add SubRip muxer and demuxer

Originally committed as revision 24488 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 102 insertions, 0 deletions

diff --git a/libavformat/srtdec.c b/libavformat/srtdec.c
new file mode 100644
index 0000000000..104031a422
--- /dev/null
+++ b/libavformat/srtdec.c
@@ -0,0 +1,102 @@
+/*
+ * SubRip subtitle demuxer
+ * Copyright (c) 2010  Aurelien Jacobs <aurel@gnuage.org>
+ *
+ * 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
+ */
+
+#include "avformat.h"
+#include "internal.h"
+#include "libavutil/intreadwrite.h"
+
+static int srt_probe(AVProbeData *p)
+{
+    unsigned char *ptr = p->buf;
+    int i, v, num = 0;
+
+    if (AV_RB24(ptr) == 0xEFBBBF)
+        ptr += 3;  /* skip UTF-8 BOM */
+
+    for (i=0; i<2; i++) {
+        if (num == i && sscanf(ptr, "%*d:%*2d:%*2d%*1[,.]%*3d --> %*d:%*2d:%*2d%*1[,.]%3d", &v) == 1)
+            return AVPROBE_SCORE_MAX;
+        num = atoi(ptr);
+        ptr += strcspn(ptr, "\n") + 1;
+    }
+    return 0;
+}
+
+static int srt_read_header(AVFormatContext *s, AVFormatParameters *ap)
+{
+    AVStream *st = av_new_stream(s, 0);
+    if (!st)
+        return -1;
+    av_set_pts_info(st, 64, 1, 1000);
+    st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
+    st->codec->codec_id   = CODEC_ID_SRT;
+    return 0;
+}
+
+static int64_t get_pts(const char *buf)
+{
+    int i, v, hour, min, sec, hsec;
+
+    for (i=0; i<2; i++) {
+        if (sscanf(buf, "%d:%2d:%2d%*1[,.]%3d --> %*d:%*2d:%*2d%*1[,.]%3d",
+                   &hour, &min, &sec, &hsec, &v) == 5) {
+            min += 60*hour;
+            sec += 60*min;
+            return sec*1000+hsec;
+        }
+        buf += strcspn(buf, "\n") + 1;
+    }
+    return AV_NOPTS_VALUE;
+}
+
+static inline int is_eol(char c)
+{
+    return c == '\r' || c == '\n';
+}
+
+static int srt_read_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    char buffer[2048], *ptr = buffer, *ptr2;
+    int64_t pos = url_ftell(s->pb);
+    int res = AVERROR_EOF;
+
+    do {
+        ptr2 = ptr;
+        ptr += ff_get_line(s->pb, ptr, sizeof(buffer)+buffer-ptr);
+    } while (!is_eol(*ptr2) && !url_feof(s->pb) && ptr-buffer<sizeof(buffer)-1);
+
+    if (buffer[0] && !(res = av_new_packet(pkt, ptr-buffer))) {
+        memcpy(pkt->data, buffer, pkt->size);
+        pkt->flags |= AV_PKT_FLAG_KEY;
+        pkt->pos = pos;
+        pkt->pts = pkt->dts = get_pts(pkt->data);
+    }
+    return res;
+}
+
+AVInputFormat srt_demuxer = {
+    .name        = "srt",
+    .long_name   = NULL_IF_CONFIG_SMALL("SubRip subtitle format"),
+    .read_probe  = srt_probe,
+    .read_header = srt_read_header,
+    .read_packet = srt_read_packet,
+    .flags       = AVFMT_GENERIC_INDEX,
+};