RealText demuxer and decoder.

Changelog

@@ -17,6 +17,7 @@ version next:
 - showwaves filter
 - LucasArts SMUSH playback support
 - SAMI demuxer and decoder
+- RealText demuxer and decoder
 
 
 version 0.11:

doc/general.texi

@@ -864,6 +864,7 @@ performance on systems without hardware floating point support).
 @item JACOsub      @tab X @tab X @tab   @tab X
 @item MicroDVD     @tab X @tab X @tab   @tab X
 @item PGS          @tab   @tab   @tab   @tab X
+@item RealText     @tab   @tab X @tab   @tab X
 @item SAMI         @tab   @tab X @tab   @tab X
 @item SubRip (SRT) @tab X @tab X @tab X @tab X
 @item XSUB         @tab   @tab   @tab X @tab X

libavcodec/Makefile

@@ -379,6 +379,7 @@ OBJS-$(CONFIG_RA_288_DECODER)          += ra288.o celp_math.o celp_filters.o
 OBJS-$(CONFIG_RALF_DECODER)            += ralf.o
 OBJS-$(CONFIG_RAWVIDEO_DECODER)        += rawdec.o
 OBJS-$(CONFIG_RAWVIDEO_ENCODER)        += rawenc.o
+OBJS-$(CONFIG_REALTEXT_DECODER)        += realtextdec.o ass.o
 OBJS-$(CONFIG_RL2_DECODER)             += rl2.o
 OBJS-$(CONFIG_ROQ_DECODER)             += roqvideodec.o roqvideo.o
 OBJS-$(CONFIG_ROQ_ENCODER)             += roqvideoenc.o roqvideo.o elbg.o

libavcodec/allcodecs.c

@@ -405,6 +405,7 @@ void avcodec_register_all(void)
     REGISTER_DECODER (JACOSUB, jacosub);
     REGISTER_DECODER (MICRODVD, microdvd);
     REGISTER_DECODER (PGSSUB, pgssub);
+    REGISTER_DECODER (REALTEXT, realtext);
     REGISTER_DECODER (SAMI, sami);
     REGISTER_ENCDEC  (SRT, srt);
     REGISTER_ENCDEC  (XSUB, xsub);

libavcodec/avcodec.h

@@ -431,6 +431,7 @@ enum CodecID {
     CODEC_ID_EIA_608    = MKBETAG('c','6','0','8'),
     CODEC_ID_JACOSUB    = MKBETAG('J','S','U','B'),
     CODEC_ID_SAMI       = MKBETAG('S','A','M','I'),
+    CODEC_ID_REALTEXT   = MKBETAG('R','T','X','T'),
 
     /* other specific kind of codecs (generally used for attachments) */
     CODEC_ID_FIRST_UNKNOWN = 0x18000,           ///< A dummy ID pointing at the start of various fake codecs.

libavcodec/realtextdec.c

@@ -0,0 +1,83 @@
+/*
+ * 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
+ * RealText subtitle decoder
+ * @see http://service.real.com/help/library/guides/ProductionGuide/prodguide/htmfiles/realtext.htm
+ */
+
+#include "avcodec.h"
+#include "ass.h"
+#include "libavutil/avstring.h"
+#include "libavutil/bprint.h"
+
+static int rt_event_to_ass(AVBPrint *buf, const char *p)
+{
+    int prev_chr_is_space = 1;
+
+    while (*p) {
+        if (*p != '<') {
+            if (!isspace(*p))
+                av_bprint_chars(buf, *p, 1);
+            else if (!prev_chr_is_space)
+                av_bprint_chars(buf, ' ', 1);
+            prev_chr_is_space = isspace(*p);
+        } else {
+            const char *end = strchr(p, '>');
+            if (!end)
+                break;
+            if (!av_strncasecmp(p, "<br/>", 5) ||
+                !av_strncasecmp(p, "<br>",  4)) {
+                av_bprintf(buf, "\\N");
+            }
+            p = end;
+        }
+        p++;
+    }
+    av_bprintf(buf, "\r\n");
+    return 0;
+}
+
+static int realtext_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, 4096);
+    // note: no need to rescale pts & duration since they are in the same
+    // timebase than ASS (1/100)
+    if (ptr && avpkt->size > 0 && !rt_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_realtext_decoder = {
+    .name           = "realtext",
+    .long_name      = NULL_IF_CONFIG_SMALL("RealText subtitle"),
+    .type           = AVMEDIA_TYPE_SUBTITLE,
+    .id             = CODEC_ID_REALTEXT,
+    .decode         = realtext_decode_frame,
+    .init           = ff_ass_subtitle_header_default,
+};

libavcodec/version.h

@@ -27,7 +27,7 @@
  */
 
 #define LIBAVCODEC_VERSION_MAJOR 54
-#define LIBAVCODEC_VERSION_MINOR  30
+#define LIBAVCODEC_VERSION_MINOR  31
 #define LIBAVCODEC_VERSION_MICRO 100
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \

libavformat/Makefile

@@ -255,6 +255,7 @@ OBJS-$(CONFIG_QCP_DEMUXER)               += qcp.o
 OBJS-$(CONFIG_R3D_DEMUXER)               += r3d.o
 OBJS-$(CONFIG_RAWVIDEO_DEMUXER)          += rawvideodec.o rawdec.o
 OBJS-$(CONFIG_RAWVIDEO_MUXER)            += rawenc.o
+OBJS-$(CONFIG_REALTEXT_DEMUXER)          += realtextdec.o
 OBJS-$(CONFIG_RL2_DEMUXER)               += rl2.o
 OBJS-$(CONFIG_RM_DEMUXER)                += rmdec.o rm.o
 OBJS-$(CONFIG_RM_MUXER)                  += rmenc.o rm.o

libavformat/allformats.c

@@ -199,6 +199,7 @@ void av_register_all(void)
     REGISTER_DEMUXER  (QCP, qcp);
     REGISTER_DEMUXER  (R3D, r3d);
     REGISTER_MUXDEMUX (RAWVIDEO, rawvideo);
+    REGISTER_DEMUXER  (REALTEXT, realtext);
     REGISTER_DEMUXER  (RL2, rl2);
     REGISTER_MUXDEMUX (RM, rm);
     REGISTER_MUXDEMUX (ROQ, roq);

libavformat/realtextdec.c

@@ -0,0 +1,145 @@
+/*
+ * 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
+ * RealText subtitle demuxer
+ * @see http://service.real.com/help/library/guides/ProductionGuide/prodguide/htmfiles/realtext.htm
+ */
+
+#include "avformat.h"
+#include "internal.h"
+#include "subtitles.h"
+#include "libavutil/avstring.h"
+#include "libavutil/bprint.h"
+#include "libavutil/intreadwrite.h"
+
+typedef struct {
+    FFDemuxSubtitlesQueue q;
+} RealTextContext;
+
+static int realtext_probe(AVProbeData *p)
+{
+    const unsigned char *ptr = p->buf;
+
+    if (AV_RB24(ptr) == 0xEFBBBF)
+        ptr += 3;  /* skip UTF-8 BOM */
+    return !av_strncasecmp(ptr, "<window", 7) ? AVPROBE_SCORE_MAX/2 : 0;
+}
+
+static int read_ts(const char *s)
+{
+    int hh, mm, ss, ms;
+
+    if (sscanf(s, "%u:%u:%u.%u", &hh, &mm, &ss, &ms) == 4) return (hh*3600 + mm*60 + ss) * 100 + ms;
+    if (sscanf(s, "%u:%u:%u"   , &hh, &mm, &ss     ) == 3) return (hh*3600 + mm*60 + ss) * 100;
+    if (sscanf(s,    "%u:%u.%u",      &mm, &ss, &ms) == 3) return (          mm*60 + ss) * 100 + ms;
+    if (sscanf(s,    "%u:%u"   ,      &mm, &ss     ) == 2) return (          mm*60 + ss) * 100;
+    if (sscanf(s,       "%u.%u",           &ss, &ms) == 2) return (                  ss) * 100 + ms;
+    return strtol(s, NULL, 10) * 100;
+}
+
+static int realtext_read_header(AVFormatContext *s)
+{
+    RealTextContext *rt = s->priv_data;
+    AVStream *st = avformat_new_stream(s, NULL);
+    AVBPrint buf;
+    char c = 0;
+    int res = 0, duration = read_ts("60"); // default duration is 60 seconds
+
+    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_REALTEXT;
+
+    av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED);
+
+    while (!url_feof(s->pb)) {
+        AVPacket *sub;
+        const int64_t pos = avio_tell(s->pb) - (c != 0);
+        int n = ff_smil_extract_next_chunk(s->pb, &buf, &c);
+
+        if (n == 0)
+            break;
+
+        if (!av_strncasecmp(buf.str, "<window", 7)) {
+            /* save header to extradata */
+            const char *p = ff_smil_get_attr_ptr(buf.str, "duration");
+
+            if (p)
+                duration = read_ts(p);
+            st->codec->extradata = av_strdup(buf.str);
+            if (!st->codec->extradata) {
+                res = AVERROR(ENOMEM);
+                goto end;
+            }
+            st->codec->extradata_size = buf.len + 1;
+        } else {
+            /* if we just read a <time> tag, introduce a new event, otherwise merge
+             * with the previous one */
+            int merge = !av_strncasecmp(buf.str, "<time", 5) ? 0 : 1;
+            sub = ff_subtitles_queue_insert(&rt->q, buf.str, buf.len, merge);
+            if (!sub) {
+                res = AVERROR(ENOMEM);
+                goto end;
+            }
+            if (!merge) {
+                const char *begin = ff_smil_get_attr_ptr(buf.str, "begin");
+                const char *end   = ff_smil_get_attr_ptr(buf.str, "end");
+
+                sub->pos      = pos;
+                sub->pts      = begin ? read_ts(begin) : 0;
+                sub->duration = end ? (read_ts(end) - sub->pts) : duration;
+            }
+        }
+        av_bprint_clear(&buf);
+    }
+    ff_subtitles_queue_finalize(&rt->q);
+
+end:
+    av_bprint_finalize(&buf, NULL);
+    return res;
+}
+
+static int realtext_read_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    RealTextContext *rt = s->priv_data;
+    return ff_subtitles_queue_read_packet(&rt->q, pkt);
+}
+
+static int realtext_read_close(AVFormatContext *s)
+{
+    RealTextContext *rt = s->priv_data;
+    ff_subtitles_queue_clean(&rt->q);
+    return 0;
+}
+
+AVInputFormat ff_realtext_demuxer = {
+    .name           = "realtext",
+    .long_name      = NULL_IF_CONFIG_SMALL("RealText subtitle format"),
+    .priv_data_size = sizeof(RealTextContext),
+    .read_probe     = realtext_probe,
+    .read_header    = realtext_read_header,
+    .read_packet    = realtext_read_packet,
+    .read_close     = realtext_read_close,
+    .flags          = AVFMT_GENERIC_INDEX,
+    .extensions     = "rt",
+};