SAMI demuxer and decoder.

1 files changed, 132 insertions, 0 deletions

diff --git a/libavformat/samidec.c b/libavformat/samidec.c
new file mode 100644
index 0000000000..5995d86fcf
--- /dev/null
+++ b/libavformat/samidec.c
@@ -0,0 +1,132 @@
+/*
+ * 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
+ * SAMI subtitle demuxer
+ * @see http://msdn.microsoft.com/en-us/library/ms971327.aspx
+ */
+
+#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;
+} SAMIContext;
+
+static int sami_probe(AVProbeData *p)
+{
+    const unsigned char *ptr = p->buf;
+
+    if (AV_RB24(ptr) == 0xEFBBBF)
+        ptr += 3;  /* skip UTF-8 BOM */
+    return !strncmp(ptr, "<SAMI>", 6) ? AVPROBE_SCORE_MAX : 0;
+}
+
+static int sami_read_header(AVFormatContext *s)
+{
+    SAMIContext *sami = s->priv_data;
+    AVStream *st = avformat_new_stream(s, NULL);
+    AVBPrint buf, hdr_buf;
+    char c = 0;
+    int res = 0, got_first_sync_point = 0;
+
+    if (!st)
+        return AVERROR(ENOMEM);
+    avpriv_set_pts_info(st, 64, 1, 1000);
+    st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
+    st->codec->codec_id   = CODEC_ID_SAMI;
+
+    av_bprint_init(&buf,     0, AV_BPRINT_SIZE_UNLIMITED);
+    av_bprint_init(&hdr_buf, 0, AV_BPRINT_SIZE_UNLIMITED);
+
+    while (!url_feof(s->pb)) {
+        AVPacket *sub;
+        const int64_t pos = avio_tell(s->pb) - (c != 0);
+        int is_sync, n = ff_smil_extract_next_chunk(s->pb, &buf, &c);
+
+        if (n == 0)
+            break;
+
+        is_sync = !av_strncasecmp(buf.str, "<SYNC", 5);
+        if (is_sync)
+            got_first_sync_point = 1;
+
+        if (!got_first_sync_point) {
+            av_bprintf(&hdr_buf, "%s", buf.str);
+        } else {
+            sub = ff_subtitles_queue_insert(&sami->q, buf.str, buf.len, !is_sync);
+            if (!sub) {
+                res = AVERROR(ENOMEM);
+                goto end;
+            }
+            if (is_sync) {
+                const char *p = ff_smil_get_attr_ptr(buf.str, "Start");
+                sub->pos      = pos;
+                sub->pts      = p ? strtol(p, NULL, 10) : 0;
+                sub->duration = -1;
+            }
+        }
+        av_bprint_clear(&buf);
+    }
+
+    st->codec->extradata_size = hdr_buf.len + 1;
+    av_bprint_finalize(&hdr_buf, (char **)&st->codec->extradata);
+    if (!st->codec->extradata) {
+        st->codec->extradata_size = 0;
+        res = AVERROR(ENOMEM);
+        goto end;
+    }
+
+    ff_subtitles_queue_finalize(&sami->q);
+
+end:
+    av_bprint_finalize(&buf, NULL);
+    return res;
+}
+
+static int sami_read_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    SAMIContext *sami = s->priv_data;
+    return ff_subtitles_queue_read_packet(&sami->q, pkt);
+}
+
+static int sami_read_close(AVFormatContext *s)
+{
+    SAMIContext *sami = s->priv_data;
+    ff_subtitles_queue_clean(&sami->q);
+    return 0;
+}
+
+AVInputFormat ff_sami_demuxer = {
+    .name           = "sami",
+    .long_name      = NULL_IF_CONFIG_SMALL("SAMI subtitle format"),
+    .priv_data_size = sizeof(SAMIContext),
+    .read_probe     = sami_probe,
+    .read_header    = sami_read_header,
+    .read_packet    = sami_read_packet,
+    .read_close     = sami_read_close,
+    .flags          = AVFMT_GENERIC_INDEX,
+    .extensions     = "smi,sami",
+};