1/*
2 * Copyright (c) 2012 Cl��ment B��sch
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21/**
22 * @file
23 * JACOsub subtitle demuxer
24 * @see http://unicorn.us.com/jacosub/jscripts.html
25 * @todo Support P[ALETTE] directive.
26 */
27
28#include "avformat.h"
29#include "internal.h"
30#include "subtitles.h"
31#include "libavcodec/internal.h"
32#include "libavcodec/jacosub.h"
33#include "libavutil/avstring.h"
34#include "libavutil/bprint.h"
35#include "libavutil/intreadwrite.h"
36
37typedef struct {
38    int shift;
39    unsigned timeres;
40    FFDemuxSubtitlesQueue q;
41} JACOsubContext;
42
43static int timed_line(const char *ptr)
44{
45    char c;
46    int fs, fe;
47    return (sscanf(ptr, "%*u:%*u:%*u.%*u %*u:%*u:%*u.%*u %c", &c) == 1 ||
48            (sscanf(ptr, "@%u @%u %c", &fs, &fe, &c) == 3 && fs < fe));
49}
50
51static int jacosub_probe(AVProbeData *p)
52{
53    const char *ptr     = p->buf;
54    const char *ptr_end = p->buf + p->buf_size;
55
56    if (AV_RB24(ptr) == 0xEFBBBF)
57        ptr += 3; /* skip UTF-8 BOM */
58
59    while (ptr < ptr_end) {
60        while (jss_whitespace(*ptr))
61            ptr++;
62        if (*ptr != '#' && *ptr != '\n') {
63            if (timed_line(ptr))
64                return AVPROBE_SCORE_EXTENSION + 1;
65            return 0;
66        }
67        ptr += ff_subtitles_next_line(ptr);
68    }
69    return 0;
70}
71
72static const char * const cmds[] = {
73    "CLOCKPAUSE",
74    "DIRECTIVE",
75    "FONT",
76    "HRES",
77    "INCLUDE",
78    "PALETTE",
79    "QUANTIZE",
80    "RAMP",
81    "SHIFT",
82    "TIMERES",
83};
84
85static int get_jss_cmd(char k)
86{
87    int i;
88
89    k = av_toupper(k);
90    for (i = 0; i < FF_ARRAY_ELEMS(cmds); i++)
91        if (k == cmds[i][0])
92            return i;
93    return -1;
94}
95
96static int jacosub_read_close(AVFormatContext *s)
97{
98    JACOsubContext *jacosub = s->priv_data;
99    ff_subtitles_queue_clean(&jacosub->q);
100    return 0;
101}
102
103static const char *read_ts(JACOsubContext *jacosub, const char *buf,
104                           int64_t *start, int *duration)
105{
106    int len;
107    unsigned hs, ms, ss, fs; // hours, minutes, seconds, frame start
108    unsigned he, me, se, fe; // hours, minutes, seconds, frame end
109    int ts_start, ts_end;
110
111    /* timed format */
112    if (sscanf(buf, "%u:%u:%u.%u %u:%u:%u.%u %n",
113               &hs, &ms, &ss, &fs,
114               &he, &me, &se, &fe, &len) == 8) {
115        ts_start = (hs*3600 + ms*60 + ss) * jacosub->timeres + fs;
116        ts_end   = (he*3600 + me*60 + se) * jacosub->timeres + fe;
117        goto shift_and_ret;
118    }
119
120    /* timestamps format */
121    if (sscanf(buf, "@%u @%u %n", &ts_start, &ts_end, &len) == 2)
122        goto shift_and_ret;
123
124    return NULL;
125
126shift_and_ret:
127    ts_start  = (ts_start + jacosub->shift) * 100 / jacosub->timeres;
128    ts_end    = (ts_end   + jacosub->shift) * 100 / jacosub->timeres;
129    *start    = ts_start;
130    *duration = ts_start + ts_end;
131    return buf + len;
132}
133
134static int get_shift(int timeres, const char *buf)
135{
136    int sign = 1;
137    int a = 0, b = 0, c = 0, d = 0;
138#define SSEP "%*1[.:]"
139    int n = sscanf(buf, "%d"SSEP"%d"SSEP"%d"SSEP"%d", &a, &b, &c, &d);
140#undef SSEP
141
142    if (*buf == '-' || a < 0) {
143        sign = -1;
144        a = FFABS(a);
145    }
146
147    switch (n) {
148    case 4: return sign * ((a*3600 + b*60 + c) * timeres + d);
149    case 3: return sign * ((         a*60 + b) * timeres + c);
150    case 2: return sign * ((                a) * timeres + b);
151    }
152
153    return 0;
154}
155
156static int jacosub_read_header(AVFormatContext *s)
157{
158    AVBPrint header;
159    AVIOContext *pb = s->pb;
160    char line[JSS_MAX_LINESIZE];
161    JACOsubContext *jacosub = s->priv_data;
162    int shift_set = 0; // only the first shift matters
163    int merge_line = 0;
164    int i, ret;
165
166    AVStream *st = avformat_new_stream(s, NULL);
167    if (!st)
168        return AVERROR(ENOMEM);
169    avpriv_set_pts_info(st, 64, 1, 100);
170    st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
171    st->codec->codec_id   = AV_CODEC_ID_JACOSUB;
172
173    jacosub->timeres = 30;
174
175    av_bprint_init(&header, 1024+FF_INPUT_BUFFER_PADDING_SIZE, 4096);
176
177    while (!url_feof(pb)) {
178        int cmd_len;
179        const char *p = line;
180        int64_t pos = avio_tell(pb);
181        int len = ff_get_line(pb, line, sizeof(line));
182
183        p = jss_skip_whitespace(p);
184
185        /* queue timed line */
186        if (merge_line || timed_line(p)) {
187            AVPacket *sub;
188
189            sub = ff_subtitles_queue_insert(&jacosub->q, line, len, merge_line);
190            if (!sub)
191                return AVERROR(ENOMEM);
192            sub->pos = pos;
193            merge_line = len > 1 && !strcmp(&line[len - 2], "\\\n");
194            continue;
195        }
196
197        /* skip all non-compiler commands and focus on the command */
198        if (*p != '#')
199            continue;
200        p++;
201        i = get_jss_cmd(p[0]);
202        if (i == -1)
203            continue;
204
205        /* trim command + spaces */
206        cmd_len = strlen(cmds[i]);
207        if (av_strncasecmp(p, cmds[i], cmd_len) == 0)
208            p += cmd_len;
209        else
210            p++;
211        p = jss_skip_whitespace(p);
212
213        /* handle commands which affect the whole script */
214        switch (cmds[i][0]) {
215        case 'S': // SHIFT command affect the whole script...
216            if (!shift_set) {
217                jacosub->shift = get_shift(jacosub->timeres, p);
218                shift_set = 1;
219            }
220            av_bprintf(&header, "#S %s", p);
221            break;
222        case 'T': // ...but must be placed after TIMERES
223            jacosub->timeres = strtol(p, NULL, 10);
224            if (!jacosub->timeres)
225                jacosub->timeres = 30;
226            else
227                av_bprintf(&header, "#T %s", p);
228            break;
229        }
230    }
231
232    /* general/essential directives in the extradata */
233    ret = avpriv_bprint_to_extradata(st->codec, &header);
234    if (ret < 0)
235        return ret;
236
237    /* SHIFT and TIMERES affect the whole script so packet timing can only be
238     * done in a second pass */
239    for (i = 0; i < jacosub->q.nb_subs; i++) {
240        AVPacket *sub = &jacosub->q.subs[i];
241        read_ts(jacosub, sub->data, &sub->pts, &sub->duration);
242    }
243    ff_subtitles_queue_finalize(&jacosub->q);
244
245    return 0;
246}
247
248static int jacosub_read_packet(AVFormatContext *s, AVPacket *pkt)
249{
250    JACOsubContext *jacosub = s->priv_data;
251    return ff_subtitles_queue_read_packet(&jacosub->q, pkt);
252}
253
254static int jacosub_read_seek(AVFormatContext *s, int stream_index,
255                             int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
256{
257    JACOsubContext *jacosub = s->priv_data;
258    return ff_subtitles_queue_seek(&jacosub->q, s, stream_index,
259                                   min_ts, ts, max_ts, flags);
260}
261
262AVInputFormat ff_jacosub_demuxer = {
263    .name           = "jacosub",
264    .long_name      = NULL_IF_CONFIG_SMALL("JACOsub subtitle format"),
265    .priv_data_size = sizeof(JACOsubContext),
266    .read_probe     = jacosub_probe,
267    .read_header    = jacosub_read_header,
268    .read_packet    = jacosub_read_packet,
269    .read_seek2     = jacosub_read_seek,
270    .read_close     = jacosub_read_close,
271};
272