diff options
Diffstat (limited to 'libavcodec/microdvddec.c')
| -rw-r--r-- | libavcodec/microdvddec.c | 377 |
1 files changed, 377 insertions, 0 deletions
diff --git a/libavcodec/microdvddec.c b/libavcodec/microdvddec.c new file mode 100644 index 0000000000..f3c640f932 --- /dev/null +++ b/libavcodec/microdvddec.c @@ -0,0 +1,377 @@ +/* + * 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': + if (*s == '$') + s++; + 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 >= 0; 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 c; + char *decoded_sub; + char *line = avpkt->data; + char *end = avpkt->data + avpkt->size; + struct microdvd_tag tags[sizeof(MICRODVD_TAGS) - 1] = {{0}}; + + if (avpkt->size <= 0) + return avpkt->size; + + /* To be removed later */ + if (sscanf(line, "{%*d}{%*[0123456789]}%c", &c) == 1 && + line[avpkt->size - 1] == '\n') { + av_log(avctx, AV_LOG_ERROR, "AVPacket is not clean (contains timing " + "information and a trailing line break). You need to upgrade " + "your libavformat or sanitize your packet.\n"); + return AVERROR_INVALIDDATA; + } + + av_bprint_init(&new_line, 0, 2048); + + // 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++; + } + } + if (new_line.len) { + av_bprintf(&new_line, "\r\n"); + + av_bprint_finalize(&new_line, &decoded_sub); + if (*decoded_sub) { + int64_t start = avpkt->pts; + int64_t duration = avpkt->duration; + int ts_start = av_rescale_q(start, avctx->time_base, (AVRational){1,100}); + int ts_duration = duration != -1 ? + av_rescale_q(duration, avctx->time_base, (AVRational){1,100}) : -1; + ff_ass_add_rect(sub, decoded_sub, ts_start, ts_duration, 0); + } + av_free(decoded_sub); + } + + *got_sub_ptr = sub->num_rects > 0; + return avpkt->size; +} + +static int microdvd_init(AVCodecContext *avctx) +{ + int i, sidx; + AVBPrint font_buf; + int font_size = ASS_DEFAULT_FONT_SIZE; + int color = ASS_DEFAULT_COLOR; + int bold = ASS_DEFAULT_BOLD; + int italic = ASS_DEFAULT_ITALIC; + int underline = ASS_DEFAULT_UNDERLINE; + int alignment = ASS_DEFAULT_ALIGNMENT; + struct microdvd_tag tags[sizeof(MICRODVD_TAGS) - 1] = {{0}}; + + av_bprint_init(&font_buf, 0, AV_BPRINT_SIZE_AUTOMATIC); + av_bprintf(&font_buf, "%s", ASS_DEFAULT_FONT); + + if (avctx->extradata) { + microdvd_load_tags(tags, avctx->extradata); + for (i = 0; i < sizeof(MICRODVD_TAGS) - 1; i++) { + switch (av_tolower(tags[i].key)) { + case 'y': + for (sidx = 0; sidx < sizeof(MICRODVD_STYLES) - 1; sidx++) { + if (tags[i].data1 & (1 << sidx)) { + switch (MICRODVD_STYLES[sidx]) { + case 'i': italic = 1; break; + case 'b': bold = 1; break; + case 'u': underline = 1; break; + } + } + } + break; + + case 'c': color = tags[i].data1; break; + case 's': font_size = tags[i].data1; break; + case 'p': alignment = 8; break; + + case 'f': + av_bprint_clear(&font_buf); + av_bprintf(&font_buf, "%.*s", + tags[i].data_string_len, tags[i].data_string); + break; + } + } + } + return ff_ass_subtitle_header(avctx, font_buf.str, font_size, color, + ASS_DEFAULT_BACK_COLOR, bold, italic, + underline, alignment); +} + +AVCodec ff_microdvd_decoder = { + .name = "microdvd", + .long_name = NULL_IF_CONFIG_SMALL("MicroDVD subtitle"), + .type = AVMEDIA_TYPE_SUBTITLE, + .id = AV_CODEC_ID_MICRODVD, + .init = microdvd_init, + .decode = microdvd_decode_frame, +}; |