2 in 1, an ASS and SSA demuxer.

Tested with -scodec copy on all ASS & SSA samples that i found on mphq (exactly 2).

Originally committed as revision 15422 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/Makefile

@@ -21,6 +21,7 @@ OBJS-$(CONFIG_APE_DEMUXER)               += ape.o
 OBJS-$(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_AU_DEMUXER)                += au.o raw.o
 OBJS-$(CONFIG_AU_MUXER)                  += au.o
 OBJS-$(CONFIG_AVI_DEMUXER)               += avidec.o riff.o

libavformat/allformats.c

@@ -59,6 +59,7 @@ void av_register_all(void)
     REGISTER_DEMUXER  (APC, apc);
     REGISTER_DEMUXER  (APE, ape);
     REGISTER_MUXDEMUX (ASF, asf);
+    REGISTER_DEMUXER  (ASS, ass);
     REGISTER_MUXER    (ASF_STREAM, asf_stream);
     REGISTER_MUXDEMUX (AU, au);
     REGISTER_MUXDEMUX (AVI, avi);

libavformat/assdec.c

@@ -0,0 +1,186 @@
+/*
+ * SSA/ASS demuxer
+ * 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"
+
+#define MAX_LINESIZE 2000
+
+typedef struct ASSContext{
+    uint8_t *event_buffer;
+    uint8_t **event;
+    unsigned int event_count;
+    unsigned int event_index;
+}ASSContext;
+
+static void get_line(ByteIOContext *s, char *buf, int maxlen)
+{
+    int i = 0;
+    char c;
+
+    do{
+        c = get_byte(s);
+        if (i < maxlen-1 && c != '\r')
+            buf[i++] = c;
+    }while(c != '\n' && c);
+
+    buf[i] = 0;
+}
+
+static int probe(AVProbeData *p)
+{
+    const char *header= "[Script Info]";
+
+    if(   !memcmp(p->buf  , header, strlen(header))
+       || !memcmp(p->buf+3, header, strlen(header)))
+        return AVPROBE_SCORE_MAX;
+
+    return 0;
+}
+
+static int read_close(AVFormatContext *s)
+{
+    ASSContext *ass = s->priv_data;
+
+    av_freep(&ass->event_buffer);
+    av_freep(&ass->event);
+
+    return 0;
+}
+
+static int64_t get_pts(const uint8_t *p)
+{
+    int hour, min, sec, hsec;
+
+    if(sscanf(p, "%*[^,],%d:%d:%d%*c%d", &hour, &min, &sec, &hsec) != 4)
+        return AV_NOPTS_VALUE;
+
+//    av_log(NULL, AV_LOG_ERROR, "%d %d %d %d %d [%s]\n", i, hour, min, sec, hsec, p);
+
+    min+= 60*hour;
+    sec+= 60*min;
+
+    return sec*100+hsec;
+}
+
+static int event_cmp(uint8_t **a, uint8_t **b)
+{
+    return get_pts(*a) - get_pts(*b);
+}
+
+static int read_header(AVFormatContext *s, AVFormatParameters *ap)
+{
+    int i, header_remaining;
+    ASSContext *ass = s->priv_data;
+    ByteIOContext *pb = s->pb;
+    AVStream *st;
+    int allocated[2]={0};
+    uint8_t *p, **dst[2]={0};
+    int pos[2]={0};
+
+    st = av_new_stream(s, 0);
+    if (!st)
+        return -1;
+    av_set_pts_info(st, 64, 1, 100);
+    st->codec->codec_type = CODEC_TYPE_SUBTITLE;
+    st->codec->codec_id= CODEC_ID_SSA;
+
+    header_remaining= INT_MAX;
+    dst[0] = &st->codec->extradata;
+    dst[1] = &ass->event_buffer;
+    while(!url_feof(pb)){
+        uint8_t line[MAX_LINESIZE];
+
+        get_line(pb, line, sizeof(line));
+
+        if(!memcmp(line, "[Events]", 8))
+            header_remaining= 2;
+        else if(line[0]=='[')
+            header_remaining= INT_MAX;
+
+        i= header_remaining==0;
+
+        if(i && get_pts(line) == AV_NOPTS_VALUE)
+            continue;
+
+        p = av_fast_realloc(*(dst[i]), &allocated[i], pos[i]+MAX_LINESIZE);
+        if(!p)
+            goto fail;
+        *(dst[i])= p;
+        memcpy(p + pos[i], line, strlen(line)+1);
+        pos[i] += strlen(line);
+        if(i) ass->event_count++;
+        else  header_remaining--;
+    }
+    st->codec->extradata_size= pos[0];
+
+    if(ass->event_count >= UINT_MAX / sizeof(*ass->event))
+        goto fail;
+
+    ass->event= av_malloc(ass->event_count * sizeof(*ass->event));
+    p= ass->event_buffer;
+    for(i=0; i<ass->event_count; i++){
+        ass->event[i]= p;
+        while(*p && *p != '\n')
+            p++;
+        *p++ = 0;
+    }
+
+    qsort(ass->event, ass->event_count, sizeof(*ass->event), event_cmp);
+
+    return 0;
+
+fail:
+    read_close(s);
+
+    return -1;
+}
+
+static int read_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    ASSContext *ass = s->priv_data;
+    uint8_t *p;
+
+    if(ass->event_index >= ass->event_count)
+        return AVERROR(EIO);
+
+    p= ass->event[ ass->event_index ];
+
+    av_new_packet(pkt, strlen(p));
+    pkt->flags |= PKT_FLAG_KEY;
+    pkt->pos= p - ass->event_buffer + s->streams[0]->codec->extradata_size;
+    pkt->pts= pkt->dts= get_pts(p);
+    memcpy(pkt->data, p, pkt->size);
+
+    ass->event_index++;
+
+    return 0;
+}
+
+AVInputFormat ass_demuxer = {
+    "ass",
+    NULL_IF_CONFIG_SMALL("SSA/ASS format"),
+    sizeof(ASSContext),
+    probe,
+    read_header,
+    read_packet,
+    read_close,
+//    read_seek,
+};