From 88caf34510d6055be7669f89184d970ec6010498 Mon Sep 17 00:00:00 2001
From: Michael Niedermayer <michaelni@gmx.at>
Date: Fri, 26 Sep 2008 19:42:21 +0000
Subject: [PATCH] ASS/SSA muxer.

Originally committed as revision 15430 to svn://svn.ffmpeg.org/ffmpeg/trunk
---
 libavformat/Makefile     |  1 +
 libavformat/allformats.c |  2 +-
 libavformat/assenc.c     | 92 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 94 insertions(+), 1 deletion(-)
 create mode 100644 libavformat/assenc.c

diff --git a/libavformat/Makefile b/libavformat/Makefile
index c5ff173233..1537a24aa6 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -22,6 +22,7 @@ OBJS-$(CONFIG_ASF_DEMUXER)               += asf.o asfcrypt.o riff.o
 OBJS-$(CONFIG_ASF_MUXER)                 += asf-enc.o riff.o
 OBJS-$(CONFIG_ASF_STREAM_MUXER)          += asf-enc.o riff.o
 OBJS-$(CONFIG_ASS_DEMUXER)               += assdec.o
+OBJS-$(CONFIG_ASS_MUXER)                 += assenc.o
 OBJS-$(CONFIG_AU_DEMUXER)                += au.o raw.o
 OBJS-$(CONFIG_AU_MUXER)                  += au.o
 OBJS-$(CONFIG_AVI_DEMUXER)               += avidec.o riff.o
diff --git a/libavformat/allformats.c b/libavformat/allformats.c
index d644879b77..41cdcfb316 100644
--- a/libavformat/allformats.c
+++ b/libavformat/allformats.c
@@ -59,7 +59,7 @@ void av_register_all(void)
     REGISTER_DEMUXER  (APC, apc);
     REGISTER_DEMUXER  (APE, ape);
     REGISTER_MUXDEMUX (ASF, asf);
-    REGISTER_DEMUXER  (ASS, ass);
+    REGISTER_MUXDEMUX (ASS, ass);
     REGISTER_MUXER    (ASF_STREAM, asf_stream);
     REGISTER_MUXDEMUX (AU, au);
     REGISTER_MUXDEMUX (AVI, avi);
diff --git a/libavformat/assenc.c b/libavformat/assenc.c
new file mode 100644
index 0000000000..d1b93e82ef
--- /dev/null
+++ b/libavformat/assenc.c
@@ -0,0 +1,92 @@
+/*
+ * SSA/ASS muxer
+ * Copyright (c) 2008 Michael Niedermayer
+ *
+ * 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"
+
+typedef struct ASSContext{
+    unsigned int extra_index;
+}ASSContext;
+
+static int write_header(AVFormatContext *s)
+{
+    ASSContext *ass = s->priv_data;
+    AVCodecContext *avctx= s->streams[0]->codec;
+    uint8_t *last= NULL;
+
+    if(s->nb_streams != 1 || avctx->codec_id != CODEC_ID_SSA){
+        av_log(s, AV_LOG_ERROR, "Exactly one ASS/SSA stream is needed.\n");
+        return -1;
+    }
+
+    while(ass->extra_index < avctx->extradata_size){
+        uint8_t *p  = avctx->extradata + ass->extra_index;
+        uint8_t *end= strchr(p, '\n');
+        if(!end) end= avctx->extradata + avctx->extradata_size;
+        else     end++;
+
+        put_buffer(s->pb, p, end-p);
+        ass->extra_index += end-p;
+
+        if(last && !memcmp(last, "[Events]", 8))
+            break;
+        last=p;
+    }
+
+    put_flush_packet(s->pb);
+
+    return 0;
+}
+
+static int write_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    put_buffer(s->pb, pkt->data, pkt->size);
+
+    put_flush_packet(s->pb);
+
+    return 0;
+}
+
+static int write_trailer(AVFormatContext *s)
+{
+    ASSContext *ass = s->priv_data;
+    AVCodecContext *avctx= s->streams[0]->codec;
+
+    put_buffer(s->pb, avctx->extradata      + ass->extra_index,
+                      avctx->extradata_size - ass->extra_index);
+
+    put_flush_packet(s->pb);
+
+    return 0;
+}
+
+AVOutputFormat ass_muxer = {
+    "ass",
+    NULL_IF_CONFIG_SMALL("SSA/ASS format"),
+    NULL,
+    "ass,ssa",
+    sizeof(ASSContext),
+    CODEC_ID_NONE,
+    CODEC_ID_NONE,
+    write_header,
+    write_packet,
+    write_trailer,
+    .flags = AVFMT_GLOBALHEADER | AVFMT_NOTIMESTAMPS
+};