X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libavformat%2Fmpsubdec.c;h=ee53be17d652b24904a313b90b4a1cf2232df17d;hb=bc70684e74a185d7b80c8b80bdedda659cb581b8;hp=1236efa712f580ad2f3f16eb30d09391bfd0b6af;hpb=0c126431f9b290f5651ec62f45627632d94c51ea;p=ffmpeg

diff --git a/libavformat/mpsubdec.c b/libavformat/mpsubdec.c
index 1236efa712f..ee53be17d65 100644
--- a/libavformat/mpsubdec.c
+++ b/libavformat/mpsubdec.c
@@ -27,11 +27,13 @@
 #include "internal.h"
 #include "subtitles.h"
 
+#define TSBASE 10000000
+
 typedef struct {
     FFDemuxSubtitlesQueue q;
 } MPSubContext;
 
-static int mpsub_probe(AVProbeData *p)
+static int mpsub_probe(const AVProbeData *p)
 {
     const char *ptr     = p->buf;
     const char *ptr_end = p->buf + p->buf_size;
@@ -51,21 +53,55 @@ static int mpsub_probe(AVProbeData *p)
     return 0;
 }
 
+static int parse_line(const char *line, int64_t *value, int64_t *value2)
+{
+    int vi, p1, p2;
+
+    for (vi = 0; vi < 2; vi++) {
+        long long intval, fracval;
+        int n = av_sscanf(line, "%lld%n.%lld%n", &intval, &p1, &fracval, &p2);
+        if (n <= 0 || intval < INT64_MIN / TSBASE || intval > INT64_MAX / TSBASE)
+            return AVERROR_INVALIDDATA;
+
+        intval *= TSBASE;
+
+        if (n == 2) {
+            if (fracval < 0)
+                return AVERROR_INVALIDDATA;
+            for (;p2 - p1 < 7 + 1; p1--)
+                fracval *= 10;
+            for (;p2 - p1 > 7 + 1; p1++)
+                fracval /= 10;
+            if (intval > 0) intval = av_sat_add64(intval, fracval);
+            else            intval = av_sat_sub64(intval, fracval);
+            line += p2;
+        } else
+            line += p1;
+
+        *value = intval;
+
+        value = value2;
+    }
+
+    return 0;
+}
+
 static int mpsub_read_header(AVFormatContext *s)
 {
     MPSubContext *mpsub = s->priv_data;
     AVStream *st;
     AVBPrint buf;
-    AVRational pts_info = (AVRational){ 100, 1 }; // ts based by default
+    AVRational pts_info = (AVRational){ TSBASE, 1 }; // ts based by default
     int res = 0;
-    int multiplier = 100;
-    double current_pts = 0;
+    int64_t current_pts = 0;
+    int i;
+    int common_factor = 0;
 
     av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED);
 
     while (!avio_feof(s->pb)) {
         char line[1024];
-        double start, duration;
+        int64_t start, duration;
         int fps, len = ff_get_line(s->pb, line, sizeof(line));
 
         if (!len)
@@ -75,9 +111,8 @@ static int mpsub_read_header(AVFormatContext *s)
 
         if (sscanf(line, "FORMAT=%d", &fps) == 1 && fps > 3 && fps < 100) {
             /* frame based timing */
-            pts_info = (AVRational){ fps, 1 };
-            multiplier = 1;
-        } else if (sscanf(line, "%lf %lf", &start, &duration) == 2) {
+            pts_info = (AVRational){ TSBASE * fps, 1 };
+        } else if (parse_line(line, &start, &duration) >= 0) {
             AVPacket *sub;
             const int64_t pos = avio_tell(s->pb);
 
@@ -88,17 +123,41 @@ static int mpsub_read_header(AVFormatContext *s)
                     res = AVERROR(ENOMEM);
                     goto end;
                 }
-                sub->pts = (int64_t)(current_pts + start*multiplier);
-                sub->duration = (int)(duration * multiplier);
-                current_pts += (start + duration) * multiplier;
+                if (   current_pts < 0 && start < INT64_MIN - current_pts
+                    || current_pts > 0 && start > INT64_MAX - current_pts) {
+                    res = AVERROR_INVALIDDATA;
+                    goto end;
+                }
+                sub->pts = current_pts + start;
+                if (duration < 0 || sub->pts > INT64_MAX - duration) {
+                    res = AVERROR_INVALIDDATA;
+                    goto end;
+                }
+                sub->duration = duration;
+
+                common_factor = av_gcd(duration, common_factor);
+                common_factor = av_gcd(sub->pts, common_factor);
+
+                current_pts = sub->pts + duration;
                 sub->pos = pos;
             }
         }
     }
 
+    if (common_factor > 1) {
+        common_factor = av_gcd(pts_info.num, common_factor);
+        for (i = 0; i < mpsub->q.nb_subs; i++) {
+            mpsub->q.subs[i]->pts      /= common_factor;
+            mpsub->q.subs[i]->duration /= common_factor;
+        }
+        pts_info.num /= common_factor;
+    }
+
     st = avformat_new_stream(s, NULL);
-    if (!st)
-        return AVERROR(ENOMEM);
+    if (!st) {
+        res = AVERROR(ENOMEM);
+        goto end;
+    }
     avpriv_set_pts_info(st, 64, pts_info.den, pts_info.num);
     st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;
     st->codecpar->codec_id   = AV_CODEC_ID_TEXT;
@@ -106,6 +165,9 @@ static int mpsub_read_header(AVFormatContext *s)
     ff_subtitles_queue_finalize(s, &mpsub->q);
 
 end:
+    if (res < 0)
+        ff_subtitles_queue_clean(&mpsub->q);
+
     av_bprint_finalize(&buf, NULL);
     return res;
 }
@@ -131,7 +193,7 @@ static int mpsub_read_close(AVFormatContext *s)
     return 0;
 }
 
-AVInputFormat ff_mpsub_demuxer = {
+const AVInputFormat ff_mpsub_demuxer = {
     .name           = "mpsub",
     .long_name      = NULL_IF_CONFIG_SMALL("MPlayer subtitles"),
     .priv_data_size = sizeof(MPSubContext),