SubViewer demuxer and decoder.

1 files changed, 78 insertions, 0 deletions

diff --git a/libavcodec/subviewerdec.c b/libavcodec/subviewerdec.c
new file mode 100644
index 0000000000..8a9f642703
--- /dev/null
+++ b/libavcodec/subviewerdec.c
@@ -0,0 +1,78 @@
+/*
+ * 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
+ * SubViewer subtitle decoder
+ * @see https://en.wikipedia.org/wiki/SubViewer
+ */
+
+#include "avcodec.h"
+#include "ass.h"
+#include "libavutil/bprint.h"
+
+static int subviewer_event_to_ass(AVBPrint *buf, const char *p)
+{
+    while (*p) {
+        char c;
+
+        if (sscanf(p, "%*u:%*u:%*u.%*u,%*u:%*u:%*u.%*u%c", &c) == 1)
+            p += strcspn(p, "\n") + 1;
+        if (!strncmp(p, "[br]", 4)) {
+            av_bprintf(buf, "\\N");
+            p += 4;
+        } else {
+            if (p[0] == '\n' && p[1])
+                av_bprintf(buf, "\\N");
+            else if (*p != '\r')
+                av_bprint_chars(buf, *p, 1);
+            p++;
+        }
+    }
+
+    av_bprintf(buf, "\r\n");
+    return 0;
+}
+
+static int subviewer_decode_frame(AVCodecContext *avctx,
+                                  void *data, int *got_sub_ptr, AVPacket *avpkt)
+{
+    AVSubtitle *sub = data;
+    const char *ptr = avpkt->data;
+    AVBPrint buf;
+
+    av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED);
+    // note: no need to rescale pts & duration since they are in the same
+    // timebase as ASS (1/100)
+    if (ptr && avpkt->size > 0 && !subviewer_event_to_ass(&buf, ptr))
+        ff_ass_add_rect(sub, buf.str, avpkt->pts, avpkt->duration, 0);
+    *got_sub_ptr = sub->num_rects > 0;
+    av_bprint_finalize(&buf, NULL);
+    return avpkt->size;
+}
+
+AVCodec ff_subviewer_decoder = {
+    .name           = "subviewer",
+    .long_name      = NULL_IF_CONFIG_SMALL("SubViewer subtitle"),
+    .type           = AVMEDIA_TYPE_SUBTITLE,
+    .id             = CODEC_ID_SUBVIEWER,
+    .decode         = subviewer_decode_frame,
+    .init           = ff_ass_subtitle_header_default,
+};