[FFmpeg-devel] [PATCH] RealText demuxer and decoder.

Clément Bœsch ubitux at gmail.com
Sun Jun 17 01:01:16 CEST 2012


On Sat, Jun 16, 2012 at 10:50:18PM +0000, Paul B Mahol wrote:
[...]
> > diff --git a/libavformat/Makefile b/libavformat/Makefile
> > index 0771271..5f330dc 100644
> > --- a/libavformat/Makefile
> > +++ b/libavformat/Makefile
> > @@ -261,6 +261,7 @@ OBJS-$(CONFIG_ROQ_MUXER)                 += idroqenc.o
> > rawenc.o
> >  OBJS-$(CONFIG_RSO_DEMUXER)               += rsodec.o rso.o pcm.o
> >  OBJS-$(CONFIG_RSO_MUXER)                 += rsoenc.o rso.o
> >  OBJS-$(CONFIG_RPL_DEMUXER)               += rpl.o
> > +OBJS-$(CONFIG_REALTEXT_DEMUXER)          += realtextdec.o
> 
> nit: Aren't entries sorted?

Ah yeah I renamed from RT to REALTEXT and forgot to re-order... Fixed.

> >  OBJS-$(CONFIG_RTP_MUXER)                 += rtp.o         \
> >                                              rtpenc_aac.o     \
> >                                              rtpenc_latm.o    \
> > diff --git a/libavformat/allformats.c b/libavformat/allformats.c
> > index b383218..1cff964 100644
> > --- a/libavformat/allformats.c
> > +++ b/libavformat/allformats.c
> > @@ -203,6 +203,7 @@ void av_register_all(void)
> >      REGISTER_MUXDEMUX (ROQ, roq);
> >      REGISTER_DEMUXER  (RPL, rpl);
> >      REGISTER_MUXDEMUX (RSO, rso);
> > +    REGISTER_DEMUXER  (REALTEXT, realtext);
> 
> ditto.

Thanks, fixed.

> >      REGISTER_MUXDEMUX (RTP, rtp);
> >      REGISTER_MUXDEMUX (RTSP, rtsp);
> >      REGISTER_DEMUXER  (SAMI, sami);
> > +        if (n == 0)
> > +            break;
> > +
> > +        if (!av_strncasecmp(buf.str, "<window", 7)) {
> > +            /* save header to extradata */
> > +            char *p = get_attr_ptr(buf.str, "duration");
> > +
> > +            if (p)
> > +                duration = read_ts(p);
> > +            st->codec->extradata = av_strdup(buf.str);
> 
> This may fail.

Check added.

[...]

-- 
Clément B.
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From bfbca901af5ad2b32680356330704a1f3bb45b5b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Cl=C3=A9ment=20B=C5=93sch?= <ubitux at gmail.com>
Date: Sun, 17 Jun 2012 00:33:10 +0200
Subject: [PATCH 9/9] RealText demuxer and decoder.

FIXME: bump minor in lavc & lavf
---
 doc/general.texi            |    1 +
 libavcodec/Makefile         |    1 +
 libavcodec/allcodecs.c      |    1 +
 libavcodec/avcodec.h        |    1 +
 libavcodec/realtextdec.c    |   81 ++++++++++++++++++++
 libavformat/Makefile        |    1 +
 libavformat/allformats.c    |    1 +
 libavformat/realtextdec.c   |  174 +++++++++++++++++++++++++++++++++++++++++++
 tests/fate/subtitles.mak    |    3 +
 tests/ref/fate/sub-realtext |    1 +
 10 files changed, 265 insertions(+)
 create mode 100644 libavcodec/realtextdec.c
 create mode 100644 libavformat/realtextdec.c
 create mode 100644 tests/ref/fate/sub-realtext

diff --git a/doc/general.texi b/doc/general.texi
index def03e3..72d09ae 100644
--- a/doc/general.texi
+++ b/doc/general.texi
@@ -842,6 +842,7 @@ 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
+ at 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
diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 668b4cd..e14b038 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -378,6 +378,7 @@ 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
diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
index 1eda64f..cf9e32e 100644
--- a/libavcodec/allcodecs.c
+++ b/libavcodec/allcodecs.c
@@ -402,6 +402,7 @@ 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);
diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index 952d846..7e874ad 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -427,6 +427,7 @@ 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.
diff --git a/libavcodec/realtextdec.c b/libavcodec/realtextdec.c
new file mode 100644
index 0000000..512bfc1
--- /dev/null
+++ b/libavcodec/realtextdec.c
@@ -0,0 +1,81 @@
+/*
+ * 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);
+    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,
+};
diff --git a/libavformat/Makefile b/libavformat/Makefile
index 0771271..a02fb01 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -253,6 +253,7 @@ 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
diff --git a/libavformat/allformats.c b/libavformat/allformats.c
index b383218..77ae1dc 100644
--- a/libavformat/allformats.c
+++ b/libavformat/allformats.c
@@ -198,6 +198,7 @@ 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);
diff --git a/libavformat/realtextdec.c b/libavformat/realtextdec.c
new file mode 100644
index 0000000..ab77b54
--- /dev/null
+++ b/libavformat/realtextdec.c
@@ -0,0 +1,174 @@
+/*
+ * 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 {
+    int sid;
+    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 extract_next_chunk(AVIOContext *pb, AVBPrint *buf, char *c)
+{
+    int i = 0;
+    char end_chr;
+
+    if (!*c) // cached char?
+        *c = avio_r8(pb);
+    if (!*c)
+        return 0;
+
+    end_chr = *c == '<' ? '>' : '<';
+    do {
+        av_bprint_chars(buf, *c, 1);
+        *c = avio_r8(pb);
+        i++;
+    } while (*c != end_chr && *c);
+    if (end_chr == '>') {
+        av_bprint_chars(buf, '>', 1);
+        *c = 0;
+    }
+    return i;
+}
+
+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 char *get_attr_ptr(const char *s, const char *tag)
+{
+    char *p = av_stristr(s, tag);
+    if (p) {
+        p += strlen(tag);
+        if (*p == '=') p++;
+        if (*p == '"') p++;
+    }
+    return p;
+}
+
+static int realtext_read_header(AVFormatContext *s)
+{
+    char c = 0;
+    int duration = read_ts("60"); // default duration is 60 seconds
+    RealTextContext *rt = s->priv_data;
+    AVStream *st = avformat_new_stream(s, NULL);
+    AVBPrint buf;
+
+    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, 4096);
+
+    while (!url_feof(s->pb)) {
+        FFDemuxSubEntry *sub;
+        const int64_t pos = avio_tell(s->pb) - (c != 0);
+        int merge, n = extract_next_chunk(s->pb, &buf, &c);
+
+        if (n == 0)
+            break;
+
+        if (!av_strncasecmp(buf.str, "<window", 7)) {
+            /* save header to extradata */
+            char *p = get_attr_ptr(buf.str, "duration");
+
+            if (p)
+                duration = read_ts(p);
+            st->codec->extradata = av_strdup(buf.str);
+            if (!st->codec->extradata)
+                return AVERROR(ENOMEM);
+            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 */
+            merge = !av_strncasecmp(buf.str, "<time", 5) ? 0 : 1;
+            sub = ff_subtitles_queue_insert_event(&rt->q, buf.str, buf.len, merge);
+            if (!sub)
+                return AVERROR(ENOMEM);
+            if (!merge) {
+                const char *begin = get_attr_ptr(buf.str, "begin");
+                const char *end   = get_attr_ptr(buf.str, "end");
+
+                sub->pos      = pos;
+                sub->start    = begin ? read_ts(begin) : 0;
+                sub->duration = end ? (read_ts(end) - sub->start) : duration;
+            }
+        }
+        av_bprint_clear(&buf);
+    }
+    ff_subtitles_queue_finalize(&rt->q);
+    av_bprint_finalize(&buf, NULL);
+    return 0;
+}
+
+static int realtext_read_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    RealTextContext *rt = s->priv_data;
+    return ff_subtitles_queue_read_packet(&rt->q, pkt, rt->sid++);
+}
+
+static int realtext_read_close(AVFormatContext *s)
+{
+    RealTextContext *rt = s->priv_data;
+    ff_subtitles_queue_free(&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",
+};
diff --git a/tests/fate/subtitles.mak b/tests/fate/subtitles.mak
index 538e352..f2a68e1 100644
--- a/tests/fate/subtitles.mak
+++ b/tests/fate/subtitles.mak
@@ -10,5 +10,8 @@ fate-sub-sami: CMD = md5 -i $(SAMPLES)/sub/SAMI_capability_tester.smi -f ass
 FATE_SUBTITLES += fate-sub-srt
 fate-sub-srt: CMD = md5 -i $(SAMPLES)/sub/SubRip_capability_tester.srt -f ass
 
+FATE_SUBTITLES += fate-sub-realtext
+fate-sub-realtext: CMD = md5 -i $(SAMPLES)/sub/RealText_capability_tester.rt -f ass
+
 FATE_SAMPLES_FFMPEG += $(FATE_SUBTITLES)
 fate-subtitles: $(FATE_SUBTITLES)
diff --git a/tests/ref/fate/sub-realtext b/tests/ref/fate/sub-realtext
new file mode 100644
index 0000000..42ac3bb
--- /dev/null
+++ b/tests/ref/fate/sub-realtext
@@ -0,0 +1 @@
+5366f62be001f6fd4a7f48893828bf51
-- 
1.7.10.4

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