[FFmpeg-devel] [PATCH 1/8] lavf: add internal demuxer helpers for subtitles.

[Clément Bœsch]

---
 libavformat/Makefile    |    1 +
 libavformat/subtitles.c |  102 +++++++++++++++++++++++++++++++++++++++++++++++
 libavformat/subtitles.h |   61 ++++++++++++++++++++++++++++
 3 files changed, 164 insertions(+)
 create mode 100644 libavformat/subtitles.c
 create mode 100644 libavformat/subtitles.h

diff --git a/libavformat/Makefile b/libavformat/Makefile
index 5e4f002..d53a3e0 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -19,6 +19,7 @@ OBJS = allformats.o         \
        riff.o               \
        sdp.o                \
        seek.o               \
+       subtitles.o          \
        utils.o              \
 
 OBJS-$(CONFIG_NETWORK)                   += network.o
diff --git a/libavformat/subtitles.c b/libavformat/subtitles.c
new file mode 100644
index 0000000..ba38842
--- /dev/null
+++ b/libavformat/subtitles.c
@@ -0,0 +1,102 @@
+/*
+ * 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
+ */
+
+#include "avformat.h"
+#include "subtitles.h"
+
+FFDemuxSubEntry *ff_subtitles_queue_insert_event(FFDemuxSubtitlesQueue *q,
+                                                 const uint8_t *event, int len,
+                                                 int merge)
+{
+    FFDemuxSubEntry *subs, *sub;
+
+    if (merge && q->nsub > 0) {
+        /* merge with previous event */
+
+        uint8_t *tmp;
+        sub = &q->subs[q->nsub - 1];
+        tmp = av_realloc(sub->event, sub->len + len + 1);
+        if (!tmp)
+            return NULL;
+        sub->event = tmp;
+        memcpy(sub->event + sub->len, event, len);
+        sub->len += len;
+    } else {
+        /* new event */
+
+        subs = av_realloc_f(q->subs, q->nsub + 1, sizeof(*q->subs));
+        if (!subs)
+            return NULL;
+        q->subs = subs;
+        sub = &subs[q->nsub++];
+        sub->event = av_malloc(len + 1);
+        sub->len   = len;
+        if (!sub->event)
+            return NULL;
+        memcpy(sub->event, event, len);
+    }
+    sub->event[sub->len] = 0;
+    return sub;
+}
+
+static int cmp_pkt_sub(const void *a, const void *b)
+{
+    return ((const FFDemuxSubEntry*)a)->start - ((const FFDemuxSubEntry*)b)->start;
+}
+
+void ff_subtitles_queue_finalize(FFDemuxSubtitlesQueue *q)
+{
+    int i;
+
+    for (i = 0; i < q->nsub; i++)
+        if (q->subs[i].duration == -1 && i < q->nsub - 1)
+            q->subs[i].duration = q->subs[i + 1].start - q->subs[i].start;
+    qsort(q->subs, q->nsub, sizeof(*q->subs), cmp_pkt_sub);
+}
+
+int ff_subtitles_queue_read_packet(FFDemuxSubtitlesQueue *q,
+                                   AVPacket *pkt, int i)
+{
+    int res;
+    FFDemuxSubEntry *sub = q->subs + i;
+
+    if (i == q->nsub)
+        return AVERROR_EOF;
+    res = av_new_packet(pkt, sub->len + 1);
+    if (res)
+        return res;
+    memcpy(pkt->data, sub->event, sub->len);
+    pkt->data[sub->len] = 0;
+    pkt->flags |= AV_PKT_FLAG_KEY;
+    pkt->pos = sub->pos;
+    pkt->pts = pkt->dts = sub->start;
+    pkt->duration = sub->duration;
+    return 0;
+}
+
+void ff_subtitles_queue_free(FFDemuxSubtitlesQueue *q)
+{
+    int i;
+
+    for (i = 0; i < q->nsub; i++)
+        av_freep(&q->subs[i].event);
+    av_freep(&q->subs);
+    q->nsub = 0;
+}
diff --git a/libavformat/subtitles.h b/libavformat/subtitles.h
new file mode 100644
index 0000000..993d026
--- /dev/null
+++ b/libavformat/subtitles.h
@@ -0,0 +1,61 @@
+/*
+ * 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
+ */
+
+#ifndef AVFORMAT_SUBTITLES_H
+#define AVFORMAT_SUBTITLES_H
+
+typedef struct {
+    uint8_t *event;     ///< allocated subtitle line, may not be zero-terminated
+    int len;            ///< subtitle event length
+    int64_t pos;        ///< offset position
+    int64_t start;      ///< timestamp start
+    int duration;       ///< event duration
+} FFDemuxSubEntry;
+
+typedef struct {
+    FFDemuxSubEntry *subs;
+    int nsub;
+} FFDemuxSubtitlesQueue;
+
+/**
+ * Insert a new subtitle event
+ */
+FFDemuxSubEntry *ff_subtitles_queue_insert_event(FFDemuxSubtitlesQueue *q,
+                                                 const uint8_t *event, int len,
+                                                 int merge);
+
+/**
+ * Set missing durations and sort subtitles by PTS
+ */
+void ff_subtitles_queue_finalize(FFDemuxSubtitlesQueue *q);
+
+/**
+ * Generic read_packet() callback for subtitles demuxers using this queue
+ * system
+ */
+int ff_subtitles_queue_read_packet(FFDemuxSubtitlesQueue *q,
+                                   AVPacket *pkt, int i);
+
+/**
+ * Remove and free all the events
+ */
+void ff_subtitles_queue_free(FFDemuxSubtitlesQueue *q);
+
+#endif /* AVFORMAT_SUBTITLES_H */
-- 
1.7.10.4