERSISTENT_ON;
+ case 'y':
+ while (*s && *s != '}') {
+ int style_index = indexof(MICRODVD_STYLES, *s);
+
+ if (style_index >= 0)
+ tag.data1 |= (1 << style_index);
+ s++;
+ }
+ if (*s != '}')
+ break;
+ /* We must distinguish persistent and non-persistent styles
+ * to handle this kind of style tags: {y:ib}{Y:us} */
+ tag.key = tag_char;
+ break;
+
+ /* Color */
+ case 'C':
+ tag.persistent = MICRODVD_PERSISTENT_ON;
+ case 'c':
+ tag.data1 = strtol(s, &s, 16) & 0x00ffffff;
+ if (*s != '}')
+ break;
+ tag.key = 'c';
+ break;
+
+ /* Font name */
+ case 'F':
+ tag.persistent = MICRODVD_PERSISTENT_ON;
+ case 'f': {
+ int len = indexof(s, '}');
+ if (len < 0)
+ break;
+ tag.data_string = s;
+ tag.data_string_len = len;
+ s += len;
+ tag.key = 'f';
+ break;
+ }
+
+ /* Font size */
+ case 'S':
+ tag.persistent = MICRODVD_PERSISTENT_ON;
+ case 's':
+ tag.data1 = strtol(s, &s, 10);
+ if (*s != '}')
+ break;
+ tag.key = 's';
+ break;
+
+ /* Charset */
+ case 'H': {
+ //TODO: not yet handled, just parsed.
+ int len = indexof(s, '}');
+ if (len < 0)
+ break;
+ tag.data_string = s;
+ tag.data_string_len = len;
+ s += len;
+ tag.key = 'h';
+ break;
+ }
+
+ /* Position */
+ case 'P':
+ tag.persistent = MICRODVD_PERSISTENT_ON;
+ tag.data1 = (*s++ == '1');
+ if (*s != '}')
+ break;
+ tag.key = 'p';
+ break;
+
+ /* Coordinates */
+ case 'o':
+ tag.persistent = MICRODVD_PERSISTENT_ON;
+ tag.data1 = strtol(s, &s, 10);
+ if (*s != ',')
+ break;
+ s++;
+ tag.data2 = strtol(s, &s, 10);
+ if (*s != '}')
+ break;
+ tag.key = 'o';
+ break;
+
+ default: /* Unknown tag, we consider it's text */
+ break;
+ }
+
+ if (tag.key == 0)
+ return start;
+
+ microdvd_set_tag(tags, tag);
+ s++;
+ }
+ return s;
+}
+
+static void microdvd_open_tags(AVBPrint *new_line, struct microdvd_tag *tags)
+{
+ int i, sidx;
+ for (i = 0; i < sizeof(MICRODVD_TAGS) - 1; i++) {
+ if (tags[i].persistent == MICRODVD_PERSISTENT_OPENED)
+ continue;
+ switch (tags[i].key) {
+ case 'Y':
+ case 'y':
+ for (sidx = 0; sidx < sizeof(MICRODVD_STYLES) - 1; sidx++)
+ if (tags[i].data1 & (1 << sidx))
+ av_bprintf(new_line, "{\\%c1}", MICRODVD_STYLES[sidx]);
+ break;
+
+ case 'c':
+ av_bprintf(new_line, "{\\c&H%06X&}", tags[i].data1);
+ break;
+
+ case 'f':
+ av_bprintf(new_line, "{\\fn%.*s}",
+ tags[i].data_string_len, tags[i].data_string);
+ break;
+
+ case 's':
+ av_bprintf(new_line, "{\\fs%d}", tags[i].data1);
+ break;
+
+ case 'p':
+ if (tags[i].data1 == 0)
+ av_bprintf(new_line, "{\\an8}");
+ break;
+
+ case 'o':
+ av_bprintf(new_line, "{\\pos(%d,%d)}",
+ tags[i].data1, tags[i].data2);
+ break;
+ }
+ if (tags[i].persistent == MICRODVD_PERSISTENT_ON)
+ tags[i].persistent = MICRODVD_PERSISTENT_OPENED;
+ }
+}
+
+static void microdvd_close_no_persistent_tags(AVBPrint *new_line,
+ struct microdvd_tag *tags)
+{
+ int i, sidx;
+
+ for (i = sizeof(MICRODVD_TAGS) - 2; i; i--) {
+ if (tags[i].persistent != MICRODVD_PERSISTENT_OFF)
+ continue;
+ switch (tags[i].key) {
+
+ case 'y':
+ for (sidx = sizeof(MICRODVD_STYLES) - 2; sidx >= 0; sidx--)
+ if (tags[i].data1 & (1 << sidx))
+ av_bprintf(new_line, "{\\%c0}", MICRODVD_STYLES[sidx]);
+ break;
+
+ case 'c':
+ av_bprintf(new_line, "{\\c}");
+ break;
+
+ case 'f':
+ av_bprintf(new_line, "{\\fn}");
+ break;
+
+ case 's':
+ av_bprintf(new_line, "{\\fs}");
+ break;
+ }
+ tags[i].key = 0;
+ }
+}
+
+static int microdvd_decode_frame(AVCodecContext *avctx,
+ void *data, int *got_sub_ptr, AVPacket *avpkt)
+{
+ AVSubtitle *sub = data;
+ AVBPrint new_line;
+ char *decoded_sub;
+ char *line = avpkt->data;
+ char *end = avpkt->data + avpkt->size;
+ int64_t frame_start = avpkt->pts;
+ int64_t frame_end = avpkt->pts + avpkt->duration;
+ int ts_start = av_rescale_q(frame_start, avctx->time_base, (AVRational){1,100});
+ int ts_end = av_rescale_q(frame_end, avctx->time_base, (AVRational){1,100});
+ struct microdvd_tag tags[sizeof(MICRODVD_TAGS) - 1] = {{0}};
+
+ if (avpkt->size <= 0)
+ return avpkt->size;
+
+ av_bprint_init(&new_line, 0, 2048);
+
+ // skip {frame_start}{frame_end}
+ line = strchr(line, '}'); if (!line) goto end; line++;
+ line = strchr(line, '}'); if (!line) goto end; line++;
+
+ // subtitle content
+ while (line < end && *line) {
+
+ // parse MicroDVD tags, and open them in ASS
+ line = microdvd_load_tags(tags, line);
+ microdvd_open_tags(&new_line, tags);
+
+ // simple copy until EOL or forced carriage return
+ while (line < end && *line && *line != '|') {
+ av_bprint_chars(&new_line, *line, 1);
+ line++;
+ }
+
+ // line split
+ if (line < end && *line == '|') {
+ microdvd_close_no_persistent_tags(&new_line, tags);
+ av_bprintf(&new_line, "\\N");
+ line++;
+ }
+ }
+
+end:
+ av_bprint_finalize(&new_line, &decoded_sub);
+ if (*decoded_sub)
+ ff_ass_add_rect(sub, decoded_sub, ts_start, ts_end, 0);
+ av_free(decoded_sub);
+
+ *got_sub_ptr = sub->num_rects > 0;
+ return avpkt->size;
+}
+
+AVCodec ff_microdvd_decoder = {
+ .name = "microdvd",
+ .long_name = NULL_IF_CONFIG_SMALL("MicroDVD subtitle"),
+ .type = AVMEDIA_TYPE_SUBTITLE,
+ .id = CODEC_ID_MICRODVD,
+ .init = ff_ass_subtitle_header_default,
+ .decode = microdvd_decode_frame,
+};