X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libavformat%2Fmpegts.c;h=8a84e5cc1903dda1877e4a28bc84e656a3257e2e;hb=76ef18fd3910a5b479a3d9e584a0adc13f0d84ee;hp=e7bbf3e488980c27c392802b1b49014621535e69;hpb=f05f210526a3dc2d9fa6b1c228e3907ebd1d43c6;p=ffmpeg

diff --git a/libavformat/mpegts.c b/libavformat/mpegts.c
index e7bbf3e4889..8a84e5cc190 100644
--- a/libavformat/mpegts.c
+++ b/libavformat/mpegts.c
@@ -56,6 +56,9 @@
         (prev_dividend) = (dividend);                                          \
     } while (0)
 
+#define PROBE_PACKET_MAX_BUF 8192
+#define PROBE_PACKET_MARGIN 5
+
 enum MpegTSFilterType {
     MPEGTS_PES,
     MPEGTS_SECTION,
@@ -594,28 +597,42 @@ static int analyze(const uint8_t *buf, int size, int packet_size,
     return best_score - FFMAX(stat_all - 10*best_score, 0)/10;
 }
 
-/* autodetect fec presence. Must have at least 1024 bytes  */
-static int get_packet_size(const uint8_t *buf, int size)
+/* autodetect fec presence */
+static int get_packet_size(AVFormatContext* s)
 {
     int score, fec_score, dvhs_score;
+    int margin;
+    int ret;
 
-    if (size < (TS_FEC_PACKET_SIZE * 5 + 1))
-        return AVERROR_INVALIDDATA;
+    /*init buffer to store stream for probing */
+    uint8_t buf[PROBE_PACKET_MAX_BUF] = {0};
+    int buf_size = 0;
 
-    score      = analyze(buf, size, TS_PACKET_SIZE,      0);
-    dvhs_score = analyze(buf, size, TS_DVHS_PACKET_SIZE, 0);
-    fec_score  = analyze(buf, size, TS_FEC_PACKET_SIZE,  0);
-    av_log(NULL, AV_LOG_TRACE, "score: %d, dvhs_score: %d, fec_score: %d \n",
-            score, dvhs_score, fec_score);
-
-    if (score > fec_score && score > dvhs_score)
-        return TS_PACKET_SIZE;
-    else if (dvhs_score > score && dvhs_score > fec_score)
-        return TS_DVHS_PACKET_SIZE;
-    else if (score < fec_score && dvhs_score < fec_score)
-        return TS_FEC_PACKET_SIZE;
-    else
-        return AVERROR_INVALIDDATA;
+    while (buf_size < PROBE_PACKET_MAX_BUF) {
+        ret = avio_read_partial(s->pb, buf + buf_size, PROBE_PACKET_MAX_BUF - buf_size);
+        if (ret < 0)
+            return AVERROR_INVALIDDATA;
+        buf_size += ret;
+
+        score      = analyze(buf, buf_size, TS_PACKET_SIZE,      0);
+        dvhs_score = analyze(buf, buf_size, TS_DVHS_PACKET_SIZE, 0);
+        fec_score  = analyze(buf, buf_size, TS_FEC_PACKET_SIZE,  0);
+        av_log(s, AV_LOG_TRACE, "Probe: %d, score: %d, dvhs_score: %d, fec_score: %d \n",
+            buf_size, score, dvhs_score, fec_score);
+
+        margin = mid_pred(score, fec_score, dvhs_score);
+
+        if (buf_size < PROBE_PACKET_MAX_BUF)
+            margin += PROBE_PACKET_MARGIN; /*if buffer not filled */
+
+        if (score > margin)
+            return TS_PACKET_SIZE;
+        else if (dvhs_score > margin)
+            return TS_DVHS_PACKET_SIZE;
+        else if (fec_score > margin)
+            return TS_FEC_PACKET_SIZE;
+    }
+    return AVERROR_INVALIDDATA;
 }
 
 typedef struct SectionHeader {
@@ -2851,7 +2868,7 @@ static int handle_packets(MpegTSContext *ts, int64_t nb_packets)
     return ret;
 }
 
-static int mpegts_probe(AVProbeData *p)
+static int mpegts_probe(const AVProbeData *p)
 {
     const int size = p->buf_size;
     int maxscore = 0;
@@ -2933,8 +2950,6 @@ static int mpegts_read_header(AVFormatContext *s)
 {
     MpegTSContext *ts = s->priv_data;
     AVIOContext *pb   = s->pb;
-    uint8_t buf[8 * 1024] = {0};
-    int len;
     int64_t pos, probesize = s->probesize;
 
     s->internal->prefer_codec_framerate = 1;
@@ -2942,10 +2957,8 @@ static int mpegts_read_header(AVFormatContext *s)
     if (ffio_ensure_seekback(pb, probesize) < 0)
         av_log(s, AV_LOG_WARNING, "Failed to allocate buffers for seekback\n");
 
-    /* read the first 8192 bytes to get packet size */
     pos = avio_tell(pb);
-    len = avio_read(pb, buf, sizeof(buf));
-    ts->raw_packet_size = get_packet_size(buf, len);
+    ts->raw_packet_size = get_packet_size(s);
     if (ts->raw_packet_size <= 0) {
         av_log(s, AV_LOG_WARNING, "Could not detect TS packet size, defaulting to non-FEC/DVHS\n");
         ts->raw_packet_size = TS_PACKET_SIZE;