JACOsub demuxer, decoder and muxer.

1 files changed, 304 insertions, 0 deletions

diff --git a/libavformat/jacosubdec.c b/libavformat/jacosubdec.c
new file mode 100644
index 0000000000..30c4f636bd
--- /dev/null
+++ b/libavformat/jacosubdec.c
@@ -0,0 +1,304 @@
+/*
+ * 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
+ * JACOsub subtitle demuxer
+ * @see http://unicorn.us.com/jacosub/jscripts.html
+ * @todo Support P[ALETTE] directive.
+ */
+
+#include "avformat.h"
+#include "internal.h"
+#include "libavcodec/jacosub.h"
+#include "libavutil/avstring.h"
+#include "libavutil/bprint.h"
+#include "libavutil/intreadwrite.h"
+
+typedef struct {
+    char *line;         ///< null-terminated heap allocated subtitle line
+    int64_t pos;        ///< offset position
+    int start;          ///< timestamp start
+    int end;            ///< timestamp end
+} SubEntry;
+
+typedef struct {
+    int shift;
+    unsigned timeres;
+    SubEntry *subs;     ///< subtitles list
+    int nsub;           ///< number of subtitles
+    int sid;            ///< current subtitle
+} JACOsubContext;
+
+static int timed_line(const char *ptr)
+{
+    char c;
+    return (sscanf(ptr, "%*u:%*u:%*u.%*u %*u:%*u:%*u.%*u %c", &c) == 1 ||
+            sscanf(ptr, "@%*u @%*u %c",                       &c) == 1);
+}
+
+static int jacosub_probe(AVProbeData *p)
+{
+    const char *ptr     = p->buf;
+    const char *ptr_end = p->buf + p->buf_size;
+
+    if (AV_RB24(ptr) == 0xEFBBBF)
+        ptr += 3; /* skip UTF-8 BOM */
+
+    while (ptr < ptr_end) {
+        if (timed_line(ptr))
+            return AVPROBE_SCORE_MAX / 2;
+        while (jss_whitespace(*ptr))
+            ptr++;
+        ptr += strcspn(ptr, "\n") + 1;
+    }
+    return 0;
+}
+
+static const char * const cmds[] = {
+    "CLOCKPAUSE",
+    "DIRECTIVE",
+    "FONT",
+    "HRES",
+    "INCLUDE",
+    "PALETTE",
+    "QUANTIZE",
+    "RAMP",
+    "SHIFT",
+    "TIMERES",
+};
+
+static int get_jss_cmd(char k)
+{
+    int i;
+
+    k = av_toupper(k);
+    for (i = 0; i < FF_ARRAY_ELEMS(cmds); i++)
+        if (k == cmds[i][0])
+            return i;
+    return -1;
+}
+
+static int jacosub_read_close(AVFormatContext *s)
+{
+    int i;
+    JACOsubContext *jacosub = s->priv_data;
+
+    for (i = 0; i < jacosub->nsub; i++)
+        av_freep(&jacosub->subs[i].line);
+    jacosub->nsub = 0;
+    av_freep(&jacosub->subs);
+    return 0;
+}
+
+static const char *read_ts(JACOsubContext *jacosub, const char *buf,
+                           int *ts_start, int *ts_end)
+{
+    int len;
+    unsigned hs, ms, ss, fs; // hours, minutes, seconds, frame start
+    unsigned he, me, se, fe; // hours, minutes, seconds, frame end
+
+    /* timed format */
+    if (sscanf(buf, "%u:%u:%u.%u %u:%u:%u.%u %n",
+               &hs, &ms, &ss, &fs,
+               &he, &me, &se, &fe, &len) == 8) {
+        *ts_start = (hs*3600 + ms*60 + ss) * jacosub->timeres + fs;
+        *ts_end   = (he*3600 + me*60 + se) * jacosub->timeres + fe;
+        goto shift_and_ret;
+    }
+
+    /* timestamps format */
+    if (sscanf(buf, "@%u @%u %n", ts_start, ts_end, &len) == 2)
+        goto shift_and_ret;
+
+    return NULL;
+
+shift_and_ret:
+    *ts_start = (*ts_start + jacosub->shift) * 100 / jacosub->timeres;
+    *ts_end   = (*ts_end   + jacosub->shift) * 100 / jacosub->timeres;
+    return buf + len;
+}
+
+static int get_shift(int timeres, const char *buf)
+{
+    int sign = 1;
+    int a = 0, b = 0, c = 0, d = 0;
+#define SSEP "%*1[.:]"
+    int n = sscanf(buf, "%d"SSEP"%d"SSEP"%d"SSEP"%d", &a, &b, &c, &d);
+#undef SSEP
+
+    if (*buf == '-' || a < 0) {
+        sign = -1;
+        a = FFABS(a);
+    }
+
+    switch (n) {
+    case 4: return sign * ((a*3600 + b*60 + c) * timeres + d);
+    case 3: return sign * ((         a*60 + b) * timeres + c);
+    case 2: return sign * ((                a) * timeres + b);
+    }
+
+    return 0;
+}
+
+static int cmp_timed_sub(const void *a, const void *b)
+{
+    return ((const SubEntry*)a)->start - ((const SubEntry*)b)->start;
+}
+
+static int jacosub_read_header(AVFormatContext *s)
+{
+    AVBPrint header;
+    AVIOContext *pb = s->pb;
+    char line[JSS_MAX_LINESIZE];
+    JACOsubContext *jacosub = s->priv_data;
+    int shift_set = 0; // only the first shift matters
+    int merge_line = 0;
+    int i;
+
+    AVStream *st = avformat_new_stream(s, NULL);
+    if (!st)
+        return AVERROR(ENOMEM);
+    avpriv_set_pts_info(st, 64, 1, 100);
+    st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
+    st->codec->codec_id   = CODEC_ID_JACOSUB;
+
+    jacosub->timeres = 30;
+
+    av_bprint_init(&header, 1024+FF_INPUT_BUFFER_PADDING_SIZE, 4096);
+
+    while (!url_feof(pb)) {
+        int cmd_len;
+        const char *p = line;
+        int64_t pos = avio_tell(pb);
+
+        ff_get_line(pb, line, sizeof(line));
+
+        p = jss_skip_whitespace(p);
+
+        /* queue timed line */
+        if (merge_line || timed_line(p)) {
+            SubEntry *subs, *sub;
+            const int len = strlen(line);
+
+            if (merge_line) {
+                char *tmp;
+                const int old_len = strlen(sub->line);
+
+                sub = &subs[jacosub->nsub];
+                tmp = av_realloc(sub->line, old_len + len + 1);
+                if (!tmp)
+                    return AVERROR(ENOMEM);
+                sub->line = tmp;
+                strcpy(sub->line + old_len, line);
+            } else {
+                subs = av_realloc(jacosub->subs,
+                                  sizeof(*jacosub->subs) * (jacosub->nsub+1));
+                if (!subs)
+                    return AVERROR(ENOMEM);
+                jacosub->subs = subs;
+                sub = &subs[jacosub->nsub];
+                sub->pos  = pos;
+                sub->line = av_strdup(line);
+                if (!sub->line)
+                    return AVERROR(ENOMEM);
+            }
+            merge_line = len > 1 && !strcmp(&line[len - 2], "\\\n");
+            if (!merge_line)
+                jacosub->nsub++;
+            continue;
+        }
+
+        /* skip all non-compiler commands and focus on the command */
+        if (*p != '#')
+            continue;
+        p++;
+        i = get_jss_cmd(p[0]);
+        if (i == -1)
+            continue;
+
+        /* trim command + spaces */
+        cmd_len = strlen(cmds[i]);
+        if (av_strncasecmp(p, cmds[i], cmd_len) == 0)
+            p += cmd_len;
+        else
+            p++;
+        p = jss_skip_whitespace(p);
+
+        /* handle commands which affect the whole script */
+        switch (cmds[i][0]) {
+        case 'S': // SHIFT command affect the whole script...
+            if (!shift_set) {
+                jacosub->shift = get_shift(jacosub->timeres, p);
+                shift_set = 1;
+            }
+            av_bprintf(&header, "#S %s", p);
+            break;
+        case 'T': // ...but must be placed after TIMERES
+            jacosub->timeres = strtol(p, NULL, 10);
+            av_bprintf(&header, "#T %s", p);
+            break;
+        }
+    }
+
+    /* general/essential directives in the extradata */
+    av_bprint_finalize(&header, (char **)&st->codec->extradata);
+    st->codec->extradata_size = header.len + 1;
+
+    /* SHIFT and TIMERES affect the whole script so packet timing can only be
+     * done in a second pass */
+    for (i = 0; i < jacosub->nsub; i++) {
+        SubEntry *sub = &jacosub->subs[i];
+        read_ts(jacosub, sub->line, &sub->start, &sub->end);
+    }
+    qsort(jacosub->subs, jacosub->nsub, sizeof(*jacosub->subs), cmp_timed_sub);
+
+    return 0;
+}
+
+static int jacosub_read_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    int res;
+    JACOsubContext *jacosub = s->priv_data;
+    const SubEntry *sub = &jacosub->subs[jacosub->sid++];
+
+    if (jacosub->sid == jacosub->nsub)
+        return AVERROR_EOF;
+    res = av_new_packet(pkt, strlen(sub->line));
+    if (res)
+        return res;
+    strcpy(pkt->data, sub->line);
+    pkt->flags |= AV_PKT_FLAG_KEY;
+    pkt->pos = sub->pos;
+    pkt->pts = pkt->dts = sub->start;
+    pkt->duration = sub->end - sub->start;
+    return 0;
+}
+
+AVInputFormat ff_jacosub_demuxer = {
+    .name           = "jacosub",
+    .long_name      = NULL_IF_CONFIG_SMALL("JACOsub subtitle format"),
+    .priv_data_size = sizeof(JACOsubContext),
+    .read_probe     = jacosub_probe,
+    .read_header    = jacosub_read_header,
+    .read_packet    = jacosub_read_packet,
+    .read_close     = jacosub_read_close,
+    .flags          = AVFMT_GENERIC_INDEX,
+};