SubViewer demuxer and decoder.

1 files changed, 177 insertions, 0 deletions

diff --git a/libavformat/subviewerdec.c b/libavformat/subviewerdec.c
new file mode 100644
index 0000000000..ac68fc151d
--- /dev/null
+++ b/libavformat/subviewerdec.c
@@ -0,0 +1,177 @@
+/*
+ * 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
+ * SubViewer subtitle demuxer
+ * @see https://en.wikipedia.org/wiki/SubViewer
+ */
+
+#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;
+} SubViewerContext;
+
+static int subviewer_probe(AVProbeData *p)
+{
+    char c;
+    const unsigned char *ptr = p->buf;
+
+    if (AV_RB24(ptr) == 0xEFBBBF)
+        ptr += 3;  /* skip UTF-8 BOM */
+    if (sscanf(ptr, "%*u:%*u:%*u.%*u,%*u:%*u:%*u.%*u%c", &c) == 1)
+        return AVPROBE_SCORE_MAX/2;
+    if (!strncmp(ptr, "[INFORMATION]", 13))
+        return AVPROBE_SCORE_MAX/3;
+    return 0;
+}
+
+static int read_ts(const char *s, int64_t *start, int *duration)
+{
+    int64_t end;
+    int hh1, mm1, ss1, ms1;
+    int hh2, mm2, ss2, ms2;
+
+    if (sscanf(s, "%u:%u:%u.%u,%u:%u:%u.%u",
+               &hh1, &mm1, &ss1, &ms1, &hh2, &mm2, &ss2, &ms2) == 8) {
+        end    = (hh2*3600 + mm2*60 + ss2) * 100 + ms2;
+        *start = (hh1*3600 + mm1*60 + ss1) * 100 + ms1;
+        *duration = end - *start;
+        return 0;
+    }
+    return -1;
+}
+
+static int subviewer_read_header(AVFormatContext *s)
+{
+    SubViewerContext *subviewer = s->priv_data;
+    AVStream *st = avformat_new_stream(s, NULL);
+    AVBPrint header;
+    int res = 0;
+
+    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_SUBVIEWER;
+
+    av_bprint_init(&header, 0, AV_BPRINT_SIZE_UNLIMITED);
+
+    while (!url_feof(s->pb)) {
+        char line[2048];
+        const int64_t pos = avio_tell(s->pb);
+        int len = ff_get_line(s->pb, line, sizeof(line));
+
+        if (!len)
+            break;
+
+        if (line[0] == '[' && strncmp(line, "[br]", 4)) {
+
+            /* ignore event style, XXX: add to side_data? */
+            if (strstr(line, "[COLF]") || strstr(line, "[SIZE]") ||
+                strstr(line, "[FONT]") || strstr(line, "[STYLE]"))
+                continue;
+
+            if (!st->codec->extradata) { // header not finalized yet
+                av_bprintf(&header, "%s", line);
+                if (!strncmp(line, "[END INFORMATION]", 17) || !strncmp(line, "[SUBTITLE]", 10)) {
+                    /* end of header */
+                    av_bprint_finalize(&header, (char **)&st->codec->extradata);
+                    if (!st->codec->extradata) {
+                        res = AVERROR(ENOMEM);
+                        goto end;
+                    }
+                    st->codec->extradata_size = header.len + 1;
+                } else if (strncmp(line, "[INFORMATION]", 13)) {
+                    /* assume file metadata at this point */
+                    int i, j = 0;
+                    char key[32], value[128];
+
+                    for (i = 1; i < sizeof(key) - 1 && line[i] && line[i] != ']'; i++)
+                        key[i - 1] = av_tolower(line[i]);
+                    key[i - 1] = 0;
+
+                    if (line[i] == ']')
+                        i++;
+                    while (line[i] == ' ')
+                        i++;
+                    while (j < sizeof(value) - 1 && line[i] && !strchr("]\r\n", line[i]))
+                        value[j++] = line[i++];
+                    value[j] = 0;
+
+                    av_dict_set(&s->metadata, key, value, 0);
+                }
+            }
+        } else {
+            int64_t pts_start = AV_NOPTS_VALUE;
+            int duration = -1;
+            int timed_line = !read_ts(line, &pts_start, &duration);
+            AVPacket *sub;
+
+            sub = ff_subtitles_queue_insert(&subviewer->q, line, len, !timed_line);
+            if (!sub) {
+                res = AVERROR(ENOMEM);
+                goto end;
+            }
+            if (timed_line) {
+                sub->pos = pos;
+                sub->pts = pts_start;
+                sub->duration = duration;
+            }
+        }
+    }
+
+    ff_subtitles_queue_finalize(&subviewer->q);
+
+end:
+    av_bprint_finalize(&header, NULL);
+    return res;
+}
+
+static int subviewer_read_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    SubViewerContext *subviewer = s->priv_data;
+    return ff_subtitles_queue_read_packet(&subviewer->q, pkt);
+}
+
+static int subviewer_read_close(AVFormatContext *s)
+{
+    SubViewerContext *subviewer = s->priv_data;
+    ff_subtitles_queue_clean(&subviewer->q);
+    return 0;
+}
+
+AVInputFormat ff_subviewer_demuxer = {
+    .name           = "subviewer",
+    .long_name      = NULL_IF_CONFIG_SMALL("SubViewer subtitle format"),
+    .priv_data_size = sizeof(SubViewerContext),
+    .read_probe     = subviewer_probe,
+    .read_header    = subviewer_read_header,
+    .read_packet    = subviewer_read_packet,
+    .read_close     = subviewer_read_close,
+    .flags          = AVFMT_GENERIC_INDEX,
+    .extensions     = "sub",
+};