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[ffmpeg] / libavformat / assdec.c

diff --git a/libavformat/assdec.c b/libavformat/assdec.c
index ff1009c1cebb4237b6a0e19ef7440ec92bd4a87e..e04d92ae659280fab9333e7a3ef0d6b06ed5690b 100644 (file)
--- a/libavformat/assdec.c
+++ b/libavformat/assdec.c
@@ -76,7 +76,7 @@ static int read_header(AVFormatContext *s, AVFormatParameters *ap)
 {
     int i, len, header_remaining;
     ASSContext *ass = s->priv_data;
-    ByteIOContext *pb = s->pb;
+    AVIOContext *pb = s->pb;
     AVStream *st;
     int allocated[2]={0};
     uint8_t *p, **dst[2]={0};
@@ -162,13 +162,53 @@ static int read_packet(AVFormatContext *s, AVPacket *pkt)
     return 0;
 }
 
-AVInputFormat ass_demuxer = {
-    "ass",
-    NULL_IF_CONFIG_SMALL("Advanced SubStation Alpha subtitle format"),
-    sizeof(ASSContext),
-    probe,
-    read_header,
-    read_packet,
-    read_close,
-//    read_seek,
+static int read_seek2(AVFormatContext *s, int stream_index,
+                      int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
+{
+    ASSContext *ass = s->priv_data;
+
+    if (flags & AVSEEK_FLAG_BYTE) {
+        return AVERROR_NOTSUPP;
+    } else if (flags & AVSEEK_FLAG_FRAME) {
+        if (ts < 0 || ts >= ass->event_count)
+            return AVERROR(ERANGE);
+        ass->event_index = ts;
+    } else {
+        int i, idx = -1;
+        int64_t min_ts_diff = INT64_MAX;
+        if (stream_index == -1) {
+            AVRational time_base = s->streams[0]->time_base;
+            ts = av_rescale_q(ts, AV_TIME_BASE_Q, time_base);
+            min_ts = av_rescale_rnd(min_ts, time_base.den,
+                                    time_base.num * (int64_t)AV_TIME_BASE,
+                                    AV_ROUND_UP);
+            max_ts = av_rescale_rnd(max_ts, time_base.den,
+                                    time_base.num * (int64_t)AV_TIME_BASE,
+                                    AV_ROUND_DOWN);
+        }
+        /* TODO: ass->event[] is sorted by pts so we could do a binary search */
+        for (i=0; i<ass->event_count; i++) {
+            int64_t pts = get_pts(ass->event[i]);
+            int64_t ts_diff = FFABS(pts - ts);
+            if (pts >= min_ts && pts <= max_ts && ts_diff < min_ts_diff) {
+                min_ts_diff = ts_diff;
+                idx = i;
+            }
+        }
+        if (idx < 0)
+            return AVERROR(ERANGE);
+        ass->event_index = idx;
+    }
+    return 0;
+}
+
+AVInputFormat ff_ass_demuxer = {
+    .name           = "ass",
+    .long_name      = NULL_IF_CONFIG_SMALL("Advanced SubStation Alpha subtitle format"),
+    .priv_data_size = sizeof(ASSContext),
+    .read_probe     = probe,
+    .read_header    = read_header,
+    .read_packet    = read_packet,
+    .read_close     = read_close,
+    .read_seek2     = read_seek2,
 };